Abstract: To make it possible to control supply, discharge, and recycled flow rates independently of each other for the stick cylinder in a construction machine comprising first and second stick spool valves respectively connected to first and second hydraulic pumps.

Abstract: An oil control valve for a cam phaser of an internal combustion engine, the oil control valve including a valve housing, including a first operating connection, a second operating connection, a supply connection, and a tank drain connection configured to drain a hydraulic fluid; a piston assembly, including a piston, a hollow check valve tube, a first check valve and a second check valve configured to provide cam torque recirculation, wherein the piston assembly is arranged in the housing axially displaceable by an actuator, wherein a control chamber is arranged within the piston between the first check valve and the second check valve and wherein a check valve compression spring which closes the first check valve and the second check valve is arranged within the piston between the first check valve and the second check valve.

Abstract: Method for controlling continuum robots and systems therefrom are provided. In the system and method, a new system of equations is provided for controlling a shape of the elastic member and a tension on a tendon applying a force to an elastic member of the robot. The system of equations can be used to estimate a resulting shape of the elastic member from the tension applied to the tendon. The system of equations can also be used to estimate a necessary tension for the tendon to achieve a target shape.

Abstract: Provided is an apparatus to lower a load, comprising a hydraulic pump, a hydraulic actuator having first and second ports, a manipulation device, a hydraulic circuit including meter-in and meter-out flow passages for the first and second ports respectively and a regeneration flow passage with a check valve, a control valve, a meter-out flow controller adjusting a meter-out flow rate according to the manipulation device, a back pressure valve, and a non-regeneration operation relief valve whose set pressure is not less than a sum of a minimum set pressure of the back pressure valve, an inlet-outlet pressure difference of the meter-out flow controller when the meter-out flow rate is maximum and a discharge flow rate of the hydraulic pump is maximum, and an actuator pressure difference for driving the hydraulic actuator with no load, and not less than a maximum set pressure of the back pressure valve.

Abstract: Provided is an apparatus provided in a working machine to lower a load, comprising a hydraulic pump, a hydraulic actuator, a manipulation device having a manipulation member, a meter-in flow control device, a meter-out flow control device, a back pressure valve, a regeneration fluid passage branched from the meter-out fluid passage at a position upstream of the back pressure valve and merged with the meter-in fluid passage, and a check valve. The meter-in flow control device controls a meter-in flow rate in a region of the meter-in fluid passage upstream of a merging point with the regeneration fluid passage. The meter-out flow control device controls a meter-out flow rate in a region of the meter-out fluid passage upstream of a branching point of the regeneration fluid passage so as to make the meter-out flow rate be greater than the meter-in flow rate.

Abstract: A conveyor assembly for transporting tubular onto a drilling rig includes a plurality of conveyor sections coupled together end to end. The conveyor sections are configured to receive and transport the tubular. Each of the plurality of conveyor sections includes a conveyor belt having treads for transporting the tubular along the conveyor section. The conveyor assembly also includes an actuation assembly configured to transition the plurality of conveyor sections between a first orientation and a second orientation. The conveyor sections are not aligned in the first orientation, and the conveyor sections are substantially aligned in the second orientation.

Abstract: A pneumatic motor includes a housing, a rotor, an air flowing unit and an air-supply unit. The housing has an inside space formed along an axis and divided sequentially into a rotor chamber, a valve chamber and an inlet chamber. The rotor is rotatably mounted in the rotor chamber. The pneumatic valve is mounted in the rotor chamber and the valve chamber and includes an air flowing unit and an adjusting gate. The air-supply unit is mounted in the inlet chamber and is connected to a source of compressed air, so the compressed air can flow from the inlet chamber into the valve chamber and then flow through the pneumatic valve to drive the rotor.

Abstract: A vacuum brake booster includes a housing in which a piston is accommodated, the piston being supported by a cylindrical body sealingly passing through an opening in the bottom and having a key that engages with the return element of the cylindrical recess. A damping element separates the front of the key from the rear of the base supporting the piston and the bead of the membrane.

Abstract: The landing gear systems, methods and apparatuses disclosed herein may comprise a shrink pump and a shrink valve that are capable of shrinking a landing gear by up to 40% of its available stroke, or more depending on the air spring configuration. The shrink pump may be configured to pump fluid (e.g., a hydraulic fluid) between an oil chamber, where hydraulic fluid is likely present and a shrink chamber to shrink the landing gear. Moreover, the shrink pump and shrink valve may be part of a strut shrink system.

Abstract: Valve control device includes a body with a longitudinal axis, a control member housed at least partially in the body in a bottom portion along the longitudinal axis, a piston movable along the longitudinal axis and housed in a portion of the body forming with the piston a control chamber of the piston, an element movable in rotation with respect to the longitudinal axis on a top portion of the body, and sealing means between the movable element and the control chamber in the area of the connection port and/or of the passage.

Abstract: Embodiments of a directional valve assembly that provides a single device with functionality of a two-position design for automated operation and functionality of a three-position design for manual operation. The embodiments can include a housing with a piston chamber and a spool member that transits in the housing to regulate the flow of a working fluid to a cylinder. The embodiments can also have one or more pilot operators that regulate the flow of pilot air into the piston chamber to move the spool member between two positions, i.e., two open positions. The embodiments can also have a manual operator (e.g., a lever) that can move the spool to the open positions and to a closed position. In one embodiment, the spool member is configured to remain in either a first position, a second position, or a third position in the absence of an outside stimulus on the pilot operators.

Abstract: A device includes an actuation system with a dose chamber including an inlet for high pressure fluid. A working chamber extends away from the dose chamber. An annular wall separates a portion of the working chamber from the dose chamber such that the dose chamber encompasses the portion of the working chamber. In use an item to be driven along the working chamber is at least partially within the surrounded portion of the working chamber with the item at one end of its travel in the working chamber. A valve mechanism selectively allows high pressure fluid from the dose chamber to flow into the piston chamber.

Abstract: An engine includes cylinders using pressure differences to motivate the pistons. Each cylinder has a first outlet in its' first end, the first outlet being coupled to a vacuum chamber via a first valve and a first conduit, a second outlet in the cylinder's first end, the second outlet being coupled to an air pressure chamber via a second valve and a second conduit, a third outlet in the cylinder's second end, the third outlet being coupled to the vacuum chamber via a third valve and a third conduit, and a fourth outlet in the cylinder's second end, the fourth outlet being coupled to the air pressure chamber via a fourth valve and a fourth conduit. The valves are electrically controlled by a processor. When the first and fourth valves are turned on, the piston is pulled forward by a pressure difference created by the vacuum chamber and is at the same time pushed forward by a pressure difference created by the air pressure chamber.

Abstract: A central valve for a pivot motor actuator, the central valve including a housing tube including a first operating connection, a supply connection, a second operating connection and a tank drain connection; a piston enveloped by the housing tube and moveable relative to the housing tube, wherein the first operating connection is connected with the supply connection and the second operating connection is connected with the tank drain connection in a first position of the piston, wherein the piston is positioned in a center position in a second position, and wherein the second operating connection is connected with the supply connection and the first operating connection is connected with the tank drain connection in a third position of the piston, wherein the piston includes at least one first check valve on its outside.

Abstract: A plunger pump or plunger motor includes a block accommodating a first cylindrical chamber and a plunger movable in this chamber and a drive shaft connected to this plunger, as well as a second cylindrical chamber and a control valve movable in this second cylindrical chamber. Holes O3 and O4 can alternately be brought into communication with the connection for the delivery pipe by the plunger and with a connecting hole for a pressure line. The control valve can establish a communication between the hole O2 and the connecting hole. The drive shaft is connected to a further plunger which is movable in a third cylindrical chamber in which there is a suction hole or delivery hole. The control valve can alternately establish a communication between the suction hole or delivery hole with a connecting hole for a suction pipe and the connecting hole for the pressure line.

Abstract: A hydraulic cylinder is provided. The hydraulic cylinder includes a casing with a longitudinal axis defined therethrough, a first fluid inlet defined in the casing, a second fluid inlet defined in the casing, a first fluid outlet defined in the casing, a second fluid outlet defined in the casing, a shaft extending along the longitudinal axis, a first switching valve mounted to the shaft, a second switching valve mounted to the shaft, and a piston mounted to the shaft between the first switching valve and the second switching valve, wherein the hydraulic cylinder is configured such that when a fluid is supplied to the first and second fluid inlets, the shaft, the first and second switching valves, and the piston oscillate back and forth along the longitudinal axis.

Abstract: A void protection system for a mining shovel having an operator input device includes an independent metering valve assembly including one or more fluid source-cylinder valves for fluidly connecting the fluid source to the hydraulic cylinder. The system also includes a sensor assembly for monitoring the fluid pressure within the rod end and the head end of the hydraulic cylinder, and a control module. The control module is configured to monitor movement of the operator input device, monitor pressure within the hydraulic cylinder, increase the opening of the corresponding fluid source-cylinder valve and increase fluid flow from the fluid source to fill corresponding end of the hydraulic cylinder until pressure in the corresponding end of the hydraulic cylinder is above a first threshold pressure.

Abstract: A hydraulic system for a work machine may include a first hydraulic cylinder, a second hydraulic cylinder and a monospool assembly in fluid communication with the first hydraulic cylinder and the second hydraulic cylinder. The monospool assembly may facilitate at least one of a cylinder-to-cylinder regeneration flow, makeup flow and supplemental flow to at least one of the first hydraulic cylinder and the second hydraulic cylinder.

Abstract: An actuation system for a joint includes an actuator having a piston, an articulating element coupled to the actuator that is driven by the piston to match a gait cycle of an appendage, an energy source engaged with the piston that energizes working fluid within the actuator to drive the piston and generate exhaust gas, a plurality of valves coupled to the actuator, and an exhaust gas holding element coupled to the actuator that is sized to hold a volume of the exhaust gas contained within the actuator.

Abstract: An air engine includes a cylinder, a piston, a gas supply and an intake-exhaust mechanism. The gas supply supplies a compressed gas to move the piston reciprocating in the cylinder. The intake-exhaust mechanism connected to the cylinder and the gas supply includes a body and an intake-exhaust assembly. The body has a chamber, and an intake channel, an exhaust channel, an inlet port and an outlet port, which communicate with the chamber. The intake-exhaust assembly, rotatable within the chamber, controls the inlet port to be connected to the intake channel, and further controls the outlet port to be connected to the exhaust channel, so that the compressed gas enters the cylinder via the inlet port and the intake channel to drive the piston. After driving the piston, the compressed gas becomes an exhaust gas, which is exhausted from the cylinder via the exhaust channel and the outlet port.

Abstract: An economizer device associable with a linear pneumatic actuator includes a body having openings and a Venturi vacuum generator slidably housed in a first conduit. The device operates between a first operating configuration, where a first opening is supplied with air at an operating pressure and the vacuum generator moves in the first conduit to permit primary flow of air and to reduce outlet pressure thereof from a second opening so as to supply the chamber of the actuator with air at a reduced pressure lower than the operating pressure, and a second operating configuration, where the first opening is connected to the environment at atmospheric pressure and a third opening is supplied with pressurized air with which it supplies the vacuum generator, which creates a vacuum in the second opening in such a manner as to suck air from and create a vacuum in the chamber.

Abstract: A pressure control reservoir for a vehicle brake system is disposed in a hydraulic line extending from a master cylinder to a wheel cylinder through a pump. The pressure control reservoir includes a check valve which consists of a valve seat and a valve. The check valve is closed when an excessive pressure of brake fluid produced by the master cylinder. The valve is stationary. The valve seat is moved in response to an elevated level of the pressure of brake fluid into engagement with the valve, so that the check valve is closed. With these arrangements, the check valve is closed before a piston starts to move to change the volume of a reservoir chamber, thus permitting the volume of the brake fluid required to close the check valve to be decreased, which minimizes the uncomfortable feeling given to a driver of the vehicle when actuating the brakes.

Abstract: A hydraulic actuator assembly includes an actuator, a first sink subsystem in fluid communication with an upper working chamber of the actuator, a second sink subsystem in fluid communication with a lower working chamber of the actuator and a source subsystem in fluid communication with both the upper and lower working chambers of the actuator. A low pressure accumulator is in fluid communication with the upper and lower working chambers, the first and second sink subsystems and source subsystem. A high pressure accumulator is in fluid communication with the first and second sink subsystems and the source subsystem. The hydraulic actuator assembly can generate passive or active forces with or without energy recuperation.

Abstract: The control actuator in accordance with the invention comprises a first part with a first wall arrangement and a bottom that circumscribe an inflow volume. The first wall arrangement comprises at least one flow opening through which fluid from the inflow volume can flow. Furthermore, the control actuator comprises a second part with a second wall arrangement that is arranged so as to be adjustable along the first wall arrangement. As a result of this, the fluid flow through a flow opening can be gradually cleared or limited. Preferably, the bottom is arranged in such a manner that the bottom breaks a basic inflow direction Se into the inflow volume and shields the second part against inflow pressure surges.

Abstract: Pressure piston actuators and systems for control of wastegate in a turbocharger pressure that include the pressure piston actuators are disclosed. The pressure piston actuator includes a housing defining a chamber and a pathway leading to the chamber, a piston disposed within the chamber, a rod connected to the piston by a ball-and-socket joint, and a spring disposed in the chamber to bias the piston, and hence the rod, into a retracted position. Then, when fluid is introduced into the chamber, the fluid applies pressure to the piston. Once the pressure overcomes the bias of the spring, the piston, and hence the rod, moves into an extended position. For the system, the pressure piston actuator has the connector on the end of the rod opposite the ball-and-socket joint connected to the valve portion of a wastegate of a turbocharger.

Abstract: Disclosed herein are new types of hydraulic piston valve actuators wherein the piston is replaceable with different sized pistons. Further disclosed are parts of the piston interchange system resulting in the fewest number of parts changed between one piston diameter and another piston diameter. Methods of changing from one piston diameter to another piston diameter are also disclosed.

Abstract: A fluid-driven linear actuator comprises a piston configured for reciprocating motion in a piston chamber and a spool valve in a valve chamber. The valve chamber is fluidly connected to a fluid input and to a fluid output. The spool valve is configured to be hydraulically moved within the valve chamber between a plurality of spool valve configurations, comprising a first spool valve configuration wherein the valve chamber is fluidly connected to the piston chamber to thereby create a first fluid pressure differential which tends to force the piston in a first axial direction and a second spool valve configuration wherein the valve chamber is fluidly connected to the piston chamber to thereby create a second fluid pressure differential which tends to force the piston in a second axial direction.

Abstract: A stroke transmitter is presented. The stroke transmitter includes a conduit for providing a passage to a fluid, an actuating unit for increasing pressure in an hydraulic fluid, a valve unit configured to operate depending on the pressure of the hydraulic fluid, the valve unit arranged inside the conduit to regulate a flow of the fluid, and a pipe connecting the actuating unit and the valve unit for communicating the pressure of the hydraulic fluid between the actuating unit and the valve unit. The actuating unit is arranged outside the conduit.

Abstract: An object of the present invention is to facilitate discharge of foreign matter present around a valve member, while inhibiting degradation of seal performance of the valve member. A shock absorber includes a cylinder portion containing a liquid, a piston valve partitioning a space in the cylinder portion into a first oil chamber and a second oil chamber which contain oil, a piston rod connected to the piston valve and moving in an axial direction of the cylinder portion, a piston nut 43 (cylinder portion 433) forming a channel for the liquid between the first oil chamber and the second oil chamber, and a float valve 52 deformed or displaced depending on the pressure of oil in the channel in the piston nut 43 to open and close the channel. The float valve 52 for the channel member includes a projecting portion 52P and a recessed portion 52M so that, with the position of the float valve 52 adjusted, a gap is formed between the float valve 52 and the piston nut 43 (cylinder portion 433).

Abstract: A pressurized fluid subassembly comprising: (a) a fluid driven actuator configured to utilize fluid at a high pressure to change an overall length of the fluid driven actuator; and, (b) a sequence valve interposing a low pressure line and a supply line conveying the fluid to the fluid driven actuator, the sequence valve including a first sequence configured to inhibit fluid communication between the supply line and the low pressure line when the fluid at the high pressure is actively supplied to the fluid driven actuator, the sequence valve including a second sequence configured to establish fluid communication between the supply line and the low pressure line when the fluid at the high pressure is not actively supplied to the fluid driven actuator, wherein the sequence valve includes a variable bias that changes depending upon whether the fluid at the high pressure is actively supplied to the fluid driven actuator.

Abstract: A reciprocating compressor is provided. Bearing holes of a fluid bearing of the compressor may be positioned correspond to a full reciprocating region of a piston, to reduce/eliminate frictional loss and/or abrasion between a cylinder and the piston. The bearing holes may be concentrated at certain regions of the cylinder to stably support the piston through a full reciprocating range. Compression coil springs may maintain concentric alignment of the cylinder and the piston. Gas through holes may be radially formed at the piston to lower a pressure of a bearing space and allow refrigerant to be smoothly introduced into the bearing space through a gas pocket. A casing of the compressor may include an outer shell and an inner shell to attenuate vibration generated due to friction generated by operation of the reciprocating compressor.

Abstract: A slewing-type working machine capable of reducing back pressure generated during slewing. The slewing-type working machine includes: a base carrier; an upper slewing body; a hydraulic motor including first and second ports and slewing the upper slewing body; a hydraulic pump, a slewing operation device including an operating member; a control valve controlling the hydraulic motor based on the operation signal of the slewing operation device; first and second pipe-lines connecting the first and second ports of the hydraulic motor to the control valve; a communication switching device capable of switching communication and cutting of between both pipe-lines and the tank; and a switching command section operating the communication switching devices, when the upper slewing body is slewed, to bring only a pipe-line, which corresponds to a discharge-side pipe-line of the hydraulic motor, of the pipe-lines into communication with the tank, while bypassing the control valve.

Abstract: An end cap assembly for a reciprocating air motor comprises a pilot valve and an end cap body. The pilot has a valve stem. The end cap body comprises a central bore for receiving an air motor rod, a valve bore in which the pilot valve is disposed such that the valve stem extends through the end cap body, and an air port extending through the end cap body. The air port has a contour to direct air toward the valve stem.

Abstract: A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber.

Abstract: A pneumatic shifting force supporting device for a gearbox comprises a housing structure having a compressed air inlet and an air vent, and a control rod and an output unit comprising a working piston defining two pneumatic working chambers. A valve arrangement is functionally provided between control rod and output unit. By acting on the two pneumatic working chambers, the valve arrangement causes a pneumatic follow-up control from the output unit to the control rod comprising two valve pistons, annular sealing edges, valve spools and valve seats. A throttle slide is associated with at least one of the valve pistons and is slidable relative thereto. The throttle slide has a closing edge co-operating with the respective associated valve seat and delimiting at least one throttle passage, the cross-sectional area of which depends on the relative position of the throttle slide with respect to the associated valve piston.

Abstract: A reciprocating servo control device for a mainshaft of a honing machine includes a bed body, a mainshaft mechanism, a driving system for hydraulic reversing and a control system, the driving system includes a mainshaft hydraulic cylinder and a mechanical-hydraulic servo valve, a valve body of the mechanical-hydraulic servo valve is connected to a piston rod of the mainshaft hydraulic cylinder via a connecting mechanism, a spool of the mechanical-hydraulic servo valve is connected to one end of a first connecting member, and the other end of the first connecting member is connected to a pilot displacement mechanism controlled by a servo driving and control system. The reciprocating servo control device adopts a mechanical position closed-loop and a hydraulic position closed-loop, to achieve numerical control of speed, position and reversing of the mainshaft hydraulic cylinder, thus a simple structure, reliable control, low price and easy adjustment can be realized.

Abstract: A ram air turbine actuator includes a piston rod arranged in a cylinder. The cylinder and piston rod are configured to move longitudinally relative to one another between retracted and deployed positions. An annular space provided between the cylinder and piston rod, and a fluid flow regulating feature is provided in the piston rod. The fluid flow regulating feature is progressively blocked from the retracted position to the deployed position. The RAT actuator is deployed by initiating a deploy sequence and reducing a volume of an annular space. Fluid flow is forced from the annular space through a flow regulating feature to a cavity. The size of the flow regulating feature reduces to damp the actuator during the deploy sequence.

Abstract: A hydraulic servo-control of a servo-controlled gearbox provided with a hydraulic accumulator, having an outer housing and a piston that is slidable axially inside the outer housing and adapted to define a first variable-volume chamber for a gaseous material and a second variable-volume chamber for a control fluid under pressure; and at least one limit stop arranged at an open end of the outer housing which serve as a lower limit stop element; wherein the outer housing is provided with an upper limit stop element, which acts to limit the pressure value inside the first variable-volume chamber within a predetermined safety range.

Abstract: A vacuum lock having a main body portion, a cylinder and a piston is described. The cylinder is disposed within the main body portion and has an opening. The cylinder has one or more sealing rings disposed on an inside surface and an air vent opposite the opening. The vacuum lock can further include a piston adapted to fit in the cylinder and guides. The vacuum lock can also include a valve coupled to the air vent.

Abstract: An axial piston machine includes a housing part, a drive shaft, which is mounted in the housing part, and a cylinder drum, which is connected to the drive shaft in a rotationally fixed manner and which accommodates a plurality of pistons. Each of the pistons bound a working chamber and are supported on a swashplate. The working chambers can be connected in alternation to a high-pressure channel and to a low-pressure channel, which extend in the housing part. An insert part is rigidly inserted into the housing part. A control surface of the insert part is directly opposite the cylinder drum. The insert part has a high-pressure channel section and a low-pressure channel section, which have approximately kidney-shaped opening areas in the control surface. The other openings of the high-pressure and low-pressure channel sections opposite the opening area in the control surface are formed radially on the insert part.

Abstract: To provide an axial piston motor (1), comprising at least one main burner (2), which has at least one main combustion space (21) and at least one main nozzle space (23), and comprising at least one pre-burner (3), which has at least one pre-combustion space (31) and at least one pre-nozzle space (33), wherein the pre-combustion space (31) is connected to the main nozzle space (23) by way of at least one hot gas feed (30), that has improved operating and control characteristics even under non-steady-state operating conditions, the pre-nozzle space (33) of the pre-burner (3) has at least one auxiliary hot gas feed (40).

Abstract: The present invention discloses an actuator, which is a combination of a hydraulic control unit and a spring-mass mechanical unit, comprising: a housing, with upper and lower ports; an actuation cylinder in the housing; an actuation piston in the actuation cylinder moveable along the longitudinal axis; a first fluid space; a second fluid space; a first piston rod connected to a first surface of the actuation piston; the second piston rod connected to a second surface of the actuation piston; a fluid bypass; a first spring system connected to the first piston rod, biasing the actuation piston in the second direction; a second spring system biasing the actuation piston in the first direction; a first flow mechanism; a second flow mechanism. The present invention also discloses two other preferred embodiments. The actuator features variable valve lift, low energy consumption, fast dynamic response, soft seating and easy controllability.

Abstract: The Remotely Controlled Vehicle Pedal Actuator is a pneumatically powered tool for use in the motor vehicle repair and maintenance industry that enables a mechanic to solely, remotely, and repetitively depress and retract a vehicle accelerator, clutch or brake pedal. The device comprises a pneumatic linear actuator (commonly termed an air cylinder) that is pneumatically connected to a foot, hand or electronically activated pneumatic valve and a pneumatic power source. One end of the actuator is attached to a vehicle steering wheel with the opposite end attached to the vehicle accelerator, clutch or brake pedal. Activating the pneumatic valve pressurizes the actuator causing the actuator rod arm to extend and depress the vehicle pedal. Deactivating the pneumatic valve depressurizes the actuator causing the actuator rod arm to withdraw and retract the vehicle pedal.

Abstract: An engine with an active chamber, having at least one piston (2) mounted in a cylinder (1) in a sliding manner and driving a crankshaft (5) via a slider-crank device (3, 4) and operating according to a four-phase thermodynamic cycle includes: an isothermal expansion without work; a transfer-slight so-called quasi-isothermal expansion with work; a polytropic expansion with work; and an exhaust at ambient pressure, preferentially supplied by compressed air contained in a high-pressure storage tank (12), through a buffer capacity, called a working capacity (11), which is expanded at an average pressure, called a working pressure, in a working capacity (11), preferentially through a dynamic pressure-reducing device (13), wherein the active chamber is included in the engine cylinder, the cylinder volume being swept by the piston and divided into two separate parts, a first part forming the active chamber and a second part forming the expansion chamber.

Abstract: The invention relates to a liquid piston arrangement for compressing and expanding gases. The liquid piston arrangement includes a liquid piston which is embodied by a liquid level formed by a liquid in a high-pressure space and a stack of sheets with mutually spaced apart sheet metal plates which is supported in the high-pressure space dipping in the liquid and is sequentially flowed around by the liquid.

Abstract: An annular valve (1) has an annular valve member (4) and inner and outer annular valve seats (12, 14). Inner and outer sealing ridges (8, 10) are formed either on the annular valve member or on the valve seats. The inner sealing ridges are more resistant to plastic deformation than the outer sealing ridges. They may be thicker, or made from a harder material. Thus, the annular valve better resists damage arising from greater plastic deformation of the inner sealing ridge than the outer sealing ridge due to greater forces (Fi, Fo) acting on the inner sealing ridge than the outer sealing ridge in use.

Abstract: A reciprocating refrigerant compressor system is disclosed. The compressor system includes a cylinder, a piston disposed within the cylinder, at least one fluid passageway, and an actuator. The piston is movable between a bottom dead center (BDC) and a top dead center (TDC) position. The fluid passageway is disposed within the cylinder between the BDC and TDC position and defined by one or more apertures. The actuator is in operative communication with the aperture and is responsive to an environmental condition external to the compressor system to at least partially close the aperture.

Abstract: A positioning apparatus for moving connection equipment on a drilling rig, the positioning apparatus comprising a piston and cylinder (151,152) having a cylinder (601), a piston (607) and a piston rod (604), the piston (607) and piston rod (604) moveable relative to the cylinder (601) from a retracted position to an extended position, the positioning apparatus further comprising a transfer barrier (620) linked to the piston and cylinder (151,152) for setting a maximum extension of said piston rod (607).

Abstract: A valve assembly in a reciprocating compressor used in oil and gas industry is provided. The valve assembly comprises an actuator configured to a valve actuating motion and a valve. The valve has a valve seat comprises an inlet port configured to allow a fluid to flow through the valve seat, a counter-seat comprising an outlet port configured to allow the fluid to flow through the counter-seat, and a valve closing member attached to the counter-seat and configured to cover the inlet port when the counter-seat is in a closed position. The counter-seat is configured to receive the valve actuating motion and to move between the closed position and an open position in which the valve closing member does not cover the inlet port thereby selectively allowing the fluid to flow on a flow path which comprises the inlet port and the outlet port.

Abstract: A piston-chamber hydro-gravity engine capable of converting the stagnant volume of the liquid matter of sea, lake, pond or artificially made hydro container, to a moving volume of liquid matter that flows back upon itself and in meanwhile exploits this motion as a working agent to produce mechanical kinetic power, capable of being used for mechanical production of kinetic work for hydro-electricity generation, or to be used multi-purposely for other energy needs that demand mechanical kinetic force sufficient to solve energy production problems worldwide forever beneficial to the economy and, friendly to the environment, consisting of particular accessories of mechanisms embodied in a single system of mutual successive co-operation by exploiting gravity, that is the hydro-container (7), capable of creating the means of exploiting the gravity-hydro-static tension of squashing compression exist within the volume of liquid matter of the sea, lake, pond or artificially made containers, the cylinder-chamber (15) a