Abstract: This electrohydraulic actuator comprises a pair of hydraulic rams (12, 13) and a rocker (14) integral in terms of rotation with an input shaft (7) of the barrel, the rams are arranged parallel with one another in such a way as to be able to control the rotation of the rocker to make it adopt predetermined angular positions corresponding to the gears (R, N, 1, 2, . . . ) selected and this actuator also comprises solenoid valves for controlling the rams. The rocker (14) extends transversely to the shaft (7) and its ends are designed to be able to interact with respective pistons (17, 18) of the rams (12, 13), each ram comprises three pistons (24, 25, 17; 26, 27, 18) which are coaxial and have different cross sections, arranged in chambers (28, 29) of corresponding cross sections formed in the body (11). This electrohydraulic actuator permits extremely quick and easy control of gear selection for a structure which is relatively simple and has a modest cost of manufacture.

Abstract: A mechanism for setting the two end positions of a piston for a turning shaft of the rack and pinion type, being equally applicable to driving gears which use slotted or other guides as a system of conversion of lineal into turning movement, the mechanism consisting of a piston which moves alternatively from inside a sleeve, with one of the ends closed by a cover. The movement of the piston in either direction is effected by means of a fluid, and this movement is what starts the action over the corresponding turning shaft, whose rotary transmission can be effected by means of a rack and pinion or other type of element.

Abstract: A fluid-controlled actuator assembly for a gearbox of a vehicle. The actuator is provided with a four-position mobile element, with a first and a second chamber separated in a sealed manner from the mobile element, and with auxiliary positioning elements suitable for determining a stop position of the mobile element. Also included are first and second solenoid valves suitable for supplying pressurized fluid respectively to the first and to the second chamber and for discharging it from them, such that when the fluid is supplied into both the chambers, the mobile element is maintained by the auxiliary positioning elements in the stop position. When the fluid is supplied into one of the chambers and is discharged from the other, the mobile element adopts one of two lateral positions with respect to the stop position.

Abstract: In a linear actuator, a cylinder is separated into forward and reverse chambers by a piston. A lead screw is threadedly engaged in the piston and a piston rod connects to the load. A turbine applies torque to the screw to urge the screw toward clockwise or counterclockwise rotation depending on the direction of the piston movement. The tangent of the lead screw helix angle is so substantially equal to the coefficient of friction between the piston and the screw that the torque generated by the turbine does not significantly vary the force exerted on the load and the force on the load does not significantly vary the speed of movement of the load. Variations between the static and dynamic coefficients of friction between the lead screw and the piston can be offset by selection of an appropriate lead angle and friction coefficient in the turbine driven system.

Abstract: A pneumatic device 10 comprises a piston 12 moveable along a cylinder 10. The piston has opposite ends 18, 26 defining a space 30 therebetween. The space is divided into two chambers 30a, 30b by a housing 40 fixed relative to the cylinder and having a fluid flow control passageway 42 therethrough. The space 30 is filled with fluid, such as oil. The piston 12 is arranged such that movement thereof against a spring 16 causes the fluid to be displaced from one chamber 30a of the space 30 to the other chamber 30b through the passageway 42. The spring 16 is arranged to apply a return force to the piston 12 and the rate of return of the piston 12 is controlled by the return flow of fluid through the passageway 42. A pneumatic system 100 includes a device 10 connected between first and second members 58, 58a of a building, such as a door and door frame.

Abstract: A compact drive cylinder with a cylinder barrel, an end cap and a guide cap is provided. In the cylinder barrel an axially sliding piston is arranged, on which a piston rod is mounted which extends through the guide cap. The piston divides a thrust chamber off in a fluid-tight manner chamber from a return chamber, the thrust chamber being connected with a thrust chamber port and the return chamber being connected with a return chamber port respectively in a fluid-tight fashion. Both the thrust chamber port and also the return chamber port are arranged in the end cap. An axially extending abutment rod having an abutment extends through the end cap and has its internal end extending through the piston into the return chamber so that an abutment for the piston is located in the return chamber.

Abstract: The invention has its object to provide a diaphragm type high pressure shut-off valve which is simple in external shape, can realize miniaturization and is convenient in handling.The shut-off valve comprises a cylindrical housing (10) having a supply unit for compressed air at its end in an axial direction (Q), a piston (19) provided in the housing (10) and adapted to reciprocate in response to the compressed air, a return spring (20) provided in the housing (10) so as to permit the piston (19) to return, a rack portion (19A) provided to extend from the piston (19), a cam pinion (17) having a pinion portion (17B) provided integrally with the pinion portion (17B) and a rotating shaft (18) supported by the housing (10), and a diaphragm (7) adapted for movement in response to displacements of stems (9,13) and abutting against the cam face portion (17A) of the cam pinion (17).

Abstract: An actuator for a ram-type blowout preventer used either with a shear ram blowout preventer or a pipe ram blowout preventer. The actuator includes a pressure-responsive cylinder having an operating piston disposed therewithin. The piston includes a shaft for transmitting relative motion to the ram in the blowout preventer. A reversible annular member is disposed around the periphery of the piston to provide a variable pressure force in a shear ram blowout preventer and to limit the stroke of the piston in a pipe ram blowout preventer. The annular member includes a pair of annular flanges extending radially inward to form a channel therebetween. The channel receives the periphery of the piston which is moveable within the channel between the flanges. In a shear ram blowout preventer, the annular member increases the annular pressure area of the piston during the shearing stroke to increase the pressure force on the rams and their seals during the shearing of the pipe.

Abstract: A fluid-powered rotary actuator for providing rotary movement between first and second external members. The actuator includes a cylindrical body with first and second ends. The body is adapted for coupling to the first external member, and a shaft extending generally coaxially within the body and supported for rotation relative thereto. The shaft having an adjustable end limit of rotation relative to the body. The shaft has an end portion adapted for coupling to the second external member to provide rotational movement between the first and second external members. An annular body insert is positioned coaxial with the body and at least partially within the body at the body first end. The body insert is formed as a separate part from the body and is adjustably rotatable relative to the body to permit adjustment of the end limit of rotation of the shaft relative to the body. The body insert is restrained by the body against axial movement relative to the body during powered operation of the actuator.

Abstract: A load positioning apparatus comprises a rodless cylinder which comprises a piston and a load-mounting table connected together by a coupling device, a feed screw turned and driven by an electric motor, and a pressurized fluid control and supply device. The coupling device mechanically and directly connects the piston and table. The feed screw disposed to pass through the piston in the rodless cylinder is connected to the piston with a screw coupling mechanism.

Abstract: In a linear actuator, a cylinder is separated into forward and reverse chambers by a piston. A lead screw is threadedly engaged in the piston and a piston rod connects to the load. A turbine applies torque to the screw to urge the screw toward clockwise or counterclockwise rotation depending on the direction of the piston movement. The tangent of the lead screw helix angle is so substantially equal to the coefficient of friction between the piston and the screw that the torque generated by the turbine does not significantly vary the force exerted on the load and the force on the load does not significantly vary the speed of movement of the load. Variations between the static and dynamic coefficients of friction between the lead screw and the piston can be offset by selection of an appropriate lead angle and friction coefficient in the turbine driven system.

Abstract: A stepping actuator having a housing containing two linearly reciprocating members independently and axially slidable, and a common rotating member passed through them. One of the housing and linearly reciprocating members has endless circulating grooves formed by tilted grooves interconnected by circumferentially extending grooves while another one of them holds projections adapted to fit in the circulating grooves. The circumferentially extending grooves have a circumferential length equal to a circumferential length of an opposite tilted groove corresponding to another of said slidable reciprocating members. The linearly reciprocating members and rotating member are linked together by a coupling that transmits the rotary motion while allowing free axial motion.

Abstract: An elongated sleeve, externally threaded, is threadedly engaged with threaded bores in transverse walls formed in a straight cylinder of a gas compressor. A nut is secured to an intermediate portion of the sleeve, by means of a setscrew, and an end of the sleeve threadedly mounts a valve. The cylinder wall has an aperture formed therein to provide access for an open-end wrench, so that the wrench can work the nut to cause rotation of the nut and the sleeve, and move the valve outwardly or inwardly of the cylinder, as the valve is wholly confined within the cylinder at the frame-end thereof, and is otherwise inaccessible for movement.

Abstract: A drive for turning a pinion shaft provided with toothed ridges by means of a rack the latter is connected on both sides with pistons, which in each case are held by a cylinder with the formation of a working space which may be acted upon by a pressure medium and closed by a cover or piston. In this case, the rack may be mounted for relative movement with respect to a toothed piston. The rack as well as the toothed piston engage with their teeth the toothed ridges of the pinion shaft.

Abstract: A hydraulic operating device for gate movement comprises a gate pintleing unit (10) comprising a box (11) with rotating support body (37) for a shaft (12) having a first gear (20) integral therewith projecting into the box. The shaft (12) faces at the top a box (11) with one of its axial fixing ends (15) integral with the gate rotation axis. The device also comprises a hydraulic operating unit made up of a drive element (25) consisting of a central body (32) from which project opposed hydraulic cylinders (26,27) in which run respective pistons (28,29). Between the pistons is connected a rack (30) traversing the central body (32) to project laterally therefrom with its teeth. It is thus possible to prepare a gate for future automation by mounting only the box and subsequently inserting therein the operating unit.

Abstract: The field of the invention is one in which an electric motor drives a helically grooved shaft to displace a hydraulic fluid pumping piston to feed the hydraulic fluid under pressure through a flow directing and control system to energize the motion of a piston on a helically grooved second shaft to drive the second shaft which is able to supply the motion power to drive a vehicle, or to provide power to drive a shaft for other useful purposes, and to apply the mechanical advantage to be developed between pistons having a small and a large area relationship in a closed hydraulic fluid circulating loop where electric drive for one piston results in power output from the other piston.

Abstract: A motion conversion system by which near 100% of a reciprocating motion, and a rotary motion, fluently converted from one to the other includes, a drive shaft (20), an intermediate circular element (22), externally teethed to near one-half of its circumference and an elongated element (24), having a pair of opposed internal teeth and internal curves, forming an elongated hollow to accommodate and constantly engage with the circular element. Due to their geometry and geometrical relationship, the three elements (20), (22) and (24), throughout the full cycle of reciprocating motion of the elongate element (24) and rotary motion of the drive shaft (20), remain fully engaged without interruption and with no further requirement for any additional gear engagement support. Simplicity, versatility, efficiency and easy to implement characteristics of the present invention, makes it the most practical arid effective motion conversion system of its kind.

Abstract: A fluid-operated actuator comprising a chamber part (1) with at least one chamber (12, 13), a carrier (3) which is rotatably mounted in the chamber part (1), and a plunger piston (2) in the form of a circular arc. The plunger piston can be moved along the circular arc and thereby rotate about the carrier's axis of rotation (50) since it extends in the chamber and is arranged to connect with the carrier (3). According to the invention the plunger piston (2) via a sealing device (32, 33, 42-45) is passed sealingly through an opening (14, 15) in the chamber (12, 13), there being a clearance between the surface of that section of the plunger piston which is located in the chamber and the chamber walls. Furthermore that section of the plunger piston which is located outside the chamber (12, 13) is supported along its radially outer surface by a support part (4) which is attached to the chamber part (1).

Abstract: A rotary flow control valve including a valve spool which is rotated back and forth to move a port in the valve spool into and out of alignment with the main fluid passageway of the valve to selectively open and close the valve. The spool has a pinion gear at each end of the spool and each pinion gear is engaged by a pair of racks with the racks in a pair moving at any given time in opposite directions. Each rack is constituted by spaced rack teeth formed in the side wall of a piston slidably mounted in a cylinder bore in the valve body, and the rotation of the valve spool is achieved by selective routing of pressurized fluid to the cylinder bores containing the pistons defining the racks.

Abstract: Positive adjustable flow is provided for a dual flow valve for paint dispensing or the like utilizing a sliding piston and a lost motion device in combination with an adjustable stop and wherein operating lift is provided by a single pressure source alternatively applied to a plurality of operating pistons.

Abstract: A vehicle steering control system and apparatus for controlling steering radius to prevent vehicle and surface damage and to provide improved low speed vehicle maneuverability. The steering control system and apparatus provides a first controllably limited turning radius range in relation to a first condition and a second controllably limited turning radius range in relation to a second condition. Examples of the first and second conditions include speed related conditions, such as, the actual speed of the vehicle, a selected gear of the vehicle, and manual selection of the turning radius. The system and apparatus includes a dual stroke hydraulic cylinder having a cylinder body housing a hydraulically controllable primary piston. A shaft is attached to and extends from the primary piston, projects through the cylinder body, and connects to the steering linkage of the vehicle. Hydraulic operation of the primary piston transfers forces along the shaft to the linkage.

Abstract: A fluid-powered rotary actuator for providing rotary movement between first and second external members. The actuator includes a cylindrical body with first and second ends. The body is adapted for coupling to the first external member, and a shaft extending generally coaxially within the body and supported for rotation relative thereto. The shaft having an adjustable end limit of rotation relative to the body. The shaft has an end portion adapted for coupling to the second external member to provide rotational movement between the first and second external members. An annular body insert is positioned coaxial with the body and at least partially within the body at the body first end. The body insert is formed as a separate part from the body and is adjustably rotatable relative to the body to permit adjustment of the end limit of rotation of the shaft relative to the body. The body insert is restrained by the body against axial movement relative to the body during powered operation of the actuator.

Abstract: Positive displacement vacuum pump is provided with a pump body, and a piston is positioned in the pump body with the piston being mounted for actuation by alternative linear movement. An elastic element biases the piston in a first direction, and a cam acts on a first end of the piston, with the cam being rotatably movable along an axis that is coaxial with the longitudinal axis of the piston to drive the piston in an alternating linear movement. A transverse bar is positioned between a first end of the piston and the cam, and the transverse bar is rotatably fixed but translationally guided in the direction of alternative linear movement of the piston. Additionally, the cam comprises a double surface to equally bias the transverse bar at two positions along the length of the bar.

Abstract: A miniature dual syringe-type pump assembly which has a high aspect ratio and which is remotely controlled, for use such as in a small diameter penetrometer cone or well packer used in water contamination applications. The pump assembly may be used to supply and remove a reagent to a water contamination sensor, for example, and includes a motor, gearhead and motor encoder assembly for turning a drive screw for an actuator which provides pushing on one syringe and pulling on the other syringe for injecting new reagent and withdrawing used reagent from an associated sensor.

Abstract: Multiple steam powered cylinders reciprocate to pivot arms back and forth connected to output drive shafts through one way clutches with the output drive shafts being interconnected through gears such that when one shaft is powered, the other is coasting. The inlet and outlet valves for each cylinder chamber are controlled by an actuator which instantaneously snaps the valves between open and closed positions. The power cylinders may be operated individually, in parallel or in series and as required, a valve passageway through the piston may be operated to equalize pressure. A pair of O-rings on the piston engage the cylinder wall only when the adjacent chamber is pressurized, thereby reducing drag in operation of the piston.

Abstract: A hydraulic control device comprises a valve (4) which can be moved inside a casing (1) and a stop for opening the valve at one point, the position of which may be set. The stop (6) slides in an axial housing (7) under the effect of a spring (8) and a stop screw (9). The opening position of the valve (4) may be easily set from outside the casing (1).

Abstract: A hydraulic power drive unit (36) including a linear hydraulic piston cylinder unit (64) with a set of longitudinally spaced gear teeth (84) in the form of a rack. A pinion gear (86) is operatively engaged and driven by the rack (84). A differential which may include a carrier (102), planet gears (108, 110) and sun gears (120, 122) may be driven by the pinion gear (86) to selectively transfer drive power to two separate rotary drive outputs (38, 40). A switching valve (160) may be provided which is responsive to a reversal of hydraulic supply pressure. Operation of the switching valve (160) may be limited by mechanical interference between an inhibit dog (181) and a cam surface (196) on the carrier (102). The carrier (102) may also include a separate cam surface (140) positioned for actuation of separate electrical switches (146, 148) in order to monitor position of the drive outputs (38, 40).

Abstract: A fluid-powered rotary actuator having a body with a cylindrical interior sidewall portion. A drive shaft extends generally coaxially within the body and is supported for rotation relative thereto. The shaft has a grooved, outwardly facing circumferential sidewall portion positioned within the body. A ring gear is positioned generally coaxially within the body and extends about the shaft with an annular space therebetween. The ring gear has a grooved, inwardly facing circumferential sidewall portion. The ring gear is formed as a separate part from the body and the ring gear grooved sidewall portion is formed prior to positioning of the ring gear in the body. The ring gear is fixedly attached to the body to prevent rotation therebetween by a weld between the ring gear and the body interior sidewall portion. A stop member is engaged by the ring gear. The stop member is axially located within the body to limit movement of the ring gear toward the body first end during assembly of the ring gear in the body.

Abstract: A hydraulic oil well pump drive system for driving an oil well sucker rod includes a master piston positioned within a master cylinder for axial displacement between first and second ends of the master cylinder. The master piston has a piston drive rod which extends through one end of the master cylinder. The drive rod is connected to a crank pin of an eccentric crank. A center seal assembly divides the master cylinder into a working chamber and a pressure chamber in opposite ends of the master cylinder. Each respective chamber defines a fluid volume which varies with the displacement of the master piston. The master piston displacement creates a bi-directional flow of working fluid from the working chamber. A wellhead hydraulic assembly is operably connected to the oil well sucker rod and is in fluid communication with the master cylinder working chamber to receive the working fluid flow.

Abstract: A reciprocating piston fluid powered motor which has a fluid inlet and a fluid outlet. Reciprocation of the piston is controlled by a reciprocable valve spool which communicates with the fluid inlet and fluid outlet. The valve spool cooperates with a valve slide which is shiftable on said valve spool to control spool reciprocation. Fluid flow through the fluid inlet and outlet is controlled by electrically actuated solenoid valves connected in flow communication to the fluid inlet and a park port. An electric pulse width modulating switch is connected to each solenoid valve and has a plurality of positions to enable the piston to reciprocate at continuous low and high speed as well as in an intermittent mode. The switch may also be connected to an air powered washer fluid pump to deliver cleaning fluid on command.

Abstract: A rotary motion/constant velocity linear reciprocating motion conversion device capable of converting rotary motion into a constant velocity linear motion or vice versa, and a hydraulic system which can minimize a ripple by using the above-mentioned conversion device, comprises a rotary motion part having a pair of first power transmission elements rotating at the same speed mounted to a common shaft, each element having alternatively positioned teeth capable of transmitting power. A linear motion conversion part comprises a second pair of power transmission elements each positioned adjacent to and engaging the teeth of the first elements. The second elements are each slidably mounted to a helical spline and comprise projections that engage helix grooves arranged in opposite directions along the shaft. The interaction of first and second power elements causes the linear motion of the helix shaft. The helical spline comprises a piston at each end that reciprocates within a respective cylinder.

Abstract: A pneumatic, rotary, rack and pinion actuator with counter-pressure actuated damping device. The actuator comprises first and second rack and piston assemblies reciprocable inside corresponding pneumatic cylinders, which engage on the opposite sides of a pinion and output shaft. Each rack and piston assembly is provided with an axially extending duct opening at opposite ends into a drive chamber and a counter-pressure control chamber, respectively; counter-pressure control and damping means are provided in the piston-assemblies and cylinders, comprising a throttling valve opening into the control chamber and a check valve in said ducts; a thrust pin member protrudes in the control chamber and into the duct end to open the check valve and feed in a controlled manner pressurised air from the drive chamber into the control chamber, before each rack and piston assembly reaches the end of its stroke.

Abstract: A fluid-pressure operated actuator has a body and an end cap which when telescoped in the body provides confronting grooves which receive a circlip in the form of a flexible length of wire spring. The end cap carries an O-ring seal axially only outwards of the circlip. Relative rotation between the body and end cap draws the circlip into position. A threaded plug, which may be secured to the outer end of the circlip, sealingly connects the body and end cap and may permit relative axial and angular movement.

Abstract: A reciprocating mechanism includes two cylinders oppositely extended outwards from a housings a piston slidably engaged in each of the cylinders, a cap fixed to the free end of each of the cylinders, a pair of gears rotatably supported in the housing, a pair of pinions engaged between the gears, and a pair of racks engaged with the gears respectively and secured to the pistons respectively. The pinions and the axles are rotated by the gears and the racks when the pistons move toward each other and move away from each other.

Abstract: Drive apparatus and method for converting linear motion to rotary motion to rotatingly drive the driveshaft of a motor vehicle are disclosed. The drive apparatus includes a sprocket rigidly connected to a shaft and axially aligned thereabout. In addition, a moveable ratch for moving between first and second drive positions and having opposing first and second linear sprocket engaging drive segments is provided. The first linear drive segment of the moveable ratch engages the sprocket when the ratch is in its first drive position and the second linear drive segment engages the sprocket when the ratch is in its second drive position.

Abstract: A shock absorbing apparatus comprises a cylinder body having a cylinder chamber formed therein, a piston body reciprocatively held in the cylinder chamber and having a pair of piston rods outwardly projecting through hole portions respectively formed at the two end portions of the cylinder chamber, and a shock absorber for absorbing motion when one of the piston rods projects over one of the hole portions and the leading portion of the other piston rod is stopped in the other hole portion, so that a shock generated at the time of collision with an object is absorbed.

Abstract: A linear movable apparatus for imparting rotational movement to a turntable is provided. The turntable is secured to a rotatably mounted shaft having a ring gear thereon for meshed engagement with gear teeth provided on a piston rod which extends between a pair of pistons. Each piston is reciprocally carried in aligned cylinder housings mounted in a support structure. An adjustable mechanism is provided for retaining the piston rod in snug-fitting relation with the ring gear, and a bracket assembly is secured around the ring gear to support the adjustable mechanism against the ring gear.

Abstract: Portable lift structure for moving a support platform between a comparatively dry position above the surrounding deck of a liquid spa tank to a wetting position in the spa tank including two longitudinally extending structural members pivotally connected at corresponding top ends thereof to be moved between a portable and operating positions, one structural member serving as a mast to be removably mounted in the spa tank deck and the other as a platform mount, to be pivoted from above the surrounding spa tank deck to a position above the spa tank and lowered by a hydraulic cylinder and piston to a wetting position.

Abstract: The support of a shaft (7) which is rotatably supported in through-holes of the housing (1) of a pressure chamber in bushes (11, 12) provided with sealing rings and which is secured against axial displacement by securing rings (21, 22) is to be improved in such a way that a low-wear and secure arrangement of the shaft (7) and bearing bushes (11, 12) is achieved. For this purpose, it is suggested that each through-hole (9, 10) of the housing (1) comprise a collar (15, 16) which projects radially inward and forms a support for a projection which is directed radially outward and with which each bush (11, 12) is provided, the front side (19, 20) of the latter facing the pressure chamber simultaneously forming a support for a securing ring (21, 22) arranged on the shaft (7), wherein the two bearing sides of the shaft (7) have the same diameter.

Abstract: A linear drive comprising a drive member adapted to be reciprocated axially in a housing between two end positions. Opposite to the former there is a wall on at least one axial side. There are means to reduce the impact in the end position, such means having an annular lip. The lip is arranged on the drive member or on the wall and respectively faces the wall or the housing. The lip defines a damping space which is open on an impact side. If the drive member approaches one end position thereof, the damping space is occluded and reduced in volume so that some trapped fluid will escape via a relief opening so that there is a braked part of the stroke. Using simple means it is therefore possible to provide an extremely efficient fluid damping at the end position.

Abstract: An object of the present invention is to provide a two dimensional drive system driven by fluid pressure. The drive system of the present invention comprises: a pair of X-guides; a pair of Y-guides; an X-rod whose each end is slidably attached to each Y-guide; a Y-rod whose each end is slidably attached to each X-guide; an X-piston section being provided at the midway of the X-rod; a Y-piston section being provided at the midway of the Y-rod; and a moving body having an X-chamber through which the X-rod is pierced and a Y-chamber through which the Y-rod is pierced, the X-chamber being divided into two subchambers by the X-piston section, the Y-chamber being divided into two subchambers by the Y-piston section. With this structure, the moving body is capable of moving in a plane by selectively supplying fluid to each subchamber.

Abstract: This invention relates to an assembly of a hydraulic motor and a combined device for immobilization, comprising: a reaction cam; a cylinder-block mounted to rotate with respect to the reaction cam; a first immobilization member fast with the cylinder-block; a second immobilization member fast with the reaction cam and capable of being disposed in a first position, in which the first and second immobilization means are fast with one another, and a second position, in which these first and second immobilization members do not cooperate for their mutual immobilization. The device for adjusting the relative position of the first and second immobilization members comprising a jack comprising a chamber.

Abstract: The present invention discloses an apparatus for the rotation of, for example, workpieces to be machined, on a carrier which can be set in rotation by a pinion shaft with toothed strips via a rack, the rack being arranged perpendicularly to an axis of the pinion shaft in a cylinder bore of a housing slidably between covers closing the cylinder bore, pistons provided on the rack at each end forming with a respective cover a chamber which can be subjected to pressure medium, and the toothed strips of the pinion shaft meshing with the toothing of the rack between the two pistons, wherein the spacing of the toothing and pinion shaft or toothed strips is variable.

Abstract: A 3-position actuator having a moving body comprising a piston and piston rod slidingly reciprocating in an axial direction within a casing, a part of the rod protruding from said casing, said moving body being moved to one end side when fluid flows into a first fluid chamber through a first port formed on said casing, and said moving body being moved to the other end side when fluid flows into a second fluid chamber through a second port formed on said casing; characterized by that a pair of stoppers are installed in said casing with a specified clearance left between them in the axial direction, a pair of spring seats and a spring are installed between the pair of stoppers, said spring is located between the pair of spring seats to press one spring seat against one stopper and to press the other spring seat against the other stopper, a pair of stopping portions are provided on said moving body in a projecting manner with a specified clearance left between them in the axial direction, one stopping portion ma

Abstract: A device for controlling the operating pressure between the two rotary cylinders in a machine used for processing layers such as webs, ink films, or the like for instance on an offset printing machine. The device includes a pneumatic jack having an outlet rod of a piston thereof which acts to position each bearing supporting an end of a central shaft of a cylinder. When a chamber of the jack is subjected to pressure, the rod acts against the shift of the bearing in a direction which causes an increase of the distance between the two cylinders. A fixed, though adjustable, arresting piece acts against a shift of the bearing in a direction which would cause a reduction of the distance between the cylinders.

Abstract: The tandem master cylinder comprises, in a bore, a primary piston defining with a secondary piston a primary chamber, the secondary piston defining with the bottom of the bore a secondary chamber, the primary and secondary chambers having respectively primary and secondary outlet orifices, the primary and secondary chambers being respectively associated with primary and secondary expansion holes, able to be closed respectively by the primary and secondary pistons.The method for adjusting the lost motion of the secondary piston comprises the following steps:placing the pistons and springs in the boreleaving the primary piston in contact with its rest stopmoving the secondary piston until it closes the secondary expansion holedetecting the closure of the secondary expansion holemoving the secondary piston until the secondary expansion hole just reopensdetecting the reopeing of the expansion holesetting the maximum separation.

Abstract: An apparatus (10) for providing rotary and linear motions, either simultaneously or separately. The apparatus (10) includes a rotary table assembly (14) that interconnects a rotary actuator assembly (12) and a power cylinder (18) or a comparable device. The rotary table assembly (14) includes a rotatable hub (16) to which the power cylinder (18) is mounted. Rotation of the hub (16) causes rotary motion of the entire power cylinder (18). Because of the interconnection between the rotary actuator assembly (12) and the power cylinder (18) using a rotary table assembly (14), a modular construction is provided whereby the power cylinder (18) can be positioned both vertically and laterally, depending upon the application or intended use of the apparatus (10). In one preferred embodiment, the rotary actuator assembly (12) converts linear movement to rotary motion using hydraulic oil to provide a smooth, adjustable control of the rotary shaft (32) of the rotary actuator assembly (12).

Abstract: An electro-hydraulic position-servo device to quickly and accurately position a stop element is provided for use with a positive displacement fuel injection system, wherein a shuttle is used to positively displace pre-metered slugs of fuel to unit injectors. The stop device is operatively associated with a control shaft having at least one helical surface thereon; the stop element and control shaft slidably located within a housing. The housing permits communication between at least one pressurized fluid source and a drain line by way of a chamber within which the control shaft is located. Thus, by simply rotating the control shaft from rotational drive means, the control shaft will assume an axial position determined by the orientation of the helical surface with respect to the supply and drain lines. The device is adjustable by rotation of the shaft to a new position with the re-orientation of the helical surface.

Abstract: An all-wheel steering system for motor vehicles includes an adjusting motor (10) for the rear wheels. The motor has a piston rod on which two fixed working pistons (25 and 25A) and, in a housing segment located between the working pistons, two movable steering pistons (27 and 27A) are mounted. The working pistons (25 and 25A) and steering pistons (27 and 27A) form control chambers (28 and 28A) that are constantly connected to a pump (2). Between the steering pistons (27 and 27A) is a pressure chamber (33) in which a spring element (34) acts upon the steering pistons (27 and 27A). The pressure chamber (33) can be blocked via a 2/2-way valve (37) that is controlled by a switching device (17) or it can be connected with a tank (3). When the rear-wheel steering system (11) is in the operating position, the two steering pistons (27 and 27A) come to rest against a sleeve (35) on the piston rod by virtue of the pump pressure that is fed into the control chambers (28 and 28A).

Abstract: A device for translating linear to rotary motion comprising a housing member, a rack member disposed in the housing member for longitudinal movement therein and having a starting position, a shaft in the housing having a pinion thereon engaged by the rack, the shaft being journalled in the housing and being disposed generally perpendicular to movement of the rack member, the shaft extends outwardly of the housing and has a rotative driving member thereon, the rack member has a longitudinal opening therein at one end thereof receiving the cylinder of gas cylinder-piston assembly, the piston of the gas cylinder piston assembly engages an end wall of the housing whereby upon movement of the rack member the gas in the cylinder is compressed and energy is stored therein, a slave cylinder in the housing member is adapted to receive fluid under pressure from an external source, a floating piston in the slave cylinder is arranged to act upon and linearly drive the rack and thereby rotate the pinion, the shaft and the