A SEAT BELT FITTING

Abstract: A seat belt fitting is provided which comprises a guide element (11) mounted on a carriage (8) that is movable along a rail (1) or the like. The rail (1) may be mounted on the "B" post of an automobile so that the position of the guide element (11) can be adjusted up-and-down relative to the shoulder of a person sitting in the automobile. The carriage (8) can be selectively retained in a plurality of different positions along the rail (1). In the invention a spring strip (15) has one end connected to the carriage (8), and the other end wound into a spiral (18). The spiral portion of the spring is retained in a predetermined position and the spring imparts a bias to the carriage (8) tending to cancel out a bias supplied to the carrier by the seat belt (13).

Description: THE PRESENT INVENTION relates to a seat belt fitting and more particularly the present invention relates to an adjustable fitting which can be utilised to adjust the height at which a diagonal portion of a seat belt fitted to the front seat of a motor vehicle is effectively connected to the "B" post and/or which can be utilised with a seat belt fitted in the rear of a motor vehicle. At the present time it is common to utilise a front seat belt consisting of a lap-and-diagonal belt. Such a belt has one end thereof anchored in position adjacent the base of the "B" post of the door of the vehicle, and the belt also passes slidably through a guide plate located adjacent the top of the "B" post, the other end of the belt being connected to a retractor reel which is again located adjacent the base of the "B" post. A tongue or the like is mounted on the belt, and when the belt is used the tongue is drawn across the lap of the person utilising the seat belt, and the tongue is then inserted in a buckle which is rigidly connected to the chassis of the motor vehicle on the side of the seat which is remote from the "B" post. When this sequence of events is performed, part of the seat belt extends across the lap of the person wearing the seat belt, and another part extends, from the tongue diagonally across the chest of the wearer of the seat belt, to the plate this is located adjacent the top of the "B" post. It is also becoming common to use a correspondingly designed belt in the rear seat of a motor vehicle. Such scat belts are commonly provided in motor cars, and it has been proposed that the position of the upper guide plate should be adjustable, thus enabling the precise positioning of the diagonal portion of the belt to be adjusted, having regard to the height or size of the person wearing the seat belt. Thus previously it has been proposed to mount a short length of track, or the like, on the "B" post in the case of a front seat belt, and to have the upper plate mounted on a carriage that can slide along the track and be locked in a selected one of a plurality of possible positions. One disadvantage with such an arrangement is that when the guide plate is moved downwardly, the seat helt retractor reel will draw in a portion of the seat belt, thus effectively assisting the downward movement of the plate and the associated carriage. However, when the guide plate is moved upwardly, the upward movement is effected against the downward bias provided by the retractor reel, and thus a considerable force must be applied to the slidable carriage to move it upwardly against this bias. As will be appreciated the slidable carriage is located just above the shoulder of a person sitting in the seat, who is to wear the seat belt, and it is only when the person is in this position that the position of the carriage will be adjusted. It is very awkward for a person to grasp manually an item that is located immediately adjacent their shoulder and then move that item upwardly against a downward bias. Thus people tend not to utilise the adjustable provision that has been made. According to this invention there is provided a seat belt arrangement comprising a guide element through which part of the seat belt passes, the guide element being mounted on a carriage that is movable along a rail or the like, the carriage being provided with means to selectively retain or lock the carriage in a plurality of positions along said rail, means being provided to impart a bias to the carriage against any bias applied thereto by the seat belt, said bias imparting means comprising a spring strip, said spring strip having an initial linear portion which merges into a spirally wound portion so that the linear portion is tangential to the outermost turn of the spirally wound portion, the opposed ends of the spring strip being respectively connected to the carriage and retained at a substantially predetermined position. The pre-characterising portion of claim 1 corresponds to FR-A-2564792 published on 29.11.85. Preferably the spirally wound portion is retained within a cavity. In one embodiment of the cavity is defined by a housing which is retained at a substantially predetermined position. Preferably said carriage is provided with a hook-like element which engages an aperture formed in an end of the spring strip. Conveniently the spring strip is formed of steel, and is of substantially rectangular cross section. The strip may be flat or slightly arcuate in cross section. Advantageously said rail comprises a channel along which the carriage may slide, the channel being provided with a plurality of apertures therein and the carriage being provided with releasable means to engage said apertures, to constitute the means to retain or lock the carriage in said positions. In order that the present invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described with reference to the accompanying drawings in which; FIGURE 1 is a perspective view, with parts shown in phantom, of one embodiment of the invention, and FIGURE 2 is a perspective view of the spring that forms an important part of the embodiment of Figure 1. Referring to the accompanying drawings, a channel 1 is provided which is intended to be mounted on the "B" post of a motor vehicle. The channel has a flat base portion 2, and two upstanding side walls 3,4 which terminate with inwardly directed flanges 5, 6. A plurality of apertures are formed in the channel, each aperture being formed partly in a side wall 3 or 4 and partly in the adjacent flange 5 or 6. The apertures 7 are shown as being of generally square configuration and are evenly spaced, the apertures 7 in the side wall 3 of the flange 5 being coaligned with corresponding apertures in the side wall 4 of the flange 6. A carriage 8 is provided which can move slidably along the channel. The carriage 8 is provided with means (not shown) for releasably engaging the apertures 7 to lock the carriage in a selected one of a plurality of possible positions. The engagement means can be dis-engaged by pressing inwardly two spring biassed buttons 9, and when these buttons 9 have been pressed inwardly the carriage can move upwardly and downwardly, the carriage being re-locked in position by releasing the buttons. Securely bolted to the carriage by means of bolt 10 is a triangular plate 11 having a horizontal oval slot 12 located adjacent the lowermost edge thereof. Part of a seat belt 13 slidably passes through the slot 12. As will be appreciated the seat belt 13 forms part of a conventional lap-and-diagonal seat belt arrangement, but the positioning of the upper end of the diagonal portion of the seat belt may be adjusted by moving the carriage 8 up or down the channel 1. The uppermost end of the carriage 8 is provided with a hook-like projection 14, to which is connected one end of a spring steel strip 15 which is of substantially flat rectangular cross section. The said one end of the spring strip 15 is provided with an aperture 16 through which the hook-like portion is engaged. The spring strip has an initial linear portion 17, which merges into a spirally wound portion 18. The linear portion 17 is thus tangential to the outermost turn of the spirally wound portion 18. At all time the long sides of the flat cross section of the strip are substantially parallel with the axis of the spiral. The spiral portion 18 of the spring is retained on a spool 19 which is accommodated within a housing 20, which is retained at a substantially predetermined position. Alternatively the spiral portion 18 may just be retained within an appropriate cavity within the housing, and need not be mounted on any axle, spool or the like. It has been found that the spring bias provided by a spirally wound spring strip when the strip is extended by applying a tangential force to one end of the spring is substantially linear over a substantial range of extension of the spring strip. It will be appreciated that once the spring strip 15 has been slightly extended the spring strip 15 provides an upward bias to the carriage 8, and the magnitude of that upward bias is not dependent upon the position of the carriage 8, i.e. is not dependent upon the amount of extension of the spring strip 15. The strength of the spring strip 15 is thus selected, in any particular instance, substantially to balance the downward bias exerted on the carriage 8 by means of the seat belt retractor reel (which is not shown). Thus, movement of the carriage both upwards and downwards is facilitated, since such movement of the carriage is then effected in substantially bias-free conditions. This ease of adjustment will encourage users to adjust the seat belt according to their size or height, leading to greater comfort and, in the event of an accident, greater safety. Whilst the invnetion has been described with reference to an embodiment to be mounted on a "B" post for use with a front seat belt, the invention may equally be used with a rear seat belt.

Claims: A seat belt arrangement comprising a guide element(11) through which part of the seat belt passes, the guide element being mounted on a carriage(8) that is movable along a rail(1) or the like, the carriage being provided with means(9) to selectively retain or lock the carriage in a plurality of positions along said rail, means(15) being provided to impart a bias to the carriage against any bias applied thereto by the seat belt, characterised in that said bias imparting means comprising a spring strip(15), said spring strip having an initial linear portion(17) which merges into a spirally wound portion(18) so that the linear portion is tangential to the outermost turn of the spirally wound portion, the opposed ends of the spring strip(15) being respectively connected to the carriage and retained at a substantially predetermined position. A seat belt arrangement according to Claim 1 wherein the spirally wound portion is retained within a cavity(19). A seat belt arrangement according to claim 2 wherein the cavity(19) is defined by a housing(20) which is retained at a substantially predetermined position. A seat belt arrangement according to claim 3 wherein said carriage(8) is provided with a hook-like element(14) which engages an aperture(16) formed in an end portion(17) of the spring strip(15). A seat belt arrangement according to any one of the preceding claims wherein the spring strip(15) is formed of steel. A seat belt arrangement according to any one of the preceding claims wherein the spring strip(15) is of substantially rectangular cross section. A seat belt arrangement according to any one of the preceding claims wherein said rail(1) comprises a channel along which the carriage(8) may slide, the channel being provided with a plurality of apertures(7) therein and the carriage being provided with releasable means(9) to engage said apertures, to constitute the means to retain or lock the carriage in said positions.

Inventors: GRUNEWALD, HANS-JOACHIM
Applicants: AUTOLIV DEVELOPMENT AKTIEBOLAG
Application year: 1985
Main classification: B60R22
IPC codes: B60R22