Abstract: A redundant, dual-fail/operate fly-by-wire control system actuates a redundant tandem piston actuator (10) to provide a single composite output evidenced by movement of a piston rod (12). The basic fault-tolerate actuation system consists of dual hydraulic primary actuators, quadruplex electrical control loops (14-17), and control servo valves (22-25). A failure management system connects to the actuation system by means of lines (18-21) to control the servo valves (22-25). The four control loops (14-17) connect to a pilot controller that provides a pilot individual input signals to amplifiers (26-29) for each of the control loops. A tracking loop (450) includes switches (480, 482, 484) for connecting the four control loops (14-17) and providing isolation therebetween.

Abstract: A vacuum responsive switch for detecting a failure in creation of a control vacuum within the control diaphragm chamber. A solenoid valve is provided which functions to equalize pressure within one of a power diaphragm chamber and a leak chamber with the other when vacuum represented by a signal from the vacuum responsive switch is lower than a predetermined value.

Abstract: A hydraulic brake booster comprises a housing forming a pressure chamber and a pair of bores leading to the pressure chamber. One of the bores receives an output piston and the other bore receives a valve member. The valve member is movable by an input actuator to control communication of fluid pressure to the pressure chamber. The end of the valve member within the pressure chamber carries a sleeve and a poppet. The sleeve resiliently imparts movement to the valve member and the poppet cooperates with the sleeve to close communication to the pressure chamber in response to movement of the sleeve relative to the valve member.

Abstract: Disclosed herein is a power feed system for translating a rotary drill head along the length of a guide tower. The system utilizes a compound balanced area, end fed hydraulic cylinder as the actuating means. This arrangement provides a large ratio of fixed overall length to usable travel distance, balanced feed force in both directions, direct connection of the rotary head to the outer stage of the cylinder, and drift-free operation, all without the need for moving hydraulic hoses.

Abstract: A single acting steam engine wherein means are provided for auxiliary exhaust through the piston when an auxiliary exhaust poppet valve is open and the auxiliary exchange passages of the piston register with exhaust ports in the cylinder wall. The opening and closing of the auxiliary exhaust poppet valve are responsive to the rate of reciprocation of the pistons. A multiple of said engines may be utilized in combination to provide a multiple cylinder power plant. The engines drive a swash plate, which is formed with recessed, annular thrust surfaces. Projecting at right angles from the recessed, thrust surfaces are exhaust cams that engage valve stems through cam followers for actuating the same. The valve stems actuate the exhaust valves. The throat thickness of the swash plate between the recessed annular thrust surfaces is of uniform dimension along the circumferential paths thereof.

Abstract: A servo booster mechanism (18) having a piston (48) responsive to movement of a plunger (84) by an input signal for controlling the rate of fluid flow past a seat (82) into a passage (80) for distribution to the surrounding environment. A first restrictor (75) creates a first pressure drop in a supply fluid pressure P.sub.s to present an operational chamber (46) with fluid at a pressure P.sub.x. A second restrictor (openings 74-76) creates a second pressure drop in fluid pressure P.sub.x supplied from the operational chamber (46) to present control chamber (88) with fluid at a pressure P.sub.h. The difference in pressures combine to act on the piston (48) and plunger (84) to provide a constant force at stem (26), which provides a feedback to the input member (12), and provide a linkage (22) with a force to hold a position sensor (24) in a stationary position.

Abstract: In one form of the present invention, a plurality of serovalves are connected to a common manifold. The manifold transmits fluid pressure from the servovalves to a modulator piston which controls the fluid pressure applied to a hydraulic actuator piston. The servovalves are designed such that, if the fluid pressure provided by any one of them to the manifold falls below a threshold, then the servovalve disconnects itself from the manifold, allowing control of the modulator piston to be assumed by the remaining, functioning servovalves. The present invention can be used in control surface actuators of short takeoff and landing (STOL) aircraft.

Abstract: In a cylinder with two-step movement there is in a housing (7) a first piston (6) which slides in contact with the inside of the housing. A second piston (10), which supports a piston rod (11), which moves sealingly through a first end-piece (8) also slides against the inside of the housing. In the second end-piece (9) of the housing, there is a pressure medium tube (12) passing through the first piston (6) and which extends with its end distant from the second end-piece (9) into, and is guided against the inside of the tubular piston rod (11).

Abstract: A hydraulic vehicular transmission has a plurality of drive speed establishing devices (e.g. clutches) to be actuated for selecting a drive speed, and a pair of similar drive direction establishing devices to be actuated for selecting a drive direction. The drive establishing devices are all actuated and deactuated hydraulically by respective solenoid operated control valves via respective pilot operated valves. Since the solenoid valves are susceptible to malfunctioning, as in the event of trouble in the associated electrical circuitry, emergency control valves are interposed respectively between the solenoid valves and the pilot operated valves. Each emergency control valve is to be hand operated in the event of the malfunctioning of the associated solenoid valve for actuating or deactuating the associated speed or direction establishing device via the associated pilot operated valve. Additional features are incorporated for the greater utility of the transmission control system.

Abstract: A pneumatic servo booster including a housing, a power piston unit partitioning the interior of the housing into front and rear chambers and having therein a first passage with one end opening to the front chamber and the other end opening to the interior of the power piston unit and a second passage with one end opening to the rear chamber and the other end opening to the interior of the power piston unit, and a valve mechanism provided in the interior of the power piston unit and being associated with an input rod to control the communication between first and second passages and between the second passage and another passage which is communicated with a source of a first reference pressure. A plurality of diversion channels are provided in at least one of the first and second passages to decrease the speed of the air flow in the passage and to rectify the air flow thereby suppressing noise.

Abstract: A vacuum booster assembly in which a diaphragm member is coupled over a piston body at its inner peripheral bead and secured to the inner wall of a housing of the booster assembly at its outer peripheral bead, and an annular support plate is attached to one face of the diaphragm member and has an inner cylindrical portion coupled with the inner peripheral bead of the diaphragm member to fasten the same to the piston body. The annular support plate is made of thin sheet metal and formed at its radially inward circumference with an annularly pressed portion, and an annular reinforcement plate of thick sheet metal is integrally secured to the annularly pressed portion of the support plate and has an inner cylindrical portion coupled with the inner cylindrical portion of the support plate.

Abstract: An end cap for a cylinder including a body portion having an outer surface and first and second ends, a bore extending between the first and second ends, an annular sealing lip surrounding the bore, an annular recess surrounding the annular sealing lip, an annular outer body portion surrounding the annular recess, with the annular recess permitting radial flexing of the annular outer body portion both toward and away from the annular sealing lip, and an annular barb on the outer surface extending circumferentially about the annular outer body portion for reception in a mating groove in the cylinder.

Abstract: A transmitter cylinder is used in a hydraulic system and particularly the ake system of an automotive vehicle. To prevent undesired access into the transmitter cylinder, a lock part is installed at the pedal facing end of the cylinder. The lock part is an annulus. The pedal connected piston extends through the lock part and into the transmitter cylinder. The annular lock part is shaped so that its inner bore will guide and center the piston projecting into the cylinder. A locking element for holding the lock part in the cylinder bore is defined. It is either a radial projection from the lock part or it is a retaining ring held in a groove on the exterior of the lock part. In either case, the locking element projects into a groove defined in the interior of the cylinder bore, which retains the lock part in the cylinder bore against undesired extraction. The lock part may be a hollow annulus or a solid body. The lock part is appropriately configured to permit its extraction with appropriate tools.

Abstract: A system (10) of parallel hydraulic actuators (15) and (20) includes a pair of laterally spaced, longitudinally extending, discrete feedback levers (180) and (185) which independently provide feedback signals to a pair of actuator control valves (50) and (55) with enhanced accuracy and minimal lateral loading of the system.

Abstract: A force transmitting fluid actuator for use with a control device wherein an actuator member, movable within an actuator housing, actuates the control device due to the urging force of a plurality of pistons which can be selectively pressurized in unitary increments. The plurality of pistons are disposed within pressure chambers formed in the actuator housing in a symmetrical ring-shaped arrangement concentric to a single pressure chamber disposed on the vertical axis of the housing. A number of passageways interconnect the plurality of pressure chambers to form groupings of pressure chambers which act simultaneously in response to operation of a solenoid valve associated with each passageway. In addition to the symmetrical arrangement of the pressure chambers, the valve and passageway arrangement provide for a symmetric pressurization of the pressure chambers thereby resulting in a balanced force being exerted on the actuator.

Abstract: A cylinder for a valve actuator wherein the cylinder body has lugs connectable to and disconnectable from like cylinder head lugs by less than one turn rotation. Resilient seals seal the head to the body when connected, and the connection is releasably lockable.

Abstract: A hydraulic motor either of the radial or axial piston type is used for swivelling a hanging load about an upright axis. The motor has a distributor for controlling the flow of hydraulic fluid to the input and drain ducts of the motor. The motor further has hydraulic ducts extending from the stator to the rotor for transmitting fluid required for operation of the actuator of a gripping device or bucket. The distributor floats, so that radial and axial play as well as deformation of the rotor relative to the stator may be taken up without stress. At least some of the hydraulic ducts pass through the distributor, connections being made by suitable rotary transmissions and connecting points within the motor.

Abstract: In a cylinder apparatus for a rack and pinion type power steering mechanism of a motor vehicle or the like, including two pressure chambers defined in a power cylinder, there is provided means for making the effective pressure-applied areas of the two pressure chambers substantially equal to each other, whereby steering operation can be performed with accuracy and ease.

Abstract: A sealed-type automatic tensioner has a body assembly composed of upper and lower tubular bodies held in threaded engagement with each other, a tubular plunger slidably disposed in the body assembly, a piston slidably disposed in the tubular plunger and having a portion extending slidably through a hole in a top wall of the upper tubular body. The lower tubular body and the tubular plunger jointly define a larger-diameter hydraulic chamber, and the tubular plunger and the piston jointly define a smaller-diameter hydraulic chamber. A bottom wall of the tubular plunger has an aperture through which the larger- and smaller-diameter chambers communicate with each other. A compression coil spring is disposed in the first tubular body and acts between the top wall of the upper tubular body and the tubular plunger for normally urging the tubular plunger to move into the larger-diameter chamber.

Abstract: A control valve assembly for a pneumatic paving breaker which enables the maximum amount of energy to be imparted to the piston on its working stoke while restricting the energy imparted to the piston on its return stroke and which utilizes a reduced consumption of air, has an optimum speed of response and is relatively cheap to manufacture. This is achieved by having a valve member in the form of a pure cylindrical slug which reciprocates in a valve block in which it is a clearance fit.