GB2449645A

GB2449645A - Seat belt buckle with biasing means

Info

Publication number: GB2449645A
Application number: GB0710187A
Authority: GB
Inventors: Simon Mitchell; James Gooch
Original assignee: Nissan Motor Manufacturing UK Ltd
Current assignee: Nissan Motor Manufacturing UK Ltd
Priority date: 2007-05-29
Filing date: 2007-05-29
Publication date: 2008-12-03
Anticipated expiration: 2027-05-29
Also published as: GB0710187D0; GB2449645B

Abstract

A seat belt buckle assembly is provided. The assembly comprises a seat belt buckle 20, webbing 30 for attaching the seat belt buckle to an anchor point 40 and biasing means 50 configured to ensure that the buckle returns to a predetermined position whenever the buckle is not in use. The biasing means extend substantially along the full length of the webbing. The biasing means may be an elastic strip, said strip passing through loops at the ends of the webbing or through apertures provided by the buckle and anchor point. The elastic strip may be secured to itself so as to form a closed loop. The biasing means allows the buckle to be withdrawn to a storage position when the adjacent seat is folded, thus ensuring that the buckle does not damage the bolsters of the seat.

Description

IMPROVEMENTS IN OR RELATING TO SEAT BELT BUCKLES

The present invention relates to seat belt buckle assemblies and, more particularly, to seat belt buckle assemblies that are suitable for use in vehicle seats that are configured to fold flat.

It is known within the automotive industry to provide a vehicle having seats within one or more rear rows that are configured to fold away in order to maximise the cargo space.

Indeed, for some vehicle types, it is expected that at least a rear row of seats will remain folded away for the majority of the working life of the vehicle. These seats are typically referred to as "occasional seats" as the vehicle user typically makes only occasional use of the facility provided by these seats. It is also known to provide a front row seat that can be folded flat in order to provide a table.

Vehicle seats typically consist of a seat pad or base and a seat back. The seat back is typically pivotable relative to the seat pad in order to allow the passenger to recline the seat to provide a more relaxed seating position. Furthermore, when a seat is configured to be capable of being folded away, it is known for the seat back to pivot forward relative to the seat pad to the extent that the seat back is substantially horizontal. In so-called "tip and tumble" seating arrangements, the seat base and seat back then pivot together so that the seat base and back extend substantially vertically. It is also known to provide a seat in which the seat pad is configured to pivot up to be substantially vertical when the seat is not in use. These configurations can dramatically increase the usable cargo area in a vehicle.

In order to provide a balance between passenger comfort and safety, it is common within the automotive industry to provide a seat back and a seat pad each of which consist of three sections: a central pad or cushion and two bolsters that extend away from the central pad. The central pad is in direct contact with the body of the user in normal use whilst the two bolsters support the user when the vehicle is turning. As a result of their shape, the bolsters provide an improvement to the comfort of the passenger experience and help to contain the passenger and provide some level of protection against unexpected lateral movement.

It is a legal requirement, at least within Europe, that all seating positions are provided with a restraint for the occupant. In current vehicles these restraints typically take the form of a three point seat belt which is fastened, in use, using a seat belt buckle. The seat belt buckle is typically located in the region of the line about which the seat back pivots relative to the seat base. The buckle is typically attached to the seat, although it may alternatively be attached directly to the vehicle floor.

When an occasional seat comprising the seat pad and bolsters is provided with a seat belt system, it can be difficult to stow the seat belt buckle satisfactorily. The seat belt buckle can be sandwiched between the bolster provided on the seat back and the bolster provided on the seat base. Whilst this is suboptimal for standard seats, it is more problematic for occasional seating because the compression of the bolsters by the seat belt buckle can result in witness marks on the bolsters.

It is against this background that the present invention has been made.

According to the present invention there is provided a seat belt buckle assembly comprising: a seat belt buckle, webbing for attaching the seat belt buckle to an anchor point and biasing means configured to ensure that the buckle returns to a predetermined position whenever the buckle is not in use, wherein the biasing means extend substantially along the full length of the webbing. Because the biasing means is configured to extend substantially along the full length of the webbing, the strength of the elastic does not need to be as great as if the biasing means were only configured to extend along a small part of the webbing.

The biasing means may be an elastic strip which may be elongate and may be configured to interface only with the components of the assembly. The elastic strip may interface with the assembly by passing through one or more parts of the assembly and being attached solely to itself. The biasing means may be substantially parallel to the webbing. The webbing may comprise two fixing loops, one at each end and wherein the biasing means interfaces with the webbing by passing through each of the loops in the webbing. Alternatively, the biasing means may interface with the anchor and the seat belt buckle.

The assembly may further comprise fixing means, which may be a hog ring or crimp, for securing elastic strip to form a closed loop.

The seat buckle assembly may be incorporated into a seat assembly comprising: a seat pad having a seat cushion and at least one bolster, a seat back having a back cushion and at least one bolster, wherein the predetermined position to which the buckle returns abuts the seat cushion.

The present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a top view of a seat belt buckle assembly according to a first example of the present invention; Figure 2 shows a side view of a seat belt buckle assembly according to the example of the present invention shown in Figure 1; Figure 3 shows an underside view of a seat belt buckle assembly according to a second example of the present invention; Figure 4 shows two seat belt buckle assemblies according to the present invention in situ within a seat assembly; and Figure 5 shows a part cut-away view of a seat assembly incorporating the seat belt buckle assembly shown in Figures 1 to 3.

Figures 1 and 3 show views of seat belt buckle assemblies 10 according to two different examples of the present invention. Throughout the following description, like reference numerals will be used with reference to the examples shown in Figures 1 and 3 for those parts that are common between the two examples. The assembly 10 includes a seat belt buckle 20, webbing 30 and an anchor 40.

The buckle 20 provides, at a first end 21, a fixing for a seat belt. At a second end 22, opposite the first end 21, the buckle 20 is provided with a U-shaped inclusion 23 and a cross bar 24. A button (not shown), or other suitable release means, is provided to enable a user to release the seat belt from the buckle 20. In the example shown in Figure 1 the U-shaped inclusion 23 extends through the full depth of the buckle 20.

However, in further examples of the present invention not shown in the accompanying figures, the inclusion 23 could consist of a mere indentation that does not extend through the full width of the buckle.

The anchor 40 is used to attach the buckle 20, via the webbing 30 to either the vehicle seat or the vehicle floor. The anchor 40 has a screw-threaded bolt 41 and a collar 42.

The screw-thread on the bolt 41 enables the bolt 41 to be screwed into a suitable receiving portion (not Shown) on either the vehicle seat or the vehicle floor. The collar 42 is provided with two apertures 43, 44. The first aperture consists of a substantially circular opening 43 that interfaces closely with the bolt 41. The second aperture 44 is elongate and interfaces with the webbing 30. The collar 42 is held in place on the bolt 41 by a washer 45. The aperture 44 is surrounded by a spacer 46 that permits a small angular deviation in the position of the webbing 30 relative to the anchor 40. The spacer 46 also prevents the interface between the webbing 30 and the anchor 40 from squeaking.

The webbing 30 is used to attach the buckle 20 to the anchor 40. The webbing 30 is formed from a single piece of webbing. For convenience, the webbing 30 may be thought of as consisting of a central portion 31 that is substantially rectilinear and two tapered end portions 32, 33. The webbing 30 is formed into a loop, passing through the inclusion 23 in the buckle 20 and the aperture 44 in the anchor 40. The two ends of the webbing 30 are then brought together in the central portion 31 and secured using stitching 34. The tapered end portions are formed from webbing of the same width as the central portion 31 but the edges are folded inwards to provide a sufficient reduction in width for the end portions to pass through the inclusion 23 and the aperture 44.

The assembly 10 is provided with an elongate elastic strip 50, best viewed in Figure 2, for biasing the assembly as a whole. The strip 50 is attached to the assembly 10 in both of the end regions of the webbing 30. In the example shown the strip 50 passes through the loops created by the tapered end portions 32, 33 of the webbing 30 in the vicinity of the inclusion 23 in the buckle 20 and the aperture 44 in the anchor 40. The strip 50 is then formed into a closed loop by attaching the two ends of the strip 50 together. As a result of the fact that the natural extent of the strip in the lengthwise direction of the webbing is less than the length of the webbing 30, the strip 50 biases the webbing to curve so that the elastic of the strip 50 can return to, or at least approach, its natural length.

As shown in Figure 2, the strip 50 extends substantially along the entire length of the webbing 30. As a result of this configuration, the elastic properties of the strip 50 are distributed across substantially the full length of the webbing 30. The modulus of elasticity of the strip 50 is therefore less than that which would be required if the strip 50 extended only across a part of the webbing 30. The parts of the strip 50 that loop through the tapered portions 32, 33 of the webbing naturally move towards the central portion of the loops formed as the tapered portions of the webbing 30 interlace with the inclusion 23 in the buckle 20 and the aperture 44 in the anchor 40. As a result, the strip 50 tends to extend across slightly less than the full length of the webbing, although this is contemplated to fall within the expression "substantially across the full length of the webbing".

The strip 50 is fabricated from an elastic material with a circular cross sectional area.

This shape is chosen to maximise the elasticity whilst minimising the diameter of the strip. The diameter of the strip 50 is considerably smaller than the width of the webbing 30. As a result of the difference in width, the strip 50 is substantially obscured from view by the webbing 30 so that the occupant's attention is not drawn to the presence of the strip 50 in normal use. In order to reduce further the impact of the strip 50 on the seat occupant, the strip 50 is typically fabricated from a dark coloured elastic material that substantially matches the colour of the webbing 30.

In an alternative example of the present invention not illustrated in the accompanying drawings, the strip 50 is attached directly to the anchor 40 and the buckle 20 by passing the strip 50 through the aperture 44 in the anchor and the inclusion 23 in the buckle.

The two ends of the elastic strip 50 are fixed together using a hog ring or crimp (not shown). A crimp is preferred because it does not increase the overall envelope of the strip 50. The crimp or hog ring can be arranged so that it lies either within the loop of webbing 30 that interfaces with the inclusion in the buckle 20 or within the loop of webbing that interfaces with the aperture 44 of the anchor 40. The fixing is therefore not visible to the seat occupant.

In the simplest example, shown in Figure 2, the two ends of the strip 50 are attached together so that the strip 50 forms a single loop passing through the inclusion 23 of the buckle 20 and the aperture 44 of the anchor. In this example the strip 50 lies substantially parallel to the edges of the central portion 31 of the webbing 30.

However, it is also possible, as shown in Figure 3 for the strip 50 to be attached to itself in order to form a figure of eight. This configuration may be achieved by a single attachment point fixing together the two ends and a point substantially in the middle of the strip 50. Alternatively, the strip 50 may be formed into a loop using a hog ring that is then secreted within one of the tapered ends 32, 33 of the webbing. In this case, the figure of eight is then formed by a separate fixing joining together the two halves of the strip 50 to form a figure of eight. In this configuration, the strip 50 is concealed beneath the webbing 30 in normal use.

In alternative examples of the present invention other fixing means could be used provided it could be fitted into at least one of the loops in the webbing 30 in order to conceal it from the occupant in normal use. The two ends of the elastic strip 50 could even be tied together, although it may be difficult to conceal the knot.

Because the elastic strip 50 is attached to the assembly 10 by fixing the two ends of the strip 50 together, it is not necessary for the strip 50 to be attached directly to the webbing 30. This ensures that the installation of the strip 50 cannot negatively impact on the functionality of the webbing 30. The integrity of the webbing 30 is vital to the effective functioning of the seat belt assembly as a whole and therefore it is of paramount importance that the strip 50 complements the originally intended functionality of the webbing 30.

The strip 50 can be retrofitted to almost any buckle because the majority of the buckles on the market currently provide at least one way in which a strip could be attached thereto.

Furthermore, the strip 50 shown in Figures 2 and 3 interfaces only with other parts of the assembly 10. Although the assembly 10 is shown in the context of a vehicle seat in Figures 4 and 5 it does not require any other features of the vehicle seat to function. As a result the assembly 10 is fully compatible with any type of vehicle seat without modification to the vehicle seat.

Figures 4 and 5 show a cross section and part perspective view respectively of the assembly 10 in situ on a vehicle seat 60. The vehicle seat 60 comprises a seat pad 61 and a seat back 62. The seat pad 61 comprises a seat cushion 63 and two bolsters 64 and 65. The seat back 62 comprises a back cushion 66 and two bolsters 67, 68. The anchor 40 attaches the assembly 10 to the vehicle floor and the webbing 30 extends up the side of the seat pad 61, adjacent one of the bolsters 64, 65.

As is most clearly apparent from Figure 4, when the seat 60 is folded away, there is a small gap 69 between the seat cushion 63 and the back cushion 66. However, there is very little or no space between the pairs of bolsters 64, 67 and 65, 68. The strip 50 of the seat buckle assembly 10 biases the buckle 20 so that it always falls into the gap 69 between the seat cushion 63 and the back cushion 66. Therefore, the buckle 20 is prevented from lying between the bolsters 64, 67 and damaging the shape of the bolsters if the seat remains in the stowed position for a protracted period of time.

Figure 5 shows the seat 60 in its in-use position. The buckle 20, webbing 30 and anchor are shown, but the strip 50 is not shown for clarity. The buckle 20 is biased to lie on the seat cushion 63. The biasing force provided by the strip 50 is sufficient to ensure that, even if the buckle 20 is pulled out of place so that the upper face of the buckle 20 is brought into contact with the bolster 64, the biasing force will be sufficient to return the buckle to the position shown in Figure 5 when the buckle 20 is released. The biasing force is, however, limited so that the occupant will have no difficulty in lifting the buckle 20 from the position shown in Figure 5 in order to use the buckle 20 to fasten a seat belt.

The elasticity of the strip 50 is sufficiently low, in comparison with the resilience of the webbing 30, that the webbing 30 does not form a concertina under the elastic force provided by the strip 50. However, the elasticity of the strip 50 is selected so that it is sufficient to ensure that, even if the buckle 20 is forced out of its natural position so that the webbing 30 is temporarily forced beyond its in-use position such that the buckle 20 abuts a cushion or bolster of an adjacent seat or central console portion 70, the biasing force provided by the strip 50 will be sufficient to cause the webbing to return to the at-rest position shown in Figure 5 when the buckle 20 is released.

The surface shown in Figure 1 will interface, in use, with the seat cushion 63. As the strip 50 does not contribute to the footprint of the belt assembly 10, it cannot leave witness marks on the seat cushion 63. Conversely, in the second example of the present invention, shown in Figure 3, a considerable proportion of the strip 50 is in contact with the seat cushion 63. However, provided the gap 69 is sufficient to ensure that there is no downward pressure on the buckle 20 when the seat is in the stowed position, the will be no marking of the seat cushion 63.

Claims

1. A seat belt buckle assembly comprising: a seat belt buckle, webbing for attaching the seat belt buckle to an anchor point and biasing means configured to ensure that the buckle returns to a predetermined position whenever the buckle is not in use, wherein the biasing means extend substantially along the full length of the webbing.

2. The assembly according to claim 1, wherein the biasing means is an elastic strip.

3. The assembly according to claim 1 or claim 2, wherein the biasing means interface only with the components of the assembly.

4. The assembly according to claim 2 or claim 3, wherein the elastic strip interfaces with the assembly by passing through one or more parts of the assembly and being attached solely to itself.

5. The assembly according to any preceding claim, wherein the biasing means are substantially parallel to the webbing.

6. The assembly according to any preceding claim, wherein the webbing comprises two fixing loops, one at each end and wherein the biasing means interfaces with the webbing by passing through each of the loops in the webbing.

7. The assembly according to any one of claims 1 to 5, wherein the biasing means interface with the anchor and the seat belt buckle.

8. The assembly according to any one of claims 2 to 7, wherein the assembly further comprises fixing means for securing elastic strip to form a closed loop.

9. The assembly according to claim 8, wherein the fixing means is a crimp.

10. A seat assembly comprising: a seat pad having a seat cushion and at least one bolster, a seat back having a back cushion and at least one bolster, and a seat belt buckle assembly according to any one of the preceding claims, wherein the predetermined position to which the buckle returns abuts the seat cushion.

11. A seat buckle assembly as heretofore described with reference to Figures 1, 2 or 3 of the accompanying drawings.