Anti-runaway apparatus and method for a power-and-free conveyor system

Abstract

Apparatus for preventing runaway of trolleys in a power-and-free conveyor system that includes a friction bar that extends lengthwise of the free conveyor track on a side of the track remote from the power conveyor for motion lengthwise of the track at an acute angle to the direction of motion of the trolleys along the track. The friction bar is releasably biased laterally outwardly from the track and in a direction lengthwise of the track opposed to the direction of trolley motion on the track so that trolleys may travel freely along the free conveyor track past the bar. In the event that a trolley is traveling at excessive velocity along the tree conveyor track, the friction bar is moved in the direction of motion of the trolley and at the acute angle laterally into a position for frictional engagement with the trolley on the track, such that momentum of the trolley cooperates with frictional engagement of the bar with the trolley to wedge the bar against the trolley and arrest motion of the trolley on the track. Thus, momentum of the trolley along the track cooperates with angulated motion of the bar into frictional engagement with the trolley for automatically and inherently increasing frictional forces that arrest motion of the trolley on the track.