Crimping Tool

Abstract

A tool for crimping a first part (4) to a second part (5) by pinching a folded margin (6) of the first part against a margin (7) of the second part, the tool including a body (10) to which a wheel (11) is secured to rotate freely about an axis and to move in translation parallel to the axis of rotation, the tool including an alignment element (14) for aligning the wheel on an outer surface (8) of the folded margin.

Description

The present invention relates to a crimping tool for fastening a first part and a second part by pinching a folded margin on the first part against a margin of the second part.

Such a tool generally comprises a body having a wheel secured thereto so as to be free to rotate about an axis. The body is secured to one end of a robot arm so as to be pressed against the folded margin of the first part. The parts are resting on a crimping anvil in such a manner that the folded margin extends parallel to a portion of the anvil that serves to guide the tool.

That requires the parts to be positioned accurately on the crimping anvil. Unfortunately, given the tolerances with which parts are positioned on crimping anvils, it can happen that the folded margin of the part is not accurately aligned with the guide portion of the crimping anvil, so that the crimping tool does not follow exactly the folded margin of the first part. This leads to a defect, which is more particularly inconvenient when the purpose of the crimping is to shape the folded edge into a cord or bead shape of regularity that depends on the displacement direction of the wheel being aligned with the folded margin.

It will therefore be advantageous to have means available for aligning the wheel accurately with the folded margin.

To this end, according to the invention, there is provided a crimping tool for crimping a first part to a second part by pinching a folded margin of the first part against a margin of the second part, the tool comprising a body to which a wheel is secured free to rotate about an axis and to move in translation parallel to the axis of rotation, the tool including an alignment element for aligning the wheel on an outer surface of the folded margin.

Thus, the final positioning of the wheel is provided by the alignment element that serves to keep the wheel in alignment on the folded edge by co-operating with an outer surface thereof.

Other characteristics and advantages of the invention appear on reading the following description of particular, non-limiting embodiments of the invention.

Reference is made to the accompanying drawings, in which:

FIG. 1 is a diagrammatic elevation view of a crimping tool in accordance with a first embodiment of the invention;

FIG. 2 is a view analogous to that of FIG. 1, showing the tool while it is crimping;

FIG. 3 is a diagrammatic view partially in section of a crimping tool in accordance with a second embodiment; and

FIG. 4 is a view analogous to that of FIG. 1 showing a crimping tool in accordance with a variant of the second embodiment of the invention.

With reference to the figures, the invention is described herein concerning a crimping tool given overall reference 1, that is secured to one end 2 of a conventional robot arm 3. The crimping tool 1 is designed to enable a part 4 to be secured relative to a part 5 by pressing a folded margin 6 of the part 4 on a flat margin 7 of the part 5. The parts 4 and 5 in this example are steel sheets. The margin 6 is folded in conventional manner by progressively pressing the margin 6 against the margin 7.

The crimping tool 1 comprises a body 10 having a wheel 11 pivotally mounted thereon.

The wheel 11 has an outer groove 12 axially divided into a section 13 for shaping the folded margin 6 into a bead, and a section 14 for pressing against an outer surface 8 of the fold of the folded margin 6.

The three embodiments differ by the way in which the wheel 11 is mounted on the body 10.

With reference to FIGS. 1 and 2, in the first embodiment, the wheel 11 is mounted to pivot on a pin 15 having one end secured to the body 10. The wheel 11 also mounted on the pin 15 to slide between a first position in which the wheel 11 presses against an adjacent shoulder 16 of the body 10, and a second position in which the wheel is spaced apart from the shoulder 16. The wheel 11 is urged resiliently towards the first position by a spring 17, likewise mounted on the pin 15. The spring 17 is situated beside the section 14 of the groove 12, while the shoulder 16 is situated beside the section 13.

To begin crimping, the crimping tool is brought up to the folded margin 6. During an approach stage, the shoulder 16, against which the wheel 11 is held in abutment, constitutes a stationary reference surface enabling the position of the wheel 11 relative to the robot to be known. The wheel 11 in its first position is brought up to the folded margin 6 at an angle (see FIG. 1) so as to cause its section 14 to press against the outer surface 8 of the folded margin 6 and press the folded margin 6 against the top surface 9 of the margin 7 of the part 5. The wheel 11 is then in an intermediate position between its first and second positions.

The crimping tool 1 is then moved along the general direction of the folded margin 6. During the displacement of the crimping tool 1 along the folded margin 6, the wheel 11 is free to move along the pin 15 between its first and second positions in such a manner that the section 14 remains in contact with the outer surface 8, which thus serves to guide the wheel 11. The co-operation between the section 14 and the outer surface 8 thus ensures accurate alignment of the wheel 11 on the folded margin 6.

With reference to FIG. 3, and in accordance with the second embodiment, the wheel 11 is mounted to rotate on a pin 20 secured to a support 21 that is mounted to slide on the body 10 parallel to the axis 20 between a first position in which the support 21 bears against a reference surface 22 of the body 10, and a second position in which the support 21 is spaced apart from the reference surface 22. The support 21 is mounted to slide on the body 10, e.g. by means of a slideway or a ball-type linear bearing. A spring 23 is interposed between the body 10 and the support 21 to press the support 21 against the reference surface 22.

The wheel 11 in this embodiment is made up of three portions, namely a ring 24 having one end shaped to constitute the section 13, a ring 25, and a washer 26 mounted between the rings 24 and 25, and having one end facing the ring 24 that is shaped to constitute the section 14. The washer 26 and the rings 24 and 25 are interconnected in this embodiment by axial screws 27. The rings 24 and 25 are made of steel, while the washer 26 is made of a material that is softer than that of the rings and than that of the part 4, e.g. out of bronze or of plastics material. In a variant, the material of the rings may be softer than that of the part 4, and/or than that of the washer 26. In certain applications, the washer 26 may be at least as hard as the part 4.

In the variant of FIG. 4, the reference surface 22 of the support 21 bearing against the body 10 when the support 21 is in its first position is constituted by the terminal surface of a screw 28 engaged in the support 21. The screw 28 serves to adjust the position of the wheel 11 when the support 21 is in its first position.

Naturally, the invention is not limited to the embodiments described, and variants can be applied thereto without going beyond the ambit of the invention as defined by the claims.

In particular, the wheel 11 may be made as a single piece or as a plurality of pieces. The wheel 11 may also have other shapes, and for example it may include an outer groove presenting a section that is rectangular.

In the second embodiment, for example, the wheel 11 could be smooth and the alignment element of the wheel 11 could be constituted by a disk fixed on the support 21 in front of the wheel 11 for the purpose of bearing against the outer surface 8.

Claims

1-7. (canceled)

8. A crimping tool for crimping a first part (4) to a second part (5) by pinching a folded margin (6) of the first part against a margin (7) of the second part, the tool comprising a body (10) to which a wheel (11) is secured free to rotate about an axis, wherein the wheel is secured to the body so as to be free also to move in translation parallel to the axis of rotation, and wherein the tool includes an alignment element (14) for aligning the wheel on an outer surface (8) of the folded margin.

9. A crimping tool according to claim 8, wherein the wheel (11) is mounted to slide between two extreme positions, one of which is defined by an abutment (16, 22) having the same orientation as the outer surface, the wheel being urged resiliently towards said position.

10. A crimping tool according to claim 8, wherein the wheel (11) is mounted to move freely in translation along its axis of rotation (15).

11. A crimping tool according to claim 8, wherein the axis of rotation (20) of the wheel (11) is secured to a support (21) mounted to move freely in translation relative to the body (10).

12. A crimping tool according to claim 8, wherein the alignment element comprises a portion (14) of the wheel (11) designed to come into contact with the outer surface (8) of the folded margin (6).

13. A crimping tool according to claim 9, wherein said portion (14) of the wheel (11) is made of a material that is softer than the remainder of the wheel.

14. A crimping tool according to claim 9, wherein said portion (14) of the wheel (11) is made of a material that is softer than that of the first part.