Deere + Company

Marlin Martin Onnen

Marcus Bitter

Ralph Edwin Shirley

Mark Desmond Fallon

David Price

David Allen Larson

Steffen Schlemmer

A hydraulic control circuit for a hydraulic cylinder is described for the raising and lowering of a boom on a telescopic loader. First and second chambers of the hydraulic cylinder are connected to a control valve over first and second supply lines and are selectively connected to either a hydraulic pressure source or to a hydraulic reservoir. The circuit includes on-off valves for controlling the flow through a first hydraulic line extending between the first chamber of the cylinder and the hydraulic reservoir, and through a second hydraulic line extending between the second chamber and the hydraulic reservoir in such a way that a floating position can be provided. Furthermore, a load-holding valve arrangement is provided in the first supply line at a location between the control valve and the first chamber of the cylinder. To provide assurance against uncontrolled lowering of the boom during switching to the floating position under load, a valve arrangement is provided that controls the flow rate as a function of the flow rate.

Hydraulic control circuit for a hydraulic lifting cylinder

A vehicle steering mode selection control system includes an operator controlled push-to-turn switch steering mode select device, and a control circuit operatively connected to the mode select device, to steering mode actuators, to steering mode indicators and to wheel alignment indicators. The control circuit includes a timer which is actuated for a certain time period in response to pushing of the push-to-turn switch. A lamp control module is connected to the timer and permits illumination of the wheel alignment indicator lamps only during this time period. A relay is connected between the push-to-turn switch and the timer to prevent the lamp control module from responding during the time period to further pushing of the steering mode select device.

Vehicle steering mode selection control

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Crystal Lake, IL, United States of America

Marlin Martin Onnen