Slide cam assembly for railroad-crossing gate mechanism

摘要

A motor controller for use in railway-crossing signal-gate mechanisms is provided herein. The controller is of a cam type which includes a cam assembly having a movable cam insert that cooperates with a cam follower and switch assembly. The switch controls the gate arm raising motor. The cam insert and cam follower are arranged such that when the gate arm approaches the upright position the cam insert slides quickly or snaps to a position, which permits the switch contacts to open quickly, thereby minimizing arcing between the switch contacts. Moreover, with the cam insert in this position, oscillation of the gate arm about the upright position, which is caused by the gate arm striking the arm stops and bouncing back, is minimized.