U.S. patent number RE29,112 [Application Number 05/638,204] was granted by the patent office on 1977-01-11 for methods of forming a fiber reinforced pipe on an inflatable mandrel.
This patent grant is currently assigned to Ciba-Geigy Corporation. Invention is credited to J. Warne Carter.
United States Patent |
RE29,112 |
Carter |
January 11, 1977 |
Methods of forming a fiber reinforced pipe on an inflatable
mandrel
Abstract
A method and apparatus is provided for continuously making fiber
reinforced plastic pipe in which a conveyor tube is formed on an
axially fixed hollow rotatable mandrel. A plurality of bands of
resin impregnated fiber elements are wound on the conveyor tube as
it advances to provide the pipe assembly. The terminal end of the
generated pipe assembly is sealed with a plug. A fluid under
pressure is fed through the hollow mandrel and out the forward end
of the mandrel into a chamber formed by the generated pipe
assembly, the plug, and a fluid sealing means within the pipe
assembly being generated, thereby causing the pipe assembly to
advance.
Inventors: |
Carter; J. Warne (Summit,
NJ) |
Assignee: |
Ciba-Geigy Corporation
(Ardsley, NY)
|
Family
ID: |
27500141 |
Appl.
No.: |
05/638,204 |
Filed: |
December 5, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
577035 |
Sep 2, 1966 |
3507412 |
|
|
|
387372 |
Aug 4, 1964 |
|
|
|
|
705564 |
Feb 14, 1968 |
|
|
|
Reissue of: |
824153 |
May 13, 1969 |
03700519 |
Oct 24, 1972 |
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Current U.S.
Class: |
156/156; 138/172;
156/247; 156/289; 156/173; 156/392; 156/287 |
Current CPC
Class: |
B29C
53/60 (20130101); B29C 53/607 (20130101); B29C
53/8091 (20130101); B29C 53/825 (20130101); F16L
9/16 (20130101); F16L 55/134 (20130101); F16L
55/136 (20130101); B29C 2793/009 (20130101); B29L
2009/00 (20130101) |
Current International
Class: |
B29C
53/00 (20060101); B29C 53/82 (20060101); B29C
53/60 (20060101); F16L 9/16 (20060101); B29C
53/80 (20060101); F16L 55/134 (20060101); F16L
55/10 (20060101); F16L 55/136 (20060101); F16L
9/00 (20060101); B65H 081/06 (); B65C 003/26 () |
Field of
Search: |
;156/156,169,171,172,173,191,195,287,289,392,429,431,499,537,247
;138/172 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Weston; Caleb
Attorney, Agent or Firm: Falber; Harry
Parent Case Text
This application is a continuation-in-part of application Ser. No.
577,035, now Pat. No. 3,507,412, filed Sept. 2, 1966, which in turn
is a continuation-in-part of application Ser. No. 387,372, filed
Aug. 4, 1964, now abandoned, of which application Ser. No. 705,564,
filed Feb. 14, 1968 is a continuation.
Claims
I claim:
1. A method for continuously making substantially rigid, fiber
reinforced plastic pipe comprising providing an air impervious
conveyor tube on an axially fixed, hollow mandrel, the mandrel
being provided with means to furnish an air seal with the interior
of the conveyor tube as the conveyor tube is continuously advanced
over the mandrel, winding a plurality of bands of thermosetting
resin composition impregnated continuous fiber elements onto the
conveyor tube to provide a pipe assembly, rotating the pipe
assembly with respect to the mandrel, curing the thermosetting
resin composition, providing an air seal at the forward end of the
pipe assembly being generated, linearly advancing the pipe assembly
by directing air under pressure through the mandrel and out from
the forward end thereof into the interior of the pipe assembly,
.[.and.]. controlling the rate of linear advancement of the pipe
assembly.[...]. .Iadd.and providing a temporary seal to prevent the
loss of pressure within the advancing pipe assembly when a section
thereof is cut and to allow providing an air seal at the forward
end of the pipe assembling being generated. .Iaddend.
2. A method according to claim 1, wherein a resin tube is provided
beneath the bands of thermosetting resin composition impregnated
continuous fiber elements.
3. A method according to claim 1, wherein the air impervious
conveyor tube is of a resin composition.
4. A method according to claim 1, wherein providing an air
impervious conveyor tube on the mandrel comprises forming on the
mandrel a tube of a thermosetting resin composition, and at least
partially curing the resin composition prior to winding a band of
thermosetting resin composition impregnated continuous fiber
elements thereon, said tube being integrated into the pipe assembly
to furnish a resin liner.
5. A method according to claim 1, wherein providing an air
impervious conveyor tube on the mandrel comprises impregnating a
continuous carrier strip with a thermosetting resin composition to
provide the resin composition on both sides of the carrier strip,
providing a portion of the length of the mandrel with a parting
material, winding the resin impregnated carrier strip on said
portion of the mandrel to form a tube, and at least partially
curing the resin composition prior to winding a band of
thermosetting resin composition impregnated continuous fiber
elements thereon, said tube being integrated into the pipe assembly
to furnish a resin liner.
6. A method according to claim 1 wherein providing an air
impervious conveyor tube on the mandrel comprises impregnating a
continuous carrier strip with a thermosetting resin composition, at
least partially curing said resin composition prior to winding it
on the mandrel, providing a portion of the length of the mandrel
with a parting material, winding the at least partially cured resin
impregnated carrier strip on said mandrel to form a tube; sealing
the wall of said tube to make it air impervious prior to winding a
band of thermosetting resin composition continuous fiber elements
thereon, said tube being integrated into the pipe.
7. The method according to claim 6 wherein said thermosetting resin
composition impregnated carrier strip is cured to a B-stage prior
to being wound on said mandrel, said sealing comprising heating
said resin composition impregnated strip material after it is wound
on said mandrel to a temperature sufficient to cause said B-stage
resin to soften and fuse with the resin composition on adjacent
strips of said strip material, thereby forming said air impervious
tube.
8. The method according to claim 6 wherein said sealing is provided
by applying a continuous coating of a resin composition over the
tube, and at least partially curing said coating prior to
overwinding a band of thermosetting resin composition impregnated
continuous fiber elements thereon.
9. A method according to claim 1, wherein the air impervious
conveyor tube is formed to enable the removal thereof from within
the completed pipe assembly.
10. A method according to claim 1, wherein providing an air
impervious conveyor tube on the mandrel comprises forming the tube
on the mandrel, the tube having a layer of parting material at the
exterior thereof whereby the conveyor tube may be removed after the
pipe assembly is completed.
11. A method according to claim 1, wherein providing an air
impervious conveyor tube on the mandrel comprises forming the tube
on the mandrel, the tube having a layer of parting material at the
exterior thereof, the tube including a stripping wire adjacent the
layer of parting material, and applying tension to the stripping
wire to remove the conveyor tube after the pipe assembly has been
completed.
12. A method according to claim 1 wherein the air impervious
conveyor tube is formed with a resinous outer liner which becomes
integral with the pipe and a removable inner liner.
13. The method according to claim 12 wherein the outer surface of
said inner liner is coated with a layer of a solvent activated
parting agent, whereby said inner liner is released by contacting
the parting agent with the solvent for the parting agent.
14. A method according to claim 1 wherein producing an air
impervious tube on the mandrel comprises providing a tape having an
inner surface which is nonadhesive to said mandrel and a coating of
a solvent activated parting agent on the outer surface thereof,
helically winding a tape about said mandrel to provide a tube with
the inner surface of said tape adjacent said mandrel, coating the
outer surface of said tube with a thermosetting resin composition
and at least partially curing said resin composition prior to
winding a band of thermosetting resin composition impregnated
continuous fiber elements thereon.
15. A method according to claim 14 wherein the parting agent is
activated by water.
16. A method according to claim 14 wherein the tape is of paper
coated on one side with a water-soluble adhesive.
17. A method according to claim 1, wherein winding a plurality of
bands of thermosetting resin composition impregnated continuous
fiber elements onto the conveyor tube comprises winding one set of
bands having the fiber elements thereof at a high angle with
respect to the longitudinal axis of the pipe assembly alternated
with a second set of bands wound with the fiber elements at a lower
angle and of opposite hand, rotating the pipe assembly by the
winding of one of said sets of bands.
18. A method according to claim 1, wherein winding a plurality of
bands of thermosetting resin composition impregnated continuous
fiber elements onto the conveyor tube comprises winding one set of
bands having the fiber elements thereof at a high angle with
respect to the longitudinal axis of the pipe assembly alternated
with a second set of bands wound with the fiber elements at a lower
angle and of opposite hand, the fiber elements of adjacent pairs of
hands being impregnated by a resin composition in the same
bath.
19. A method according to claim 1 which includes providing an
inflatable air seal .Iadd.as said temporary seal .Iaddend.within
the pipe assembly rearward of the forward end of the pipe assembly,
the air seal when inflated being movable with the advancing pipe
assembly, inflating the air seal and cutting off a selected length
of the advancing pipe assembly, thereby preventing the loss of
pressure within the pipe assembly being generated, permitting
uninterrupted advance of the pipe assembly and allowing positioning
of the air seal on the forward end of the advancing pipe
assembly.
20. A method according to claim 1, wherein the rate of linear
advancement of the pipe assembly is synchronized with the rate of
rotation of the pipe assembly, the rates of linear advancement and
of rotation being responsive to power from a single source.
21. A method for making plastic pipe comprising forming a conveyor
tube on a mandrel, the conveyor tube including at the exterior
thereof a layer of parting material and a stripping wire adjacent
said layer, winding a plurality of bands of resin impregnated fiber
elements onto the conveyor tube to provide a pipe assembly,
advancing the pipe assembly, and stripping the conveyor tube from
within the pipe assembly by pulling on the stripping wire.
22. A method according to claim 21, wherein forming the conveyor
tube on a mandrel comprises winding a plurality of strips on the
mandrel and adhesively uniting the layers provided by the strips,
winding a pair of strips including a strip of parting material in
staggered relationship onto the assembly of layers and
simultaneously winding a stripping wire between the staggered
strips to secure the stripping wire between the strips, the strip
of parting material being positioned on the exterior of the
conveyor tube.
23. A method according to claim 21, wherein the fiber elements in
each band are continuous and in parallel relationship wherein the
resin impregnant for the fiber elements is a thermosetting resin
composition; and wherein the resin impregnant is cured prior to
pulling on the stripping wire to remove the conveyor tube from
within the pipe assembly.
24. In a method for making fiber reinforced plastic pipe wherein a
resin composition and fiber reinforcement are applied about a
mandrel, the improvement which comprises providing a tube on the
mandrel which is nonadhesive thereto on the side adjacent the
mandrel, said tube having a separable adhesive coating on the
opposite side effective to adhere the tub to the resin composition
and to allow separation of the tube from the resin composition upon
treatment with a separating agent, the resin composition in its
polymerized state being unaffected by the separating agent,
applying a resin composition and fiber reinforcement around the
tube coated as aforesaid and polymerizing the resin composition to
form the pipe, treating the separable adhesive coating with a
separating agent, and removing the tube from within the pipe.
25. In a method according to claim 24 wherein the tube is of paper
and the separable adhesive is a water soluble composition.
26. In a method according to claim 25 wherein prior to applying the
resin composition and fiber reinforcement, water is applied to the
water soluble adhesive coating to moisten the coating and dampen
the paper, drying said coating, applying a heated resin composition
coating to the water soluble adhesive coating, and at least
partially polymerizing the resin composition.
27. In a method according to claim 25 including applying water to
the tube within the pipe to cause separation of the paper tube from
the pipe, and removing the paper tube from within the pipe.
28. In a method according to claim 26 including applying water to
the tube within the pipe to cause separation of the paper tube from
the pipe, and removing the paper tube from within the pipe.
29. In a method according to claim 25, wherein the tube comprises a
pair of paper tapes coated with the water soluble composition
helically wound upon the mandrel with their edges in overlapping
relation.
30. In a method according to claim 29 including applying water to
the tube within the pipe to cause separation of the paper tube from
the pipe, and removing the paper tube from within the pipe.
31. A method of forming plastic pipe comprising applying strips of
flexible release material longitudinally onto a mandrel in abutting
relationship, applying adhesive strips beneath the side margins of
the first-named abutting strips, whereby to form a release liner,
winding strip material impregnated with a thermosetting resin onto
the release liner, winding glass roving strands onto said strip
material, heating to polymerize said resin, and supporting the
release liner internally by inflating same with fluid under
pressure during the heating of the superimposed materials.
32. A method of forming plastic pipe according to claim 31, wherein
said fluid is allowed to escape at a restricted rate between the
mandrel and the release liner, whereby to provide a supporting
layer of fluid between the mandrel and the release liner.
33. A method of forming plastic pipe comprising applying strips of
flexible material longitudinally onto a mandrel in abutting
relationship, applying adhesive strips beneath the side margins of
the first-named abutting strips, whereby to form a release liner,
coating the release liner with a thermosetting resin, curing the
thermosetting resin with suitable heat to provide a cured resin
layer, winding a second strip material impregnated with a
polymerizable resin over the cured resin layer at a point where
said mandrel is reduced in diameter winding glass roving strands
onto said second resin impregnated strip material, thus putting the
cured resin layer in compression, heating the superimposed
materials to polymerize the resin of said second resin impregnated
strip, supporting the release liner internally by inflating same
with fluid under pressure during the heating of said superimosed
materials, and allowing fluid to escape at a restricted rate
between the mandrel and the release liner, whereby to provide a
supporting layer of fluid between the mandrel and the release
liner.
Description
The invention relates to improvements in methods and apparatus for
making substantially rigid, fiber reinforced plastic pipe.
A primary object of the invention is to provide a system for
automatically and continuously making fiber reinforced plastic pipe
under controlled conditions to thereby furnish pipe of uniform
thickness having a uniform amount of reinforcing material and resin
at all points around its circumference and throughout its
length.
Another object of the invention is to provide an automatic,
continuous system for fabricating fiber reinforced plastic pipe
wherein the means for continuously advancing the pipe being
generated through the system constitutes a fluid or air under
pressure.
A further object of the invention is to provide an automatic,
continuous system for fabricating pipe of the type under
consideration wherein a single source of power acts to rotate the
pipe assembly being fabricated and to operate various devices
serving to incorporate material into the pipe assembly as it is
generated and is combined with the air pressure means acting to
longitudinally advance the pipe assembly through the system.
Another object of the invention is to provide a method and
apparatus for the automatic and continuous manufacture of pipe
which includes providing a conveyor tube acting as a base for the
assembly thereon of the various elements which will constitute the
finished pipe, wherein the conveyor tube is constructed to include
means permitting the conveyor tube to be readily stripped from the
completed pipe assembly.
To realize the foregoing objectives with regard to an automatic and
continuous system for making pipe, a number of novel devices are
provided which, while they are particularly suitable parts of the
system, are also suitable for other applications or uses.
Accordingly, another object of the invention is to provide novel
means for controlling and synchronizing the linear advancement of a
cylindrical endless tube or pipe in relation to the rate of
rotation of the cylindrical body.
Still another object of the invention is to provide a novel means
for helically applying a band of parallel arranged continuous fiber
elements to an advancing hollow tubular member and to coat the
fiber elements as they are being applied.
Still a further object of the invention is to provide a belt system
of a novel construction which is adapted to enable the formation
thereon of a tube made essentially from a resinous composition.
Another object of the invention is to provide an improved device
for coating a continuously advancing strip or sheet.
Still another object of the invention is to provide plug means
insertable in a fluid or air filled pipe or the like which affords
suitable gripping of the pipe and a seal preventing the loss of
pressure within the pipe, the plug seal means being constructed so
that when it is unclamped from the pipe the fluid under pressure is
vented prior to the device releasing its grip on the pipe.
Still a further object of the invention is to provide an inflatable
sealing device arranged to grip the interior of a moving pipe
assembly for movement therewith, means being provided to return the
device to inactive position when deflated for reactivation and
movement with the pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
These, and other objects and advantages of the invention will be
apparent from the following description, taken in conjunction with
the drawings illustrating several preferred embodiments of the
invention, in which:
FIGS. 1, 1A and 1B together are a schematic showing of a continuous
system for making pipe in accordance with one embodiment of the
invention;
FIGS. 2-2E together represent a top plan view of apparatus for
making pipe in accordance with the embodiment of the invention
schematically illustrated in FIG. 1;
FIGS. 3-3E are a side elevational view of the apparatus shown in
FIGS. 2-2E;
FIGS. 4-4D taken together are a longitudinal cross-sectional view
of the mandrel and its associated parts;
FIG. 5 is an elevational view partly in cross-section looking in
the direction of the arrows 5--5 of FIG. 4A;
FIG. 6 is an elevational view partly in cross-section looking in
the direction of the arrows 6--6 of FIG. 4A;
FIG. 7 is a vertical cross-sectional view taken approximately in
the plane of line 7--7 of FIG. 4A;
FIG. 8 is a vertical cross-sectional view taken approximately in
the plane of line 8--8 of FIG. 4B;
FIG. 9 is a vertical cross-sectional view taken approximately in
the plane of line 9--9 of FIG. 4B;
FIG. 10 is a front elevational view of means for coating a strip to
be wound upon the mandrel to provide a conveyor tube component of a
pipe assembly which in one embodiment of the invention becomes an
integral part of the finished product;
FIG. 11 is a side elevational view looking toward the right side of
the device shown in FIG. 10;
FIG. 11A is a partial plan view showing the manner in which a resin
composition is applied to a carrier strip by the device shown in
FIGS. 10 and 11;
FIG. 11B is a side elevational view of the elements shown in FIG.
11A;
FIG. 12 is a side elevational view of means for guiding and
impregnating continuous fiber elements for application to the
conveyor tube in substantially circumferential windings;
FIG. 13 is a front elevational view of the device shown in FIG. 12,
this view also showing the manner in which the partially fabricated
pipe assembly is supported at this station in the apparatus;
FIG. 14 is a front elevational view of a winding head;
FIG. 15 is a side elevational view, partly in section, looking in
the direction of the arrows 15--15 of FIG. 14;
FIG. 16 is an enlarged, partial side elevational view showing the
means on a winding head for guiding the continuous fiber elements
onto the pipe assembly being generated;
FIG. 17 is a section taken approximately in the plane of line
17--17 of FIG. 14;
FIG. 18 is a longitudinal cross-sectional view of the plug used to
seal the forward end of the moving pipe assembly;
FIG. 19 is a view similar to FIG. 18, this view showing the seal
plug in its released condition;
FIG. 20 is a vertical cross-sectional view taken approximately in
the plane of line 20--20 of FIG. 18;
FIG. 21 is an end elevational view, partly in cross-section,
looking in the direction of the arrows 21--21 of FIG. 18;
FIG. 22 is a side elevational view of the means for controlling the
advancement of the pipe assembly through the apparatus;
FIG. 23 is a vertical cross-sectional view taken approximately in
the plane of line 23--23 of FIG. 22;
FIG. 24 is a vertical cross-sectional view taken approximately in
the plane of line 24--24 of FIG. 22;
FIG. 25 is a front elevational view of the device shown in FIG.
22;
FIG. 26 is a vertical cross-sectional view taken approximately in
the plane of line 26--26 of FIG. 25;
FIG. 26A is a diagrammatic showing of means for sensing axial
thrust which may be imposed upon the means for controlling the
advancement of the pipe assembly;
FIG. 27 is a longitudinal cross-sectional view, partly in
elevation, showing inflatable means cooperative with the fabricated
pipe assembly to prevent the loss of fluid or air pressure within
the pipe assembly when a section of the continuously fabricated
pipe assembly is cut off;
FIG. 28 is a view similar to FIG. 27, except that a fluid seal plug
is shown positioned in the forward end of the continuously
fabricated pipe assembly, whereupon the inflatable fluid sealing
means cooperative with the pipe as shown in FIG. 27 is not
exercising its function;
FIG. 29 is a vertical cross-sectional view taken approximately in
the plane of line 29--29 of FIG. 27;
FIG. 30 is a vertical cross-sectional view taken approximately in
the plane of line 30--30 of FIG. 27;
FIG. 31 is a vertical cross-sectional view taken approximately in
the plane of line 31--31 of FIG. 27;
FIG. 32 is an enlarged longitudinal cross-sectional view showing
the inflatable means cooperative with the pipe assembly when such
means is acting to prevent the loss of pressure within the pipe
assembly;
FIG. 33 is a longitudinal cross-sectional view showing the
relationship of spring means used in conjunction with the
inflatable seal means which allows the movement of the inflatable
seal means with the advancing pipe assembly;
FIG. 34 is an enlarged longitudinal cross-sectional view showing
the manner in which the spring means is anchored to the inflatable
seal means;
FIG. 35 is a breakaway showing of pipe which may be made with the
apparatus shown in FIGS. 1-34;
FIG. 35A is an enlarged section taken in the plane of line 35A--35A
of FIG. 35;
FIG. 36 is a schematic showing of means for forming a conveyor tube
which is removable from the completed pipe assembly;
FIG. 37 is a top plan view of that portion of the apparatus for
making a conveyor tube portion which is removable from the pipe
assembly;
FIG. 38 is a side elevational view of the apparatus shown in FIG.
37;
FIGS. 39 and 39A together are a side elevational view, partly
broken away and in section, showing the relationship of the means
for applying several of the components of the removable conveyor
tube to the mandrel;
FIG. 40 is an elevational view partly in cross-section looking in
the direction of the arrows 40--40 of FIG. 39;
FIG. 41 is an elevational view partly in cross-section looking in
the direction of the arrows 41--41 of FIG. 39;
FIG. 42 is a breakaway showing of a pipe assembly made in
accordance with the embodiment of the invention schematically
illustrated by FIGS. 36, 1A and 1B taken together, and structurally
shown in FIGS. 37, 38, 2A-2E and 3A-3E taken together;
FIG. 42A is a vertical section taken in the plane of line 42A--42A
of FIG. 42;
FIG. 43 is a side elevation taken in partial cross section of
another embodiment of the invention for providing an air seal
within the generated pipe and of another embodiment of the
invention for forming a conveyor tube on the mandrel;
FIG. 44 is a cross-sectional view taken as indicated by the lines
and arrows 44--44 of FIG. 43;
FIG. 45 is a cross-sectional view taken as indicated by the lines
and arrows 45--45 of FIG. 43;
FIG. 46 is a cross-sectional illustration with parts broken away
schematically illustrating another embodiment of the invention for
forming continuous glass-reinforced plastic pipe; and
FIG. 47 is an enlarged cross-sectional view taken through the
formed pipe and mandrel structure of FIG. 46.
SUMMARY OF THE INVENTION
In accordance with the invention generally, substantially rigid,
fiber reinforced plastic pipe is made automatically and
continuously with a minimum of power requirements considering the
mass of the materials (glass, resin, etc.) being processed and
conveyed through the line. This is accomplished by utilizing a
fluid or air under pressure to furnish an axially or longitudinally
directed thrust to linearly advance the pipe assembly being
fabricated. Such manner of using air pressure furnishes a component
of force in a radial or circumferential direction with respect to
the pipe assembly being advanced by such application of pressure,
which assists in the various operations wherein materials are being
drawn off and circumferentially wound into the pipe assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 1A and 1B, the method of the invention
generally comprises providing an air impervious tube T on an
axially fixed, hollow, rotatable mandrel which is generally
designated A. The mandrel is provided on the exterior thereof with
means B to furnish an air seal with the interior of the conveyor
tube as the conveyor tube is advanced over the mandrel. A plurality
of bands a and b of resin impregnated continuous fiber elements are
wound onto the conveyor tube T to provide a pipe assembly P (FIGS.
35 and 35A). The pipe assembly is rotated as the pipe assembly is
continuously advanced through the apparatus. Air under pressure is
directed through the mandrel and out from the forward end 50
thereof into the interior of the pipe assembly as the assembly is
being generated. The forward end of the pipe assembly is closed off
by an end closure or plug seal means C so that the pipe assembly,
together with the seal portion B of the mandrel and the plug seal
means, provide a sealed chamber. The air under pressure within the
sealed chamber imparts an axially directed thrust to advance the
pipe assembly. In effect, the sealed chamber is expanded axially or
longitudinally as the air under pressure acts to impart forward
movement to the processed pipe. To synchronize and control the
various operations involved in fabricating the pipe assembly, means
D is provided for controlling the rate of linear advancement of the
pipe assembly.
In greater detail, FIGS. 2-2E and FIGS. 3-3E illustrate the
apparatus for the continuous manufacture of pipe in accordance with
one preferred embodiment of the invention. The apparatus is
provided with a frame structure comprising transversely spaced,
longitudinally extending lower support members 52 and a central,
longitudinally extending upper support member 54 secured together
by frame members 56 in any suitable manner as by bolting or
welding. The frame structure provides means for supporting one end
of the mandrel A.
The mandrel A comprises means for furnishing a number of purposes
and functions as will subsequently appear, and includes a
cylindrical, hollow tube 57 which is fixed against axial movement
and mounted for rotation. This tube portion of the mandrel provides
the means for conveying air under pressure to linearly advance the
pipe assembly as it is fabricated and to support a plurality of
means for the processing of several elements incorporated in the
pipe assembly. The tube 57 is of a structurally rigid material such
as stainless steel. At the beginning of the line, means is provided
for journaling one end of the tube and to provide means for
directing fluid or air under pressure axially through its interior
and out from the forward or opposite end 50.
Referring to FIG. 4, a stationary coupling member 58 is provided
and held to prevent its rotation in any suitable manner. The rear
end of the tube 57 is rotatably supported within the interior or
central bore 60 of the stationary coupling member for a portion of
the member's length. Also positioned within the bore 60 is a rotary
coupling 62 having a portion 64 of reduced diameter which is
received within the interior of the tube 57 with a close fit. The
tube and the rotary coupling are connected to one another for
rotation together by a roll pin 66. The portion 68 of the rotary
coupling having a larger diameter is of a diameter slightly less
than the diameter of the bore 60 of the stationary member. O-rings
70 and 72 provide fluid or air sealing means between the rotary
coupling and the associated stationary coupling member, and between
the tube and the stationary coupling member. The rotary coupling 62
is held within the stationary coupling member 58 by a bolt 74 and a
washer 76 at one end and at the other end by a collar 78 which is
secured to tube 57 by a cap screw 80. By the described arrangement,
the tube 57 and the rotary coupling connected thereto are mounted
for rotation together. Axial longitudinal movement of the tube 57
is prevented by a collar 73 secured to the tube by a setscrew 75,
the collar abutting a pillow block 77 bolted to a plate 79 which is
fixed to the standard 56.
As also shown in FIG. 4, means is provided for directing air under
pressure axially through the interior of the tube 57 so that the
air may be confined and pass through the tube and out from the
forward end 50 of the mandrel, which opens into the pipe assembly
as the assembly is being fabricated. The stationary coupling member
58 is provided with a threaded opening 82 extending through the
wall thereof within which there is screwed a fitting 84 connected
to a suitable source of compressed air (not shown). In order that
the compressed air may have access to the interior of the hollow
tube, the stationary coupling member is provided with a section 86
of increased inner diameter adjacent the opening 82 and adjacent
the outer wall of the mandrel. Also, the wall of the tube is
provided with a series of circumferentially spaced orifices 88
adjacent the section 86 to place the interior of the mandrel in
communication with the line to the source of compressed air.
As also shown in FIG. 4, a second line for conveying air under
pressure is provided. The stationary coupling member 58 is provided
with a second opening 90 extending through the wall thereof to
receive a second fitting 92 connected to a source of compressed air
(not shown). The rotary coupling 62 is provided with a
diametrically extending channel 94 to place the central bore 96 of
the rotary coupling in communication with the second air line. A
second tube 98 of substantially smaller diameter than the inner
diameter of the tube 57 extends throughout the length thereof and
beyond to convey the air under pressure from the second source to
inflatable means E (FIG. 1B and FIGS. 21-28) having the purpose and
function to be subsequently described. One end of the tube 98 is
force-fitted or otherwise secured within the bore of a hollow
connecting member 100, the opposite end of the connecting member
being suitably secured within the bore 96 of the rotary coupling
62. As shown, such connection may be accomplished by providing
mating tapered portions on the rotary coupling head and on the tube
connecting member and force-fitting the parts. By the described
arrangement, the air line or tube 98 is connected for rotation with
the rotary coupling and with the tube 57 through which it
extends.
In the embodiment of the invention illustrated in FIGS. 1, 1A and
1B, and FIGS. 2-3E, the air impervious conveyor tube T is a resin
liner which becomes an integrated part of the completed pipe
assembly. Accordingly, the mandrel A is provided with means
permitting the formation of a tubular resin liner while allowing
this form of conveyor tube to be rotated and advanced with respect
to the mandrel without adhering to the mandrel. Such means,
designated F, is illustrated schematically in FIG. 1 and
structurally in FIGS. 4A, 4B, 4C, 4D and FIGS. 5-9.
Essentially, the means F comprises a system of flexible, endless
belts made of or comprising a flexible material coated with a mold
release material. Examples of suitable mold release materials or
materials to which a wet, sticky resin composition will not adhere
are a tetrafluoroethylene polymer (Teflon), polypropylene, or the
like. The belts, which are not powered, are arranged to rotate with
the mandrel and to travel longitudinally with their longitudinal
edges slightly overlapping to, in effect, provide a continuous,
longitudinally movable tube. Whatever longitudinal movement is
imparted to the belts is caused by the linear advancement which is
imparted to the pipe assembly P of which the conveyor tube is a
part.
As shown in FIGS. 4A, 4B, and 5-8, the mandrel A includes a belt
support sleeve 102 over which a plurality of belts may travel
longitudinally to furnish a movable tube of non-adherent material.
The belts which will be referred to as the outer belts 104 and
inner belts 106, have their longitudinal edges slightly overlapped
as they travel over the sleeve 102 as shown in FIG. 7. The diameter
of the belt support sleeve 102 is selected to furnish, with the
added thickness of the belts, the inner diameter desired for the
completed pipe. The belt support sleeve is connected to the tube 57
by a spider supporting member 108. The spider form of support means
used here and elsewhere in connection with the belt system
furnishes the desired supporting function while allowing the belts
to extend and run through such form of support. The spider 108 is
supported on its inner diameter by a sleeve 107 secured to the tube
57 by a set screw 109 (FIG. 4A).
As shown in FIGS. 4A, 4B, and 5, the plurality of outer belts 104,
here shown to be three in number, is supported so that at one end
they pass around respective spaced rollers 110. The rollers are
supported upon a spider assembly 112 having circumferentially
spaced support arms 114 upon which the respective rollers 110 are
mounted for rotation on pins 116. The spider assembly 112 is
fastened to a sleeve 118 as by welding, the sleeve closely
surrounding the tube 57. The sleeve and associated mounting for the
rollers 110 may be adjusted along the length of the tube to the
desired position and secured in place by a set screw 120 (FIG.
4A).
As shown in FIGS. 4A, 4B and 5, a similar arrangement is provided
for the mounting of the inner belts 106 at one of their ends. As
illustrated, the inner belts are also three in number. Rollers 122
which respectively support the inner belts are located however on a
smaller diameter than the diameter prescribed by the outer belt
rollers 110. The inner belt rollers 122 are mounted upon a spider
assembly 124 having circumferentially spaced support arms 126 upon
which the respective rollers 122 are mounted for rotation on pins
128. Similarly, the spider assembly 124 is fastened to a sleeve 130
as by welding. The sleeve which closely surrounds the tube 57 is
adjustable along the length of the tube to the desired position,
and is secured in place by a set screw 132 to locate the rollers
122 in desired position lengthwise of the mandrel.
As shown in FIGS. 4A and 6, guide means may be provided for the
intermediate reaches of the belts, and this may be accomplished by
providing a guide member 134 which, like the supporting means for
the outer and inner rollers, is located rearward of the belt
support sleeve 102. The guide member 134 is provided with
circumferentially spaced slots 136, there being three to
accommodate the three outer belts. Pairs of slots 138, 138' allow
the inner belts to run therethrough and are thereby guided. The
guide member 134 is maintained in fixed relationship with respect
to the tube 57 by suspending it from an arm 140 extending
longitudinally from the spider support 124 for the inner belt
rollers. The connection between the arm 140 and the radially
extending support 124 may be made by a screw connection 142.
The opposite ends of the outer and inner belts 104 and 106 run
about guide means provided by a belt return guide assembly 143
supported upon tube 57 and located down the line from the belt
support sleeve 102. As shown in FIG. 4B, the largest diameter of
the guide assembly 143 does not exceed the diameter of the belt
support sleeve 102 so that the conveyor tube form of resin liner
which will be formed on the belts may rotate and advance through
the equipment without interference.
As shown in FIGS. 4B and 8, the belt return guide assembly 143
includes an annular outer belt return guide member 144 provided
with spaced slots 146 to allow passage around the smoothly rounded
portions 148 and the return of the outer belts 104. The guide
assembly is also provided with an annular belt return guide member
150 having spaced slots 152 for the support and return of the inner
belts 106. The guide member 150 also is provided with slots 153 for
guiding the outer belts which have a longer reach than the inner
belts. The annular return guide members 144 and 150 surround the
tube 57 but are not fastened thereto. The return guide assembly
143, of which the guide members 144 and 150 are parts, is rotatable
with respect to the tube 57 to prevent torque build-up in the belt
system. Accordingly, the guide members 144 and 150 are connected to
each other and to a bearing sleeve 154 which closely surrounds the
tube 57 but is rotatable with respect thereto. A plurality of
longitudinally extending, circumferentially spaced fork members 156
are connected to and extend rearwardly from a bearing sleeve 154 to
connect the guide members 144 and 150 to one another and to the
bearing sleeve. The parts are connected to one another in any
suitable manner as by welding. The fork members possess the
additional function of providing guide means for the outer belts,
and if desired, a fork member 158 may be paired with each fork
member 156 for the guiding function. The second fork member of a
pair need not extend to the guide member 150 for connection
thereto, sufficient structural strength being provided by the
several fork members 156 which bridge the guide members and the
bearing sleeve.
As also shown in FIG. 4B, the bearing sleeve 154, though rotatable
with respect to the tube portion 57 of the mandrel, is mounted on
the tube in a manner to limit its movement in a longitudinal
direction. For this purpose, a collar 160 is positioned on the tube
57 and set in the desired position by means of a set screw 62. A
washer 164 is positioned intermediate the bearing sleeve and the
collar. Thus, the collar and the guide assembly 143 cannot move
rearwardly on the tube and impart undesirable slack to the belt
system after the collar has been properly positioned on the
tube.
As will be evident from FIGS. 4A and 4B, the outer and inner belts
104 and 106, after passing over the support sleeve 102, return
through its interior. To further assist in guiding the belts, a
guide ring 166 is positioned intermediate the support sleeve and
the tube 57. Both the outer and inner belts run over the outer
periphery of the guide ring which is held between collars 168,
168'. The collars are provided with respective set screws 170, 170'
so that the guide ring may be located in desired position along the
length of tube 57.
In order that the resin liner form of conveyor tube T formed on the
sleeve supported flexible belts may be suitably supported and
engaged by the aforementioned seal means B, the mandrel A includes
a second sleeve 172 down the line from the belt support sleeve 102.
As shown in FIGS. 4B and 4C, the sleeve 172 having a diameter to
allow slight clearance with respect to the conveyor tube which will
advance over it surrounds the tube 57. Although the tube 57 may be
continued through the sleeve 172, for convenience of assembly the
sleeve 172 is provided with an inner support ring 174 which may be
connected to the sleeve 172 as by countersunk screws 176. The inner
diameter of the support ring is connected to a coupling sleeve 178
fixed to the tube 57 by a set screw 179. A tube 57' constituting a
continuation of tube 57 is screw threaded to the coupling sleeve
178. The support ring 174 is formed with spaced apertures 181 to
allow any air which may escape rearwardly of the seal at B to be
vented (FIGS. 4B and 9). As will be subsequently described, the
inner seal means B provided by the mandrel is supported by and
connected to the tube 57' and the sleeve 172.
To supply the resin c (FIGS. 35 and 35A) which will furnish the air
impervious conveyor tube T and constitute an integrated part of the
finished pipe assembly, means G is provided as shown in FIGS. 2 and
3, and in greater detail in FIGS. 10, 11, 11A and 11B. It is
preferred to use thermosetting resin compositions; for example, an
epoxy resin composition with a suitable hardener or curing agent,
polyester resins, or the like. While the resin composition may be
applied directly in liquid form to the described belt system, it is
preferred that the resin composition be applied on a carrier strip
d which is helically wound onto the belts. Two coating devices G
are shown. It is within the scope of the invention to use but one
device. Two devices are used where it is desired to obtain a resin
liner of substantial thickness. The devices G are identical and the
description which follows of one such device is equally applicable
to the other.
The resin c is applied to a highly absorbent and porous strip of
material d. The strip material is preferably 12 pound tissue paper
having a width of approximately 1 inch. As shown in FIGS. 10 and
11, the absorbent tape or strip d is withdrawn from a roll 180, led
around a guide pin 182 and around a guide roll 184 provided with
suitable means for adjusting tension as is known in the art. The
strip then runs horizontally over a guide pin 186 immediately
rearward of an endless doctor blade 188 which is mounted for
continuous movement transversely of or over and across the path of
the horizontally moving strip d. The doctor blade, which is in the
form of a thin continuous band of steel, is mounted to pass around
a pair of longitudinally spaced grooved wheels 190, 190'. To power
the movement of the doctor blade band, one of the wheels, the wheel
190, has fixed to the rear thereof a gear 192 which is rotated by a
gear 193 secured to the shaft of a fractional horsepower motor 194
connected to a suitable source of current (not shown). The gear
ratios are selected to rotate the wheel 190 and thereby the doctor
blade band 188 around such wheel and the opposite idler wheel at a
desired regulated and constant speed.
As also shown in FIGS. 10 and 11, the doctor blade band wheels 190,
190' and the doctor blade band 188 are supported in a manner to
enable the adjustment of the angle of the band with respect to the
strip to be coated. Also, means is provided for the adjustment of
tension upon the doctor blade band.
The band support wheels 190, 190' are mounted for rotation on
bearings within the respective wheels on shafts extending into
support plate 196. The support plate is secured within a U-shaped
frame 197 of a thickness sufficient to allow pivot pins to be
extended into its sides. The plate and frame assembly is pivotally
connected at each side by threaded pivot pins 198, 198' to
longitudinally spaced brackets 200, 200' which are fixed, as by
welding, to a cross frame member 202 secured to extend between and
to one side of a pair of longitudinally spaced frame standards 204,
204'. As shown in FIG. 10, the support plate 196 and its associated
frame 197 is generally U-shaped to allow passage of the continuous
strip or tape d over the base portion and between the arm portions
of the assembly. The support plate and its frame are tiltable about
the pivot pins 198, 198' to enable adjustment of the angle of the
band 188 with respect to the plane of the strip d as it is drawn
off the roll 180 under controlled tension and guided by the
aforementioned guide pins. Then, the support member is releasably
secured in position as by wing nuts associated with the pivot pins.
In this manner, the amount of resin applied to the strip may be
adjusted at the nip between the travelling doctor blade and the
moving strip (FIG. 11B) for predetermined rates of movement of the
doctor band and of the strip. Means including a screw 206 is
provided for adjusting the tension upon the doctor blade band, such
adjustment screw being associated with the bearing for one of the
doctor band wheels which is mounted in a manner to permit the axis
of rotation of doctor band wheel 190' to be moved toward or away
from the axis of rotation of the other doctor band wheel.
The liquid resinous material of a suitable viscosity is applied to
the moving strip d in any desired manner. It is preferred, however,
and as shown in FIGS. 10-11B, to meter the resin composition onto
the strip from an applicator mixer 208 which, when an epoxy resin
composition is used, mixes and meters a controlled amount of resin
and hardener in desired proportions onto the strip. The mixer
applicator or dispenser is operated by a fractional horsepower
motor connected to a suitable source of current (not shown). The
liquid resinous composition is applied to the strip in the form of
a stripe 210, as shown in FIG. 11A. As shown in FIG. 11, the mixer
applicator is supported upon a bracket 212 terminating in a hub 214
mounted for vertical adjustment upon the guide rod 216 to thereby
permit adjustment of the mixer applicator with respect to the strip
d. When the strip moves under the band form of doctor blade 188,
the resin composition is spread across the width of the strip for a
predetermined thickness determined by the angle of the doctor blade
band, the rates of movement of the doctor blade band and the strip,
and the selected rate of deposition upon the strip of the liquid
resin composition by the mixer applicator. To assure that the
doctor blade band is maintained in a clean condition after having
served to spread the liquid resin composition across the width of
the moving strip, a heater 218 positioned to surround the doctor
blade band is mounted upon a bracket 220 fastened to the support
member 196, as shown in FIG. 10. Preferably, an electric coil type
of heater is used connected to a suitable source of current (not
shown), the heater acting to burn off any resinous material which
may adhere to the smooth surface of the doctor blade band.
In order that the device G shall not require that its operation be
stopped when a roll of strip material is exhausted, a second or
ready roll 222 is provided to replace the exhausted roll 180. As
also shown in FIGS. 10 and 11, one roll, the roll 180, is mounted
upon a spindle 224 connected to the top end of a rocker arm 226
pivotally connected at its lower end to a shaft 228 extending
between the spaced standards 204, 204'. The spindle is provided
with the usual spaced plates to confine a roll of the strip
material or tape between them. An arcuate member 230 is secured at
one end to the rocker arm 226, the arcuate member being provided
with a series of spaced apertures 232. A pin 234 is extended
through the adjacent standard and through a selected aperture 232
in the arcuate member 230 to thereby furnish adjustability to the
desired angular position for a roll of strip material. A similar
arrangement is provided for the second roll 222 which is mounted
for adjustment to desired position on like numbered parts with
respect to the opposite standard. As will be evident from FIG. 10,
when a roll of strip material or tape is about to be exhausted, the
depleted roll may be pivoted around behind the ready roll which is
moved into feeding position after splicing. Then, a new roll of
strip material is placed in the ready position.
Where, as preferred, an epoxy resin composition is used to furnish
the resin for a liner form of conveyor tube T, the same means for
rotating the pipe assembly of which the conveyor tube T is a part
may be used to synchronously pump desired amounts of resin and of
hardener in regulated proportions to the mixer 208. For this
purpose, means H is associated with a coating device G. Where two
coating devices are used, there is one resin and hardener supply
means for each coating device.
As shown in FIGS. 2, 2A, 3 and 3A, a tank 238 is compartmentized to
contain an epoxy resin composition in one compartment 240 and a
hardener composition in the other compartment 242. As shown, the
tank is supported on legs 244 so that the tank may be located
adjacent one of the longitudinally extending base frame members 52.
A pump 246 is provided to convey resin from the compartment 240 to
the mixer applicator 208 through a hose 248 and a second pump 250
delivers the hardener composition to the mixer through a hose 252.
A hose 254 extends between the resin pump 246 and the resin
compartment and another hose 256 extends between the hardener
compartment and its associated pump 250.
Preferably, the pumps 246 and 250 are operated by the same motor
which operates the winding heads designated I (FIGS. 2B, 2C, 3B and
3C), which are located forward in the line to helically wind bands
of fiber elements b into the pipe assembly P. The single motor for
operating the pumps, the winding head I, also the aforementioned
means D for controlling the rate of linear movement of the pipe
assembly, is shown in FIGS. 2D and 3D and is designated 258. For
example, when making two inch diameter pipe, and in conjunction
with air pressure as herein applied, the motor may be only
approximately 1/2 H.P. Air pressure in the main air line provided
by the tube 57 and its extensions is approximately 40 p.s.i. For 3,
4 and 6 inch diameter pipe, the horsepower of the motor and the air
pressure are of course increased.
As shown in FIGS. 2D and 3D, the shaft of the motor 258 is provided
with a pulley 260 about which passes a belt 262 cooperable with a
pulley 264 fixed to a driving shaft 266. The motor is supported
upon a bracket 268 secured to a frame member 56'. The driving shaft
extends forwardly of the machine for cooperation with the linear
advance control means D (FIGS. 2E and 3E). The driving shaft, which
is journaled to extend through longitudinally spaced pillow blocks
267 secured to the longitudinally extending upper frame member 54
also extends rearwardly to the winding heads I, and through
intermediate coupling means the driving shaft acts to drive a shaft
268 which operates the aforementioned pumps 246 and 250.
As shown in FIGS. 2B and 3B, the driving shaft 266 extends along
the top of the machine and the driven shaft 268 extends along the
base of the machine where the latter shaft is journaled to extend
through longitudinally spaced pillow blocks 270 secured to the base
frame member 52. This transfer of power from the driving shaft to
the driven shaft is accomplished by a series of pulleys and belts.
The end of the driving shaft 266 is provided with a pulley
cooperable with a pulley on one end of a stub shaft 272, the two
pulleys receiving a belt 274. The opposite end of the stub staff is
also provided with a pulley over which runs a belt 276, the belt
running over a second pulley 278 on an end of a stub shaft 280
located below the stub shaft 272. The stub shaft 280 is located
near the base of the machine whereas the stub shaft 272 is suitably
mounted near the top of the machine. The opposite end of the stub
shaft 280 is also provided with a pulley 282 cooperable with a
pulley 284 on the end of the driven shaft 268, these latter two
pulleys receiving a belt 286.
As shown in FIGS. 2, 2A, 3 and 3A, the driven shaft 268 is provided
with a pulley 288 adjacent each device H. A belt 290 extends around
the pulley and around a second pulley 292 keyed to the shaft of a
speed control device 294. A shaft on the opposite side of the
control device has a pulley 296 keyed thereto to operate a gear
reducer 298, such gear reducer providing a shaft having a pulley
300 fixed thereto. A belt 302 extends around the pulleys 296 and
300 to actuate the gear reducer. The shaft extending through the
opposite side of the gear reducer is provided with a centrally
positioned gear 304 cooperating with a gear 306 for the resin pump
246, and on its opposite side with a gear 308 for the hardener
composition pump 250. Thus, the motor 258 through the described
drive arrangement serves to deliver resin and hardener to the mixer
applicator 208 off the same driving means which actuates a number
of other operations in synchronism throughout the line.
The resin c carried by the absorbent strip or strips d in helically
wound onto the tubular arranged belts 104, 106 supported on the
sleeve 102. The power to withdraw the strip from its roll and past
the doctor blade 188 is furnished by the rotation imparted to the
pipe assembly P and conveyor tube portion T thereof by the driven
winding heads I up the line. Between the coating device O and the
belt system provided by the mandrel, heating means 310 is provided
adjacent the path of the resin composition coated strip d to cause
the resin composition to pass through the porous strip material to
the underside thereof, whereby the resin composition is situated on
both sides of the strip. The heater 310 is shown in FIG. 2 and the
resultant relationship of the resin c on each of the strips d is
shown in FIG. 35A.
After the strip d carrying the resin c is helically wound onto the
tubular arranged, adhesion resistant belts 104, 106 to form a
conveyor tube essentially of resin, heat is applied to partially
cure to a substantial extent the resin composition. As shown in
FIGS. 2 and 3, a heater or series of heaters 312 are suspended from
the central upper frame member 54 by suitable straps 314. The resin
liner form of conveyor tube T, after having advanced beyond the
reach of the belts, passes through a cooling device 316 and now
constitutes an air impervious tube having a substantial measure of
rigidity. The tubular resin liner is rotated and advanced in the
machine over the aforementioned sleeve 172 where the inner surface
of the resin conveyor tube is engaged by the seal means B as shown
in FIG. 4C.
The fluid seal means B prevents air under pressure which is
conveyed out of the end of the mandrel at 50 (FIGS. 1, 1A and 4D)
from passing rearwardly of the seal means. Such seal means provides
one end of a closed chamber within the pipe assembly P as the pipe
assembly is generated by the apparatus, the opposite end of the
closed chamber being supplied by the aforementioned plug means C
which is inserted in the forward end of the advancing pipe
assembly.
As shown in FIG. 4C, the seal means B is in the form of a tapered,
open-ended cup-like member 318 having an annular bead 320 at its
forward end, the bead being of a diameter to closely engage the
inner surface of the conveyor tube T which advances thereover and
rotates with respect therewith. A material suitable for furnishing
the desired characteristics of providing a seal when engaged with
the interior of a conveyor tube while allowing sliding and rotating
motion of the conveyor tube with respect to the bead portion is
rubber or a rubber-like material such as silicone rubber. As
illustrated, the seal member 318 is held in position by the
clamping action thereupon of a tapered outer clamping sleeve 322
and an inner clamping sleeve 324. The clamping sleeve 322 is
preferably made of a tetrafluoroethylene polymer (Teflon). The
inner clamping sleeve is internally threaded at 326 and matingly
threaded around the outer diameter of a portion 328 of reduced
diameter provided by a coupling member 330. The coupling member has
a portion 332 which is received between the sleeve 172 and the air
conveying tube 57'. The member 330 is made flush at its exterior
with the outer surface of the sleeve 172 so that the sleeve 172,
the coupling member 330 and the outer clamping sleeve 322 provide a
smooth, continuous surface. The portion 332 of the coupling member
330 is formed to provide a shoulder 334 against which is seated an
internal flange 336 of the outer clamping sleeve 322. The seal
member 318 also has an internal flange 338 which is clamped between
the flange 336 and the end of the internal clamping sleeve 324 when
the latter clamping member is threaded onto the inner tubular
portion 328 of the coupling member. The tubular portion 328
constitutes an extension of the air conveyor tube 57, 57'. The
taper on the upper clamping sleeve 322 and the uniform thickness of
the seal member 318 rearward of the bead 320 furnishes a firm but
resilient mounting for the seal member's bead portion 320.
As shown in FIG. 4D, a set screw 340 is extended through the
interior clamping sleeve 324 and into the tubular portion 328 of
the coupling member to thereby prevent the clamping of the seal 318
from being loosened from its clamped position. As also shown in
FIG. 4D, a longitudinally extending sleeve 342 is secured to the
outer surface of the tubular portion 324 as by welding. The
diameter of the sleeve 342 is less than the inner diameter of the
conveyor tube whereby air under pressure passing through the tube
57 and its extensions 57', 328 and 342 may pass out of the end 50
and provide an air support intermediate the pipe assembly being
generated and the portion of the mandrel forward of the annular
bead 320 of the seal means.
As schematically shown in FIG. 1A after the conveyor tube has been
provided on the mandrel, and preferably before the conveyor tube
has passed beyond and over the seal means B, the tube is overwound
with a layer a (FIG. 35) of parallel arranged continuous fiber
elements guided and impregnated with a resin composition by a
device generally designated J. While the continuous elements may be
of any suitable fiber, it is preferred to use rovings of glass. At
the station where the first device J is located, the band of
parallel arranged fiber elements is preferably applied with the
fiber elements at an angle of approximately 82.degree. to the
longitudinal axis of the pipe and, as indicated in FIG. 35, there
are four such layers of windings a, a1, a2 and a3 in the finished
pipe alternated with three layers b1, b2 and b3 of fiber elements
laid down at a relatively low angle of approximately 16.degree. and
of opposite hand. It will be understood, however, that the number
of layers, the angles at which the fiber elements are laid into the
pipe assembly, the amounts of fibrous material in the respective
layers, and the amount of resin impregnant are a matter of choice
depending upon the circumferential-axial strength ratio desired to
provide a balanced pipe structure. The number of winding heads and
devices for impregnating the fiber elements and applying layers of
fiber elements wound at a relatively high angle used in the line
depends upon the number of layers and the amounts of fiber and
resin desired in the finished pipe.
Referring to FIGS. 12 and 13, the fiber element guiding and
impregnating device 11 comprises a suitably supported tank or bath
344 containing a suitable liquid resin composition. A wheel
supporting frame comprising a pair of transversely spaced,
vertically extending frame members 346, 346' is spaced rearwardly
of a guide frame member 343. An angled structural member 348
extends between the two spaced frame supporting means. The wheel
frame structure also includes the converging structural members
350, 350' extending from the upper ends of transversely spaced
frame members 346, 346' to provide an arch arrangement, as shown in
FIG. 13.
In applying the first layer a of substantially circumferentially
applied windings to the conveyor tube T, it is not necessary to
preliminarily coat the conveyor tube. Accordingly, the first
guiding and impregnating device J in the line may be located to the
side of the line, as shown in FIGS. 2B and 3B, and the wheel
supporting frame and the relationship of the wheels about to be
described may be omitted at this station. However, a device J1 will
be described to include the arrangement of wheels because the wheel
arrangement has an important function when the devices J1, J2, and
J3 are located immediately forward of and related to the winding
heads I1, I2 and I3, respectively. As shown in FIGS. 2B and 2C, the
paired devices I1-J1, I2-J2 and I3-J3 are located centrally in the
line beneath and surrounding the advancing conveyor tube T having
the layer a thereon.
Where for the application of the first layer a of windings to the
conveyor tube T, a J1 form of device is located centrally and
immediately adjacent the conveyor tube being generated, the
conveyor tube is supported and preliminarily coated with a resinous
composition from the same bath which impregnates the fiber elements
wound as the layer a onto the conveyor tube. As shown in FIGS. 12
and 13, a coating wheel 352 is suspended from the frame member 350'
by an adjustably mounted bracket 354 providing an axis of rotation
356 for the wheel. The bracket is slotted to allow its adjustment
with respect to the frame structure by screws 358 extending through
slots in the bracket and into threaded openings in the frame member
350'. The coating wheel 352 has a portion thereof submerged within
the bath 344. A support wheel 360 is journaled for rotation on a
bracket 362 connected to the frame member 350 in a manner to also
allow adjustment of the position of this wheel. As shown, the
wheels are arranged so that the conveyor tube T is supported by the
two wheels. Rotation imparted to the pipe assembly and its conveyor
tube portion causes the wheels, which are not otherwise powered, to
rotate whereupon the coating wheel 352 applies a resin coating to
the conveyor tube. To confine the conveyor tube upon the coating
and supporting wheels, a guiding wheel 364 is suspended from the
frame structure to engage the rotating and advancing conveyor tube
at a third point or above the areas where the tube is engaged by
the wheels 352 and 360. Similarly, the wheels 364 is suspended from
a bracket 366 adjustably connected to the frame structure.
As also shown in FIGS. 12 and 13, immediately adjacent the
described wheel arrangement and forward thereof, means is provided
for guiding and impregnating the fiber elements which are wound
substantially circumferentially onto the conveyor tube. The
continuous fiber elements which furnish the layers a, a1, a2 and a3
are drawn off of packages which are stored in containers or the
like (not shown) immediately to the side of the continuous line of
equipment. The fiber elements are drawn from their sources and
arranged in side by side, parallel relationship by passing over a
horizontally extending guide bar 368 and between upstanding
longitudinally spaced guide pins 370 extending from the guide bar.
The guide bar and its upstanding pins are mounted upon a
horizontally extending frame member 372 fixed to extend between the
vertical frame members 343 and 346'. As shown in FIG. 13, the guide
bar and its pins are positioned rearwardly of the tank which is
also suspended from the frame member 372 by a suitable bracket 373
secured to the tank and to the frame member. The continuous fiber
elements then are conducted around a series of tensioning guide
rods 374, 376, 378 and 380 arranged in vertically spaced
relationship. The guide rod 374 is positioned within the tank so
that the parallel arranged fiber elements passing around it are
impregnated with the resin composition. The four horizontally
extending vertically spaced guide rods have a common support plate
382 secured to the cross frame member 372. As shown in FIG. 12, the
top support rod is curved and is removably connected to the support
plate by a nut 384 to allow the presentation of either a concave or
a convex surface to the impregnated band of parallel arranged
fibers prior to their being wound onto the conveyor tube. Band
width control is obtained by changing the orientation of the curve
as provided by the adjustable guide rod in relation to the incident
band. A convex surface provides a wider band and a concave surface
provides a narrower band.
The coated conveyor tube now covered with a band of substantially
circumferentially wound resin impregnated fiber elements then
advances to the station where a layer of parallel arranged
continuous fiber elements are helically wound into the assembly at
a lower angle of opposite hand by the first winding head I1. The
winding head is a device which supports a plurality of spools of
continuous fiber elements and which rotates around the partially
fabricated pipe assembly at a controlled speed acting to rotate the
pipe assembly which, as it rotates, is advanced in an axial or
longitudinal direction. The relative motion of the pipe assembly
with respect to the winding head or heads establishes the angle
that the fiber elements are wound into the pipe assembly. The
relative motion between the pipe assembly and the rotating winding
head causes the fiber elements to pay off the spools and cover the
conveyor tube and the initial layer a of fiber element
windings.
As shown in FIGS. 14-17, a winding head 11 (the three winding head
I1, I2 and I3 are identical) comprises an annular U-shaped channel
386 having rings 387 secured as by welding to the outer ends of the
channel's arms (FIG. 17). A pair of laterally spaced annular plates
388, 388' are welded to the base portion of the channel member. A
series of equidistantly spaced, circumferentially arranged spindles
390 are secured to extend from the annular plate member 388 and
similarly, a series of spindles 390' are secured to extend from the
annular plate 388'. The spindles which are each provided at their
outer ends with a washer and screw means are adapted to receive
spools of glass rovings or the like. The comparatively large
central opening on the inner diameter of the annular plates 388,
388' is provided with four equidistantly spaced, radially extending
guide support plates 394 which are welded to an internal ring 396
bridging the inner ends of the annular plates 388, 388' to thereby
provide guide support means as a part of the winding head. The four
equidistantly spaced guide support plates 394 have the
configuration shown in FIG. 15 and are secured as by welding to the
internal ring 396. The winding head has a central opening 397. As
shown, a portion of each plate 394 extends rearwardly of the
channel member 386 and its associated plates 388, 388'. The major
length of the guide support plates, however, extends forward of the
channel member 386 and its associated plates.
As best shown in FIG. 16, the continuous fiber elements or strands,
after being drawn off of the spools, first pass around a ring guide
398 and a guide 399 for the strands pair off from the spools on the
rear side of the winding head. Then, each of the fiber elements or
rovings passes through a ring provided with circumferentially
spaced eyelets 400, one eyelet for each roving. The rovings then
run over the ring guide 402, around the adjustable tension guide
ring 404, over the guide ring 406 and around through the central
opening 403 in a guide plate 408. The adjustable guide ring 404 is
secured as by welding to brackets 405, there being one bracket for
each plate 394. The brackets are each secured by a bolt in one of a
series of holes 407 in the respective plates 394. The guide plate
408 is secured to the lower ends of the circumferentially spaced
brackets 405. Except for the adjustably mounted guide ring 404, the
guide rings 398, 399, 402 and 406 and the ring providing the
support for the eyelets 400 are fixed to the plates 394. The center
of the winding head at the opening 403 allows the conveyor tube
with the wound layer or layers thereon to pass centrally through
the head for the application of a layer b1, or layers b2 and b3,
upon such generated portion of the pipe assembly.
As shown in FIGS. 14 and 15, each winding head is supported for
rotation by a framework 410 which comprises a pair of transversely
spaced, vertical standards 412, 412' connected by pairs of
vertically spaced cross members 414, 414' at the top and bottom.
Angled bracing and load-bearing members 416, 416' extend between
the frame members 412 and 414' on opposite sides of the frame
structure. The angled members have mounted thereon loadbearing
rollers 418, 418', each comprising spaced pairs for engagement with
the spaced rings 387 forming the rims of the winding head. The
bracing members also are used to support bearing members 420, 420'
which are received intermediate the arms of the U-shaped channel to
maintain the winding head on center as it rotates. A third
positioning bearing 420" is located centrally from the top cross
member 414. The winding head with a full complement of spools
mounted thereon and the described guide means for the plurality of
fiber elements is rotated by the drive shaft 266 which rotates a
pulley 422 fixed to the shaft. A belt 424 extends around the pulley
and is received and bears against the base portion of the U-shaped
channel 386 to rotate the winding head at a selected rate of
rotation depending upon the size of the pulley 422 for a given rate
of rotation of the drive shaft 266. Preferably, a tension wheel 425
mounted on the cross member 414 is provided to take up any slack in
the belt 424.
With the winding heads I1, I2 and I3 positively rotated about the
pipe assembly as it is generated, and with the substantial forces
to be overcome in drawing off the fiber elements under tension from
a number of spools sufficient to provide the bands b1, b2 and b3
each of a width substantially equal to the circumference of the
generated portion of pipe assembly, the winding heads act to rotate
the rotatably mounted pipe assembly. The parallel arranged fiber
elements drawn off each powered winding head pass through the
central opening 403 in the form of a frusto-conical structure
before the fiber elements are laid into the pipe assembly and with
a device J located immediately adjacent each winding head as shown,
the fiber elements are engaged by the aforementioned wheels 352,
360 and 364. As a result, a resin coating is applied to the fiber
elements by the coating or impregnation wheel 352 as the moving
tapered arrangement of fiber elements revolves in contact with the
wheel. The same bath used to coat the fiber elements for a layer a
coats the elements for a layer b. The support wheel 360 acts as a
support for the generating pipe, and by its rotation also causes
the fiber elements of the frusto-conically arranged, parallel fiber
elements to be flexed, thereby assisting to force resin composition
into the travelling fiber elements. The associated guide wheel 364
also functions to impart flexure to the moving fiber elements as
they pass under the wheels and are wound onto the conveyor tube
with its previously applied layers of fiber elements. At the pair
of associated devices J1-I1, a band b1 of resin impregnated
continuous fiber elements wound at a relatively low angle is
immediately overwound by a band a1 of resin impregnated continuous
fiber elements applied at a substantially high angle and of
opposite hand. Similarly, the bands or layers b2-a2 and b3-a3 are
applied from the associated devices I2-J2 and I3-J3, respectively.
The resin coating or impregnant is preferably a thermosetting resin
composition such as an epoxy resin composition and a suitable
hardener or a polyester composition.
When the generated pipe assembly passes the station of the last
group of related devices I3-J3, the pipe assembly moves under a
heater 426 to cure the resin impregnant for the fiber elements in
the various layers which have been incorporated into the pipe
assembly. As shown in FIGS. 2C-3E, the heater is suspended from
straps 428 connected to the central upper frame member 54 so that
the heater is located immediately adjacent the advancing pipe
assembly. The pipe assembly then passes into an oven 430 which may
have a communicating blower 432. The pipe assembly then passes
through a cooling device 433, whereupon the pipe assembly is in a
condition suitable for field use. The pipe assembly however is
utilized to furnish an operating part of the apparatus which
continuously manufactures the pipe assembly.
As will be evident from FIGS. 1-1B and FIGS. 2-3E, the control
means D and the inflatable seal means E are the next devices
forward in the line provided by the apparatus. It is believed,
however, that the invention may be best explained by now describing
the functions of the air under pressure which is conveyed through
the mandrel by means of the tube 57 and its extensions 57', 328 and
342. The aforementioned seal means B may be located anywhere beyond
the station where the conveyor tube is formed on the mandrel. Such
seal means may be provided at a point just prior to the location of
the first device J where the layer a is applied. The conveyor tube
is sufficiently rigid to withstand the tension of the windings
applied from the device J. As shown in FIG. 1A, it is preferred to
locate the seal means B forward of the first winding head I1. While
the end 50 of the mandrel may be located at any point forward of
the seal means B, it is preferred that the end of the mandrel be
located immediately following that point on the mandrel where the
winding head 13 is located or rearward of the control means D. The
air under pressure within the pipe assembly, and down from the
mandrel, acts to resist the pressure of means gripping the pipe
assembly provided by the control means D.
As previously indicated, the primary function of the air under
pressure is to impart an axial thrust to the pipe assembly as it is
being fabricated to continuously advance the assembly through the
apparatus. It will of course be understood that when the apparatus
is started, a dummy length of pipe may be used to initiate
operation of the equipment. When the forward extremity of the
generated pipe assembly is beyond the control means D and the
inflatable seal means E, plug seal means C is used to seal the
forward end of the pipe assembly so that a rigid body is provided
against which the force of the fluid or air under pressure may
exert its thrust. While any suitable plug means may be used, it
will be apparent that a very strong, air-tight connection must be
made between the end of the pipe assembly and the plug. A plug
construction which is particularly serviceable for the purpose and
which is preferred is shown in FIGS. 18-21.
As illustrated, the plug seal means C comprises an annular bearing
plate 434 having a central, internally threaded opening 436. A hand
wheel 438 is provided with a longitudinally extending externally
threaded shaft 440 which extends through the mating internally
threaded opening 436. The hand wheel and the shaft are fixed for
rotation together by a torque pin 442. The forward end of the shaft
has a disk 444 fixed to it of a larger diameter than the diameter
of the shaft for engagement with a shoulder 446 provided by an
inner plug 488. An O-ring 450 is positioned adjacent the rear side
of the disk for sliding sealing engagement with the wall of a
central bore 452 extending rearwardly of the shoulder 446. The
O-ring is confined between the disk and an annular flange 453
formed on the shaft 440. The plug 448 is hollow and has a
counterbore 454 of larger internal diameter in communication with
the smaller bore 452, whereby the disk 444 has clearance when the
hand wheel is turned to cause axial movement of the shaft 440 and
the unseating of the disk from the shoulder 446. A stop collar 456
is fastened to the shaft 440 to limit the extent of rotation of the
shaft to its unclamped position (FIG. 19), the collar engaging an
internal shoulder 458 provided by the plug 448.
As shown in FIGS. 18 and 19, the plug 448 is formed to provide a
frusto-conical outer surface whereby a ramp 460 is provided
converging in taper from the end 462 of the plug rearwardly toward
the bearing plate 434. A split, expandible sleeve comprising a
plurality of segments 464 overlies the plug 448. As shown in FIG.
20, four split sleeve segments may be used, and as illustrated,
each segment is connected to the bearing plate 434 by a bolt 466
extended through an aperture 468 in the bearing plate. The bolt for
each segment is matingly threaded into a threaded bore 470 provided
to extend longitudinally in each segment, and locked by a set screw
471 so that the head of each bolt is spaced from the bearing plate.
The apertures 468 in the bearing plate however are of a diameter to
furnish clearance with the shanks of the bolts 466 whereby the
segments furnishing the annular split sleeve may possess movement
in a radial direction. An elastic retaining ring 472 of rubber or
the like encompasses the sleeve segments to resiliently maintain
the segments against the underlying plug 448. Each segment is
formed so that its inner surface has a taper for mating engagement
with the plug's ramp 460. The external surface 474 of each segment
is roughened as by knurling or the like to furnish a gripping
surface for engagement with the internal surface of the pipe. An
elastic O-ring 476 located to surround the plug 448 at the forward
edge of the split, expandible sleeve assembly prevents air leakage
between the inner plug and the pipe assembly when the plug seal
means C is in operative position and clamped within the forward and
of the pipe assembly P (FIG. 18). Circumferentially spaced, air
venting openings 478 are provided in bearing plate 434 to place the
interior of the plug 448 in communication with the ambient
atmosphere when the O-ring 450 is moved out of the bore 452 (FIG.
19). To assure continued venting though the stop collar may be in
engagement with the shoulder 458, vent holes 480 may be extended
through the collar.
The operation of the plug seal means C will be apparent by a
comparison of FIG. 18 showing the device in its pipe clamping
position and FIG. 19 showing the device in its unclamped position.
With the device in its unclamped position, the split, expandible
sleeve is on its smallest diameter since the segments 464 are
positioned on the smaller diameter of the tapered ramp 460. When
the hand wheel 438 is rotated to clamp, the plug is drawn inwardly
within the split, expandible sleeve so that the segments 464 ride
up on the ramp 460 until the knurled surfaces 474 grip the inner
surface of the pipe assembly with a firm, air-tight seal. Such
relative motion of the parts causes the elastic, retaining ring 472
to increase in diameter. In clamped position, the disk 444 engages
the shoulder 446 and the O-ring 450 is in sealing engagement with
the wall of the bore 452. When the hand wheel 438 is turned in an
opposite direction to unclamp the device from the pipe, the O-ring
seal 450 is unseated from the wall of the bore 452, and causes the
venting of the air pressure within the pipe assembly through the
communicating openings 478. The parts are dimensioned so that such
venting takes place while the knurled segments still maintain their
grip on the pipe assembly, thereby preventing the device from being
blown out of the pipe. Further rotation of the hand wheel allows
the bearing plate 434 and its connected sleeve segments to force
out the inner plug 448, the elastic retaining ring 472 acting to
contract and thereby reduce the diameter provided by the gripping
segments so that the grip upon the pipe assembly is released.
With the plug seal means C clamped onto the forward end of the pipe
assembly, the air under pressure in the main air line 57 and its
extensions passes out through the end 50 of the mandrel and into
the generated pipe assembly to exert pressure against the plug seal
means C to advance the pipe assembly in an axial direction. this
axial force is opposed by the axial force component of the
continuous fiber elements being pulled onto the pipe assembly at
the stations where the devices J, J1, J2 and J3 are located; also,
the coated strip or strips d furnish an opposing axial force
component. The control means D located rearwardly in the line from
the forward extremity of the pipe assembly is a device which
synchronizes and controls the rate of advancement and the rate of
rotation of the pipe assembly. The device engages the rotating pipe
assembly to revolve with it; the device as a whole does not travel
with the pipe assembly. The synchronization and control device D is
constructed to add or subtract linear work from the system by
maintaining the rate of linear advancement of the pipe assembly in
a constant relationship with respect to the pipe assembly's rate of
rotation. Such fixed relationship establishes the winding angle for
the fiber elements constituting the hoop windings in the layers a,
a1, a2 and a3. When the correct relationship of rate of linear
advancement to rate of rotation of the pipe assembly is
established, the synchronization and control mechanism neither
takes work out of the system to retard pipe advancement, nor does
it put work into the system to increase the rate of pipe
advancement. However, when the axial thrust imposed by the air
pressure to advance the pipe assembly is not in the correct
relationship to the assembly's rate of rotation, the
synchronization and control means D, which is responsive to the
rate of advancement of the pipe assembly, compensates the system by
putting work in or taking work out to thereby maintain the desired
constant relationship of linear travel to rational movement of the
pipe assembly.
As shown in detail in FIGS. 22-26, the control means D comprises an
annular main support frame 482 in the form of a pair of spaced
plates 484, 484' secured in desired spaced relationship by a
plurality of circumferentially located spacers 486. The main
support frame has a central opening of substantial size. A bolt 488
is extended through the frame plates and each of the spacers. The
main support frame is supported for rotation within a load-bearing
framework generally designated 490 which comprises a pair of
transversely spaced standards 492, 492' connected to one another by
the vertically spaced top and bottom cross frame members 494, 494'.
As shown in FIGS. 2E and 3E, the supporting framework 490 is
secured to a channel framework 496 which is positioned on the floor
and braced by angle irons 498, 498'. Angle bracing members 500,
500' are connected to extend between the standard 492 and the
bottom cross frame member 494 and between the standard 492' and the
bottom cross frame member.
As shown in FIG. 25, bracing members 500, 500' each have mounted
thereon the load-bearing rollers 502, 502', respectively, to
rotatably support the annular main support frame 482. To guide and
maintain the support frame in a fixed plane of rotation, three
equidistantly spaced guide rollers 504 are mounted to extend
between the frames' spaced plates 484 and 484'. As shown in FIG.
26, each guide roller is of the ball bearing type and is secured to
a stub shaft or thrust rod 506 as by clamping a washer 508 to the
inner race by a bolt 510 threaded into the end of the stub shaft.
The opposite end of the stub shaft is fastened to the stationary
framework. As shown in FIGS. 25 and 26, the top guide roller is
bolted to a tie bar 512 extending between spaced frame members 514,
514' which also furnishes a support for a pillow block 516 for the
drive shaft 266 (FIG. 3E). The drive shaft which actuates the
aforementioned winding heads I1, I2 and I3, also the conveyor tube
forming device or devices G, also actuates the control means D. As
shown in FIG. 25, the other two guide rollers 504 are mounted at
the ends of their respective thrust rods 506 which are welded to
brackets 518, 518' respectively secured to the standards 492, 492'.
As will subsequently appear, the guide roller and thrust rod
arrangements in the illustrated spaced relationship, additionally
function to sense axial thrust which may be imposed upon the main
annular support frame 482 by the control device D.
As shown in FIGS. 2E and 3E, the annular main support frame 482 is
rotated by the drive shaft 266 through a chain 520 cooperable with
a sprocket 522 fixed to the shaft. The chain 520 extends around a
plate sprocket 524 which has a central opening of substantial size
and which is of a slightly larger diameter than the annular frame
support 482 adjacent to which it is mounted. The sprocket 524 may
be termed the rotary control sprocket. The sprocket and the
adjacent annular frame are connected to one another for rotation
together in any suitable manner, for this purpose,
circumferentially spaced spacers 526 may be provided and held in
position by the same bolts 488 as used for the spacers 486.
As shown in FIGS. 22 and 25, a hollow chassis 526 is positioned
centrally of the support frame 482 and the rotary control sprocket
524. The chassis may be cylindrical in form. As illustrated
however, it is preferred that the chassis be provided with
intersecting sides to facilitate the assembly therewith of the
parts to be described. As shown, the chassis is substantially
square-shaped and has four sides so that a pair of spaced,
longitudinally extending channel member 530, 530', 532, 532', 534,
534', and 536, 536' may be respectively secured to each side of the
chassis. The channel members extend forward and rearward of the
chassis (FIG. 22) and the hollow character of the chassis allows
the pipe assembly P to pass through the chassis and the control
device D.
Resilient annular members are mounted to grip the outer periphery
of the pipe assembly at spaced areas about the rotating and
linearly advancing pipe assembly P, the resilient members being
mounted to revolve as a unitary assembly with the rotating pipe
assembly and for independent rotation about their respective axes
of rotation. As illustrated in FIGS. 22 and 25, the resilient
annular members are in the form of tires each of which is mounted
upon the aforementioned longitudinally extending channel members
which are fixed to rotate with the rotary support frame 482 and the
rotary control sprocket 526. With a four-sided chassis, there are
four pairs of longitudinally extending support channels and four
pairs of tires 540, 540', 542, 542', 544, 544' and 546, 546'.
Preferably, the tires are of the inflatable or pneumatic type to
thereby afford, by the air pressure in them, means for adjusting
the gripping pressure upon the pipe assembly. It will be understood
that the number of pairs of tires is a matter of choice. Instead of
four pairs, as illustrated, the device is operable with three pairs
or more than four pairs depending upon the diameter of pipe being
processed. Between the channel members 530, 530', the axle for the
rear tire 540 is journaled in pivot brackets 548, 548' secured to
the channels 530, 530', respectively. The front tire 540' is
similarly mounted between this pair of channel members. The tires
542, 542', 544, 544' and 546, 546' are similarly mounted by
brackets extending from the pairs of channel members 532, 532',
544, 544' and 546, 546', respectively. The channel members are each
fastened as by welding to a pair of rings 550, 550' which are
bolted to each side of the rotary control sprocket 524. Such
arrangement allows the ready replacement of a worn sprocket without
disturbing the connected assembly of chassis, longitudinally
extending channel members and the spaced, resilient, rotatable pipe
engaging elements or tires.
FIG. 23 illustrates how a tire, in this case tire 546, is mounted.
The other tires of the assembly are mounted in the same manner. An
axle 552 is fixed to extend between the brackets 548, 548' at one
end of a pair of channel members, in this instance, the channel
members 536, 536'. A hub 554 is rotatable about the axle, the hub
having bearings 556 and 556' in each end. The hub has an ear 558 in
the middle of its length to which flanges 560, 560' are bolted at
652. The flanges extend from a rim 564 for the annular resilient
member or tire. The hub 554 is also provided with a flange 566 at
one end thereof to which a sprocket 568 is bolted at 570. Each of
the eight tires is similarly mounted for rotation about a fixed
axis, and is provided with a sprocket 568.
Each of the longitudinally spaced tires 540, 540', 542, 542', 544,
544' and 546, 546' is driven off the same drive shaft 266 which
rotates the described rotatable assembly, which includes the tires
as parts of such rotatable assembly, to furnish axial control of
the pipe assembly P gripped by the tires. As shown in FIGS. 2E and
3E, a second drive is brought off the drive shaft 266 through a
second drive chain 572. The chain 572 passes around a sprocket 574
fixed to the shaft 266, and as shown in FIGS. 22 and 25, such chain
is cooperable with a sprocket 576 which may be termed an axial
control sprocket as distinguished from the aforementioned rotary
control sprocket 524. Like the rotary control sprocket, the axial
drive sprocket is in the form of a plate and has a central opening
of substantial size to permit the chassis 528 to extend
therethrough. The sprocket 576 however, also has internal teeth
(FIG. 24) for cooperation with sprockets 578 on the input shaft of
each of four differentials or gear reducers 580 which are
circumferentially arranged for cooperation with the illustrated
four pairs of tires. To confine the sprocket 576 to a fixed plane
of rotation, the sprocket has guide rings 581, 581' bolted to its
sides, the rings extending to each side of the circumferentially
arranged, equidistantly spaced sprockets 578 on the input shaft of
each gear reducer. Each gear reducer is held in a fixed position on
the rotatable assembly by being fastened to a side of the
four-sided chassis 528. On the output side of each gear reducer,
two sprockets 582 and 584 are fixed to the same output shaft. A
sprocket chain 586 extends over the sprocket 582 and the sprocket
568 for each rear tire, thereby driving the rear tires 540, 542,
544 and 546 in unison since the gear reducers are all of the same
ratio. Also, a chain 588 extends over the sprocket 584 of each gear
reducer and the sprocket 568 for each front tire 540', 542', 544'
and 546' to drive them at the same speed as the rear tires.
As will be apparent from the foregoing described relationship of
the parts of the control means D, the resilient, annular members or
tires grip the pipe assembly advanced centrally therethrough while
rotating bodily with the rotating pipe assembly P. The rotary
motion imparted to the tires about their respective axes of
rotation through the medium of the axial drive sprocket 574, its
associated gear reducers or differentials 580, and the chain and
sprocket connections to the individual tires, furnishes a control
for the axial movement of the longitudinally advancing pipe
assembly. Axial movement of the pipe assembly may be interrupted
when desired by disconnect means 589, one part of which may be
slidably mounted on the shaft 266 and the other part fixed to the
sprocket 574 when a spline type of disconnect means is used. Under
pressure, the air within the pipe assembly acts to resist the
pressure upon the pipe assembly which is imposed by the tires which
firmly grip the outer periphery of the rotating and longitudinally
advancing pipe assembly.
As previously indicated, the arrangement of guide rollers 504 and
their respective stub shafts or thrust rods 506 have an additional
function; they act to sense undue thrust which may be imposed upon
the main support frame 482 and the described associated parts which
are assembled therewith. As shown in FIG. 26, the thrust rod
extends through aligned openings 590, 590' on opposite sides of a
housing 592 suitably fixed to the stationary framework 490. The
thrust rod is provided with a cavity 594 extending into a side
thereof intermediate its length within the housing, the cavity
terminating in stop 596. A thrust piston 598 has a central shaft
portion 600 the end of which is received within the cavity 594 with
its extremity 602 engageable with the stop 596. The shaft 600
extends through an aperture 604 in the side wall of the housing
592. An annular, externally threaded mounting sleeve 606 is secured
as by welding to the wall of the housing to surround the aperture
604. The piston 598 is positioned for reciprocation within a
cylinder 608 which is internally threaded at the rear portion
thereof for connection to the mounting sleeve 606. An O-ring 610 is
positioned in a groove formed around the head of the piston to
prevent fluid leakage. A hydraulic fluid, such as oil, is contained
within the cylinder 608 between the head of the piston and flexible
hoses 612 connected by suitable fittings into the internally
threaded openings 614, 614' formed in the end wall 616 of the
cylinder.
As shown diagrammatically in FIG. 26A, three assemblies such as
shown in FIG. 26 and designated D' are interconnected to one
another by the hoses 612, and a pressure sensing instrument or
gauge 618 is tied into the line to sense any undue axial thrust
which may be imposed upon or by the control device by the pipe
assembly. Undue axial thrust is sensed when anyone of the three
thrust rods 506 is unduly deflected about its cantilever connection
to the stationary framework. Such deflections is converted through
the pistons 598 into hydraulic pressure. Variance from a
predetermined gauge reading indicates that the axial thrust imposed
by the rollers 504 upon either of the rings 484 or 484' of the main
support frame 482 is out of balance. Appropriate correction is made
by adjusting the air pressure acting to impart axial thrust to the
pipe assembly, or by adjusting the tension level on the rovings
being applied from the winding heads I, I2 and I3 which rotate the
pipe assembly. The latter adjustment is made by changing the
positions of the adjustable tension guide ring 404 on each of the
winding heads. As previously indicated, the drive shaft 266
actuates the control means D as well as serving to rotate the
winding heads I1, I2 and I3, also the conveyor tube forming device
or devices G. The motor 258 which rotates the drive shaft either
puts energy into the control device or acts as a brake when the
system would tend to get out of balance, balanced conditions being
a predetermined ratio of rates of linear advancement and of
rotation of the pipe assembly. Since the same motor, or its shaft,
actuates the operations of aforementioned devices for incorporating
material into the pipe assembly as well as serving to actuate the
control device, temporary deviation from optimum balanced
conditions does not seriously affect the pipe assembly being
generated; the operation of all of the devices is synchronized from
the same driving means to equally affect each device.
The aforementioned inflatable means E is positioned within the pipe
assembly P and forward of the control means D, as shown
schematically in FIG. 1B. The inflatable means which, in effect, is
an air piston, is shown in detail in FIGS. 27-34. The air piston is
a device which furnishes a temporary, longitudinally advancing,
internal air seal within the pipe assembly a set distance
rearwardly from the end of the pipe while the pipe is being
manufactured or generated. As previously described, the pipe
assembly in the normal course of continuous manufacture is
air-sealed at its forward moving end by the plug seal means C, the
air seal B over which the pipe assembly is drawn furnishing the
other end of the air sealed chamber. The air piston provided by the
means E permits cutting off a length of the pipe assembly from the
continuously manufactured product without the loss of air pressure
within the pipe assembly, and thereby the continuous manufacturing
process need not be interrupted. Activating the inflatable air
piston temporarily creates a linearly travelling seal within the
pipe assembly to allow the removal of the plug seal means C from
the end of the pipe, whereby a section or length of the otherwise
endless pipe assembly being generated may be cut on the
unpressurized side of the travelling air seal provided by the means
E. After a selected length of the pipe has been cut from the
continuously advancing pipe assembly, the plug seal means C is
replaced in the end of the pipe whereby the air piston is then
relieved of the air pressure which actuates or inflates it. While
such temporary air seal is operative, axial motion of the pipe is
maintained by the air pressure acting on this air piston form of
device or plug. When the air seal is released, the air piston means
B is automatically returned to its unpressurized and rest position
to await its next activation when a predetermined length of pipe
assembly is to be cut off from the endless pipe assembly being
generated. FIGS. 27-31 illustrate a pipe asembly P as related to
the inflatable seal means E. For convenience of illustration, the
pipe assembly is merely shown as a tube, for without some showing
thereof the related plug seal means C as shown in FIG. 28 would
have no visible supporting means. It will be understood that the
pipe assembly at this point in the line has the construction shown
in FIG. 35.
As shown in FIGS. 27-34, the temporary air seal means E comprises
an inflatable container 620 made of an elastic material such as
rubber. When not activated or not inflated, the container has the
form of a tube closed at each end, and has a diameter less than the
internal diameter of the pipe assembly which rotates and advances
over it. The clearance between the outer side of the inflatable
container and the surrounding pipe assembly permits the air under
pressure from the main air line to exert an axial thrust on the
plug seal means C (FIG. 28).
The inflatable container 620, for a portion of its length,
surrounds a rigid support sleeve 622 made of aluminum or the like
having a plurality of openings 624 in its wall to place the
interior of the support sleeve in communication with the interior
of the inflatable member. The inflatable member is held to surround
the support sleeve by forward end clamp means comprising an end
clamp 626 which is welded to the forward end of the support sleeve
622. The inflatable container is held by securing an end clamp 628
to the opposite side thereof, the clamping members 626 and 628
being held and secured to one another by a bolt 630 extended
through the clamp member 628 and threaded into the clamp member 626
through an opening in the inflatable air container. The opposite or
rear end of the inflatable container is clamped between a clamp
member 632 on the inner side and a centering guide 634 against
which is pressed a clamp member 636 by a nut 638. The nut is
threaded onto an externally threaded sleeve 640 which is secured as
by welding to an air conveying tube 642.
As best shown in FIG. 32, the air conveying tube 642 is in
communication with the apertured or perforated support 622
surrounded by the inflatable container 620. As shown in FIG. 33,
the air line 642 is in communication with the tubing 98 connected
to the second source of air back at the rotary coupling (FIG. 4).
As previously described, the tubing 98 rotates with the mandrel A
and extends beyond the mandrel's forward end 50 or the end where
the main air line 57 and its extensions terminate. The diameter of
the tubing 98 is smaller than the diameter of the tube 642. The end
of the tube 98 is flared at 644 to allow relative longitudinal
movement between the tubes, and to prevent them from being
separated.
As also shown in FIG. 33, the rearward end of the tube 642 is
fastened as by force-fitting into a guide hub 646 through which the
tube 98 extends. The guide hub is provided with an internal groove
within which is positioned an O-ring 648 to furnish an air seal
between the hub and the tube so that relative longitudinal motion
between the tubes 98 and 642 does not result in a loss of air
pressure. A guide 650 for centering the pipe assembly over which
the pipe assembly passes is secured as by screws 652 to the guide
hub. As shown in FIG. 30, the guide hub is provided with
longitudinally extending, circumferentially spaced holes 653 to
allow air from the main line to pass through the part and around
the deflated air container 620 for the application of thrust
against the plug seal means C. The guide hub is also provided with
a rearwardly extending annular flange 654 of a diameter to closely
surround the tube 98. The hub having the air tube 642 connected
thereto is slidable along the tube 98. As best shown in FIG. 34, a
coiled tension spring 656 has its forward end anchored to the hub
member by providing the flange portion 654 with annular grooves 658
within which several adjacent turns of the spring are force-fitted.
The spring acts to return the air piston assembly, or the apertured
support sleeve 622 and its surrounding air container 620, to
inactive position after the pressure in the line provided by the
tubes 98 and 642 is released to deflate the air container.
Accordingly, and as shown in FIGS. 27 and 28, the opposite or rear
end of the spring 656 is anchored in the same way as the forward
end, as above described, to a centralizer tube 660 which is secured
as by welding to the outer periphery of the air conveying tube 98.
The centralizer tube is secured to the air conveying tube 98 just
forward of the control device D. The centralizer tube has mounted
thereon a plurality of centralizer guiding ribs 662 with the ribs
at their highest points having a diameter slightly less than the
internal diameter of the pipe assembly which travels thereover and
is guided thereby.
After a section of pipe has been cut off, the plug seal means C is
clamped onto the forward end of the pipe assembly within the
apparatus. The air container 620 which was inflated to frictionally
grip the interior of the pipe assembly to rotate and travel forward
therewith is deflated by releasing the pressure in the air line
provided by the communicating tubes 98 and 642. The spring 656 acts
to return the assembly including the deflated container, also the
guide hub 650 and its associated parts, to a position adjacent the
centralizer tube and its guide ribs. Upon subsequent reactivation
of the air container 620, it becomes a travelling plug against
which the air under pressure from the main line 57 and its
extensions may exert an axial thrust to advance the thus
temporarily sealed pipe assembly. During such temporary seal of the
pipe, the plug seal means C is unclamped, a section of the pipe is
cut off, and the plug seal means is clamped into the forward cut
end of the advancing pipe assembly without interruption of the
continuous process.
An alternate embodiment of the means for providing the temporary
fluid seal is illustrated in FIG. 43. In this embodiment the
inflatable container 620, described above, is attached to the
forward end of a hollow rod 768 which is continuous over its entire
length and extends through the interior of the mandrel 57 and is
slidably and rotatably engaged with the rotary joint 774, which is
at the rearward end of the mandrel. The rotary joint 774 is
attached to a supply line 814 through which a fluid, for example,
air, is fed into the mandrel. The hollow rod 768 is attached at its
rearward end to a rotary fitting 770. The rotary fitting 770 is
connected to a supply line 772 through which air or another fluid
under pressure can be fed from a source (not shown) to expand the
inflatable seal means 620. The rotary fitting 770 is attached to
one end of a cable 776 which passes from the rotary fitting over a
pulley 778 and is attached at its opposite end to a weight 780. The
pulley 778 is attached to the supporting member 812 through which
the cable 776 and the rotary fitting 770 travel. The weight 780 is
positioned in a well (not shown) which preferably is filled with a
liquid such as oil, which dampens the movement of the weight 780.
The means for providing the fluid seal, as illustrated in FIG. 43,
is in an engaged and almost completely extended position such as
when it is utilized for cutting off a length of the generated pipe.
After a length of the generated pipe has been cut off and the plug
seal means C reinserted, the pressure on the fluid fed through the
supply line 772 is released, which causes the inflatable seal means
620 to deflate and disengage the walls of the generated pipe
assembly as previously described. The weight 780 in combination
with the cable 776 then causes the assembly of the inflatable seal
means 620, the hollow rod 768 and the rotary fitting 770 to retract
to the at rest position indicated in phantom in FIG. 43. The
processing of pipe by the described apparatus is automatic and
continuous. As shown in FIGS. 2A and 3A, a control panel 670 is
mounted on the longitudinally extending central frame member 54 for
indicating the conditions of and for controlling several devices in
the system. An indicating potentiometer 672 is provided to control
the temperature for the heaters 312 which serve to partially cure
the resin which provides the conveyor tube form of resin T. A
voltmeter 674 also connected to the heaters 312 serves as a
temperature read out device. A rotary selector switch 676 permits
temperature read out for any one of the plurality of heaters.
Control means 678 is connected to the motor 258 to control its
speed, and a speed indicator 680 furnishes a read out of the actual
rate of rotation of the motor's shaft 266.
Resin lined pipe produced by the specifically described automatic,
continuous line is illustrated in FIGS. 35 and 35A. As previously
indicated, the pipe construction, insofar as the number of layers
and the angles of winding of the fiber elements of the various
layers, is a matter of choice. Changes may be made in the system
for the structure of pipe desired.
The apparatus hereinbefore described produces pipe having a
continuous resin coating or layer on its interior supplied by the
conveyor tube T which was made an integrated part of the finished
pipe assembly. By modifying a portion of the described continuous
system, an air impervious conveyor tube T' may be provided which is
removed from the pipe assembly after the conveyor tube has served
its purpose of furnishing a base for the materials applied thereto
in the conveyor tube's advancement through the apparatus. Apparatus
utilizing a removable conveyor tube may produce pipe having a resin
inner liner or a pipe which is unlined.
The portion of the continuous system for making pipe with a
removable conveyor tube is schematically shown in FIG. 36 and the
structured portion in FIGS. 37 and 39. When such portion of the
apparatus at the beginning of the system is placed in line with the
remainder of the system as schematically shown in FIGS. 1A and 1B
and structurally shown in FIGS. 2A-3D, a continuous system is
provided for the automatic and continuous manufacture of a pipe
assembly having a removable conveyor tube T'.
Essentially, the conveyor tube T' is fabricated to furnish the
desired air impervious quality and the desired measure of rigidity
to withstand the forces of applying windings thereon under tension.
Also, as will be described, the conveyor tube includes as a part
thereof means in the form of a stripping wire which enables the
ready removal of the conveyor tube which, in this embodiment of the
invention, is included in the pipe assembly for processing purposes
only.
Referring to FIGS. 36, 37 and 38, the conveyor tube T' is formed on
the rotatable mandrel A which, as hereinbefore described, serves to
convey air under pressure therethrough to impose an axial thrust
for the longitudinal movement of the pipe assembly through the
system, also to support an auxiliary air line to the inflatable,
temporary plug E. A tube of paper is first formed on the mandrel by
applying a plurality of strips e to cover the mandrel. The strips,
four in number in the illustrated form of the invention, are
longitudinally applied to the mandrel from four rolls 682 which are
supported upon a sleeve holder 684 fixed as by welding to the
mandrel or the tube portion 57 thereof as best shown in FIG. 40.
The holder is provided with equidistantly spaced brackets 686 to
which the spindles 688 for the rolls of paper strip are connected.
The advancing pipe assembly of which the conveyor tube T' is a part
serves to draw the paper strips off the rolls so that the
longitudinal edges of the strips are in slightly overlapping
relationship. The longitudinally applied strips are guided to
assume such relationship by a guide member 690 provided with slots
692 extended therethrough as shown in FIG. 41. The guide member,
which is provided with a central aperture 694 to allow the tube
portion 57 of the mandrel to extend therethrough, is suspended from
longitudinally extending rods 696 having their rearward ends
fastened or welded to a pair of the roll holder brackets 686 (FIG.
39).
After the plurality of longitudinally extending paper strips e has
been laid onto the mandrel with their edges overlapped, the strips
are adhered to one another by an adhesive coating carried by a
strip f which is helically wound about them. The strip f prior to
being wound around the strips e passes over a coating roll 697
positioned in an adhesive bath 698 and is coated on one side. A
heater 700 is disposed over the portion of the conveyor tube
generated to dry or harden the adhesive. As shown in FIGS. 37 and
38, the heater is suspended from longitudinally spaced straps 702
secured to the upper central frame member 54.
As also shown in FIGS. 37 and 38, a pair of strips g and h
helically wound in the same direction about the material previously
applied to the mandrel, these latter two strips being drawn off of
rolls 704 and 706 mounted on stationary stands 708 and 710 adjacent
the line. The strip g is of an air impervious material such as
cellophane or vinyl resin film, and has an adhesive coating of a
thermosetting resin, such as an epoxy resin composition, applied
thereto by an applicator 712. The strip h is preferably of a porous
or absorbent material such as tissue paper. When both strips are
wound into the assembly and heat is applied as by a second heater
713, the resin migrates through the strip h, the layers are bonded
to one another and the tube is air impervious.
The portion of the conveyor tube T' thus far generated is then
helically overwound with two strips i and j, rolls of which are
mounted on a rotating head generally designated 714. The strip i is
of paper and the strip j is of a parting or mold release material
such as a smooth tape of polypropylene, Teflon or the like. The
paper strip i is bonded to the generating conveyor tube through the
medium of the resin adhesive which has passed to the outer side of
the porous strip h. The rotating head 714 also has mounted thereon
a reel 716 from which a strong filament or wire k is drawn off and
wrapped around the generated tube to lie adjacent the layer
provided by the wound tape i. Incorporated in the conveyor tube,
the stripping element or wire k lies at an angle of approximately
45.degree. with respect to the longitudinal axis of the tube. When
the pipe assembly of which the removable conveyor tube T' is a part
has been completed, pulling or applying tension to the stripping
wire k causes the destruction of the removable conveyor tube for
its easy removal from within the pipe assembly. The mold release
layer provided by the tape j prevents adhesion of the conveyor tube
to the resin inner liner of the pipe if a resin lined pipe is made,
or to the resin impregnant on the first layer a of continuous fiber
elements wound into the pipe assembly at the station J forward in
the line. Due to the staggered relationship of the strips i and j
as they are being wound together, with the latter strip immediately
overlapped upon the former, the mold release layer is firmly held
on the outer side of the removable conveyor tube. The stripping
wire k is beneath the layer formed by the mold release strip j.
When, after the pipe assembly is completed and a pull is exerted
upon the stripping wire, the conveyor tube beneath the mold release
layer is cut or destroyed and the mold release layer because of the
character of the material readily comes away from the overlying
pipe structure.
As shown in FIGS. 38 and 39A, the rotating head 714 is suspended
from a bracket 718 secured at its upper end to the frame member 54.
The rotating head comprises a circular plate 719 having a central
opening to allow the generated conveyor tube to advance
therethrough. The rotating head plate has a pair of diametrically
opposed rearwardly extending rods 720, 720', each of which is
inwardly bent near their rear ends to furnish spindles for the
rolls of tape or strips i and j. A third rod 722 is welded to the
plate 719 and extends rearwardly and is formed to provide a spindle
for the wire wheel 716.
In the illustrated embodiment of the invention, as represented by
FIGS. 37, 38 and FIGS. 2A-3E, also as schematically shown in FIGS.
36, 1A and 1B taken together, the mandrel is positively driven or
rotated, whereas in the embodiment of the invention illustrated in
FIGS. 2-3E and schematically in FIGS. 1, 1A and 1B, the mandrel
though mounted for rotation is not powered or positively rotated.
It is preferred to positively rotate the mandrel in synchronism
with the rotation imparted to the pipe assembly in each of the
illustrated embodiments of the invention. Where the pipe is
processed upon a conveyor tube of the removable type, it is
particularly desirable to positively rotate the mandrel by bringing
the drive from the motor 258 rearwardly to the beginning of the
line where, in addition to the drive mechanism coupled to the
mandrel, a positive drive may be provided for the rotating head
714.
As shown in FIGS. 38 and 39A, the plate 719 of the rotating head is
mounted for rotation upon a stepped hub 724. The hub has the
portion thereof of larger diameter abutted against the bracket 718
with its portion of smaller diameter extended through the central
opening of the plate 719. A plurality of circumferentially arranged
screws 726 are extended through the bracket and screwed into the
hub to affix the hub to the bracket. On the opposite side of the
plate 719, a retaining plate 728 is secured into the stepped
portion of the hub by screws 730. A pulley 732 having a hub 734 is
sandwiched between the plate 719 and the larger diameter portion of
the hub 724. The pulley is fixed for rotation with the plate 719 by
screws 736 extended through the plate and into the pulley hub
734.
The winding head 714 is rotated by a belt 738 around the pulley 732
and around a second pulley 740 fixed to a countershaft 742
journaled in pillow blocks 744, 744' supported by the bottom frame
52, as shown in FIG. 38. The countershaft is rotated by the driven
shaft 268 previously referred to in connection with the first
described embodiment of the invention, and which, as previously
described, is driven by the motor 258. The shaft 268 and the
countershaft 742 are provided with pulleys 746, 746' and a
cooperating belt 748. The shaft 268 extends further rearwardly in
the line with the end of the shaft journaled in a pillow block 750.
The shaft 268 supplies power to rotate the mandrel A through a
series of pulleys and belts. A pulley 752 is fixed to the shaft 268
for cooperation with a pulley 754 fixed to a stub shaft 756. A belt
758 is cooperable with the pulleys 752 and 754. The stub shaft
which is suitably mounted for rotation in pillow blocks is provided
with a pulley 760 cooperable by means of a belt 762 with a pulley
764 fixed to the mandrel or its tube portion 57.
The described drive mechanism, all off the same motor 258, imparts
rotation to the winding head 714 so that the rotation of the
mandrel is synchronized with the rotation of the rotating head 714
applying the tapes i and j to the generating, removable conveyor
tube T'. It is preferred that the drive means for the winding head
714 be arranged so that the winding head shall rotate at a faster
rate than the rate of rotation of the mandrel to provide a wrap
angle of less than approximately 45.degree.. As shown in FIGS. 37
and 38, the completed removable conveyor tube T' may be overwound
by a helically applied strip l impregnated or coated on both sides
with a thermosetting resin composition applied by resin applicator
766 to furnish a resin liner for the completed pipe (after the tube
T' is removed). If desired, the resin liner layer provided by the
impregnated strip l may be omitted, whereby the finished pipe
comprises the plurality of layers of resin impregnated continuous
fiber elements applied by the devices J, J1, J2, J3, I1, I2 and I3
forward of the portion of the line where the conveyor tube is
formed on the mandrel.
Another embodiment of the invention where the conveyor tube is
removable is illustrated in FIG. 43, the conveyor tube being
designated 782. A tube winder 784 is rotatably mounted about the
mandrel 57 on the support 786 and is driven by a chain and sprocket
drive 790. The tube winder 784 comprises mounts 792 for holding
rolls of tape 794, 796 and includes guides 798, 800. When the tube
winder 784 is rotated about the mandrel 57, tapes 794, 796 are
helically wound on the mandrel to provide a helically wound
conveyor tube 782 on the mandrel. If desired, a single tape may be
wound on the mandrel with the edge slightly overlapping to provide
the conveyor tube.
The strip material that is employed to furnish the removable
conveyor tube is nonadhesive on its inner surface to the mandrel 57
and is, or can be, readily made adhesive on its outer surface. The
interior is nonadhesive so that the conveyor tube will be free to
advance over the mandrel as the conveyor tube is advanced. The
opposite or outer surface of the tube is coated with a separable
adhesive, that is, an adhesive effective to adhere the tube to the
resin composition of the pipe and which will allow separation of
the tube from the resin composition in its polymerized or partially
polymerized state upon treatment with a separating agent. The
separating agent is of a character or composition which does not
affect the polymerized or partially polymerized resin
composition.
In greater details, rolls of gummed kraft paper tape 794, 796 are
loaded onto the tube winder 784. The tapes are then helically wound
on the mandrel 57 with the adhesive side out and the uncoated side
toward the mandrel. To eliminate as much of the friction as
possible between the conveyor tube 782 and the mandrel 57, the
mandrel 57 may be coated with Teflon. Since the adhesive surface is
not adhesive in the dry state, the outer surface of the tube 782 is
sprayed with a fine mist of water from a shower head 802. The
water, in addition to moistening the adhesive on the tape, somewhat
dampens the paper and makes it more plastic so that it will conform
more smoothly to the contour of the mandrel 57. After the conveyor
tube 782 is moistened, it is dried by advancing it through an oven
804. A resin liner 806 is applied to the conveyor tube from the
nozzle 808. The resin liner 806 readily adheres to the dried
adhesive surface of the conveyor tube 782. The conveyor tube coated
with the resin liner 806 is then advanced into a second infra-red
oven 810 in which the resin liner is at least partially cured, and
is thereby made air impervious. The remainder of the glass and
resin build-up is then applied to the coated conveyor tube. After
the pipe assembly is completed, the conveyor tube 782 is removed
from the finished pipe by simply soaking the pipe in warm water or
by the use of steam under pressure, which softens and dissolves the
gummed adhesive and enables the paper tapes to be easily removed.
If desired, the conveyor tube may be left in the finished pipe to
protect the inner resin liner until the pipe is ready for
installation, whereupon the conveyor tube is removed in the field
as above described just prior to installation of the pipe.
It will be apparent that the above technique is not limited to the
use of the preferred water-soluble adhesive coated kraft paper and
that other materials having the above-noted properties may be used
in lieu thereof. The carrier strip may be a solvent-permeable film,
and the separable adhesive may be a solvent activatable
composition, whereupon the conveyor tube is removed by soaking the
tube lined finished pipe in a solvent bath in which the separable
adhesive is soluble, but in which does not affect the finished pipe
assembly. Paper tape coated with a water-soluble adhesive is
preferred because of economy and ease of removal with water or
steam.
The apparatus shown in FIG. 43 may also be employed to manufacture
pipe in which the conveyor tube becomes an integral part of the
finished pipe. In this embodiment of the invention, tapes are
initially prepared by resin impregnating a suitable base material
such as fiberglass tape. The resin impregnated material is then
preferably cured to a B-stage. The inner surface of the resin
impregnated tape will not adhere to the Teflon coated mandrel 57
when wound on the mandrel. However, in order to insure nonadhesion
to the mandrel 57, a mold release agent such as graphite can be
applied to the inner surface of the tape or sprinkled on the
mandrel 57 as the tapes are wound onto the mandrel 57. The outer
surface of the tape can be made adhesive by several different
techniques. The outer surface of the resin impregnated tape can be
coated with a suitable semicured thermosetting adhesive resin. In
addition, with certain resins, a fine mist of selected solvents can
be applied to the conveyor tube from the shower head 802, which
makes the outer surface adhesive in a manner similar to that noted
above the gummed kraft paper tube. Resinous materials may also be
employed which when initially heated in the oven 804 will become
somewhat softer and adhere to the surface of adjacent tapes before
the resin advances in cure from the B-stage to the C-stage. An
additional method of forming the integral air impervious conveyor
tube is to coat the helically wound resin impregnated tape with a
coating of resin 806 from the nozzle 808, and at least partially
cure the resin coating so as to completely seal the outer wall of
the conveyor tube. Once the conveyor tube is formed as noted above,
it is then further built up as indicated above to provide the
finished pipe.
An additional embodiment of the present invention is illustrated in
FIGS. 46 and 47. Referring to FIGS. 46 and 47, the number 816
generally designates an apparatus for forming continuous
glass-reinforced plastic pipe in accordance with the present
invention. The apparatus 816 comprises a vertical stationary rigid
supporting member 818, which may comprise a portion of a suitable
supporting frame, not shown, said supporting member 818 being
formed with a horizontal projection 820 containing a horizontal
bore 822. Journaled axially in the bore 822, as by means of
suitable ball bearing assemblies 824 and 826, is rigid tubular
shaft 828 on which is coaxially mounted the pipe forming mandrel
830. As shown in FIG. 47, the mandrel 830 is located adjacent the
end of the projection 820 and is formed with longitudinally
extending supporting flanges 832 extending from the end of the
mandrel 830 parallel to and over the projection 820. The
longitudinally extending supporting flanges 832 are angularly
spaced uniformly around the axis of the mandrel 830, and each
longitudinally supporting flange 832 is formed with a radially
extending supporting flange 834.
Journaled on the end of each outwardly projecting radially
extending flange 834 adjacent to the supporting member 818 is a
feed roll 836 of adhesive coated cellophane tape such as Scotch
brand tape, and journaled on the radially extending flange 834
forwardly adjacent the feed roll 836 is a feed roll 838 of
cellophane strip material. The respective feed rolls 836 and 838
are so arranged relative to each other, and the strip material
carried thereon is of sufficient width, so that the cellophane
strips from the roll 838 can extend longitudinally onto the mandrel
830 with their side edges substantially in engagement with each
other and with their side margins overlapping and adhesively
secured on the strips of adhesive coated cellophane tape from the
roll 836, which are likewise laid longitudinally on the mandrel
830. Thus, the strips of adhesive coated cellophane tape are
designated in FIG. 46 at 840 and the side-by-side strips of
cellophane from the rolls 838 are designated 842.
Suitably journaled adjacent to the mandrel 830 on an axis which is
inclined at an acute angle to the axis of the mandrel is a supply
roll 844 of glass tape 846 impregnated with a thermosetting resin.
As shown in FIG. 46, the roll 844 is positioned so that the glass
tape 846 can be helically wound over the air tight envelope formed
by the cellophane strips 842 and the adhesive coated cellophane
tape strips 840 connecting their margins, the glass tape 846 having
its major strength in a substantially transverse direction so that
the finished pipe is provided with the required strength in its
axial direction.
The mandrel 830 is provided with a series of longitudinally spaced
annular peripheral air pressure equalizing grooves 848, 850 and
852, for a purpose presently to be explained, the groove 848 being
located nearest the left end of the mandrel 830, as viewed in FIG.
47. The glass tape 846 is applied to the mandrel at a location
substantially between the groove 848 and the adjacent groove
850.
Vertically journaled adjacent the supply roll 844 and spaced
forwardly therefrom in the manner indicated in FIG. 46 are a
plurality of glass-roving supply packages 854, the glass roving
supply packages 854 being spaced so that the glass strands
therefrom can be converged through a stationary guide ring 856
mounted adjacent the forward end of the mandrel 830 and so that the
strands, shown at 858, can be applied therefrom, in a desired
configuration, for example, in parallel relationship in accordance
with the horizontally elongated shape of the guide ring 856, onto
the previously wound layer of glass tape 846. The parallel strands
858 emerging from the guide ring 856 are preferably applied in the
same direction as the glass tape 846, and are thereby helically
wound onto the subjacent helically wound layer of glass tape 846 in
the manner illustrated in FIG. 46 responsive to the rotation of the
formed pipe, in a manner presently to be described.
Mounted forwardly adjacent the guide ring 856 and in any desired
location around the axis of the formed pipe are a plurality of
longitudinally arranged heaters 860 which may extend through any
desired length so as to apply heat to the pipe being fabricated
over a corresponding length of the pipe, which may, in some
instances, consist of one hundred feet or more of pipe length. The
initial heat supplied from the heating units 860 softens the
thermosetting resin of the glass tape 846 and allows the strands
858 to become embedded in the glass tape 846 to form a composite
laminar structure. The thermosetting resin is thereafter cured as
the pipe continues to advance past the heaters 860.
Glass tape 846 from supply rolls 844 and glass strands 858 from
roving packages 854 may be applied as many times as is necessary to
build up the finished pipe to the required wall thickness. The heat
which is applied to the superimposed material by the heaters 860
polymerizes the thermosetting resin. Depending on the rate of
production, the heat may be applied over any desired length of the
pipe being fabricated, for example, over a length of a hundred feet
or more.
Secured to the forward end of the tubular shaft 828 is a piston
assembly 861 comprising a main cylindrical disc member 862 which is
secured to the tubular shaft 828 by an axially extending fastening
bolt 864 as shown in FIG. 47, and clamps a resilient deformable
sealing cup 866 against an inner rigid washer 868. The sealing cup
866 is preferably made of polytetrafluoroethylene (Teflon), and
provides a seal in combination with the inside surface of the
formed pipe.
Connected to the forward end of the shafts 828, as by a rotary
sealing coupling 870, is a compressed air supply conduit 872 which
furnishes air under pressure through the sealed rotating connection
870 to the tubular shaft 828. The tubular shaft 828 is formed
adjacent the piston washer 868 with a discharge aperture 874
through which compressed air is discharged into the space 880
between the piston assembly 861 and the mandrel 830 and
substantially fills said space 880 also penetrating into the
circumferential space around the mandrel 830 to provide an air
cushion between the mandrel 830 and the inside surface of the pipe
formed thereon. The air pressure is equalized circumferentially
around the mandrel 830 by the provision of the equalizing grooves
848, 850, 852 so that channelling of the compressed air along the
peripheral surface of the mandrel is prevented, maintaining
substantially uniform air pressure around the periphery of the
mandrel and maintaining a substantially uniform air cushion between
the peripheral surface of the mandrel and the inside surface of the
formed pipe. The equalizing groove 848 communicates by means of
radial passages 876 with an annular end cavity 878 provided in the
mandrel 830, said cavity 878 being exposed to atmosphere, whereby
the air is allowed to bleed through the passages 876 and escape
freely so that air is not forced to flow out between the
unsupported cellophane and the forming mandrel 830. The air
pressure is such as to expand the pipe only to the amount required
to support the pipe properly while it is cured and to provide the
air cushion between the inside surface of the formed pipe and the
periphery of the forming mandrel 830, so as to allow the pulling
means D described above to move the pipe axially in a smooth and
efficient manner. Thus, as the pressure builds up in the space 880,
air leaks out between the forming mandrel 830 and the inside
surface of the formed pipe, allowing the air pressure to
automatically adjust to the desired value. Thus, the pipe floats
freely on the forming mandrel 830 because of the presence of the
aforementioned air cushion, sufficient air being fed into the pipe
to cause it to then expand circumferentially to a sufficient degree
to sustain the winding load imposed thereon from the glass roving
strands 854 and the glass tapes 846.
The pulling frame designated by the letter D in FIG. 46 is
identical in structure to the apparatus described above and shown
in FIG. 22. The pulling frame D is arranged coaxially with the
mandrel 830 and is spaced a substantial distance forwardly of the
heaters 860 and a short distance rearwardly of the piston assembly
861, as shown in FIG. 46. The tires 540 attached to the pulling
frame D extend inwardly and frictionally engage the periphery of a
cured pipe 882 extending from the mandrel 830. The rotation of the
pulling frame D, as described above, causes the tires 540 to engage
to cured pipe 882 and to pull the pipe 882 forwardly, while the
pipe 882 is simultaneously rotated by the pulling frame D.
In operation, the cellophane strips 842 are fed over the adhesive
coated cellophane tape strips 840 so that their side edges are
closely adjacent to each other to form a substantially air-tight
casing on the mandrel 830. The glass tape 846, impregnated with a
thermosetting resin, as above described, is fed from the roll 844
at an angle such as that illustrated in FIG. 46, being wound over
the cellophane strips 842 in a helical fashion between the annular
grooves 848 and 850 of the mandrel 830, as shown in FIG. 46. The
supply roll 844 is positioned so as to provide the desired pitch
angle for the wound glass tape 846. Similarly, the glass fiber
roving strands 858 are furnished from the roving packages 854 and
fed through the guide ring 856, in the manner above described, at a
location forwardly spaced from the glass tape 846, as shown in FIG.
46, being helically wound on the wound tape 846 and being applied
at a location spaced rearwardly from the groove 850 of the mandrel
and being located adjacent to or overlying the groove 852. Both the
glass tape 846 and the glass fiber roving strands 858 are fed under
adequate tension so as to provide a close wrap. As above mentioned,
the glass tape 846 and the roving strands 858 may be applied as
many times as is necessary to build up the finished pipe to the
required wall thickness. It will be understood that the winding of
the tape 846 and the glass fiber roving strands 858 takes place
because the cured pipe 882 is being rotated and simultaneously
pulled forwardly by the action of the pulling frame D above
described.
Heat is applied to the material by the heaters 860 to polymerize
the thermosetting resin, and the heat is applied over a length of
pipe forwardly of the mandrel 830, depending upon the rate of
production. As above mentioned, the heat may have to be applied, in
some cases, to over a hundred feet or more of pipe length.
The portion of the pipe between the mandrel 830 and the pulling
frame D is held in proper shape by the air pressure supplied to the
space 880 in the manner above described, the compressed air being
fed through the tubular shaft 828 and discharging in the space 880
through the aperture 874. The pressure is sufficiently high to
cause the pipe to expand circumferentially to sustain the winding
load imposed on the pipe by the roving strands 858 and the glass
tape 846, as above described, the expansion allowing the pipe to
float free of the forming mandrel 830, enabling the puller D to
move the pipe axially over the forming mandrel 830 and the piston
assembly 861 at the forward end of the shaft 828. As the pipe is
expanded, the air leaks out between the forming mandrel 830 and the
cellophane inner casing of the pipe, the air pressure being thus
automatically adjusted so that the pipe is expanded only to the
degree required to adequately reduce the friction between the inner
casing of the pipe and the forming mandrel, and so that the puller
D can easily move the pipe axially.
The pipe and puller assembly D are supported by sprocket chains 886
and 890, whereas the driving power is furnished by the electric
motor 892.
The tubular shaft 828 is preferably slidably adjustable relative to
the mandrel 830 to permit starting-up operation of the machine.
It will be noted that the apparatus illustrated in FIGS. 46 and 47
includes several important features from the standpoint of design
and operation. First, all glass and resin delivery systems are
fixed. This is a very important requirement for continuous
production machines, particularly for large diameter pipe. The only
revolving materials are the cellophane and adhesive coated
cellophane tape. Secondly, air pressure is used to balance the
winding tensions and to support the pipe over long lengths so that
the pipe may be passed unsupported through a long curing oven. This
will allow the pipe to be produced at a very high production rate.
The air pressure also reduces the friction between the cellophane
release layer and the forming mandrel 830. By using air pressure
there is no limit to the wall thickness to which the pipe can be
fabricated, since the more material that is applied, the more air
pressure can be furnished to balance same. Thirdly, the puller
assembly D operates on a fully cured section of the pipe which is
internally supported by air pressure. Thus, the puller is enabled
to simultaneously rotate the pipe and move it axially over the
forming mandrel 830 and through the curing oven.
Fourthly, a reinforced plastic pipe or tube may be fabricated with
a thick resin inner liner that would be in compression during
operating conditions. A resin coat would be applied to the
cellophane casing and cured by suitable heaters before the overwind
of glass tape and roving is applied. The mandrel at this point
would be reduced in diameter so that the overwind of glass tape and
roving would put the thick resin liner in compression. To present a
resin lining, the inner cellophane release layer, of course, would
have to be stripped from the pipe in a conventional manner. A
plastic pipe with a resin liner in compression can operate at much
higher stress levels and for longer periods of time than present
reinforced pipe.
It will be apparent that in devising the automatic, continuous
sytems for the manufacture of fiber reinforced plastic pipe
illustrated in FIGS. 1-47 above, a number of devices have been
included which possess utility for other purposes than as herein
before specifically described in connection with the manufacture of
fiber reinforced plastic pipe. The device G has general utility for
coating strip or sheet material. The belt system F may be used for
forming a resin tube apart from having the tube formed on such
system overwound with additional material or materials. The winding
head I and the manner of coating the continuous fiber elements
drawn off the head may be used for the application of bands or
layers of fiber elements to any hollow article of substantial
length, for example, the manufacture of a structural body which may
have a configuration other than cylindrical. Also, the control
device D may be used in processing any cylindrical member or pipe
such as metal pipe. The plug seal means C, while particularly
adapted for use in conjunction with a pipe assembly generated as
specifically described, is also useful where it may be desired to
process metal pipe by coating the same or otherwise treating the
continuously advanced pipe or tubing. The air piston E may be used
in conjunction with a rigid metal pipe or tube rather than in a
system which fabricates the pipe as described.
It is believed that the advantages and improved results afforded by
the invention will be apparent from the foregoing specifically
described preferred embodiments of the invention. It will be
apparent that various modifications and changes may be made without
departing from the spirit and scope of the invention as sought to
be defined in the claims which follow.
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