Chairs and seats – Movable bottom – Movable independently of back
Reexamination Certificate
1999-02-17
2001-10-09
Cranmer, Laurie K. (Department: 3624)
Chairs and seats
Movable bottom
Movable independently of back
C297S344150, C297S473000, C248S419000, C248S420000
Reexamination Certificate
active
06299252
ABSTRACT:
The invention relates to a seat underframe of a motor vehicle seat according to the generic part of Claim
1
.
FIELD OF THE INVENTION
Motor vehicle seats of this type are generally equipped with a safety belt, which, from the state of the art, consists of a lap belt and a shoulder belt. The two run together in a v-shaped manner, conjoining in a plug-in part which can be inserted into a belt. The other end of the lap belt is, in a preferred embodiment, secured to the motor vehicle seat itself. The other end of the shoulder belt is usually allocated to the car body, although it may otherwise be attached to the back rest in the case of what is known as an integral moulded seat.
BACKGROUND OF THE INVENTION
In the case of motor vehicle seats, there is a growing tendency to equip the seat base with height adjustability with respect to the seat travel device for longitudinal adjustments consisting of two pairs of runners. In the case of a seat underframe of the above-mentioned kind, the height adjustment device has rear rockers, namely a left-hand and a right-hand rear rocker. They support the seat base in its posterior area. The seat base must also be supported in its front area. It is also possible to provide rockers, namely front rockers, which are nevertheless devices of different construction, such as, for example, curved guide rails for axle pins on the front edge of the seat, etc.
A high level of safety is required of seat underframes, in particular, the safety belt must be anchored to them in such a fashion that the entire vehicle seat is capable of withstanding the loads which it is subjected to during the prescribed test trials. The construction of the seat underframe must also be of such a type as to be of as low a total weight as possible, capable of being set up and mounted simply, in addition to being easily recyclable. The mounting points for the safety belt, especially for the lap belt, must be embodied and arranged in such a way that their configuration is serviceable on the one hand and that the components into which the forces released by an accident are to be induced, on the other hand, are able to absorb these forces well without having to be of heavy construction with dimensions which are too large, resulting in a weight that is too high.
This is where the invention starts. It is the task of the invention to further develop the seat underframe of the above-mentioned kind in such a way, that the safety belt, especially the lap belt of this safety belt, is positioned in such a fashion as to be not only convenient to the user but also capable of absorbing high forces arising in the course of an accident, the individual components being of reasonable dimensions.
SUMMARY OF THE INVENTION
Departing from the seat underframe of the above-mentioned kind, this problem is solved in the following manner, that the rocker of the seat runner located on the vehicle exterior side, is equipped with an area of attachment for the lap belt of the safety belt, situated between both rocker hinges of this rocker, nearer to the upper rocker hinge than to the lower rocker hinge.
According to the invention, it is therefore the free end of the lap belt which is caught up by the outer rocker located on the vehicle exterior side. There, an area of attachment is provided, at which the afore-mentioned end of the lap belt is arranged. This area of attachment is not located at the seat base and not at the seat runner, but within a specific position of the back rocker. Because of this, the area of attachment varies on the one hand only to an insignificant degree in the event of a height adjustment of the seat base, in any case to a degree distinctly less than that of a belt end stationarily affixed to a seat runner. On the other hand, however, the induced forces are to be handled in this connection in such a way that the individual components of the seat underframe which play a role in the transference of forces released by an accident, particularly the posterior rocker, may be given normal dimensions. Because the end of the lap belt does not act upon the upper end entirely, but consequently, upon the upper rocker hinge instead, the interplay of leverages is still favorable, and the posterior rocker can alter its shape under the influence of the forces released by an accident, its stability capable of being exploited to its full extent, without the seat base and a tie-bar joining both rockers in the upper area having to be embodied in an unnecessarily prominent, heavy fashion.
The invention thus presents a particularly favorable arrangement of the free end area of the lap belt. This arrangement represents a felicitous compromise between an easy-to-use configuration and a favourably high-stability configuration.
The area of attachment is generally embodied as an aperture. Through this aperture, a bolt, for example, is inserted, with which the suitably embodied free end of the lap belt engages, the bolt, for instance, penetrating the free end.
In a preferred embodiment, the area of attachment to be found on a dome-shaped bulge which is fashioned in such a way that it protrudes in the direction of the vehicle's exterior side. In particular, a molding is to be considered in this connection. Thanks to the dome-shaped bulge, the course of the lap belt is more convenient, as it runs from the seat essentially only in a downward direction, its course in any case now running without a component tending towards the middle of the seat. Due to the dome-shaped bulge, room for sufficient play in the course of the movement of the height adjustment is achieved.
In a particularly preferred embodiment of the invention the area of attachment for the free end of the lap belt is found in a distance from the upper rocker hinge smaller than one third of the distance between the two rocker hinges. The nearer the area of attachment to the upper rocker hinge, the more precisely the free belt end is pulled along in the course of adjustments to the height adjustment device, and also, the more strongly subject to loads the rear rocker and the remaining parts in the event of an accident will be. The position specified above comprises an especially advantageous solution.
In yet another preferred embodiment, the rocker on the vehicle exterior side is bent towards the center line of the vehicle in such a way that the upper rocker hinge is distinctly nearer to the center line of the vehicle than the lower rocker hinge. In this case, the difference amounts to several centimeters, e.g. 2 to 5 cm. In this manner it is possible that the runner pair on the vehicle exterior side be placed laterally so far outside that it is actually no longer to be found directly beneath the car seat. This results in more leg room. This also allows a more advantageous course for the lap belt. Furthermore, the runner pair on the vehicle exterior side is mounted to the area of the underbody structure where higher stability is available.
The conjoint middle piece of the safety belt, at which, in the event of an accident, even higher traction generally occurs than at the so far considered free end of the lap belt, can be directly caught up by the seat runner. In this case there is the added advantageous suggestion of mounting the belt catch directly on the seat runner of the runner pair found at the center line of the vehicle. In particular, a mounting in the form of an L-shaped angle presents itself in this connection. One leg of this angular mounting is joined to the seat runner. Onto the other leg, the belt catch is placed. In this embodiment, it is essentially only the runner pair and the L-shaped angle which are subjected to the stress of the forces of acceleration occurring in an accident.
However, the belt catch can also be attached to the rocker at the center line of the vehicle. This has the advantage, depending on the position of the belt catch along this rocker hinge, of the belt catch more or less following the movement of the seat base in the course of a height adjustment. The configuration of the belt catch in an upper area of the rocker
Becker Burckhard
Beneker Wilfried
Frohnhaus Ernst-Reiner
C. Rob. Hammerstein GmbH & Co KG
Cranmer Laurie K.
John Lezdey & Assoc
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