Material handling apparatus

Abstract

An improved material handling apparatus includes a base boom section which is rotatably supported in a cradle and a second boom section which is telescopically received within the base boom section and is movable axially relative to the base boom section. A force transmitting assembly is provided to transmit rotational drive forces from a tilt motor to the base boom section to effect rotational movement of the two boom sections about their longitudinal axes. This force transmitting assembly also retains the base boom section against axial and radial movement relative to the cradle. The force transmitting assembly includes a single force transmitting member or body which is fixedly connected at one end portion to an end wall of the base boom section and is rotatably supported by a cradle mounted thrust bearing assembly. The thrust bearing assembly holds the single force transmitting member against axial movement to thereby retain the base boom section against axial movement. A gear segment on the force transmitting member cooperates with a gear connected to the tilt motor which is disposed between an end wall of the base boom section and the cradle. Upon operation of the tilt motor, the force transmitting member rotates the two boom sections relative to the cradle. The force transmitting member is provided with fluid passages and manifold rings which conduct fluid to effect operation of another motor to extend and retract the two boom sections.