METHOD FOR MOUNTING A PULLEY OF A WINDOW REGULATOR TO A PLASTIC RAIL AND ASSEMBLY OBTAINED

Abstract

The assembly includes a pulley, a plastic rail and a bolt for fixing the pulley to the plastic rail in an axial direction but allowing the pulley to rotate around the bolt. The bolt includes a threaded shaft, a shank, a shoulder, an annular groove, and a head. The assembly further includes a metal sheet with a central hole, such that when inserting the metal sheet through the threaded shaft, which has been previously introduced in a through hole of the plastic rail, the metal sheet contacts partially with a shoulder support base and partially with the plastic rail, such that when the metal sheet is axially compressed against the support base, the hole diameter of the metal sheet becomes smaller than that of the threaded shaft and gets in the annular groove.

Claims

1. An assembly for a window regulator of a vehicle comprising, a plastic rail with a through hole; a pulley with an axial hole; a bolt for fixing the pulley to the through hole in an axial direction but allowing the rotation of the pulley around the bolt, the bolt comprising: a threaded shaft with a diameter Dts smaller than the diameter Dr of the through hole and smaller than the diameter Dp of the axial hole; a head with a diameter Dh greater than the diameter Dp of the axial hole holding the pulley in the axial direction; a shank with a diameter Ds smaller than the diameter Dp of the axial hole such that the pulley can rotate around the shank, but greater than the diameter Dr of the hole, the shank comprising an annular flat base; a shoulder with a diameter Dsh smaller than the diameter Ds of the shank but greater than the diameter of the threaded shaft and smaller than the diameter Dr of the through hole of the plastic rail, the shoulder comprising a support base and an annular groove, between the threaded shaft and the support base of shoulder, with a diameter Dag smaller than the diameter Dts of the threaded shaft, wherein an axial length L of the shoulder is smaller or equal to a thickness W of the plastic rail, such that the annular flat base of the shank rests on a first side of the plastic rail and the support base of the shoulder is aligned with a second side of the plastic rail, opposite to the first side, and wherein the assembly further includes: a metal sheet with a minimum radial length R greater than the diameter Dr of the through hole of the plastic rail such that the plastic rail is fitted between the metal sheet and the annular flat base of the shank, the metal sheet having a central hole with a final diameter Dmsf smaller than the diameter Dsh of the shoulder such that the metal sheet abuts against the support base of the shoulder, the final diameter Dmsf of the central hole being smaller than the diameter Dts of the threaded shaft such that the metal sheet is fitted in the annular groove, and wherein the shape of the metal sheet matches a corresponding shape surrounding the through hole in the second side of the plastic rail, such that the rotation of the metal sheet is impeded.

2. The assembly as in claim 1 wherein the plastic rail comprises a recess in the second side of the plastic rail, surrounding the through hole, for housing the metal sheet, the internal shape of the recess being a non-circular shape.

3. The assembly as in claim 1 wherein the plastic rail comprises a recess in the second side of the plastic rail, surrounding the through hole, for housing the metal sheet, the metal sheet being mounted eccentric with the hole of the plastic rail.

4. The assembly as in claim 1 wherein the metal sheet comprises at least a hole fitted in a protrusion in the second side of the plastic rail.

5. The assembly as in claim 1 wherein the metal sheet comprises at least a lateral wing retained in a hole or protrusion of the plastic rail.

6. The assembly as in claim 1, wherein the support base of the shoulder comprises at least an axial protrusion which is pressed against the metal sheet to prevent the bolt from rotating around the threaded shaft.

7. The assembly as in claim 1 further comprising a vehicle metallic structure and a fixing nut connectable to the threaded shaft for fixing the plastic rail and the pulley to the metallic structure.

8. A method for mounting a pulley of a window regulator to a plastic rail, the method including the following steps: a) providing a through hole in the plastic rail; b) placing the pulley over a first side of the plastic rail with an axial hole of the pulley aligned with the through hole; c) providing a bolt having: a threaded shaft with a diameter Dts smaller than the diameter Dr of the through hole; a shank with a diameter Ds smaller than the diameter Dp of the axial hole such that the pulley can rotate around the shank, but greater than the diameter Dr of the hole and comprising an annular flat base; a shoulder with a diameter Dsh smaller than the diameter Ds of the shank but greater than the diameter Dts of the threaded shaft and smaller than the diameter Dr of the through hole, the shoulder comprising a support base and having an axial length L smaller or equal to a thickness W of the plastic rail; a annular groove, between the threaded shaft and the support base of shoulder, with a diameter Dag smaller than the diameter Dts of the threaded shaft and a head with a diameter Dh greater than the diameter Dp of the axial hole to hold the pulley in the axial direction; d) providing a metal sheet with a minimum radial length R greater than diameter Dr of the through hole, the metal sheet comprising a central hole with an initial diameter Dmsi smaller than the diameter Dsh of the shoulder and greater than the diameter Dts of the threaded shaft (34) and wherein the shape of the metal sheet matches a corresponding shape, surrounding the through hole, in the second side of the plastic rail to prevent the rotation of the metal sheet; e) introducing the bolt through the axial hole and through hole until the annular flat base of the shank rests upon a first side of the plastic rail whilst the shoulder of the bolt remains housed inside the through hole, and the support base of the shoulder remains aligned with a second side of the plastic rail, opposite to the first side; f) inserting the center hole of the metal sheet through the threaded shaft of the bolt until the metal sheet contacts partially with the support base of the shoulder and partially with the second side of the plastic rail; and g) using a suitable pressing tool, applying pressure between the head of the bolt and the metal sheet to deform the metal sheet such that a final diameter Dmsf of central hole becomes smaller than the diameter Dts of the threaded shaft and an edge of the hole of the metal sheet gets fitted in the annular groove of the bolt and the plastic rail gets firmly fitted between the metal sheet and the annular flat base of the shank.

9. The method as in claim 8, further including the step of providing a recess, surrounding the through hole, on the second side of the plastic rail, where the metal sheet is housed in step f), the internal shape of the recess being a non-circular shape and the metal sheet being non circular shaped.

10. The method as in claim 8, further including the step of providing a recess, surrounding the through hole, on the second side of the plastic rail, where the metal sheet is housed in step f), the metal sheet being mounted eccentric with the hole of the plastic rail, to prevent the metal sheet from rotating around the bolt.

11. The method as in claim 8, further includes the step of providing a metal sheet comprising at least a hole which is fitted in step f) in a protrusion in the second side of the plastic rail to prevent the metal sheet from rotating around the bolt.

12. The method as in claim 1 further including the step of providing a metal sheet with at least a lateral wing which is folded and retained in step f) in a hole or protrusion of the plastic rail.

13. The method as in claim 1 further including the step of providing axial protuberances in the support base of the shoulder of the bolt which are pressed against the metal sheet in step g), to prevent the bolt from rotating around the threaded shaft.

14. The method as in claim 1 further including the step of introducing the threaded shaft of the bolt through a hole in a metallic structure of a vehicle and fixing the assembly constituted by the pulley and plastic rail to the metallic structure with a nut.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To complete the description and in order to provide for a better understanding of the disclosure, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the disclosure, which should not be interpreted as restricting the scope of the disclosure, but just as an example of how the disclosure can be carried out. In the figures:

[0036] FIG. 1 is an exploded cross section of all the elements of the fixing assembly of the disclosure;

[0037] FIG. 2 is a cross section of the pulley, bolt and metal sheet of the disclosure mounted on a plastic rail;

[0038] FIG. 3 is an enlarged cross section of the bolt and metal sheet, showing anti-rotating protuberances in the bolt;

[0039] FIG. 4 is a perspective of a rail with a pulley mounted, seen from the first side of the rail; and

[0040] FIG. 5 is a perspective of a rail with a pulley mounted, seen from the second side of the rail.

DETAILED DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 shows an exploded view of the assembly according to the disclosure which comprises:

[0042] A plastic rail 1 with a through hole 11 with a diameter Dr, an a recess 12;

[0043] A pulley 2 with an axial hole 21 with a diameter Dp;

[0044] A bolt 3 comprising a head 31 with a diameter Dh, a shank 32 with a diameter Ds, a shoulder 33 with a diameter Dsh, a threaded shaft 34 with a diameter Dts and an annular groove 35 with a diameter Dag;

[0045] A metal sheet 4 with central hole 41 with an initial diameter Dmsi and a final diameter Dmsf, Dmsi being greater than Dmsf. After cold pressing the metal sheet 4 can expand and the initial diameter Dmsi of the central hole becomes a final diameter Dmsf smaller than Dmsi;

[0046] A nut 5.

[0047] As can be seen in FIG. 1 Dh>Ds>Dsh>Dts>Dag. Dh is greater than Dp so that when the bolt 3 is introduced through the axial hole 21 of the pulley 2 the head 31 blocks the movement of the pulley 2 in the axial direction, but the pulley can rotate around the shank 32 because Ds is (slightly) smaller than Dp. This can be seen in FIG. 2.

[0048] Dsh is smaller than Ds so that an annular flat base 321 (orthogonal to the axis direction of the shaft) is formed between them and such that, when the bolt 3 is introduced through the hole 11 of the plastic rail 1, the annular flat base 321 of the shank 32 rests upon a first surface (the upper surface as represented in FIG. 2) of the plastic rail 1 and prevents the bolt 3 from passing completely through the hole 11 of the plastic rail 1.

[0049] Dts is smaller than Dsh so that a support base 331 (orthogonal to the axis direction of the shaft) is formed between them and the axial length L of the shoulder 33 is equal to the thickness W of the plastic rail 1 such that, when the bolt 3 is introduced through the hole 11 of the plastic rail 1, the support base 331 of the shoulder 33 is aligned with a second surface (the bottom surface as represented in FIG. 2) of the plastic rail 1, opposite to the first surface.

[0050] Dmsi is greater than Dts but smaller than Dsh, such that when inserting the metal sheet 4 through the threaded shaft 34 (which is already introduced in the hole 11 of the plastic rail 1) the metal sheet 4 partially contacts with the support base 331 of the shoulder 33 and partially with the plastic rail 1.

[0051] The metal sheet 4 shown in FIG. 5 has a non-circular external shape such that the metal sheet 4 fits in the recess 12 of the second side of the plastic rail 1 and prevents the metal sheet 4 from rotating around the bolt 3. In FIG. 5 the external shape of the metal sheet 4 is hexagonal and the recess 12 is also hexagonal. Obviously the shape of the metal sheet 4 can be square, pentagonal, octagonal or any other non-circular shape as long as the recess 12 has a similar shape in which the metal sheet 4 fits without possibility of rotating.

[0052] Dag is smaller than Dts and smaller than Dmsi but when a pressing force is applied between the head 31 and the metal sheet 4, a radial deformation (expansion) of the metal sheet 4 will provoke that the edges of the hole 41 of the metal sheet 4 enter into the annular groove 35 thus preventing the axial movement of the bolt 3 (the diameter of the central hole is reduced such that the final diameter Dmsf of the center hole is smaller than Dts). At the same time, as shown in FIGS. 2 and 3, the plastic rail 1 gets firmly fitted between the outermost part of the metal sheet 4 and the annular flat base 321 of the shank 32.

[0053] As shown in FIG. 3, the support base 331 of the shoulder 33 comprises ribs 332 which are pressed against the metal sheet 4 preventing the rotation of the metal sheet 4 in relation to the bolt 3.

[0054] A nut 5 permits the fixing of the assembly (rail 1, pulley 2, bolt 3 and metal sheet 4) to a metallic structure 6 of a vehicle door.

[0055] According to the disclosure the mounting steps will be as follows:

[0056] a) placing the pulley 2 over a first side of the plastic rail 1 with the axial hole 21 of the pulley aligned with the through hole 11 of the plastic rail 1;

[0057] b) introducing the bolt 3 through the axial hole 21 and through hole 11 until the annular flat base 321 of the shank 32 collides and rests upon the first side of the plastic rail 1 whilst the shoulder 33 remains housed inside the through hole 11 and the support base 331 of the shoulder 33 remains aligned with the second side of the plastic rail 1. The threaded shaft 34 protrudes from the second side of the plastic rail 1 opposite to the first side;

[0058] c) inserting the metal sheet 4 through the threaded shaft 34 of the bolt 3 until the metal sheet 4 is placed inside the recess 12 of the plastic rail 1, remaining the metal sheet 4 partially in contact with the support base 331 of the shoulder 33 of the bolt 3 and partially in contact with the second side of the plastic rail 1;

[0059] d) using a suitable pressing tool, applying pressure between the head 31 of the bolt 3 and the metal sheet 4 to deform the metal sheet 4 pushing the edges of the hole 41 of the metal sheet 4 into the annular groove 35 of the bolt 3. Simultaneously the plastic rail 1 gets compressed between the metal sheet 4 and the annular flat base 321 of the shank 32. Thus, metal sheet 4, plastic rail 1, and bolt 3 (and pulley 2) are firmly fixed between them with no possibility of relative axial movement.

[0060] As a result of the mounting process an assembly as shown in FIG. 2 is obtained.

[0061] Further, the assembly obtained in step d) can be attached to a metallic structure (for example of a vehicle door) by means of a nut 5, screwed to the threaded shaft.

[0062] The disclosure is not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the disclosure.