Abstract: A brush wear indicator includes a first contactor and a second contractor movable relative to the first contactor from an open position to a closed position to connect an electrical circuit to an indicator. The second contactor is maintained in the open position against the resiliency of a leaf spring by a coil spring which urges a brush toward a commutator in response to wear to the brush. When the brush wears away to a preselected length the coil spring will have moved to a position at which the leaf spring is free to bias the second contactor to the closed position.

Abstract: A hydraulic circuit including a single pump and a plurality of control valves for communicating actuating fluid to the separate hydraulic motors from the single pump includes a synchronizing unit for initiating and terminating operation of the pump in response to operation of any of the control valves, the synchronizing unit including a pivotable gang plate adjustably mounting cam shoes separately associated with synchronizing levers connected to actuating elements for each of the control valves, the single gang plate thus being movable in response to operation of any one of the valves in order to initiate or terminate operation of the pump in closely synchronized relation to positioning of any one of the control valves to communicate the pump with one of the motors.