GB2123269A - Safety belt anchorage - Google Patents

Abstract

A three-point type vehicle safety belt, which has at one side of the vehicle seat an upper 2 and a lower anchor point 1 and an inertia reel for withdrawal of the belt strap towards said upper anchor point 2, and at the other side of the vehicle seat a lower anchor point in which the belt strap is detachably anchored. The belt strap 8 forms a chest portion extending between the upper anchor point 2 at said one side and the anchor point at said other side, and a hip portion 7 extending between the lower anchor point 1 at said one side and the anchor point at the other side. The lower anchor point at said one side is provided at one end of an arm 16 mounted in the vehicle for pivotal movement between front and rear positions as seen in the longitudinal direction of the vehicle. One end of a spring 17 is connected to an attachment 22 on the arm 16 which is displaceable in a path 23 extending along the arm 16 at each side of the pivot axis thereof, while the other end 19 of the spring 17 is connected to the vehicle so as to bias the arm towards the front or rear position (shown) at one side and the other, respectively, of an intermediate dead center position of the arm. <IMAGE>

Description

SPECIFICATION A three-point type vehicle safety belt The present invention relates to a three-point type vehicle safety belt, which has at one side of the vehicle seat an upper and a lower anchor point and an inertia reel for withdrawal of the belt strap towards said upper anchor point, and at the other side of the vehicle seat a lower anchor point in which the belt strap is detachably anchored, the belt strap forming a chest portion extending between the upper anchor point at said one side and the anchor point at said other side, and a hip portion extending between the lower anchor point at said one side and the anchor point at said other side, wherein the lower anchor point at said one side is provided at one end of an arm mounted in the vehicle for pivotal movement between front and rear positions as seen in the longitudinal direction of the vehicle, and wherein one end of a spring is connected to an attachment on the arm and the other end thereof is connected to the vehicle to bias the arm towards the front or rear position at one side and the other, respectively, of an intermediate dead center position of the arm.

In two-door vehicles wherein the back seat is reached through the door openings arranged at opposite sides of the front seats, the safety belts for the persons occupying the front seats can be of the kind referred to above in order to obtain a proper force geometry when the safety belts are being used, and to facilitate for the rear seat passengers to enter and leave the vehicle.

The purpose of the invention is to provide a three-point vehicle safety belt of the kind referred to, which makes possible to adjust the bias provided by the spring in the front and rear positions of the arm, to a proper value.

For this purpose the safety belt of the invention is characterized in that the attachment for said one end of the spring is displaceable in a path extending along the arm at each side of the pivot axis thereof.

By this arrangement the spring bias can be adjusted by appropriately dimensioning the extension of said path at one side and the other, respectively, of the pivotal axis of the arm.

In order to illustrate the invention one embodiment thereof will be described below reference being made to the accompanying drawings in which Figure 1 is a side view of the vehicle safety belt of the invention when in use, and Figure 2 is a side view of the safety belt when not in use.

The three-point vehicle safety belt shown in the drawings is mounted in a two-door vehicle fragmentarily indicated by dot-and-dash lines, and has a lower anchor point 1 and an upper anchor point 2 for the belt strap 7 on the vehicle side wall at one side of the associated front seat (not shown) and a lower anchor point (not shown) at the opposite side of the seat. In said latter anchor point, the belt strap is detachably anchored by means of a belt lock including a lock tongue 6 on the strap. The belt strap extends between the anchor points 1 and 2 as a continous loop to form, when in use, between the anchor point 1 and the anchor point at said opposite side of the seat a hip strap portion,. and between the anchor point 2 and the anchor point at said opposite side of the seat a chest strap portion.The anchor point 2 comprises a run-through mounting from which the belt strap extends at 8 to an inertia reel (not shown) mounted in the vehicle. As will be understood the safety belt of the invention as described so far is of a design well known in the art.

At the anchor point 1 the belt strap 7 is connected to an arm 16 which is pivotally mounted in the vehicle by means of a bolt 15 fastened to the side wall below the entrance opening therein, indicated at 18, to be pivoted between a front position of Figure 1, occupied when the safety belt is being used, and a rear position of Figure 2, occupied when the safety belt is inoperative. The arm is biassed by a spring element 17 such as a helical tension spring or a resilient string or the like.One end 19 of the spring element is attached to a rear fixed fastening point 20 in the vehicle e.g. on the side wall thereof, while the opposite end 21 of said element is attached to a slide 22 which its displaceable at low friction in a linear guide slot 23 extending along the arm, between end stops 24 and 25 at one end and the other, respectively, of the slot, located one at each side of the pivotal axis of the arm, defined by the bolt 15. The end of the strap 7 forms a fastening loop 27 passing through an opening 28 at one end of the arm 16.

When the safety belt is being used the arm 16 extends substantially in the load direction of the safety belt, Figure 1. Then, the slide 22 is in a lower position engaging the end stop 24, below the pivot axis defined by the bolt 15. In this position, the spring bias tends to keep the arm in the operative position shown in Figure 2, but the biasing force should be relatively light in relation to the pulling force exerted on the belt strap by the inertia reel so as not to swing the arm in clockwise direction as seen in Figure 1 against the pulling force provided by the inertia reel.

Thus, it will be seen that the safety belt when it is being used will maintain a correct force geometry for a proper function.

When the safety belt is unlocked to be detached from the anchor point at said-opposite side of the seat, the belt strap 7 will be withdrawn by the inertia reel to take a position in which the strap extends substantially vertically between the anchor points 1 and 2 along the side wall of the vehicle as shown in Figure 2.

During an initial part of the withdrawal of the strap the safety belt will take the position shown by dot-and-dash lines in Figure 1, under the bias of the inertia reel, the arm 16 being pivoted in counterclockwise direction against the bias of the spring element 17. In this position, the pulling force of the spring element is perpendicular to the arm 16 and extends through the pivot axis (bolt 15) of the arm.

However, due to inertia the arm 16 will move slightly beyond the said dead center position and then the bias of the spring element will cause the slide 22 to move along the guide slot 23 towards the end stop 25. With the slide engaging the end stop 25 the spring element will bias the arm 16 so as to swing the arm in counter-clockwise direction against the bias of the inertia reel to the position shown in Figure 2. In this position, the arm is held substantially horizontal below the door sill of the door opening 18 and the belt strap completely clears said opening so as to facilitate for the back seat passengers to pass through the door opening.

When the safety belt is to be used again, the -lock tongue 6 is gripped in the conventional manner and the belt strap is withdrawn from the inertia reel against the bias thereof to be locked to the anchor point at the side of the front seat which is opposite to the vehicle side wall. Then, the arm 16 will be pivoted in the clockwise direction against the bias of the spring element 17, the slide 22 will be displaced in the guide slot 23, and when it has passed the dead center position, the arm will again take the position of Figure 1.

As will be realized it is possible to adjust the force acting on the arm 16 in the two end positions thereof by appropriately dimensioning the extension of the slot 23 on opposite sides of the bolt 15 defining the dead center position of the arm, and thus the lever arm over which the spring element 17 acts on the arm 16 at the end stops 24 and 25, respectively.

The invention described herein can be modified within the scope of the claims. Thus, the spring elemerit 17 can comprise a pressure spring engaged between the slide 22 and a fixed attachment point forwardly of the bolt 15. Instead of being guided in a slot the slide can be mounted for displacement on a guide bar or rib on the arm 16.

Claims (3)

1. A three-point type vehicle safety belt, which has at one side of the vehicle seat an upper and a lower anchor point and an inertia reel for withdrawal of the belt strap towards said upper anchor point, and at the other side of the vehicle seat a lower anchor point in which the belt strap is detachably anchored, the belt strap forming a chest portion extending between the upper anchor point at said one side and the anchor point at said other side, and a hip portion extending between the lower anchor point at said one side and the anchor point at said other side, wherein the lower anchor point at said one side is provided at one end of an arm mounted in the vehicle for pivotal movement between front and rear positions as seen in the longitudinal direction of the vehicle, and wherein one end of a spring is connected to an attachment on the arm and the other end thereof is connected to the vehicle to bias the arm towards the front or rear position at one side and the other, respectively, of an intermediate dead center position of the arm, characterized in that the attachment for said one end of the spring is displaceable in a path extending along the arm at each side of the pivot axis thereof.

2. A safety belt as claimed in claim- 1, characte rized in that the path is formed by a guide and that the attachment comprises runner displaceable along said guIde.

3. A safety belt as claimed in claim 2, characterized in that the guide comprises a slot in the arm, extending in the longitudinal direction thereof.