EP0040062B1

EP0040062B1 - Belt length adjustment device

Info

Publication number: EP0040062B1
Application number: EP19810302047
Authority: EP
Inventors: Alexander Barrie Anderson
Original assignee: Ase UK Ltd
Current assignee: Ase UK Ltd
Priority date: 1980-05-09
Filing date: 1981-05-08
Publication date: 1984-09-05
Also published as: EP0040062A1; DE3165828D1

Description

The invention relates to a belt length adjustment device, for use for example in vehicle seat belt systems.
In a known belt length adjustment device, the belt is trained around a metal cylindrical bar with a knurled surface, carried at its ends for non-rotational sliding movement at right angles to its length in the side walls of a U-shaped metal frame. A pull on an anchored end of the belt causes such sliding movement towards a second metal cylindrical bar parallel to the first and mounted for rotation about a fixed axis. The belt is thereby trapped between the bars, but can be released by a pull on its free end, which slides the knurled bar away from the fixed bar to allow movement of the belt through the device.
A tongue plate device for use in a seat belt system known from US Patent 4 167 054 includes an adjustable webbing locking device comprising a locking plate which is slidably movable relative to a tongue under a spring bias to cause a locking portion of the locking plate to lock the webbing in an opening of the tongue plate.
Such adjustment devices require the accurate fabrication of a number of parts and are consequently expensive to produce. Any obstruction to the free movement of the slidable locking member, can render the device ineffective. The invention is therefore concerned with the provision of a belt length adjustment device which can be of very simple construction whilst providing easy and reliable operation.
The invention accordingly provides a belt length adjustment device comprising a first snubbing element on a rigid frame and a second snubbing element on a member movable relative to the frame, the member being biassed from a position in which the second snubbing element is spaced from the first snubbing element to allow movement of the belt therebetween towards a position in which the belt is snubbed between the two snubbing elements, characterised in that the member is a swingable arm having the second snubbing element thereon, and in that a portion of the belt spaced from the snubbed portion acts on the arm to increase the snubbing pressure on the belt when the belt is loaded.
The snubbing elements conveniently comprise an edge provided by the frame which is preferably metal, by which the device can be mounted in a desired location and a plastics cover providing the swingable arm, the free end of the arm providing the other snubbing element. The arm can be urged to engage its snubbing element with the snubbing edge of the frame by a spring or springs, or by its own resilience.
The arrangement whereby the loaded end of the belt increases the snubbing pressure affords the advantage that a snubbing action will still occur even if the arm should be destroyed under extreme loading conditions as might possibly occur during an accident when the device is employed in a vehicle seat belt system.
The invention is further described below, by way of example, with reference to the accompanying drawing, in which:

Figure 1 is a sectional side view of a belt length adjustment device embodying the invention, comprising a frame, a cover and a spring;
Figure 2 is a perspective exploded view of the frame and cover of the device of Figure 1;
Figure 3 is a perspective view of a modification of the frame;
Figure 4 is a perspective view of a modified form of the cover; and
Figure 5 is a view, resembling that of Figure 1, of an adjustment device embodying the invention with a second modified form of the cover.

In the following, directional expressions such as "left" and "right" and "upwardly" and "downwardly" refer to the belt length adjustment device 1 as shown in Figure 1; the device however can be used in other orientations.
The device 1 of Figures 1 and 2 comprises a metal frame 2 fixedly secured to a cover 11 which can be moulded in plastics material.
The frame consists of a metal plate, which is rectangular in shape, except that the sides taper inwardly to the right hand end, at which a transverse aperture 4 is provided for securement of the device, for example to a suitable vehicle anchorage when the device is incorporated in a seat belt system. At the other end, the plate is bent upwardly and over on itself through 180° to form a semicylindrical portion.
The plate is formed with a transverse aperture 6 in the flat portion immediately adjacent the curved end, and a further transverse aperture 8 in the curved end portion itself. The aperture 6 has a straight edge 10 adjacent the curved end portion which constitutes a snubbing edge.
The cover 11 has the form of a shell which extends generally parallel to the frame 2 from its curved end portion over about the half the length of the flat portion and then tapers downwardly.
The cover 11 has a main body portion engaging the frame 2 between the apertures 4 and 6 and between the aperture 4 and the right hand end. This main body portion overlaps and embraces the outer edges of the frame 2 and also the internal edge of the aperture 4 around an aperture 14 registering therewith. The aperture 14 opens upwardly in smooth convex curves, so that a belt or other securement means can be readily inserted and received therethrough without being exposed to wear through engagement with the metal of the frame.
To the left, the cover 11 has an aperture 16 approximately registering with the frame aperture 6, and engages over the transverse bar 9 formed at this end of the frame by the aperture 8. From the edge of the aperture 16 adjacent the free edge of this bar 9, an arm portion 20 of the cover extends downwardly, the free end of the arm having a transverse edge 22 in facing relation with the snubbing edge 10 of the frame. Just above the upper surface of the frame, the arm portion 20 is formed with an integral extension portion 24 extending to the right, in which is formed a transverse slot 26. A pin 28 extends in the same direction centrally from the extension portion 24 and is received in the end of a compression spring 30 which extends into a pocket formed between the cover body portion and the frame. Depending on the clamping force required, two pins and compression springs or a leaf spring can be employed in place of the spring 30, or the arm 20 can be arranged to urge the edge 22 against the edge 10 under its inherent resilience additionally or alone.
The belt 32 with which the device 1 is used has a free or unloaded portion 34 extending from the left of the device to the snubbing edge 10. Although shown in Figure 1 spaced from the belt, the edge 22 of the arm 20 is urged by the spring 30 to clamp the belt firmly between the edges 10 and 22. From the edges 10 and 22 the loaded portion 36 of the belt 32 extends upwardly over the bar 9 and downwardly adjacent the arm 20 and the to the left towards the load.
It will be seen that the position of the load relative to the device 1 is such that the tension in the loaded portion of the belt acts on the arm portion 20 to add to the snubbing pressure applied by the spring 30.
It will be noted that the device 1 would continue to operate even if the arm 20 were to be broken off or otherwise destroyed because the belt 32 would be gripped between the edge 10 and the loaded belt portion 36.
To tighten the belt 32 against the load, it is sufficient to pull the belt portion 34 to the left. To loosen the belt, portion 36 is pulled downwardly or to the right, or the device 1 is tilted clockwise, so that the belt portion 36 acts on the right hand edge of the slot 26 to withdraw the arm 20 away from the snubbing edge 10.
The device 1 can be modified in various ways for example to constitute one part of the releasable two part buckle. Thus as shown in Figure 3, the securement end of a frame 40 corresponding in other respects to the frame 2 is shaped as a tongue, with a rounded nose and latching edges 42, for reception in the socket part of a buckle provided with a latch member for releasably engaging the edges 42.
The socket part can correspond for example to such parts as are disclosed in GB Application 7927754 (Publication 2027790). The cover (not shown) to be secured to the frame 40 can correspond to the cover 11, with an alteration to expose an adequate length of the tongue for reception in the socket part. Moreover, as shown in Figure 4, a modified form of cover 50 is provided with side apertures 52 through which extend the ends of an extension portion 54 of the arm 20 which corresponds to the extension portion 24 except for its greater width. This form of cover permits direct manual movement of the arm 20 to release the belt by operation of the projecting ends of the portion 54. The cover 50 is shaped for use with the frame 2 but can readily be modified for use with the frame 40.
The device 60 of Figure 5 has a frame which corresponds to the frame 2 and which bears the same reference numerals as this frame; instead, the frame 40 of Figure 3 could be used in the device 60. The cover 62 secured to this frame differs from the covers 11 and 50 essentially in that an arm 64, provided at its free end with an extension position forming a snubbing edge 66 for co-operation with the snubbing edge 10 of the frame 2, depends not from the portion of the cover engaging the bar 9, but from the central portion of the cover engaging the frame between the apertures 4 and 6, which is hollow.
The belt 32 has as before an unloaded portion 34, adjoining a portion shown in Figure 5 as being held between the snubbing edges 10 and 66, from whence the loaded belt portion 36 extends upwardly through the frame aperture 8 and then over the part of the cover 62 around the bar 9. From this position, the belt portion 36 extends downwardly through a transverse slot 68 formed in the extension portion and towards the load. A compression spring 70 is received on opposed pins 72, 74 projecting respectively from the arm 64 and the wall of the hollow cover portion facing the arm.
As with the devices previously described, the snubbing edge 66 is urged towards the edge 10 by a spring, the spring 70, and also by the tension in the belt portion 36. Adjustment of the belt can be carried out in the manner also previously described. As compared with the earlier described devices, that of Figure 5 provides a better degree of concealment of, and protection for, the spring.
The cover 60 can be modifed, as before, so that the arm 64 is biassed by its own resilience and/or by different spring arrangements. Moreover, the extension portion at the lower end of the arm 64 can be extended laterally for manual release operation as with the cover 50 of Figure 4.

Claims

1. A belt length adjustment device comprising a first snubbing element (10) on a rigid frame (2) and a second snubbing element (22; 66) on a member (20; 64) movable relative to the frame, the member being biassed from a position in which the second snubbing element is spaced from the first snubbing element to allow movement of the belt (32) therebetween towards a position in which the belt is snubbed between the two snubbing elements, characterised in that the member is a swingable arm having the second snubbing element thereon, and in that a portion of the belt spaced from the snubbed portion acts on the arm to increase the snubbing pressure on the belt when the belt is loaded.

2. A device as claimed in claim 1 wherein the frame has a guide portion (9) and the belt (32) extends from between the snubbing elements around the guide portion to the position at which the belt acts on the arm (20; 64).

3. A device as claimed in claim 2 wherein the arm (20) is contiguous with and extends from the guide portion (9) and the belt extends therefrom along the arm.

4. A device as claimed in claim 2 wherein the arm (64) extends from a position adjacent but spaced from the guide portion and the belt extends from the guide portion through a slot (68) in the arm adjacent the second snubbing element (66).

5. A device as claimed in claim 2, 3 or 4 wherein the frame (2) comprises a metal plate, the plate having an aperture (6) therein of which one edge constitutes the first snubbing element and an overturned end portion constituting the guide portion (9).

6. A device as claimed in claim 5 wherein the arm (20; 64) is an integral part of a hollow shell (11; 60) of plastics material secured to the frame (2), the arm extending internally of the shell.

7. A device as claimed in claim 6 wherein the plastics shell (11; 60) covers the guide portion (9) of the metal frame (2).

8. A device as claimed in any preceding claim wherein the arm (20, 64) is biassed by a compression spring (30; 70) acting on the arm adjacent the second snubbing element (22; 66).

9. A device as claimed in any preceding claim wherein the arm (20, 64) is biassed by inherent resilience thereof.

10. A device as claimed in any preceding claim wherein the arm (20, 64) has one or more extension portions (54) manually engageable to release the grip on the belt.