Abstract: Inching valves for providing controlled slow movement of a vehicle normally have a valve mechanism therein to control the pressure level of the fluid being directed to the driving clutch of the vehicle. Upon release of the pedal, a sudden jerk of the vehicle may occur. The modulating inching valve of the subject arrangement provides a housing having a valving mechanism slidably disposed therein and operative to selectively block communication between an inlet port and an outlet port. The modulating inching valve further includes an input actuator mechanism operative to selectively control the valve mechanism in response to the position of the operator's inching pedal. Through a portion of a predetermined travel distance of the input mechanism the operator controls the rate of pressure being supplied to the fluid actuated device and during the remaining portion of the predetermined travel distance the modulating relief valve automatically controls the rate of pressure rise.

Abstract: A circuitous path flow restrictor (10) having no moving parts includes a fluid director member (16) having a core (24) and a plurality of fins (26) extending from the core and defining alternately axially offset notches (50,52). The fluid director member is encircled by a containment member (54) such that a serpentine fluid flow path (58) is defined therebetween to provide a fluid flow resistance level equivalent to a simple orifice of much smaller diameter. The fluid director member can be made by a precision casting process for economy of manufacture.

Abstract: A transmission control system is provided for use with a transmission assembly having a torque converter which couples a power input member with a transmission speed ratio section. A lock-up clutch is provided to selectively bypass the torque converter and couple the input member directly with the transmission speed ratio section. Some systems provide converter lock-up and lower transmission control pressure resposive to positioning of the transmission speed selector valve while others require additional complicated controls to operate the lock-up clutch of the converter and reduce transmission control pressure relative to the vacuum level of the prime mover.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A crawler tractor vehicle having fluid actuated steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. The vehicle further includes a transmission operable upon supply of fluid pressure thereto and a priority valve for providing that a certain level of fluid pressure is supplied to the brake system to provide a disengagement thereof prior to fluid pressure being supplied to the transmission.

Abstract: A selector valve selectively communicates pressurized fluid from an inlet to an outlet and is adapted to be connected to a clutch of a transmission. The selector valve comprises a spool normally blocking communication between the inlet and outlet, a selector piston responsive to a control signal for movement towards the spool and a load piston reciprocally mounted in the selector piston and adapted to be moved thereby to control movements of the spool. A modulating orifice is interconnected between the outlet and the load piston to control movements of the spool for modulating fluid pressure in the outlet to a predetermined level.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A crawler tractor vehicle having steering clutches and associated steering brake includes a control apparatus for each clutch and brake system, including a valve made up of a valve body, and a clutch valving spool and a brake valving spool movably associated therewith. In one embodiment, the clutch valving spool and brake valving spool are identical in configuration, and are disposed in a common bore. Actuator means are associated with such clutch valving spool and brake valving spool, in one embodiment including an actuator assembly made up of a plurality of plungers movable relative to each other and relative to the valve body to provide particular movement of the clutch and brake valving spools. In another embodiment, the actuator means comprise mechanical linkage means, for providing movement of brake and clutch valving spools positioned in respective separate bores defined by the valve body.

Abstract: A towing winch system with fluid pressure actuated power input and winch input clutches disposed serially between the power take-off and cable drum. A controlled but variable reduced fluid pressure from a source is applied to the winch input clutches and full fluid pressure is applied to the power input clutch through a valve which opens in response to and when the pressure applied to the winch input clutches exceeds a manually selectable low or high value for inching or non-inching operation, respectively.

Abstract: A control valve pressurizes an outlet conduit when a variable fluid pressure signal rises above a first predetermined level and depressurizes the outlet conduit when the variable signal subsequently drops below a second level that is lower than the first level, the valve further functioning to maintain the outlet conduit unpressurized without regard to the variable fluid pressure signal level in the absence of a second fluid pressure signal. The control valve automatically controls a fluid pressure operated lock-up clutch of a torque converter in a vehicle transmission system. The variable fluid pressure signal source may be a governor producing a pressure proportional to vehicle speed while the second fluid pressure signal source is one or more of the transmission drive conditioning devices.