Device for anchoring one end of a motor vehicle seat belt

Abstract: The invention relates to a device for anchoring the end (1) of a seat belt comprising an essentially axial rail (2) anchored to the bodywork of the vehicle, a runner (3) connected to this end and provided with constraint means (4) designed to allow the runner to move longitudinally relative to the rail and to prevent the runner from separating from the rail under the action of the forces which normally act on the end of the belt in the working conditions, a jamming member (7) hinged to the runner and provided with an active surface (9) designed to press on one of the surfaces of the rail (2), and a spring (14) interposed between the runner (3) and the jamming member (7), the action of the spring (14), the shape of the active surface (9) and the position of the axis of the hinge (8) being designed such that when the runner moves in one direction relative to the rail and the force applied to the end (1) of the belt overcomes the opposition of the spring (14), the jamming member (7) turns, thus preventing the runner from moving in this direction.

Description: The present invention relates to a device for anchoring one end of a motor vehicle front seat belt, by means of which it is possible to position this end where desired relative to the bodywork, especially for gaining easy access to the rear seats in cars with front doors only. As is known, the end of a seat belt for a front seat of a motor vehicle is normally anchored permanently to the bodywork at a point positioned behind this seat. Such a mounting presents a number of drawbacks. In the first place, the position of the point of attachment of this end of the belt may not be the most suitable for certain positions of the seat, in some of which the angle of the portion of belt running between the point of attachment and where it passes around the body of the passenger may not be the most suitable for it to pass properly around the body and for proper transmission of the forces along this belt portion when the belt is under working conditions. Moreover, the point of attachment of this end may present an obstacle to easy access to the rear seats of the vehicle, especially in cars with front doors only. These problems are partially solved by EP-A-0098458 wherein the seat belt is anchored to an element rigid with the seat and in sliding connection with a cable anchored to the bodywork of the vehicle. Anyway, this solution, thus allowing adjustment of the axial position of the seat belt anchoring, does not allow easy access to the car seats in a vehicle with front doors only. The object of the present invention is to provide a device for anchoring one end of a motor vehicle seat belt, by means of which these drawbacks are eliminated and which makes it possible, therefore, to move the anchoring point of this end to the bodywork, within a range of predetermined values. This object is achieved by means of a device for anchoring one end of a motor vehicle seat belt, as claimed in Claim 1. In order to assist with understanding the structure and modes of operation of the device of the present invention, a more detailed description will now be given, by way of example, with reference to the figures of the attached drawings, in which: Figure 1 is a perspective view of the anchoring device of the invention; Figure 2 is a side view of the same; and Figure 3 is a vertical section on the cutting plane III-III. The device is for anchoring the end of the seat belt of a front seat of a motor vehicle (these are normally anchored to the floor of the motor vehicle in the case of front belts), which in Figure 1 bears the reference 1. The device comprises an essentially axial rail 2 formed by a rigid bar anchored to the bodywork of the vehicle, a runner 3 connected to the end 1 of the belt and provided with constraint means, marked 4 as a whole, designed to allow the runner to move longitudinally relative to the rail and to prevent the runner from separating from the rail under the action of the forces which act on the end 1 of the belt under normal working conditions. Advantageously, these constraint means may basically be formed (as in the case of the embodiment illustrated in the drawings) by a channel-shaped part 5 connected in a sliding manner to the rail 2, and this rail 2 may advantageously be formed by a prismatic bar. Advantageously, the runner 3 is made from a metal plate bent into an approximate U, which gives a pair of wings 6 held apart by rivets each having a distance piece 6a; between the U part and the rail 2 is a sliding strip 2a. The device also comprises a jamming member 7 connected by a hinge 8 to the runner 3 and provided with an active surface 9 (Figure 2) designed to press on the outer surface of the rail 2 and at least one spring 14 interposed between the runner 3 and the jamming member 7. The action of the spring 14, the shape of the active surface 9 and the position of the axis of the hinge 8 are designed such that when the runner 3 runs along the rail 2 in normal belt-moving operations, the jamming member 7 is held in a rotated position in order that the active surface 9 is held off the surface of the rail 2 and that when the force applied to the end of the belt 1 overcomes the opposition of the spring 14, in a first direction of movement of the runner 3 relative to the rail 2 (movement towards the left in Figure 2), it turns the jamming member and jams this active surface against the surface of the rail, and thus prevents the runner from moving relative to the rail in this first direction; whereas when the runner moves in the opposite direction to the aforesaid direction this movement is always permitted (movement of the runner towards the right in Figure 2). The end 1 of the belt is preferably hinged to the jamming member 7 at a point 10 which, relative to the hinge 8, is on the opposite end from the active surface 9 of the jamming member 7, so that the forces acting on the end 1 in the working conditions of the belt turn the jamming member 7, in the anticlockwise direction in Figure 2, bringing the active surface 9 into contact with the surface of the rail 2. The end 1 of the belt is advantageously anchored to an attachment member 13 which in turn is hinged at the point 10 to the jamming member 7, as can be clearly seen in Figure 2. Furthermore, at least one spring 14 is interposed between the runner 3 and the jamming member 7 and is designed to keep the jamming member turned clockwise as seen in Figure 2, in a position in which the active surface 9 is not in contact with the surface of the rail 2. The jamming member 7 is advantageously in the form of a plate, as is clearly visible in Figure 2, and the active surface 9 of this member is formed by a shaped surface of the plate itself; this plate is also positioned between the two wings 6 of the runner 3 (Fig. 3). Advantageously, as has been shown in Figure 3, the jamming member 7 is hinged to the runner 3 by means of a nut and bolt 16 passing through corresponding holes in the wings 6 and in this member; furthermore, a bush 17 is positioned between the shank of the bolt and the jamming member 7 and the nut 18 on this bolt is welded to one of the wings 6. Likewise the attachment member 13 at the end of the belt 1 is in the form of a plate and is hinged to the jamming member 7 by another nut and bolt 19, which passes through corresponding holes in these members; the nut 20 on this bolt is welded to the jamming member 7 and another bush 21 is fitted between the shank of this bolt and the hole of the attachment member 13. The spring 14 is advantageously a helical spring working in torsion, whose turns 22 (Fig. 3) are positioned around the head of the bolt 16 and whose ends are fixed, one, 23, to the jamming member 7 and the other, 24, to one wing 6 of the runner 3. As an essential feature of the invention, the seat equipped with the described device is supported by a runner 26 able to move along a corresponding rail 27, which is independent of rail 2 and parallel thereto. Advantageously forming part of the invention is also a connecting part 25 (Fig. 1) designed to determine, when the belt is fitted around the user, the position of the runner 3 relative to the seat in order to obtain the correct configuration of the belt for every position of this seat; this connecting part 25 can be seen in Figure 1 and consists basically of an arm anchored to runner 26 connected to the seat and able to move along the corresponding rail 27. The device described works in the following manner. When runner 26 is moved frontwards for accessing the rear seats, also the runner 3 can be moved by hand along the corresponding rail 2 to put it in a predetermined position where it will not be an obstruction, for example to a passenger getting into the rear seat of a motor vehicle. Such movement is possible in either direction along the rail because, in the rest position, the spring 14 keeps the jamming member rotated so that the active surface 9 of the member 7 is kept off the corresponding outer surface of the rail 2. Consequently the resisting force generated by the movement of the runner depends only on the friction in the connection between the strip 2a and the rail, which is obviously very low. Moreover, if the device is provided with the connecting part 25 (Figure 1), the runner 3 can be moved frontwards (towards the left in Figure 2) till against part 25 and to the position of easy access to the rear seats, in the case of for example cars with only front doors (towards the right in Figure 2), in whatever position the front seat is placed, and may optionally have an auxiliary spring return system. When the front seat is returned in its normal position part 25 automatically brings runner 3 to the correct belt-wearing position. If the belt is being worn by the occupant and its end 1 is subject to a force produced by, for example, a sudden forward movement of the occupant which must be restrained by the belt, this force is transmitted through the attachment member 13 to the jamming member 7 and acts on the point 10 where the member 13 is hinged to the member 7. This force therefore turns the jamming member 7 anticlockwise in Figure 2, overcoming the elastic resistance of the spring 14 and consequently bringing the active surface 9 of the jamming member against the surface of the rail 2. Because of the shape of this surface and the position of the axis of the hinge 8, the consequence is that, whatever force is applied by the end of the belt 1, the jamming of the active surface 9 of the jamming member 7 against the surface of the rail 2 generates a reaction whose component in the direction of the rail 2 prevents the runner 3 from moving along the rail towards the left of Figure 2.

Claims: Device for anchoring one end (1) of a motor vehicle front seat belt, comprising: an essentially axial rail (2) anchored to the bodywork of the vehicle, characterized in that a runner (3) connected to said end of the belt and provided with constraint means (4) is designed to allow the runner to move longitudinally relative to the rail and to prevent the runner from separating from the rail under the action of the forces which normally act on said end of the belt in the working conditions of the belt; a jamming member (7) hinged (8) to said runner (3) and provided with an active surface (9) designed to press on one of the surfaces of said rail (2); an opposing spring (14) inserted between said runner (3) and said jamming member (7), the action of said spring (14), the shape of said active surface (9) and the position of the axis of said hinge (8) being designed such that when the runner runs along the rail (2) in normal belt-moving operations, said jamming member (7) is held in a rotated position in order that said active surface (9) is held off said surface of the rail (2) and that when the force applied to the end of the belt (1) overcomes the opposition of the spring (14) in a first direction of movement of the runner relative to the rail (2), it turns said jamming member (7) and jams said active surface (9) against said surface of the rail (2), thus preventing the runner (3) from moving relative to the rail (2) in said first direction, whereas when said runner (3) moves along said rail in a second direction opposite to the first, this movement is always permitted; and in that said axial rail (2) is independent of an anchoring rail (27) for the front seat. Device according to Claim 1, characterized in that said end (1) of the belt is hinged to said jamming member (7) at a point (10) which, relative to said hinge (8), is on the opposite end from said active surface (9) of the jamming member (7), so that said forces acting on said end (1) turn said jamming member (7), bringing said active surface (9) into contact with said surface of the rail. Device according to Claim 2, characterized in that said end (1) of the belt is anchored to an attachment member (13) which in turn is hinged to said jamming member (7) at said point (10). Device according to one of the previous claims, characterized in that it comprises a connecting part (25) for positioning said runner (3) relative to a seat of the vehicle in order to obtain the correct position of the belt for every position of the seat. Device according to one of the previous claims, characterized in that said runner (3) comprises a channel-shaped part (5), inside which said rail (2) is held and slides and which is provided with at least one wing (6) to which said jamming member (7) is hinged. Device according to one of the previous claims, characterized in that said jamming member (7) is in the form of a plate, said active surface (9) being formed by a shaped edge of said plate. Device according to one of the previous claims, characterized in that said runner (3) is formed by a metal plate bent into an approximate U to give said tubular part (5) and a pair of wings (6), said plate (7) being arranged between said two wings (6) and being hinged to them by a first nut and bolt (16). Device according to one of the previous claims, characterized in that said member (13) for attaching the end (1) of the belt is hinged to said plate (7) by a second nut and bolt (19). Device according to one of the previous claims, characterized in that said spring (14) is a helical spring working in torsion, whose turns (22) are positioned around the head of said first bolt (16) and whose ends (23, 24) are fixed, one to said jamming member (7) and the other to said wing (6).

Inventors: RICHIARDI SILVIO, RICHIARDI, SILVIO
Applicants: FIAT AUTO SPA, FIAT AUTO S.P.A.
Application year: 1995
Main classification: B60R22
IPC codes: B60R22