Control system for adjustable head restraint on automotive seat

In a system for vertical adjustment of a head restraint on an automotive seat, the system including support members/which support thereon the head restraint and are movable upwards and downwards, a reversible motor, means for transforming rotation of the reversible motor into a linear motion of a rigid bar, means for transmitting a linear motion of the rigid bar to the support members, a load-sensitive switch attached to the seat and a switching circuit for controlling the action of the reversible motor such that the head restraint is lifted from the lowest position thereof in response to the occupation of the seat by a passenger detected by the load-sensitive switch and is lowered in response to the withdrawal of the passenger from the seat, the switching circuit including a manually operated selector switch to enable manual control of the action of the reversible motor so as to move the head restraint from the automatically lifted position while the seat is occupied by a passenger,

• the improvement comprising a control device in said switching circuit to control the action of said reversible motor such that the head restraint is automatically lifted to an optionally predetermined position in response to the occupation of the seat by a passenger,
• said control device having a rotatable member formed of an electrically non-conductive material coupled with said reversible motor, a pair of conductors fixed to said rotatable member and a set of contacts stationarily arranged to individually make sliding contact with at least one of said conductors, said set of contacts including a fixed first contact whose angular position with respect to the axis of rotation of said rotatable member determines the lowest position of the head restraint, a fixed second contact whose angular position with respect to said axis of rotation determines the highest position the head restraint can take and a third contact whose angular position with respect to said axis of rotation and said first and second contacts is adjustable from the outside of said switching device and determines said optionally predetermined position of the head restraint.