Abstract: An electrohydraulic system for control of a variable output pump includes a microprocessor-based controller receiving inputs from condition sensors coupled to the pump and command inputs from a remote master controller. The controller supplies outputs to an electrohydraulic valve for metering hydraulic fluid to a pump control port and thereby controlling pump operation in any one of a number of preselected and prestored pump control modes. A hydromechanical valve is connected in parallel with the electrohydraulic valve for controlling pump operation in the event of electrical malfunction or failure. Circuitry connected between the pump condition sensors and the control computer prevents aliasing errors due to mismatch between the computer sampling frequency and pump speed.

Abstract: A hydraulic cylinder that is capable of being set in three positions utilizing a movable cylinder with a fixed main piston and auxiliary pistons slidably mounted within the cylinder. Right and left fluid chambers are defined, within the cylinder, by the main piston and right and left auxiliary pistons respectively.

Abstract: A single - stroke pneumatic apparatus comprises a hollow cylindrical frame 1) in which is mounted for reciprocating back and forth a striker (2) forming in the frame (1) front and rear chambers (3 and 4), the front chamber (3) has its own inlet and outlet ports (5 and 6) and the rear chamber (4) has its own ports (7 and 8). A directional flow control sleeve (10) fitted outside the frame (1) is arranged to uncover and cover the inlet and outlet ports (5, 6, 7, 8). The directional flow control sleeve (10) is provided with front and rear longitudinal internal passages (11 and 12) and front and rear radial holes (13 and 14).

Abstract: The present invention provides a protective device for a working member, such as the piston rod of a piston and cylinder actuator, which is arranged at least partly in a receiving member and is able to be moved and more especially slid, along a curved or straight path so that it projects to a greater or lesser extent out of the receiving member. The device is provided with a plurality of sleeve-like guard sections which surround the working member projecting out of the receiving member along the full length of the working member so that whatever the position of the latter any two adjacent guard sections overlap each other and are able to be slid in relation to each other, one of said guard sections being stationarily arranged on the receiving member and another guard section being arranged on the working member so as to move therewith so that in accordance with the actual axial extent of the part of the member to be protected the sections are telescoped into each other to a greater or lesser extent.

Abstract: A brake booster which includes a control slide that is displaceably supported in a servo piston and acted upon by a piston rod under the influence of brake pressure. The control slide has bores that establish communication between a pressure chamber and a pressure source or return for power brake fluid in the pressure chamber. The control slide is intended to penetrate a control bush in a stepped bore in the servo piston, which has a radial bore for connecting the pressure source with a radial bore in the control slide toward the pressure chamber. The control bush is supported radially movably in the stepped bore.

Abstract: A piston engine having a reciprocating piston, which is journalled in a radial direction with respect to the direction of translation by means of at least one dynamic groove bearing located within the piston and is separated from a compression space by an annular sealing gap at an outer surface of the piston. The piston engine is suitable for use in compressors and cryo-coolers, more particularly for cooling of computer processors.

Abstract: This relates to a positioning device for positioning a member relative to a work piece. In the preferred use of the positioning device, a sealing head is carried by the positioning device with the sealing head having a first lowered position for picking up a lid for a container and a second lowered position for positioning the lid and thereafter bringing the lid into pressure engagement with an associated container and effect the heat sealing of the lid to the container. The positioning device includes an extensible fluid motor of the piston and cylinder type which is mounted within a guide sleeve for selective vertical positioning by way of a cam follower and cam track and which extensible fluid motor is further selectively extensible so as to further move an associated member carried thereby downwardly and into resilient clamping engagement with the work piece.

Abstract: Continuous combustion heat engine including a compressor (12), combustor (14) and expander (16) which operates on a Brayton cycle with positive displacement pistons (90) in the compressor and variable expansion ratio pistons (190) in the expander. Compressor (12) delivers compressed air to the combustor (14) where it is mixed with fuel and combusted to produce expansion gases for the expander (16). Power input to the compressor and power output from the expander are achieved through the radially disposed pistons (90,190), connecting rods (94), cranks (98), crank shafts (100), planetary gears (104), sun gears (106) and sun gear connectors (114) which rotatably secure the sun gears (106) and manifolds (110,166) together. The pistons (190) for the expander have positive displacement sections (192) and free floating sections (200) for the variable volume ratio capability.

Abstract: The invention relates to an advancing or feed for moving a workpiece on a machine tool. The device comprises a stationarily arranged fluid power cylinder whose piston rod extending through one of the end caps of the cylinder is connected with a load driving member or carriage for carrying the workpiece. The outer face of the cylinder has at least two, generally diametrally opposite guide flats on which two flat bearer faces in the driving member run so as to preclude rotation if the driving member about the cylinder.

Abstract: Helical splined rotary actuator includes a pair of cylinder housings having inboard ends rotatably mounted in coaxial alignment on opposite ends of a center sleeve member. Contained within the housings are pistons having relatively large diameter helical spline connections with the inner diameters of the housings and smaller diameter straight spline connections with opposite ends of the sleeve member, whereby simultaneous axial movement of the pistons toward and away from each other causes relative rotation between the sleeve member and cylinder housings. The sleeve member may be connected to a first support intermediate the ends of the actuator. In like manner, the cylinder housings may be connected to a second support rotatable relative to the first support adjacent opposite ends of the sleeve member.

Abstract: The brake motor subassembly with automatic play compensation limitation by way of a stepped pilot piston (20), comprising a first cylindrical peripheral surface of larger diameter (21) sliding in an inner bore (7) of the control piston (1) and a second cylindrical peripheral surface of reduced diameter (24) interacting sealingly slideably with an annular gasket (17) in the piston (1), has an intermediate radial shoulder (26) which, during the movement of the pilot piston (20) because of the opposing effective cross-sections (s.sub.1, s.sub.2), interacts with the annular gasket (17) so as thereby to present a new effective surface (s.sub.3) preventing the continuation of the movement of the pilot piston (20) and thus avoiding the compression of the elastic member (11) which normally stresses the automatic compensation nut (14).

Abstract: The reciprocating pump is provided with a sleeve between the piston and the casing. The sleeve is disposed in spaced relation to define an annular gap both with respect to the piston and with respect to the casing. The sleeve is also biased by a spring into sealing engagement with the end wall of the casing. The end of the sleeve adjacent to the spring provides a permanent connection between the gap between the casing and sleeve and the pressure medium used to drive the piston of the pump so that the same pressure prevails on the inside and outside surfaces of the sleeve.

Abstract: An angioplasty pressure controller having a housing with a slidable pressure cylinder in it. A drive screw is connected to a piston in the cylinder and arranged for fine adjustment by turning the drive screw. An engagement slide to provide a rapid means to create pressure or vacuum. A connecting rod is attached at one end to the cylinder and at the other end to the plunger of a syringe. A pressure gauge is connected to the inside chamber of the cylinder.

Abstract: A fluid pressure actuated piston (78) is slidably carried in a fluid pressure actuated cylinder (50) which, in turn, is slidably carried in a fixed carrier or casing (21). Movement of the cylinder (50) is resisted by a breakable or displaceable coupler (90, 94, 184, 185) which engages the cylinder (50). Fluid pressure acting upon the cylinder (50) and piston (78) causes the coupler (90, 94, 184, 185) to break or be displaced and release the cylinder (50) for axial movement in the direction of movement of the pressure responsive piston (78).

Abstract: An extension and retraction system for a multiple section, telescoping boom apparatus of the type utilized for raising and lowering a work platform or basket. The innermost longitudinally movable section is carried by a longitudinally inextensible or base section, and is extensible and retractable relative to the base section by a dual cylinder assembly. Extension chains trained about sprockets carried by certain of the sections automatically extend the other extensible sections upon extension by the cylinder assembly of the innermost longitudinally movable section. Automatic and positive retraction of such sections is accomplished by retraction chains operating in response to retraction of the innermost section. The cylinders of the dual cylinder assembly are pivotally coupled at a pivot mount longitudinally slidable along a guideway carried by the base section to thereby accommodate deflections of the boom sections located between the opposite extremities of the dual cylinder assembly.

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 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: Apparatus for repeatedly dispensing measured portions of viscous substances is disclosed. The invention includes a body defining a bore within which is a sleeve defined floating measuring chamber. In the chamber is a sliding piston. Material to be dispensed is forced into the floating measuring chamber under pressure. A three-way, two-position air valve actuates the dispensing apparatus. Shifting of the air valve applies air pressure to one end of the floating measuring chamber, causing it to shift. This closes a material supply port and opens a material discharge port. The floating measuring chamber meters the flow of air to the floating piston so that the discharge velocity of the material being dispensed is controlled. At the end of the dispensing cycle, air under pressure is directed out through the material discharge port clearing it of residual material.

Abstract: A hydraulic cylinder comprising a hydraulically operated power lifting ram for lifting heavy loads further includes a guide cylinder concentric about and enclosing the ram, the guide cylinder being secured to the lift platform for further support of the load and reciprocating in unison with the ram under application of hydraulic pressure. The guide cylinder is equipped with a safety locking means which prevents the hydraulic cylinder and its load from lowering in the event of a sudden loss in hydraulic pressure. The safety locking means is in contact with the guide cylinder substantially during the full stroke of the hydraulic operated ram, providing a unique method of locking the cylinder in any position within tolerances normally associated with gear driven devices.

Abstract: This invention has for its object to eliminate the problem of loud noise and violent vibrations in machines having transient force characteristics of the type appearing in punching or cutting presses.According to the invention this is achieved by means of a damping device comprising a housing defining a chamber filled with a hydraulic fluid said fluid being pre-compressed by a first piston acted on by the force and said pre-compressing being carried out to a pressure corresponding the force to be dampened. Immediately before the force relief the force is arranged to act on a second piston of bigger cross sectional area said second piston preventing a too rapid force relief of the press frame due to the pre-compressed hydraulic fluid.The force relief occurs rather slowly due to the fact that the hydraulic fluid trapped in the chamber is exhausted via control valve keeping the pressure in the chamber almost constant and only permitting a certain volume flow therefrom.

Abstract: A fluid pressure actuated piston of an aircraft multiple disc brake assembly is adapted to have an extended stroke by telescoping with a pressure actuated cylinder. The piston is slidably carried in a fluid pressure actuated cylinder which, in turn, is slidably carried in a fixed carrier. Initially, only the piston moves axially to extend its stroke with respect to the carrier. The cylinder's structure and axial position with respect to the carrier creates a fluid pressure responsive surface area initially sealed from the effects of the fluid pressure. Axial movement of the cylinder is initially resisted by either mechanical or differential pressure member until the stroke of the piston reaches a predetermined axial position to engage the cylinder. Continued extension of the piston's stroke urges the cylinder axially to break the fluid seal and expose the heretofore unaffected surface area of the cylinder to fluid pressure thereby extending the stroke of the cylinder a predetermined axial distance.

Abstract: A fluid pressure actuated piston is slidably carried in a fluid pressure actuated cylinder which, in turn, is slidably carried in a fixed carrier. Forward axial movement of the cylinder is restricted by a hydraulic pressure balance condition which is created by reducing the rearward surface area of the cylinder. The cylinder is maintained in a pressure balanced condition during the entire operation of the piston assembly. After the piston moves axially forward a predetermined distance, it engages the cylinder and urges the cyliner axially forward the same distance traveled by the piston. The piston's maximum axial movement is thereby extended by the distance the cylinder travels. The output force of the piston is substantially unaffected by the force imposed on the cylinder. Also, the cylinder does not provide any work force area.

Abstract: A fluid pressure operable servo positioner including a pair of operating piston units diametrally opposingly arranged relative to and abuttingly engageable with opposite sides of a mechanical operating member or lever for positioning the operating member in a preselected position determined by the degree of actuating pressure acting on the piston or pistons which are retractable by return springs, when relieved of actuating pressure acting thereon, completely out of contact with the operating member to an extent at which the operating member may be manually positioned, within a full range of positions, free of any resistance such as piston friction.

Abstract: A self-aligning and end fixity connector for connecting a hydraulic cylinder piston rod to its respective boom section in a multi-section telescopic boom assembly wherein the piston rod end is rigidly and fixedly secured to a structural part of one boom section. The cylinder barrel has a lost motion connection with a next adjacent boom section whereby slight movement in a vertical direction can occur between the cylinder barrel and said next adjacent boom section. The arrangement significantly increases the column loading capacity of telescoping crane boom hydraulic cylinders and reduces significantly the tendency for cylinders to bind with their piston rods due to inevitable cocking of boom sections.

Abstract: A self-aligning and end fixity connector for connecting a hydraulic cylinder piston rod to its respective section in a multi-section telescopic boom assembly wherein a pair of rectangular plates are secured to the free end of the piston rod, the plates being received in retainers secured to the boom section to thereby prevent the piston rod from rotating and thus providing end fixity to the rod. A clearance is provided between the plates and the retainers to allow a slight floating action of the rod in a vertical plane so that the rod connection point is substantially in alignment with the cylinder connection point to allow full retraction without binding of the boom sections.

Abstract: A telescopic fluid ram or thruster utilizing pressurized gas and having an inner and outer piston that slides within a cylindrical bore including a central probe which is tapered and extends into the bore of the inner piston where it will cause the inner piston to move under high pressure while the gas escaping from around the tapered area produces a holding force to hold the outer piston in place until the inner piston is fully extended, at which time the outer piston will extend under a reduced pressure.

Abstract: A fluid pressure actuated piston is slidably carried in a fluid pressure actuated cylinder which, in turn, is slidably carried in a fixed carrier. Movement of the cylinder is resisted by a deformable tube frictionally engaged with a fixed circular member. A predetermined fluid pressure acting across a differential area wall portion of the cylinder generates a force overcoming the frictional resistance of the deformable tube engaged with the fixed circular member thereby advancing the cylinder in the direction of movement of the pressurized piston. The output force of the piston is substantially unaffected by the force imposed on the cylinder.

Abstract: An extensible cylinder slidably containing a fluid pressure actuated piston is provided with differential first and second area portions exposed to a piston actuating pressurized fluid and an opposing pressurized fluid which opposing fluid is pressurized by a fluid pressure amplifier or booster responsive to the piston actuating pressurized fluid to maintain a proportional relationship between the pressures of the piston actuating fluid and opposing fluid to thereby generate a force balance on the cylinder. A stop on the cylinder is engaged by the piston upon completion of the piston stroke in the cylinder causing the cylinder to advance with the piston to thereby extend the stroke of the piston. The volumetric requirement of the piston actuating pressurized fluid for a given displacement of the piston is constant regardless of the position of the extensible cylinder.

Abstract: A master cylinder having a secondary piston for absorbing rapid initial pressure increases in proportion to the stroke of the primary piston. The master cylinder includes a housing having a first cylinder formed therein. A first piston is movable within the first cylinder. A second cylinder is formed in the first piston. A second piston is movable within the second cylinder.