Abstract: In a cushion mechanism of a gas cylinder, when the pressure of a gas in a first pressure chamber is less than or equal to a prescribed pressure, a valve body cuts off communication between the upstream side and downstream side of a discharge flow passage by mean of the biasing force of a spring member. In addition, when the pressure of the gas exceeds the prescribed pressure, the valve body is displaced to the downstream side of the discharge flow passage against the biasing force, thereby enabling communication between the upstream side and the downstream side of the discharge flow passage.

Abstract: An adjustment device for a splicing display screen includes: a housing including housing walls and an accommodating cavity, the housing walls including first, second, third and fourth housing walls; a piston member including a piston and a piston rod, wherein the piston is slidably connected in the accommodating cavity, a through hole is provided in the fourth housing wall, and the piston rod is slidably connected in the through hole; an elastic pressing portion in the first housing wall, serving as a part of the first housing wall; and a hydraulic sensor in the accommodating cavity. The accommodating cavity is filled with hydraulic fluid, an inner surface of the elastic pressing portion contacts the hydraulic fluid, and the piston member is configured to be driven by the hydraulic fluid to move in an extending direction of the through hole in response to a pressure applied on the elastic pressing portion.

Abstract: A pneumatic cylinder includes a cylinder body, a piston assembly, a connecting rod, and at least one pressure-relief valve. The cylinder body is formed with a cylinder chamber, and has an exterior disposed with at least one inlet-outlet passage and at least one pressure-relief opening, wherein the inlet-outlet passage is connected to the cylinder chamber. The piston assembly is contained within the cylinder chamber. The connecting rod is connected to the piston assembly, and protrudes out from the cylinder body. The pressure-relief valve is disposed in the pressure-relief opening, and has two ends connected to an outside of the pneumatic cylinder and the cylinder chamber respectively. When a gas pressure within the cylinder chamber is greater than a threshold value, the pressure-relief valve works to allow the cylinder chamber connecting to the outside for pressure relief.

Abstract: Some embodiments of a gearbox for an irrigation system can comprise a housing, a worm gear within the housing, a bull gear within the housing and configured to be engaged with the worm gear, a diaphragm, and a vent. The diaphragm can define a chamber configured for expansion and contraction and configured to be positioned inside the housing to relieve pressure build-up within the housing. The vent can be configured to allow air to flow between the atmosphere and the chamber.

Abstract: Methods and apparatus for position sensitive dampening. In one aspect a fluid damper is provided comprising a damper chamber divided by a piston into a primary compression and a primary rebound chamber; a secondary compression chamber in fluid communication with the damper chamber; and an adjustable fluid meter controlling fluid flow out of the secondary compression chamber.

Abstract: A fluid operated actuator (100) is provided. The fluid operated actuator (100) includes a body (101) forming a piston bore (201). A piston (111) is movable within the piston bore (201). The fluid operated actuator (100) also includes a valve unit (105) coupled to the body (101) and including a fluid inlet port (217), a fluid exhaust port (220), and a valve member (214) configured to selectively open a fluid flow path between the fluid inlet port (217) and the piston bore (201) and between the exhaust port (220) and the piston bore (201). The fluid operated actuator (100) can also include a control unit (106) coupled to the body (101) and the valve unit (105). The control unit (106) can include a pilot input port (317a) in fluid communication with the fluid inlet port (217). The control unit (106) can also include first and second pilot output ports (317b, 317c) in fluid communication with the valve member (214).

Abstract: Examples of a pressure wave generator configured to generate high energy pressure waves in a medium are disclosed. The pressure wave generator can include a movable piston with a guide through which a piston control rod can move or slide. The pressure wave generator can include a transducer coupled to a medium. During an impact of the piston on the transducer, the control rod can slide in the guide, which can reduce stress on the rod. The pressure wave generator can include a damper to decelerate the control rod, independently of the piston. Impact of the piston on the transducer transfers a portion of the piston's kinetic energy into the medium thereby generating pressure waves in the medium. A piston driving system may be used to provide precise and controlled launching or movement of the piston. Examples of methods of operating the pressure wave generator are disclosed.

Abstract: A self-adjusting end position damping arrangement includes a stroke space 9 which is delimited by a movable stroke element 7, 24 and a part of the pneumatic cylinder 1, with the stroke space 9 being connected via a connecting duct 14 to the working pressure P1 which acts on the cylinder piston 22 or to the ventilation pressure (P3) in the outlet duct 3 and the stroke element 7, 24 being acted on via a damping duct 16 by the damping pressure P2 in the damping volume 19, a non-return valve 12 is arranged in the connecting duct 14 upstream of the stroke space 9, which non-return valve 12 blocks in the direction of the working pressure P1 or the ventilation pressure (P3), respectively, and a ventilation duct 5 is provided, which ventilation duct 5 can be opened by means of the movable stroke element 7, 24 and which is connected to an outlet duct 3.

Abstract: A hydraulic actuator comprising a hollow body (1, 3) defining a cylindrical cavity and a rod (5) which is mounted to slide within the body along a sliding axis between two end positions and which is integral with a piston sliding in a sealed manner within the cylindrical cavity in order to define two chambers (C1, C2). The rod defines an interior passage, connecting the two chambers, which has a valve (20) comprising a shut-off member (21) which is returned towards a seat (22) and closes the passage. The rod receives a push member (15, 26) which can move relative to the rod between a position apart from the shut-off member (21) and a position forcing the shut-off member to open. The push member is constrained, when the rod reaches the end of its stroke, by the push member engaging with a portion (3) of the hollow body.

Abstract: A fluid operated linear drive in which on the outer periphery of a centering portion (24) fitting in a housing tube (4) at least one housing cover (5) has an annular groove (28) accommodating an annular seal (32). The outer flank (36), which is on the side of the housing tube (3), of the annular groove (28) is a component of cap part (42), which is coaxially mounted on the centering portion (24) and fixed on the housing cover (5). This division into two parts facilitates production of a flash-free annular groove (28) without fettling.

Abstract: A gasket includes a damping buffer for a piston that can be charged with a pressure medium and that can be moved back and forth axially in a cylinder pipe and includes at least one static seal for sealing the cylinder pipe vis-à-vis a cover connected to the face of the cylinder pipe and a dynamic seal having at least one dynamically loaded sealing lip that, during the proper use of the gasket, can be laid against the surface to be sealed of a damping journal that is connected to and axially movable back and forth with the piston and that has at least one flow-guiding connection opening that connects the axial faces of the gasket.

Abstract: A cushion ring which is used between a rod-side cylinder head and a piston rod of a fluid-pressure cylinder and which is externally fitted on the piston rod to cushion a shock in the vicinity of the farthest extended end of cylinder includes a throttling groove that has a V-shaped cross section. The throttling groove extends from an appropriate position of the cushion ring to a rod-side end part and functions to throttle the flow of a working fluid flowing from a rod-side fluid chamber to an input/output port provided in a rod-side cylinder head. The throttling groove is provided at the outer periphery of the cushion ring. The throttling groove terminates at a rod-side end part with an end guide face that guides the working fluid toward a slantwise outward direction of the cushion ring.

Abstract: A gasket includes a damping buffer (1) for a piston (2) that can be charged with a pressure medium and that can be moved back and forth axially in a cylinder pipe (3) and includes at least one static seal (4) for sealing the cylinder pipe (3) vis-à-vis a cover (5) connected to the face of the cylinder pipe (3) and a dynamic seal (6) having at least one dynamically loaded sealing lip (7) that, during the proper use of the gasket, can be laid against the surface (8) to be sealed of a damping journal (9) that is connected to and axially movable back and forth with the piston (2) and that has at least one flow-guiding connection opening (10) that connects the axial faces (11, 12) of the gasket.

Abstract: First and second cushion rings are arranged respectively on both end surfaces of a piston constituting part of a fluid pressure cylinder, through fitting grooves. The first and second cushion rings are formed with substantially hollow cylindrical shapes by press working a metal material, wherein the cushion rings effectuate a cushioning action, which decelerates the displacement speed of the piston, as a result of being displaced in the axial direction together with the piston and being received and accommodated within a recess of the head cover and a rod hole of the rod cover.

Abstract: A pallet positioner includes a support frame that consists of a main upright structure with a pair of spaced, parallel outriggers extending horizontally at ground level. The distal ends of the outriggers are connected by a low-profile ramp. The upright structure includes a pair of vertical guide masts rigidly mounted on a horizontal base bracing the proximal ends of the outriggers. A pneumatically and hydraulically controlled, or electrically and hydraulically controlled, cantilevered carrier with a rotatable platform is mounted for vertical motion along the vertical guide masts. When the carrier travels downward, the carrier stops automatically at a level above the outriggers and must be manually restarted. A braking system under the platform prevents rotation thereof at ground level.

Abstract: A cylindrically shaped valve rod is housed in a valve hole formed in a cylinder body in a manner so as to be rotatable around a center axis line, and a connecting hole having a first hole opening that is allowed to communicate with a first flow path hole, and a second hole opening that is allowed to communicate with a second flow path hole is formed in the valve rod. A flow adjusting groove that is extending in a circumferential direction around an outer periphery of the valve rod from a position of the first hole opening is formed, and the flow adjusting groove is formed such that a groove width gradually narrows toward a tip end side and the groove depth gradually shallows at the same time, so that the valve opening extent is adjusted along with rotating operation of the valve rod.

Abstract: A plunger-cylinder assembly for a press including a plunger which is accommodated at least in part in a cylinder while separating the interior of the cylinder into two partial chambers along the cylinder axis. A relieving device which counteracts an increase in pressure of a fluid accommodated in the first partial chamber is disposed in at least one first partial chamber the increase in pressure being caused by a movement of the plunger along the cylinder axis in the direction of the first partial chamber. A hydraulic press encompassing such a plunger-cylinder assembly is also described.

Abstract: A hydraulic piston pump in which a cylinder port (4b) can be communicated with a discharge port (9) after a system pressure (Po) and a chamber pressure (Pi) in a cylinder bore are in an equilibrium state. A through-hole (16) opened in that surface of a valve plate (7) on which a cylinder block (3) slides is communicated with one end surface (21a) side of a balance valve (20), and the system pressure (Po) on the discharge port (9) side is supplied to the other end surface (21b) of the balance valve. A balance piston (21) is built-in in the balance valve, and the balance piston (21) slides by a pressure difference between the chamber pressure (Pi) in the cylinder bore (4) and the system pressure (Po). Before a cylinder port (4b) is communicated with an oil guiding groove (15), the chamber pressure (Pi) and the system pressure (Po) can be brought into an equilibrium state by actuation of the balance piston (21).

Abstract: A mower including a hitching structure configured to be connected to a motor vehicle, a cutting mechanism, a maneuvering device configured to bring the cutting mechanism from a working position to a maneuvering position, and a lightening device configured to transfer a part of the weight of the cutting mechanism onto the hitching structure, the lightening device including a hydraulic cylinder.

Abstract: A fluid actuator with fluid limit valves (550, 551) and optional adjustable mechanical limits enables the construction of fluid linkages which are able to completely replace mechanical linkages. In a fluid circuit comprising of two or more fluid actuators, the pistons (102) of the fluid actuators can become uncorrelated when fluid leakage occurs. At the piston (102) extension and retraction limits, fluid limit valves (550, 551) open. The open fluid limit valves (550, 551) allow fluid to bypass pistons (102) and/or allow fluid from an external source to compensate the fluid leakage. The fluid bypassing pistons (102) at their extension or retraction limit and/or externally supplied fluid forces the uncorrelated pistons (102) to reach their extension or retraction limit as well. The fluid actuator with optional adjustable mechanical limits have one or more additional pistons (686, 688), which have an adjustable separation from the main piston (102) or end of cylinder.

Abstract: A hydraulic cylinder comprising a cylinder, a piston which is adjustable in the cylinder, and at least one pressure connection which is disposed in the vicinity of an end position of the piston and through which a pressure fluid can be introduced into the cylinder, is characterized in that the piston is provided with a valve element which can cooperate with the pressure connection, in order to cover the pressure connection when the piston approaches its end position, and in order to uncover the pressure connection when pressure fluid is introduced into the cylinder.

Abstract: The piston of a fluid motor divides the cylinder into two variable volumes into which and from which fluid may be selectively introduced and exhausted via ports through the cylinder to relatively move the piston and the cylinder. The piston is modified to define two fixed-volume chambers that respectively communicate with the variable volumes via restrictive orifices. In selected relative piston-cylinder positions, the chambers communicate with the ports to restrict fluid flow into and out of the variable volumes and to decrease the velocity of relative piston-cylinder movement. In other relative piston-cylinder positions, the chambers do not communicate with the ports and fluid enters and leaves the variable volumes directly through the ports to relatively move the piston-cylinder at a higher velocity.

Abstract: A pair of throttle valves are installed to first and second installation holes of a cylinder tube, respectively. The throttle valve comprises a rotatable member, a needle which is engaged with the rotatable member and which controls the flow rate of a pressure fluid flowing through first and second bypass passages formed in each of the first and second installation holes, a covering member which covers each of said first and second installation holes, and a stopper ring which prevents the displacement of the rotatable member.

Abstract: The powered pipe cutter and the pipe flaring tool both have a piston slidably mounted in a cylinder. The cylinder has a top end closed by a top end plug. A crimped cartridge bore in the top end plug communicates with a gas expansion chamber. A bolt and firing pin assembly are attached to the cylinder top end. The pipe cutter includes a shear housing with a pipe passage connected to the rod end of the cylinder. A shear plate is connected to the piston and moves with the piston to shear pipes. The pipe flaring tool includes a pipe clamp assembly with a pipe passage and a female flaring surface connected to the cylinder rod end. A male flaring surface on the piston cooperates with the female flaring surface to flare pipe ends.

Abstract: A pressurized medium activated working cylinder with a piston that can move longitudinally in a cylinder chamber between two end positions has a device for damping the movement of the piston when it approaches each end position. This device comprises, e.g., a damping pin arranged at the cylinder cover, which is inserted into a corresponding receptacle opening in the piston when the piston approaches the end position. The damping pin and the receptacle opening are arranged eccentric to a side of the piston rod, wherein the receptacle opening opens into a part projecting into the cylinder chamber.

Abstract: The present invention relates to a hydraulic dampening system which has particular utility with power tools. The hydraulic dampening system includes a cylinder and a piston positioned within and movable through a stroke. The piston has a retract face which forms a first chamber with a first end wall of the cylinder and a face opposed to the retract face which forms a second chamber with a second end wall of the cylinder. The hydraulic dampening system also includes at least one port and/or at least one gap for dampening movement of the piston during its stroke.

Abstract: A cushioned hydraulic cylinder which includes a check valve in the cushioning path to allow fast opposite direction movement. The check valve is in the form of a cast iron piston ring located within a groove in the piston which blocks unrestricted flow across the piston when the piston ring is seated against one side face of the groove and opens unrestricted flow when the piston ring abuts the opposite side face of the groove when the piston is moving in the opposite direction.

Abstract: A reciprocating compressor includes a linear motor having a piston reciprocating inside a cylinder. A cylinder head is provided with suction and discharge orifices. A valve means is mounted inside the cylinder and has an operative position, seated against the discharge orifice. The operative position is defined when the top of the piston is within a certain distance from the cylinder head. The distance is defined, so that, at the end of the compression stroke of the piston, a determined pressure is reached inside the cylinder, and the pressure results in a force on the piston. The force is opposite to a force which is impelling the piston and which is sufficient to interrupt its compression stroke before impacting the cylinder head.

Abstract: A piston stroke limiting device for a reciprocating compressor of the type including a piston (2) reciprocating inside a cylinder (3), which is closed by a cylinder head (4) and defines, between the latter and the top of the piston (2), a compression chamber (5), said device comprising: a driving element (40) provided in one of the parts defined by the piston (2) and the cylinder head (4) and projecting to the inside of the compression chamber (5), in order to touch the other of said parts when the piston (2) surpasses a predetermined nominal position at the end of the compression stroke; and a relief valve (60), which is selectively displaced from a closed condition, in which it is seated on a respective valve seat (51) defined in a relief passage (50) communicating the compression chamber (5) with a region of the compressor subject to a substantially lower operational pressure, to an open condition, by action of the driving element (40), when the piston (2) surpasses said predetermined nominal position at t

Abstract: A rack and a pinion respectively have stoppers constituted by a flat surface in both sides of tooth portions thereof. The stopper of the pinion is brought into contact with the stopper of the rack at both oscillating stroke ends of the rack, whereby a backlash is absorbed.

Abstract: An air-seal structure for pneumatic nailers includes a valve member movably engaged with the end cap of the nailer and a plurality of paths defined radially through a skirt portion of the valve member. The paths are in communication with air release passage defined in the end cap. A seal is mounted to the skirt portion of the valve member and closes the paths. The seal contacts an end of the cylinder when the trigger is not squeezed. The seal is sucked due to the difference of pressure so that it will not be loosened during movement of the valve member. A cushion member is connected to a disk member on the inside of the end cap so as to absorb shocks when the piston returns back to the ready position.

Abstract: The pneumatic cylinder includes a tubular body defining a piston chamber for a piston member, closed by front and rear heads; each head is provided with an inlet-outlet port for pressurised air, which opens out towards an annular slot coaxially arranged and communicating with the piston chamber. The piston is provided with a rod which extends through a guide bush in the front head. A pneumatic cushion is provided to control the movement of the piston at the ends of its stroke; the cushion of the front head includes a narrow passage for venting the air, and a sleeve protruding from the piston, to penetrate into an annular slot disposed coaxially around the guide bush for the piston rod.

Abstract: A pneumatic cylinder having a cylinder tube with at least one open end coupled to an end cap to close the open end. The pneumatic cylinder includes a piston reciprocally movable in the cylinder and the piston has a first seal to create a substantially fluid-tight seal with the internal surface of the cylinder tube. The piston has a piston spear at the end portion thereof for cooperating with a piston spear receiving space in the end cap. A second seal is provided in the piston spear receiving space for creating a substantially fluid-tight seal between the piston spear and the piston spear receiving space thereby creating a volume chamber between the first and second seals. The volume chamber provides a compressible volume of volume which acts as an air cushion at the end of the piston stroke.

Abstract: A cushion ring 26 enters the inner circumference of a cushion seal 34 near the end of a piston stroke, the cushion seal 34 being free to displace by a certain amount in the axial direction of a piston rod 23 in a cylinder head 28, and exerts a cushion effect by restricting oil flow from an oil chamber 24 in a cylinder tube 21. A spacer 35 is disposed on the inner side of this cushion seal 34 in the axial direction, and is free to displace by the same amount as the cushion seal 34. When the cushion effect is produced, the spacer 35 comes in contact with the cushion seal 34 to interfere with the vibration of the cushion seal 34.

Abstract: A rotary actuator has a cushion mechanism for stopping a vane at a rotational terminal end position in a cushioning manner. The cushion mechanism has first and second openings. The first opening discharges an exhaust air pressed out from a cylinder hole by a rotating vane to an external portion without limiting a flow amount. The second opening discharges the exhaust air to the external portion in a state of limiting a flow amount. A flow amount adjusting mechanism connects to the second opening. The first opening is provided at a position sealed by the vane before the vane of a hole surface in the cylinder hole reaches a rotational terminal end position. The second opening is provided at a position which is not sealed by the vane after the vane reaches the rotational terminal end position.

Abstract: A pneumatic cylinder having a cylinder tube with at least one open end coupled to an end cap to close the open end. The pneumatic cylinder includes a piston reciprocally movable in the cylinder and the piston has a first seal to create a substantially fluid-tight seal with the internal surface of the cylinder tube. The piston has a piston spear at the end portion thereof for cooperating with a piston spear receiving space in the end cap. A second seal is provided in the piston spear receiving space for creating a substantially fluid-tight seal between the piston spear and the piston spear receiving space thereby creating a volume chamber between the first and second seals. The volume chamber provides a compressible volume of volume which acts as an air cushion at the end of the piston stroke.

Abstract: The invention provides a rotary actuator having a rack driven in an oscillating manner by an air pressure, a pinion engaged with the rack, and a cushion mechanism for stopping the rack to at least one normal or inverse stroke end in a cushioning manner. The cushion mechanism has an exhaust port open to a pressure chamber at a position close to a chamber end rather than a port hole, a flow amount adjusting mechanism for restricting a flow amount of the exhaust air discharged from the exhaust port, and a cushion packing mounted to an outer peripheral surface of the piston and operating so as to shut the port hole from the pressure chamber immediately before the piston reaches the stroke end, thereby discharging the air within the pressure chamber through the flow amount adjusting mechanism.

Abstract: An output shaft is connected to a piston rod of a fluid pressure-driven linear cylinder through a converting mechanism for converting linear thrust of the piston rod into rotational torque and converting operation of the converting mechanism is controlled by operation setting means having a cam groove and a cam follower to thereby causing the output shaft to carry out linear motion and swinging rotation. A driving speed of the piston can be changed by adjusting fluid pressure acting on the piston in a linear motion area and a swinging area of the output shaft respectively.

Abstract: A piston and cylinder assembly is described having a piston which partially defines a fluid chamber in the cylinder from which fluid is expelled through an outlet port of the cylinder by movement of the piston along the cylinder, the assembly including a flow restrictor providing a first restricted flow path between the chamber and port, and also providing an auxiliary restricted flow path of which a first portion communicates with the chamber and of which a second portion extends between the first portion and the port.

Abstract: The pneumatic cylinder comprises a tubular body defining a piston chamber for a piston member, closed by front and rear heads; each head is provided with an inlet-outlet port for pressurised air, which opens out towards an annular slot coaxially arranged and communicating with the piston chamber. The piston is provided with a rod which extends through a guide bush in the front head. Pneumatic cushioning means are provided to control the movement of the piston at the ends of its stroke; the cushioning means of the front head comprise a narrow passage for venting the air, and a sleeve protruding from the piston, to penetrate into an annular slot disposed coaxially around the guide bush for the piston rod.

Abstract: In a linear actuator in which a slide table on a pedestal is caused to reciprocate linearly by two air cylinder mechanisms mounted in the pedestal, exhaust holes are provided to positions adjacent to ports, flow rate restricting mechanisms for restricting a flow rate of exhaust are provided between the exhaust holes and the ports, and pieces of cushion packing for being positioned over one of through holes of the ports on an exhaust side immediately before the piston reaches a stroke end is provided to an outer peripheral face of the piston to cause compressed air in pressure chambers to be discharged from the exhaust hole through the flow rate restricting mechanism.

Abstract: The invention provides a rotary actuator having a rack driven in an oscillating manner by an air pressure, a pinion engaged with the rack, and a cushion mechanism for stopping the rack to at least one normal or inverse stroke end in a cushioning manner. The cushion mechanism has an exhaust port open to a pressure chamber at a position close to a chamber end rather than a port hole, a flow amount adjusting mechanism for restricting a flow amount of the exhaust air discharged from the exhaust port, and a cushion packing mounted to an outer peripheral surface of the piston and operating so as to shut the port hole from the pressure chamber immediately before the piston reaches the stroke end, thereby discharging the air within the pressure chamber through the flow amount adjusting mechanism.

Abstract: A fluid-operated actuator (10) particularly for use in diesel-engined vehicles has a housing (12) defining a cylinder (14) having a cylinder wall (16) extending about a longitudinal axis (18). A piston (20) is arranged for reciprocal motion in the cylinder between a first end position and a second end position and an actuator rod (24) cooperates with the piston. The housing (12) includes first sealing means (28) for establishing a sealing contact with a first region (30) of the piston in the first end position and second sealing means (34) for establishing a sealing contact with a second region (36) of the piston in the second end position to thereby prevent leakage of operating fluid past the piston when the piston is in either of its end positions. To obviate e.g. the need for piston rings, the piston (20) and the housing (12) are arranged such that when the piston is between the first end position and the second end position, operating fluid is permitted to leak between the piston and cylinder wall (16).

Abstract: A fluid pressure cylinder (1) includes two cylinder end walls (6',6"), a cylinder tube (2) and a piston (3), which is axially movable inside the cylinder tube, wherein at least one of the cylinder end walls is provided with an outward housing portion (7;60) and, located therein, an inward insert portion (8;61) which comprises a portion of at least one fluid channel belonging to the cylinder. The cylinder is distinguished in that the housing portion axially contacts the cylinder tube under force transmission, and that the insert portion includes an integral valve seat (12,16,22") of a fluid valve which is located in said fluid channel.

Abstract: A rodless pneumatic cylinder includes main exhaust ports defined by the open ends of a pair of fixed tubular members that extend, respectively, into the cylinder body from its opposed ends. The main piston of the rodless cylinder has an axial bore formed in it in which is slidably mounted a small piston that serves mutually to isolate the working chambers of the cylinder. The bore carries seals adjacent to its opposed ends whereby, during motion of the piston, the bore sealingly receives one or other of the tubular members at a predetermined stage during the motion thereby effectively closing the main exhaust port. During further motion of the piston, air can, therefore, exhaust only through a throttled auxiliary exhaust port and such further motion of the piston is thus cushioned. The arrangement provides for a greater extent of cushioning relative to known arrangements in which the working chambers are mutually isolated by a barrier fixedly secured in the bore.

Abstract: A slidably attachable, automated means for opening and closing the die halves of a casting machine. Cylinders are provided having integral vertical side grooves for mounting on said casting machines and the like. The preferred hydraulic cylinder has a hollow piston rod connected to the piston and projecting from one end of the cylinder. A fluid flow line movable within the cylinder projects from the other end of the cylinder and slidably passes through the piston into the piston rod. Separate elements contact the piston at opposite ends of its stroke to move the fluid flow line and switch the fluid flow in the cylinder.

Abstract: In a device for stroke end cushioning and speed regulating the movement of a piston (3) in a fluid pressure cylinder (1,2) a common adjusting means (9) is arranged for simultaneous setting of the throttle means (7,8) for regulating the stroke end cushioning as well as the piston speed, for the purpose of avoiding very time consuming adjustment. In connection with the setting of the adjusting means (9) the ratio between the flow areas of the respective throttle means is held within the range of 10-60%. In the most uncomplicated embodiment the common adjusting means (9) may be comprised by a screw being fixed to the valve bodies of the respective throttle means.

Abstract: A housing has a pilot bore with an electrically controlled pilot valve therein, an intermediate bore with an intermediate valve therein, and an engine bore with a main valve therein, each valve being reciprocable between first and second stable positions. When said pilot valve is switched to its first stable position, high pressure hydraulic fluid drives said intermediate valve to its first stable position and releases said engine valve from its second stable position, whereupon a double acting spring drives the engine valve toward its first stable position. High pressure hydraulic fluid completes this movement then holds the main valve in its first stable position against the force of the double acting spring. Switching the pilot valve to its second stable position effects movement of the other valves back to their second stable positions.

Abstract: Miniature engine operated by an expanding gaseous fluid, which comprises a cylinder (18), piston (20) and inlet valve (29), the upper part of the piston (20) cooperating with a radially expansible resilient diaphragm (28), which is secured to the piston (20) and performs momentarily a pneumatic seal-engagement function along the periphery of said cylinder (18) during the gaseous expansion phase.

Abstract: A differential hydraulic jack with a damping system for the control of electric circuit-breakers is provided with a floating ring which produces a damping action at the end of travel and is also provided with a damping extension stud which forms part of the jack piston and penetrates into the damping ring. No provision is made on the jack piston for any packing ring forming a seal with the jack cylinder. The damping ring carries two projecting lips constituting a double valve which forms a leak-tight seal with the bottom face of the jack piston and the internal face of the cylinder end. At the end of the travel of the piston, the damping ring forms a double sealing valve for shutting-off the supply/drain orifice of the jack.