Abstract: The head support unit may be attached by attachment means (13) to a chair, e.g. a wheel chair. A set screw (15) permits vertical adjustment. The head rest (19) may be horizontally moved by the user into the desired position. This movement takes place without a recognizable movement in vertical direction. The head rest (19) is carried by a slender lever parallelogram (18) which is operatively connected by a flexible Bowden-cable (21) to the motor (23) located at a distance on the chair. This flexible connection (21) permits not only to put the motor (23) at a suitable location away from the head of the user, but does also not hinder a vertical adjustment of the head rest (19) by means of the vertical support bar (11) and the set screw (15).

Abstract: The chair according to the invention comprises a chassis (60) with a support for the user, specifically a seat, a cab for a stroller, or handles for pushing the device. The chassis consists of two portions (61, 62) connected by an articulation (63) with a transverse axle. The first chassis portion (61) is equipped with two main wheels (66) whose common axle (67) is near the line of action (p) of the user's weight, and at least one front or rear contact wheel (68). The second chassis portion (62) uses at least one contact wheel (69) to contact the ground at the other end of the chair. The wheels may be arranged in a diamond shape, and the contact wheels (68, 69) turn freely. There is preferably a spring device (72) connecting the two chassis portions to store and release energy when clearing obstacles. In the case of a wheelchair, the main wheels (66) are either manually driven or controlled by separate motors. The distinctive features of such a device are ease of manipulation and ability to clear obstacles.