GB2247393A

GB2247393A - Improvements in or relating to a belt deflector

Info

Publication number: GB2247393A
Application number: GB9019156A
Authority: GB
Inventors: Tony Jonsson
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1990-09-03
Filing date: 1990-09-03
Publication date: 1992-03-04
Anticipated expiration: 2010-09-03
Also published as: GB2247393B; GB9019156D0

Abstract

A deflector for a safety-belt 8 in a motor vehicle has an element 4 defining a deflecting surface (5, Fig. 2) about which the belt is deflected. This element is mounted on a support 1 and is resiliently biassed to a first position (as shown). The element is movable to a second position (Fig. 3), against the bias, when a tension is applied to the belt. When the element is in the second position it engages an underlying support surface 2 to transfer force directly from the belt to the underlying support. <IMAGE>

Description

DSSCRIPTION OF INVENTION "Improvements in or relating to a belt deflector?? THE PRESENT INVENTION relates to a belt deflector and more particularly relates to a belt deflector suitable for use with a safety belt.

It is known to utilise a belt deflector to defleet a safety belt for use in a motor vehicle. Typically such a belt deflector comprises a plate or the like, the lower part of which defines an elongate aperture through which the belt passes, the upper part of the plate being provided with a further aperture which receives a bolt to mount the plate in position for pivotting about an axis which is substantially perpendicular to the axis of the deflecting surface defined by the lower edge of the elongate aperture belt.

It is to be appreciated that the tension and stresses present in the belt, particularly under accident circumstances, are transferred to the plate and are thus transferred to the bolt, and consequently the plate must be relatively strong to be capable of withstanding the forces.

The present invention seeks to provide an improved belt deflector.

According to this invention there is provided a deflector for a belt, the deflector having an element defining a deflecting surface, about which the belt is deflected, the element being mounted on a support, and being resiliently biassed to a first position, the said element being movable against the bias when a tension is applied to the belt to a second position, the element, in the second position, engaging the underlying support to transfer force directly from the belt to the underlying support.

In one embodiment said element is pivotally mounted in position.

Preferably the pivotting axis extends perpendicularly to the axis of the part of the deflecting surface engaged by the belt.

Conveniently the deflector element is pivotally mounted on a support plate, the support plate having an upper edge which is inclined to the horizontal, the deflector element being pivotal about a pivot axis located adjacent the upper edge of said inclined edge of the support plate, the arrangement being such that when a force is applied to the belt, a pivotting action takes place moving the deflecting element from an initially horizontal position to an inclined position in which the deflecting element firmly engages the said inclined upper edge of the support plate.

In one embodiment the upper edge of the deflector is rounded so that the safety belt can slide over the upper edge of the deflector.

Preferably the lower surface of the deflector is under-cut to provide a recess, the inclined upper edge of the support plate being received within the recess when the deflecting element has moved against the spring bias.

In alternative embodiments the deflector element comprises a roller.

Preferably when the roller has been moved against said resilient bias, part of the periphery of the roller engages a recessed bed formed on a support element.

Preferably the bed defines a high friction surface.

Conven.ently the high friction surface is formed so that it presents a high friction effect to rotation in one sense but a lesser frictional effect to rotation n the opposite sense.

Preferably the high friction surface is constituted by serrations.

In one embodiment the roller is mounted on a mounting plate, the mounting plate being pivotally mounted on the sport plate.

In another embodiment the roller may move in a d;reclon substantially perpendicular to the axis of the roller.

Preferably the roller is mounted, by means of trunnions, in two elongate guide slots, the roller being biassed to a position such that the trunnions are located at one end of each respective guide slot, the trunnions each being movable against the resilient force to a position further down the said guide slots.

Conveniently the roller is provided with term inal flanges.

Advantageously the roller is of non-uniform cross-section and thus has different diameters at different points along its axis.

This invention also relates to a seat for a motor vehicle having mounted, in the back of the seat, a deflector as described above.

Advantageously the deflector is mounted adjacent one side of the seat, the axis defined by the surface deflecting the belt extending downwardly, with respect to the horizontal, towards that side of the seat.

Preferably the deflector is mounted adjacent one side of the seat, the axis, defined by the surface deflecting the belt, extending forwardly, towards that side of the seat, having respect to a plane defined by the back of the seat.

In order that the invention may be more readily understood, and so that further features thereof may be appree ated, the invention will now be described, by way of example, with reference to the accompanying drawings in which FIGURE 1 is a perspective partially diagrammatic view of one embodiment of the invention in an initial condition, FIGURE 2 is a sectional view taken on the line II-IT of Figure 1, FIGURE 3 if a veiw of the embodiment of Figures 1 and 2 when the belt is under tension, FIGURE 4 is a diagrammatic view of an alternative embodiment of the invention, FIGURE 5 is a side view taken on the line V-V of Figure 4, FIGURE 6 is a diagrammatic sectional view taken on the line VI-VI of Figure 4, FIGURE 7 is a diagrammatic view of a further embodiment of the invention, FIGURE 8 is a view corresponding to Figure 7 when in the operative condition, FIGURE 9 is a sectional side view taken on the line IX-IX of Figure 8, FIGURE 10 is a diagrammatic view of a modified roller for use ifl the embodiment of Figures 4 to 6 or in the embodiment of Figures 7 to 9, FIGURE 11 is a front view of a motor vehicle seat in which a deflector in accordance with the invention is mounted, illustrating the position of the deflector, and FIGURE 12 is a top plan view of the seat of Figure 11, again illustrating the position of the deflector.

Referring initially to Figure 1 a deflector for a safety belt in accordance with the present invention comprises a support element 1 in the form of a vertically upstanding plate. The plate has an inclined upper edge 2, which is inclined to the horizontal. Pivotally connected to the plate, by means of a pivot 3 at a point adjacent the highest part of the inclined upper edge 2, is a guide member 4. The guide member 4 may be made of an appropriate material, such as a plastics material and, as can be seen from Figure 2, the guide member 4 has a rounded upper surface 5 and has an under-cut lower surface defining a recess 6 which is dimensioned to receive the upper edge of the plate 1.A spring 7 is provided adapted to bias the deflector member 4 upwardly to a substantially horizontal position initially illustrated in Figure 1 in which only a very small part of the plate is received within the recess 6. However, the deflector member 4 may move against the bias imparted by the spring 7 to an inclined position as illustrated in Figure 3 in which the deflector member is then inclined with an angle of inclination substantially the same as the angle of inclination of the upper edge 2 of the plate 1. In this position of the deflection member the entire upper edge 2 of the plate 1 is accommodated within the under-cut recess 6. The base of the recess 6 contacts the edge 2 of the plate 1.

A safety belt 8 normally passes over the deflector member 4. The safety belt can normally slide freely over the deflector member, due to the rounded upper surface 5 of the deflector member. However, should a severe force be imparted to the safety belt 8, for example under accident conditions, the deflector member will move downwardly, against the bias of the spring 7, pivotting about the pivot axis 3, so that the upper edge 2 of the plate 1 is received within the under-cut recess 6, with the edge 2 incontact with the base of the recess 6 and thus the force applied to the belt 8 will then be effectively directly applied to the support plate 1. The support plate 1 will be made sufficiently strong to be able to withstand the applied force.

It is to be appreciated that the guide member 4 pivots about an axis which is substantially perpendicular to the axis of the deflecting surface, but the pivot axis is located at a position which is beneath the part of the belt that engages the deflector member 4.

Referring now to Figure 4 in a second embodiment of the invention a support frame 10 is provided consisting of an element which has two opposed upstanding arms 11,12. Each arm has in it a vertically extending elongate slot or aperture 13, the two slots receiving trunnions 14 provided at the ends of a roller 15 which is thus mounted in a manner that it can rotate about the axis of the trunnions 14.

An element of resilient material 16 is located beneath each trunnion 14 within the respective aperture 13. The resilient material serves to bias the trunnions 14 towards the top of each elongate aperture 13 but, if a downward force is applied to the roller 15, the trunnions may move downwardly, thus compressing the resilient material 16, permitting the roller to move downwardly against a bias provided by the resilent material. The roller thus moves perpen dicularly to the axis of the roller, but if an uneven force is apFl ed to the roller one end may move downwardly more than the other end.

The support 10 includes a bed 16 which extends beneath the roller 15, at a position slightly spaced from the roller 15 when the trunnions 14 are at the top of the respective apertures 13. The bed 16, as can be seen more clearly in Figure 6 is a recess, extending parallel with the roller, having a recessed cross-section which corresponds with part of the periphery of the roller, and which is provided with serrations 17 which thus present a high friction effect when the roller is in contact with the serrations.

A safety belt 18 is guided over the roller 15.

It will be appreciated that, under normal circumstances, when the safety belt 18 is moved the roller 15 will rotate. However, when a severe force is applied to the safety belt, the roller 15 will move downwardly, thus moving the trunnions 14 downwardly within their guide slots 13 against the biassing effect provided by the resilient material 16 and then the under-surface of the roller 15 will engage serrations 17. This will provide a high friction effect, particularly after rotation (in the manner illustrated in Figure 6) in the clock-wise direction of the roller 15. A lesser frictional effect will be provided with regard to counter-clockw se rotation.

It is to be appreciated that, in this embodiment also, when a severe force is applied to the safety belt 18 the force will be applied directly to the roller 15 and will thus be applied directly to the bed 16 forming part of the support 10.

Referring now to Figure 7 of the accompanying drawings, a support 20 in the form of a vertical plate is provided, the vertical plate having an inclined upper edge 21 which forms a bed as will be described hereinafter. Towards the upper part of the inclined surface 21 is provided a pivot 22 on which is pivotally supported a mounting plate 23. The mounting plate 23 is spring-biassed to the position illustrated in Figure 7 by means of a spring 24.

The mounting plate 23 has mounting lugs 25 which extend perpendicularly to the plate 23, the lugs supporting, between them, a roller 26. The lugs 25 are so dimensioned that the trunnions 27 of the roller are located substantially above the support plate 20 in the plane defined by the support plate as can be seen from Figure 9.

A safety belt 28 normally passes over the roller 26. When the belt deflector is in the condition illustrated in Figure 7 the roller 26 may rotate freely, thus enabling the belt 28 to move without obstruction.

If a moderate force is applied to the belt 28, a downward force is applied to the roller 26, causing the supporting plate 23 to pivot about the pivot axis 22, against the bias of the spring 24. The pivot axis 22 is located beneath that part of the belt 28 which normally engages the roller 26. Under the action of only a moderate force the plate 23 will not move a sufficient distance for the roller to engage the bed 21 and thus the roller may still rotate. However, when a significant force is applied to the belt and causes the plate 23 to pivot downwardly, the lower part of the roller is brought into engagement with the bed 21 defined by the upper edge of the plate 20. As can be seen from Figure 9 the bed 21 is of recessed form so that it accommodates and engages a peripheral part of the roller 26.

Thus, any significant force applied to the roller 26 by the savei*- belt 28 is transferred directly from the roller 25 to the support plate 21 which is dimensioned so as to be able to withstand the applied force.

Figure 10 illustrates a modified type of roller 30 which can be used instead of the roller 15 of the embodiment of Figure 4 or instead of the roller 26 of the embodiment of Figure 7. It is to be noted that the roller 30 is not a cylindrical roller but instead is a roller having a non-uniform cross-section. Thus the roller 30 is of relatively small cross-section towards its left-hand end, as illustrated, at the point 31, and increases to a maximum dimension towards the other end 32 of the roller but, at the other end of the roller has again a portion 33 of relatively small cross-section. The roller of Figure 10 is provided with end flanges 34,35 which serve to guide and retain the belt 36 on the roller. A cover 38 is provided.

A roller having the configuration of Figure 10 not only guides the safety belt, by means of the terminal flanges, so that the safety belt is retained in engagement with the roller, but by virtue of the non-uniform cross-section of the roller, enables the safety belt to leave the roller at an inclined angle wlthout the safety belt losing contact with a significant part of the outer surface of the roller.

It is envisaged that a safety belt deflector of the type described above may be mounted within the back 40 of a vehicle seat 41, as shown in Figures 11 and 12. The deflector 43 would be located at a position on the seat to be located above one shoulder of a person occupying the seat. Thus the deflector 43 would be mounted in position so that the axis of the portion of the deflector contacted by the belt will, when the belt is in use, be inclined downwardly, towards the adjacent edge of the seat, as indicated by the angle alpha in Figure 11. However, as can be seen from Figure 12, the axis of the deflecting surface will not extend in the plane generally defined by the back 40 of the seat 41, but instead will extend forwardly of that plane by an angle beta as shown in Figure 12. Thus the guiding surface will, in operation of the device, be inclined downwardly and outwardly and will also be inclined forwardly from the plane defined by the back of the seat.

Claims

CLAINS:

1. A deflector for a belt, the deflector having an element defining a deflecting surface, about which the belt is deflected, the element being mounted on a support, and being resiliently biassed to a first position, the said element being movable against the bias when a tension is applied to the belt to a second position, the element, in the second position, engaging the underlying support to transfer force directly from the belt to the underlying support.

2. A deflector according to Claim 1 wherein said element is pivotally mounted in position.

3. A deflector according to Claim 2 wherein the pivotting axis extends perpendicularly to the axis of the part of the deflecting surface engaged by the belt.

14. A deflector according to Claim 2 or 3 wherein the deflector element is pivotally mounted on a support plate, the support plate having an upper edge which is Inzlin to the horizontal, the deflector element being pivotal about a pivot axis located adjacent the upper edge of said inclined edge of the support plate, the arrangement being such that when a force is applied to the belt, a pivotting action takes place moving the deflecting element from an initially horizontal position to an inclined position in which the deflecting element firmly engages the said inclined upper edge of the support plate.

5. A deflector according to any one of Claims 2 to 4 wherein the upper edge of the deflector is rounded so that the safety belt can slide over the upper edge of the deflector.

6. A deflector according to any one of Claims 1 to 5 wherein the lower surface of the deflector is under-cut to provide a recess, the inclined upper edge of the support plate being received within the recess when the deflecting element has moved against the spring bias.

7. A deflector according to any one of Claims 1 to 4 wherein the deflector element comprises a roller.

8. A deflector according to Claim 7 wherein when the roller has been moved against said resilient bias, part of the periphery of the roller engages a recessed bed formed on a support element.

9. A deflector according to Claim 8 wherein the bed defines a high friction surface.

10. A deflector according to Claim 9 wherein the high friction surface is formed so that it presents a high friction effect to rotation in one sense but a lesser frictional effect to rotation in the opposite sense.

11. A deflector according to Claim 10 wherein the high friction surface is constituted by serrations.

12. A deflector according to any one of Claims 7 to 11 wherein the roller is mounted on a mounting plate, the mounting plate being pivotally mounted on the support plate.

13. A deflector according to any one of Claims 7 to 11 wherein the roller may move in a direction substantially perpendicular to the axis of the roller.

114. A deflector according to Claim 13 wherein the roller is mounted, by means of trunnions, in two elongate guide slots, the roller being biassed to a position such that the trunnions are located at one end of each respective guide slot, the trunnions each being movable against the resilient force to a position further down the said guide slots.

15. A deflector according to any one of Claims 7 to 14 wherein the roller is provided with terminal flanges.

16. A deflector according to any one of Claims 7 to 15 wherein the roller is of non-uniform cross-section and thus has different diameters at different points along its axis.

17. A seat for a motor vehicle having mounted, in the back of the seat, a deflector according to any one of Claims 1 to 16.

18. A seat according to Claim 17 wherein the deflector is mounted adjacent one side of the seat, the axis defined by the surface deflecting the belt extending downwardly, with respect to the horizontal, towards that side of the seat.

19. A seat according to Claim 17 or 18 wherein the deflector is mounted adjacent one side of the seat, the axis, defined by the surface deflecting the belt, extending forwardly, towards that side of the seat, having respect to a plane defined by the back of the seat.

20. A deflector substantially as herein described with reference to and as shown in Figures 1 to 3 of the accompanying drawings.

21. A deflector substantially as herein described with reference to and as shown 9n Figures 4 to 6 of the accompanying drawings.

22. A deflector substantially as herein described with reference to and as shown in Figures 7 to 9 of the accompanying drawings.

23. A deflector substantially as herein before with reference to and as shown in Figures 4 to 6, or 7 to 9 of the accompanying as modified by Figure 10 of the accompanying drawings.

24. A seat for a motor vehicle substantially as herein described with reference to and as shown in Figures 11 and 12 of the accompanying drawings.

25. Any novel feature or combination of features disclosed herein.