Finger pressure actuable dump control system for dump vehicles

Abstract

A pushbutton control system for raising and lowering the dump body of a dump vehicle. Included are 'up', 'hold' and 'down/float' switches which are connected in circuit with 'up', 'down' and 'float' solenoid valves. These valves on energization direct pressurized air into the 'up', 'down' and 'float' chambers of two air cylinders included in an actuating mechanism for a hoist valve controlling the telescopic hoist cylinders of the vehicle. The dump body is raised upon depression of the 'up' switch with the consequent opening of the 'up' valve. The depression of the 'down/float' switch, resulting in the opening of the 'down' valve, causes the dump body to lower by the forced contraction of the hoist cylinders. Upon subsequent release of the 'down/float' switch the 'float' valve opens to allow the dump body to lower under its own weight. The depression of the 'hold' switch, with the consequent closure of all the solenoid valves, makes it possible to hold the dump body against movement in any desired position. Pilot lamps are provided to indicate the operating conditions of the control system in response to the actuation of the switches.