SHAFT SHIFTER APPARATUS HAVING CATERPILLAR GROOVE

摘要

PURPOSE: A shaft shifting apparatus with a caterpillar groove is provided to reduce cost for electric devices and accidents due to electric devices by rectilinear reciprocation of a moving block in a regular cycle without electric devices to rotate a motor to forward and reverse directions. CONSTITUTION: A first thread groove(32) is formed to an outer peripheral surface of a screw shaft(12) from a front end to a rear end to move a moving block(25) forward when the screw shaft is rotated in one way. A second thread groove(34) is formed to be connected to an end of the first thread groove from the rear end to the front end of the screw shaft to move the moving block. Therefore, first and second thread grooves are formed to be an endless track. The moving block has a center ball(50a) rotated in a specific site and guide balls(50b,50c) rotated in guide grooves(53a,53b) of a hub. The hub is formed to front and rear portions of the center ball to a longitudinal direction of the shaft. Therein, the moving block moves along the screw shaft when the screw shaft is rotated.