Abstract: A fail-safe actuator mechanism has an actuator housing encapsulated within a tank which stores a pressurized fluid media. Ports of the actuator housing are put into selective fluid communication with both the interior and exterior of the encapsulating tank by a valve at selective pressures.

Abstract: The invention relates to a reaction or open center type hydraulic steering control system which is adapted for use with a bidirection differential type servomotor having a piston rod extending from only one side thereof. A loaded check valve in a selected one of the lines to the servomotor compensates for relatively low above atomospheric pressures sometimes present in the line leading from the open center passage of the control unit to the exhaust tank when the control unit is in a neutral position.

Abstract: The invention is an integrated hydraulic control circuit for actuating the thrust reversers and variable exhaust nozzle on high preformance gas turbine engine powered aircraft. The hydraulic circuits for both systems are integrated into a single housing and are served by common elements. The circuit for the deployment and stowage of the thrust reverser buckets is hydraulically sequenced inhibiting the application of hydraulic power to the actuators prior to withdrawal of the locking pin. In a like manner, the thrust reversers must be fully retracted before the locking pin is deployed. The hydraulic circuit for the thrust reversers also includes a pressure compensating circuit which reduces the pressure applied to thrust reverser actuators with the thrust reversers in the stowed position.

Abstract: Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse.

Abstract: A vacuum pump assembly which is driven by pulsating exhaust gases emanating from an internal combustion engine is disclosed. The pump assembly includes a double-acting pump means for pumping air from a vacuum source and having a reciprocable pumping member, an actuating means including a reciprocable actuating member drivingly connected to the pumping member and which is driven through first and second strokes to move the pumping member through first and second strokes, respectively, one side of the actuating member being in communication with the exhaust gases and with the actuating and pumping members being movable through their first strokes during the pressure increasing phase of each pressure pulsation and being moved through their second strokes by a nonlinear variable rate air spring means during each pressure decreasing phase of each pressure pulsation.

Abstract: A vacuum pump assembly which is driven by pulsating exhaust gases emanating from an internal combustion engine is disclosed. The pump assembly includes a staged pump means for pumping air from a vacuum source and having a reciprocable pumping member, an actuating means including a reciprocable actuating member drivingly connected to the pumping member and which is driven through first and second strokes to move the pumping member through first and second strokes, respectively, one side of the actuating member being in communication with the exhaust gases and with the actuating and pumping members being movable through their first strokes during the pressure increasing phase of each pressure pulsation and being moved through their second strokes by a nonlinear variable rate spring means during each pressure decreasing phase of each pressure pulsation whereby the pump assembly is operable to pump air from the vacuum source throughout a wide range of engine speeds and loads including high speeds and loads.

Abstract: A piston for a precision dosing instrument includes a cylindrical core which may be made of glass, ceramic or metal, and a precision ground sleeve of polytetrafluorethylene disposed over the core. One end of the sleeve is closed while the core is open at both ends but the openings may have different diameters.

Abstract: This relates to a pneumatic feed system for moving a labeler head of a labeling apparatus for depositing labels in mold halves of a blow molding apparatus. The relatively heavy labeler head must be rapidly accelerated and then rapidly decelerated and at the same time moved sufficiently so as to provide for a large number of back and forth cycles per minute. There is provided in association with compressible shock absorbers a pneumatic system including a high pressure supply and a low pressure supply together with throttle valves such that the gas in the unpressurized end of the cylinder is rapidly compressed near the end of the stroke to function as a shock absorber and further, the cylinder is of a much larger diameter than that required for moving the labeler head so as to permit for the rapid acceleration as well as the rapid deceleration.

Abstract: A jacking mechanism for jacking a well casing or other well pipe vertically, and including a hydraulic control system in which a reversible variable displacement pump acts in one condition to deliver pressure fluid in parallel with another pump to the lower end of a jacking cylinder to actuate the piston thereof upwardly, with fluid discharging from the upper end of the cylinder to the variable displacement pump and being metered therethrough to regulate the rate of upward movement of the piston. In a second condition of the apparatus, flow through the variable displacement pump is reversed to lower the piston, and a variable restriction valve regulates discharge of fluid from the lower end of the cylinder to act with the variable displacement pump in regulating downward movement of the piston and supported pipe.

Abstract: Pressurization of closing and opening chambers of a door operator is controlled by first and second magnet valves coupled to the source of air. These valves are alternately energized by a switching network, e.g., a flip-flop, when sequentially actuated to close and open the door. The second magnet valve is biased to its vent position but the first valve is operated to its vent position by air through a double check valve when the second magnet valve is energized. Emergency and choke valves are inserted in series in the air supply to the magnet valves and normally pass air without restriction. Operation of the emergency valve, e.g., door blocked, shuts off air from the magnet valves and diverts that air to inhibit all output from the switching network and, through the check valve in opposite position, to operate the first magnet valve to vent position. Door operation is halted in position.

Abstract: A negative pressure booster for an automobile brake system includes a housing having an inside cavity, a power piston being provided in the housing for dividing the inside cavity of the housing into a suction pressure chamber and an atmospheric pressure chamber. An output rod is associated with the power piston and extends outwardly through the housing. A manually actuated control valve is carried by the power piston for controlling the communication between the suction pressure and atmospheric pressure chambers and the communication between the atmospheric pressure chamber and atmosphere. A pipe is provided for connecting the suction pressure chamber with a source of negative pressure.

Abstract: A fluid flow control system includes a priority valve which is controlled by a pressure differential applied across the valve, and which directs priority flow to a steering circuit and excess flow to an auxiliary circuit. The system insures that during steering, a relatively high pressure differential is required to shift the priority valve away from a priority steering position in which all fluid flow is delivered to the steering circuit. It also insures that when the flow to the steering circuit is sufficient to satisfy the steering demand, and the valve is also directing flow to the auxiliary circuit, a lower pressure differential is required to shift the valve in a direction for increasing the flow to the auxiliary circuit.

Abstract: A lift truck is disclosed with a changeable speed electric motor for driving a single positive displacement pump to supply the power steering and various work handling hydraulic load circuits. Manually actuable selector means are operatively connected with the load circuits and a speed range control means is operatively connected with the selector means for energizing the electric motor in different speed ranges according to the actuation of the selector means. A priority demand valve is connected between the pump and the respective load circuits and supplies fluid to the load circuits, giving priority to the power steering circuit. The speed range control means includes speed regulating means for the electric motor. The motor is energized from the battery and the regulating means includes a pulsing circuit with a motor current feedback to vary the mark/space ratio of the pulses produced by the pulsing circuit.

Abstract: A pneumatic control system for machines that provides precise incremental or continuous direction, position, velocity and acceleration control of a variety of machine functions, such as rotary or linear motions, tool positioning and the like. A compressed air supply is maintained accurately at a preselected minimum pressure necessary for a particular operation, by a digitally pulsed air flow control system. Air flow and pressure to the associated actuating mechanisms is also controlled by a digital dithering technique using individual sharp pulses of air, each of which instantly breaks the static friction of the mechanism and causes a discrete precise increment of movement, with rapid consecutive pulses providing continuous motion. The direction, amount, acceleration and speed of travel are controlled by varying the pulse width and rate of air flow and pressure as necessary and for efficiency in air consumption.

Abstract: A control system for a hydraulically driven vehicle having a variable displacement hydraulic motor connected with a variable displacement hydraulic pump in a closed loop and driven thereby.A spring-applied and fluid-released brake is mounted on an output shaft of the motor. A regulator is operatively connected to the motor for controlling the displacement thereof in response to a fluid pressure at both ports thereof. When fluid pressure at either one of the ports of the motor exceeds a predetermined level, the variable displacement motor is changed over to a high displacement position thereby generating a large braking force when the vehicle is to be stopped.

Abstract: A hydraulic control system comprising a hydraulic actuator having opposed openings adapted to alternately function as inlets and outlets for moving the element of the actuator in opposite directions and a variable displacement pump with loading sensing control for supplying fluid to said actuator. A pair of meter-in valves are provided to which the fluid from the pump is supplied and a pilot controller alternately supplies fluid at pilot pressure to a meter-in valve for controlling the displacement of movement of the meter-in valve and the direction and velocity of the actuator. Alternately pilot pressure from the pilot controller is applied simultaneously to both of the meter-in valves in conjunction with the venting of one of two load drop check valves to provide a regenerative mode.

Abstract: A pressure override control which utilizes pump output flow for destroking of a variable displacement pump to minimize loss of power and generation of heat and which includes modifications to the displacement control valve for the pump and, particularly, the cross connection of displacement-controlling servo motors when the displacement control valve is in a neutral position with blocking of communication of said servo motors to a displacement control pressure and drain whereby the pump cannot be positioned in a maximum displacement position in response to certain system malfunctions in the power override control circuitry.

Abstract: An hydraulic supply circuit for a vehicle power steering system of the type having a steering actuator and control valve therefor with hydraulic input, sump and overflow (by-pass) connections and in which any fluid not actually consumed by the actuator is diverted to the overflow connection. A positive displacement pump is provided having an output line connected to the input connection of the steering system. An accumulator having a charging line and a discharging line is used to supply fluid pressure in lieu of the pump. To control flow of fluid to and from the accumulator a charge-discharge valve is provided having charge and discharge modes. In the charge mode the accumulator is charged by the overflow and in the discharge mode pressure fluid is supplied from the accumulator to the input connection for maintaining the steering system in operation while blocking the overflow.

Abstract: A fluidic bearing seal assembly comprised of a plurality of floating back ring seals positioned in a plurality of annular grooves in a piston with at least one free-floating sealing wedge fitted to the outer peripheral edge of each backing ring for sliding along the cylinder wall. The piston has an inlet port and one way check valve means in the head thereof through which the working fluid is compressed during the compression stroke into a plurality of passageways that route the working fluid under pressure against said plurality of floating backing ring seals and into a pressure reservoir directly in contact with the cylinder wall and between adjacent backing ring seals to press the backing ring seals and seal wedges against the cylinder wall during the compression stroke and release the pressure from the ring seals and wedges during the return stroke of the piston.

Abstract: All but the circle drive motor of the implement actuators of a motor grader are divided into two groups each consisting of those which need not be operated simultaneously. The power system has three fixed displacement pumps for driving the circle drive motor via a circle control valve and the two implement actuator groups via respective implement control valve arrangements of carry-over parallel configurations. One of the pumps is connected to the two implement control valve arrangements via a restriction and a flow divider. A first demand valve controls communication between the other two pumps and the implement control valve arrangements in response to the pressure differential across the restriction, maintaining constant fluid flow to the valve arrangements regardless of engine speed or the loads on the implement actuators.