BELT LENGTH ADJUSTMENT DEVICE

Abstract: A belt length adjustment device comprises a metal plate (2) shaped (14) at one end for securement of the device and having the other end rolled over. An aperture (6) adjacent the rolled over end provides a snubbing edge (10) and the rolled over end is also apertured to provide an end bar (9). A plastics cover provides an arm (20) extending from the vicinity of the rolled over end to the plate and providing a second snubbing edge (22). The snubbing edges engage by resilience of the arm assisted by a spring (30). The loaded belt end extends from between the snubbing edge around the end bar and down the back of the arm to enhance the grip of the snubbing edges. In a variant, the loaded belt end extends forwardly of the arm (64).

Description: BELT LENGTH ADJUSTMENT DEVICE DESCRIPTION The invention relates to a belt length adjustment device, for use for example in vehicle seat belt systems In a knownbelt 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 onan anchored end of the belt causes such sliding movement towards a second metal cylindical 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. An adjustment device of this kind requires the accurate fabrication of a number of metal parts and is consequently both heavy and expensive to produce. Any obstruction to the free movement of the slidable bar, can render the device ineffective. The invention is 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 in which the belt is received between two snubbing elements which are resiliently urged together to releasably retain the belt between them. The belt portion which is under load can be arranged to enhance the gripping force on the belt. The snubbing elements conveniently comprise an edge provided by a metal frame, by which the device can be mounted in a desired location and a plastics cover including an arm with a free end providing the other snubbing element. The arm can be urged to engage its free end with the snubbing edge of the frame by a spring or springs, or by its own resilience. The loaded end of the belt can be arranged to extend around the free end of the arm to assist this pressure and this arrangement has 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 2 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 1800 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 2 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/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 additionally or 22 against the edge 10 under its inherent resilience/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 sufficent 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 within the scope of the invention 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 Aongue, 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 modified, 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: CLAIMS 1. A belt length adjustment device comprising means for connection of the device, and first and second snubbing elements arranged to releasably grip a belt therebetween, characterized in that the snubbing elements (10,22;10,68) are resiliently urged together. 2. A device as claimed in claim 1 wherein the first snubbing element (10) is provided by a rigid frame (2) and the second snubbing element (22;66) is carried by a resiliently urged movable arm (20,64). 3. A device as claimed in claim 2 wherein the rigid frame has a first end portion providing the connection means (4;42) and a second end portion beyond the first snubbing element (10), the second end portion extending laterally of the engagement faces of the snubbing elements (10,22;10,66) and providing a guide bar (9) round which the belt extends from the snubbing elements and generally along the direction of the arm (20,64). 4. A device as claimed in claim 3 wherein the arm (20) extends from the guide bar (9) and the belt extends therefrom along the side of the arm remote from the second snubbing element (22). 5. A device as claimed in claim 3 wherein the arm (64) extends from a position adjacent but spaced from the guide bar (9) and the belt extends from the guide bar through a slot between the arm and the second snubbing element (66). 6. A device as claimed in claim 3, 4 or 5 wherein the rigid frame has secured thereto a hollow shell (11;60) of resilient material, the shell having the arm (20;64) as an integral part thereof extending internally towards the frame. 7. A device as claimed in claim 6 wherein the arm (20,64) is spring-urged by a compression spring acting on the arm adjacent the second snubbing element (22;66). 8. A device as claimed in claim 7 wherein the shell (11;60) provides a mounting for the end of the compression spring remote from the arm (20;64). 9. A device as claimed in any one of claims 2 to 6 wherein the arm (20,64) is inherently resilient and/or is resiliently urged by a spring (30;70). 10. A device as claimed in any one of claims 2 to 9 wherein the arm (20,64) has one or more extension portions (54) manually engageable to release the grip on the belt.

Inventors: ANDERSON, ALEXANDER BARRIE
Applicants: ASE (UK) LIMITED
Application year: 1981
Main classification: A44B11
IPC codes: A44B11