CPC A61G 15/125 (2013.01) [A61G 2200/16 (2013.01)] | 12 Claims |
1. A treatment chair comprising a headrest, connected to the chair with a headrest arm, and a position adjustment member for the headrest, characterized in that the position adjustment member comprises at least one ratchet mechanism with pawls to lock the headrest in a wanted position,
wherein the pawls are arranged to block the rotation of a ratchet element of the at least one ratchet mechanism to one direction and to allow the rotation of the ratchet element to another direction,
wherein the ratchet mechanism comprises more than one pawl to form a group of parallel pawls and the ratchet element is a cylindrical ratchet element defining an axis of rotation and being operatively coupled to the more than one pawl, the cylindrical ratchet element comprising a group of recesses arranged at angular positions relative to each other about the axis of rotation for the more than one pawl to stop and lock the rotation of the cylindrical ratchet element in a first direction of rotation of the cylindrical ratchet element,
wherein recesses of the group of recesses are arranged in rows one after the other on the cylindrical ratchet element, and all the recesses in the same row are in the same plane at an outer surface of the cylindrical ratchet element, and
wherein row of the recesses is adjacent another of the rows, and in each row of the recesses the angular position of the recesses on the cylindrical ratchet element is different from the angular position of the recesses of the other rows.
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