Abstract: A modular digital actuator is formed by interconnecting a plurality of modules. Each of the modules includes a housing having a pair of different sized axially extending cylinder sections in which is received a T-shaped piston with the top of the T mating with the larger cylinder and the leg of the T forming a piston in the smaller cylinder. The leg of the T is hollow and forms a cylinder to receive an axially extending piston forming shaft to thereby provide three preferably different sized cooperating piston and cylinder areas, one formed in the cavity or hollows of the leg of the T, a second formed between the top of the T surrounding the leg of the T and the junction between the larger cylinder section and smaller cylinder section and the third formed in the smaller cylinder section between a closed free end of the smaller cylinder section and the leg of the T surrounding the piston forming shaft. The top of the T forms a piston wall in a fourth hydraulic cavity.

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

Abstract: A hydraulic piston and cylinder assembly is provided with an outer sleeve attached to the piston rod. The outer wall of the cylinder has a smooth wall with a circular cross section concentric with the inner bore of the cylinder. The outer sleeve has a smooth inner bore with a circular cross section concentric with the cylinder. The outer sleeve is arranged to slide along the outer wall of the cylinder to provide a sliding linear bearing that resists lateral loads that would otherwise be taken up by the piston and piston rod at their contacts with the cylinder. The sleeve distributes the lateral load over a greater surface area and supports the forces with a stronger structure than conventional assemblies. The sleeve, cylinder and piston have concentric circular cross sections to permit rotation about the central axis without binding. The sleeve has a lubricous plastic lining to enhance sliding contact with the outer wall of the cylinder.

Abstract: A work cylinder in which the position of a work piston, its distance traveled at a given time and the speed at which it covers this distance are measured by a hollow-cylindrical sensor, and the results are delivered to an electronic switch device. The sensor serves as a passage for the breathing air of a breathing chamber of the work cylinder, as a result of which the sensor can be cooled. The work cylinder is intended for use to control vehicle engine clutches.

Abstract: A rotary/linear fluid actuator includes a cylinder closed at one end by a rotary actuator and at its other end by a forward housing. A piston is disposed in the cylinder. A hollow piston rod, the forward end of which is closed, extends out of the cylinder through the forward housing. A splined shaft extends into the open end of the piston rod and is coupled to the rotary actuator. The splined shaft includes an axial bore therethrough for delivering pressurized fluid to the piston rod cavity to cause extension of the piston. The piston, cylinder and forward housing define a cavity which is pressurized to cause retraction of the piston. According to the invention, the size of the piston surface can be selected independent of the size of the piston rod cavity actuation surface so that extension and retraction forces, and thereby fluid requirements are independent of one another.

Abstract: A prosthetic leg has a pivotal knee joint and a hydraulic fluid control unit connected to provide variable forces which dampen flexion and extension of the knee and also bias the leg to its extended position. The unit includes an aluminum housing lined with an axially adjustable sleeve and control bushing defining a cylindrical chamber which receives a piston mounted on a tubular piston rod. The housing and chamber receive hydraulic fluid or oil which flows during movement of the piston through fluid control ports, channel and adjustable gaps defined by the sleeve and bushing for damping the movement of the rod. The piston rod encloses a gas filled flexible bladder which forms an oil accumulator during inward movement of the piston rod and also produces variable forces for moving the piston rod outwardly to its extended position. The housing confines a gap defining ring which compensates for changes in oil viscosity with heat.

Abstract: An actuator including a cylinder having a longitudinal bore, a piston slidably and sealingly inserted into the cylinder, and a lock mechanism for temporarily locking the piston, the cylinder including a cylinder body having the longitudinal bore, a cylinder formed at a front end of the cylinder body and accommodating the lock mechanism, and a front wall connected to the cylinder head at a position opposite to the front end of the cylinder body and having a hole formed therein, the piston including a piston head slidably and sealingly inserted into the cylinder bore, the piston rod projecting from the piston head and slidably insertable into the hole of the front wall, a key groove formed on the piston rod at a position near the piston head, and a longitudinal hole formed within the piston head and the piston rod, wherein the diameter of the piston rod decreases from a backward position adjacent to the key groove to a forward position spaced from the piston head.

Abstract: In a hydraulic servo unit comprising a cylinder and a piston slidably inserted therein, the cylinder chamber being divided by a piston portion into a rod-side cylinder chamber and a head-side cylinder chamber, a control apparatus for the hydraulic servo unit includes but is not limited to a first hydraulic line connecting the rod-side cylinder chamber with the hydraulic pressure source which supplies working fluid of a predetermined pressure, a second hydraulic line connecting the head-side cylinder chamber with the first hydraulic line through a first solenoid valve of duty-ratio-control, and a drain hydraulic line connecting the head-side cylinder chamber with drain through a second solenoid valve of duty-ratio-control.

Abstract: In an hydraulic cylinder for vehicle braking elements, a clamping piston (1) moved in a housing (3) by hydraulic pressure acts relative to a brake lining carrier bearing a brake lining, e.g., in the form of a brake shoe which, during braking, is forced against the brake disk. To prevent the clamping piston (1) in rest position from being pushed back into its housing (3) by axial impact forces, the clamping piston (1) can be coupled at its interior to an hydraulic volume, which, in the neutral position of the clamping piston (1), acts as an hydraulic cushion and counteracts the impact forces.

Abstract: The vacuum servomotor comprises a main casing (12) divided sealingly on the inside into first and second chambers (10, 20) by a flexible membrane (9) bearing on a rigid disk (7) integral with an activating piston (3). The first chamber (10) is subjected to a low pressure, while the second chamber (20) is subjected either to this low pressure or to a higher pressure. An auxiliary casing (25) is integral with the rigid disk (7) and projects into the first chamber (10), an auxiliary piston (27) sealingly dividing the auxiliarly casing (25) on the inside into third and fourth chambers (30, 40), the third chamber (30) being closed by the rigid disk (7), the auxiliary piston (27) being mounted stationary relative to the main casing (12).

Abstract: A wellhead mounted pneumatic actuator for bottom hole oil pumps designed for operation by compressed air or gas. The preferred embodiment utilizes a single action cylinder with the downstroke actuated by the weight of the sucker rods and the fluid contained therein. Sufficient relatively high pressure air or gas from an external source is supplied under the piston of the cylinder to lift the piston at all times. A pressure or solenoid control floating piston bleeder valve selectively routes air or gas into the power cylinder on both sides of the piston to accomplish the downstroke. First and second contactors are mounted to cables suspended from a spreader reciprocating with the piston to contact respective first and second pivot arms to pivot the pivot arms into engagement with the respective first and second activator buttons of the bleeder valve to shift the bleeder valve from one position to the other to effectuate the selective routing of air or gas to the top of the piston as well as under the piston.

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

Abstract: The invention relates to a piston having a variable compression height and two control chambers connected to each other through a hydraulic system. In order to achieve better cold-start and warm-up behavior, an oil discharge bore from the upper control chamber into the crankcase is closed by a control slide valve in the cold operating state of the engine. The blockage of the oil discharge produces a great compression height and therefore high compression. The control slide valve is connected to an expansible element which maintains it in this closed position when the engine is cold. As the engine warms up, the expansible element, due to its thermal expansion, pushes the control slide valve out of its closed position, so that the discharge of oil can occur progressively more unthrottled with rising temperature. In the warm operating state of the engine the control slide valve clears the oil discharge duct completely, and an unobstructed discharge of oil is ensured.

Abstract: A lifting apparatus has two posts on either side. A lifting or cross member extends between them and is supported on carriages slidably mounted on the posts. Support arms or the like extend out from the support carriages for supporting a vehicle or other load. Actuators are provided for driving the carriages up and down. The actuators can be hydraulic cylinders connected in a master and slave relationship with a hydraulic connection between them through the cross member. Additionally, mechanical safety catches can be provided which are connected by a cable or the like through the cross member, to permit a single handed operation of them. In the further aspect of the invention, a mechanism is provided for locking the support arms angularly, which mechanism includes plungers that contact the ground and automatically free the support arms when the apparatus is lowered.

Abstract: An improved fluid supplying and exhausting arrangement for fluid-powered rotary motion actuating devices of the dual piston rack-and-pinion type. A first conduit arrangement includes a central opening through an axial end wall of the actuator housing and a fluid transfer tube fitted in such opening and extending axially through the adjacent piston into the intermediate fluid chamber between the two pistons for delivering fluid and exhausting fluid from the intermediate chamber, with the adjacent piston being slidable on the transfer tube in sealing contact therewith. A second conduit arrangement includes another axial opening in the end wall into the adjacent outward chamber of the housing and another transfer tube fixed to and extending axially through one piston and extending axially through the other piston to open at the opposite ends of the tube into the two outward fluid chambers of the device, with the other piston being in axially slidably sealing contact with the second tube.

Abstract: A closing mechanism of an injection molding machine has a piston-cylinder unit to be pressurized hydraulically. Two partial strokes can be carried out in the unit, of which the first can be run through faster than the second. A displacement tube (7) extends into a main cylinder chamber (6) and into an inner cylinder chamber (4) of a piston (2) of the piston-cylinder unit. The displacement tube (7) is fastened to an end wall of the main cylinder (1) and is open at its free end. The piston (2) is designed as a plunger and is spaces on all sides from the cylinder wall (5) of the cylinder (1) of the piston-cylinder unit. The piston (2) is guided in a flanged gland (15) which is screwed to the cylinder (1).

Abstract: A multi-chamberal hydraulic cylinder and valve system utilizes a single relatively low flow rate pump to provide pressurized fluid during travel, compression and retraction of the piston rod. The piston rod has an effective diameter greater than its physical diameter due to the additional forces applied on an annular piston which is also used to extend and retract the piston rod without supplying pressurized fluid to the interior of the hollow piston rod except during the compression portion of the stroke.

Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylindrical wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.

Abstract: The chuck or collet actuating apparatus for a machine tool comprises a rotating clamping cylinder, an axially slidable clamping piston rotating with the clamping cylinder and a coaxial cylindrical projecting portion in the clamping cylinder. The projecting portion carries a thread, on which a threaded ring is guided and engaged. This threaded ring is provided with a coaxial undercut annular groove in an opposing surface facing the clamping cylinder and is securable against rotation on the projecting portion. A plurality of stop pins are provided which are axially unshiftable relative to the threaded ring and which engage and slide in the annular groove. The stop pins project through an opposing wall of the clamping cylinder into an interior space of the cylinder axially slidable and sealing axially. These stop pins form a stop for the clamping piston limiting its displacement.

Abstract: The space within the interior cavity (7) of the piston (1) limited by the partially spherical head (5) of the connecting rod (6) is filled with a viscous, pasty or plastically ductile fluid (13), practically incompressible at the operating temperatures and pressures of the piston (1), the diameter (D) of the cylindrical support (8) which limits laterally the cavity (7) being very slightly greater than the diameter (d) of the partially spherical head (5) of the connecting rod (6) so that the clearance during operation between said support (8) and said head (5) is sufficiently minor to prevent any leakage of said fluid (13) from said space at the operating temperatures and pressures of the piston.

Abstract: A compact master cylinder suitable, for example, for vehicle clutch or brake systems. An integral fluid reservoir body is connected to a piston stem extending to a piston head in the cylinder. The stem has a longitudinal passage connected to an orifice at the reservoir inlet. This orifice is valved by a valve closure member having a spherical head and an elastomeric cap. In the retracted state a stop secured to the cylinder limits movement of the piston out of the bore and the valve closure member opens to allow entry of make-up fluid from the reservoir.

Abstract: A mixing device for liquids is described, wherein improved control of the mix is achieved by restructuring the components so that the character of the mix can be observed easily and corrections effected simultaneously. The disperser/mixer incorporates a moveable and rotatable support structure attached to a piston-in-cylinder arrangement. Hydraulic pressure, pneumatic pressure, or a combination thereof in the cylinder is controlled from a unit on the support structure, rather than the base, through a modified piston fixed to the support structure and containing a passageway for hydraulic fluid, rather than through the cylinder.

Abstract: Disclosed is a fluid powered linear slide employing either a rodless or rod-type cylinder. The slide includes a base which has a movable carriage mounted thereon which moves reciprocably in response to pressurized fluid being fed to the cylinder. In the embodiment employing a rod-type cylinder, a pair of tubular rods are mounted on the base in a fixed position and attached to a piston stationarily mounted inside the cylinder which is movably mounted and attached to the carriage. In the other embodiment, the carriage is mounted on a bracket which is attached to the rodless cylinder carried in the housing for the cylinder. The base has linear guideways therein, each guideway carrying one or more stop members which are manually adjustable and electrically or fluidly actuated.

Abstract: A hydraulic cylinder comprising a hollow sleeve, having inserted in it, a hollow piston rod. The hollow sleeve further contains an opening allowing hydraulic fluid to pass therethrough and into the hollow piston rod. At the end remote to the opening, a mounting mechanism is contained. On the end proximate the mounting mechanism, a fluid outlet is contained. In use, hydraulic fluid passes through the opening of the hollow sleeve, into the piston rod, and out of the piston rod proximate the mounting mechanism.

Abstract: A combined pneumatic and hydraulic pressure transducer is comprised of a pressure capsule with an open interior divided into first and second sections by a partition wall, and a respective axially displaceable diaphragm extends across each of the sections defining third and fourth pressure chambers which change in volume due to axial displacement of the respective diaphragms. A rigid piston intermediate member extends through the partition wall and joins the diaphragms to move together. Connections communicating between the third pressure chambers and between the fourth pressure chambers pass through the intermediate member. A respective hydraulic cylinder at each end of the pressure capsule receives and operates upon a respective end of the intermediate member.

Abstract: The debarking machine of the instant invention includes a frame having a stationary central hub, a ring rotatably mounted on the frame for rotation about the hub having air-pressure-actuated tools carried on the ring. Power means are provided for rotating the ring. Air passage means extend from the central hub to the ring for supply actuating air to the tools. Air passage means includes a rotary-air-seal coupling, which comprises a substantially U-shaped channel formed of a pair of opposed L-shaped annular structures which extend about the hub and have a first air plenum carried therein. A pair of annular, floating seals are disposed on the interior side walls of the U-shaped channel and a rotary disc, having a second air plenum therein, is mounted on the ring and received in the U-shaped channel, in rotatable contact with the air seals.

Abstract: Disclosed is a fluid powered linear slide employing either a rodless or rod-type cylinder. The slide includes a base which has a movable carriage mounted thereon which moves reciprocably in response to pressurized fluid being fed to the cylinder. In the embodiment employing a rod-type cylinder, a pair of tubular rods are mounted on the base in a fixed position and attached to a piston stationarily mounted inside the cylinder which is movably mounted and attached to the carriage. In the other embodiment, the carriage is mounted on a bracket which is attached to the rodless cylinder carried in the housing for the cylinder. The base has linear guideways therein, each guideway carrying one or more stop membes which are manually adjustable and electrically actuated.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of rotating circular discs having cooperating friction surfaces for engaging a running yarn at a twisting zone. A pressure applying member is positioned to apply a biasing force to the rear surface of one of the discs locally at the twisting zone, and the pressure applying member comprises a receptacle slideably mounting a piston which extends from the end of the receptacle to engage the disc. The receptacle is eccentrically mounted to permit selective positioning of the biasing force with respect to the yarn path of travel. The discs are mounted on pivotal rocking arms whereby the ratio of yarn twist to yarn speed may be adjusted, and an eccentrically mounted pin provides closely controlled adjustability for the arms and thus the twist ratio.

Abstract: A well casing penetrator includes an elongated housing enclosing an outwardly movable hydraulic cylinder driven punch for cutting an opening in a casing. A high pressure liquid jet nozzle is mounted on the end of a hose which moves outwardly through an axial bore in the punch when extended through the casing to cut a radially extending opening in the surrounding earth. The punch includes arcuately curved longitudinal slots along opposite sides which cause tabs to be bent back along opposite sides of the opening cut in the casing to prevent dislodging of any portion of the casing from the casing as a consequence of the operation of the punch. A spool piston is connected to a single accumulator that is pressurized to urge the spool piston toward a first position in which work fluid controlled by the spool piston retracts the hydraulic punch cylinder and a hose drive cylinder for moving the hose in the punch.

Abstract: A slurry pump has slurry hopper and dual pumping cylinders. The slurry pumping members are driven by opposite-phase actuators. Each actuator has a rigid-hollow-stem partition dividing the space between the actuator plunger and the cylinder into two drive chambers of different areas selectively supplied with pressurized fluid to drive the plunger with a selected force and speed. An associated valve shuts off flow to one of the drive chambers and is controlled at any given time to occupy the same position as a corresponding valve of the other actuator. The valves coordinate supply of fluid to corresponding drive chambers on alternate strokes of two actuators.

Abstract: Conventional piston-cylinder hydraulic actuators require external pressure sources. The hydraulic actuator disclosed utilizes the centrifugal head developed in its chambers. The piston (36) is attached to shaft extension (24) which is splined to the actuator cylinder (20). The cylinder (20) rotates with the shaft (16) to develop a centrifugal fluid head which is selectively directed from the outlet port (40a, 40b) of a contracting chamber through a servo valve (46) to the return passageway (46b, 46a) of an expanding chamber to axially displace piston (36) and shaft (16). An accumulator in the fluid circuit retains fluid displaced from the cylinder (20).

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

Abstract: Piston rods (60, 62) of three linear hydraulic motors (36, 38, 40) are connected at their outer ends (64, 68) to two spaced apart transverse frame members (10, 12). A cylinder housing (72) is driven back and forth along each pair of piston rods (60, 62). Three transverse drive beams (48, 50, 52) are provided. Each drive beam (48, 50, 52) is directly connected to an associated one of the cylinder housings (72). Three sets of floor slat members (1, 2, 3) are provided. Each set (1, 2, 3) is connected to an associated one of the transverse drive beams (48, 50, 52). The linear hydraulic motors (36, 38, 40) are operated for moving the floor slat members (1, 2, 3) in one direction, for advancing a load, and for retracting them in the opposite direction. Each cylinder housing (72) has four fluid chambers (82, 84, 86, 88). The first and third chambers (82, 86) are interconnected and the second and fourth chambers (84, 88) are interconnected.

Abstract: The casing of the jack is divided into two cylinders by a cross partition, with a first piston which moves in one of the cylinders and a second piston, forming two parts, linked by a rod which crosses the partition to its first part which moves in the first cylinder-shaped piston and its second part which moves in the second cylinder of the jack. The fluid is conveyed selectively either to the cylinder formed by the first piston or to the second cylinder which communicates with the first cylinder through holes drilled in the partition.

Abstract: Piston rods (60, 62) of three linear hydraulic motors (36, 38, 40) are connected at their outer ends (64, 68) to two spaced apart transverse frame members (10, 12). A cylinder housing (72) is driven back and forth along each pair of piston rods (60, 62). Three transverse drive beams (48, 50, 52) are provided. Each drive beam (48, 50, 52) is directly connected to an associated one of the cylinder housings (72). Three sets of floor slat members (1, 2, 3) are provided. Each set (1, 2, 3) is connected to an associated one of the transverse drive beams (48, 50, 52). The linear hydraulic motors (36, 38, 40) are operated for moving the floor slat members (1, 2, 3) in one direction, for advancing a load, and for retracting them in the opposite direction. Each cylinder housing (72) has four fluid chambers (82, 84, 86, 88). The first and third chambers (82, 86) are interconnected and the second and fourth chambers (84, 88) are interconnected.

Abstract: In a fluid pump or motor improvements are provided to the piston shoes therein to permit a higher pressure in the respective device. Other improvements are done to the hydrostatic bearings in radial piston or radial chamber type fluid motors and pumps. A further arrangement is, that plural pistons are applied to permit the use of two different fluids in the respective device. This leads also to the application of disc springs and their modification in a pump or motor to make the pumping of non-viscous fluids like water possible at very high pressure. Motors are provided with arrangements to permit them to drive and to carry simultaneously or to have hollow shafts, whereby improved and novel machines and vehicles are obtained.

Abstract: Disclosed herein is a slide cylinder basically consisting of a cylinder block internally defining a plural number of intercommunicating cylinder bores in parallel relation with each other, a piston and a piston rod fitted in each cylinder bore, and plate-like cross members integrally connecting the respective piston rods at the opposite ends thereof. The drive chambers defined by the pistons are communicated with fluid supply/discharge ports at the opposite ends of one of the piston rods and one of fluid supply/discharge ports provided in the cylinder block, permitting a diversity of piping modes by selective use of these ports. When installed upside down, it is possible to move either the cylinder block or cross plates whichever is desired. The slide cylinder can transfer loads accurately without involving rotational motion. Fixing of a piston against a piston rod is by means of caulking the ends of cylindrical portion of a piston at fixing grooves of a piston rod.

Abstract: Piston rods of three linear hydraulic motors are connected at their outer ends to two spaced apart transverse frame members. A cylinder housing is driven back and forth along each pair of piston rods. Three transverse drive beams are provided. Each drive beam is directly connected to an associated one of the cylinder housings. Three sets of floor slat members are provided. Each set is connected to an associated one of the transverse drive beams. The linear hydraulic motors are operated for moving the floor slat members in one direction, for advancing a load, and for retracting them in an opposite direction. Each cylinder housing has four fluid chambers. First and third chambers are interconnected and the second and fourth chambers are interconnected. This arrangement provides adequate force producing area with a relatively small diameter cylinder housing. Fluid passageways are formed in the piston rods. Transfer valves are incorporated in end portions of some of the linear hydraulic motors.

Abstract: In a booster type high-pressure container including an outer cylinder associated with upper and lower lids and an inner cylinder fitted in the outer cylinder with a gap clearance retained therebetween, a booster chamber is provided between a piston disposed within the inner cylinder at its bottom portion and the lower lid of the outer cylinder, a boosting liquid medium is injected into the booster chamber for pushing up the inner cylinder jointly with the piston to boost the pressure within the inner cylinder, and the gap clearance communicates with the booster chamber.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of rotating circular discs having cooperating friction surfaces for engaging a running yarn at a twisting zone. A pressure applying member is positioned to apply a biasing force to the rear surface of one of the discs locally at the twisting zone, and the pressure applying member comprises a receptacle slideably mounting a piston which extends from the end of the receptacle to engage the disc. The receptacle is eccentrically mounted to permit selective positioning of the biasing force with respect to the yarn path of travel. The discs are mounted on pivotal rocking arms whereby the ratio of yarn twist to yarn speed may be adjusted, and an eccentrically mounted pin provides closely controlled adjustability for the arms and thus the twist ratio.

Abstract: This is a fluid-operated linear-rotary robot-like actuator reconstructed from a standard fluid cylinder device. The solid piston of the standard cylinder device is replaced with a self-contained vane-operated piston structure formed of spaced piston parts and an interposed vane chamber and in which a vane-operated work piston is rotated. The work piston extends through the forward cylinder head. A second piston rod extends from the rear part of the piston structure through the rear cylinder head and has passages for supplying the vane chamber of the piston with fluid under pressure. Suitable push button and microprocessor control systems, either by push button or automatically, are provided for controlling the operation of the actuator to give combined linear and rotary movement to a robot hand.

Abstract: A reversing and adjustment mechanism, especially for a reversible plough adapted for hydraulically adjustable furrow width and hydraulic reversing of the plough, wherein the reversing and adjustment mechanism comprises a hydraulic cylinder (8) with a "hydraulic memory" for adjustment of the furrow width. The oil chambers on both sides of the ordinary piston (15) in the adjustment cylinder (8) communicate with a reservoir (24) via two pilot-controlled check valves (26, 25) with open passage toward the adjustment cylinder (8) and a second direction-control valve (10). The chamber (31) in the adjustment cylinder (8) between the rear head and a freely movable piston (17) communicates on the one hand with a hydraulic cylinder (7) for reversing the plough, preferably with the rod end thereof, via a first check valve (14) with open passage toward the reversing cylinder (7), and on the other hand communicates with the reservoir (24) via a flow-control valve (28) and a first direction-control valve (9).

Abstract: A pressure sensor has a housing in which at least two diaphragms are secured in such a manner that they include a volume which is filled with a hydraulic fluid. The incompressible hydraulic fluid serves to transmit pressure between the diaphragms. For introducing the hydraulic fluid one diaphragm is provided with an opening. A narrow tube is connected in fluid-tight manner to the edge of the opening. The hydraulic fluid is introduced through the initially still open end of the narrow tube. After the filling with hydraulic fluid the open end of the narrow tube is sealed in fluid-tight manner, for example by squeezing. The narrow tube can serve at the same time a force-transmitting or travel-transmitting member which connects the diaphragm to a force or travel sensor.

Abstract: A hoseless arrangement for supplying pressure and tank passages in remote hydraulic device including an extend tube, with pressure and tank passages, and an extend cylinder each reciprocably mounted on a base with a pair of concentric tubes attached to the extend cylinder and to the extend tube, the inner tube communicating with one side of the extend cylinder and the outer tube with the other side thereof. A shuttle valve on the extend tube is connected to shift so that the pressure passage is always subjected to high pressure and the tank passage is always subjected to low pressure.

Abstract: A piston and cylinder assembly, a power assisted steering gear which includes such an assembly and a method of forming a piston for such an assembly. A rack and pinion type power assisted steering gear has a rack member 2 coupled to a piston member 6 slidable within a cylinder 16 and forming therewith a double acting servo motor fluid pressure supply and exhaust from chambers 21 and 22 of which is controlled to provide power assistance to displacement of the rack member 2. The piston member 6 has a piston part 10 integrally formed with rod parts 11 and 12 which extend axially from opposite sides of the piston part.

Abstract: Disclosed herein is a power feed system for translating a rotary drill head along the length of a guide tower. The system utilizes a compound balanced area, end fed hydraulic cylinder as the actuating means. This arrangement provides a large ratio of fixed overall length to usable travel distance, balanced feed force in both directions, direct connection of the rotary head to the outer stage of the cylinder, and drift-free operation, all without the need for moving hydraulic hoses.

Abstract: An hydraulic jack having more than two chambers is disclosed and is intended for use in a system of jacks, the displacement of which is to be synchronized. Each jack has a cylindrical center cavity in which a piston with a cylindrical cross section reciprocates, an annular cavity in which a piston with an annular cross-section reciprocates, and a rod for transmitting thrust connected to both pistons. In order to provide the jack with a minimum longitudinal dimension and with maximum rigidity, the two cavities are concentric and are separated by a stationary intermediate wall. The two pistons are connected to the rod for the transmission of thrust.

Abstract: In order to enable a piston cylinder unit 1,2 with air entry through a hollow shaft 6, to be operated in either mode of operation with a single type of shaft, it is proposed in accordance with the invention to manufacture the shaft 6 in three parts, namely an upper air inlet portion 6a, an intermediate portion 6b which provides access for air to the cylinder via one or more apertures 18, and an operating end portion 6c. These three parts are threaded together and sealed by seals 21 and 24. Captive nuts 3 and 8 are provided at both ends of the cylinder so that the cylinder may be attached to a yoke 4 by either end, with the opposite end carrying a bearing 9 for the air inlet portion 6a of the shaft. If it is desired for the piston to operate in the opposite mode of operation, the portions 6a and 6c are interchanged and the cylinder is attached to the yoke using the captive nuts 8 rather than the nuts 3.

Abstract: A double acting telescopic hydraulic cylinder comprises a hollow base member arranged to be supported pivotally and including a removably end closure at its inner end. The interior surface of the base member incorporates a set of machined grooves which removably mount a set of rings that act as a stop, a fluid seal, a bearing and a wiper for the largest of a plurality of telescoping cylinder stages each incorporating a similar set of internal machined grooves and rings which cooperate with the adjacent smaller stage. The smallest telescopic cylinder stage receives a hollow telescopic piston stage closed at its inner and outer ends. An internal groove on the inner end of each telescoping cylinder stage removably mounts a lifting ring for engaging the next smaller stage. An external groove on the inner end of each stage removably mounts a guide bearing ring for cooperation at its forward end with the stop ring of the adjacent larger stage.

Abstract: There is provided a hoist as for an ocean floor dredging operation, which is capable of providing hydraulic heavy lifting capacity, for raising or lowering the dredging means between a surface ship and the ocean floor, and further can routinely provide the ship heave compensation when lifting capacity is not required, for example during dredging operation, or if the raising or lowering of pipe during pipe deployment and retrieval operations is discontinued for any other reasons, such as extremely high seas. The pneumohydraulic system comprises a piston slidably sealably movable within a cylinder and dividing the cylinder into upper and lower portions; a pneumohydraulic accumulator for providing hydraulic fluid to each of the cylinder portions and the necessary valve means to open and close the necessary connections for filling and evacuating one of the cylinder portions with hydraulic fluid without rendering hydraulically inoperative the second portion of the cylinder.