| 摘要 |
<p>1. A dental treatment chair, on whose back rest (1) a head support (2) is mounted by means of a supporting element (3) and is displaceable along the longitudinal axis of the back rest and is rotatable about a horizontal transverse axis (18) between different positions of inclination by means of an adjusting device which is arranged in the casing (6) of the head support, which head support can be locked in said positions and unlocked by means of a manually operated releasing element (20) characterised in that the adjusting device comprises an electric motor (9) which can be switched on and off by means of the releasing element (20) and includes a spindle (7) which is arranged in the casing (6) of the head support in the longitudinal direction thereof and driven by the motor (9), and a spindle nut (10) which engages with said spindle and upon which a rocker arm (12), which is arranged transversely to the longitudinal direction of the casing (6) of the head support, acts, which rocker arm (12) is pivotably mounted (13) on the side of the casing (6) of the head support opposite the spindle (7), and that there is arranged a push/pull rod (15) which is articulated firstly to the rocker arm (12) so as to be adjacent to the swivel bearing (13) and secondly to an attachment (16) to the supporting element (3) at a distance (a) from the transverse axis (18) to form a moment arm (a).</p> |
