Abstract: The invention relates to a hydraulic motor assembly which includes a hydraulic servomotor operable in either direction with a control valve. When the motor is operated in a selected direction, as distinguished from the return direction, it is desired that external forces acting on linkage connected to the piston of the hydraulic motor do not alter the speed of the piston. The control valve has two operating positions and two sets of supply and return passages which facilitate operation of the servomotor in either direction. A brake valve between one of the servomotor ports and the control valve has a scanning port which scans or senses the downstream pressure of either of the control valve supply passages, depending on the control position of the control valve.

Abstract: A fluid control cirucit for selectively varying the displacement of a variable displacement pump (P), such as the type employed in a hydrostatic transmission, comprises a primary control circuit connecting a pressurized fluid source (10) with the pump (P) and adapted to be actuated to selectively vary the displacement of the pump (P) between minimum and maximum values. A separate override control circuit is connected to the primary control circuit to override it to selectively vary the displacement of the pump (P).

Abstract: A piston for internal combustion engines, preferably made of aluminum or its alloys, having freely suspended piston pin bosses connected by first ribs to the piston head at points of zero moment and by second ribs to the piston skirt. The piston skirt has apertures in register with the bores in the piston pin bosses. The piston head is separated from the piston skirt by a transverse slot through at least a part of the circumference of the piston head and the ribs which connect the piston pin bosses to the piston skirt extend at an angle of 0.degree.-45.degree. to the boss plane.

Abstract: The safety system employs a shut-off valve, a control valve and a selector. The selector is formed of two non-return valves which are connected to the two chambers of the servomotor and has an output connected to one chamber of the control valve. Another chamber of the control valve is connected to the low pressure chamber of the servomotor while the intermediate chamber is connected to the shut-off valve in order to influence the movements of the piston of the shut-off valve. A solenoid actuates the control valve to deliver either high pressure fluid from the high pressure servomotor chamber or low pressure fluid from the low pressure servomotor chamber to the shut-off valve.

Abstract: An actuator system is disclosed which modulates a linear output shaft associated with a working control valve or the like in response to a control signal input. The system includes a feedback control link, a pneumatic positioner, a pneumatically controlled hydraulic valving system and a hydraulic cylinder and piston assembly controlled by the hydraulic valving system. The hydraulic valving system includes a three-position, four-way valve actuated by pneumatic binary output signals from a signal conditioner which is in turn controlled by the positioner. Hydraulic flow to the three-position, four-way valve may also be controlled from the signal conditioner in response to positioner output for most effective actuation of the hydraulic cylinder and piston assembly. Failure modes are also disclosed with the present system. The resulting system exhibits extremely rapid response times and high accuracy with dynamic stability.

Abstract: This invention pertains to a control valve (14) having a double-acting kick-out member (36) attached to an end of a spool (33) thereof to return the spool (33) to a neutral position after actuation thereof. The invention is particularly useful in a fluid control circuit (10) wherein the control valve (14) is adapted to selectively communicate pressurized fluid to an actuator (13), such as a double-acting hydraulic cylinder.

Abstract: The disclosure is of a system for operating a turbine without production of steam by compressing a gas, supplying the gas to the turbine, and returning the reduced pressure gas to the compressing means.

Abstract: A control member for supplying a pressure responsive device with pressurized fluid in response to an input signal. The control member has a housing with a chamber therein. The chamber is connected to a source of pressurized fluid through an entrance port, to a pressure responsive device through first and second operational ports and to the surrounding environment through an exit port. A lever located in the chamber has a bore therein that is connected to the entrance port to define a flow path for the pressurized fluid through the chamber. Depending on a desired operation of the pressure responsive device, an input signal is applied to the lever to bring the bore into communication with one of the first and second operational ports to allow pressurized fluid to flow to the pressure responsive device while the other operational port is connected to the surrounding environment through the chamber.

Abstract: A wave energy converting device disposed on the wave in the sea comprises a rotary shaft; a rotary hollow sleeve containing the rotary shaft therein; a plurality of partition walls for partitioning said hollow sleeve into a plurality of compartments; a plurality of radial plates each secured to the rotary shaft and said rotary sleeve to thereby form a plurality of water chambers; and plurality of first ports each formed in the rotary sleeve at the trailing end of each water chamber and adjacent to the radial plate corresponding to each water chamber.

Abstract: An engine piston and ring assembly providing improved oil control and where applicable sealing of scavenging air. In a preferred embodiment applicable to two-cycle port scavenged diesel engines and similar applications, the piston is provided with dual oil ring grooves near its open end, which is free from drain openings through the wall in the vicinity of the ring grooves to the oil cooled hollow interior of the piston. Drainage of lubricating oil scraped from the cylinder walls by the rings is provided instead by scalloped recesses in the lower wall surface extending from the open end of the piston to the nearest ring groove. The arrangement reduces leakage of scavenging air from the inlet ports to the engine crankcase as well as the occasional flooding of the piston rings with the cooling oil from the piston interior.

Abstract: A hydraulic fluid flow network, utilizing the fluid returned from by an open center hydraulic system, to augment the charging system of a hydrostatic transmission. The augmented charging system provides oil under pressure to flow into the charging system in the event that charging system pressure flow falls below normal. A back pressure is maintained in the return line header of an open center hydraulic system by a relief valve. Flow is diverted to the charging system by a line containing a non return valve.

Abstract: A packer nose assembly for pumping downhole equipment of the free type into and out of a tubing string located within a borehole. The assembly includes a mandrel having a lower end portion attachable to the downhole equipment and an upper end portion terminating in the form of a fishing neck. One or more packers are slidably received in a telescoping manner upon the mandrel and fixed in spaced-apart relationship respective to one another by spaced sleeves which are likewise slidably received upon the mandrel. Each packer is cylindrical in form and includes a resilient cup member which is affixed to the mandrel by a mount member. A marginal end of the cup is in the form of a lip which circumferentially extends about the mandrel and is biased into sealed engagement with the tubing wall. A marginal end of the mount member is in the form of a skirt which protects the cup member from damage.

Abstract: A throttle valve biased to open position by a spring is interposed in the return line of a steering control valve in a booster steering system. The essential feature of the invention is that one face of the valve is exposed to feed pressure acting against a valve opening bias spring to produce the throttling effect in accordance with construction and design of the valve and the system in which it may be used. The invention is particularly intended for use with booster steering control valves in neutral or steering position and ensures throttling of return flow to the system sump only during a steering operation. The invention is usable in steering mechanisms such as shown in the patent to Wagner et al., U.S. Pat. No. 3,964,371.

Abstract: An improvement is disclosed in a hydraulic system (10) having a variable displacement pump (12) and being capable of delivering pressurized fluid from the pump (12) to selectively engage at least three work circuits (18) with a first (20) of the circuits (18) being normally operable up to a first pressure and a second (22) of the circuits (18) being normally operable up to a second and lower pressure. The improvement comprises circuitry (80, 92, 94, 98, 108, 120, 122, 124, 126) for selectively operating a third (24) of the circuits (18) at one of the first or second pressures or at an upstaged pressure which exceeds the first pressure and circuitry (128) for reducing the displacement of the pump (12) in response to the third circuit (24) being operated at the upstaged pressure. Such upstaged pressure is available in a controlled manner for working against particularly heavy loads. Thus, a third and higher operating level is added to a system which already operates at at least two pressure levels.

Abstract: An engine starter drive assembly is disclosed of the type including a pinion gear moveable from a rest position to a driving position to engagement with gear teeth formed on an engine flywheel, the pinion adapted to be rotated by the starter motor in order to start the engine after engaging the flywheel teeth. In order to be properly located with respect to the flywheel gear teeth, the pinion gear moves axially into engagement with a fixed stop located at a predetermined position to produce proper engagement of the pinion with the flywheel teeth. The starter also includes an antidrift compression spring and washer assembly biasing the pinion gear against axial movement out of the retracted position. The disclosed starter assembly features a shielding cup supported on the fixed stop and extending towards the pinion gear hub extension to enclose the space therebetween, preventing the build-up of foreign matter tending to interfere with the axial movement of the pinion gear.

Abstract: An engine for operating a hydraulic motor. Opposed pistons, joined by a common connecting rod operating between two cylinders and between internal combustion valving and ignition components, are used to drive fluid under pressure through a series of cross-over valves to and from a hydraulic motor. Hydraulic fluid is stored and maintained under pressure within the engine cylinders on the other side of the pistons forming an internal combustion engine. A series of embediments within the common connecting rod actuate a matched set of proximity detectors. The proximity detectors, in turn, time the operation of the engines and the operation of the cross-over valves without mechanical linkages. A hydraulic pump is used to start the engine. A blower is used to mix the fuel and air within the engine and to exhaust combustion gasses. The hydraulic motor drives a flywheel to store energy and to dampen the pulsations resulting from the shifting of the cross-over valves and the reciprocating action of the pistons.

Abstract: A hydraulic circuit for a hydraulically driven vehicle comprising a pair of variable displacement pumps each driven by a common engine, a pair of variable displacement motors each connected with the respective variable displacement pumps in a closed loop circuit and driven thereby, a fixed displacement charge pump driven by the engine, and a pair of shuttle valves each connected in parallel with the respective closed loop circuits and has formed therein a neutral position and two offset positions wherein in the neutral positions of the shuttle valves both the closed loop circuits are connected with each other through the shuttle valves.

Abstract: A pair of pumps deliver pressurized fluid to a steering control valve assembly controlling the operation of a steering cylinder. The steering control valve assembly diverts any excess of the incoming pressurized fluid to a hoist control valve assembly controlling the operation of a pair of implement hoist cylinders. The hoist control valve assembly also diverts any excess of the incoming fluid away from the hoist cylinder pair, this time to a retarder or brake system for cooling same. The retarder receives additional cooling fluid from a hydraulic torque converter, to which the fluid has been forced from another pump. On leaving the retarder the pressurized fluid is cooled and then delivered to a transmission lubricating circuit.

Abstract: A hydraulic system (9) includes a hydraulic motor (10), a main control valve (17) for controlling said motor (10), a make-up valve (78,79) operatively associated with said main control valve (17) and a vent line (93,94,95,99) for selectively venting said make-up valve (78,79). In such hydraulic systems, and in particular, in prior art hydraulic systems used to raise and lower a load, there is always the possibility that should hydraulic pressure not be maintained in the vent line the make-up valve could come open and the load could unexpectedly move. Such a situation could occur with, for example, air trapped in said vent line and the simultaneous failure of a pump of the system. The present invention solves this problem by providing pressure maintaining arrangement (200) in fluid communication with said vent line (93,94,95,99).

Abstract: The present invention relates to a control unit for a vehicle powersteering mechanism comprising a housing having an inlet for connection to a source of fluid under pressure, an outlet for returning hydraulic fluid under pressure to said source, a pair of ports for connection to a hydraulic servomotor the movement of which controls the steering of the dirigible wheels of the vehicle, a hydraulic motor provided with a rotatable element and a follower element in operative combination with a distributor valve means provided with at least one displaceable body, said combination being operable on rotation of a control shaft connected thereto to divert hydraulic fluid flowing from said inlet through said housing to said outlet to one of said ports, and thus to its associated chamber of said servomotor, via said hydraulic motor, the hydraulic fluid being exhausted from the other chamber of the servomotor to said outlet, via said other port.