Patent ID: 6352139
Filing Date: 2002-03-05
Classification: F16D

Abstract:
A locking device for accurately locking an indexable, rotatable spindle to a desired rotational angle, comprising:a brake disc fixed to the spindle; a non-rotatable frame surrounding the brake disc; an upper disc having a first portion fixed to the frame opposite to an upper surface of the brake disc, wherein said first portion is non-movable relative to the frame; a upper brake member through which the spindle passes, the upper brake member being movable in the axial direction of the spindle between an unlock position and a lock position, the lock position being closer to the brake disc than the unlock position; a lower disc having a second portion fixed to the frame opposite a lower surface of the brake disc, wherein said second portion is non-movable relative to the frame; a lower brake member through which the spindle passes, the lower brake member being movable in the axial direction of the spindle between an unlock position and a lock position, the lock position being closer to the brake disc than the unlock position; drive means for moving the upper and lower brake members in the axial direction of the spindle; wherein the upper and lower brake members press the upper and lower discs against the brake disc when the upper and lower brake members are at their lock positions, and the upper and lower discs oppose the upper and lower surfaces of the brake disc across respective gaps when the upper and lower brake members are at their unlock positions.