Assist assembly for cab structure

Abstract

An assist assembly for reducing the work required by an operator in rotating a cab structure on a machine between selected positions. The basic components of the assist assembly include a bellcrank member, a cab movement transmission linkage, and an extensible and retractable actuator. The actuator applies a constant pushing force on the bellcrank member urging it to rotate in a first direction. This pushing force is converted by the bellcrank member into a pulling force on the cab movement transmission linkage which assists the operator in rotating the cab structure until the center of gravity of the cab structure moves to a point directly above its rotational axis on the machine. When the center of gravity for the cab structure moves past direct vertical alignment with its rotational axis, the pulling force on the transmission linkage is opposed and counteracted by an even greater opposite force from the cab structure which urges the bellcrank member to rotate in an opposite direction causing the actuator to retract under pressure. Thus, the bellcrank member reverses the direction of stroke of the actuator when the center of gravity for the cab structure moves in either direction beyond direct vertical alignment with its rotational axis. This assists the operator in rotating the weight of the cab structure up to the point of vertical alignment and then dampens or retards the movement of the cab structure until it reaches a stop position.