U.S. patent number 3,755,039 [Application Number 05/137,356] was granted by the patent office on 1973-08-28 for method of slitting and jacketing cylindrical bodies.
This patent grant is currently assigned to Johns-Manville Corporation. Invention is credited to Rupert Douglas Terry.
United States Patent |
3,755,039 |
Terry |
August 28, 1973 |
METHOD OF SLITTING AND JACKETING CYLINDRICAL BODIES
Abstract
Tubes are contacted by belts on the upper portion of their outer
surface to advance the tubes along a path paralleling their
longitudinal axes with the lower well being slit and a guide
subsequently being engaged to position the tube with its slot
paralleling an edge of a sheet of jacketing material advanced
toward the tube and positioned adjacent thereto whereby belts
acting normal to the path of the tubes contact the upper portion of
their outer surface to roll the tubes about their longitudinal axes
to engage the sheet jacketing material wrapping it about the tube
being rolled thereover.
Inventors: |
Terry; Rupert Douglas (Toledo,
OH) |
Assignee: |
Johns-Manville Corporation (New
York, NY)
|
Family
ID: |
22477043 |
Appl.
No.: |
05/137,356 |
Filed: |
April 26, 1971 |
Current U.S.
Class: |
156/187; 138/149;
156/259; 156/510; 156/212; 156/455 |
Current CPC
Class: |
B65H
81/06 (20130101); B31C 1/00 (20130101); B26D
3/001 (20130101); B29C 63/14 (20130101); F16L
59/023 (20130101); B26D 3/006 (20130101); Y10T
156/12 (20150115); Y10T 156/1028 (20150115); Y10T
156/1067 (20150115) |
Current International
Class: |
B65H
81/06 (20060101); B65H 81/00 (20060101); B29C
63/02 (20060101); B29C 63/14 (20060101); B31C
1/00 (20060101); F16L 59/02 (20060101); B26D
1/00 (20060101); B26D 3/00 (20060101); B31c
005/00 (); B65h 081/00 (); F16i 009/16 () |
Field of
Search: |
;156/184-185,187,191,192,259,256,443,446-447,455,510,513,218,457
;161/DIG.4 ;138/149 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Dier; Philip
Claims
I claim:
1. A method of jacketing cylindrical bodies comprising the steps
of:
advancing a tubular object from a supply source to a slitting
station;
advancing the tubular object in a direction parallel to its
longitudinal axis through the slitting station while maintaining
the tubular object in a fixed circumferential orientation;
slitting a wall of the tubular object parallel to the longitudinal
axis thereof while advancing the tubular object through the
slitting station to form a longitudinal slot in the tubular
object;
advancing the tubular object to a jacket application station while
maintaining the tubular object in the fixed circumferential
orientation by inserting guide means in the longitudinal slot;
advancing an adhesively coated jacketing material to the jacketing
station;
bringing a longitudinal edge portion of the jacketing material into
contact with the tubular object adjacent the longitudinal slot and
in parallel alignment with the longitudinal slot; and
rotating the tubular object about its longitudinal axis after
removing the guide means from the longitudinal slot to wrap the
jacketing material about the tubular object.
2. A method according to claim 1 wherein the adhesive on the
jacketing material is initially dormant and including applying an
activator fluid to the adhesive prior to bringing the jacketing
material into contact with the tubular object.
3. A method according to claim 2 including maintaining a second
longitudinal marginal edge portion of the jacketing material, that
is opposite the edge portion adjacent the longitudinal slot, free
of the activator fluid to keep the adhesive on the second
longitudinal marginal edge portion dormant.
4. A method according to claim 3 including maintaining the sheet of
jacketing material in a dwell position after the application of the
activator fluid and prior to contacting the tubular body with the
jacketing material to enable the adhesive to become tacky.
Description
BACKGROUND OF THE INVENTION
Heretofore jacketing has been applied to tubes of fibrous, thermal
insulation by manually wrapping the tubes with jacketing having
adhesive on the surface thereof adjacent the tube when the tube was
previously slit along its length.
One product resulting from the practice of the method and operation
of the apparatus of this invention is the subject of U.S. Pat.
application Ser. No. 003,638 filed Jan. 19, 1970, now abandoned for
"Self-Seal System for the Installation of Insulation" by John Paul
Mikulak which was filed prior to this application.
A method and apparatus for wrapping jacketing about unslit tubes of
insulation and subsequently slitting the wrapped tubes is the
subject of U.S. Pat. application Ser. No. 003,598 filed Jan. 19,
1970, now U.S. Pat. No. 3,695,965 for "Method and Apparatus for
Feeding and Wrapping Sheet Material" which was also filed prior to
this application.
With a previously slit tube, the jacketing material had to be
manually aligned with one edge of the material adjacent and
parallel to the slit prior to wrapping the jacket to properly align
the jacket to the tube. Subsequently, the tube was rolled across
the sheet so that the tacky adhesive on the surface of the
jacketing material caused the jacketing material to be picked up
and bonded to the tube. Manual operations of this nature are slower
than the time required for manufacture of smaller diameter tubes
which can be manufactured at rates approaching one every 4 to 5
seconds. As a result, the production of wrapped tubes is slowed
down by a time consuming manual operation and can only be achieved
by an increase in the amount of manual labor with accompanying high
labor costs and additional working area.
The present invention involves a method of and apparatus for
automatically slitting and jacketing cylindrical bodies at a rate
approximately the production rate of the cylindrical bodies with a
resultant reduction in labor, inhancement of material flow in a
plant, an increase in production speed and a reduction in
production cost as well as the required production area
required.
Sheets of jacketing material cut to suitable length for
encompassing cylindrical bodies and the cylindrical bodies are
indexed by indexing means at a first station to align an edge of
the sheet jacketing material with the longitudinal axis of the
cylindrical bodies. Means which can be in the form of dormant
adhesive on the surface of the sheet jacketing material and a spray
for activating the adhesive cause a portion of the outer peripheral
surface of the cylindrical bodies to adhesively contact the edge of
the sheet jacketing material. With the cylindrical bodies having
been slit and circumferentially oriented in advancing to the first
station, the cylindrical bodies are in proper alignment to be
rotated about their longitudinal axes to wrap the jacketing
material about the outer peripheral surface of the cylindrical.
Apparatus is provided to advance the sheets linearly from the stack
to a station in which the tacky surface is prepared and in one
embodiment to confine the region which is tacky to less than that
required to encompass the entire outer surface of the cylindrical
bodies. Also, apparatus is provided to advance the cylindrical body
linearly from a supply source to a station where it is slit, all
the while maintaining the circumferential orientation of the body
as it is advanced to alignment with the sheet material by use of
guide means which in one embodiment is a combination of a fixed and
retractable edge guide.
In one embodiment of the invention particularly applicable to pipe
insulation, the body and sheet material consist of a jacketed tube
having a region of jacketing which is not adhered to the tube to
expose a slot in the tube wall. The exposed slot affords a means of
slipping the jacketed tube over a pipe for insulation purposes. A
flap or tab of jacketing material having no tacky surface extends
loosely over the slot to provide a seal once the tube is placed
over a pipe by activation of the adhesive on the tab at that
time.
The above apparatus provides an automatic wrapping and slitting of
cylindrical bodies with sheet material aligned with the slot in the
body and, if desired, an extending tab which may later be used to
seal over the slot. The method developed for use with the machines
has resulted in an increase in production over previous manual
operations. The apparatus has eliminated the need for a manual
operation with the resulting savings in labor and work area
required.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary elevational view of a portion of a
manufacturing line including apparatus embodying the features of
the invention for automatically wrapping jacketing material on slit
tubes;
FIG. 2 is a fragmentary elevational view of a continuation of the
manufacturing line illustrated in FIG. 1;
FIG. 3 is a top view of the apparatus illustrated in FIG. 1;
FIG. 4 is a top view of the apparatus illustrated in FIG. 2;
FIG. 5 is a sectional view of the apparatus illustrated in FIG. 1
taken along line 5--5 thereof;
FIG. 6 is a right hand view of the apparatus illustrated in FIG.
2;
FIG. 7 is a sectional view of the apparatus illustrated in FIG. 2
taken along line 7--7 thereof;
FIG. 8 is a sectional view of the apparatus illustrated in FIG. 1
taken along line 8--8 thereof; and
FIG. 9 is an enlarged fragmentary sectional view of the apparatus
illustrated in FIG. 1 taken along line 9--9 thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present apparatus and method involves slitting and wrapping a
cylindrical body with a sheet of jacketing material adhered to a
portion or the entire outer surface of the body without an adhered
portion of the jacketing covering over the slot in the body. In the
preferred embodiment, the cylindrical body is formed of a tubular
mass of thermally insulating material to adapt it for pipe
insulation. The jacketing is formed of a sheet material which can
function as a vapor barrier for pipe insulation although flexible
sheet material having differing physical and chemical
characteristics may be applied by the techniques and apparatus to
be described.
Typically the cylinder to be jacketed is formed of a fibrous
insulating material which most commonly is formed of glass fibers
produced by passing molten glass through small orifices in pots
containing the molten glass to produce a plurality of glass
filaments. The filaments are subjected to hot gaseous blasts which
soften and attenuate them into small lengths of individual fine
fibers. The fibers are collected on a moving formation conveyor and
a binder, typically a thermosetting resin, is introduced into the
mat. The mat can be formed into cylinders by being cut into lengths
corresponding to the length of the total number of convolutions to
be employed in the cylinder and then wrapped around and compressed
upon a mandrel to form the cylinder having the desired inner and
outer diameter and density.
Alternatives to the above glass fibers, formed as described, can be
employed for thermally insulating tubes. These include other
materials which can be fiberized as by spinning, drawing,
attenuating and blowing into fine diameter fiber. Such material as
silicates of metal oxides, such as rock wools from argillaceous
matter or shale, slag wool from metallurgical slags, the commonly
known "mineral wools," aluminum silicate fibers and any fibers of
the so-called glasses can be formed into suitable cylinders.
The jacketing of flexible sheet material can be of various forms,
depending upon its intended function. In the example of thermal
insulation jacketing a composite sheet of an outer layer of paper,
an intermediate reinforcing web of glass fibers, and an inner layer
of aluminum foil is employed. The jacketing is coated on the metal
foil inner face with an adhesive, advantageously of the phenolic
neoprene type having the characteristics that it is inexpensive,
can be applied in controlled quantities, is dormant or not tacky,
is flexible, is non-flammable and is readily activated. A typical
activator for the adhesive is a suitable solvent such as
trichloroethane or methyl chloroform.
Jacketing sheets can be prepared from rolls of material, precoated
with adhesive conditioned to a non-tacky state, by cutting sheets
of jacketing of a length exceeding the circumferential length of a
cross section of the tube to be jacketed by an amount providing an
adequate sealing tab and a width substantially equal to the
longitudinal dimension of the tube. Such sheets can be employed
individually slthough automated jacketing is facilitated if they
are collected in stacks.
Referring to the drawings, FIGS. 1 through 4 illustrate one
embodiment of the invention in the form of a manufacturing line
wherein the major components consist of an inclined ramp 12 for
periodically feeding tubes 14 into a trough 16 where a forwarding
wheel 18 advances the tubes one at a time to a slitter station 20.
In passing through the slitter station 20, the tubes are cut
through the lower wall and partially on the inside of the upper
wall. A guide 53, illustrated in FIG. 9, in a transfer station 22
(see FIG. 1) maintains the orientation of the tube 14 as travel
continues on into a wrapping station 24. A retractable guide 182
(illustrated in FIG. 8) within the wrapping station 24 maintains
the orientation of the tube 14 until the tube 14 is engaged by a
swingable belt conveyor 26 capable of being lowered upon the tube
14. At the same time, the retractable guide 182 is caused to be
lowered downwardly away from the tube 14 to enable rolling of the
tube 14 to occur when the conveyor 26 contacts the outer peripheral
surface of the tube 14.
Simultaneous with the advance of the tube 14 to the wrapping
station 24 is the movement of the jacketing 28, made of sheet
material, from a stacking station 30 in a direction opposite to
that of the movement of the tubes 14 (see FIGS. 2 and 4).
Individual sheets of jacketing 28 are advanced and the adhesive on
the upper face is activated at a pickup-spray station 32. The
jacketing 28 is advanced to a jacketing conveyor 34 which spans
both the wrapping station 24 and the pickup-spray station 32. The
jacketing conveyor 34 carries the individual sheets of jacketing 28
through a dwell portion between the wrapping and pickup-spray
stations 24 and 32 and on into the wrapping station 24. The dwell
portion gives the previously sprayed activator on the sheet time to
activate the adhesive which as a result becomes tacky. Upon
entering the wrapping station 24, one edge of the sheet of
jacketing 28 is aligned adjacent and parallel to the slot formed in
the tube 14, and opposing edges of the sheet align with respective
ends of the tube 14. When the tube 14 is rolled over the sheet of
jacketing 28, as described above, the tacky surface causes the
jacketing 28 to wrap around the tube 14 in alignment with the slot
in the tube 14 and the ends thereof.
From the above overall description of the line, it is apparent that
work flow to the line originates at both ends thereof and moves
toward the wrapping station 24 which discharges work by a motion
transverse to that of the line. In describing the above line, it
will be advantageous to describe the components associated with
each of the three work flows separate from the rest of the
line.
First, consider the work flow with respect to the tubes 14 which
involves the components of the inclined ramp 12, trough 16,
forwarding wheel 18, slitter station 20 and transfer station 22.
These components are illustrated in FIGS. 1 and 3. The inclined
ramp 12 is additionally illustrated in FIG. 5 and consists
basically of a pair of structural angles 36 suitably framed with
structural steel base 42. It will be noted that the base 42 extends
over the entire line to support all the components as well as the
inclined ramp 12. The inner legs of the angles 36 oppose each other
while the other legs form side guides for the tubes 14 resting
between them on the inner legs. The ramp 12 is inclined to the
horizontal to encourage the tubes 14 thereon to roll toward a
feeder bar 38. Fingers 40 on the feeder bar 38 located near the
extremities of the length of the bar 38 are spaced radially at
90.degree. intervals around the bar 38. Each time the bar 38 is
rotated 90.degree., a finger 40 at each end of the bar 38 engages
the tube 14 adjacent it and flips it over the bar 38 into the
trough 16. Energization of the feeder bar 38 is accomplished by an
air cylinder 41 connected to a rack and pinion box combination 43.
The bar 38 is pivotally mounted in pillow block bearings 45 on the
base 42. To guide the tubes 14 into the trough 16, a retainer bar
39 is provided which extends over the inclined ramp 12.
Clearly, other means of supplying the line could be employed such
as means for vertically stacking the tubes 14 above the trough 16
for release one by one. In like sense, the inclined ramp 12 could
be hydraulically actuated with respect to the feeder bar 38 and the
bar 38 itself could be replaced also, for example, by an orifice
and gate.
Located adjacent the inclined ramp 12, the trough 16 is of "V"
shape to receive the tubes 14 fed from the ramp 12. Support for the
trough 16 is achieved by a structural tie to the inclined ramp 12.
In between the trough 16 and the slitter station 20, a forwarding
wheel 18 is rotatably mounted and continuously driven by a
motor-reducer 44 through a chain and sprocket set 46. A similar "V"
shaped open trough 48 extends from the slitter station 20 toward
the forwarding wheel 18 and is aligned with the trough 16 being, in
effect, a continuation of trough 16. The open trough 48, unlike
trough 16, does not have an apex at the bottom so that the tubes 14
therein are exposed for slitting purposes. The overhang of the open
trough 48 and trough 16 span the face of the inclined ramp 12 to
give support over the full length of each tube 14 deposited into
the troughs 16 and 48. With the forwarding wheel 18 located
intermediate of the two troughs 16 and 48, a vertical height
alignment of the upper periphery of the forwarding wheel 18
slightly above the rest position of the bottom of a tube 14 within
the troughs 16 and 48 allows the tube 14 to be driven by the
forwarding wheel 18. When a tube 14 is released from the inclined
ramp 12 into the troughs 14 and 48, it is immediately advanced by
the continuously running forwarding wheel 18 to the entry end of
the slitter station 20. If the slitter station 20 is not in a
condition to accept a tube 14, the tube 14 will be stopped at the
entry to the slitter station 20 and the forwarding wheel 18, which
continues to run, is allowed to slip beneath the tube 14 thereby
maintaining the tube 14 against the entry of the slitter.
Apparatus in the form of troughs 16 and 48 plus a forwarding wheel
18 have been described as illustrated in the drawings of the
preferred embodiment but other means could be used to advance the
tubes released from the inclined ramp 12 to the entry of the
slitter station 20. One example of an alternative is a driven set
of rollers in place of the troughs 16 and 48 and wheel 18.
Basic components of the slitter station 20 are the open trough 48
which continues over the length of the station 20, the slitter saw
50, the pressure belt 52 and fixed guide 53. The saw 50 includes a
continuously rotating circular blade 54, which may or may not have
teeth, and of sufficient diameter to pass through the bottom wall
of a tube 14 and a portion of the inner wall of the tube
diametrically opposed to the slit. The blade 54 is positioned
between the opening in the open trough 48 to engage tubes 14
passing thereover. A suitable bearing mounting 56 for the blade 54
is attached to the base 42 and a motor 54 is used to drive it
through a belt and sheave combination 60. To positively orient and
advance a tube 14 through the slitter station 20 a pressure belt 52
is driven counter clockwise as viewed in FIG. 1. Engagement of the
tube 14 and belt 52 occur at the top surface of the tube 14. A high
coefficient of friction of the belt surface contacting the tube 14
prevents slippage between the tube 14 and the belt 52. Further, the
clearance between the belt 52 and open trough 48 is slightly less
than that required by the O.D. of the tube 14 so that engagement
between the belt 52 and tube 14 causes compression of the tube 14,
within its elastic limits, thereby pressing the tube 14 against the
belt 52 for firm contact. Movement of the belt 52 and, therefore,
advancement of the tube 14 is caused by rotation of drive pulleys
62 and 64 and an associated idler pulley 66 over which the belt 52
passes in forming a continuous loop. Mounted on the base 42 is a
motor-reducer 68 for driving the drive pulley 62 through a chain
and sprocket combination 70. On the rotatable shaft 72 supporting
the drive pulley 62 a magnetic clutch 74 is mounted for selectively
engaging and disengaging the pulley 62 from the continuously
running motor-reducer 68 to stop and start the pressure belt 52.
Drive pulley 64 is driven by the interconnecting chain and sprocket
loop 76. Adjustment of tension on the pressure belt can be
accomplished by either adjusting the idler pulley 66 within its
takeup block 78 or by tension pulley 80 or both. A tension sprocket
82 is placed on chain loop 76 to maintain tension on the loop 76.
To guide the tubes 14 and retain their proper circumferential
orientation through the slitter station 20, a guide 53, illustrated
in FIG. 9, in the form of a strip of metal centered with a
longitudinal edge pointing upward within the opening of the open
trough 48 extends up into the trough 48 downstream of the slitter
saw 50 to engage the tubes 14 by entering the slot formed therein
by the saw 50.
The guide 53 within open trough 48 continues over the length of the
transfer station 22 as does the trough 48. Support for both trough
48 and guide 53 as well as the transfer belt 84, is provided by the
base 42. The transfer belt 84 duplicates the pressure belt 52 in
operation and serves as a feed mechanism for the wrapping station
24. Since the transfer belt 84 has a smaller loop than the pressure
belt 52, the supporting components are less elaborate having simply
one drive pulley 86 and two idler pulleys 88 and 90. The drive
pulley 86 is connected to motor-reducer 92. Both the transfer belt
84 and pressure belt 52 are cycled together to start and stop at
the same time thereby providing a smooth advance of the tubes 14
through each station 20 and 22. The firm contact between the tubes
14 and transfer belt 84 along with the guide 53 in trough 48
combine to deliver the tubes 14 in proper alignment to the wrapping
station 24.
Attention will now be turned to those components for the transfer
of jacketing 28 to the wrapping station 24, namely, the stacking
station 30, pickup-spray station 32 and jacketing conveyor 34
illustrated in FIGS. 2 and 4.
The jacketing 28, in the form of sheet material precut to size and
having non-tacky adhesive on one major surface thereof, is stacked
with the adhesive facing upward on the stacking station 30. A flat
metal plate 94 having fixedly attached side guards 96 is pivotally
connected, as at 98, to the base 42 to form a swingable stacking
station 30 as illustrated in FIGS. 2, 4 and 6. An air cylinder 100
is pivotally connected to the base 42 beneath plate 94 and to the
plate 94 by a cylinder rod clevis 102. Energization of the cylinder
100 raises the end of the stack of jacketing 28 adjacent the
jacketing conveyor 34 to enable the vacuum cups 104 of the
pickup-spray station 32 to engage the top sheet of jacketing 28 on
the stack.
To enable the vacuum cups 104 of the pickup-spray station 32 to
advance the top sheet of jacketing 28 onto the jacketing conveyor
34, both the cups 104, illustrated in FIG. 2, and the non-flexible
vacuum tubes 106 are attached to an air cylinder 108 through a
mounting 110 pivotally attached to plates 111 on a structural
bridge 112 including spaced apart vertically extending columns 114
and an interconnecting angle 116 which in turn are supported by the
base 42. The cylinder 108 has its base pivotally mounted to an
angle 116 so that as the cylinder rod 118 moves in and out, the
vacuum cups 104 are swung in an arc spanning the end of the
jacketing conveyor 34 and the stacking station 30. Pickup and
release of the jacketing 28 by the cups 104 is accomplished through
activation and deactivation of the vacuum on the cups 104 furnished
by a vacuum pump 120. Freedom of motion for swinging of the cups
104 is enhanced by the flexible vacuum line 122 interconnecting the
pump 120 and the vacuum tubes 106.
Mounted on the structural bridge 112 on the opposite side from the
vacuum cups 104 is a spray system, illustrated in FIG. 7 as well as
FIGS. 2 and 4, capable of applying activator fluid to the adhesive
coated on the upper face of the jacketing 28 passing thereunder.
Accuracy of the spray is governed by the flat spray type nozzle 124
and must be capable of maintaining one longitudinal marginal edge
of the surface of the jacketing 28 dry while thoroughly wetting the
opposite marginal edge. Control of the amount and dispersion of the
activator fluid is accomplished through use of a constant head of
activator fluid pressure on the nozzle 124. Pressure of a low
range, for example, 5 pounds gauge, is sufficient because of the
accuracy of the nozzle orifice through which the fluid passes.
Supply of activator fluid to the nozzle is provided by a line 128
from an associated constant pressure source, not illustrated. Use
of a spray nozzle 124 assures a dry margin on the edge of the
jacketing 28 opposite that being sprayed to produce the tab 132,
illustrated in FIG. 4, on the finished product when the jacketing
is wrapped on the tubes 14.
Clearly, there are alternative apparatus for the pickup-spray
station 32; for example, the activator could be brushed or rolled
into the jacketing 28 and the jacketing 28 could be pulled from a
stationary stack by an overhead rotating friction contact or the
like. Further, adhesive could be applied to the jacketing 28
instead of activator, and while bonding between the jacketing 28
and tube 14 is enhanced by adhesive over the entire face of the
jacket, exclusive of the tab 132, it is sufficient if only the edge
opposite the tab 132 and the area immediately adjacent the tab 132
have adhesive to produce the wrapped tube product. At least one
third the periphery of the tube 14 to be covered should be bonded
to the jacketing 28 with adhesive.
Overlapping the pickup-spray station 32 and the wrapping station 24
is a jacketing conveyor 34 illustrated in FIGS. 1 through 4, and 8.
Three conveyor type belts 134 wrapped in a continuous loop around
drive drum 136 and idlers 138 and 140 in conjunction with three
similar but shorter conveyor type belts 142 forming a continuous
loop about drive drum 144 and idlers 146 and 148 form the jacketing
conveyor 34. All of the drums 136, 138, 140, 144, 146 and 148 are
rotatably mounted having stub shafts in pillow block bearings
supported by the base 42. Conveying of the jacketing 28 from the
stacking station 30 is aided by a plenum 150 beneath the shorter
belt 142 portion of the jacketing conveyor 34. A negative pressure
within the plenum 150 draws the jacketing to the belts 142 upon
release by the vacuum cups 104. The plenum 150 is typically
connected to a negative pressure source (not illustrated) by a
flexible hose 152.
Travel of jacketing 28 on the jacketing conveyor 34 is accomplished
in steps with the leading end of the jacketing energizing a photo
cell 154 to stop the conveyor 34 when a jacketing sheet 154 has
reached the position illustrated in FIG. 4 downstream of the
pickup-spray station. Reactivation of the conveyor 34 occurs when
the previous tube 14 has cleared the wrapping station 24 resulting
in a start stop operation. The position illustrated by jacketing
sheet 156 is a dwell position which furnishes sufficient time for
activation of the adhesive on the sheet 156, resulting from wetting
by the activator fluid, to cause the adhesive to become tacky. When
a subsequent sheet is advanced to the dwell position and stopped by
the photo cell 154, the sheet formerly in the dwell position is
advanced into the wrapping station 24 and stopped. Splitting the
jacketing conveyor into two loops consisting of the long belts 134
and the short belts 142 results in an independent loop consisting
of short belts 142 serving the pickup and spray station.
Preferably, the short belts 142 are run at a constant speed which
is coordinated with the spray of activator fluid, also an
established constant, to cause a constant volume of activator fluid
to be deposited per unit area of adhesive coated jacketing 28
wetted. Further, greater flexibility is available in that the speed
of the longer belts 134 can be varied independently of the speed of
the shorter belts 142.
Adjustment of tension on the jacketing conveyor 34 is enhanced by
the idler drums 140 on the belts 134 and 142, respectively, which
allow the belts 134 and 142 to be tensioned without moving the
drums 136, 138, 144 and 148 aligned with the line equipment and
having spaced relations thereto. Energization of the longer belts
134 is provided by a motor 158, illustrated in FIG. 1, connected to
drive drum 136 through a magnetic clutch brake combination 160
driving a reducer 162 connected to a chain and sprocket loop 164.
The above drive components are fixedly secured to the base 42. The
magnetic clutch-brake 160 allows the conveyor to be stopped with
accuracy while the motor 158 continues to run.
Driving the short belts 142 is a motor-reducer acting through a
chain and sprocket loop 165 on drive drum 144 as illustrated in
FIG. 2.
As pointed out above, adhesive could be applied to the sheets at
the spray station 32 instead of activator fluid thereby also
altering the jacketing conveyor 34 by eliminating the dwell
portion. Also, other means of conveying the jackets into the
wrapping machine could be used; for example, a roller hearth could
be used in place of a conveyor.
Having described the apparatus illustrated for handling the flow of
the tubes 14 and the jacketing 28, attention will now be turned to
the wrapping station 24 where the tubes 14 and the jacketing 28 are
assembled The wrapping station 24 is illustrated in FIGS. 1, 3 and
8 and includes a swingable belt conveyor 26 having a series of flat
belts 166 wrapping a drive roll 168 and an idler roll 170 in
continuous loops. Both rolls 168 and 170 are journaled to a box
frame structure 172, which, in turn, is pivotally connected to the
base 42 as at 174. The base 42 also supports spaced apart
vertically extending columns 176. A bracket 178 is supported by
cross ties 177 (see FIG. 8) spanning the columns 176. Pivotally
suspended from the bracket 178 is an air cylinder 180. The rod end
of the cylinder 180 is pivotally connected to the box frame 172 at
the end opposite the pivoted connections 174 to enable the
swingable belt conveyor 26 to swing about the connections 174 as
the cylinder 180 is operated. With the cylinder 180 in a position
where the cylinder rod 181 is extended, FIG. 8 illustrates that the
conveyor 26 contacts the outer peripheral surface of the tube 14.
When the cylinder rod 181 is retracted, the conveyor 26 is swung
clear to allow the tube 14 to enter the wrapping station 24. Proper
orientation of the tube 14 is maintained by retractable guide 182
which engages the slot in the tube 14 upon its entering the
wrapping station 24. Upon contact of the entering tube 14 with a
flag 184, a limit switch, not illustrated, is activated causing an
air cylinder 186 to which the retractable guide 182 is affixed to
retract the guide 182 beneath the bed 188 of the wrapping station
24. At the same time, cylinder 180 is extended to allow the
swingable conveyor 26 to engage the tube 14 which is free to roll
under the frictional contact between it and the moving belts 186.
The bed 188 provides rigid support for both the jacketing conveyor
belts 134 passing thereover and the jacketing 28 on the belts 134.
Indirectly, the bed 188 also provides support for the tube 14 as it
rolls over the jacketing 28. With the tube 14 supported as
described above, pressure can be exerted on the tube 14 by the
swingable conveyor 26. Application of pressure as the tube 14 is
rolled prevents slippage between the tube and conveyor 26 to assure
that the alignment of the edge of the jacketing 28 with the slot in
the tube 14 is maintained. Further assurance that the tube 14 is
rolled over the entire surface of the jacketing 28 is provided by
preventing slippage between the tube 14 and conveyor 26. Since the
upper surface of the jacketing 28 is tacky upon entering the
wrapping station 24, the jacketing 28 is picked up by the tube 14
as it rolls. After a half revolution of the tube 14, the jacketing
28 on the tube 14 is engaged by the swingable conveyor 26 to
complete a full revolution of the tube 14 thereby completing the
wrapping process. The tubes 14 are discharged in sequence with each
subsequent tube 14 pushing the prior tube 14 from the end of the
swingable conveyor 26 to be removed or dropped from the bed 188 to
a collector. Movement of the swingable conveyor belts 166 is
provided by a motor-reducer 190 supported by the columns 176
operating through a chain and sprocket loop 192 to drive the drive
roll 168.
Other means of energization are available in place of a
motor-reducer 190 and cylinders 180 and 186 such as a hydraulic
motor and rack and pinion drive, respectively.
The method of operation of the above apparatus is to coordinate the
simultaneous flow of the tubes 14 with the flow of the jacketing 28
to bring them together for assembly in the wrapping station 24.
Assuming the line is in continuous operation, a sheet of jacketing
28 will be positioned at the dwell portion of the jacketing
conveyor 34 and the inclined ramp 12 will have the tubes 14 stored
thereon. Upon a predetermined signal, a tube 14 is released from
the inclined ramp 12 and deposited in the trough 16 and 48 (see
FIGS. 1 and 3). Immediately, the tube 14 is advanced to the entry
of the slitter station 20 by the continuously rotating forwarding
wheel 18 where the leading edge of the tube 14 abuts the stationary
pressure belt 52 of the slitter station 20. The pressure belts 52
and 84 of the slitter and transfer stations 20 and 22 are activated
in unison by a top limit switch, not illustrated, which is
contacted by the swingable conveyor 26 when the conveyor 26 reaches
its top position to provide clearance for a tube 14 to advance
therebeneath. Advancement of the jacketing 28 from the dwell
position by the jacketing conveyor 34 requires that the area into
which the sheet is to be advanced be clear as indicated by the
passing of a tube 14 over the prior sheet of jacketing 28 by
contacting an end limit switch, not illustrated, at the discharge
of the wrapping station 24. Activation of the jacketing conveyor 34
is accomplished by the end limit switch to assure that the
receiving area is clear for the jacketing 28 being advanced.
Energization of the jacketing conveyor 34 is the last step in a
sequence of motions which precede it to advance the jacketing 28 to
the dwell position. Thus, each time the end limit switch is
contacted by a tube 14 each step in the sequence is activated.
Viewing the steps starting with stacking station 30 in the order in
which they occur, FIGS. 2 and 4 illustrate the vacuum cups 104
positioned over the jacketing conveyor 34 from which position they
swing over the stack of jacketing 28 on the stacking station 30.
With the vacuum cups 104 activated, the stacking station 30 is
elevated to meet the cups 104 with the top sheet of jacketing 28
being engaged by the cups 104 which have a vacuum drawn thereon.
Next, the vacuum cups 104 are positioned over the jacketing
conveyor 34 while the stacking station 30 is lowered, and the cups
104 are deactivated to release the sheet of jacketing 28 whose
leading end falls onto the jacketing conveyor 34. Sufficient
contact between the leading end of the jacketing 28 to carry the
remainder of the sheet of jacketing 28 onto the conveyor 34, is
supplied by the plenum 150 which has a negative pressure therein to
draw the sheet of jacketing down against the jacketing conveyor 34.
As the jacketing 28 is advanced by the jacketing conveyor 34, it
passes the nozzle 124 of the pickup-spray station 32. A patterned
flow from the nozzle sprays activator fluid on the upper face of
the jacketing 28 to activate the adhesive thereon over the marginal
edge of sheet 156 of FIG. 4 opposite the tab 132. As an
alternative, the entire face with the exception of the tab 132 can
be sprayed or the above marginal edge and one adjacent the tab 132
can be sprayed. The marginal edge is maintained free of activator
by the accuracy of the nozzle to create a non tacky tab 132 on the
jacketing sheet 156 which overlaps the slot in the tube 14 when the
jacketing 28 is wrapped around it. From the pickup-spray station
32, the jacketing 28 is advanced to the dwell portion of the
jacketing conveyor 34 where the leading edge of the jacketing sheet
156 energizes the photo cell 154 stopping the jacketing conveyor 34
and deactivating the spray nozzle 124. A sequence of steps has now
resulted in a return to the jacketing 28 positioned in the dwell
portion of the jacketing conveyor 34. With the top limit switch
contacted by the swingable conveyor 26 of the wrapping station 24,
the switch activates the slitter and transfer stations 20 and 22 to
advance the tube 14 being held against the entry of the slitter
station 20 on into the wrapping station 24. As the tube 14 is
advanced through the slitter station 20 the saw 50 cuts a slot
through bottom wall of the tube 14 and partially through the
diametrically opposed inner wall. The tube is advanced through the
saw 50 and the transfer station 22 by pressure belts 52 and 84,
respectively, with the slot being engaged by a guide 53 subsequent
to the saw 50, until being released from the transfer station 22.
As the tube 14 is advanced to the wrapping station 24, the sheet
156 of jacketing 28 is advanced from the dwell portion of the
jacketing conveyor 34. Stoppage of the jacketing conveyor 34 by a
subsequent sheet 156 of jacketing entering the dwell portion
thereof stops and aligns the sheet 156 of jacketing 28 which has
entered the wrapping station 24 so that the ends of the sheet 156
and the ends of the tube 14 are adjacent each other. Location of
the tube 14 advancing into the wrapping station 24 is provided by
contacting the flag 184. The tube 14 must advance to trip the flag
184 activating the flat limit switch (not shown) to cause the
lowering of both the swingable belt conveyor 26 and retractable
guide 182. The retractable guide 182 maintains the circumferential
orientation of the tube 14 as it leaves the guide 53 which is
within the transfer station 22 and aids in guiding the alignment of
the jacketing 28. Retraction of the guide 182, therefore, leaves
the tube free to roll under the contact of the moving belts 166 of
the swingable conveyor 26. With both tube 14 and jacketing 28
having been aligned within the wrapping station 24, rolling of the
tube 14 over the tacky surface of the jacketing 28 results in the
jacketing 28 being wrapped about the tube 14 with the longitudinal
edge of the jacketing 28 adjacent the tube 14 slot mating with the
edge of the slot. The operation ends with the tubes 14 wrapped with
jacketing 28 being discharged to the bed 188 of the wrapping
station 24 and the swingable conveyor 26 and retractable guide 182
being returned to their raised positions upon the discharged tube
contacting the end limit switch.
While the above method has been described with respect to the
preferred embodiment it is to be understood that the method of
indexing the tubes and sheet material and the steps of aligning and
wrapping the tubes could be performed other than on the present
apparatus and even manually with the aid of guiding means.
The precut size of the jacketing 28 and the width of the tab 132
left unactivated determine the overlap of jacketing to provide a
readily activated adhesive tab 132 for sealing the slot of the
finished product. If no excess is provided and the entire surface
of the jacketing is wetted then the tube is covered without a tab
132 leaving the slot exposed unless an independent seal is later
applied. The above apparatus is applicable to either concept.
Advantages of the above apparatus and method include a faster rate
of production of wrapped tubes over previous manual wrapping with
the wrapping process capable of matching the rate of production of
tubes to eliminate a production bottle neck. The elimination of
manual labor results in a reduction in labor cost as well as a
savings in work area required.
In accordance with the provisions of the patent statutes, the
principle and mode of operation of the machine have been explained
and what is considered to represent its best embodiment has been
illustrated and described. It should, however, be understood that
the invention may be practiced otherwise than as specifically
illustrated and described without departing from its spirit or
scope.
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