Chairs and seats – Body or occupant restraint or confinement – Safety belt or harness; e.g. – lap belt or shoulder harness
Reexamination Certificate
1999-04-15
2001-07-24
Barfield, Anthony D. (Department: 3636)
Chairs and seats
Body or occupant restraint or confinement
Safety belt or harness; e.g., lap belt or shoulder harness
C297S478000, C297S216130
Reexamination Certificate
active
06264280
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a safety belt arrangement for vehicles. More particularly, the present invention has application to the field of safety belts which are provided with a pretensioning device.
BACKGROUND OF THE INVENTION
In the field of motor vehicles, it is common to use safety belts comprising a retractor device which is fixed to the floor of the vehicle or in the so-called B-post (i.e. the post which is formed by the bodywork to the side of each front seat), and a seatbelt strap running from the retractor device and across the body of the user. Normally, a guiding device for the strap is arranged at the same level as the shoulder portion of the user. The safety belt is locked in an anchor on the vehicle's floor. In safety belts of the so-called three-point type, the strap is also guided about the anchor, allowing it to run across the waist of the user.
As regards operation of a safety belt, certain demands and requirements exist. Firstly, it is important that the guiding device is arranged so that the strap is guided in a position which is close to the shoulder portion of the user, i.e. in a position which is adapted to the height of the user. In this manner, optimum protection can be provided in the event of a collision. Furthermore, there is a need for a guiding device which provides height adjustment, i.e. which allows individual setting of the position of the guiding point. In particular, there is a demand for an automatic height adjustment device, relieving the user from having to adjust any control or the like in order to set the guiding device in a correct manner.
Furthermore, there is often a requirement that the safety belt should comprise some type of pretensioning device which, in a known manner, is adapted to tension the belt in the event of a collision. In this regard, the strap is intended to be tightened against the upper torso of the user immediately after the collision, i.e. before the user is urged forwards due to his weight. In this manner, the pretensioning device can prevent or reduce personal injuries in connection with collisions. A device for pretensioning a strap by means of a pyrotechnic pretensioner is known from European Patent No. 138,507.
Furthermore, there is a demand for a force-limiting operation of the safety belt in the event of a collision. This means that the safety belt should not be completely unyielding. Instead, it should absorb part of the energy which is developed when the user is urged forwards during heavy retardation.
In recent years, safety belts have been developed in which both the retractor and the guiding device are integrated into the backrest of the vehicle seat (so-called “belt-in-seat” devices), i.e. the retractor of the safety belt is not fixed to the body of the vehicle but instead to the vehicle seat. Such systems provide improved comfort and protection since the strap will always be in the same position in relation to the user, independently of the position of the vehicle seat. Furthermore, a simplified design for the B-post can be provided, as regards the technological demands, the space available and the design, since in this case the B-post does not have to be provided with any belt retractor and guiding device. Finally, a shorter strap can be used, which lowers the costs and decreases the risk for a “film-reel” effect to occur in the retractor. This means that a small amount of the strap is fed out due to the fact that it is packed on the retractor, in spite of the fact that the strap is locked.
Several types of height adjustment devices, pretensioning devices and force-limiting devices are known. However, a problem in connection with today's safety belts resides in the fact that they do not allow a plurality of functions to be integrated into the same construction. This problem implies that today's systems often become space consuming as well as costly. In particular, this is a problem in connection with the socalled “belt-in-seat” devices.
SUMMARY OF THE INVENTION
A main object of the present invention is therefore to provide an improved device in connection with safety belts for motor vehicles, into which a plurality of functions can be integrated and which also constitutes a simple, compact and low-cost unit.
In accordance with the present invention, this and other objects have now been realized by the invention of a safety belt device for vehicles comprising a seat belt, a retractor for retracting the seat belt, a seat belt guide for guiding the seat belt, a displacement member for displacing the seat belt guide between a normal operating condition and a tightened condition for the seat belt, the displacement member comprising a rotatable drum upon which the seat belt guide is mounted, and an activator for activating the displacement member into the tightened condition, the displacement member including energy absorbing means for reducing the force exerted upon the seat belt guide by the seat belt during return of the seat belt guide from the tightened condition to the normal operating condition. In one embodiment, the activator causes rotation of the rotatable drum.
In accordance with one embodiment of the safety belt device of the present invention, the retractor includes a central axis of rotation and the rotatable drum includes a central axis of rotation, the seat belt guide extending in a direction substantially parallel to the central axes of rotation of the retractor and the rotatable drum.
In accordance with another embodiment of the safety belt device of the present invention, the energy absorbing means comprises a pin associated with the rotatable drum and a slot cooperating with the pin. In a preferred embodiment, the safety belt device includes a bracket supporting the rotatable drum, the bracket fixedly mounted with respect to the vehicle, the pin protruding from the rotatable drum and the slot disposed in the bracket.
In accordance with another embodiment of the safety belt device of the present invention, the rotatable drum is adapted to displace the seat belt guide along a circular arc.
In accordance with another embodiment of the safety belt device of the present invention, the activator activates the displacement member into the tightened condition in response to a collision of the vehicle. In a preferred embodiment, the safety belt device includes an acceleration sensor mounted in the vehicle, the activator comprising a pyrotechnic pretensioning device activated by means of the acceleration sensor.
In accordance with the present invention, a vehicle seat is also provided including a safety belt device as set forth above.
The present invention comprises a combined guiding, pretensioning and force-limiting apparatus, which preferably is integrated with the vehicle seat. In this manner, a high degree of comfort and protection for the user can be provided.
REFERENCES:
patent: 4310176 (1982-01-01), Furusawa et al.
patent: 5088794 (1992-02-01), Iwami et al.
patent: 5294150 (1994-03-01), Steffens, Jr.
patent: 5716102 (1998-02-01), Ray et al.
patent: 42 06 093 C1 (1993-07-01), None
patent: 0 138 507 A2 (1985-04-01), None
AB Volvo
Barfield Anthony D.
Royston, Rayzor, Vickery, Novak & Druce, L.L.P.
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