Abstract: A free piston engine used for providing power augmentation to an aircraft turbine engine. The engine has a central cylinder, a central piston, fuel intake valves and exhaust ports, for exiting hot exhaust gases. The exhaust gases are used to help drive turbine blades in the turbine engine. The piston includes a piston drive shaft with opposite ends attached to first and second ported push rods The push rods are attached to first and second intake pistons. The intake pistons can include magnets mounted thereon and used to generate DC electrical current. The central power cylinder includes first and second spark plugs connected to first and second ignition coil and used for igniting the fuel received through the ported push rods and moving the central piston back and forth inside the central cylinder.

Abstract: A hydraulic feed-rate control apparatus pushes out a fluid by a main piston to a reservoir chamber via feed-rate adjustment mechanisms and flow passages and adjusts a feed rate of a reciprocating body; the adjustment mechanisms comprises first and second throttle valves arranged at front ends of a cylinder and adjusting flow rates of the fluid flowing into the flow passages; the main piston comprises an auxiliary piston integrally moving, and opening and closing the second throttle valve; and the auxiliary piston comprises an outer peripheral portion fitted in the second throttle valve and closed, a concave portion formed between a front portion and rear portion of the outer peripheral portion, a circulation hole formed in an inner peripheral portion of the auxiliary piston, rear-portion escape holes communicating the rear portion and the circulation hole, and concave-portion escape holes communicating the concave portion with the circulation hole.

Abstract: A fluid cylinder actuator assembly is provided. The assembly includes a cylinder tube and a cushion control needle assembly. The cushion control needle assembly is configured to extend into the fluid cylinder actuator assembly to control fluid that exits the cylinder tube and comprises: a threaded cushion control differential screw that selectively screws into a retainer having corresponding threads; a control needle that includes a stem selectively extendable through a bore in the retainer opposite of the cushion control differential screw; wherein the stem of the control needle is engageable with a threaded bore inside the cushion control differential screw that is complimentary to the threads formed on the stem so that rotating the threaded cushion control differential screw will selectively extend or retract the control needle back and forth; and wherein threads of the threaded cushion control differential screw is different than the threads in its threaded bore.

Abstract: A hydraulic cylinder has a tube with a first end and a section end. The hydraulic cylinder also has a piston assembly movably disposed within the tube and configured to move between the first and second ends of the tube. The hydraulic cylinder further has a valve plunger connected to the piston assembly and having an axial bore. The hydraulic cylinder additionally has a cap assembly connected to the tube to close off the first end of the tube. The cap assembly has a fluid passageway and the valve plunger is configured to progressively restrict fluid flow through the fluid passageway as the piston assembly approaches the first end of the tube.

Abstract: An engine valve actuation system includes an engine valve moveable between first and second positions, a valve actuation assembly connected to move the engine valve between the first and second positions, a fluid actuator configured to selectively modify a timing of the engine valve in moving from the second to the first position, a source of fluid, and a pair of passages in the cylinder that allow fluid to flow from the chamber to the fluid source. The fluid actuator includes a cylinder and a piston at least partly defining a chamber. The piston is slidably movable in the cylinder between a first position and a second position, and blocks at least a portion of one of the passages at an intermediate position between the second position and the first position to reduce fluid flow from the chamber when the piston moves from the second position toward the first position.

Abstract: A pressure cylinder is connected to an air pressure source through a servo valve, the servo valve is controlled as an on/off switching valve by a control section in an advancing working step of a piston rod, and at the time of backward stroke of the piston rod, an operation position of the piston rod is detected by a position detector to feedback a detection signal to the control section, the servo valve is controlled by the control section such that a deviation between the operation position and a preset stopping position is eliminated, the piston rod is stopped at an intermediate stopping position, and a state in which substantially the same pressures are supplied to pressure chambers formed on opposite sides of the piston is maintained.

Abstract: A fluid pressure cylinder wherein the configuration of a gasket groove for dividing a flow path is changed such that a first communicating passage (and a piping port), a cushion valve inserting hole (and a cushion valve control hole), etc. can be disposed to be close to or coincident with each other in the axial direction. The first communicating passage and the cushion valve inserting hole for a cushion valve are disposed to be close to or coincident with each other in the axial direction and displaced relative to each other at a predetermined angle with respect to the center line of the cylinder. The outer peripheral surface of an end cover is provided with a gasket groove having a predetermined width in the axial direction to divide the first communicating passage and the cushion valve inserting hole from each other. The gasket groove is fitted with a gasket.

Abstract: To influence the periodic stroke movement of the closing element of a valve, a control cylinder working on the closing element in the stroke direction is provided, which can be acted upon or released by a control element periodically with pressure medium. The control element is connected in the supply or discharge conduit of the pressure medium and can variably accelerate or slow its pressure formation or release and with it also the stroke movement of the closing element, at last gradually. Thus a partially or completely automatic control of compressor valves, for example, can be made possible in a simple manner.

Abstract: A double-acting pneumatic cylinder is characterised by the provision of a pair of sealing elements respectively located on either side of the piston by means of rods slidably mounted in longitudinal bores formed in the piston. At the commencement of the cylinder's in-stroke, the rod and its associated sealing element is in an extended position and serves to seal off the main exhaust port while the piston is still relatively distantly located from the end of its in-stroke. During further in-stroking the piston, air can therefore exhaust only through the auxiliary exhaust port and the motion is thus cushioned. The out-stroke of the cylinder is similarly cushioned over a relatively large distance by virtue of the sealing element adopting an extended position and closing off the main exhaust port, the air exhausting through the auxiliary exhaust port.

Abstract: Snubbers are useful in dampening inertia loads at the end of stroke movement of a hydraulic motor. Known snubbers usually have a spear type annular orifice with an associated plunger which usually restrict fluid flow in the non-snubbing mode thereby slowing response in the opposite direction. The subject snubber includes a snubber stem which is moved to contact the end of a tubular hydraulic cylinder so that all fluid from an actuating chamber must pass through a circular orifice which will build up pressure in the actuating chamber to provide a dampening effect on a piston rod assembly. When fluid is directed into the actuating chamber the snubber stem will move away from the end of the tubular hydraulic cylinder to allow free flow into the actuating chamber to provide quick response for extension of the piston rod assembly.

Abstract: A solid valve spool is split in two, by cutting through its center land diameter. A drill rod spacer is machined to length and inserted between the spool pieces to establish a spool assembly having a precise land width. The spool pieces and spacer are biased together in assembly so as to travel in unison, within a valve bushing, when shifted to control fluid flow, and the precisely-spaced land edges serve to pinch off fluid flow.

Abstract: A pneumatic cylinder includes a cushioning device having a first cushioning sleeve gradually decreasingly communicating a first cushioning chamber with a first passage formed on a first cap and connected to a first fluid flowing ports as the first cushioning sleeve is gradually inserted into the first passage; a second cushioning sleeve gradually decreasingly communicating a second cushioning chamber with a second passage formed on the second caps and connected to the second fluid flowing ports as the second cushioning sleeve is gradually inserted into the second passage; a first quick fluid exhaust valve which is mounted on the first cap and is selectively opened by pushing force of the piston to communicate the first cushioning chamber with the first passage; a second quick fluid exhaust valve which is mounted on the second cap and is selectively opened by pushing force of the piston to communicate the second cushioning chamber with the second passages; a first quick fluid supply valve which is mounted on t

Abstract: A machine tool which comprises a headstock (111) and at least one tool changer (120). The tool changer (120) shifts the production tools (116) between a magazine position and a working position, a drive unit (123) being provided for it in the form of at least one fluid power drive cylinder (1), wherein a piston is arranged for axial motion and for whose terminal fluid damping a damping device is provided. The drive cylinder (1) provided with a setting device, by means of which the terminal position damping may be switched over between at least two preset values.

Abstract: An end of stroke cushion for a linear hydraulic motor. A piston-cylinder unit includes a cylinder body (42) reciprocally slidable on a piston rod (40) having a piston head (64) which defines working chambers (82, 84) within the cylinder body (42). The piston rod (62) is tubular and includes a plurality of sidewall ports (P1-P7). A radially-expandable annular valve ring (106) normally snugly surrounds the piston rod (62) and during axial movement of the cylinder body (42) relative to the piston rod (62), the valve ring (106) will move axially relative to the sidewall ports (P1-P7) in the piston rod (62). Pressure introduction to the working chamber (84) through the sidewall ports (P1-P7) of the piston rod (62) and against the valve ring (106) radially expands the valve ring (106).

Abstract: Cylinders of the type used in fluid power systems are cushioned by a floating spear. The reciprocating piston is centrally bored to receive the spear. Accordingly, the spear and piston are movable independent of each other. A blind axial bore is formed in opposite ends of the spear and one or more diametrically extending bores are also formed in the spear in open fluid communication with those axial bores. Thus, when the spear enters the cushion cavity, the piston continues its motion and progressively blocks off the diametrically extending bores. Air in the cylinder cavity escapes into the atmosphere through the cushion cavity, but is constrained to enter the spear through one or more of the diametrically extending bores and hence through an axially extending blind bore. The length of the spear is variable, as is the length and diameter of the blind bore and the number, diameter, and spacing of the diametrically extending bores. Thus, the deceleration of the piston is programmable.

Abstract: A telescopic pneumatic hoist has a flexible stationary hollow probe on its base arranged to unseat a check ball in the piston of the lowest intermediate stage when the piston is near the base. When such a condition exists, the probe closely interfits with the piston and has a radial port communicating with the underside of the piston. The probe connects at the bottom with a supply and exhaust passage which also communicates with the underside of the piston via a check valve controlled secondary passage.

Abstract: Device and procedure for the supply, with recovery of the raising energy, of press actuators having a cylinder within which a piston delimits two chambers, namely an upper and a lower chamber, which are supplied with pneumatic power, the said device having a pneumatic control unit connected to the mains and including at least one supply line to the upper chamber of the actuator and one supply line to the lower chamber of the actuator, these lines having supply and discharge valves, in which device the supply lines to the chambers of the actuator pass through an economizer unit interposed between the control unit and the actuator and including a servocontrolled valve which intercepts the supply line to the upper chamber, a servocontrolled valve which intercepts the supply line to the lower chamber, and a connecting pipe between the supply line of the lower chamber and that of the upper chamber, downstream of the said intercepting valves, and provided with its own servocontrolled intercepting valve, while means

Abstract: An actuating device for pipe-chamber feeders of hydraulic transport equipments comprising valves or other closing appliances having a closing element that is movable reciprocally between an open and a closed position, the improvement being characterized in said closing element being associated with at least one speed control means, especially a speed reducing means acting at least at the end phase of the closing stroke of said closing element.The speed reducing effect of at least one of said speed control means may be adjustable.

Abstract: Initiation of piston movement in a fluid actuator and sustained piston movement at a controlled rate are achieved by control of servo pressure in the actuator.

Abstract: The invention provides a conduit blow out preventer utilizing movement of an annular piston to selectively effect the reduction of flow through the blowout preventer to a pre-determinable value or alternately, terminate flow therethrough altogether in response to the occurence of a pressure fluctuation in the fluid conduit to which the conduit is attached. An annular fluid conduit is defined between the interior bore of the annular piston and a support post. A discontinuous annular sealing element is provided in such fluid passage to provide an orifice, creating a pressure differential across the piston in the event of a biased flow surge. Axial movement of the annular piston results in closing of the outward fluid flow in the annular fluid passage and flow is then restricted to that permitted by a radially disposed orifice communicating with the annular fluid passage. A check valve in a fluid inlet is normally held off its seat by a connecting rod extending to the support post.

Abstract: An air cylinder has a main piston which is movable backwardly and forwardly under the control of air pressure and it is closed on at least one end with an axially extending damping bore which terminates in a closed end having a stop member adjacent this end. A vent hole connects to the interior of the cylinder to the damping bore and another vent hole connects into the cylinder main space. Each vent hole is advantageously connected to a throttle and check valve which permits inflow of air to the associated spaces and a throttled exit of the air depending on the position of the piston in the cylinder. The piston carries a damping piston in the form of a cylindrical extension thereof which is movable with the piston toward the closed end and has an open end with an axially extending damping bore therein having a check valve which closes the opening.

Abstract: A cushioning device for decelerating and stopping the piston in a hydraulic cylinder by restricting and throttling the fluid flow from the cylinder.

Abstract: Braking of the motion of a fluid-actuated drive is provided by a buffer arrangement which is normally sealed to prevent vaporization of the fluid in a buffer cylinder and which isolates the drive piston rings from braking pressures.

Abstract: A fluid jack (10) has a cushioning device (21) positioned within a cylinder (11) between a piston means (12) and a closed end (13) with the cushioning device (21) being a self-contained unit independent of any major components of the fluid jack (10). A variable volume chamber (24) is formed between a pair of members (22,23) with the cushioning taking place by metering the fluid expelled from the variable volume chamber (24) in response to the piston means (12) engaging and moving one of the members (22,23) in a direction for decreasing the volume of the variable volume chamber (24).

Abstract: The hydraulic lifting device for harvesting machines includes a hydraulic cylinder-piston unit mounted on the wheel frame of the machine and supporting most of the weight of the harvesting apparatus so that the latter abuts against the ground with residual weight only. The cylinder-piston unit is controlled by a multi-way selector valve and a locking valve unit connected in a first working pipeline system. The hydraulic device further includes a pressure limiting valve for setting a reference pressure for the hydraulic cylinder-piston unit, the limiting valve being connected in an additional working pipeline that is branched upstream the limiting valve to a nonreturn valve and therefrom is connected by a direct conduit to a hydraulic accumulator and the hydraulic cylinder-piston unit.

Abstract: An adjusting drive operated by a pressure medium with a spring-loaded roller diaphragm secured to plates and displaceable within a housing by the pressure medium; the roller diaphragm actuates an adjusting member that is securely connected with a plate and extends out of the housing; in addition to its end positions, the adjusting member is also able to assume at least one intermediate position; the plates are thereby connected with each other by the roller diaphragm while a plate not directly connected with the adjusting member sealingly rests on a ring-shaped abutment projecting out of the inner wall of the housing in the intermediate position of the adjusting member.

Abstract: The invention relates to a cushioning device for a piston of a pneumatically operable driving tool which includes a cylinder, wherein a drive piston connected to a driver blade is axially movable; including further a bumper at the lower end of the cylinder and an annular chamber connected to a fluid power reservoir; this chamber is located underneath the piston and is surrounding the driver blade. The annular chamber, created by the piston and a wall, generally parallel to the face of the piston, will be reduced in volume to a certain extent when the wall impacts on the bumper to reduce the noise generated during the driving action.

Abstract: A digitally controllable pneumatic linear actuator in which a moving piston driven by compressed air is initially decelerated by the pressure of compressed air applied to the both sides thereof in the course of its advancing movement toward a predetermined stop position and is then braked by a mechanical brake, thereby obviating failure of precise positioning of the piston due to the compressibility of air. The piston displacement is digitally detected, and the result of detection is fed back to a digital controller.

Abstract: The piston of a fluid ram is provided with an end of stroke braking means comprisng a pusher adapted to contact the end wall of the ram cylinder as the piston approaches the end wall to restrict the flow of fluid from the outlet chamber of the ram to an outlet part. As the ram moves nearer the end the pusher opens a valve in the piston to connect the inlet chamber of the ram to the outlet part.

Abstract: A fluid motor for a backhoe or the like. A hollow motor cylinder is provided with upper and lower end plates to define a motor chamber through which a generally vertical shaft extends. The shaft is journalled for relative rotation and a first vane is located within the motor chamber and is secured to the shaft and sealingly engages the cylinder and the end plates. A second vane is located within the motor chamber and is secured to the cylinder and sealingly engages the shaft. Ports of a first set are interconnected for continual fluid flow between each other and open into the chamber adjacent one side of the second vane and include at least one port in each of the end plates. Ports of a second set are interconnected to each other and open into the chamber adjacent the other side of the second vane and include at least one port in each of the end plates.