Patent ID: 7467480
Filing Date: 2008-12-23
Classification: G01B

Abstract:
1. A digital displacement measuring instrument, comprising: a body; a spindle screwed into the body to be axially advanced and retracted relative to the body; and an encoder that detects a displacement of the spindle, the encoder including a rotor rotating in a circumferential direction of the spindle and a stator spaced apart from the rotor by a predetermined gap and fixed onto the body, the rotor being supported by a rotation transmitter having an engaging portion to be engaged with an engaging groove provided on an outer circumference of the spindle in the axial direction while keeping a constant gap against the stator, wherein the rotation transmitter has a rotor support member for supporting the rotor, a rotary piece having the engaging portion to be engaged with the engaging groove and a biasing unit provided between the rotary piece and the rotor support member, the rotary piece is supported by the rotor support member in a manner circumferentially rotatable around a rotation shaft provided parallel to the axis of the spindle, and the biasing unit biases the engaging portion onto the engaging groove via the rotary piece.