Sensor with a lateral retaining arm

Claim 1

A sensor assembly including a measuring head having a measuring surface for sensing the movement of an object, a lateral retaining arm extending laterally from said measuring head, said lateral retaining arm having a guide bore extending substantially perpendicular to a plane containing said measuring surface, a carrier member slideably received in said guide bore and having a size so that said retaining arm can rotate about said carrier member, said carrier member being formed with a central bore, a fastening bolt received in said central bore for fixing said retaining arm and said measuring head on a base member having a surface extending in a plane substantially parallel to said measuring surface, said carrier member terminating in an end surface located inside said guide bore, an expandable ring-shaped clamping member located on said end surface of said carrier member, the external diameter of said clamping member being of a size so as to fit inside said guide bore, said fastening bolt being formed with a cone-like enlargement located adjacent the ring-shaped clamping member so that when said fastening bolt is tightened on the base member said cone-like enlargement urges said clamping member against the end surface of said carrier member and expands said clamping member radially outwardly against the guide bore.