THREE-POINT SAFETY BELT ASSEMBLY FOR A VEHICLE

Abstract: Three-point safety belt assembly having both belt ends attached to a point at a door-post, a rotatable arm (1) at­ tached to the door-post at a higher point which is rotatable between a vertical rest position and a horizontal active po­ sition, and provided with belt guiding means (9, 10) rotatable about the arm (1), and with a rotatable sliding eye (4) for the belt, in which the eye is slidable along the belt and can be attached to a point opposite the door-post wherein the arm (1) is provided with a helical spring (6) one point of attach­ ment of which is located with regard to the other point of at­ tachment so that the tangential component of the tension force of the spring (6) in the horizontal extreme position of the arm (1) is larger than and directed oppositely to the same component in the vertical extreme position of the arm (1).

Description: Three-point safety belt assembly for a vehicle The invention relates to a three-point safety belt assemby for a vehicle, in which both belt ends have been attached to a point at or near a door-post of the vehicle and where an automatic belt coiling device may be located for one of the belt ends and in which at a higher point of the door-post that is located when in use about at shoulder level of a person seated there a rotatable arm is attached to the door-post which arm is rotatable between a substantially vertical rest position and a substantially horizontal active position, which arm is provided with a belt guiding means rotatable about the longitudinal axis of the arm, and in which point is also rotatably located a sliding eye for the belt, and in which a sliding eye with attachment means is present which is slidable along the belt and can be attached to a point located at the side opposite the doorpost of a seat located there. A three-point safety belt assembly provided with a swinging arm is known from German Auslegeschrift 2360702. It is applied in particular in two door motor cars, because there normally exists the drawback that the driver or the passenger next to the driver has to reach far behind to get to the belt. The fact is that the door of a two door car is normally relatively wide so that the doorpost to the upper part of which the three-point belt is attached is located relatively far to the back with regard to the relative person. For this reason this point of the belt is not attached directly to this post by way of a sliding eye but by intermediary of a swinging arm as German Auslegeschrift 2360702 shows. This is also shown in German Auslegeschrift 2541647. Moreover the sliding eye of the safety belt is attached to the arm so as to be rotatable about the longitudinal axis of the arm, so that the belt in use can adept its position to the relative person. The known swinging arms have the drawback that they have no well defined positions. By this is meant that they can remain in any position. This can be objectionable also if a back seat passenger gets into the car, whereas a fixed (more a less horizontal) position during use provides more certainty as to an effective safety. The object of the invention is to meet these objections so that the swinging arm can easily be brought into two extreme positions and kept therein. If a driver (or the passenger next to him) gets in he can have the arm swing forward to a substantially horizontal position upon a light touch, which causes at the same time the safety belt with its sliding eye to move forward. In accordance with the invention this is brought about if the arm is provided at some distance form its point of rotation with a point of attachment for one end of a helical spring which point of attachment is located in such a way with regard to a point to which the other end of the spring is fixed to a part of the vehicle body and the centerline of the point of rotation of the arm that the tangential component of the tension force of the spring in the horizontal extreme position of the arm is larger than and directed oppositely to the same component in the vertical extreme position of the arm. The two extreme positions of the arm should be limited preferably by the provision of stops. The first point of attachment mentioned of the end of the helical spring may be a part of the arm for example in the form of an eye but may also be located in or on a plate attached to the arm, which plate is also rotatable about the point of attachment. It has been found that it is desirable for an efficient an easy functioning of the assembly of rotatable arm and belt that this guiding means funtions very smoothly. For that purpose and in accordance with the invention the free end of the arm is provided with a fork rotatable about the longitudinal axis of the arm and a guide roller for the belt is mounted therein and is rotatabe about its longitudinal axis. The arm preferably has a bent form and is thereby adapted to local circumstances for optimal guidance of the belt. The asymmetric form with regard to the centerline of the arm guaranties a good guiding and passage of the safety belt. The invention is further explained with a drawing. This shows in: Fig. 1 a view of a swinging arm according to the invention in its extreme positions; and Fig. 2 is a section of the same swinging arm. Fig. 1 and fig. 2 show that the swinging arm 1 is rotatably connected to the attachment bolt 2. Rotatable about the bolt 2 are also a plate 3 and the sliding eye 4 for the safety belt (not indicated) movably attached to the plate. The arm 1 has an attachment point 5, respectively 5' for the end of a helical spring 6, respectively 6'. This spring 6 has been fixedly connected at a point 7 to a point of the car body. Fig. 1 shows that the force A of the spring 6 can be resolved into a force B through the point of rotation of the arm 1 with centerline 8, 8' and a force C acting perpendicular to force B. This force forces the arm 1 into an extreme position (drawn with unbroken lines). The same can be represented for the position 1' of the arm. The spring is located in position 6' with point of attachment 5'. A similar diagram of forces can be drawn, which shows that a force C' which is larger than force C again acts in a tangentional direction but now into the direction of the other extreme position. In a direct line with the centerline 8 mentioned and immovable in the direction of this axis is rotatably fixed a guiding piece 9, 10 with fork shaped part 9 between which is attached a rotatable guiding roller 10 for the purpose described above.

Claims: Claims: 1. Three-point safety belt assembly for a vehicle, in which both belt ends have been attached to a point at or near a door-post of the vehicle and where an automatic belt coiling device may be located for one of the belt ends and in which at a higher point of the door-post that is located when in use about at shoulder level of a person seated there a rotatable arm is attached to the door-post which arm is rotatable between a substantially vertical rest position and a substantially horizontal active position, which arm is provided with a belt guiding means rotatable about the longitudinal axis of the arm, and in which point is also rotatably located a sliding eye for the belt, and in which a sliding eye with attachment means is present which is slidable along the belt and can be attached to a point located at the side opposite the door-post of a seat located there, characterized in that the arm (1) is provided at some distance from its point of rotation (2) with a point of attachment (5) for one end of a helical spring (6) which point of attachment is located in such a way with regard to a point (7) to which the other end of the spring (6) is fixed to a part of the verhicle body and the centerline of the point of rotation (2) of the arm (1) that the tangential component (C) of the tension force of the spring (6) in the horizontal extreme position of the arm (1) is larger than and directed oppositely to the same component in the vertical exteme position of the arm. 2. Three-point safety belt assembly according to claim 1, characterized in that both extreme positions of the arm are limited by stops. 3. Three-point safety belt assembly according to claim 1 or 2, characterized in that the helical spring (6) has been attached to the arm (1) via a plate which is rota table about the point of attachment (2). 4. Three-point safety belt assembly according to any one of the preceding claims, characterized in that the free end of the arm (1) is provided with a fork (9) rotatable about the longitudinal axis (8) of the arm (1) and a guide roller (10) for the belt is mounted therein and is rotatable about its longitudinal axis. 5. Three-point safety belt assembly according to any one of the preceding claims, characterized in that the arm (1) has been bent inwardly over at least a part of its longitudinal axis (8', 8").

Inventors: VAN DER WIEL, JOHANNES WILLEM
Applicants: VOLVO CAR B.V.
Application year: 1986
Main classification: B60R22
IPC codes: B60R22