GB2412704A

GB2412704A - Adjustable fastening device

Info

Publication number: GB2412704A
Application number: GB0407058A
Authority: GB
Inventors: Paul Antony Crees; Philip Sanders
Original assignee: Hella Manufacturing Ltd
Current assignee: Hella Manufacturing Ltd
Priority date: 2004-03-29
Filing date: 2004-03-29
Publication date: 2005-10-05
Also published as: GB0407058D0

Abstract

A fastening device is used for fastening a first component, such as a car to a second component, such as a rear light cluster such that the separation between the first and second components is adjustable. The fastening device comprises an adjuster collar (21) fitted in an elongate stud (12) via a thread. Rotation of the adjuster collar (21) moves the adjuster collar (21) axially along the stud (12). An attachment collar (24) is mounted on the adjuster collar (21) . The attachment collar (24) attaches to the first component, in use, and a threaded portion of the stud (12) attaches to the second component, in use.

Description

r 24 1 2704 FASTENING DEVICE, USE THEREOF AND FASTENED ASSEMBLY The

present invention relates to a fastening device. It also relates to the use of the fastening device and a fastened assembly. Particularly, but not necessarily exclusively, the invention relates to the fastening of ancillary components to a vehicle, e.g. fastening of a rear light cluster to a car.

It is known to fasten an assembly of lights (usually referred to as a light cluster) to a car body in the following way. An elongate stud is first fixed to the light cluster. The remainder of the stud projects from the cluster. This projecting portion is inserted into a fixing hole in the car body at the desired location. A nut and washer is threaded onto a thread formed on the projecting portion and tightened to fix the projecting portion, and therefore the light cluster, to the car body.

Modern car design requires the outline shape of the car to be smooth. For this reason, the light clusters are usually attached to be flush with the car body, perhaps with a predetermined small gap between them.

However, it is difficult to produce a car body that has precisely the correct geometry so that a fixed length fastening device can be used to provide the correct spacing between the light cluster and the car body.

The inventor has realised that it is possible to provide a modification of known fastening devices that allows adjustment of the separation of the car body and the light cluster, but this requires that the nut holding the car body to the fastening device is undone and repositioned (e.g. against the urging of a spring) and re-tightened. This is inconvenient, and can give only coarse adjustability of the separation.

In order to address or ameliorate at least one of the problems identified above, the inventor has devised the present invention. However, the inventor realises that the invention may have more general applicability that the attachment of a light cluster to a car body, and may more generally be used to fasten a first component with respect to a second component.

In a general aspect, the present invention provides adjustment means for adjusting the separation of first and second components, the adjustment means being independent of the attachment of the first and second components to first and second attachment means of the fixing device.

The independence of the adjustment means allows the separation of the first and second components to be adjusted without loosening of the attachment between the first and second components and the fixing device.

Preferably, in a first aspect, the present invention provides a fastening device for fastening a first component to a second component, having first attachment means for attachment to the first component, second attachment means for attachment to the second component, and adjustment means, wherein the position of the first attachment means is adjustable relative to the position of the second attachment means via the adjustment means so that, in use with the first component fixedly attached to the first attachment means and the second component fixedly attached to the second attachment means, the separation of the first and second components is adjustable.

Preferably, in a second aspect, the present invention provides a fastened assembly of a first component and a second component, attached via a fastening device to give a predetermined separation between the first and second components, wherein the fastener includes adjustment means for adjusting the position of the first and/or second component on the fastening device, thereby allowing adjustment of the separation between the first and second components independent of the grip between the components and the fastening device.

Preferably, in a third aspect, the present invention provides a fastened assembly of a first component and a second component, attached via a fastening device according to the first aspect, the assembly allowing adjustment of the separation between the first and second components independent of the grip between the components and the fastening device.

Typically, the first component is an automobile body and the second component is an automobile component, such as a light cluster.

The fastened assembly may include one or more further fastening devices according to the first aspect, the assembly thereby allowing adjustment of the separation between the first and second components by adjustment of each fastening device.

Preferably, the fastening devices are arranged relative to the first and second components such that adjustment of the fastening devices allows adjustment of the attitude of the second component with respect to the first component. For example, the tilt of the second component with respect to the first component may be adjusted in this way.

Preferably, in a fourth aspect, the present invention provides a use of a fastening device according to the first aspect to fasten a first component to a second component, the use including the step of adjusting the separation of the first and second components by operation of the adjustment means to alter the position of the first attachment means relative to the position of the second mounting means when the first component is fixedly attached to the first attachment means and the second component is fixedly attached to the second attachment means.

Preferably, in a fifth aspect, the present invention provides an automobile component fastening device according to the first aspect, wherein the first component is an automobile body.

The features set out below are preferred, optional or typical features. Unless otherwise specified, or the context demands otherwise, they are applicable to any of the aspects of the invention set out above. The features below may be combined with each other and/or with any s combination of the above aspects.

Preferably, the first attachment means is moveable on the fastening device by operation of the adjustment means. Thus, the second attachment means may remain fixed with respect to the fastening device and the second component. Typically, the first attachment means attaches to the first component by compressing a portion of the first component between opposing surfaces. For example, the compression of the opposing surfaces of the first attachment means may be provided by a nut member for mounting on a threaded portion of the first attachment means.

Preferably, at least one of the opposing surfaces of the first attachment means includes a rough portion to assist in frictional engagement of the first attachment means with the first component. Thus, when the adjustment means is operated with the first and second components fastened, the first attachment means may remain in position with respect to the first component.

This can ensure that the first component remains securely fastened to the first attachment means and therefore any compromise of the mechanical integrity of the attachment between the first component and the second component can be avoided. Most preferably, the rough portion is formed annularly around one of the opposing surfaces.

Preferably, the adjustment means is mounted on a first threaded length of the device, its position on the device being alterable by turning of the adjustment means along the threaded portion. The position of the threaded length of the device may be fixed with respect to the second attachment means, thereby allowing the second attachment means and therefore the second component to remain fixed in position with respect to the fastening device.

Preferably, the adjustment means includes an adjustment collar engaged on the threaded length of the device. Typically, the internal thread of the collar is tapped by the threaded length of the device. Usually, the collar is mounted only once on the threaded length of the device, so the self-tapping arrangement can allow a tight fit to be formed between the adjustment collar and the threaded length.

Typically, the collar has a driving portion for engagement with a driving means for positioning the collar along the threaded length of the device. The driving portion may, for example, be a nut portion such as a hexagonal nut portion. The driving portion is typically at one end of the collar, preferably at the end of the collar distal from the second attachment means.

Preferably, the collar has a mounting portion on which the first attachment means can be mounted, or is mounted. The mounting portion may have at least one resilient stop (preferably there are two or more resilient stops) formed at the leading end of the collar for allowing positive location of one end of the first mounting means on the collar.

Preferably, the resilient stop is formed in the shape of a barb, allowing location of the first attachment portion on the collar but resisting against its removal by abutting against the leading end of the first attachment means. Typically, each resilient stop is urged outwardly further to help to retain the first attachment portion on the collar when the collar is located on the threaded length of the device. The resilient stop can help to provide clickable locking together of the first attachment means and the adjustment collar. This can assist the easy assembly of the lO fastening device.

Preferably, the adjustment collar mounting portion includes a flange positioned to locate the other end of the first attachment means on the collar. This other end of the first attachment means is distal from the leading end. Typically, the flange is bevelled so that, with the first attachment means located on the mounting portion of the collar, the flange bears compressively against the first attachment means.

Preferably, the mounting portion further includes a chamfered step adjacent the flange. This can assist in the clickable positive location of the first attachment means on the collar.

Preferably, the mounting portion includes at least one projection on its outer surface for frictional engagement with the internal surface of the first attachment means. More preferably two, three or four such projections are provided. Typically, the projections are ribs. The ribs may be formed in line with the longitudinal axis of the collar. The advantage of using such projections is that the degree of frictional engagement with the internal surface can be tuned more easily by altering the shape of these projections than by altering the diameter of the entire mounting portion.

Preferably, the second attachment means of the fastening device includes a second threaded length of the device for engagement with the second component, e.g. by self-tapping engagement. Typically, the first and second threaded length of the device are formed on a single shaft on a common axis. The first and second threads may, for example, be separated by a flange. In use, the flange may abut with the second component to define the location of the second component on the fastening device.

Preferably, at the end of the shaft distal from the second threaded length is a drive head for driving the attachment of the second attachment means (e.g. the second threaded length) to the second device. This drive head may be any convenient drive head such as a tore drive.

Preferably, the torque required to turn the adjuster collar with respect to the threaded length of the device is greater than the torque required to turn the first attachment means with respect to the adjuster collar. In this way, when the adjuster collar is turned to adjust its position along the threaded length of the device, the turning of the adjuster collar does not turn the first attachment means. The advantage of this is that the adjustment of the position of the adjuster means may not affect the tightness of the attachment between the first attachment means and the first component.

Preferably, the adjuster collar is formed of a dissimilar material to the material of the threaded S length. For example, the material of the threaded length may be a metal, e.g. stainless steel. The material of the adjuster collar may be a plastics material, e.g. nylon. Forming the adjuster collar of a softer material than the material of the threaded length allows the adjuster collar to be tapped by the threaded length, allowing a tight fit to be formed between them.

Preferably, the adjustment means (and thus preferably the first attachment means) is located at a predetermined distance from the second attachment means, thereby defining a predetermined tolerance for adjustment of the relative positions of the first and second components, in use. Typically, the adjustment means is located at or close to its limit on the device distal from the second attachment means. The advantage of this is that the separation between the first and second components is maximized when the fastening device is first used to fasten the first and second components, to avoid clashing of the first and second components during the fastening step. Then, the separation between them can be reduced to the required separation by operation of the adjustment means, as necessary.

Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a schematic perspective view of a fastening device according to an embodiment of the invention.

Fig. 2 shows an enlarged schematic partial longitudinal sectional view of the fastening device of Fig. 1.

Fig. 3 shows the fastening device of Fig. 2 with the attachment collar and adjuster collar removed.

Fig. 4 shows a schematic perspective view of the lO attachment collar shown on the fastening device of Fig. 2.

Fig. 5 an enlarged schematic longitudinal sectional view of the attachment collar of Fig. 4.

Fig 6 shows an enlarged schematic perspective view of the adjuster collar shown on the fastening device of Fig. 2.

Fig. 7 shows a schematic side view of the adjuster collar shown in Fig. 6.

Fig. 8 shows a schematic side view of the adjuster collar shown in Fig. 6, viewed from a direction perpendicular to the viewing direction of Fig. 7.

Fig. 9 shows an axial sectional view along the line C-C in Fig. 8.

Fig. 10 shows a longitudinal sectional view along the line A-A in Fig. 8.

Fig. 11 shows a longitudinal sectional view along the line B-B in Fig. 8.

Fig. 12 shows an enlarged view of the region marked "Detail S" in Fig. 10.

Fig. 13 shows an enlarged view of the region marked "Detail R" in Fig. 11.

Fig. 1 shows a fastening device 10 according to an embodiment of the present invention. In Fig. 1, the fastening device is assembled and ready for use to fasten a first component (not shown) to a second component (not shown).

Fig. 2 shows the fastening device of Fig. 1 in more detail. In Fig. 2, a central elongate stud 12 (shown on its own in Fig. 3) has a first threaded length JO 14 and a second threaded length 16. The pitch of the second threaded length is relatively coarse. Second threaded length 16 is intended for attachment to a second component such as a rear light cluster for a car by screwing into a hole in said second component and self tapping said hole for a secure fit. Flange 18 is provided to limit the progress of the stud 12 into the second component and to allow the tight fit of the second threaded length inside the self-tapped hole in the second component. Second threaded length 16 is driven into the second component via drive head 20, shown as a tore drive head, but which can be any convenient drive head.

An adjuster collar 21 is fitted onto first threaded length 14. First threaded length 14 has a finer pitch than second threaded length 16. The adjuster collar is formed from nylon and is tapped by the first threaded length on mounting on the first threaded length.

The position of the adjuster collar on the first threaded length may therefore be altered by turning the adjuster collar with respect to the first threaded length, and therefore with respect to the elongate stud 12 as a whole.

For the purpose of turning the adjuster collar with respect to the stud, a drive head 22 is provided. In this embodiment, the drive head 22 has a standard S hexagonal nut shape, of a suitable size.

An attachment collar 24 is mounted on a mounting portion of the adjuster collar 21. The attachment collar 24 has an elongate cylindrical part 25 (see Figs. 4 and 5) with an outwardly extending flange 26 formed at the JO end of the cylindrical part closest to flange 18. A thread is formed on the outer surface of the cylindrical part for mounting a nut and washer (not shown) for holding the attachment collar 24 with respect to a first component (not shown) such as a car body.

In use, the fastening device 10 is first fastened to the second component (e.g. the rear light cluster) and then fastened to the first component (e. g. the car body) by passing the elongate cylindrical part 25 of attachment collar 24 through a suitably-sized hole in the car body and then mounting and tightening a nut and washer arrangement on the cylindrical part to compress a part of the car body adjacent the hole between a surface of the washer and surface 28 of flange 26, thereby holding the fastening device (and thus the second component) with respect to the first component.

As shown in Figs. 4 and 5, the internal surface of the attachment collar 24 is not threaded but is smooth.

It is this surface of the attachment collar that is mounted on the adjuster collar 21.

Adjuster collar 21 is shown in greater detail in Figs. 6-13. Note that, in these drawings, the adjuster collar is facing in the opposite direction to the direction shown in Figs. 1 and 2.

Adjuster collar 21 includes a drive head 22, as described above, and a mounting portion for holding the attachment collar 24. The mounting portion has, in order along the adjuster collar from the drive head, a bevelled flange 30, a chamfer 32, a ribbed portion 34 and a sprung JO barb portion 36 at the end of the adjuster collar distal from the drive head 22. The adjuster collar 21 is formed in one piece from nylon, but may be formed from other suitable plastics materials.

Fig. 7 shows the adjuster collar from the side.

The barbed portion 36 includes two sprung barbs 38 circumferentially separated by fill pieces 40. In use, fill pieces 40 act to locate the barbs 38 in the correct position with respect to the attachment collar 24.

Barbs 38 have a blunted saw tooth shape (see Figs. 11 and 12). Surface 38a tapers radially outwardly, from the lead end of the adjuster portion to be inserted first into the attachment collar, to a flat surface 38b that extends to a radially inward step 38c leading back to the circumference of the fill pieces 40. In this way, when the adjuster collar is inserted into the bore of the attachment collar 24, the barbs 38 are compressed inwardly against the urging of spring arms 42. When the attachment collar is held full on the mounting portion of the adjuster collar, the barbs project beyond the end of the attachment collar and therefore spring outwardly, the step surface 38c of the barbs bearing against the end surface 29 of attachment collar flange 26.

The barbs provide a positive locking feel to the mounting of the attachment collar on the mounting portion of the adjuster collar. Assisting in this is chamfer 44, provided on the mounting portion adjacent the bevelled flange 30. Chamfer 44 is shown in Figs. 10 and 13. The shape of chamfer 44 ensures that the attachment collar engages with the adjuster collar via a click that is discernable to the person assembling the fastener by feel and/or sound (preferably both).

The length of the mounting portion between the chamfer 44 and the sprung barbs 38 has raised ribs 46 projecting from the outer surface. This is shown in Figs. 8 and 9. Ribs 46 determine the frictional interaction between the mounting portion and the internal surface of the attachment collar. It is easier to tune the frictional interaction between the mounting portion and the internal surface of the attachment collar by altering the number, length or height of the ribs than by altering the diameter of the whole of the mounting portion. For this reason, the torque required to turn the adjuster collar within and with respect to the attachment collar can be reliably set at a predetermined level. This torque is set lower than the torque required to turn the adjuster collar about and with respect to the first threaded length 14 of the stud 12. Both torques are set at greater than finger-tight, so that a tool is required to move the adjuster collar with respect to either the stud or the attachment collar.

In the following example, a rear light cluster is attached to a suitable attachment location in a car body, as described above. The fastening device 10 has the adjuster collar 21 and therefore the attachment collar 24 at the zero adjustment limit, i.e. located as far away from the second threaded portion 16 as possible. In this way, when the light cluster is first attached to the car body, the separation between the two is at a maximum. In this example, later adjustment of the fastening device will only serve to reduce this separation.

The car manufacturer sets a tolerance on the separation of the light cluster from the car body. This Is tolerance is determined by many factors including the manufacturing steps performed on the car body during the production process and the final desired separation of the light cluster from the car body. For example, the tolerance might be plus or minus 2 mm.

Once the light cluster is attached to the car body via the fastening device, the separation between the two components can be varied by moving the adjuster collar 21 and therefore the attachment collar 24 along first threaded portion 14 by operation of drive head 22.

One advantage of the adjustment mechanism is that the light cluster and the car body remain firmly attached to the fastening device during the adjustment procedure.

This is because movement of the adjuster collar along the first threaded portion does not cause rotation of the second threaded portion with respect to the light cluster or rotation of the attachment collar with respect to the car body. To assist in keeping the attachment collar fixed with respect to the car body, surface 28 of flange 26 of the attachment collar has an annular rough portion (not shown), typically formed by sharp dimples, that engages with the car body to prevent rotation of the attachment collar with respect to the car body when the nut and washer arrangement forces the rough portion into engagement with the car body.

The light cluster can be attached to the car body using two or more of the fastening devices. Each of these can then be adjusted, allowing the separation between different parts of the light cluster and the adjacent bodywork to be adjusted, and/or allowing the tilt of the light cluster with respect to the bodywork to be adjusted.

The above embodiments are described by way of example. On reading this disclosure, modifications of these embodiments, further embodiments and modifications thereof will become apparent to the skilled person and as such are within the scope of the invention. In particular, the above embodiments have been described with reference to the attachment of a light cluster to a car body, but the invention may be applied to the attachment of other components to car bodies, or indeed to the attachment of components to other components in

other technical fields.

Claims

CLAIMS: 1. A fastening device for fastening a first component to a second

component, having: first attachment means for attachment to the first component; second attachment means for attachment to the second component; and adjustment means, wherein the position of the first attachment means is adjustable relative to the position of the second attachment means via the adjustment means so that, in use with the first component fixedly attached to the first attachment means and the second component fixedly attached to the second attachment means, the separation of the first and second components is adjustable.
2. A fastening device according to claim 1 wherein the first attachment means is moveable on the fastening device by operation of the adjustment means.
3. A fastening device according to claim 1 or claim 2 wherein the first attachment means attaches to the first component by compressing a portion of the first component between opposing surfaces.
4. A fastening device according to claim 3 wherein at least one of the opposing surfaces of the first attachment means includes a rough portion to assist in frictional engagement of the first attachment means with the first component.
5. A fastening device according to any one of claims 1 to 4 wherein the adjustment means is mounted on a first threaded length of the device, its position on the device being alterable by turning of the adjustment means along the threaded portion.

JO
6. A fastening device according to claim 5 wherein the adjustment means includes an adjustment collar engaged on the threaded length of the device, the internal thread of the collar having been tapped by the threaded length of the device.
7. A fastening device according to claim 6 wherein the adjustment collar has a driving portion for engagement with a driving means for positioning the adjustment collar along the threaded length of the device.
8. A fastening device according to claim 6 or claim 7 wherein the collar has a mounting portion on which the first attachment means is mounted, the mounting portion having at least one resilient stop formed at the leading end of the adjustment collar for allowing positive location of one end of the first mounting means on the adjustment collar.
9. A fastening device according to claim 8 wherein the adjustment collar mounting portion includes a flange positioned to locate the other end of the first attachment means on the collar.
10. A fastening device according to claim 9 wherein the mounting portion further includes a chamfered step adjacent the flange.
11. A fastening device according to any one of claims JO 8 to 10 wherein the mounting portion includes at least one projection on its outer surface for frictional engagement with the internal surface of the first attachment means.
12. A fastening device according to claim 11 wherein said at least one projection is a rib.
13. A fastening device according to any one of claims 1 to 12 wherein the second attachment means of the fastening device includes a second threaded length of the device for engagement with the second component by selftapping engagement.
14. A fastening device according to claim 13 wherein, at the end of the shaft distal from the second threaded length, a drive head is provided for driving the attachment of the second attachment means to the second device.
15. A fastening device according to any one of claims 1 to 14 wherein the adjustment means is located at a predetermined distance from the second attachment means, thereby defining a predetermined tolerance for adjustment of the relative positions of the first and second components, in use.
16. A fastening device according to claim 15 wherein the adjustment means is located at or close to its limit JO on the device distal from the second attachment means.
17. A fastened assembly of a first component and a second component, attached via a fastening device to give a predetermined separation between the first and second components, wherein the fastener includes adjustment means for adjusting the position of the first and/or second component on the fastening device, thereby allowing adjustment of the separation between the first and second components independent of the grip between the components and the fastening device.
18. A fastened assembly of a first component and a second component, attached via a fastening device according to any one of claims 1 to 16, the assembly allowing adjustment of the separation between the first and second components independent of the grip between the components and the fastening device.
19. A fastened assembly according to claim 17 or claim 18 wherein the first component is an automobile body and the second component is an automobile component, such as a light cluster.
20. A fastened assembly according to any one of claims 17 to 19 including one or more further fastening devices according to any one of claims 1 to 16, the assembly thereby allowing adjustment of the separation between the first and second components by adjustment of each lO fastening device.
21. A fastened assembly according to claim 20 wherein the fastening devices are arranged relative to the first and second components such that adjustment of the fastening devices allows adjustment of the attitude of the second component with respect to the first component.
22. Use of a fastening device according to any one of claims 1 to 16 to fasten a first component to a second component, the use including the step of adjusting the separation of the first and second components by operation of the adjustment means to alter the position of the first attachment means relative to the position of the second mounting means when the first component is fixedly attached to the first attachment means and the second component is fixedly attached to the second attachment means.
23. A use according to claim 22 wherein the torque required to turn the adjuster collar with respect to the threaded length of the device is greater than the torque required to turn the first attachment means with respect to the adjuster collar.
24. An automobile component fastening device according to any one of claims 1 to 16, wherein the first component is an automobile body.