Abstract: Switching arrangements, mechanical and electrical, for lowering or raising the vehicle body. They include electrically controlled discharge means for discharging hydraulic fluid from hydropneumatic suspension units, one for each wheel unit, a switch and electrically controlled valve means fluidly disposed in a fluid passage between a power chamber of an adjustable strut and a hydraulic fluid chamber of a gas cushion connected to the strut. Upon closing of the switch the valve will close the fluid passage to keep hydraulic fluid within the gas cushion and the discharge means will commence to discharge hydraulic fluid from the power chamber.

Abstract: Auxiliary control of fluid actuated steering apparatus for ships, boats and the like (hereinafter, "water vessels") includes isolating the existing steering control system from the steering apparatus and providing flow-communication between fluid under pressure and the steering apparatus through an auxiliary directional control sub-system enabling control of the steering apparatus independently of the main steering control system. According to a preferred embodiment, the source of the fluid includes a quantity of fluid stored under pressure and another quantity of fluid adapted to be provided under pressure. Isolation of the existing steering control system is carried out by coupling the source of fluid to a by-pass control sub-system preferably adapted both to isolate the main steering control system and to couple the auxiliary directional control sub-system to the steering apparatus.

Abstract: There is shown a safety control system for a self-propelled road roller having hydrostatic transmission, which includes a prime mover, an hydraulic pump driven by the prime mover and included in a main hydraulic circuit incorporating a motor with a power-off brake device, a check valve bridge with a ventable relief valve and a main control valve, and means for selecting automatically the speed and a predetermined operating speed, the speed selecting means comprise a secondary hydraulic circuit including means operatively connectible with the prime mover speed control means and controllable by the ventable relief valve in accordance with the operation of the main control valve.

Abstract: Three embodiments of a hydraulic safety mechanism are adapted to adjust the speed setting for an engine upon a reduction of pressure in a chamber, due for example, to loss of lubricating pressure, overspeeding of the engine or overheating, for example. In each embodiment, a speed control element for the engine is maintained in a normal operating position by a piston and cylinder combination which hydraulically blocks the chamber from the fluid drain in a normal operating position, the piston responding to reduced pressure in the chamber by communicating the chamber with the drain the piston thereby being hydraulically unlatched and permitting the speed control element to be repositioned to a reduced speed setting. A restrictive orifice, preferably of variable size and self-cleaning construction, regulates communication between the hydraulic circuit and the chamber. In another embodiment the safety mechanism includes a solenoid and accumulator chamber to adapt it for remote operation.

Abstract: A vehicle power steering system which effects steering with a pair of fluid actuated cylinders, one cylinder being operatively connected to each steerable wheel. Each cylinder is normally powered independently of the other cylinder so that both cylinders steer the vehicle. A pressurized fluid flow from a single source is divided for parallel flow along companion fluid flow paths to the individual cylinders. In response to a pre-determined pressure decrease sensed in one of those fluid flow paths a pressure responsive fluid diverter automatically diverts fluid flow from the reduced pressure flow path to the companion path so that all pressurized fluid in the system is then utilized to power one of the cylinders.

Abstract: To permit mechanical override of an electrical command system to control deflection of the swash plate or eccentricity of an axial or radial piston pump, for example upon failure of the electrical control system, a group of valves 5-8 are connected to an electrical control unit 23 and an additional control valve 4, 4' with a manual control lever 18', 30' is provided, the deflection of the swash plate 1 or eccenter ring 28 of the pump being sensed by a position transducer 22 moved by a linkage which includes the manual control lever. In normal operation, the manual control lever is maintained by spring pressure to deactivate the control valve but, under emergency conditions, the manual control lever will operate the first control valve 4, 4' to admit hydraulic control fluid to position the swash plate, or eccenter ring, respectively, the consequent movement of which is fed back through the linkage to the manual control lever.

Abstract: A hydrostatic winch having a hydraulic drive system with a dual control valve which adjusts pressure in control lines for varying the speed of lowering and hoisting a load and a brake for stopping the load has an overspeed control system which includes first valve means for relieving pressure in the control lines and first valve control means which opens the valve to automatically slow the speed of the winch when the load is moving too fast and a fail safe system for smoothly stopping the load, if necessary, which includes a braking system having a normally "off" brake which is biased towards an "on" position but which is held in the "off" position by a hydraulic cylinder.

Abstract: A differential drive arrangement interconnects positive displacement pumps with a manual actuating mechanism of an auxiliary fluid power steering system for vehicles to compensate for variations in fluid outflow from the pumps pressurizing two servomotors through two fluid operating circuits. Check valves in the two fluid circuits are arranged to maintain operation of only an appropriate one of the differentially driven pumps through one of the two fluid circuits when a pressure loss occurs in the other of the fluid circuits.

Abstract: A system particularly useful in trucks for manipulating a hydraulically operated work station comprising a network of four intercommunicating directional valves including a primary valve directing the flow to or from the work station and located between the work station, a hydraulic fluid pump and a fluid reservoir. The valve is designed so that when in the hold position fluid is continuously circulated from the reservoir through the pump and valve and movement of the work station is prohibited. The primary valve is normally biased to its hold position and is air actuated to its work or return position by an operational valve manipulated by a safety manual control. The operational valve directs air to the work or return side of the primary valve which is provided with free floating pistons for adjusting the primary valve spool in response to the flow of air in a surrounding chamber. The chambers and valve housing cooperate to fully seal the spool against contamination.

Abstract: A power transfer unit for transferring power between two separate hydraulic circuits comprising a casing, a pair of cylinder blocks in the casing, cylinders within each cylinder block, a piston in each cylinder, a leakage chamber within the casing, cam means located in said chamber for causing joint reciprocation of the pistons, pistons or extensions thereof extending from the cylinders to the cam means in the chamber, first valve means co-operating with the cylinders of the first block, second valve means co-operating with the cylinders of the second block, first leakage collecting means for the first valve means separate from said chamber, second leakage collecting means for the second valve means separate from said chamber, and a vent for said chamber separate from said leakage collecting means.By this arrangement any leakage to the chamber may be from either or both circuits and by virtue of the vent may be disposed of rather than fed back to either circuit.

Abstract: An automatic change-speed transmission for vehicles with a drive connection between a transmission output shaft adapted to be coupled with vehicle wheels and a secondary servo-force generator for the emergency supply of aggregates of the transmission control and shifting system operating with a servo-pressure, which drive connection is adapted to be disconnected by a disengaging mechanism, and with a permanent drive connection between a transmission input shaft adapted to be driven by a driving engine and a primary servo-force generator for the normal supply of the aggregates; a servo-motor for the disengaging mechanism which is adapted to be displaced into a disengaging position disconnecting the secondary servo-force generator from the transmission output shaft is brought into its working position by a control device operating in dependence on the servo-force of the primary servo-force generator when the actual value of the servo-force lies below a necessary operating value.

Abstract: Plural servo actuators are coupled to provide a redundant system for operating a common output device. Each servo actuator has plural servo valves each having one active output that causes controlled opposite operation of the output device and one passive output. A fault detector coupled to each servo actuator compares the sum of the passive output pressures with the pressures of two other fluid signals, in one case the supply and return fluid signals and in another case the two active output signals of the servo valves, to detect the condition thereof. A convenient checkout system and a fluid by-pass mechanism also are provided in the fault detector.

Abstract: A vehicle power steering system which effects steering with a pair of fluid actuated cylinders, one cylinder being operatively connected to each steerable wheel. Each cylinder is normally powered independently of the other cylinder so that both cylinders steer the vehicle. A pressurized fluid flow from a single source is divided for parallel flow along companion fluid flow paths to the indivdual cylinders. In response to a pre-determined pressure decrease sensed in one of those fluid flow paths a pressure responsive fluid diverter automatically diverts fluid flow from the reduced pressure flow path to the companion path so that all pressurized fluid in the system is then utilized to power one of the cylinders.

Abstract: A hydraulic valve actuator includes at least one piston mounted for reciprocating movement in a cylinder for bidirectionally rotating a valve shaft mounted in the housing. A resilient spring member is held in compression between one side of the piston and an end wall of the cylinder for yieldably urging the piston to rotate the shaft in one direction, in the absence of a sufficient opposing hydraulic pressure. A hydraulic pump driven by an electric motor selectively drives the piston against the force of the spring member for rotating the valve shaft in the opposite direction. An electric solenoid operated valve is connected with the cylinder at either side of the piston, to provide a selectively openable path for hydraulic fluid, by-passing the pump to relieve the pressure applied thereby.

Abstract: An electric control circuit for use in the ignition system of a vehicle having a vehicle battery powered auxiliary steering system which is energized upon engine failure or shutdown during vehicle operation. The ignition circuit disconnects the auxiliary steering system from the vehicle battery during heating of the pre-start intake air and during starting of the engine to eliminate unnecessary drain on the vehicle battery.

Abstract: A vehicle has elements providing a fluid pathway to the controlling system of spring actuated, normally locked brakes that are fluid releasable. The elements forming the fluid pathway are connectable to a fluid power assembly that is movable to and from the vehicle and releasably connected to the fluid pathway.

Abstract: A hydrostatic drive is disclosed in combination with a machine tool such as a sand core molding machine. A machine of this type comprises a fixed carriage and a core molding die mounted for rotation on the carriage. The drive includes a reversible fluid power motor having an output shaft. The motor output shaft is connected to a fail safe fluid power brake, and the brake shaft is, in turn, connected to a power transmission unit. When fluid power is applied to the brake and the motor, brake override means operate to release the brake to permit the motor shaft, brake shaft and tranmission to be turned by the motor and thereby operate the movable die.

Abstract: Control apparatus is provided for an apparatus which has first and second mechanisms. The control apparatus automatically, controllably energizes the second mechanism in response to a preselected condition of the first mechanism and selectively, controllably energizes the second mechanism independently of the condition of the first mechanism.

Abstract: A fluid power device such for example as one for opening and closing clam shell gates is operated by a ram under fluid pressure. A tank is provided for storing fluid under pressure and by a system of valving extension of the ram, as for a gate opening operation is inhibited until enough fluid under pressure is stored in the tank to assure completion of reverse operation of the ram to close the gates.

Abstract: A valve operator for steam turbine inlet control valves, each of the control valves being set by a corresponding valve cam. The operator comprises pilot operated hydraulic means for positioning the valve cams in a normal or power mode of operation, mechanical means for positioning the valve cams in a back-up or manual mode of operation and manual actuation means for actuating the hydraulic means in a normal mode of operation and, in the event of failure of the hydraulic means, for automatically actuating the mechanical means in a back-up mode of operation. The hydraulic actuator positions the valve cams through a rack and pinion assembly. Both the hydraulic means and the mechanical means are actuated from an input shaft driving a reduction gear box. The mechanical means comprises a dog connected to the output of the gear box and a pin on the cam shaft driven by the dog in the manual mode of operation.

Abstract: A device for regulating the operation of the transmission of a motor vehicle having a variator including a distributor which is influenced by a centrifugal regulator and/or resilient means which may be additionally controlled by an accelerator, for supplying pressure fluid from a source to a cylinder chamber or for connecting the chamber to a reservoir, a piston movable in said cylinder chamber being connected to a step-down control element of the variator. As a safety device to prevent imbalance in the event of a failure of the centrifugal regulator, a two-piston electrically operated valve is incorporated between said source and said chamber, the valve being controlled by an electrical circuit arranged to close the valve and prevent the flow of pressure fluid from the source to the chamber if the speed of the engine exceeds a predetermined value. If desired, the valve may serve to control flow of pressure fluid to and from a hydraulic brake for the input shaft of the variator.

Abstract: A control system for controlling the operation of a valve actuator. The system includes a control valve for conveying operating fluid to the actuator in response to an actuator control signal. A single conduit operably connected to the actuator control valve both supplies operating fluid to the control valve and conveys an actuator control signal to the control valve.

Abstract: A rotary shredder for waste materials has a pair of counterrotating cutting shafts, each of which mounts a series of spaced-apart disc-type cutters. The cutters on one shaft extend into the spaces between cutters on the other shaft so that the cutters on the two shafts coact to shred material fed therebetween. The two shafts are driven by a reversible radial piston hydraulic motor through a gear train arranged to rotate one cutter shaft at twice the speed of the other. The hydraulic motor is driven by an electric motor-driven fixed or variable displacement pump. A flow-reversing valve in the hydraulic motor control circuit controls the direction of fluid flow through the hydraulic motor. The reversing valve is electrically actuated automatically by a fluid pressure-operated switch to reverse flow and the direction of rotation of the cutters to prevent jamming whenever fluid pressure in the motor circuit rises to an abnormally high level.

Abstract: This invention discloses a brake system for use in automotive vehicles having Otto engines which includes a vacuum operated brake booster and a vacuum pump for generating the necessary vacuum for effective operation of the brake booster. A vacuum pump is positioned between and connected to the vacuum brake booster and the inlet manifold or carburetor induction pipe of an Otto engine. Means are provided for automatically switching the vacuum pump on if there is an insufficient amount of vacuum in the brake booster and also at the same time there is a predetermined amount of vacuum in the intake manifold.

Abstract: A hydraulic brake booster for use with an open center-type power steering system includes, upon the application of the vehicle brakes, a relief valve piston mechanism for setting the fluid pressure greater than the fluid pressure being previously circulated through the power steering system and a spool valve assembly for selectively admitting the high fluid pressure to a power piston device for the brakes, so that the load upon a pump, under non-application conditions of the brakes, will be reduced whereby it will be easy to accumulate the fluid pressure for the brakes in case of an emergency due to the fact that the fluid pressure set by the relief valve piston can be greater than the pressure required for charging gas within the accumulator.

Abstract: A control valve for a variable displacement pump or motor. The valve includes a pair of solenoids which are independently actuatable to port relatively high pressure fluid to their respective servo motor. A shuttle valve actuated by the high pressure fluid is used to simultaneously port the fluid from the other servo motor to a low pressure fluid source. A manual valving system is also provided having a pair of balls each biased into engagement with a seat to seal a passage to one of the servo motors. Movement of either ball off of its seat allows high pressure to flow to the respective servo motor. The high pressure fluid actuates the shuttle valve to port fluid from the other servo motor to the low pressure fluid source.

Abstract: A power shovel comprising a body; a front end assembly mounted on the body including a dipper; means for crowding the dipper; means for hoisting the dipper; and an energy regeneration system including an energy storing means and means actuated by a predetermined movement of at least one component of the front end assembly for charging the energy storing means, the energy storing means providing in the loaded condition a force applicable to a component of the front end assembly for at least biasing such component toward a predetermined movement.

Abstract: The invention is concerned with an improvement in a fluid controller for a power steering system which includes a housing having a fluid A for connection to the discharge side of a main fluid pump, an outlet for connection to the suction side of the main pump and a pair of ports for connection to the opposite sides of a dual acting hydraulic device such as a balanced cylinder of the power steering system for controlling the flow of pressurized fluid to the device. The controller includes a gear set which serves as a fluid meter or as a manual pump, depending upon the operativeness of the main fluid pump, and a spool valve shiftable axially to control the flow through the inlet, the gear set, the cylinder ports and the outlet. A control shaft is mounted for rotation on the housing responsive to movement of a steering wheel and is coupled to the spool valve for effecting axial shifting of the spool valve in response to rotation of the control shaft.

Abstract: Flow sensing and control apparatus is provided to selectively combine the fluid output of an auxiliary pump with a hydraulic system. The apparatus includes a valve body having a primary pump passage therein through which fluid from one of a pair of primary pumps is conducted to its respective inlet of a control valve, an auxiliary pump passage interconnected between the auxiliary pump and the primary pump passage and a fluid receiving passage which is connected to the auxiliary pump passage. A pilot operated valve is disposed within the fluid receiving passage and operative in response to fluid flow through the primary pump passage for selectively controlling fluid to the fluid receiving passage so as to permit the combining of any available fluid from the auxiliary pump with that of the primary pump up to a predetermined minimum flow rate through the primary pump passage and for diverting any excess fluid from the auxiliary pump to the receiving passage above that necessary to maintain the minimum flow rate.

Abstract: A hoist system employing a hydraulic motor, a variable displacement reversible flow hydraulic pump for supplying hydraulic fluid to the hydraulic motor, and an electric motor employed as a prime mover for the pump has a control arrangement effective for sensing various indicia of operation as, for example, rate of speed of lifting of an associated load, failure of the hoist system power train and the lifting of maximum loads. Within the overall control arrangement means are provided for comparing the actual rate of speed of lifting to the desired or requested rate of speed of lifting with the differential thereof being directed back to the associated mechanism for varying the output displacement of said hydraulic pump for thereby modifying such output displacement in order to achieve zero differential output. Means are also provided for automatically braking the hoist drum in order to prevent the load carried thereby from dropping in the event of a failure of the said power train.

Abstract: A valving arrangement for a winch motor powered by air or other pneumatic uid. The valving arrangement includes normally closed valves in the working fluid lines which are held open by air in the pilot fluid lines. In the event of a rupture or break in the pilot line, a normally closed valve is allowed to close, thereby stopping the winch and preventing it from overrunning its travel limits.

Abstract: An emergency hydraulic system for use in a vehicle having an engine which not only powers the vehicle but also drives a main hydraulic pump to supply hydraulic fluid under pressure to a hydraulic control means is disclosed. The emergency hydraulic system includes an auxiliary hydraulic pump driven by an electric motor to provide an auxiliary source of hydraulic fluid under pressure to the hydraulic control means under emergency conditions. An electrical control circuit for the electric motor is described which control circuit will automatically activate the electric motor whenever the engine is operating normally but the flow of hydraulic fluid from the main hydraulic pump falls below a given level and will automatically inactivate the electric motor whenever the engine is operating normally and the flow of hydraulic fluid from the main hydraulic pump is above a given level.

Abstract: In an earthmoving scraper a low volume, low pressure, pilot pump supplies fluid pressure to a pilot control valve which routes this fluid through bleed lines to a remote scraper control valve that operates the bowl jacks on the scraper from a separate source of pressurized hydraulic fluid. By manually varying the bleed rates of the output of the pilot pump with the spool of the pilot valve, proportion actuation of the control valve can be obtained through differential pressures in the bleed lines connecting it to the pilot valve. A safety valve connected in the bowl carry circuit supplies an alternate source of fluid pressure to the pilot valve if the pilot pump fails, ensuring positive fail-safe operation of the system.

Abstract: A fluid control circuit for a radio controlled vehicle for operating an engine, transmission, steering, movable elements of earth-moving machines and braking device of the vehicle by means of radio control. The control circuit has plural shuttle valves interposed between brake cylinders and solenoid operated valves for controlling the brake cylinders. A circuit changing valve is interposed between a conduit communicating with the source of fluid under pressure and conduits communicating with operating cylinders for the engine, transmission, steering, earth-moving machines and braking devices through respective solenoid valves and the shuttle valves. Circuit changing valve is manually operable for selectively feeding fluid in pressure from the source thereof to either conduit communicating with the respective operating cylinders. Thus, the remote control of the vehicle can be simply changed to a manual one or vice versa by a single operation.