GB949878A - Improvements in or relating to a vehicle having fluid-operable equipment - Google Patents

Abstract

949,878. Power take off; vehicle control. DENNIS BROS. Ltd. Aug. 27, 1962 [May 27, 1961], No. 19216/61. Heading B7H. An hydraulic circuit for auxiliary equipment on a motor vehicle supplied by an enginedriven pump is isolated when the engine r.p.m. reach a predetermined value. The hydraulic circuit may include rams for operating loading and tipping equipment of a refuse-collecting vehicle. As shown, an extension 3, Fig. 2, of the vehicle gear-box is provided with a power take-off shaft 2 and a drive to an electric generator 8, the drive to the power take-off shaft being controlled by a lever 4 which is only engageable when the vehicle is operated below a certain engine speed. A pump 7 is driven from the shaft 2 through a shaft 5 and coupling 6 and has an output line 11 leading via a pipe 12 and relief valve 15 to a selector valve 14 operated through a rod 25 and having ports 28 and 29 leading to loading equipment through pipe 31 and lifting rams 33 through pipe 32, respectively, and an exhaust port 27 leading through pipes 30 and 16 to reservoir, the pipe 16 also being connected to relief valve 15. A solenoid operated valve 18 is connected through a port 19 and pipe 17 to the relief valve 15 and through a port 20 and pipe 21 to the reservoir. The ports 19 and 20 are closed when the solenoid is de-energized, and are connected together when the solenoid is energized, whereby the output from the pump is returned to reservoir. The generator 8 is connected through a control unit 35 to a relay 36, the contact of which is normally open and is in series with the solenoid 22 of valve 18 and with the vehicle ignition switch 38 and battery 37. The generator 8 produces a predetermined voltage at a predetermined r.p.m., at which speed the relay 36 is energized to complete the circuit through the solenoid 22 whereby valve 18 is operated. The circuit also includes a switch 40 which is coupled by a spring 43 to the clutch rod 41, whereby when the clutch is depressed, the output of the pump is again returned to reservoir by actuation of the valve 18. The control box 35 regulates the voltage output from the generator. The control lever 4 for the power take-off shaft 2 is connected through a lever 47 and cable 45 to a stop member 45, which, when the shaft drive is engaged, obtrudes the path of a plunger 49 connected to the accelerator pedal limiting its movement.