Caterpillar Inc.

Robin S Arndt

Daniel T Mather

Ricky D Vance

Andrew O Fonkalsrud

Steven R Wells

Michael G Seil

John T Nebgen

Charles E Rector

A parking brake switch for a vehicle including a switch having a contacting surface, the switch being positioned between an actuated state and a deactuated state, a first contact connected to a brake valve associated with an electro-hydraulic braking system, a second contact connected to a pair of electronic control modules, and a third contact connected to the pair of electronic control modules and a coil, the contacting surface being adapted to engage all of the contacts when the switch is in the actuated state.

Parking brake switch for an electro-hydraulic brake system

A remotely controlled brake system is provided to permit braking control of a machine from a remote location while still permitting an operator located on the machine to control the braking function of the machine. Remote control is accomplished by providing a source of pressurized fluid on the machine with an electrically controlled proportional valve arrangement that is responsive to a remote signal to direct pressurized fluid to the brakes of the machine in parallel with the pressure control being directed to the machine brakes by an operator input mechanism.

Remotely controlled brake system

A pilot stage of an electrohydraulic control valve controls the position of a pilot actuated main stage by controlling fluid flow through a flow path that connects a supply port to an exhaust port and to an end of the main stage. A proportional valve of the pilot stage has a valve element for establishing a variable flow control orifice to control fluid flow through the flow path and a bleed orifice disposed in the flow path downstream of the proportional valve to generate fluid pressure upstream of the bleed orifice and at the end of the main stage.

Pilot stage of an electrohydraulic control valve

A hydraulic cylinder snubbing arrangement includes a pilot operated control valve having a predetermined snubbing position at which flow exhausted from a hydraulic cylinder actuating chamber must pass through a plurality of flow restricting orifices in a valve spool when the hydraulic cylinder is retracted to a predetermined position. The valve spool is shifted to the snubbing position automatically by reducing the fluid pressure in a pilot chamber at the end of the valve spool to a predetermined level so that a snubber spring device resiliently moves the spool from a lower or float position. By forcing the fluid to pass through the restricted flow path created by the orifices, the gravity induced velocity of the hydraulic cylinder is greatly reduced as the hydraulic cylinder approaches its end of stroke position.

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Joliet, IL, United States of America

Robin S Arndt