Digital display micrometer

摘要

A digital micrometer (100) comprising a body (10), a spindle (2) slidably provided on the body and an encoder (40) that detects the displacement of the spindle. The encoder comprises a rotor (41) that rotates with the spindle and a stator (42) that is fixed on the body and spaced apart from the rotor by a predetermined gap. The rotor is supported by a rotor bushing (44) comprising an engaging key (43) cooperating with a groove (23) axially provided on the spindle. A rotor bushing restrictor (50) with a fixing member (51) connected to the body prevents the rotor bushing from moving away from the stator along the axial direction of the spindle. A rotor bushing attitude retainer (52) is placed between the rotor bushing and the fixing member. Two first abutment portions (522) of the rotor bushing attitude retainer contact the rotor bushing and two second abutment portions (523) of the rotor bushing attitude retainer contact the fixing element in order to keep the rotor bushing in a proper position without being inclined against the spindle. The two abutment portions of each pair are symmetrically placed to each other with respect to the axis of the spindle and the lines connecting the two abutment portions of each pair are orthogonal to each other.