Device for rolling a circumferential groove in a pipe

Abstract

A device for forming a circumferential groove in a pipe comprises drive roller, rotatably suspended around a first rotation axis for driving the pipe, and a groove roller, rotatably suspended around a second rotation axis offset in a offset direction from the first rotation axis for forming the circumferential groove. The first rotation axis and the second rotation axis are tilted at a misalignment angle with respect to each other, in particular around the offset direction.

Description

[0001] Title: Device for rolling a circumferential groove in a pipe

[0002] TECHNICAL FIELD

[0003] The invention relates to a device and method for rolling a circumferential groove in a pipe.

[0004] BACKGROUND

[0005] Groove roll machines can be employed to manufacture a groove in a pipe by rolling and pressing the pipe wall to a smaller diameter. In other words, the machine does not remove material but plastically deforms the pipe wall.

[0006] Typically, this is performed by placing the pipe over a drive roller that rotates the pipe, and by radially moving a groove roller towards the pipe to form the groove as the pipe is rotated.

[0007] SUMMARY

[0008] It has been observed that when using a groove roll machine, during the forming process, forces may be induced which axially displace the pipe away from the machine, e.g. off the drive roller. As such, holding means are required to prevent or reduce axial movement of the pipe away from the machine, or an operator has to manually hold the pipe in place while forming the groove.

[0009] It is an object of the present invention to limit axial displacement of the pipe during groove rolling, preferably without requiring mechanical holding means and / or less complicated holding means and / or an operator holding the pipe in place.

[0010] In summary, aspects of the invention relate to a device and method for forming a circumferential groove in a pipe, which pipe may for example be used in a sprinkler system. The device comprises a drive roller and a groove roller.

[0011] The device roller is rotatably suspended around a first rotation axis and arranged for extending into the pipe in an axial direction. The drive roller has a peripheral drive surface to be engaged with an inner wall of the pipe for rotating the pipe generally about the centreline of the pipe. The drive roller typically further comprises a groove adjacent the peripheral drive surface into which the pipe can be forced, for forming the groove in the pipe. Preferably, any device comprises a driving unit, such as an electric motor, for rotating the device roller about the first rotation axis.

[0012] The groove roller is rotatably suspended around a second rotation axis offset from the first rotation axis in an offset direction. The groove roller has a peripheral form surface to be pressed onto the pipe while the pipe is driven, for thereby forming the circumferential groove. The peripheral form surface generally extends radially relative to the second rotation axis. In use, the peripheral form surface is axially aligned with the groove in the drive roller, and moved towards the drive roller relative to the drive roller, with the pipe positioned between the peripheral form surface and the groove in the drive roller.

[0013] When the second rotation axis is positioned above the first rotation axis, the offset direction can be parallel to gravity. Alternatively, the offset direction can conceivable be at any angle relative to gravity. In general, the offset direction may be regarded orthogonal to the first rotation axis.

[0014] The inventor has found that when the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted with respect to each other at a misalignment angle, axial displacement of the pipe during rolling of the groove is prevented or at least limited, compared to the known groove rolling device in which the first rotation axis and the second rotation axis are essentially aligned. Thus, advantageously, axial displacement (or “walking”) of the pipe during rolling of the groove therein may be limited or prevented, preferably without providing additional retaining elements for mechanically retaining the pipe in position, without applying a complex control strategy for actuating the drive roller and groove roller, and / or without requiring a manual axial force to be applied by a worker to retain the axial position of the pipe on the drive roller.

[0015] For any device disclosed herein, the first rotation axis of the drive roller and the second rotation axis of the groove roller are in use of the device tilted at the misalignment angle about the offset direction. When the offset direction is generally vertical, the misalignment is visible in a top view of the device. The first rotation axis can in general be tilted clockwise or counterclockwise about the offset direction relative to the second rotation axis.

[0016] It has been observed that when the misalignment angle is between 0.1 and 10 degrees, 5 degrees or smaller, 2 degrees or smaller, preferably between 0.5 and 1.0 degrees, the pipe essentially remains in place relative to the drive roller in the axial direction while forming the groove.

[0017] Preferably, when regarded in a direction parallel to the first rotation axis, the drive roller is rotated clockwise and the misalignment angle is in a counter-clockwise direction relative to the offset direction, or the drive roller is rotated counter-clockwise and the misalignment angle is in a clockwise direction relative to the offset direction.

[0018] Preferably, when viewed in a direction parallel to the offset direction, the first rotation axis and the second rotation axis intersect at a midplane of the peripheral form surface and / or at a midplane of the groove formed in the pipe. The midplane may be defined as the centre when regarded in the axial direction. In this way, besides counteracting the axial force the misalignment angle may not induce other forces or torques on the pipe.

[0019] The first rotation axis and the second rotation axis are preferably parallel to each other when the device is regarded in a direction perpendicular to the offset direction, for example in a side view when the offset direction is oriented parallel to gravity. In other words, the first rotation axis may be provided on a first plane, the second rotation axis may be provided on a second plane at a radial offset from the first plane, and the first and second planes may be parallel to each other.

[0020] For any device disclosed herein, the groove roller and the drive roller may be arranged for cooperatively suspending the pipe in a cantilevered fashion. That is, besides the groove roller and the drive roller, the pipe is not supported by additional means such as auxiliary rollers along the axial length of the pipe. As such, the present invention can be applied to relatively short pipes, of which the axial length is insufficient to accommodate support by said additional means.

[0021] For any device disclosed herein, the groove roller may be driven by the drive roller, via the pipe. Thus, the groove roller may be a passive roller to reduce the complexity of the device that would be caused by additional actuators and complex control algorithms for synchronizing the groove roller with respect to the drive roller.

[0022] Preferably, to provide the groove in the pipe with a certain depth, the groove roller is displaceable along the offset direction relative to the drive roller. The positioning of the groove roller may be controllable using an electric actuator.

[0023] Any device disclosed herein may further comprise an adjustment mechanism arranged for adjusting the misalignment angle around the offset direction between the first rotation axis and the second rotation axis.

[0024] A further aspect of the invention relates to a method of rolling a circumferential groove into a pipe, the method comprising the steps of: positioning the pipe onto a peripheral drive surface of a drive roller, which drive roller is rotatably suspended around a first rotation axis; pressing a peripheral form surface of a groove roller onto the pipe towards a groove in the drive roller, which groove roller is rotatably suspended around a second rotation axis offset from the first rotation axis in an offset direction; and rotating the pipe relative to the groove roller, thereby forming the groove into the pipe; wherein the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted at a misalignment angle relative to each other.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention will be further elucidated in the figures:

[0027] FIG 1 illustrates an embodiment of a device as described herein;

[0028] FIG 2 provides a detailed side view of the device described herein;

[0029] FIG 3 illustrates a schematic top view of the device described herein.

[0030] DETAILED DESCRIPTION

[0031] The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. In the drawings, the absolute and relative sizes of systems, components, layers, and regions may be exaggerated for clarity. Embodiments may be described with reference to schematic and / or crosssection illustrations of possibly idealized embodiments and intermediate structures of the invention. In the description and drawings, like numbers refer to like elements throughout. Relative terms as well as derivatives thereof should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the system be constructed or operated in a particular orientation unless stated otherwise. FIGs 1 to 3 illustrates exemplary embodiments of a device 100 for forming a circumferential groove 55 in a pipe 50. The device 100 comprises a drive roller 110 and a groove roller 120.

[0032] The drive roller 110 is rotatably suspended, e.g. to a frame of the device 100, around a first rotation axis 111 and arranged for extending into the pipe 50 in an axial direction 101. The drive roller 110 has a peripheral drive surface 112 to be engaged with the pipe 50 for rotating the pipe 50, and a groove 130 into which the pipe 50 can be forced to form the groove 55 into the pipe 50.

[0033] The groove roller 120 is rotatably suspended around a second rotation axis 121 offset from the first rotation axis 111 in an offset direction 103, e.g. perpendicular to the axial direction 101 and a transverse direction 102. The groove roller 120 can e.g. be suspended to the same frame as the drive roller, or to a separate frame. The groove roller 120 has a peripheral form surface 122 to be pressed onto the pipe 50 while the pipe 50 is driven, thus inducing a radial force FR on the pipe 50, for thereby forming the circumferential groove 55 therein. The groove roller 120 may be displaceable along the offset direction 103 towards and / or away from the pipe, to adjust the groove depth of the groove 55. As a particular example, the groove roller 120 can be swivelled towards the pipe over a swivel axis parallel to the second rotation axis. The radial force FR allows the groove roller 120 to be driven passively by the drive roller 110, via the pipe 50.

[0034] When the drive roller is rotated in a first rotation direction, for example clockwise, the groove roller can be swivelled in a second rotation direction opposite to the first rotation direction, for example counterclockwise.

[0035] As for example depicted in FIG 2, the groove roller 120 and / or the drive roller 110 can be supported only from a single side, in a cantilever fashion. As illustrated, the groove roller 120 and the drive roller 110 are arranged for cooperatively suspending the pipe 50 in a cantilevered fashion. That is, besides the groove roller 120 and the drive roller 110, the pipe 50 does not have to be supported or held in place by additional retaining means such as auxiliary rollers along the axial length of the pipe. As such, the present invention can be applied to relatively short pipes.

[0036] It has been observed that when the first rotation axis 111 and the second rotation 121 are essentially parallel to each other, as is the aim in known groove rollers, an axial force FA on the pipe 50 drives the pipe 50 away from the device 100 in the axial direction 101. To counter this axial force FA, for example, in the known device, an operator was required to hold the pipe, creating a potential hazardous situation with the hands of the operator near the rotating parts of the device.

[0037] The inventor has found that, according to the present disclosure, when the first rotation axis 111 and the second rotation 121 are misaligned, the axial force FA previously present is negated and it is no longer required to hold the pipe while forming the groove in the pipe. In other words, the pipe stays in place in the axial direction 101 while forming the groove. Where previously some length of the pipe had to axially extend further than the drive roller to hold the pipe in place, with the device according to the present disclosure, such an extending pipe section is no longer essential and a groove can be formed in shorter lengths of pipe.

[0038] As shown in FIG 2, the inner diameter of the pipe can be larger than the outer diameter of the peripheral drive surface 112. Adjacent the peripheral drive surface 112, a peripheral groove 130 is formed in the drive roller 110 into which material of the pipe 50 is forced to form the groove into the pipe 50. A width in axial direction of the peripheral groove 130 can be essentially equal to or larger than the width of the peripheral form surface 122 of the groove roller 120. The first rotation axis 111 of the drive roller 110 and the second rotation axis 121 of the groove roller 120 are tilted with respect to each other at a misalignment angle A around the offset direction 103, to counteract the axial force FA and prevent or at least reduce axial displacement (or “walking”) of the pipe during the rolling of the groove.

[0039] The misalignment angle can for example be between 0.1 and 2 degrees, preferably between 0.5 and 1 degrees, although larger misalignment angles are also envisioned. The misalignment angle A may be adjusted, e.g. by an adjustment mechanism.

[0040] Preferably, when viewed in the offset direction 103, as for example shown in FIG 3, the first rotation axis 111 and the second rotation axis 121 intersect at a midplane 56 of the peripheral form surface 122, thus a midplane of the groove 55 formed in the pipe 50. In this way, besides counteracting the axial force FA, the misalignment angle A may not induce other relevant forces or torques on the pipe 50. For the same reason, the first rotation axis 111 and the second rotation axis 121 are preferably parallel to each other when regarded in the axial direction 101.

[0041] In the side view of FIG 2, it can be seen that preferably, the first rotation axis 111 and the second rotation axis 121 are oriented horizontally, and thus parallel when regarded in the side view. In the top view of FIG 3 the preferred misalignment between the first rotation axis 111 and the second rotation 121 becomes visible.

[0042] Also depicted in the side view of FIG 2, the peripheral form surface of the groove roller is typically axially offset relative to the peripheral drive surface of the drive roller. In particular, the peripheral form surface is axially closer to a distal end 51 of the pipe than the peripheral drive surface.

[0043] The invention applies not only to manufacturing applications where the device is applied for rolling a circumferential groove in a pipe, but also to other technical, agricultural or industrial applications where groove rolling is performed. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which may be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and can be within the scope of the invention. In the claims, any reference signs shall not be construed as limiting the claim.

[0044] The terms 'comprising' and including’ when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus expression as 'including' or ‘comprising’ as used herein does not exclude the presence of other elements, additional structure or additional acts or steps in addition to those listed. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may additionally be included in the structure of the invention without departing from its scope.

[0045] Expressions such as: "means for ...” should be read as: "component configured for ..." or "member constructed to ..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the invention. To the extent that structure, material, or acts are considered to be essential they are inexpressively indicated as such. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the scope of the invention, as determined by the claims.

Claims

CLAIMS1. A device for forming a circumferential groove in a pipe, comprising: a drive roller, rotatably suspended around a first rotation axis and arranged for extending into the pipe in an axial direction, wherein the drive roller has a peripheral drive surface to be engaged with an inner wall of the pipe for rotating the pipe; and a groove roller, rotatably suspended around a second rotation axis offset from the first rotation axis in an offset direction, wherein the groove roller has a peripheral form surface to be pressed onto the pipe while the pipe is rotated, for thereby forming the circumferential groove; wherein the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted at a misalignment angle relative to each other.

2. The device according to claim 1, wherein the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted at the misalignment angle about the offset direction between the first rotation axis and the second rotation axis.

3. The device according to claim 1 or 2, wherein the offset direction is parallel to gravity.

4. The device according to any preceding claim, wherein the misalignment angle is between 0.1 and 2 degrees.

5. The device according to claim 3, wherein the misalignment angle is 0.5 degrees.

6. The device according to any preceding claim, wherein the first rotation axis and the second rotation axis intersect in a midplane of the peripheral form surface when regarded in a direction parallel to the offset direction.

7. The device according to any preceding claim, wherein the first rotation axis and the second rotation axis are oriented parallel and essentially horizontally.

8. The device according to any preceding claim, wherein the drive roller and the groove roller are arranged for cooperatively suspending the pipe in a cantilevered fashion.

9. The device according to any preceding claim, further comprising a driving unit for rotating the drive roller about the first rotation axis.

10. The device according to any preceding claim, further comprising an adjustment mechanism arranged for adjusting the misalignment angle around the offset direction between the first rotation axis and the second rotation axis.

11. A method of rolling a circumferential groove into a pipe, the method comprising the steps of: positioning the pipe onto a peripheral drive surface of a drive roller, which drive roller is rotatably suspended around a first rotation axis;pressing a peripheral form surface of a groove roller onto the pipe towards a groove in the drive roller, which groove roller is rotatably suspended around a second rotation axis offset from the first rotation axis in an offset direction; and rotating the pipe relative to the groove roller, thereby forming the groove into the pipe; wherein the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted at a misalignment angle relative to each other.

12. Method according to claim 11, wherein the first rotation axis of the drive roller and the second rotation axis of the groove roller are tilted at the misalignment angle about a generally vertical axis.

13. Method according to claim 11 or 12, wherein when regarded in in a direction parallel to the first rotation axis, the drive roller is rotated clockwise and the misalignment angle is in a counterclockwise direction about the offset direction, or the drive roller is rotated counter-clockwise and the misalignment angle is in a clockwise direction about the offset direction.

14. Method according to any of the claims 11-13, wherein a centreline of the pipe is oriented essentially parallel to the first rotation axis.

15. Method according to any of the claims 11-14, wherein the peripheral form surface of the groove roller is axially offset relative to the peripheral drive surface of the drive roller.

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