This invention relates to a device for longitudinally adjusting vehicle seats.
It is known that the front seats of modem vehicles are provided with means for longitudinally adjusting their position. For this purpose a pair of parallel guides is fixed on the vehicle floor to each seat to act as a support and guide for a corresponding pair of mobile guides rigid with the seat.
These adjustment systems also usually comprise slider means such as rollers and sliding blocks interposed between the fixed guides and mobile guides to facilitate movement of the seat, and locking means for locking the fixed guides and mobile guides together when adjustment has been effected.
In some current devices the movement of the mobile guides is halted by the use of a safety mechanism. This mechanism normally consists of a toothed latch fixed to the mobile guide and urged upwards by a spring so that it engages in corresponding toothing on the fixed guide, to lock the seat in position.
The release is achieved manually by operating a tubular handle pivoted on both the right and left mobile guide. To overcome the resistance offered by the spring which urges the latch, the latter is released from the toothing on the fixed guide to enable the seat to move longitudinally.
An object of the present invention is to provide a simplified seat locking device which enables the latch component to be dispensed of, by making the spring multi-functional in the sense that by being suitably sized, shaped and fixed, it is able to lock the guides together.
A further object of the invention is to provide a device of simple and reliable construction and of low cost.
The fixing systems used up to the present time for securely fixing the glides to the seat or to the vehicle floor usually require the guides to have hexagonal nuts or bolts welded to them.
The assembly of the guides therefore has to be preceded by the welding of the nuts. This welding is a drawback in cost terms, and is avoided by using the device according to the invention.
A further object of the invention is to provide a mobile guide, the section of which incorporates a series of threaded collars for seat/guide fixing, as a replacement for the traditional hexagonal nuts.
In order to reduce lateral slack during the longitudinal movement of the seat, the present invention provides a new guide and roller configuration, in which these components have a self-centering profile.
A further object of the invention is to propose a device for longitudinally adjusting motor vehicle seats able to lock the right and left guides independently, and to simultaneously release them.