DE1959160A1 - Method and device for corrugating pipes - Google Patents

Description

Patent attorneys

Dr. Incr. Wilhelm Eeiahel

Dipl-Ing. WcIi:; aij η ..: ώθ1

6 francs a. U. 1

Parksircaie 13

6084 PHELPS DODGE COPPER PRODUCTS CORPORA.TIOU, New York, V.St.A.

Method and device for corrugating pipes

The invention "relates to a method and an apparatus for corrugating pipes, in particular a method and a device for the continuous processing of pipes, to alternately form corrugated and non-corrugated sections.

It is known that corrugated tubes exhibit better properties in heat transfer applications due to the combination of increased turbulence in the medium and the increased heat exchange area created by the corrugations. However, it is necessary that the heat exchange tubes do not have corrugated or smooth sections at certain points so that the. Manufacture and assembly of heat exchanger systems is possible. For example, the pipes must not be corrugated at connection points where the pipe is connected to another. Pipe or pipe connection is connected or engages in this to ensure the production of a proper seal without the use of tangled sealants. Known corrugation methods and devices for this purpose automatically and continuously provide the tube with corrugations

009827/1: 2 24. && original

however, they are unable to provide non-corrugated sections at predetermined locations along the pipe for predetermined lengths without disrupting the continuity of operation of the device. Furthermore, known "devices with regard to limited their capacity to form deep corrugations with a uniform contour. Where numerous parallel Corrugations are to be formed, known devices often cause the pipe surfaces to buckle between depressions, resulting in an alternating series of flats and ridges instead of the desired continuous series of Wave back leads.

The invention is therefore based on the object of a method and to provide an apparatus for automatically deforming tubes continuously so that they are alternately corrugated and have non-corrugated portions of predetermined lengths, whether the pipe is of intermediate, fixed, or arbitrary length Length. At the same time, the method and the device are intended to enable the continuous production of a large number of enable continuous corrugations that have considerable depth, improved contour and uniformity.

According to the invention, this object is achieved by a device of the type indicated at the outset, which is characterized by a head to which a tool for making corrugations is attached, a device that axially moves the pipe relative to the mold, a device that allows relative rotational movement between the mold and the Tube generated around the tube axis, and by a device that presses the forming tool either firmly into contact with the tube, while the tube continues to move axially relative to the forming tool.

009827/1224.

Briefly summarized, the invention enables in one embodiment continuous, longitudinal non-rotating movement of a pipe on a number of forming tools past. The forming tools can rotate around the pipe axis and are equipped with automatic control devices, which cause the forming tools to reciprocate radially relative to the pipe. A movement of the forming tools radially inward towards the pipe axis has the consequence that the tools around their corresponding points of contact on the pipe Depress an amount equal to the depth of the desired corrugation. A combined axial movement of the tube and ™ Rotation of the tools creates helical corrugations. When receiving a signal, e.g. from limit switches along the path of movement of the pipe, the tools are withdrawn from the pipe or, in other words, radially outwards moves while ^ they continue to rotate about the pipe axis and while the pipe continues to travel lengthways past the tools. The withdrawal of the tools and the continuation Movement of the pipe results in a non-corrugated pipe section. After the pipe a predetermined distance has been moved, the tools are moved radially inward again to create additional helical corrugations to train. (

In order to improve the production of uniform deep corrugations with the correct contour, the pipe is pressurized on the inside. A pressure relief valve is provided to keep a constant Maintain pressure as the internal volume of the pipe is reduced in the manufacture of the corrugations.

The invention will now be described in detail with reference to the accompanying drawings, all of which are derived from the description and the Figures emerging details or features can contribute to the solution of the problem within the meaning of the invention and .Included in the application with the intention to be patented

009827 / 1224-

Show it:

Pig. 1 is a side view of the tube corrugating device according to the invention, partly in section;

Pig. 1A is a schematic representation of the drive system for the Pig device. 1;

Pig. Figure 2 is an enlarged end view of the tool support of the Pig device. 1 along line 2-2 in Pig. 1;

Pig. 3 is a sectional view of the tool support of the Pig. 2, along section line 3-3 in Pig. 2 and

Pig. 4 is a schematic representation of a hydraulic system and a seal through which the tube is internally pressurized as the corrugations are formed can be.

Reference is now made to the drawings, in particular Pig. 1 # This shows a preferred embodiment of a tube corrugator 3 according to the invention. The corrugating device mainly contains a support frame 10 on which a support housing 12 is firmly attached. A sleeve 13 is supported by the housing 12 and divided at one end 14 in the longitudinal direction, to form an assembly of clamping fingers 15, one of which every one of its outer surface is bevelled outwards «

Near the si aiifierea Ea de 16 eier sleeve 13 is an outer c "i" i? _ö Γ "" * I ■ "1 °" ^ "2 j Lief * - ¹ ^ e-"; T <lse18

diameter of the sleeve 13 at its corresponding end 14, whereby the clamping fingers 15 are operated in a manner that will be described will.

A tube 20 to be corrugated is moved through the sleeve 13 by any conventional device, such as a gripper 22 with a number of spaced apart pipe clamping devices which automatically grasp the pipe in order to move it further and then release the pipe. Promoters of this type are known, and an education i conduct is described in US Patent 3,023,300, issued on February 29 1962nd The sleeve can be adjusted by means of the clamping fingers 15 so that it can accommodate pipes with slightly different diameters. If a locking nut 23, which is screwed onto the threaded portion 17 of the sleeve, is rotated in a counterclockwise direction, this has the consequence that the sleeve 13 according to .Fig. 1 is moved to the right, the clamping fingers 15 being released from the sleeve 18, the fingers being able to expand and receiving the tube 20. After the tube protrudes slightly beyond the end 14 of the sleeve 13, the locking nut is carefully turned clockwise, whereby the sleeve 13 is moved to the left as shown in FIG. Such movement pushes the flared end of the fingers 15 against and into abutment with the stationary sleeve 18, the fingers being drawn together around the tube 20 to create the necessary pipe socket without the axial movement of the tube through the sleeve prevent.

The tube 20 is moved for producing corrugations on a number of dies 24 which are supported for executing a radial movement to and from the tube axis 26 generating holder away by working 28th The tool holders 28 are again

009827/1224

to attached to a face plate 30, which is on the stationary Hollow shaft 18 is rotatably mounted about the pipe axis 26. Each forming tool 24 creates a corrugation and the number of tools used is determined by the number of desired ones Corrugations determined within the spatial limits of the pipe diameter.

The end plate 30 is formed from a circular plate 32 and an annular edge 34, which on the plate 32 approximately through Welds 36 is suitably secured. The edge 34 is provided on its periphery with a plurality of teeth 38 to a Form drive interface for a conventional drive belt 40 that rotates the face plate 30. The radially inner end 42 of the plate 32 is welded to an elongated sleeve 44 which surrounds the stationary sleeve 18. An expanded part 46 of the Sleeve 44 receives the outer Lsufring 48 of a ball bearing 50, the inner race 52 of which is fastened to the stationary sleeve 18 and is held there by a locking nut 53. The other end of the sleeve 44 is rotatable by conventional bearings such as roller bearings 54 with an adjacent grease seal 56 supported around the stationary sleeve 18.

A number of equally spaced tool holders 28 are releasably attached to the face plate 30, one of which is shown in detail in FIGS. The faceplate for a 25.4 mm (1 inch) diameter tube is machined to accept 2, 3 »4, 5, 6, 8, or 10 equally spaced tool holders 28. The device 8 can be adjusted to produce all these numbers of corrugations. Each tool holder 28 contains a housing 58 which is fastened to the face plate 30 by conventional eyebolts, and the housing 58 has a partially continuous sliding guide 60. Within the guide 60 a Crleitstein 02 is mounted " • lev with a bored cylindrical recess 64 a · ^ lower ".: -: Aa 66 Tensphen is «In the recess 64 is eU-.r ilonaiz ^f ~ 3 ^: iw V :: ri: 5 <iU £ haltsrs 65 housed »the a / Io ο Iv-- o & ^ j

009827/1224

BATH ORIGINAL

having fork-shaped radially inner end 70. The molding tool 24 for forming the corrugations, such as a Pormro He or a forming wheel 72, is on the radially inner * end 70 of the tool holder 69 rotatably mounted. The circumferential shape of the wheel 72 has the desired contour of the corrugations that are formed by this wheel are. The shaft 68 is provided at its upper end with a conical part 74 which terminates in a shoulder 76. The generally cylindrical shape of the shank 68 enables the tool carrier 69 to rotate around a radial one Can rotate axis 78 which passes through the tool holder 28, thereby adjusting the alignment of the wheel 72 with respect to " is made possible on the pipe axis 26, and also the pitch angle can be adjusted to the desired pitch or to maintain the twist of the corrugation to be produced. To the tool carrier To lock 69 in the correct position for the desired pitch angle, a clamping piece 80 extends in the form of a screw transversely through the tool holder housing 58 and is in contact with the conical part 74 of the tool carrier shaft 68. The screw rests against the shaft to lock it in the adjustment position.

The radially outer end 82 of the sliding block 62 has the shape of a yoke or a fork (see FIG. 2), and in the yoke is one Roll 84 stored. The roller 84 is carried by a shaft 86 which extends through the sliding block 62 and through openings 88, 90 extends on opposite sides of the housing 58. Both outer ends of the shaft 86 are provided with a groove 92 which one end of a coil spring 94 receives. The other end of the coil spring 94 is at the protruding end one Fixed pin 96 which extends from the radially outer end of the housing 58 to the outside. Since the sliding block 62 is unimpeded Can move within the housing 58, the coil springs pull the G ^ tfciAfct ^ n, radially outward from the tube-r

axis 2 6 way. In the .Gehäuse 58 is next to the role 84 and on this aligned a second roller 98 rotatably mounted. Aligned openings 100, 102 extend through the face plate 32 and rear wall 103 of the tool holder housing 58 in FIG a layer aligned with rollers 84,98. Another opening 104 extends through the front wall 106 of the tool holder housing 58, and this opening is also aligned with openings 100,102. The purpose of these openings 100, 102, 104 is to enable the passage of a wedge 108 through the housing 58 and between the rollers 84 and 98, in the manner and for the purpose described below.

A wedge control plate 110 is supported by a cylindrical sleeve which is slidably mounted on the faceplate sleeve 44. Two diagonally and spaced apart pins 112, one end attached to plate 32, extend through openings 113 in control plate 110 to align wedge 108 with respect to rollers 84, 98 and the common rotational movement of the face plate 30 and control plate 110, while at the same time allowing relative axial movement of control plate 110 with respect to face plate 30. The wedge 108 is pivotably attached at 114 to a retraction pin 116 which in turn is carried by the control plate 110. Like from Pig. 3, the wedge 108 has parallel walls 120, 121 at its forward end which then gradually diverge a short distance from one another until the walls 120, 121 are again parallel, as shown at 122. The difference between the distances between the parallel parts of the wedge 108 gives the distance of movement of the sliding block 62 and wheel 72, since the wedge 108 is normally with the narrower end between the adjacent rollers 84, 98, as from Pig. 2 shows. The wedge 108 therefore determines the depth of the corrugation. The depth of the corrugation can also be adjusted by means of a depth adjustment screw 123 , which is positioned through the end plate edge 34 in alignment with an adjustment block 124.

009827/12 2 Λ '

ORIGINAL INSPECTED

stretches, which forms the upper part of the tool holder 28 ". The Adjustment block 124 is provided with a G-threaded hole, the one Receives clamping screw 125 which extends through an elongated hole 126 in a side wall of the tool holder. if it is desired to adjust the depth of the corrugation, the clamping screw 125 is loosened and the adjusting screw 123 in a corresponding one Moved direction, with the adjustment block positioned will. The adjustment block 124 is yoke-shaped or fork-shaped and supports the upper roller 98.

When it is desired to move the wheel 72 radially inward to form corrugations in the tube 20, the wider portion of the Wedge 108 inserted between rollers 84 and 98. As the outer roller 98 through the clamping screw 125 and the adjustment block 124 is fixed in the setting position, the force exerted by the wedge 108 is transmitted via the inner roller 84 to the sliding block 62, whereby it is moved radially inward against the biasing force of the helical springs 94. To the axial movement To generate the wedge 108, a sleeve 126 is mounted on the control plate sleeve 111. The sleeve 126 is supported by pressure roller bearings 128, 130 supported, which allow rotation of the sleeve 111 and control plate 110, while the sleeve 126 is stationary. In order to move the sleeve 126 in the axial direction, an angle lever 132, which is pivotably mounted on two arms 134, engages via pins extending from the support frame 10 into the sleeve 126. The other end of the bell crank 132 is with the Pistons of a reciprocating motor such as a pneumatic motor 136 are connected. Switching on the motor causes a Pivoting the angle lever 132 according to Pig. 1 clockwise, which moves the sleeve 126 axially against the face plate 30. This movement pushes the wedge 108 between the rollers 84, 98, causing the wheel 72 to be in a position for forming the Corrugations is brought. After the pipe 20 has passed the wheel 72 a predetermined distance and the desired pipe length deliberately plumb, switches an iilgnal, e.g. from an Enäeohaltor, the Motor 136, which distributes the Hufjfo l ^ wn-ter i front plate 30 ^ 3,

resulting in a partial retraction of the wedge 108 from the Space between the rollers 84, 98 leads to the position in which the narrowest part of the wedge 108 is between the rollers. It will be noted that there is a corresponding wedge 108 for each mold 24 and the insertion and withdrawal of the wedges takes place simultaneously during the rotation of the end plate 30 and the further movement of the tube 20. When the wedge 108 is withdrawn, the combined retraction force of the coil springs 94 and centrifugal force drive immediately the sliding block 62 and the wheel 72 outwardly away from the tube 20.

As can be seen from FIG. 1A, the entire tube corrugating device 8 is driven by a drive motor 138 with variable speed, which drives the end plate 30, the motor 136 and the gripper conveyor 22 via suitable conventional transmission means. A suitable coupling device that operates the motor 136 is actuated by signals obtained from switches or a programmed signal source. If a pipe is to be corrugated with an intermediate length, the entire operation can be programmed so that predetermined lengths of the pipe are corrugated and alternate with predetermined non-corrugated sections. For the pail that pipes with a fixed length are to be corrugated, limit switches, 'arranged at certain points along the path of movement of the pipe 20, generate the signals for the motor coupling »

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together with the tube corrugating device 8, which is above j there are restrictions on the depth he ■ Welly ag en formed v / e-rcleri! soimoiij without ·? "1ηβ Hii ^ n

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has the consequence, instead of the desired continuous series of wave ridges. The exact depth to which corrugations can be formed depends on the pipe diameter, the pipe wall thickness, the pipe material and the density of the corrugations. In order to increase the depth to which corrugations can be precisely formed, in order to further improve the contour and uniformity of the corrugations, the tube 20 can be pressurized inside by a medium. Pig. 4, a hydraulic system HO, by means of which a tube 20 of predetermined length ...- schematically shows pressurized and pressure are kept constant g can, when the tube 20 passes through the corrugating apparatus and is corrugated.

In order to seal one end 141 of the tube 20, it is hollow Plug 142 (see enlarged section) with an axially continuous bore 143 partially fitted into one end of the tube 20. The portion of the plug 142 within the tube has one Diameter roughly equal to the inside diameter of the pipe. The plug 142 then tapers, creating a conical reducing shoulder 144 is created. A ring with a beveled front end 148 is disposed around the plug. The ring is locked on the plug 142 by a locking nut 150, which also presses the ring against the tube 20. It can be seen (that when the lock nut 150 is tightened against the ring 146 and the ring is pressed against the tube 20, the tube is bent against the plug shoulder 144 and thereby an absolutely tight one Sealing is established.

In order to pressurize the tube 20, a conventional hydraulic pump 152 is in communication with the tube via the bore 143 in the plug 142. The system 140 further includes a pressure regulating valve 154, a pressure gauge 156 and a Entlüftungsfcehälter 158th

009827/1224

The opposite end 160 of the tube 20 is closed by a similar sealing device. If a hollow When plug 142 is used, a cap 162 is sealed onto the end of the plug; however, cap 162 may omitted if a solid plug (not shown) with the same shape as the plug 142 is used.

Before the corrugation process begins, the hydraulic pump 152 generates the required pressure in the pipe. For a copper-nickel tube of 25.4mm (1 inch), a pressure of about 126 kg / cm (1800 psi) has been found to be successful. If that Tube 20 is corrugated, the internal volume of the tube is continuously reduced, which leads to the fact that the medium pressure increases. The pressure regulating valve 154, however, keeps the pressure relative constant by allowing some of the medium to escape into the vent tank 158. After the tube is corrugated the plugs 142 are removed and the deformed pipe ends severed from the pipe.

The corrugating device described above works as follows: The drive motor 138 is switched on, so that the end plate 30 and the forming tools 24 rotate about the pipe axis 26 and the gripper conveyor 22 is put into operation. A tube 20 to be corrugated is conveyed through the sleeve 13 at a desired speed. If desired or necessary due to the depth or shape of the corrugations, the tube 20 can be pressurized. Usually it is preferred not to corrugate the beginning of the pipe, since the end of the pipe will likely have to be connected to a pipe connector. Accordingly, only after a predetermined length of the pipe has passed the forming tools 24, the motor 136 is actuated, with the result that the wedge 108 is completely inserted between the rollers 84, 98. The introduction of the wedge 108 causes the sliding

SAD ORIGINAL

Stone 62 and dies 24 move radially inward a distance equal to the desired depth of the corrugation. It will be remembered that the face plate 30 is rotating about the pipe axis 26 at this point in time. The combined axial movement of the pipe 20 and the rotary movement of the forming tools 24 about the pipe axis 26 produce helical corrugations, the pitch angle being predetermined by the position setting of the forming wheel 72. The pitch of the helix is determined by the speed of the end plate 30 and the speed of the pipe 20. The corrugated process is continued for a predetermined period of time or for a predetermined length of tubing, depending upon whether a programmed f or operated by a switch control device is used. When it is desired to stop corrugating the tube, a signal is applied to motor 136 which causes angle lever 132 to pivot counterclockwise and further causes sleeve 126 to move away from face plate 30, thereby removing the wedge 108 is partially withdrawn. The combination of the force of the retracting coil springs 94 and the centrifugal force created by the rotation of the faceplate causes the slide block 62 and dies 24 to instantly move radially outward as the faceplate continues to rotate and the tube 20 continues past the dies 24 . If it is desired to continue with the formation of the corrugations, the cycle is repeated. When corrugating a pipe of medium length or intermediate length, the pipe can be cut to the correct size at the end of the corrugation process by conventional pipe cutting devices, such as flying shears (not shown).

The corrugating device described above uses a drive belt or any other drive means to rotate the face plate 30. It has been shown, however, that the face plate can be rotated against the forming wheel 72 by the force of the continuous tube 20 when the drive belt 40 is loosened. The moved past the forming wheel 72 with great force tube 20 exerts a Kreft on daa wheel normal to the plane of the wheel fcus "This

009827/1224 * sau ORIGINAL

Force is the vector sum of a component parallel to the pipe axis 26 and normal to the pipe axis, the normal component causing the end plate 30 to rotate. The speed and the Slope of the corrugations are proportional to the angle of the wheel 72 and can therefore be adjusted by adjusting the angular position of the Form wheel can be changed. When the forming wheel angle is equal to "0", or, in other words, when the forming wheel is on the pipe axis 26 is aligned, a number of longitudinally extending, parallel corrugations or beads are formed.

It can be seen that the above-described. Device 8 allows considerable flexibility when waving. The length of the pipe to be corrugated, the positions of the corrugations and the length of the non-corrugated sections can easily be determined and can be adjusted so that they are suitable for the most varied of applications. the slope and depth of the corrugations can be easily adjusted will.

Claims (18)

Patent claims 1. Device for the continuous formation of alternating corrugated and non-corrugated sections on a pipe. through a head (30), on which a tool (24) for the production of corrugations is attached, a device (22) which the tube (20) axially relative to the Advancing mold (24), a device (40) that provides relative rotational movement between the mold (24) and the Tube (20) generated around the tube axis (26) and by a device (108), which the mold optionally firmly in plant pushes with the tube as the tube moves axially relative to the forming tool. 2. Device according to claim 1, characterized by means (22) for advancing the tube (20) axially relative to the head (30) with the corrugation forming tool (24) mounted on the head firmly engaged with the circumference of the tube can be pressed, and by an actuating device (108 _r 94) that brings the tool for forming the corrugations selectively engaged and disengaged with the tube as the tube continues to move axially relative to the head. 3. Device according to claim 2, characterized in that the device (30, 58) carrying the molding tool (24) is moving of the tool against and away from the pipe and includes a biasing device (94) which normally does the Pulls the forming tool away from the pipe, and that the device which brings the forming tool into engagement and disengagement from the pipe, a mold displacement device (108), which counteracts the biasing device (94) and a movement of the Tool against the pipe over a predetermined distance. 009 827/12 2 U testifies, and that a control device (136) the molding tool displacement device operated in accordance with a predetermined program to adjust the length of the corrugated and non-corrugated Define pipe section. 4. Apparatus according to claim 3> characterized in that the mold support device is attached to the head (30) Contains tool holder (28) with a radially arranged guide track (60) and a tool carrier (69, 62), which is slidably mounted in the guideway that the Forming tool (24) is mounted on the radially inner end of the tool carrier and a first bearing body (84) on its radially outer end is mounted that a second bearing body (98) is mounted on the tool holder (28) next to the first bearing body (84) is that the biasing means (94) normally pulls the tool carrier (62) radially outward, and that the device (108), which brings the forming tool into engagement and disengagement from the tube, has a cam which is mounted so that it can move back and forth between the first and second bearing bodies, with an introduction of the cam between the bearing body presses the tool carrier radially inward against the tube and when the cam is withdrawn the pretensioning device pulls the tool carrier radially outwardly away from the tube. 9827/1224 5. Apparatus according to claim 3,
characterized in that an adjusting device (123) fixes the distance between the tool holder and the pipe axis, that a sliding block (62) is provided within the guide track (60) and is held in this by a spring arrangement (94) which controls the sliding block pulls radially outwards away from the pipe axis, that the sliding block (62) has a recess (64) in its radially inner end, that the tool carrier (69) has a cylindrical shaft (68) which is held in the recess by adjustable clamping means (80) is that the clamping means, when they are in a first position, allow a rotation of the tool carrier (69) about an axis (78) transverse to the pipe axis (26), and when they are in a second position, the tool carrier is fixed in hold the sliding block that a first roller (84) is rotatably mounted on the radially outer end of the sliding block and a second roller (98) is rotatably mounted on the tool holder next to the first roller that the For m tool (24) is a wheel (72) which is rotatably mounted on the radially inner end of the tool carrier, the circumferential shape of the wheel corresponds to the desired contour of the corrugations that are formed by this wheel, and that the device that the molding tool in Brings engagement with the tube, comprises a crook (108) which is hinged reciprocably between the first and second rollers, wherein an introduction of the cam between the rollers presses the tool radially inwardly against the tube and when the cam is withdrawn the Spring assembly (94) pulls the forming tool radially outwardly away from the tube. 0098 2 7/1224 6. Apparatus according to claim 4,
characterized in that the cam (108) has a first constant width section, a second constant width section which is greater than the width of the first section and is spaced therefrom and has a tapered intermediate section, and in that the cam is in a Direction parallel to the pipe axis (26) from a first position in which the first section is located between the rollers, to a second position in which the second section is located between the rollers, and that the difference in width between the the first section and the second section is equal to the desired depth of the corrugation. 7. Apparatus according to claim 3, 5 or 6, characterized., that the head (30) is rotatably mounted about the pipe axis (26), and the actuating device (94/108) is optional brings the tool (24) into engagement and disengagement from the tube (20) to form the corrugations, while the head rotates around the pipe axis and forms helical lines Forms corrugations in the pipe. 8. Device according to one or more of the preceding claims, characterized by a head (30) which is rotatably mounted about a first axis (26), a device (44) which carries the head (30), a device (22) which axially advances the tube (20) relative to the head, the tube axis (26) being coaxial with the first axis (26) runs, a number of equally spaced Tools (24) for the formation of corrugations which can be firmly brought into engagement with the circumference of the pipe, as the head rotates, a support (32) for selectively arranging a desired number of molds (24), which are evenly spaced at the head, and by a device (110), which optionally simultaneously the forming tools engages and disengages the tube as the tube advances axially relative to the head and the head is rotated around the first axis. 9. Apparatus according to claim 8,
characterized, that each mold support device has a tool holder (28), which is mounted on the head and 'each (ie device that engages and disengages the mold from the Brings tube, has a cam (108). ( 10. Device according to claim 9 »
characterized, that each cam (108) is connected at one end to an annular control plate (110), that the control plate is coupled to the head (30) for a common stretching movement and for a movement relative and parallel to the pipe axis, and that a device ( 136) is provided for moving the control plate axially towards and away from the head to move the cams simultaneously between their respective first and second bearing bodies (84, 98). 009827/1224 11. The device according to claim 1, characterized by a system (140), by means of which the pipe (20) can be pressurized, which system has devices (142, 146) for sealing both Ends of the pipe, devices for introducing a pressurized medium into the pipe and pressure control devices (154) to keep the medium pressure within the tube in a predetermined range. 12. The device according to claim 11,
characterized, that the medium is a liquid, and the pressure control device a pressure regulating valve (154), wherein when the tube internal volume during the formation of the corrugations decreases, the pressure regulating valve allows the medium to escape from the pipe. 13. Apparatus according to claim 12,
characterized, that the device to seal at least one end of the tube (20) consists of a plug (142) with a through bore (143), one end of the plug having a diameter which is substantially equal to the inner diameter of the tube and an adjacent reducing shoulder (144), an annular body (146) comprising the plug (142) adjacent the shoulder (144), and means (150) for urging the annular body against one end of the plug, causing the tube to pass through the annular body is deformed against the shoulder and a tight seal is established. 14. Device according to claim 13 » characterized, that the device for introducing the medium is in flow communication with the device passing through the plug (142) Bore (143) is. 009827/1224 15. Apparatus according to claim 13, ' "g e k e η η ζ eii chnet through a device (162) which the. Plug bore (143) closes. 16. Method of making a helical one Corrugation "on the outer surface of a pipe using the device according to claims 1 to 15, characterized by the following steps: a) continuously advancing a pipe axially in with regard to a tool for forming the corrugations, b) generating a relative rotational movement between the pipe and the tool, c) moving the tool against the pipe, the tool moving a portion of the pipe to a predetermined depth presses in over a predetermined period of time and then d) moving the tool away from the pipe, step c) and step d) each being simultaneous with the steps ä) and b) are carried out. 003827/1224 17. The method according to claim 16,
characterized, that a pressure medium is applied to the inside of the tube is done before the tool pushes a section of the pipe and that the pressure inside the pipe is monitored is used to keep the pressure within a predetermined range. 18. The method according to claim 16,
characterized, that the tool for forming the corrugations is set at an angle with respect to the pipe axis on a head which is rotatably mounted about the pipe axis, and that the head is rotated by the fact that the pipe against the forming tool is pressed. ReEu / lo 009827/1224