Various demands are made on a modern seat. Earlier it was the comfort, and with it, the improvement in the handling, e.g., the side-support when cornering, that was decisive, nowadays, the highlights are, among other things, light coloured and definitely, hard-wearing, easy to maintain seating covers. In addition, there is the almost all-round electric adjustment, whose operation should not be a riddle for the user, the heating and ventilation, right up to the spinal support (lumbar support) and the ability to provide a massage while driving. All that's missing now, is the shock wave therapy.
With all these gimmicks, the safety-factor may, by no means, be neglected. Whereby, in the first place, the driver must be protected against diving (submarining) under the seat belt through a strong stabilisation of the seat front-edge (see figure 1). Side air-bags are usually accomodated into the back-rest which limits the using of protective covers. At least, for some time now, the locking device for the seat belt tongue is mounted onto the seat itself, so that, regardless of the seat position, it is always found at the same place. Sometimes, (e.g, in convertibles) the upper anchor-point with the roll-up is also integrated into the back-rest.
The above mentioned functions, although they place heavy demands on the drivers seat, do not apply to the drivers seat alone. In the rear seat version, to increase the transport volume, they should possibly also be removable. Thus, the various demands may come into conflict with the demand for lighter weight and less space-taking. How the latter problem is solved, can be seen in the seat frame. (figure 2 above) Here a servo-motor with flexible shafts on either side can be seen.The designers have even succeeded in maintaining space for the feet of the rear seat passengers. 05/10