Uniaxial wirkendes Klemmkörpergesperre

摘要

The invention relates to a head rest (35) for a vehicle seat, the height of which can be adjusted in relation to a back rest (36) of the vehicle seat. To this end, the head seat (35) is fixed to support rods (37, 38), the length of which can be adjusted in a stationary opening (40) in the back rest (36). A clamping element (10) locks the head rest (35) in a given position in relation to the opening. In order to prevent the support rods (37 and 38) from sinking during an accident, the invention provides that the blocking element (10) be designed as a free wheel unit (22, 16, 26) running in a linear direction of movement, which prevents at least one of the support rods (38) from being pushed down into the opening (38) when the blocked position is engaged. The blocking element can be locked and unlocked by means of an operating device.