Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PIPI~-LC)CKI~G FORMATION METHOD AND APPA~ATVS
FIELD OF THF INVF~Nl`ION
This invention relates to a method of applying arcuate radially-
extending lockinv projections on the ends of pipes formed from a formable
meta~, such as carbon steel or stainless steel, and to apparatus specifically
emp~oved in the performance of the method.
~7hile not limited thereto, the present flpplication finds
particlllar application in the forrnation of such locking projections on tile r
ends of otherwise plflin-ended pipe which is to be assembled into a pipeline
assembly by the use of so-called "quick-connect" couplings.
Such couplings usually comprise arcuate coupling member
halves having radially extendin~ bolt pads at their ends. The respective
coupling member halves are positioned around the adjacent ends of a pair
of pipes in bridging relationship therewith, and are clamped to each other
by bolts or the like. The clarnping member halves include an internal
channel for the reception of an annular gasket member which has been
pre-positioned over the pipe ends in bridging relationship therewith, or, for
the reception of a gasket member segment which is located and secured
within the channel of each of the coupling member halves, and which is
brought into bridging and sealing engagement with the pipe ends upon
flssem~ly of the coupling onto the pipe ends. The clamping member halves
include a pair of internal grooves or channels for interlocking enagement
with the projections on the pipe ends, such interlocking engagement
preventing separation of the pipes under the action of pressure or vibration,
and effectively limiting the amount of axial and angular displacement of
the pipes relative to each other and the coupling.
The invention finds particular application in pipeline assemblies
forme<l from thin-walled stainless steel pipe, such as is commonly employed
in the food processing, chemical, wood pulp and paper manufacturing
indllstl ies, ~hich the fluids to be conveyed are under pressure, and axial
separation of the pipe ends must be inhibited under all normally expected
processing conditions. Attempts at employing plain-ended pipes and an
appropriately configured coupling rnember have not been entirely successful,
in that .slippage of the pipe or the pipe ends relatively to the coupling
member can occur under conditions of mechanical vibration, or pulsation
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or overpressure of thc conveyed fluids, or, a combination of such conditions.
~hile provision on the coupling clamping members of incissor type teeth
provides some improvement in performance, it has been found that on
relatively thin walled pipes such devices have limited performance in terms
of restraining the pipes against separation due to pressure thrust, mechanical
vibration and other forces that can occur in a piping system. In addition,
the risk arises of damAging the pipe walls through buckling under the teeth
or puncturing of the pipe walls. Consequently, and particlllarly where thin
walled pipes are utilized, it is found desirable to provide a positive interlockbetween the respective pipe ends and the coupling member in order that
separation of the pipe ends cannot occur up to the maximum pressures
nor mallv associated with such thin \~alled pipes.
A` known form of positive interlock, as is disclosed, for
example, in United ~tates Patent Serial No. ~,0~1,132, Johnson, issued May
19, 1936, involves the formation of the pipe ends with radially outwardly
extending arcuate projections which are received within grooves at the
respective axial ends of the coupling member, the arcuate projections
cooperating ~with the walls of the grooves to provide a positive interlock
between the pipe ends and the coupling and to inhibit axial displacement
or angulflr displacement of the pipe ends relatively to the coupling and to
each other.
While such an arrangement is admirable in those conditions
where the pipeline assembly can be pre-planned and the respective pipes
cut to determined length and formed at their ends with the required
arcuately extending projections at the point of manufacture of the pipes,
problems arise in those conditions where the pipeline assernbly must be
adapted at the point of assembly to hitherto unknown or ~lncomtemplated
conditions and which preclude the use of completely formed and finished
plpes.
BA(~I~GROUND OF THE INVENTION
It is the object of this invention to pro~ide a rnethod and an
apparatus for forming the reqllired arcuate radially-extended locking
projections on the pipe ends at the actual point of assembly of the pipes
into a pipelinc asserr)bly, thus permitting the ready fabrication of a pipeline
assemhlies from standard stocl< lengths of pipe, or from non 'standard lengths
of pipe cut from standard stock lengths of pipe
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By forming tl)e arcuate locking projections on to the pipes at
the point of assembly rather than at the point of manufacture, the in-
transit handling of the pipes is greatly facilitated, and, the problem of in-
transit damage of the arcuate locking projections is eliminated in its
entirety.
While thc formation of the arcuate projections on the pipes
at the point of assembly of the pipes would appear, superficially, to be a b
relatively simple matter, the finished forrrl and relative position of the
arcuate projections is in fact a matter requiring substantial accuracy, for r
example, if the projections are too close to the pipe ends then the coupling
~il] not be in the correct relative position so that the ~asket may overhang
the pipe ends and leakage will occur, alternately, if the projections are
skewed to the longitudinal uxis of the pipe, difficulty will be encountered Ea
in assembling the couplin~ with possible malfunction and leakage occuring.
Also, for proper performance of the coupling it is desirable that the
projections lie in the sarne plane, perpendicular to the longitudinal axis of
the pipes. Further, many of the pipes include a longitudinal seam. In such
irlstances, the arcuate projections must be set off from the seam line.
~dditionally, distortion of the pipe from its truly circular condition must
be minimi%ed~ and axial or radial displacement or distortion of the pipe
ends should be avoided, or incomplete seating of the gasket can occur and
the compressive stressing of the gasket throughout its circumference will
not be constant, such conditions militating against satisfactory sealing of
the pipe ends at the coupling
OBJECT OF T~E INVE~TION
It is an object of this invention to provide a method and an
apparatus specifically for use in that n~ethod, whereby either standard
lengths of pipe or cut lengths of pipe, including seamed pipe, can be
accurately formed at the assembly site with the required arcuate projections
in the absence of any significant radial or axial distortion of thc pipe ends
such ns ~lould irnpair the sealing and locating capabilities of the coupling.
According to one feature of the invention, there is provided
a mc~hod of forrning pipe ends with radially extending arcuate projections,
which includes the steps of dividing the external cicumference of the pipe
into spaced forrning zones positioned respectively on each side of the
]ongi~lldinal weld or seam in instances where the pipe is of welded
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construction, mar!~ing said zones on the exterior surface of the pipe, locating
the pipe against axial or ]ateral displacement, employing a first said zone
marking as an index of the locntion of a second zone spaced from said
first zone, appiving clamping pressure to the material of said pipe within
second 7.0ne to hold said materia] against axial pull--back of the pipe materialfrom the ends, effecting the formation of one said radial extending arcuate
projection from within said pipe at said zone while maintaining said
clamping pressure, releasing both the clam~ing and forming pressure and
sequentiall~ repeating the operation at each other said zones.
According to another feature of the invention, there is provided
an flppnratus for carrying out ~he method of the invention, the apparatus
including an axially straight bed frame on which a pipe support member is
slideably mounted for movement to a determined position, the pipe support
member being lockable to the bed frame when in a selected position
longitudinally thereof. At one end of the bed rame there is rigidly secured
thereto a forming head including a stop member for engagement by and
accurate positioning of a pipe end, and a female die member fixedly
supported in the forming head in a determined position spaced forwardly
from said stop member and intermediate the stop member and the pipe
support member. A male punch member is movably supported within the
forming head for vertical movement towards and away from the female
die member, such movement being generated by the action of a suitable
r~otive force. The ~!orking portion of the male puncil member extends
from behind the stop member and forwardly thereof into alignment with
the female die member, such that the male punch member is contained
within the ends of a pipe supported on the female die.
Preferably, the male punch member is provided with a
retractable clamping shoe which forms the dual function of clamping a pipe
end against the surface of the female die upon advance of the male punch
member, and, stripping of the pipe -from the male punch mernber upon
retraction of this member.
The pipe support member is mounted on its associated guide
mcmbers for pivoting movelnent in a horizontal plnne, and, is adjustable
in height in order to bring a pipe which is generall~ supported by the pipe
SlJpport member and the female die into an orientation in which its
longitudinnl axis i~ ~xlrallel to the bed of the apparatus and at 90 to the
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plane of the stop mernber and forming head. Additionall~, the pipe support ,~
member preferably includes universally pivoted members which, in addition
to facilitating rotation of the pipe to permit the successive radially extending ,~
arcuate members to be formed, also facilitates axial movement of the pipe
in order that the pipe end may be readily introduced into the forming head
and removed therefrom subsequent to the formation of the respective
arcuate projections.
T)ESCRIPTION OF THE ACCOMPAI~IYI~IG DRAWINGS
The invention will now be described with reference to the
accompanying drawings, in which:
Figure 1 is a side elevation of the
apparatus according to the present
invention;
Figure 2 is a plan view thereof;
Figure 3 is a cross-section thereof
taken on the line 3-3 of Figure 1;
Figure 4 is a vertical cross-section
taken through a forming head of the
appnratus, line 4-4 of Figure 5; -~
Figure 5 is a front elevation of the
forming head of Figure 4 taken on
the line 5-5 of Figure 4;
Figure 6 is a plan view of the
forming head;
Figure 7 is an enlarged partial view
of Figure 5 showing the die and
punch assembly in greater detail,
and is also a view taken through
the line 7-7 of Figure 3;
Figure 8 is a vertical section taken ;-
on the line 8-8 of Figure 7;
Figure 9 is an under side plan view
of the male punch assembly and
combined clamping member
- strioper llead of Figures 7 and 8;
Figure 10 is a fragmentary cross-
.
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section elevation of the pipe support member
of the apparatus;
Figures 11 and 12 are respectively a front
elevation and plan view of a gauge to be
used in combination with the apparatus of
the invention and
Figures 13 and 14 are respectively an end
elevation and side elevation of the gauge of
Figures 11 and 12 when applied to the end of
a pipe.
Referring now to Figure 1 to 3 of the drawings,
there is shown an apparatus according to the present
invention, the apparatus including an axially straight bed
12, which is supported by legs 14 having load distributing
ground-engaging pads 16. As more clearly shown in Figure
3, the bed 12 can conveniently be comprised of two spaced
beams 12a of C-shaped transverse cross-section, the arms
of the respective beams facing each other, the respective
beams 12a ~eing interconnected at convenient points to
further improve their dimensional stability.
Supported on the bed 12 and slideable longitudi-
nally thereof is a plate 24 which is clampable to the bed
12, by clamping bolts 20. The clamping bolts 20 each have
an enlarged head which engages the under side of the upper
2~ arms of the beams, and a shank which extends upwardly
between th~ upper arms of the beams, and throu~h a hole in
the plate 24, the bolts being located in position by
appropriate nuts~ When the bolts are released, they act
AS guide members permitting the plate 24 to be slid
3Q axially of the bed 12 to a required determined posî~ion
longitudinally of the bed 12, the shanks of the bolts
sliding within the space between the spaced upper arms of
~ the beams 12a/ and acting to guide the plate 24 in its
; movement longitudinally of the bed 12. The plate 24
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normally will be positioned a distance from the operative
face of a forming head, indicated generally at 22, which
is one-half the length of the particular len~th of pipe to
be worked upon in the forming head.
The plate 24 supports a vertical post 26, the
post 26 in turn supporting a pipe support member 28. As
is later described with reference to Figure 10, the pipe
support member 28 is mounted via the post 26 for pivoting
movement in a horizontal plane, and to raise or lower the
pipe in order to accommodate pipes of diferent diameters,
and, to accurately position a pipe of a particular diameter
in correct elevation relative to the female die 620
In Figures 1 to 3, a pipe 3~ is shown supported
by the pipe support member 28 for the purposes of clarity
of illustration. It will be
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understood that the pipe 30 is the workpiece to be worked upon, and, that
the pipe 30 itself forms no part of the apparatus.
The pipe forming head 22 preferably is a unitary sub-assembly,
which, for purposes of convenience in transporting the apparatus from one
site to ~nother, preferably is detachably attached to the bed 12 by any
convenient means which will ensurc a rigid and immovab]e connection
between the bed 12 ~nd the forrning head 22. Similarly~ for the purposes
of ease of transportation, the pipe suppor~ member 28 and its associated
components are removable from the bed 12. Y
Referring now to Figures 4~ 5 and 6, which illustrate the
forming head in detail, the forming head 22 includes a main frame comprised
of a horizontal base member 32 which supports a pair of spaced vertical
members 34. The vertical members may be formed unitarily with the
horizonal member 32 as a unitary casting, or, they may be plates welded
or otherwise secured thereto. At the upper ends, the spaced vertical
members are interconnected by a horizontal platform S2, which, similarly
may be formed integrally with the horizontal member 32 and~spaced vertical
members 34 as a unitary casting, or, be welded or otherwise secured thereto
in any convenient manner.
Secured to the respcctive spaced vertical members 34, by
means not shown, are a pair of vertically arranged and parallel aligned
guides 40, which, in conjunction with face plate 42c, guide and support a
carriage 42 for vertical reciprocating movement between the spaced vertical
mem~ers 34. The face plate 42c is removably attached to the carriage 42.
The pipe forming head 22 has an abutment plate 44 secured
to the face thereof facing the pipe support assembly 28, which is secured
to the vertical members 34 by any convenient means such as by screws 46.
At its upper end, the carriage includes a forwardly extending
boss 42a which underlies the platform 52, and, which is connected to the
plunger 47 of a hydraulic piston and cylinder arrangement 48. The plunger
47 of the piston and cylinder arrangement extends downwardly through an
aperture in the platform 52 to the boss 42a. The plunger 47 being
interconnccted by a bolt 50.
The piston and cylinder arrallgement 48 is fastened to the
platform 52, one means being by threaded connection.
The piston and cylinder arrangement, which preferably is
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hydraulically operated, can be of the one-way acting type,
the piston of the arrangement being returned by spring 54,
which may be contained within the piston and cylinder
arrangement/ or, be external thereto for the spring rate to
be adjustable. The cylinder is provided with a suitable
inlet connection 56 permitting the cylinder -to be connected
to a supply of hydraulic fluid under pressure, the supply
and the valving arrangement thereof forming no part of the
present invention.
At its lower end, the carriage 42 is provided with
a forwardly extending boss 42b which extends through an
aperture 44a in the plate 44, the clearance being required
in that the boss 42b travels within the plate aperture 44a.
Attached to the under face of the lower boss 42b
is a male punch assembly 58, the male punch assembly being
secured to the lower boss 42b in any convenient manner,
such as by bolts which are not shown. The male punch
assembly has a punch 58a which cooperates with a female die
member 62 which is rigidly attachPd to the horizontal mem-
ber 32b by means of bolts which are not shown. Preferably,
and as shown, the female die member is located on a key 32a
in the horizontal base member 32b in order to locate it
relative to the punch assembly 58.
The female die member 62 is arcuate and substant-
ially semicircular in elevation, the radius of the inner
periphery of the female die member being the same as that
of the exterior periphery of the pipe 30. Internally of
its inner periphery, the female die member 62 is grooved,
as indicated at 62b, the axial width of the groove
representing the width of the radially extending arcuate
projections 30a to be formed in the pipe 30. The groove
62b is continuous throughout the entire inner periphery of
the female die, thus permitting the groove to accommodate
more than one formed arcuate projection and permitting
eotation of the pipe about its longitudinal axis subsequent
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to the formation of one or more projections.
As is more clearly illustrated in Figure 4, upon
a forming stroke of carriage 42 and the male punch assembly
58, the punch 58a thereof will enter into the groove 62b of
the female die member 62, and in so doing will displace
radially ou~wardly a portion of the wall of the tube 30 to
form a radially-extending arcuate pro~ection 30a in the
periphery of the wall of the pipe 30.
~igure 4 illustrates the carriage when in a
10 retracted position and prior to the supply of hydraulic
fluid under pressure to the piston and cylinder arrangement
48. It is in this position of the male punch assembly 58
that the pipe is inserted into the forming head, the pipe
being positioned such that at least one point of its end
15 face contacts the abutment plate 44. This ensure~ that the
formed radially extending arcuate projections 30a are
positioned at an exact distance from the free end of the
pipe 30.
Pre~erably, and in order to obtain an indication
20 that the forming operation has been completed, a pressure
gauge ~4 is associated with th~ piston and cylinder
arrangement 48, the gauge 64, during operation of the
forming head exhibiting a rise in pressure at a constant
rate as the carriage 42 is forced downwardly against the
25 bias of the springs 54, followed by a sudden increase in
pressure as the male punch engages the inner wall of the
pipe 30, the gauge then indicating a further gradual rise
in pressure as the forming progresses. Once the forming
operation has been completed and further downward movement
30 of the male punch assembly 58 is inhibited, the pressure
gauge 64 will then show a sudden and sharp rise in pressure
to the maximum line pressure, thus giving to the operator
a clear indication that the forming operation has been
successfully completed.
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As is illustrated in Figures 7 through 9, the
male punch assembly 58 can be provided with a clamping
member 66 which is movable relatively to the male punch
assembly 58, and which is biased to an extended position
by springs 68. The extended position of the clamping
member 66 is limited by post bolts 70 having heads which
abut the punch assembly 58 and having posts which are
slideably received within bores in the male punch assembly
58, the ends of the posts being threaded into threaded
bores in the clamping member 66.
In operation the clamping member 66 serves two
purposes, the first being, on advance of the male punch
assembly 5~ to engage the inner periphery of the pipe 30
and clamp it firmly against the inner periphery of the
female die member 62~ This clamping force resists axial
creep or deformation by the pulling of material from the
free edge of the pipe and results in an improved
appearance of the pipe end and an enhanced dimensional
form of the arcuate projections 30a. Secondly, the
clamping member 66 by virtue of the bias imposed thereon
by the springs 68 acts in the function of a stripper
mechanism as the male punch 58a is retracted, thus ensuring
that the pipe be left in seated engagement with the female
die member 62 so avoiding any lif ting action of the pipe
caused by jamming
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between the punch 58a and the arcuate projections 30a.
Conveniently, both the female die members 62 and the male
punch as~embly 58 are detachably attached to their respective supporting
members by bolts, thus permitting ready removal of both of the assemblies
for exchange with another pair of assemblies of different radius for use
with a pipe of a corresponding diameter different to the one shown in the
drawings.
Referring now to Figure 10, tbere is more clearly illustrated
to the manner in which the pipe support member 28 is constructed and
supported by the vertical post 26. The post 26 is tubular in forrn and
internally threaded. The lower end of member 72 is male threaded at 72a,
and is received within post 26, and allows for axial vertical adjustment via
a plurality of pins 78, only one of which is shown. Such pins are secured
to member 72. (~)n rnember 72 exists a cylindrical nut 74. A plurality of
pins 76, only one is shown, are attached to the cylindrical nut 74 to allow
for rotation of the cylindrical nut 7~ relative to the threaded portion 72a
of member 72. The cylindrical nut 74 acts as a jam nut to secure post
72 re]ative to post 26 after a vertical position has been established.
Received within a bore 72b in the upper end of the cylindrical
member 72 is a rotatable shaft 80, the rotatahle shaft being secured against
removal from the bore by a threaded pion 82 having an end which is
received within a groove 80a in the rotatable shaft 80. Cylindrical oil
retaining anti friction bearings 84 are located within the bore 72b and
rotatably support the shaft 80, and, a thrust bearing 86 is positioned in
the bottom of the bore and provides the required support for the shaft 80
and the structures supported by the shaft.
As is more clearly illustrated in Figure 10, the pipe support
member 28 is supported by the shaft 80 by means of a U-shaped yoke 88
which is welded or otherwise secured to the upper end of the shaft 80.
The arms of the yoke extend upwardly, and, are welded or otherwise secured
to a right angled channel member 28a whose arms are arranged at an angle
of 45~ to the hori~ontal. Carried by both arms of the channel member
28a are baUs 90 received within anti-friction housin~s 92, the anti-friction
housing being rigidly attached to the respective arms of the channel member
28a with the balls contained therein freely rotatable universally in any
direction. The balls 90 provide for both rotation of the pipe about its
axis, and, movement of the pipe longitudinally of its axis witn equal facility.
By provid;ng plural sets of balls and anti-friction housings, the pipe support
rnember 28 is adapted to receive and support pipes of ~idely varying outside
diameters, as is indicated by the chain-dotted lines in Figure 10.
In addition to providing for rotary and axial movement of the
supported pipes, the pipe support member 2g also provides for swinging of
the pipe into and out of the ~orming head 22~ thus. greatly facilitating the
handling of the pipe. Additionally, by virtue of the adjustable supporting
posts, the pipe support member can be raised or lowered as necesary in
order to bring a horizontRI tangent at the bottom of the end pipe into co~
planar relationship with a horizontal tangent at the botton of the female
die, thus ensuring tllat the longitudinal axis of the pipe, without reg~rd to
its diameter, is brought into position in which it is perpendicular to the
face of the abutment plate 4~. In this way, inaccuracies in the positioning
1.5 of the formed arcuate radial projections 30a relative to the end face of
the pipe are minimized to the greatest possible çxtent, or, are eliminated
in their entirety.
Turning now to Figures 11 through 14, which illustrate a gauge
90 which has particular utility in the performance of the method of the
present application, the gauge illustrated is formed from a flex~ble flat
strip of metal or other suitable material having upturned ends 94a. In use,
the gauge 94 is wrapped around a pipe of appropriate external diamter,
and, the flanges 94a thereof are brought into parallel relationship with each
other with the flanges 94a positioned on opposite ends of the weld seam
30a of the pipe, assuming, of course, that the pipe is a welded pipe.
The gauge may either be hand held, or, any convenient means
may be used for holding the gauge in position during the rnarking of the
pipe end to provide indications of the location of a plurality of forming
zones equally spaced about the external circumference of the pipe. The
3 respective locations are determined by notches 94b forrned in one
longitudinal edge of the gauge, the respective notches including a scribing
or marking edge which extends transversely of the gauge, and which thus
extends axially of the pipe when the gauge is applied to the pipe end.
Having correctly located the gauge close to the pipe end, a scribe or rnarker
is then used îo rnark on the exterior periphery of the pipe the location of
the respective forrning zones, as determined by the transversely extending
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edges o~ the notches 94b.
The marking of the pipe for the forminy zones to be
spaced on opposite sides of the weld seam 30b ens~res that the
weld seam shall not accidently be positioned within a forming
zone, but instead shall be positioned between an ad~acent pair
of ~orming zones. It is here commented that the ductility of
the metal forming the pipe varies at the weld seam, and, that
any attemp~ to form the pipe with a radially extending arcuate
projection which extended through the weld seam could result in
fracturinc3 of the weld seam or perforation thereof by cracking
or partial splitting of the weld seam, conditions which must be
avoided in that the arcuate projections are positioned beyond
the ends of the sealing gasket. The positioning of the zones
circumferentially of drawn pipe is, of course, immaterial in
that there is no weld seam to be contended with.
Having ensured that the end of the pipe is sufficiently
square for the intended end purpose, and having marked the posi-
tions of the respective forming zones, the pipe is then placed
on the pipe support member 28, this operation being facilitated
in that the pipe support member 28 can be swung in a horizontal
plane, thus eliminating the necessity of initially placing the
pipe in the required position relative to the forming head 22.
Having placed the pipe in the pipe support member, the
pi~e and the pipe support member 28 can then be rotated until the
end of the pipe is in alignment with the opening in the female die.
By then axially sliding the pipe on the pipe support
member ~8, the end of the pipe to be formed can be brought into
abutment with either the female die 62 or the abutment plate 44.
It can then be determined whether the pipe support member 28 and
thus the supported pipe must be raised or lowered in order that
the lower outside edge of the pipe is coincidental with the tan-
gent through the bottom of the radial opening in the die. The
adjustment of the vertical position of the pipe support member
2~ is effected by applying rotational force to the pins 78~ which
in turn causes rotation of member 72, the threads 72a in co-
operation with the internal threads of post 26 cause the pipe
support arrangement 28 to be raised or lowered dependin~ upon the
direction of rotation and the direction of the screwed thread.
The arrangement is secured in a given position against further
rotation by rotating the nut 74 via the pins 76 until it abuts
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the top of the post 26. The pipe, so supported, can now be rotated without
further affecting the height of its longitudinal axis.
Having accurately positioned tl-e location of the longitudinal
axis of the tube in a vertical plane, the pipe is then slid into the female
die member 62 and into race contact with the abutment plate ~4, assuinK,
of course, that it was not initially in engagement with the abutment plate
44. At this point, the longitudinal axis of the pipe will be parallel to the
bed of the machine and thence at 90 to the abutment plate 44.
The pipe is then rotated about its longitudinal axis to bring
any one of the previously applied m arks on its periphery hereof into
registration with an alignment mark or index mark on the forming head
22. Hflving done this, the punch assembly 58 is then moved downwardly,
thus moving the punch 58a and the clamping member 66 into engagement
with the inner surface of the pipe wall. The pipe is thus clamped in
position, and, the formation of a radially extending arcuate projection 30a
proceeds by the displacement of the metal beneath the punch 58a into the
grooved forming channel ~2b of the female die member 62.
Upon retraction of the male punch assembly 58, the clamping
member 66 acts to strip the pipe from the punch 58a, and, hold the pipe
in seR~ed engagernent with the female die member 62 until such time as
the post bolts 70 abut on the punch assembly 58 and prevent further
downward movement of the clamping member 66. At this point, the
clamping member ~6 moves upwardly and out of engagement with the pipe.
The pipe is then rotated about its longitudinal axis to bring
the ne~t marking on the circumferenc`e of the pipe into alignment with the
alignment mark on the forming head 22, during which time the formed
projection 30a rides within the groove or channel 62b, this having the
additional aclvantage of preventing unintentional movement of the pipe
relative to the female die member 62 and ensuring that subsequent arcuate
projections lie in the same plane perpendicular to the pipe longitudinal axis.
The male punch member is then again operated to form the next radially
extending arcuate projection 30a, and, this sequence is repeated until all
of the arcuate projections 30a are formed.
As will be appreciated, the method of the present application
provides that neither the inciex mark on the forming head 22 or marking
for the zone on the pipe to be formed needs to be positioned within the
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actual ~one of formation, at wh;ch point it would be extremely difficult
to observe. Instead, the index on the forming head 22 is located in a
position in which it is readily viewable by a workman and generally without
regard to which side of the apparatus is employed as the work station by
the worl~man.
Various modifications may be made in the specific structure
of the apparatus without departing from the scope of the invention as
defined by the appended claims. For e~ample, in substitution for the
hydraulic piston and cylinder arrangement 48, any other convenient source
of pressing force could be employed, including mechanical and electro-
mechanical devices, such as a manual source comprised by a cam follower
cnrried by the carriage 42 and which cooperates with a rotary cam carried
by the platform 36, the cam having associated therewith a lever which is ~D
mamlally operable by the workman to rotate the cam. Alternatively, the
rotary cam could be one which is driven through an appropriate gear r
reduction chain from an electric or other motor.
With respect to the vertical lift mechanism for the pipe support
member 28, clearly, other structures such as cam-operated lifts or
hydraulically operated lifts could be employed where convenient, the major
requirements in the apparatus being that the pipe 30 shall be positionable
with its longitudinal axis truly perpendicular to the face of the abutment r~
plate 44 and correctly positioned in height relative to the female die
member 62, and, that the male punch assembly 58 move in a plane which
is truly parallel to the plane of the abutment plate 44 and perpendicular
to the longitudinal axis of the pipe.
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