Abstract: A transmission control system for actuating a hydraulically controlled vehicle transmission that includes a pair of shiftable valve members determining four range speed conditions and two shiftable valve members determining whether the vehicle is in forward or reverse. Operating in conjunction with the speed range valve members is a fill control system which provides for rapid filling of the clutches and a pressure control system which provides for the controlled rate of energization of the clutches once the clutches have been filled to eliminate shift shock.

Abstract: A control system for the boom and bucket operation system on a front end loader that includes an unloader valve responsive to pilot valve pressure to bypass hydraulic fluid pumped by an auxiliary pump to the reservoir while maintaining the primary pump supply to a loader valve which supplies pressure to the boom and bucket cylinders in response to the operation of pilot valves. The unloader valve bypasses the auxiliary pump flow when the pressure is below a predetermined value and when the pressure is above a second higher predetermined value.

Abstract: A pulsation limiter for a manually actuated hydraulic valve includes a spring biased, motion retarding plunger in an auxiliary bore within the valve housing and having a helical groove disposed on its periphery abuts against the input sleeve during the initial portion of its travel to actuate the brakes, a check valve in the plunger allowing filling of the expanding cavity in the auxiliary bore behind the motion retarding plunger. When the brake pedal is released partially or completely, the input sleeve moves until it abuts against the plunger. Thereafter, the pressure buildup in the auxiliary bore cavity closes the check valve in the plunger and the input sleeve can only move relatively slowly back to its initial position as the fluid trapped in the auxiliary bore cavity exits through the helical groove.

Abstract: Master clutch pressure and lubrication valve which consolidates both such functions or services for a power operated clutch pack, all to insure the necessary conservation of cooling lubrication oil at times when full engagement pressure on the clutch pack can have stabilized it against further clutch slip, but at times otherwise to insure a liberal flow of the cooling oil. By built-in delay of cooling flow change following clutch actuation in the valve, it makes the transition between the two rates of cooling flow by temporarily sustaining liberal circulation of the cooling flow for that initial time after full engagement pressure exerts itself on the clutch pack. Sometimes a clutch will continue slipping, just for that initial time.

Abstract: The present invention is a stabilizer for steering priority flow divider valves. The present invention prevents the variable displacement pump of the steering hydraulic system from destroking to zero displacement when the steering hydraulic demand rapidly varies from a high level to a low level of demand. The use of the present invention is especially advantageous in hydraulic systems which are close centered with pressure and flow compensation.

Abstract: Clutch-clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically, one of the clutch cylinders and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the one clutch, to apply the one clutch and release the brake or, by proper modulation, to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: A pilot valve having a universally tiltable joy stick further includes a cam attached to said joy stick and movable therewith. A plunger is selectively movable into engagement with the cam for latching the joy stick in a selected one position. Fluid is supplied to the plunger for developing a force acting thereon to move the plunger into engagement with the cam. The fluid force is eliminated and the plunger disengaged from the cam to delatch the joy stick.

Abstract: A pulsation limiter for a manually actuated hydraulic valve includes a spring biased, motion retarding plunger in an auxiliary bore within the valve housing and having a helical groove disposed on its periphery abuts against the input sleeve during the initial portion of its travel to actuate the brakes, a check valve in the plunger allowing filling of the expanding cavity in the auxiliary bore behind the motion retarding plunger. When the brake pedal is released partially or completely, the input sleeve moves until it abuts against the plunger. Thereafter, the pressure buildup in the auxiliary bore cavity closes the check valve in the plunger and the input sleeve can only move relatively slowly back to its initial position as the fluid trapped in the auxiliary bore cavity exits through the helical groove.

Abstract: Clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically a clutch cylinder and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the clutch, to apply the clutch and release the brake, or by proper modulation to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: Clutch-clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically, one of the clutch cylinders and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the one clutch, to apply the one clutch and release the brake or, by proper modulation, to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: Clutch-clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically, one of the clutch cylinders and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the one clutch, to apply the one clutch and release the brake or, by proper modulation, to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: Clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically a clutch cylinder and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the clutch, to apply the clutch and release the brake, or by proper modulation to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: A multi-functioning hydraulic transmission control circuit in which a shifting power is provided by hydraulic pressure.

Abstract: Clutch-clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically, one of the clutch cylinders and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the one clutch, to apply the one clutch and release the brake or, by proper modulation, to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: A multi functioning hydraulic transmission control circuit including interacting valve mechanism parts which, in response to a shift being called for in a clutch-cylinder-controlled multi-speed transmission, inaugurate a fill pressure flow to the clutch cylinders concerned, prior to the subsequent fluid pressure rise effected therein; thereafter, upon completion of the fill, the parts modulate pressure rise of the hydraulic clutch fluid from and at approximately actual clutch fill pressure up to, and remaining at, the final pressure of engagement.

Abstract: Clutch-brake steering unit having hydraulically actuated cylinders which are adapted for controlling same to control rotation of a track-drive sprocket in a crawler tractor, and which are under control of a clutch-brake steering valve mechanism. A bore in the valve is common to and receives both an independently slidable hydropotentiometer spool precisely providing a master setting pressure, and an independently slidable metering spool providing a single pressure signal always hydraulically matched with the precise master setting pressure. A clutch cylinder and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that the generated single pressure signal when applied to the inlet-outlet port alternately operates the cylinders to apply the brake and release the clutch, or to release the brake and apply the clutch, or by proper modulation to partially engage either, i.e.

Abstract: Booster providing both hydraulic feed-back and hydraulic feel-back in a two-stage operation in which we boost-brake a vehicle. Concentric, nesting, inner and outer control parts include, as the sliding outer part, a brake-pedal-connected input signal spool or sleeve for developing a desired signal pressure varying linearly along the length of, and therefore according to the sliding position of, the sleeve; the inner part constitutes a captive, telescoping metering spool with its ends in corresponding ends of the spool sleeve.

Abstract: A control for a spring-apply, pressure release brake system having a pilot signal-generating valve and a slave brake valve interconnected by a pilot signal line. Hydraulic pressure is directed to both the pilot valve and the slave valve. Manual stroking of the pilot valve modulates the pressure to the signal line. A spool within the slave valve senses both the signal pressure and the brake pressure and moves to an equilibrium position to equalize the signal and brake pressures.

Abstract: A multi-functioning hydraulic transmission control circuit including interacting valve mechanism parts which, in response to a shift being called for in a clutch-cylinder-controlled multi-speed transmission, inaugurate a fill pressure flow to the clutch cylinders concerned, prior to the subsequent fluid pressure rise effected therein; thereafter, upon completion of the fill, the parts modulate pressure rise of the hydraulic clutch fluid from and at approximately actual clutch fill pressure up to, and remaining at, the final pressure of engagement.

Abstract: Clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically a clutch cylinder and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the clutch, to apply the clutch and release the brake, or by proper modulation to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.