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: An active mount structure may include an actuator coupled to an actuator plate coupled to an orifice plate within a housing, wherein the actuator includes a plunger coupled to the actuator plate, a first rod rotatably coupled to a bottom of the plunger and rotated by a first motor unit, wherein the first rod includes a rotating shaft rotatably coupled to the plunger, one side of the rotating shaft extending to form an extending portion, and a rotation retention portion formed at the extending portion, a swash plate defining a center hole therein and having shaft protrusions, wherein the first rod may be disposed in the center hole and the rotation retention portion may be engaged to the swash plate, and a second rod engaged at the swash plate and raised or lowered by a second motor unit, wherein the shaft protrusions may be rotatably coupled to the housing.

Abstract: A method and apparatus are disclosed for selectively providing a fluid communication path between a plunger element and a contact region of an intermediate element that drives the plunger element. The fluid communication path is suitable for lubricant flow to enable a contact zone to occasionally be lubricated. The apparatus includes an elongate plunger element comprising a first end region, an intermediate element comprising a contact region arranged to selectively abut with and thereby urge a further end region of the plunger element and a spring seat member at the further end region of the plunger element. The spring seat member biases the further end region of the plunger element away from the intermediate element during a portion of a cycle of motion of the plunger element. A fluid communication path is thereby provided between an abutment surface of the further end region and the contact region.

Abstract: An active mount structure may include an actuator coupled to an actuator plate coupled to an orifice plate within a housing, wherein the actuator includes a plunger coupled to the actuator plate, a first rod rotatably coupled to a bottom of the plunger and rotated by a first motor unit, wherein the first rod includes a rotating shaft rotatably coupled to the plunger, one side of the rotating shaft extending to form an extending portion, and a rotation retention portion formed at the extending portion, a swash plate defining a center hole therein and having shaft protrusions, wherein the first rod may be disposed in the center hole and the rotation retention portion may be engaged to the swash plate, and a second rod engaged at the swash plate and raised or lowered by a second motor unit, wherein the shaft protrusions may be rotatably coupled to the housing.

Abstract: In a module system for manufacturing variants of two and three stable positions fluid-operated actuators a cylinder housing of both variants of two and three stable positions actuators is manufactured from a blank. The blank includes at least one opening for a cover and is identical for the variants of the two and three stable position actuator, and is at least prepared for the arrangement of a first pressure duct, a second pressure duct, and a first cylinder diameter of the cylinder housing.

Abstract: A proportional control pneumatic cylinder as an air actuator device for a hydraulic pump valve having a valve spool moving in a bore in a valve housing. The device having an actuator housing attachable to the valve housing and having a bore carrying a piston coaxially secured to an end of the valve spool. The device provided with spaced openings in the actuator housing which communicate with the bore therein to introduce air to act on opposite sides of the piston, and factory pretensioned biasing means for normally urging the piston and spool to a center closed position. Surface areas on opposite sides of the piston are approximately equal so that piston movement is approximately proportional to movement of an actuating lever of an air supplying pneumatic control valve over the majority of the range of travel of the actuating lever for both raised and lowered positions.

Abstract: A fluid pressure apparatus for a bicycle comprises a piston, a housing with a chamber dimensioned to receive the piston therein so that the piston can move axially, and first and second fluid ports in fluid communication with the chamber. The first and second fluid ports are located so that the piston is disposed between the first and second fluid ports when the piston is disposed in a piston home position. A first positioning element moves from a first home position towards a first direction, and a first biasing element biases the first positioning element towards the first home position. A first coupling element couples the first positioning element to move with the piston in the first direction, but the first positioning element and the piston move relative to each other when the piston moves in an opposite second direction.

Abstract: Improvements in trunnion shaft-controlled swashplate axial hydraulic piston pumps as well as hydraulic systems used in hydrostatic transmissions utilized. e.g., in zero-turn-radius (ZTR) wheeled vehicles, such as grass mowers, with one embodiment thereof pertaining to, in combination, the noted pump, devoid of any internal servo control, and a reversible power actuator, for controlling the angle of the swashplate, externally affixed to the housing containing the pump and operatively interconnected with an end of the trunnion shaft extending from the pump housing, with the power actuator being one of a rotary actuator, a fluid power axial cylinder and a rotary electronic actuator.

Abstract: A reciprocating compressor comprises a reciprocating motor (30) disposed in a casing (10), and generating a driving force; a compression unit (40) for sucking, compressing, and discharging gas by the driving force of the reciprocating motor (30); a resonant spring unit (50) for providing a reciprocating movement of the reciprocating motor (30) with a resonant movement; and at least two spring supporting frame (22,23) by which the resonant spring unit (50) is supported, wherein one of the spring supporting frames (22) is inserted into another spring supporting frame (23) for being coupled with each other. Accordingly, since an initial location of the piston (42) can be readily adjusted, a production process is simplified in producing a reciprocating compressor, and thus its productivity can be improved.

Abstract: The invention concerns a pneumatic and/or hydraulic actuator. The pneumatic and/or hydraulic actuator is one in which the run of a driving shaft, which is pneumatically operated by a piston, can vary on the basis of the insertion in the body of the actuator or at least one cylinder, so that the body of the cylinder forms a barrier along the run of the driving shaft causing the stoppage of the shaft itself.

Abstract: An apparatus includes a housing defining a chamber therein and defining an inlet port and an outlet port and a movable pressure barrier, disposed in the chamber, separating the chamber into first and second portions, the inlet port and the outlet port being in fluid communication with the first portion of the chamber. The apparatus further includes a drive spring disposed in the second portion of the chamber for urging the movable pressure barrier in a pumping direction when in a compressed state, electric means for compressing the drive spring, and a return spring disposed in the first portion of the chamber for urging the movable pressure barrier in a recharging direction when the drive spring is in an uncompressed state.

Abstract: A torque control for a hydrostatic piston pump that provides for a servo piston rod that is connected to the swashplate of the pump and connected to a servo piston within a first cavity that receives compensation pressure that urges the servo piston toward the swashplate. The servo piston has a stem that extends into a bore and is in contact with the stem of a maximum displacement piston that extends into a second cavity that is acted upon by system pressure to urge the maximum displacement piston toward the swashplate. Additionally, within the second cavity is a set of Bellville washers that surround the stem of the maximum displacement piston to limit the movement of the maximum displacement piston toward the swashplate.

Abstract: The invention relates to a piston unit having a captive spring for a cylinder, particularly for a tandem master cylinder of a motor vehicle, wherein the spring, with a first end, is supported at least indirectly on a piston and, with a second end, is supported on a retaining device that can be displaced relative to the piston, and the movement of the retaining device relative to the piston is limited by securing means. The invention is characterized in that the securing means have a projection, which is mounted in a non-detachable manner on the piston and whose free end is provided with a stop that limits the movement of the retaining device relative to the piston.

Abstract: A three position fluid powered actuator having a piston reciprocally positioned within a cylindrical chamber in a body. The piston has a socket in communication with an axial opening through the piston. A piston shaft has a first end passing through the axial opening and into the socket and has a second end passing through a spring chamber in the body. A compression spring surrounds the piston shaft in the spring chamber. A pair of fluid passageways extend into the cylindrical chamber, whereby fluid pressure in a first passageway will move the piston in a first direction and fluid pressure in a second passageway will move the piston in a second direction.

Abstract: A pusher which has a stroke shorter than that of a piston at either position on a head side or a rod side in a cylinder main body and which serves as both means for pushing the piston from a stroke end back to an intermediate stopping position and means for stopping the piston at the intermediate stopping position is disposed so as to be movable independently from the piston, and pressing means for causing the pusher to displace to the intermediate stopping position is provided.

Abstract: Disclosed is a diaphragm-based spring brake actuator assembly which allows for the delivery of more force to the push rod without increasing the size of the actuator unit. The invention allows for the use of a stronger heavy main compression spring in the emergency brake chamber to provide greater emergency or parking brake force to the push rod. The invention also allows the service brake chamber to operate more efficiently when braking pressure is introduced. These functions are accomplished through modifications in the design of the actuators which allow for the deployment of a larger pressure plate inside either the emergency housing or the service brake housing, or both, allowing delivery of more force to the push rod of the actuator; and are made possible in actuator units having the same dimensional profile as existing weaker units.

Abstract: A zeroing mechanism for a hydrostatic piston/cylinder unit (1), has an actuating piston (2) that can be moved from a zero position N into at least one deflected position A and can be returned to its zero position N by a zeroing force, the zeroing force being produced at least in part hydraulically.

Abstract: The present invention relates to a spring supporting structure of a linear compressor which is capable of reducing the horizontal length of the compressor by reducing the overall length which adds the length of an inner resonance spring to the length of an outer resonance spring by placing at least three inner resonance springs and outer resonance springs so as to cross each other to the cylindrical direction vertical to the center line of a inner/outer spring supporters placed between an inner stator assembly and an outer stator assembly fixedly formed on a frame elastically installed inside of a casing in order to make the magnet assembly perform the linear reciprocating motion, and placing the part of the elastic region of the certain inner resonance spring so as to overlap with the elastic portion of the adjacent outer resonance spring.

Abstract: In an axial piston motor having a drive shaft, an inclined plate, and an adjusting device for the inclined plate, and at least one adjusting control cylinder with control piston adapted to establish pressure contact and to cooperate with the inclined plate and having a closed face and being formed as an inwardly open cylinder having an open end, a coil spring disposed within the inwardly open cylinder and pressing against the closed face, a sliding bush having two ends, one end thereof ranging into the inwardly open cylinder and having a flange at its opposite end and having different operating positions, one end of the coil spring resting against the flange, with the coil spring biasing the flange away, the improvement which comprises a rod connected to the closed face of the control piston, the sliding bush being formed as a hollow cylindrical sliding object having an inside diameter guided upon the rod.

Abstract: A linear compressor including: a cover fixed at a rear side of a frame; a cylinder fixedly installed in a horizontal direction at the center of inside of the frame; an inner stator assembly fixedly installed at the frame in a state that its inner circumferential surface contacts an outer circumferential surface of the cylinder; an outer stator assembly fixedly installed at the frame, being spaced apart from the inner stator assembly to the outer periphery for a predetermined distance; a magnet assembly incorporated with a piston, making a linear reciprocal movement with one end portion thereof inserted in the gap between the inner stator assembly and the outer stator assembly; at least one inner resonance spring supported by the magnet assembly; and a plurality of outer resonance springs supported between the magnet assembly and the cover.

Abstract: A zeroing mechanism for a hydrostatic piston/cylinder unit (1), has an actuating piston (2) that can be moved from a zero position N into at least one deflected position A and can be returned to its zero position N by a zeroing force, the zeroing force being produced at least in part hydraulically.

Abstract: An electromagnetic reciprocating compressor has a body (1, 2), a piston (10) reciprocating in the body, and an electromagnetic drive (22, 23, 24) for the piston. The piston has a piston head (11) which slides in a cylinder (12) in the body to effect compression of fluid in the cylinder during operation of the compressor and, axially spaced from the piston head, a piston guide member (13) slidingly movable on a guide surface (14) provided by the body. The compressor has a compression spring arrangement (20) comprising at least one helical compression spring (20a, b) acting to drive the piston axially. The spring (20a, b) is mounted around the piston and is at least partly located within the cylinder during at least part of the piston stroke but is outside the working volume of fluid undergoing compression.

Abstract: An actuator for a gear shifting mechanism of a motor vehicle has a housing with pressure chambers and one connector opening into each pressure chamber for supplying a pressure medium into the pressure chambers. A control member is positioned in the housing so as to be axially displaceable in the housing by the pressure medium into different switching positions. A first and second auxiliary piston are supported on the control member and displaceable relative to the control member by the pressure medium. The first auxiliary piston has a first end facing away from the second auxiliary piston, the first end of the first auxiliary piston having a first abutment. The second auxiliary piston has a first end facing away from the first auxiliary piston, the first end of the second auxiliary piston having a first abutment. The first auxiliary piston delimits at least partially the first pressure chamber and the second auxiliary piston delimits at least partially the second pressure chamber.

Abstract: An actuator system (31) for controlling engagement and disengagement of an automated vehicular master clutch (C). The system includes an electric motor (86) controlled actuator (62) for precision positioning of the clutch and a pneumatically controlled override actuator (54) for rapidly disengaging the clutch, regardless of positioning of the electric motor-controlled actuator. Both the electric motor-controlled actuator and the pneumatically controlled override actuator are operated in accordance with command output signals from a system control unit (31).

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: A fluid pressure actuator assembly (44) adapted for use with a valve member (42) is disclosed, the actuator being of the type comprising a housing assembly (50), and an axially moveable diaphragm assembly (56). A linkage member (48) is operably associated with said diaphragm assembly and extends axially through a linkage opening (70), and is connected to a valve member (42). A preload member (74) includes a generally annular preload portion (76) between a stop surface (55) and the diaphragm assembly (56), and in engagement with both. The preload portion (76) maintains the diaphragm assembly (56) in a position corresponding to a first position of said valve member (42), in opposition to the force of a biasing means (68).

Abstract: A run-up control for the pressure cheek in a drawing apparatus achieves stoppage times during the run-up phase by having a pressure cylinder with first and second pressure spaces as well as a control piston which is fixed in its position in the control cylinder when the second pressure space is acted upon with pressure. The control piston is fixed in its position by a piston rod, a fixed stop and an adjustable stop. The first pressure space is in a continuous flow connection with a mash pressure space which is reduced when the pressure cheek runs up so that the volume of the second pressure space determines the point in time of the stoppage time in the run-up phase of the pressure cheek.

Abstract: The camshaft tends to change in reaction to pulses which it experiences during its normal operation, and it is permitted to change only in a given direction, either to advance or retard, by selectively blocking or permitting the flow of hydraulic fluid, preferably engine oil, through the return lines (194,196) from the recesses (132a, 132b) by controlling the position of a spool (800) within a valve body (798) of a control valve (792) in response to a signal indicative of an engine operating condition from an engine control unit (808). The spool is centered during normal operation when the hydraulic loads acting on its opposed ends by the action of springs (802, 804) that also act on the opposed ends of the spool are in balance. During periods of operation when system pressure is low, a biasing mechanism forces the spool to its full advance position.

Abstract: A variable displacement radial ball pump (11) is disclosed of the type in which the balls (59) are restrained by a cam ring (25), which is pivotable about a cam pivot pin (27) to vary the displacement of the pump. In accordance with the invention, in order to return the pump to absolute zero displacement, the pump is provided with a detent mechanism (65;83). The cam ring 25 has a neutral region (73) and a ramp surface (77), and a detent member (69;89) is biased into engagement with the neutral region when the cam ring is in neutral (FIGS. 2 and 3). When the cam ring is displaced from neutral, the detent member engages the ramp surface, against the bias force of a spring (71;91), which exerts a force tending to return the cam ring to neutral in the absence of an input to the control assembly (33).

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: Presented is an air cylinder apparatus including a control mechanism that is operable to interject mechanical dead-stops to control the linear translation of the piston of the air cylinder to predetermined increments of travel.

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: The present invention discloses a linear unit, especially an apparatus for the machining, transportation and manipulation of workpieces, with a housing and with a carriage which is movable out of the housing and to which a handling appliance or the like for the workpiece can be fixed, wherein the carriage is designed as a box section and is mounted slidably in the housing on an adjustably positioned ball bearing assembly, and a groove fixing a stop member of the carriage with a shock absorber being removable from a path of the stop for cushioning of the carriage.

Abstract: The invention concerns a tilt correction system with at least one pair of cylinder and piston assemblies which are hydraulically operated. The extent of tilt correction is limited by grooves internal to the cylinders of the assemblies which short hydraulic potentials once the pistons of the assemblies have moved from a rest position to a position adjacent the grooves. A preferable arrangement includes connecting each assembly between an anti-roll bar and an axle.

Abstract: A brake motor subassembly comprises a control piston (10) having an internal cavity delimited by a base wall (18) and, at the periphery, by a stepped bore (20, 22, 24) and having a mechanical actuating device acting on the control piston via an automatic compensation device formed by a screw-nut device (34) stressed towards the base wall, via a washer (26) and an axial thrust ball bearing (32), by a resilient member (28) supported on a ring (30) fixed at the end of the control piston axially opposite the base wall, and a pilot piston (44) having a first cylindrical peripheral surface of larger diameter (46) sealingly slideably cooperating with an end of reduced diameter (20) of the stepped bore and, in the vicinity of its end (50) axially opposite to the first peripheral surface (46) and cooperating with the washer (26), a second peripheral surface of reduced diameter (54) sealingly slideably cooperating with an annular seal (38) associated with a retaining washer (40) resting axially against a shoulder (42)

Abstract: 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 or HIGH to NEUTRAL by releasing the respective charge of compressed air thereby permitting a spring to shift the control lever to neutral. Thus, in the event of a failure of the system supplying the compressed air, the actuator will return the transfer case to NEUTRAL as required for towing.

Abstract: Pump units comprising a metering reciprocating pump with adjustable length of stroke are used in packing machines for filling of packing containers with a metered quantity of flowable contents, e.g. yogurt. Adjustments in the length of stroke in order to adapt the amount of filling goods to the volume of the packing container interferes with the breaking sequence at the extreme position of the piston and alters the time for each pumping stroke. These drawbacks are avoided by means of an arrangement which includes a movable braking device for the piston as well as a valve arrangement which is linked to the braking device and serves to adapt the speed of the piston to the length of stroke.

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 control system and method for chemical injectors includes a controller which outputs multiple feed set point signals and associated driver signals, each set point signal defining a desired injection capacity for a chemical injector and the associated driver designation signal designating the injector to receive the set point signal. A driver assembly is associated with each injector. The driver assembly receives a capacity signal from the injector which defines the volumetric injection capacity of the injector, compares the capacity signal to the feed set point signal, and outputs a drive signal to adjust the volumetric injection capacity of the injector. An adjustment assembly is provided for receiving the drive signal and positioning a stop to limit the reciprocal motion of the piston of the injector, thereby adjusting the volumetric injection capacity of the injector.

Abstract: The present invention is directed to a self-adjusting servo mechanism (10). That is, the servo pin (30) presented from the servo mechanism (10) will protract sufficiently to effect operative engagement of a friction band assembly (13) with a rotating member (18) in a planetary gear set--even though the required axial displacement of the servo pin (30) during such protraction may exceed the axial displacement available to the actuating piston (33). The servo mechanism (10) is incorporated in a housing (20). The housing (20) presents a socket cavity (24) within which an actuating piston (33) is received for axial displacement through a predetermined distance. The servo pin (30) is supported by the housing (20) for axial reciprocation, and a coupling means (35) is interposed between the servo pin (30) and the actuating piston (33) operatively to protract the servo pin (30) in response to displacement of the actuating piston (33).

Abstract: A pneumatic piston/cylinder unit comprises primary and secondary pistons operable in first and second cylinder zones respectively. Each of the primary and secondary pistons divide its respective cylinder zone into two chambers, one of the chambers of the first cylinder zone being connected to one of the chambers of the second cylinder zone via a passageway which includes at least one control for the flow of hydraulic fluid therethrough. A tertiary piston is provided in the one chamber of the first cylinder zone and divides that chamber into two parts, one of which is between the primary and tertiary pistons. In use the passageway, the one chamber of the second cylinder zone and the other part of the one chamber of the first cylinder zone are filled with hydraulic fluid. Application of pneumatic pressure to the other chamber of the first cylinder zone causes the primary piston to be displaced until it abuts the tertiary piston whereupon movement of the primary piston may be arrested or controlled.

Abstract: A hydraulic system for operating the rollers and one or more steam chests in a laundry flatwork ironer. A two-way, variable delivery, high pressure, main pump operates a hydraulic motor driving the ironer rollers. A one-way, fixed delivery, charge pump keeps the hydraulic circuit between the main pump and the hydraulic motor fully charged. The charge pump also powers a hydraulic control circuit for the main pump and controls the operation of steam chest lift cylinders. The control circuit for the main pump has a positioning cylinder and a speed control cylinder which jointly control the direction and delivery rate of the main pump, thereby controlling the direction and speed of the ironer rollers. The control circuit has a solenoid valve for stopping the hydraulic motor in an emergency and a solenoid valve for selectively controlling the speed of the chest lift cylinders.

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: A hydraulically operating actuating device for a lift valve, in particular in an internal combustion engine, has a piston which is connected to the valve stem. The piston is positioned in a cylinder and separates two stroke spaces which are connectable, in each case via inlet and outlet openings which can be occluded by the piston, to a pump for the working fluid or a reservoir. In order to reduce the energy requirement of the actuating device, the two inlet openings, which in a central actuation range of the piston are open, are connected to one another directly by a line, and two springs which act in opposite directions and, in equilibrium, hold the piston in a central position relative to two end positions engage on the piston or valve stem.

Abstract: An adjustable axial piston machine is disclosed which has a housing, a cylinder drum and an operating cylinder-servo piston unit capable of being acted upon by control pressure. The cylinder-servo piston unit has a movable part which is being connected with a control of the axial piston machine. The operating cylinder-servo piston unit has an annular configuration and is located around the cylindrical drum.

Abstract: A fluid motor actuator of the type in which an actuator member is moved in either one of two opposite directions from a rest position to an actuated position includes a fail-safe mechanism having compression springs coupled with the actuator member for compression of the compression springs in response to actuation of the actuator member in either of the two opposite directions for establishing a restoring force which, upon loss of motive power, will return the actuator member to the rest position and maintain the actuator member in the rest position pending restoration of motive power.

Abstract: A control arrangement is provided which permits precise metering of a bellows pump. The control arrangement permits the predetermined setting of an amount of fluid to be dispensed from a single pump or a plurality of pumps. The control system permits a double bellows pump to cooperate with a drive mechanism in order to precisely meter the fluid to be dispensed from the pump by selecting a predetermined amount of fluid from a range of settings of the control mechanism. When a plurality of double bellows liquid dispensing pump units are provided, a plurality of electric motors are arranged to drive an adjustable stop element and provide a limit on the length of stroke of a driving rod connected to the bellows pump. The motors are controlled by a program logic circuit which monitors the degree of movement of the stop elements and controls the motors in response to a preset or selected fill condition.

Abstract: A biasing force adjusting apparatus is used for an electromagnetically driven reciprocating pump in which the piston is reciprocated to achieve pumping by a magnetic force cyclically generated from an electromagnet and a biasing force of a compression coil spring. The apparatus includes a pressing mechanism having a piston-cylinder unit to which a compressor is connected. The unit is detachably connected to a spring support to press the support at a predetermined pressure, and then a fixing screw is tightened to fix the support on a housing of the pump.

Abstract: Apparatus for incremental cylinder length control in hydraulic seismic vibrators having increased frequency range. The vibrator apparatus (10) of the type having a reaction mass (38) and axial cylinder bore (42) utilizes hydraulically movable end sleeves (86 and 96) in each end of the cylinder bore (42) so that the end sleeves (86 and 96) can be controllably positioned thereby to alter the cylinder volume and adjust the hydraulic drive system (18) for maximum efficiency relative to operating frequency.