Note: Descriptions are shown in the official language in which they were submitted.
961~
This relates to devices for connecting pipe sections,
without the use of welding, particularly for use in the oil and
gas industry.
Present pipeline construction techniques entail use of
welding to join abutting ends of pipe sections. The use of
welding for this purpose is relatively time consuming and requires
the use of skilled labour which is expensive and sometimes diffi-
cult to obtain.
The present invention is adapted to provide a coupling
device which is of such size and configuration as to permit a
permanent connection of the ends of pipe sections, without the
necessity of welding and at the same time to provide an uninter-
~upted continuous surface on the inæide the pipeline at the
attachment area.
In accordance with the present invention there is pro-
vided in a device for joining pipe sections, first and second
generally tubular sleeve means adapted to be attached to an end of
a first and second pipe section, respectively, each said fir~t and
second sleeve means having a cylindrical internal surface with
pointed projections thereon, said projections being adapted to
engage the outer surface of said pipe sections and to resist with-
drawal of said pipe sections from said sleeve means, each said
sleeve means including a frusto-conical surEace inclined at a
shallow angle to the axis of the sleeve means, said frusto-conical
surface being adapted to engage a mating frusto-conical surface to
form a seal therebetween, a generally cylindrical connector
adapted to fit over at least part of said first and second sleeve
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means, said connector having an internal cylindrical surface with
screw means thereon, said first sleeve means ha~ing an outer
cylindrical surface with screw means thereon adapted to co-operate
with said screw means on said connector, whereby as said connector
is ro~ated said screw means on said sleeve and connector cause the
ends of the pipe to be drawn toward one another and said frusto~
conical mating surfaces to be forced into tight engagement with
one another.
In accordance with the present invention there is also
provided a device for joining pipe sections comprising Eirst and
second generally tubular sleeve means adapted to be attached to an
end of a Eirst and second pipe section, respectively, each said
-~irst an~ second sleeve means having a cylindrical internal sur-
face with pointed projections thereon, said projections being
adapted to grippingly engage the outer surface of said pipe sec-
tion and to resist withdrawal of said pipe section from said
sleeve means, each said sleeve means including a frusto-conical
surface inclined at an angle of between S and 10 to the axis of
the sleeve means, a generally cylindrical connector adapted to fit
over at least part of said first and second sleeve means, said
connector havin~ at least one internal cylindrical surface with
screw means thereon, said connector having frusto-conical surfaces
thereon which are adapted to mate with said frusto-conical sur-
faces on said sleeve means to form seals, said first sleeve means
having an outer cylindrical surface with screw means ther~on
adapted to co-operate with said screw means on said connector,
whereby as said connector is rotated said screw means on said
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sleeve and connector are caused to interact to draw the ends of
the pipe toward one another and to force said frusto-conical
mating surfaces into tight sealing engagement with one another.
In accordance with the present invention there is also
provided a device for joining pipe sections comprising first and
second generally tubular sleeve means adap~ed to be attached to an
end of a first and second pipe section, respectively~ each said
first and second sleeve means having a cylindrical internal sur-
face with pointed projections thereon, said projections being
adapted to engage ~he outer surface of said pipe sections and to
resist withdrawal of said pipe sections from said sleeve means,
each said sleeve means including a frusto-conical surface inclined
at a shallow angle to the a~is of the sleeve means, said frusto
conical surface on said ~irst sleeve means being adapted to engage
and mate with said frusto-conical surface on said second sleeve
means to form a seal therebetween, a generally cylindrical con-
nector adapted to fit over at least part of said first and second
sleeve means, said connector having at least one internal cylin-
drical surface with screw means thereon, said first sleeve means
having an outer cylindrical surface with screw means thereon
adapted to co-operate with said screw means on said connector,
whereby as said connector is rotated said screw means on said
sleeve and connector cause the ends of the pipe to be drawn toward
one another and said frusto-conical mating surfaces to be forced
into tight engagement with one another.
In accordance with the present invention there is also
provided a device for joining pipe sections comprising first and
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second generally tubular sleeve means adapted to be attached to an
end of a first and second pipe section, respectively, each said
first and second sleeve means having a cylindrical internal sur-
face with pointed projections thereon, said projections being
adapted to engage the outer surface of said pipe section and to
resist withdrawal of said pipe section from said sleeve means,
each said sleeve means including a frusto-conical surface inclined
at a shallow angle to the axis of the sleeve means, said frusto-
conical surface being adapted to engage a mating frusto-conical
surface to form a seal therebetween, a generally cylindrical con-
nector adapted to fit over at least part of said first and second
sleeve means, said connector having at least one internal cylin-
drical surface with attachment means thereon, at least one of said
sleeve means having an outer cylindrical surface with attachment
means thereon adapted to co-operate with said attachment means on
said connector, said attachment means on said sleeve means and
said connector each comprising a helical groove, said grooves
forming a helical passage when placed in juxtaposition, said con-
nector including a slot communicating with said helical groove
therein for feeding wire into said passage; whereby as said
helical groove in said sleeve is positioned within the end of said
connector and said wire is fed through said slot into said
passage, the frusto-conical surface on said sleeve will be drawn
inwardly of said connector and into firm contact with said mating
frusto-conical surface.
In accordance with the present invention there is also
provided a method of joining pipe ends comprising press fitting a
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sleeve having serrations on the inner surfaces thereof over a pipe
end, locating a connector having a helical groove therein over a
helical groove in the outer surface of the sleeve, feeding wire
through a slot in the connector into a chamber formed by the
grooves on the connector and sleeve, rotat:ing the connector to
cause the wire to be drawn into said chamber to produce a screw
and thread ef~ect causing the sleeve to be drawn inwardly of the
eonnector and causing a seal to be formed at a frusto conical
surface on said sleeve to thereby form a tight connection.
In drawings which illustrate embodiments of the inven-
tion:
Figure 1 is an illustration partially in cross-section,
of a Eirst embodiment of a pipe section connecting device, in an
assembled state.
Figure la is an illustration of certain of the com-
ponents of the embodiment of Figure 1 in an unassembled state.
Figure 2 is an illustration partially in cross-section,
of a further embodiment of a pipe section connecting device, in an
assembled state.
E`igure 3 is an illustration partially in cross-section,
of a further embodiment of a pipe section connecting device, in an
assembled state.
Figure 3a is an illustration of an alternative embodi-
ment of the device illustrated in Figure 3O
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Figure 4 is an illustration partially in cross-section,
of a further embodiment of a pipe section connecting device, in
an assembled state.
Figure 5 is an illustration partially in cross-section,
of a further embodiment of a pipe section connecting device, in
an assembled state.
Figure 6 is an illustration partially in cross~section,
of a connecting sleeve in accordance with the invention.
Figure 7 is an illustration partially in cross-section,
of a further embodiment of a connecting sleeve in accordance
with the invention.
Figure 8 is an illustration partially in cross-section,
o~ a Eurther embodiment of a connecting sleeve in accordance
with the invention.
Referring now to Figure 1, there is shown a first
embodiment of the invention in an assembled form, connecting the
ends of pipe sections 13 and 14. The apparatus comprises sleeves
11 and 12 and connector 10. Sleeve 11 is generally tubular
in shape and has an inner cylindrical surface 40 of a first
diameter and an inner cylindrical surface 41 of somewhat
larger diameter than that of the surface 40. Surface 40
includes serrations 20 therein consisting of circumferential ridges
for gripping the outer surface of an adjacent pipe section.
The ridges may be formed by machining threads having a generally
regular triangular cross-section. Preferably, however, the
cross-sectional shape of the ridges is that of an irregular
triangle wherein the side of the triangle nearest the centre of
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the sleeve is shorter than the side of the triangle nearer the
end of the sleeve. This shape results in an inclination to
the ridges which serves to provide less resistance to inward
movement of the pipe relative to the sleeve, and at the same
time to resist a tendency to withdrawl of the pipe by biting
into the surface thereof in response to a force tending to
pull the pipe outwardly. Surface 40 also includes spaced
recesses 21 which are adapted to serve as resevoirs for
holding expoy resin used in mounting the sleeves on the pipe
sections.
The outer surface 44 of the sleeve 11 includes a
continuous helical slot 29 extending around the circumference
khereo~. The end o the sleeve 11 adjacent the slot 29
includes a surface 33 which is inclined to the longitudinal
axis of the sleeve at a shallow angle thus forming a
frusto conical surface 33.
The second sleeve 12 is identical to the sleeve 11
as described above.
The connector 10 includes an outer cylindrical
surface 48 and inner cylindrical surfaces 46 and 47 situated at the
ends thereof. The diameter of the surfaces 46 and 47 is slightly
greater than the diameter of the surfaces 45 and 44 of sleeves
12 and 11 thereby permitting the connector to be rotated
relative to the sleeves.
The connector also includes a central inner cylindrical
surface 37, the diamaeter of which substantially, corresponds to
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the inner diameter of the pipe sections 13 and 14. Between
the central cylindrical surface 37 and the cylindrical surface
47, there is a frusto conical surface 36 which is congruent to
and adapted to mate with, surface 35 on sleeve 12. Similarly
frusto conical surface 34 on the other sicLe of the central
cylindrical surface 37 is congruent to ancl adapted to mate
with, surface 33 on sleeve 11.
On the surface 47 of the connector 10 there is
situated a continuous helical slot 32 which corresponds to
the slot 30 in the sleeve 13. Similarly surface 46 carries
a continuous helical slot 22 which corresponds to the
slot 29 in the sleeve 11.
Slots 100 and 105 are situated at the ends of the
connector 10 and are preferably slightly tilted to the radius
to facilitate feeding wires 23 and 31 into -the helical groove.
To assemble the pipe connector device the sleeves 11
and 12 are first mounted on the ends of the pipes 14 and 13.
This step may be carried out either at the pipe manufacturing
facility or in the field. Prior to mounting the sleeves,
an epoxy resin is spread in the recesses 21 and 17 and in
the serrated portions 20 and 17 of the inner surface of ~he
sleeves. The sleeves 11 and 12 are then pressed into place
over the ends of the pipes 14 and 13 until the ends of the pipe
sections contact abutment surfaces 49 and 50. The epoxy resin
serves as a lubricant to permit easier passage of the sleeves
and when the sleeves are in place it serves to fix the
961~
sleeves to the pipe sections. The epoxy resin also serves to
seal the connection against the ingress of moisture from the
outside which would tend to cause corrosion in the connecting
device and to seal the connection against the escape of fluids
carried by the pipeline~
The end of wire 23 is bent at a right angle and the bent
portion is positioned in slot 101 in sleeve 11 illustrated in
Figure l(a). Connector 10 is then slid over the end of the
frusto conical surface 33 with the slot 100 in the connector
aligned with slot 101 in the sleeve until the sleeve can travel
no further. At that point, the free end of the wire 23 emerges
through the slo~ 100 and the end of the wire 23 will be
anchored against displacement by the right angle bend in it
situated in slot 101, upon a slight rotation of the connector.
The end of wire 31 is similarly bent at a right angle
and placed in corresponding slo~ in the slee~e 12. The sleeve 12
is then pushed as far as it can go into the connector 10 with the
corresponding slots in alignment and with the free end of the
wire 31 emerging from the slot 105.
The connector 10 is then rotated so that wires 23 and
31 are drawn throucJh the slots 100 and 105 on the ends of the
connector 10 and are laid in the helical grooves 22 and 29 on
one end and the helical grooves 32 and 30 on the other end.
The wires 23 and 31 mate with the slots in the connector and
sleeves in a screw and thread fashion and because the slots are -
oppositely threaded, rotation of the connector serves to
draw both sleeves into the connector. As rotation of the
connector 10 continues, frusto conical surfaces 35 and 36
and 33 and 34 will eventually contact and lodge within one
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another to form a firm connection. Axial forces produced by
the connector are transformed into substantial radial forces at
the frusto conical surfaces, which are inclined at a shallow angle
to the axis. This creates a tendency to expand the element with
the female frusto conical surface and provides a tight connection
between the elements through high contacting forces present over
the relatively large area of the contacting frusto conical surfaces.
With the rotation of the connector 23 and 31 are
deformed to tightly fit the slots within which they are
situated thereby to prevent backing off of the connector.
Referring now to the embodiment of the invention
shown in Figure 2 the major portions of which comprise sleeves
55 and 56 and connector 57. Connector 57 is substantially tubular
in shape and has helical grooves 22 and 32 winding in opposite
directions, situated on the inner cylindrical surface 58 thereof.
Sleeve 56 includes circumferential serrations or ridges
17 and recesses 18 on its inner cylindrical surface 43.
The outer cylindrical surface 45 includes helical grooves 30 which
match grooves 32 on the connector 57. The end of the sleeve
56 adjacent the grooves 32 is inclined at a shallow angle
to provide a frusto conical outer surface 51 which is adapted
to mate with a frusto conical surface 52 on the sleeve 55,
Inner liner cylindrical surface 53 of sleeve 56 is of substantially
the same diameter as that of pipe 13. The diamater of the
inner cylindrical surface 43 of the sleeve 56 is slightly
less than the diameter of the outer surface of pipe section 13 to
enable the sleeve 56 to be press fitted on the end of the
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pipe section 13. Sleeve 55 includes circumferential ridges 20 and
recesses 21 on the inner surface 41. The upper surface 44
includes helical grooves 29 matching grooves 22 on the
connector 57. The end of the sleeve 55 adjacent the helical groove
22 is inclined at a shallow angle relative to the longitudinal
axis of the sleeve to provide a frusto conical inner surfac~
52 adapted to mate with a congruent surface 51 on the sleeve
56. The diameter of the inner cylindrical surface 41 of the
sleeve 55 is slightly less than the outer diameter of the pipe 14
to enable the sleeve 55 to be press fitted on the end of the pipe.
The assembly procedure is similar to that used
with the first embodiment. The sleeves 55 and 56 having a
layer of epoxy resin on the inner surfaces to provide lubrication
and to assist ~onding, are press fitted on to the ends of
pipe sections 14 and 13. The connector 57 is then slid over
sleeve 56 and the sleeves 56 and 57 are aligned and correctly
spaced~ A bent end of wire 23 is placed in a slot (not shown)
on the outer surface of sleeve 55 and connector 57 is slid over
the end of sleeve 55 with slot 102 on the end thereof in
alignment with the slot on the sleeve 55 and wire 23 emerging
therefrom. The conne~tor 57 is then rotated until slot 103
coincides with the slot in the surface of sleeve 56. The bent
end of wire 31 is placed in the slot in the sleeve 56 with the
free end emerging from slot 103. The connector 57 is then
rotated causing the wires 23 and 31 to be drawn into and laid
down in the helical grooves in the connector and sleeves thereby
acting as screws and threads. Because one acts as a left
hand screw and thread and the other acts as a right hand
screw and thread, rotation of the connector 57 will serve
to draw both of the sleeves into the connector. Eventually
the frusto conical surfaces 51 and 52 on the sleeves 56 and
55 will contact and firmly mate to form a strong bond. At
the same time the wires 23 and 31 will tightly fit the helical
grooves to produce a permanent connection and seal.
It will be appreciated that when the device is assembled
with the pipe sections, the inner surfaces of the pipe sections
14 and 13 together with the surface 53 of the sleeve 56 will
form a smooth substantially continuous surface which is
uninterrupted by discontinuites in cross-section.
In the embodirnent shown in Figure 3 the sleeve 60 includes
an integral ring 15 on its outer surface. The connactor 58
includes an inwardly projecting flange 61 having surface 16
adapted to rotatably bear on surface 28 of the ring 15. It will
readily be appreciated that the connector coacts with the sleeve
60 by means of the contacting flange 61 and ring 15.
Connector 58 is slid to the right exposing frusto
conical surface 18. Sleeves 59 and 60 are axially aligned and
brought together with female frusto conical surface 19 on
sleeve 59 contacting male frusto conical surface 18 on sleeve 60.
Connector 58 is slid to the left with slot 108 in alignment
with the slot on the surface of the connector 59. The bent end
of wire 23 is placed in the slot on the onnector 59 with
the free end emerging through slo-t 108. The connector 58 is
then rotated causing wire 23 to be laid in slots 29 and 22 and
creating a force tending to press the sleeves 59 and 60 together.
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An advantage of this embodiment which employs a single
thread and a pair of coacting rings, is that it permits the
connector to be slid back and the sleeves to be fully engaged
before the connector is screwed into place to provide the
engaging force on the sleeves.
As with the other embodiments a substantially
continuous inner surface is provided by the inner walls of
the pipe sections 14 and 13 the surface 64 of sleeve 59 and
the surface 27 of sleeve 60 and a strong connection is formed by
the mating frusto-conical surfaces.
Figure 4 discloses an embodiment which is
substantially similar to Figure 3. Instead of using a wire
situated in a helical grove as a thread, a thread 68 has
been machined on the outer surface of the sleeve 65. The thread
68 is adapted to engage the connector 66 and to provide,
upon rotation of the connector, the engaging force which
causes frusto conical surfaces 69 and 70 to mate and form a
strong union.
The embodiment of Figure 4 is particularly suited for
use where it is desired to be able to disconnect the pipe
sections, since the use of the machined thread permits the
connector to be disassembled and reassembled.
Figure 3a shows a further embodiment wherein the pipe
ends abut one another at 114 thus permitting contact only
between the pipeline and the contents thereof and avoiding any
contact between the material of the sleeves and the contents of
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the pipeline. Such an arrangement is particularly suitable for
avoiding corrosion, particularly where the pipeline is adapted
to carry sour gases.
As will be seen from Figure 3a, the sleeves are fitted
on the ends of ~he pipe sections so that the end of pipe section
14 upon assembly substantially coincides with the inner edge of
frusto conical surface 112 on sleeve 110 and the end of pipe
section 13 upon assembly substantially coincides with the outer
edge of frusto conical surface 111 on sleeve 109.
The procedure for assembling the device will be
essentially the same as described in relation to the embodiment
oE Figure 3. Upon assembly chamfered edges of the ends of the
pip~s 1~ and 13 will form a V-shaped ring 115 containing epoxy
resin to Eorm a seal.
It will be appreciated that the embodiments of Figures
1, 2, 4 and 5 may similarly be constructed so that the ends of
the pipe abut in order to avoid contact between the contents of
the pipeline and the material carried by the pipe.
The embodiment shown in Figure 5 includes a locking
ring 7~ mounted in a circumferential slot 77 in the sleeve 76.
The locking ring is composed of high tensile steel and has a
gap therein which permits it to be elastically deformed to a
required extent. After the sleeve 76 with the ring 72 mounted
in slot 7~ therein, is fitted on the end of pipe section 14,
connector 71 is then mounted by inserting it over tapered end of
the sleeve 76 and pressing it in the direction of the ring
72. Chamfered surface 73 on the forward end of connector 71
will contact chamfered surface 75 on the ring 72 and continued
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pressure on the connector will cause the ring 72 to be
compressed thus permitting surface 78 on the connector 71
to ride over the ring 72. When the ring 72 reaches the area
79 of enlarged diameter it will spring back into its original
shape thereby locking the connector 71 in the position shown
in Figure 5. The ring is dimensioned to permit movement of the
connector 71 relative to the sleeve 76.
To connect the pipe sections 13 and 14, to which sleeves
76 and 77 are attached~ the pipes are axially aligned, and
frusto conical surfaces 80 and 81 are pressed into engage~ent.
The connector 71 is then brought into contact so that the threaded
surfaces 83 and 82 engage and the connector 71 is rotated to
produce the engaging force on the melting frusto conical surfaces.
In order to obtain optimum locking engagement of
the mating contacting frusto conical surfaces in the previously
described embodiments, such surfaces should be inclined at a
relatively shallow angle, preferably in the order of between
5 and 10 degrees to the central axis thereof.
The wire used as threads in the foregoing embodiments
ma~ comprise a high strength low carbon steel having a yield
strength in the range of 60,000 to 80,000 psi.
Figure 6 illustrates a connector consisting of a
single sleeve 85. Sleeve 85 is adapted to be attached to
ends of adjacent pipe sections by force fitting the sleeve
85 into the inside of the ends of the pipe sections. The
sleeve 85 includes circumferential serrations or sharp
ridges 81 of gradually decreasing diamater toward the ends
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of the sleeve. The maximum diameters of the ridges are
slightly greater than the inside diameter of the pipe sections
to be joined. The sleeve 85 also includes a central portion 84
having maximum thickness and maximum outer diameter. The
ends of the central position 84 include recesses 83 and 82
for receiving and holding the ends of the pipe sections therein.
To join pipe sections the ends of the sleeve are
forced into place inside the pipe sections using a larger of epoxy
resin as a lubricant and sealing means, until the ends of the
pipe are positioned in and are lodged in recesses 82 and 83.
The emhodiment illustrated in Figure 6 is adapted for
use in a low pressure pipeline.
The connector illustrated in Figure 7 comprises a
single sleeve 86 for force fitting over the ends of adjacent
pipe sections, to join the pipe sections.
The connector 86 includes inner cylindrical surfaces
91 at each end having a diameter slightly greater than the
outer diameter of the pipe sections to be joined. In the
central region of the sleeve 86 there is a recess 87 the
diameter of which is slightly greater than the outside
dia~eter of the pipes. This recess is used as a reservoir
for epoxy resin. On each side of recess 87 there is a
cylindrical sur~ace 89 having a diameter slightly less than
the outside diameter of the pipes. Between surfaces 89 and
surface 91 there are a series of circumferential sharp
ridges or seratives 90 the maximum internal diameter of
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which is slightly less than the outer diameter of the pipe.
As with the other embodiment the sharp edges of these ridges
are directed somewhat to ward the centre of the sleeve to
facility entry of the pipe into the sleeve and to provide a
biting action into the pipe to resist withdrawal of the
pipe.
To join pipe sections, epoxy resin is spread in
the areas of recess 87 and serratiors 90 and the pipe ends are
forced into the respective ends of the sleeve 86 until the
abut at the centre of area 87.
Figure 8 illustrates an embodiment simila~ to that
o~ Figure 7 but i~cluding recesses 92 in the area of
s~rra~ions or ridges 90, which serve as epoxy resin reservoirs.
This device is assembled in a similar manner to that described
in relation to the embodiment illustrated in Figure 7.
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