U.S. patent number 3,707,170 [Application Number 05/052,295] was granted by the patent office on 1972-12-26 for method of making a tubular member by helically coiling a metallic strip, tubular member produced by this method and device for carrying out this method.
This patent grant is currently assigned to Societe Anonyme Des Hauts Fourneaux De La Chiers. Invention is credited to Daniel E. Hoffmann, Rene A. Mazuir.
United States Patent |
3,707,170 |
Mazuir , et al. |
December 26, 1972 |
METHOD OF MAKING A TUBULAR MEMBER BY HELICALLY COILING A METALLIC
STRIP, TUBULAR MEMBER PRODUCED BY THIS METHOD AND DEVICE FOR
CARRYING OUT THIS METHOD
Abstract
A strip having hooked edges is laterally curved and coiled into
a spiral in which the hooked edges of adjacent coils overlap. Just
before the coils are overlapped the strip is formed into a helix
the turns of which slant in a direction opposite to that of the
turns of the helix finally formed so that when adjacent turns are
forced into engagement with each other adjacent turns are
resiliently biassed toward each other. The invention includes
apparatus adapted to carry out this method and the tubular member
produced thereby.
Inventors: |
Mazuir; Rene A.
(Bourg-en-Bresse, FR), Hoffmann; Daniel E.
(Bourg-en-Bresse, FR) |
Assignee: |
Societe Anonyme Des Hauts Fourneaux
De La Chiers (Longwy-Bas, FR)
|
Family
ID: |
9037270 |
Appl.
No.: |
05/052,295 |
Filed: |
July 6, 1970 |
Current U.S.
Class: |
138/154; 72/49;
138/178; 52/108; 138/134 |
Current CPC
Class: |
F16L
11/16 (20130101); B65H 81/08 (20130101); B21C
37/124 (20130101); B29C 69/008 (20130101); B21C
37/121 (20130101); B29C 63/343 (20130101) |
Current International
Class: |
B65H
81/00 (20060101); B29C 63/34 (20060101); B29C
69/00 (20060101); B21C 37/06 (20060101); B21C
37/12 (20060101); B65H 81/08 (20060101); F16L
11/00 (20060101); F16L 11/16 (20060101); F16l
009/16 (); B21c 037/12 () |
Field of
Search: |
;72/49,50 ;29/458,505
;138/129,131,133,134,135,136,154 ;52/108 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lanham; Charles W.
Assistant Examiner: Rogers; R. M.
Claims
What is claimed is:
1. Method of manufacturing a flexible tubular member by coiling a
metallic strip having longitudinally extending abutment means into
a helix having overlapping turns, which method comprises the steps
of imparting an arcuate deformation to said strip such that the
edge of said strip which is to be on the outside of the overlapping
turns in the completed tubular member is longer than the edge of
the strip which is to be on the inside thereof, coiling said strip
into a helix in which, when said helix is a axially unstressed, the
turn last formed lies on one side of the preceding turn, and
stressing said strip by positioning the last-formed turn on the
other side of said preceding turn, with the portion of the of the
longitudinal abutment means in each turn contacting a surface on an
adjacent turn to resist a return of said strip to its unstressed
position.
2. Method as claimed in claim 1 in which, when said helix is
axially unstressed, the shorter edge of the section of said strip
defining said last-formed turn lies close to the longer edge of the
section of said strip defining the preceding turn, and the longer
edge of the strip defining said last-formed turn is adjacent the
shorter edge of the section of said strip defining said preceding
turn when said helix is axially stressed.
3. Method as claimed in claim 1 in which the edges of said strip
are hooked in opposite directions and the adjacent edges of
adjacent turns are hooked over each other to resist separation of
said turns axially of said tubular member.
4. Method as claimed in claim 1 according to which said strip is
made of strong steel.
5. Method as claimed in claim 1 according to which the tubular
member is formed about a plastic tube.
6. Flexible tubular member in the form of a helical coil having
overlapping turns made from an arcuate metal strip, one edge of
which is longer than the other, said strip comprising
longitudinally extending abutment means, and being under an
internal tension biassing the shorter edge of each turn of said
coil toward the adjacent longer edge of an adjacent turn until the
abutment means of each turn engages a cooperating surface on an
adjacent turn with a force sufficient to cause said turns to
reverse their relative positions axially of said coil if said
reversal were not prevented by said engagement.
7. A tubular member as claimed in claim 6 encircling a fluid-tight
tube and adapted for use in drilling oil wells.
8. Device for forming a flexible tubular member from a metallic
strip of material having longitudinally extending abutment means
which comprises in combination, means for leading the strip along a
plane substantially parallel to the axis of the tubular member
which is to be formed, means for imparting a permanent arcuate
deformation to said strip such that the edge of the strip in the
direction in which the tubular member is being formed is longer
than the other edge of the strip, means for imparting a helical
deformation to said strip to form it into a helix having a diameter
substantially equal to that of the member being formed, and for
engaging the longer edge of the turn being formed with the turn
which has just been formed, means for guiding the tubular member
thus formed, and means for synchronizing the speed of rotation of
the tubular member being formed and the feed of the strip from
which the member is to be formed.
9. Device as claimed in claim 8 in which the means for imparting an
arcuate deformation to the strip comprises a set of rollers which
bends said strip beyond its elastic limit.
10. Device as claimed in claim 8 in which the means for forming the
strip into a helix comprises a forming head including a plate
mounted on a universal joint so that its position m be adjusted
about both a horizontal and a vertical axis.
11. Device as claimed in claim 10 in which the plate comprises a
central orifice through which the tubular member is being formed
and that the forming fingers are positioned on the periphery of
this orifice by supports which are angularly and longitudinally
adjustable.
12. Flexible tubular member as claimed in claim 6 in which the
edges of said strip are hooked in opposite directions and the
adjacent edges of adjacent turns are hooked over each other to
resist separation of said turns axially of said tubular member.
13. Device as claimed in claim 8 in which said means for imparting
an arcuate deformation to said strip imparts said arcuate
deformation in a plane passing through both edges of the strip.
Description
SUMMARY OF THE INVENTION
This invention relates to a new method of manufacturing tubular
articles by helically winding a shaped metallic strip, to the new
tubular members produced by this method, and to the apparatus used
in carrying out said method.
It is the object of the present invention to provide tubular
members made by the simple interfitting of shaped metallic strips
and which have the characteristic of possessing both great
mechanical strength and a substantial flexibility so that the
tubular members may be wound up on cores of relatively small
diameter.
The tubular members according to the invention may be
advantageously used as flexible drill pipe in the drilling of oil
wells.
When flexible drill pipe is used for this purpose a bit is mounted
at the end of a long tubular member having a certain flexibility,
and driven either by an electrical motor at the head of the well,
and supplied through electrical cables passing down through the
tubular member, or by a turbine driven by a fluid such as the mud
which is forced under pressure into the flexible tubular
member.
The great advantage presented by this new drilling process resides
in the fact that it is unnecessary to rotate the tubular member
about its axis as it is progressively introduced into the ground,
as is the case in conventional drilling methods.
Moreover, the fact that the tubular member is flexible makes it
possible to roll it up easily on drums of relatively small
diameter. This considerably facilitates the operations of sending
down and withdrawing tubular members which are always necessary for
the maintenance and repair of drilling bits.
The cylindrical members used for flexible drilling generally
comprise an internal tube of plastic material which seals the
tubular member against fluids which pass therethrough and provides
a smooth inner surface which facilitates the flow of fluids. This
internal tube must be located inside an equally flexible tubular
member which is capable of resisting the substantial mechanical
stresses resulting from the high pressures which must prevail
inside and outside the tubular member during drilling. This
flexible tubular member may be made, in accordance with the
invention, from a helically coiled shaped metallic strip.
The tubular members according to the invention are then, in the
case of flexible drilling tubes, covered by layers of wire wound
thereabout, as in the case of cables, to insure the mechanical
strength and resistance to tension which are required.
The present invention proposes to provide tubular members which,
while sufficiently flexible, have a substantial mechanical strength
so as to be capable of resisting both internal and external
pressure. Moreover, the tubular bodies according to the invention
may be easily formed directly around the tube which is to
constitute a fluid-tight seal.
The manufacture of tubular members of the type according to the
invention from strong shaped steel strips has already been
suggested, using strips having the general form of a Z or an S.
However, it has not heretofore been possible to helically wind such
shaped strips under satisfactory conditions.
It has been found, in effect, that when an attempt is made to
helically wind a strip having an S or Z section by conventional
methods the cohesion between the turns of the resulting tubular
member is insufficient. This results in poor mechanical strength,
which renders such a tubular member completely unsuitable for use
as flexible drilling pipe.
It is the object of the present invention to provide a new process
for manufacturing a flexible tubular member adapted to be used as
flexible drilling pipe from a strong shaped steel strip having an S
or Z section. In accordance with this method a permanent arcuate
deformation is imparted to the strip, so that the edge of the strip
which, after manufacture of the tubular member, is outside the
tubular member, is longer than the edge of the strip which, after
manufacture of the tubular member, is inside thereof. After having
first deformed the metallic strip in this manner, it is helically
deformed to form the tubular member by engaging one edge of the
strip over the edge of the last-formed turn of the tubular member.
This process is characterized by the fact that the strip is given a
shape such that it is resiliently biassed against the last-formed
turn of the tubular member.
For this purpose the shaped strip is given a natural helical shape
in a direction opposite to that in which the tubular member is
being formed.
The present invention is also directed to the new article of
manufacture which consists of a tubular member made by helically
winding a strong, shaped metallic steel strip having an S or Z
shaped section in accordance with the foregoing process, said
tubular member being principally characterized by an excellent
resistance to internal and external pressure, by substantial
flexibility which permits it to be wound on cores of relatively
small diameter, and a perfectly cylindrical shape which it retains
while being bent.
The present invention also relates to the new article of
manufacture which consists of a flexible tube for use in drilling
oil wells essentially characterized by the fact that it comprises a
strong flexible tubular steel member as above defined.
The present invention is also directed to a device for carrying out
the foregoing process, which device is essentially characterized by
the fact that it comprises in combination: means for bringing the
shaped metallic strip at a suitable speed into a plane
substantially tangent to the tubular member which is being formed;
means for imparting a permanent arcuate deformation to said strip,
the side of the strip located in the direction in which the tubular
member is being formed having a length greater than the other side
of the strip; means consisting, for example, of forming fingers for
imparting to said strip a helical deformation about a diameter
which corresponds substantially to the diameter of the tubular
member, thus assuring the engagement of the coil being formed with
the coil which has just been formed; means for guiding the tubular
member formed in this manner, and means for synchronizing the
rotation of the tubular member which has been formed and the
arrival of the strip from which the tubular member is to be
made.
The means for imparting an arcuate deformation to the strong steel
strip may advantageously consist of a set of rollers bending the
strip beyond its elastic limit.
In one particular embodiment of the invention, the means for
imparting a helical shape to the strip may advantageously consist
of a forming head having a plate mounted through a universal joint
on a framework so as to be adjustable in its operating position by
swinging it about both a horizontal axis and a vertical axis.
This plate comprises a central orifice through which the tubular
member is formed. About the periphery of this orifice are means
such as T shaped notches to which the supports for the various
forming fingers may be attached.
In one embodiment of the invention the supports for the forming
fingers make it possible to regulate the angular orientation of the
fingers with respect to a direction radial to the tubular member
and the distance of the fingers from the axis of the tubular member
being formed.
Other properties and characteristics of the invention will appear
in the course of the following description of a preferred
embodiment of the invention, which is being given purely by way of
example, and with reference to the accompanying drawings, in
which:
FIG. 1 is a schematic elevational view of a machine for carrying
out the process according to the invention;
FIG. 2 is a top plan view of the machine of FIG. 1;
FIG. 3 is a schematic perspective view showing how the shaped
memallic strip is formed into a helix in accordance with the
invention;
FIG. 4 is a partial sectional view of an enlarged scale taken
through the axis of a tubular member manufactured in accordance
with the invention;
FIGS. 5, 7 and 9 are elevational view taken transversely of the
axis of a tubular member, and FIGS. 6, 8 and 10 are corresponding
side views taken during various steps of the formation of the
tubular member according to the invention;
FIG. 11 is an elevational view taken transversely with respect to
the axis of the tubular member, showing the forming fingers and
their supports; and
FIG. 12 is a schematic sectional view taken along the line 12--12
of FIG. 11.
FIGS. 1 and 2 show the overall layout of a machine for carrying out
the process according to the invention. In particular, these
figures show a reel 1 on which a tube of plastic material 2 is
wound. This tube is intended to constitute the inner lining of the
tubular member according to the invention. The reel 1 is mounted on
a support 3 which rotates about a horizontal axis.
Another reel 4 carries the tubular member 5 according to the
invention and is mounted on a support 6 which also rotates about a
horizontal axis.
The reel 4 is rotated with respect to the support 6 by a motor 7
through a conventional transmission 8, which is schematically
shown.
The shaped high strength steel strip 9 is unwound from a reel 10
rotatably mounted on a stationary support. This shaped strip 9,
driven by two pairs of rollers 11, reaches the forming head 12
after having passed over the rollers 13 which impart an arcuate
shape to it. The device for curving the shaped metal strip is shown
on the other figures in a more detailed manner. Beyond the forming
head the shaped strip 9 is converted into the tubular member 5
which then passes through a traction cage 14 which rotates about a
horizontal axis and comprises driving rollers 15 which engage the
tubular member 5 and drive it along an axial path.
An electric motor 16 drives a shaft 17 through a set of pulleys and
belts. This shaft extends the full length of the machine and
controls, through reduction gearing 18 and belts or chains, the
horizontal rotation of the support 6.
It also controls, through reduction gearing 19, the rotation of the
traction cage 14, and through reduction gearing 20, the rotation of
the rollers 15 which axially advance the tubular member.
Similarly, the shaft 17 controls through reduction gearing 21 the
rotation of the pairs of rollers 11 which axially advance the strip
9. Finally, the shaft 17 drives the cage 3 through reduction
gearing 22.
A brake 23, which is only schematically shown, restricts the
unwinding of the plastic tube 2 which is coiled on the reel 4,
after having been encased in the tubular member manufactured in
accordance with the invention.
The speeds of rotation of the different members which have been
described are so determined as to coordinate the speed of rotation
of the tubular member 5 and the speed at which the strip 9 advances
to form the member 5 in question.
The different components to which reference has been made have not
been individually described in a more detailed manner because these
components, when considered individually, are well known in the
cable manufacturing industry.
The device for carrying out the process according to the invention
is shown in a more detailed manner on the perspective view of FIG.
3.
This figure shows the two pairs of rollers 11 which drive the strip
9 at a suitable speed. The section of this strip is shown on a
larger scale at the left of FIG. 3.
The rollers 11 have shapes such that the strip 9 is lead flat to
the table 24, which is provided with two forming rollers 13.
The axes of these rollers are mounted so that they turn freely and
their positions may be adjusted by screw means 25, which are
schematically shown. These rollers 13 cooperate with a third roller
26 designed to turn the strip 9 toward the forming head.
The forming head, which is indicated as a whole by reference
numeral 12, consists of a plate 27 mounted by means of a universal
joint on a support 28.
This universal joint mounting permits the plate 27 to pivot on two
arms 29 about a horizontal axis 30. The plate 27 is attached to the
arms 29 by screws 31 seated in arms 29 and passing through
semicircular holes 32 in a member fixed to the plate 27.
This arrangement permits the position of the plate 27 to be easily
adjusted by pivoting it about the horizontal axis 30.
A second adjustment of the plate 27 with respect to a vertical axis
results from the fact that the arms 29 are connected to each other
by a cross member 33 which is provided with oblong holes 34 through
which the bolts 35 which attach the cross member 33 to the base 28
pass.
It will be understood that, under these conditions, by releasing
the bolts 35, it is possible to pivot the cross member 33 slightly
and thus turn the plate 27 about a vertical axis.
Finally, the cross-member 33 is mounted on bolts 35 between
adjustable nuts which make it possible to adjust the height of the
plate 27.
The plate 27 (which, as has already been explained, may be adjusted
in all directions) comprises a central hole 36. The tubular member
5 which is formed by the strip 9 passes through this hole.
The plate 27 comprises a groove 37 encircling the orifice 36. This
groove has a T shaped section and receives the heads of the bolts
38 by means of which the supports 39 for the forming fingers are
attached. In the present case these supports 39 are four in number,
but may be more or less in number.
Each support is attached to the plate 27 by bolts 38 which pass
through elongated orifices of circular shape in the supports 39 so
that the latter may be angularly adjusted in a radial plane with
respect to the plate.
In like manner the supports 39 which carry the forming fingers 40
may be adjusted in an axial direction by threaded rods 40a.
It will be seen that under these conditions, as many forming
fingers as desired may be mounted and each of these fingers may be
set in any position necessary to obtain satisfactory regulation of
the machine.
FIG. 3 also shows that the circular groove 37 communicates with a
lateral groove 37a through which the bolts 38 may be
introduced.
FIGS. 11 and 12 are two views showing the forming fingers 40 and
the adjacent parts of the machine on a larger scale. Thus FIG. 11
shows the part of supports 39 for the forming fingers 40.
FIG. 12 shows schematically in section the tubular member 5 which
is being made from a strip which, in the present case has a very
schematic S shape, and the profile of the forming finger 40
corresponding to this specific shape of the strip 9.
FIG. 4 shows in section on a larger scale the upper part of a
tubular member according to the invention made from a strip having
a different shape.
In this case the strip 9 has a generally S shape having two hooked
edges 9a and 9b which are connected to the main part of the strip 9
by grooved portions 9'a and 9'b.
As seen on FIG. 4, the formation of the tubular body is such that a
hooked edge 9a of a coil engages in the grooved part 9'b of the
next coil while leaving a little play between the two hooked edges
9a and 9b which engage each other.
As will be hereinafter explained, these coils are preferably so
formed that the coils have a tendency to press resiliently against
each other. It follows that the edge of each coil 9b bears
resiliently against the vertical flank of the recess 9'a or 9'b of
the adjccent coil while leaving the unoccupied space 41 clearly
shown on FIG. 4.
It is because of the existence of this space 41 that the tubular
member according to the invention has an exceptional flexibility.
In effect, as may be seen on FIG. 4, it is possible by imposing a
sufficient force to overcome the elastic force which holds the two
coils together, to bring two adjacent coils into contact through
only the two projecting hooked members 9a and 9b.
It will thus be seen that due to the space 41, which leaves a
certain play between the coils, it is possible to impart to the
tubular member according to the invention a relatively great
flexibility. However, according to the preferred embodiment of the
invention, the coils are resiliently urged against each other so
that the tubular member according to the invention has a tendency
to spontaneously return to its straight form.
The method of making the helical coil of the strip 9 in accordance
with the preferred embodiment of the invention will now be
described.
FIGS. 5 and 6 show the first step in the formation of the helical
coil according to the invention.
FIG. 5 is an elevational view transverse to the axis of a tubular
member being formed, and shows the profile of the first coil. In
order to make this, the shaped strip 9 arrives along a straight
path 42 after passing through the forming rollers which have
imparted a curved shape thereto as may be clearly seen in FIG. 6.
The forming fingers impose on the part 42 which advances in the
direction of the arrow F a resilient curvature at 43, which results
in a permanent deformation at 44 corresponding substantially to the
diameter of the tubular member which is being manufactured.
As may be clearly seen on FIG. 6, the arcuate deformation which is
imparted to the strip 9 is such that the strip is spontaneously
helically wound toward the bottom of the FIG. 6 (arrow F1) in the
form of a helix having coils which are not connected to each
other.
In order to produce the tubular member according to the invention,
the part 44 of the strip 9 is caused to cross the first loop formed
not below, but above (FIG. 6). This begins the coil which is shown
in FIG. 8.
It will, however, be appreciated that because of the natural shape
of the coil which is formed when the helix is forcibly coiled
upwardly, while this helix would be formed spontaneously in a
downward direction, the part 44 of the coil which forms (FIG. 8) is
elastically urged against the part 42 which forms the previous
turn.
FIGS. 9 and 10 show the evolution of the formation of the tubular
member upwardly and it will be seen that when the member 44 has
been passed above the part 42 (FIG. 8), the helical shape which
results must necessarily continue to be formed in this direction
(FIG. 8, FIG. 10).
This results in the formation of a tubular member 5 in which the
different turns engage each other as has been clearly explained
with reference to FIG. 4, while the turns are urged elastically
against each other by reason of the phenomen which has just been
described.
It will also be appreciated that the degree of force by which the
different turns of the spiral are urged against each other may be
regulated by regulating the directions and magnitudes of the
deformations imposed upon the strip.
The tubular members which are made in accordance with the invention
have particularly valuable properties for numerous applications,
and especially in the case of flexible tubing for use in drilling
oil wells.
It is particularly easy to form the flexible tubular member about
the tube of plastic material which is designed to make it
fluid-tight.
In like manner, the tubular member has the advantage of offering a
great resistance to internal and external pressures even though
being very flexible, which makes it possible to wind the tubular
members according to the invention on cores of sufficiently small
diameter to make them easy to transport and handle.
It will of course be appreciated that the embodiment which has just
been described has been given purely by way of example and may be
modified as to detail without thereby departing from the basic
principles of the invention.
In particular, it is clear that the sections of the strong steel
strip which have been shown on the drawings have been given only by
way of example, and the strip may be given other shapes depending
upon the nature and characteristic of the tubular member which is
to be manufactured.
* * * * *