Forward-reverse and brake inching control

Claim 1

Control apparatus for a vehicle having a transmission with fluid-actuated clutch means and hydraulic brake means for arresting movement of the vehicle, comprising a source of fluid pressure including fluid-pressurizing means therefor; a fluid pressure conduit connecting said pressure source with said clutch means; coNtrol valve means disposed in said conduit, said control valve means including a housing provided with a pair of cylindrical bores located parallel to each other, a pair of spool valves axially slidably engaged respectively within said bores, said housing having ports communicating with said conduit, means on said spool valves defining respective pressure chambers at times in communication with said conduit through said ports and located to selectively control passage of pressure fluid through said conduit responsive to movement of said spool valves, whereby to activate and de-activate said clutch means, a pair of inching pistons slidably disposed within said bores, respective forcetransmitting resilient members interposed between said inching pistons and said spool valves, means interconnecting said brake means with said inching pistons, a pair of respective shift rods slidably engaged in said bores, further force-transmitting resilient members interposed between said shift rods and said spool valves, and a shift lever connected to said shift rods for selectively operating said rods so that selected operation of said shift rods by said shift lever selectively moves said spool valves and so that a selected spool valve controls fluid pressure in the conduit in accordance with the fluid pressure value in its associated pressure chamber, whereby said spool valves are operated by said inching pistons and first-named resilient members when the brake means is operated to arrest the vehicle, whereby to provide inching effects.