APPARATUS AND METHOD FOR PRODUCING A PERIPHERAL GROOVE IN AN END PORTION OF A METAL TUBE

Abstract

The invention relates to an apparatus (1) for producing a peripheral groove (101) in an end portion (103) of a metal tube (100), in particular a metal tube (100) which is to be coated on the inside, the groove (101) being set up for receiving tube connectors, having a first, rotationally driven roller (3), a second, freely rotating roller (5), the first roller (3) having a roughened or structured surface (6) relative to the second roller (5), a pressing device (15) for producing a relative movement between the first and second roller (3, 5), between a first and a second position, the rollers (3, 5) assuming a first spacing from one another in the first position, which first spacing permits an introduction of a wall of the tube between the rollers (3, 5), and assuming a smaller, second spacing from one another in the second position, which second spacing is smaller than a material thickness (M) of the wall of the tube.

It is proposed according to the invention that the first, driven roller (3) is set up to grip the tube from the outside in the second position and to rotate it, with the result that a peripheral groove (101) is pressed into the tube in the second position when the first roller (3) is driven.

Claims

1. An apparatus for producing a peripheral groove in an end portion of a metal tube which is to be coated on an inside of the metal tube, the peripheral groove being set up for receiving tube connectors, the apparatus, comprising: a first, rotationally driven roller, a second, freely rotating roller, the first roller having a roughened or structured surface relative to the second roller, and a pressing device for producing a relative movement between the first and second roller, between a first and a second position, the rollers assuming a first spacing from one another in the first position, which first spacing permits an introduction of a wall of the metal tube between the rollers, and assuming a smaller, second spacing from one another in the second position, which second spacing is smaller than a material thickness of the wall of the metal tube, wherein the first, driven roller is set up to grip the metal tube from an outside of the metal tube in the second position and to rotate it such that a peripheral groove is pressed into the metal tube in the second position when the first roller is driven.

2. The apparatus as claimed in claim 1, the apparatus consists of exactly two rollers.

3. The apparatus as claimed in claim 1, wherein the second roller having a greater width than a width of the first roller.

4. The apparatus as claimed in claim 3, wherein the first roller being oriented centrally in the direction of its rotational axis with respect to the second roller.

5. The apparatus as claimed in claim 4, the second roller having, centrally in the direction of its rotational axis, a peripheral recess which is dimensioned such that the first roller presses the tube which is situated between the rollers into the recess in the second position.

6. The apparatus as claimed in claim 5, wherein a width of the recess of the second roller exceeds the width of the first roller such that the first roller and the second roller define a gap with the contour of the peripheral groove in the second position.

7. The apparatus as claimed in claim 1, wherein peripheral edges of the first roller and/or the second roller which are in contact with the tube in the second position being rounded.

8. The apparatus as claimed in claim 1, wherein the pressing device being set up to move the first roller transversely with respect to its rotational axis; or the pressing device being set up to move the second roller transversely with respect to its rotational axis.

9. A method for producing a peripheral groove in an end portion of a metal tube which is to be coated on an inside of the metal tube, the groove being set up for receiving tube connectors, comprising the steps: providing of a first, rotationally driven roller and a second, freely rotating roller in a first position, the rollers assuming a first spacing from one another in the first position, which first spacing permits an introduction of a wall of the metal tube between the rollers, introducing of the wall between the first roller and the second roller, producing of a relative movement between the first and second roller from the first into a second position, in which the rollers assume a smaller, second spacing from one another which is smaller than a material thickness of the wall of the tube, and gripping and rotating of the metal tube by the first driven roller in the second position from an outside of the metal tube such that a peripheral groove is pressed into the metal tube in the second position.

10. The method as claimed in claim 9, comprising the step: pressing of the metal tube which is situated between the rollers in the second position into a recess which runs around on the second roller, in the direction of its rotational axis, by the first roller, into a gap with the contour of the peripheral groove, which gap is defined between the first roller and the second roller in the second position.

11. The method as claimed in claim 10, wherein the relative movement between the first and second roller being produced by movement of the first roller transversely with respect to its rotational axis; or the relative movement between the first and second roller being produced by movement of the second roller transversely with respect to its rotational axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will be described in greater detail in the following text using one preferred exemplary embodiment with reference to the appended figures, in which:

[0025] FIG. 1 shows a diagrammatic side view of an apparatus for generating a peripheral groove in accordance with one preferred exemplary embodiment, and

[0026] FIG. 2 shows a diagrammatic further side view of the apparatus according to FIG. 1.

MODE(S) FOR CARRYING OUT THE INVENTION

[0027] FIG. 1 shows an apparatus 1 for producing a peripheral groove 101 (FIG. 2) in a metal tube 100. The apparatus has a first roller 3 and a second roller 5, the first roller 3 being driven rotationally, whereas the second roller 5 is preferably mounted such that it can rotate freely. The first, driven roller 3 is mounted by means of a first bearing 17, whereas the second roller 5 is mounted by means of a second bearing 11. In the exemplary embodiment which is shown, the first roller 3 is connected to a drive unit 7 by means of a drive means 9, for example a drive chain or a drive belt or toothed belt. In an alternative embodiment which is not shown, the first roller 3 is preferably driven by electric motor, it then being possible for the electric motor to be arranged directly on the housing with the apparatus 1, which housing also carries the bearing 17.

[0028] The freely rotating roller 5 is arranged on a load-bearing structure 13, whereas the first, driven roller 3 is arranged on a pressing device 15.

[0029] As is shown clearly, in particular, from FIG. 2, the pressing device 15 can be moved relative to the load-bearing structure 13. By way of said relative movement, the first, driven roller 3 is moved relative to the second, freely rotating roller 5 transversely with respect to a rotational axis R of the metal tube 100. The first roller 3 can be moved such that it is driven rotationally about a rotational axis A.

[0030] In terms of the width in the direction of the rotational axis A or the rotational axis R of the metal tube 100 or in the direction of the rotational axis F of the freely rotating roller 5, the second roller 5 exceeds the width of the first roller 3. Furthermore, the second roller 5 has a recess 19 on its circumferential face, which recess 19 exceeds the width of the first roller 3 to such an extent that a gap 21 is configured between the first and the second roller 3, 5 when the first roller 3 has moved from a first position into the second position (shown in the figures).

[0031] In the first position (not shown), the first and second roller 3, 5 are spaced apart from one another to such an extent that the metal tube 100 can be guided with its material thickness M between the rollers 3, 5, in order to be arranged with an end portion 103 between the rollers 3, 5. When the tube 100 is arranged correspondingly with its end portion 103, the first roller 3 is moved rotationally and is pressed against the second roller 5 by means of the pressing device 15, with the result that the material of the metal tube 100 is pressed into the gap 21 between the rollers 3, 5, as a result of which a groove 101 is produced on the outside in the end portion 103 of the metal tube.

[0032] The structuring of the surface 6 of the first roller 3 which is necessary for rotating the tube 100 is therefore pressed exclusively onto the outer circumferential face of the tube 100, with the result that the inner face of the tube 100 can remain completely smooth, in particular in the end portion 103, with the exception of the protrusion of the groove 101 into the interior. The subsequent application of a corrosion protection layer or other coating is possible in an unrestricted manner.

[0033] As an alternative to the embodiment which is shown here, it goes without saying that it would also be possible to configure the second roller 5 including the bearing 11 in a height-adjustable manner relative to the load-bearing structure 13, with the result that the metal tube 100 is set rotationally in movement by the first roller 3, but the other force is exerted by the second roller 5.

LIST OF UTILIZED REFERENCE NUMBERS

[0034] 1 Apparatus for producing a peripheral groove

[0035] 3 First, rotationally driven roller

[0036] 5 Second, freely rotatable roller

[0037] 6 Surface

[0038] 7 Drive unit

[0039] 9 Drive means

[0040] 11 Bearing

[0041] 13 Load-bearing structure

[0042] 15 Pressing device

[0043] 17 Bearing

[0044] 19 Recess

[0045] 21 Gap

[0046] 100 Metal tube

[0047] 101 Groove

[0048] 103 End portion

[0049] A, F Rotational axis

[0050] M Material thickness