Abstract: A multi directional actuator capable of moving a shaft in at least two directions independently including one linear and one rotary movement. A base plate is provided to receive a first actuator having a linearly moving shaft which is extended from and retracted into the actuator. A second actuator is connected for movement by the first actuator and where the second actuator operates an output shaft which is selectively rotated through a portion of an arc. A guide arrangement is provided to direct movement of the second actuator by the first actuator and to journal the shaft of the second actuator to prevent orbiting and deflection of the shaft of the second actuator. Limit switches can be provided to indicate end of the stroke of the linear and rotary actuators and the first and second actuators can be separated to allow use of limit stops to limit rotation of the shaft of the second actuator.

Abstract: An intensifier cylinder including a body structure defining a first bore, a first piston structure including a piston mounted in the first bore and a piston rod secured to the piston and extending at its forward end through an end wall of the body structure, a second bore defined in the body structure, a second piston structure including a second piston mounted in the second bore and a second piston rod secured by the second piston and movable at its forward end into the first bore upon stroking of the second piston in response to the introduction of pressurized gas into the second bore to seal off and act upon hydraulic fluid in the first bore to produce an intensified force on the first piston structure.

Abstract: The mixing apparatus, which is constructed like a known mixing apparatus with return grooves (18, 19) in the control piston (2), has return grooves (18, 19) of a length which is equal to the distance between the inlet and return openings (4to 7) to be connected by it, the control piston (2) being able to be moved into an intermediate position (B), in which the return grooves (18, 19) connect the inlet openings (4, 5) to the assigned return openings (6, 7), and into a further advanced clearing position (C), in which the return grooves are no longer connected to the return openings. Due to the short return grooves, the length of which is no longer dependent o the length of the mixing chamber or of the outlet pipe of the mixing chamber, the overall length of the mixing apparatus is shortened. It is then only twice the stroke of the control piston. The neck region of the control piston is shortened, as a result of which the area of adhesion is reduced.

Abstract: A multi-stage hydraulic actuator including a cylinder body having an outer cylinder and an inner cylinder provided in the outer cylinder, first and second pistons inserted in the outer cylinder to independently move and provided with first and second working members, and third and fourth pistons inserted in the inner cylinder to independently move and provided with third and fourth working members.

Abstract: The dual area brake actuation piston mechanism (10, 110) comprises a piston housing (12, 112) having therein a first bore (30, 130) disposed coaxially about a separate second bore (40, 140). A first piston (50, 150) is disposed within the first bore (30, 130) and extends from the first bore (30, (130) to a piston end (70, 170). A second piston (60, 160) is disposed within the second bore (40, 140) and extends to engage the piston end (70, 170). The bores (30, 40; 130, 140) have first and second bore openings (32, 42; 132, 142) for receiving pressurized fluid which displaces the respective pistons (50, 60; 150, 160). The second bore opening (42, 142) includes a valving mechanism (80, 180) to either restrict or prevent lower fluid pressures from actuating the second piston (60, 160).

Abstract: A linear actuator used in moving, for example, gate valves, sluice gates and the like, wherein an increased thrust is required during initial movement. The present invention includes, as part of the linear actuator, a novel booster piston movably disposed about a piston rod; further included on the booster piston is a thrust column disposed radially between the booster piston and the piston rod so as to define an annular fluid channel for enabling fluid to move upwardly so as to contribute a substantial additional thrust component to move the primary piston.

Abstract: A low-impact drive unit operates by air under pressure. It includes aligned working and pressure chambers. The working chamber contains a working piston and a working piston rod extending from an end of the chamber. The pressure chamber contains a rear outer piston having a cylindrical recess and a central bore. An inner piston is located in the cylindrical recess and has a main piston rod extending through the bore, a bore in a separator separating the chambers, and is affixed to the working piston, so as to move together. The main rod has a longitudinal passage which supplies air from the pressure chamber to the back of the working piston under certain conditions. After the working piston rod contacts a workpiece, force of air pressure on all three pistons act on the working piston rod. An air return passage is provided to return the various components to their initial position after the working operation is complete.

Abstract: A cam actuator for selectively moving cam elements axially between distinct operative positions in a circular knitting machine, the actuator including a series of adjacent pistions arranged along the axial line of displacement, and stop means for limiting the axial stroke of each piston in the direction of extension. Each piston co-operates with adjacent pistons in the series such that displacement of a given piston in the extend direction causes the remaining pistons located between the cam element and the given piston to be displaced in the extend direction by the stroke length undergone by the given piston.

Abstract: A hydraulic arrangement for controlling tilt and trim of an outboard drive. The hydraulic arrangement comprises a single cylinder assembly having a single bore inside wherein an upper portion of the bore has a relatively small diameter and a lower portion of the bore has a larger diameter. Two separate pistons, one in each bore portion, are supported for reciprocation. The smaller diameter piston has a piston rod that is directly connected to an element of the outboard drive, while the opposite end of the cylinder assembly housing is connected to an element affixed to an associated watercraft, so as to insure against any undesirable noise or undue wear in the system, and to afford a compact assembly.

Abstract: A fluid pressure operated friction clutch actuating system for releasing the clutch includes a pressure operator, an actuator mechanism, which mechanism is shown as including a housing having a pair of telescopic pistons acting on a force transmission member and reacting through the actuator housing on an end wall of the clutch housing. The force transmission member has a U-shaped recess through which the clutch output shaft and the bearing retainer pass so that the force transmission member is in force transmitting engagement with the clutch throw out bearing while the system is in its operative position in the clutch housing. The actuator pistons act on the force transmission member when pressurized to move the throw out bearing to release the friction clutch through its belleville spring.

Abstract: A piston assembly comprising a primary piston and a co-centric secondary piston. The pistons are received within a housing for reciprocating movement therein and relative to each other. The housing and the pistons are arranged for operating pressure to be applied to the secondary piston so as to drive both pistons within the housing. The secondary piston is provided with means enabling the operating pressure to be equalized across the secondary piston and at least one bypass passage extends through the secondary piston. The arrangement is such that upon completion of the stroke of the pistons pressure equalization occurs across the secondary piston which causes the pistons to separate. The bypass passage becomes fully operable subsequent to pressure equalization, whereby a fast return stroke is achieved.

Abstract: A three position actuator which is used to position the gear range control lever on a two speed transfer case. Three positions are required to achieve HIGH, LOW and NEUTRAL. Two individual air chambers may be selectively charged with compressed air to move two pistons along a common actuator rod to achieve linear translation of the control lever to selectively position the transfer case in HIGH, NEUTRAL or LOW range. The transfer case is shifted from LOW to NEUTRAL or HIGH to NEUTRAL by releasing the respective charge of compressed air thereby permitting a spring to shift the control lever to neutral. Thus, in the event of a failure of the system supplying the compressed air, the actuator will return the transfer case to NEUTRAL as required for towing.

Abstract: A pneumatic driver is disclosed. The pneumatic driver includes a frame and a shaft movable between an extended driving position and a retracted position relative to the frame. A first inflatable air bladder is supported by the frame. The first inflatable air bladder is operatively connected to the shaft so that when the first air bladder is inflated, the shaft is moved into an extended driving position. A second inflatable air bladder is supported by the frame and operatively connected to the shaft. When the second air bladder is inflated, the shaft is moved to a retracted position. A valve manifold operatively connects first and second air bladders for controlling inflation and deflation of the air bladders. The frame includes longitudinal guide rods and transverse frame members fixed to the guide rods. A shaft support member having the shaft mounted thereto is slidably mounted on the guiderods. Support rods are mounted to the shaft support member by bolts received in orifices to provide a clearance fit.

Abstract: Actuator (14) drives inlet vanes (22) selectively to three positions, using high (58) and low (56) pressure fuel as the driving medium. Each of the three position is externally adjustable (94, 92, 68). An overboard leak path (86) is provided at the most often sliding seal.

Abstract: Described herein is an internal mixer of the type including a mixing chamber rotatably accommodating mixing rotors therein, a hopper frame erected on the mixing chamber, a charge hopper provided on one lateral side of the hopper frame for charging a mixing material therethrough, and a floating weight provided in the hopper frame for upward and downward movements therein, the floating weight being held in an upper lifted position when charging a mixing material into the mixing chamber and then lowered into a pressing position in a mixing stage to apply pressure on the charged material in the mixing chamber, wherein the floating weight is dimensioned to have an axial length sufficient for closing an inlet opening formed in the side wall of the hopper frame in communication with the charge hopper, when in the lower pressing position, and lift means for lifting the floating weight up and down in the hopper frame is provided separately from a pressing means with a function of pressing the floating weight resilient

Abstract: A remote control shifting system for a mechanical transmission. The transmission is operated by two pneumatic cylinders, a selecting cylinder operating in the direction of shift path selection and a shifting cylinder acting in the direction of shifting. The shifting cylinder operates with two force stages, a lower force for effecting synchronization of gears about to be engaged, and a higher force level for actually engaging or disengaging the selected gears. A remote shift control unit is designed to closely emulate the action of a direct-operating manual shift level. During the synchronizing phase, the shift lever moves easily in the shifting direction. After a preliminary movement, however, further movement is allowed only against considerable resistance, as if conventionally mechanically forcing gears into meshing engagement.

Abstract: A multi-stage air pressure cylinder is made of superposed components tightly fastened together wherein additional stages can be added by superposing additional components. The two-stage cylinder comprises two end wall members each having a cylindrical recess facing each other and divided by a fixed partition wall having a perforation therethrough. The partition wall and the end wall members are tightly fastened together. The partition wall subdivides two compression chambers. A piston is located in each compression chamber. One piston has a projection extending outside the cylinder and the other is adapted to exert a mechanical pressure on the first one while fluid pressure is exerted on both pistons.

Abstract: The present invention includes a three position actuator which is used to position the gear range control lever on a two speed transfer case. Three positions are required to achieve HIGH, LOW and NEUTRAL. Two individual air chambers may be selectively charged with compressed air to move two pistons along a common actuator rod to achieve linear translation of the control lever to selectively position the transfer case in HIGH, NEUTRAL or LOW range. The transfer case is shifted from LOW to NEUTRAL to HIGH by releasing the charge of compressed air thereby permitting the return spring to shift the control lever to HIGH gear range. Thus, in the event of failure of the system supplying the compressed air, the actuator will return the transfer case to HIGH gear range which provides an appropriate gear range selection for limp home mode.

Abstract: A clutch actuating device in which an actuating piston coupled via actuating members with a clutch release bearing and, at an axial distance to this, a compensating piston are longitudinally displaceably guided in a hollow cylindrical housing, which pistons are held at a distance by a pressure spring and together with a section of the cylinder wall of the housing delimit an actuating oil chamber connected to an external oil reservoir, characterized in that the compensating piston with its side opposed to the actuating piston delimits a compensating oil chamber formed by the bore wall and the housing bottom, the actuating oil chamber and the compensating oil chamber being connected by an oil passage which is regulated both as a function of the distance between the pistons and of the operational state, the actuating oil chamber being connected with a pressure oil source and the actuating piston and the compensating piston being additonally coupled with each other in the axial direction by connecting means which

Abstract: A fluid pressure operated positioning apparatus has a cylinder (1), formed as an annular cylinder, with an outer cylinder wall (2) and an inner cylinder wall (3) coaxial with and spaced apart radially from the outer cylinder wall. In the annular cylinder, a piston arrangement including at least one ring piston (8) is slidably guided, its ring piston surrounding the inner cylinder wall and being connected to at least one elongated force transfer element (22) that is extended in a sealed manner out of the annular cylinder.

Abstract: An actuator for opening and closing the gate of a surface safety valve includes a primary piston and an auxiliary piston. The primary drive piston is directly connected to the valve stem, while the auxiliary piston is slideably connected thereto. Extension movement of the auxiliary piston is stopped by a divider plate after initial breakaway forces are overcome. The thrusting force developed by the auxiliary piston during a valve opening operation is transmitted to the valve stem and the primary piston by a shuttle sleeve. The shuttle sleeve is radially spaced about the valve stem, thereby defining a bridge annulus which maintains fluid communication between the primary pressure chamber and the auxiliary pressure chamber at all times. The thrusting force produced by the auxiliary piston is combined with the thrusting force produced by the primary piston to break the static gate seal and overcome the gate drag during a first stage of operation.

Abstract: Herein disclosed is a brake system for use with an automatic transmission for braking a rotatable member such as a brake drum, which is accommodated in a casing and connected to the sun gear or the like of a planetary gear mechanism, by bringing a brake band having two ends into contact with the outer circumference with the rotatable member.

Abstract: A control (220) for providing a dual pressure source (236) of pressurized fluid to a pressurized fluid operated shift actuator (30) for a mechanical change gear transmission (202) is provided.

Abstract: An apparatus for feeding a liquid from a reservoir is provided. A distribution duct that defines a channel extending from the reservoir is provided that is in fluid communication with a feeding duct that defines a channel. A valve seat is located between the distribution duct and the feeding duct. The channels defined by the distribution and feeding duct extend in the same plane at the valve seat. The valve seat is located at an acute angle with respect to that plane. A closing device, for regulating fluid flow from the distribution duct to the feeding duct is provided. The closing device includes a movable valve, movable in a direction that is at an acute angle to the flow if the fluid from the distribution duct to the feeding duct, for mating with the valve seat. A member is coupled to the valve for urging the valve toward the valve seat. Members are provided for adjusting the member for causing the closing device to move.

Abstract: An improved spring brake construction is formed by a pair of concave metal housng portions having peripheral lips. Once the internal components of the spring brake are assembled within the housing portions, the lip of one housing portion is spun over the lip of the other housing portion to capture and grip it, thereby permanently sealing the housing portions together. The push rod and coil spring within the spring brake are maintained in axial alignment by a central indentation in one of the housing portions that extends coaxially within the coil spring, and by the construction of the spring diaphragm with a central axial protrusion which extends into a central opening in a spring plate on the side of the diaphragm facing the coil spring. On the opposite side of the diaphragm a push rod seat is laterally restrained from movement relative to the diaphragm.

Abstract: A pneumatic drive for punching, cutting and stamping devices, which have two tool parts which can be moved toward one another, and of which preferably one, at least in the operating position, is fixedly connected to the machine frame, is constructed such that an opening gap, which is as large as possible, is created. Furthermore, when the tool parts are moved together, the pneumatic drive is operated at a low pressure, so that additional safety devices are not needed. A pneumatic cylinder is secured on the movable tool part for this purpose, the piston rod of the pneumatic cylinder being constructed lockably in at least one end position. The piston rod of a pressure clamping element is secured on the piston rod exiting from the pneumatic cylinder. The cylinder of the pressure clamping element is arranged or fixably stationarily and consists of at least two piston cylinder units with one common piston rod, which piston cylinder units are connected one behind the other.

Abstract: A fluid-pressure-operated, three position working cylinder includes a cylindrical housing having a graduated bore formed therein and a movable primary piston dividing the bore into first and second pressure chambers. A movable secondary piston surrounds a portion of the primary piston and moves relative to the primary piston within the limits of a piston stop arrangement formed on opposing surfaces of the pistons. The piston stop arrangement includes an elastic stop on the primary piston which interacts with a sloped stop formed on the secondary piston so that upon initial insertion of the secondary piston onto the primary piston, the sloped stop compresses the elastic stop. The sloped stop includes a lip portion that can contact the elastic stop so as to restrain the secondary piston from further movement in one direction relative to the primary piston. A vent passage formed in the housing allows venting of the space between the two pistons.

Abstract: A safety relief system for a valve in a vent or a main flowline. The safety relief system utilizes a main actuator (24) utilized primarily for a positive pressure condition and a vacuum actuator (96) in axial alignment with the main actuator (24) utilized exclusively for a negative pressure condition. The main valve member (18) has a stem (22) which extends within both actuators (24, 96) and diaphragms (26, 100) are connected to the stem (22) for movement of the valve member (18).

Abstract: Modular circulating and dead end color changers are made from synthetic materials inert to chlorinated hydrocarbon solvents. Universal supply and return manifolds have relatively smooth and uninterrupted walls defined, in part, by inlet and return valve surfaces, for easy solvent flow cleaning. Circulating high pressure color changes have improved actuators and circulating means including bypass lines for continuously recirculating both selected and non-selected paints. Valve sealing is enhanced by improved valves and pressure drop across each module is minimized by modular construction regardless of the number of modules used.

Abstract: A fluid-pressure driving device including a main actuator unit having a piston adapted to travel a full part of a predetermined stroke and an accelerating actuator unit having a piston adapted to travel only a part of the stroke and being capable of operating only during the acceleration of the object to be actuated. These actuator units are operated under the control of a control valve such that, in the accelerating range in which the speed of the object is still low, both actuator units operate to produce a large actuating force, while, after the acceleration, only the main actuator unit operates to fully travel the required stroke.

Abstract: A piston type pneumatic powered actuator (9) for operating a valve (10) of the expanding gate type wherein velocity of the piston-stem-gate drive train is maintained substantially constant in the latter stage of the actuator stroke. The actuator (9) includes an assembly of dual pistons (61,75) which are adapted to be driven by fluid pressure in one direction to operate the valve but are returned by spring means (66,67) when the fluid pressure is removed. A drive piston (61) directly connected to the actuator stem (23) is nested within a primary piston (75) which is not connected to the actuator stem (23) but moves the drive piston (61) when actuating pneumatic fluid is applied to the actuator (9). A stop (85) affixed to the primary piston (75) is adapted to cooperatively engage the actuator housing (40) to terminate the stroke of the primary piston (75) prior to termination of the stroke of the drive piston (61).

Abstract: A dual stage hydraulic actuator (9) for actuation of an expanding gate valve (10). The actuator is mountable to the valve housing and comprises a housing 40 which defines a piston chamber 41 and a primary piston (61) slidably received therein. An actuator stem (23) connects the piston (61) to the valve gate assembly (20). A secondary piston (77), of smaller piston area than the primary piston (61), is slidably received in a piston receiving bore (75) which is formed in the fluid receiving face of the primary piston. A piston rod (80) connects coaxially with the piston (77) and extends through the end (52) of the actuator housing. The actuator is responsive to hydraulic fluid pressure which when applied through an inlet (71) of the actuator housing to one side of the pistons (61, 77) drives the actuator stem and gate assembly to an operational open or closed position of the valve.

Abstract: A positioning device capable of positioning a rod with a first piston fixed thereto into one of four positions selectively by means of a second piston disposed within a chamber A formed in a large-diameter cylinder portion and first, third and fourth pistons disposed within chambers B and C formed in a small-diameter cylinder portion. It is convenient to apply this positioning device to a select mechanism of a transmission or the like having four select positions.

Abstract: A parking brake, primarily for use with railway vehicles, including a friction clutch associated with a fast-travel nut which is locked by the clutch against rotation on a threaded spindle connected to a brake head, under a force exerted by a plurality of stacked Belleville-type disc springs. The spring load may be overcome by air pressure acting on respective faces of a plurality of serially connected pistons, which, in effect releases the fast-travel nut for free spinning to thereby accommodate axial displacement of the spindle during normal service application and release of the brakes.

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 drum brake hydraulic wheel cylinder assembly comprises a pair of piston assemblies and an abutment member. The piston assemblies are of the kind comprising an adjustable variable length tappet assembly having interengaged screw-threaded components. To enable thrust to be transmitted from one adjacent brake shoe to the other, i.e. for parking purposes, the abutment member is slidable in the cylinder bore against a spring centering device.

Abstract: The disclosure describes a new type of pressure cylinder to provide clamping force while fabricating deep drawn metal parts. The piston is a hollow cylinder connected to the clamping pad. The drawing tools are connected to the draw ram by a rod passing through the hollow piston. This arrangement provides a smaller overall press height and an axisymmetric clamping force. In addition, the symmetry of the parts described means that the wear parts can be reversed to double their useful lives.

Abstract: A hydraulic adjustment apparatus as is for instance used to adjust a roller of a rolling mill has a cylinder forming a first cylinder chamber and having a first cylinder surface directed backwardly in a predetermined direction in the first chamber. A first piston is displaceable forwardly and backwardly in the direction in the first chamber relative to the cylinder and has in this chamber a forwardly directed first piston face of a predetermined first piston area. The first piston is formed with at least one second chamber receiving a forwardly and backwardly displaceable second piston having a forwardly directed end engageable with the first chamber surface. This second piston in turn has a second piston face of a predetermined second piston area substantially smaller than the first piston area and directed backwardly in the second chamber.

Abstract: A pilot valve is disclosed having a piston actuating a valve element shiftable between a first and second positions. The piston is comprised of two concentrically arranged pistons, the larger piston having an internal bore with two sections of staggered diameters and a smaller, correspondingly shaped second piston inserted in the concentric internal bore. A single O-ring on the bottom of the second section of the first piston annularly mounted around the second section of the second piston seals the piston chamber from a fluctuating sensed fluid pressure. The first piston has a longer upper bore section than the second piston. A spacer is placed at the juncture of the first and second sections of second piston so as to enable the first and second piston to act in unison in actuating the valve element. In this mode, the effective surface area of the piston is equal to the diameter of the larger piston or of the O-ring.

Abstract: This valve actuator is primarily intended for use with rotary cut-off valves. It includes a housing which is attached to the valve body for receiving the valve stem and a longitudinal passage slidably mounting opposed piston elements. The piston elements include spaced shoulders which engage the remote end of a radial arm mounted within the housing and attached to the stem for rotating said stem. The radial arm includes a cam at the remote end having opposed cam faces alternately engaged by the piston elements and configurated to provide a minimum gap between the cam and the piston shoulders during the rotation of the valve between open and closed positions.

Abstract: A housing/piston mechanism for sensing a control fluid pressure and shifting a valve element in response thereto. The piston mechanism comprises a first piston having an internal bore in which is positioned a second piston, and a third piston for use in one specific orientation within the piston housing. Varying ranges of fluid pressure sufficient to actuate the piston mechanism are accomplished by positioning the piston mechanism within its piston chamber in varying orientations so that the effective piston surface area exposed to a control fluid is dictated by the specific orientation of the piston mechanism within the chamber. In one orientation, the effective fluid pressure surface area is that of the larger piston member. In a second orientation, the effective surface area exposed to the sensing fluid is a first surface of the smaller piston carried by the larger piston. In a third orientation, the effective surface area exposed to the sensing fluid is that of the opposite end of the second piston.

Abstract: A piston mechanism for sensing a control fluid pressure and shifting a valve element in response thereto. The piston mechanism comprises a first piston having an internal bore in which is positioned a second piston. Varying ranges of fluid pressure sufficient to actuate the piston mechanism are accomplished by positioning the piston mechanism within its piston chamber in varying orientations so that the effective piston surface area exposed to a control fluid is dictated by the specific orientation of the piston mechanism within the chamber. In one orientation, the effective fluid pressure surface area is that of the larger piston member. In a second orientation, the effective surface area exposed to the sensing fluid is a first surface of the smaller piston carried by the larger piston. In a third orientation, the effective surface area exposed to the sensing fluid is that of the opposite end of the second piston.

Abstract: An actuator device for actuating ejector of a scraper comprising a first actuator having a long stroke, a second actuator having a short stroke, said first and second actuators being connected and fixedly secured in series so that the piston rod of said second actuator can be brought into contact with the piston of said first actuator, and valve means which normally permits the communication between the delivery side of a hydraulic pump and a pressure chamber of said first actuator and which also permits the communication between the delivery side of said pump and the pressure chamber of said second actuator when the pressure within the pressure chamber of said first actuator has increased beyond a predetermined value.

Abstract: A hydraulically actuated gate valve having a hermetically sealed piston head adapted to receive a remotely operable actuator for overriding the valve to open the gate.

Abstract: A regulator for regulating the output of an output shaft is discosed, the regulator comprising a number of chambers to and from which working medium can be fed and discharged in dependence upon control means to effect axial movement of the output shaft via pressure transmitting elements.In accordance with the invention, the regulator comprises a number of series-connected units, the units providing fixedly spaced walls to define separated chambers through which the output shaft effectively extends, each chamber having at least one pressure transmitting element therein which is connected directly or indirectly to said output shaft. With such an arrangement the or each pressure transmitting element, when activated, exerts either individually or in unison an axial force on the output shaft substantially corresponding to the sum of the forces exerted on the active pressure transmitting elements.

Abstract: The present invention relates to hydraulic prestressing nuts for setting a tensile stress in a bolt whereon the nut of the present invention is turned. The invention involves a nut body wherein an annular piston is arranged to be hydraulically extended from a bottom face thereof against a plate, head, platen, or the like, elevating the nut and extending the bolt therewith. A concentric loading ring is arranged with the nut body for turning into engagement with the place, such that when the loading ring is so extended, it provides a rigid columnar support to the annular piston. Tensile stress on the bolt is maintained by the loading ring. The nut of the present invention further involves a failsafe arrangement for providing a backup repressurization capability consisting of a second piston arrangement that can be independently pressurized at a primary seal failure, extending the primary piston therewith.

Abstract: An electrohydraulic actuator has a power piston which is controlled from movement between the ends of its travel for performing work by servo control valve. When the actuator is not performing work, the power piston is abutted on one side by a pressure positioned centering piston which prevents the movement in one direction. High pressure fluid operates on the other side of the power piston to prevent movement in the other direction so that the power piston is centered in the cylinder and cannot be moved by external forces.

Abstract: A fuel injection system for an internal combustion engine is described, which provides for independent, flexible control of timing as well as quantity of fuel injected. The system is programmable for torque shaping and adaptable to a wide range of engine sizes. It uses piezoelectric valves for controlling injection timing, a shuttle, fuel meter and a gas driven high pressure pump for injecting the fuel into the cylinders.

Abstract: The invention relates to a hydraulic servomotor comprising a housing provided with a bore slidably receiving two pistons separating an actuating chamber from an utilization chamber, said pistons including an annular outer piston and an inner piston received within the annular piston. Releasable coupling means are provided between both pistons to permit said pistons to move in unison when high pressure fluid is available in the actuating chamber and to permit the inner piston to be moved alone by the push rod in the event of a high pressure failure in the actuating chamber. The motion of the outer piston towards the interior of the actuating chamber is limited by an abutment fixed to the housing.

Abstract: A control (220) for providing a dual pressure source (236) of pressurized fluid to a pressurized fluid operated shift actuator (30) for a mechanical change gear transmission (202) is provided.