Abstract: A bulk handling system for collecting, loading, transporting and dumping of yard waste and landscape materials such as grass clippings, yard debris, soil, mulch, stone and other dry and/or wet substances. The functions for controlling and operating the mechanical bulk handling system include a titling lift platform for filling and dumping and a gate that when open acts as a lift to move materials into the bulk container and when closed functions as a closed door. In addition to the bulk container operating in a horizontal position for transporting, which uses virtually no floor space on the platform and/or vehicle selected for use, it can also be angled downward for filling and elevated for dumping and emptying. For filling, the gate end of bulk container and lift frame can be lowered closer to the ground from a vehicle for easier and more efficient loading by an operator.

Abstract: A clutch actuating device includes an actuating cylinder having a piston, a multiplier cylinder, and at least one rod extending from the multiplier cylinder to the piston of the actuating cylinder. The actuating cylinder has a rod-side chamber and a clutch actuation chamber with the piston extending therebetween. The rod-side chamber has a port for connection to a first pressure source, and the clutch actuation chamber has a port for connection to a slave cylinder of a hydraulic clutch. A passage interconnects the rod-side chamber with the clutch actuation chamber, and a check-valve is located in the passage. The check-valve only permits flow between the rod-side chamber and the clutch actuation chamber for purposes of compensating for changes of volume of fluid due to temperature change and only when the piston is retracted to an idle position.

Abstract: An electrical connector system for use with independently heated hoses includes a first electrical connector, a second electrical connector, a third electrical connector, and a fourth electrical connector. The first electrical connector includes a first key that mates with a second key of the second electrical connector. The third electrical connector includes a third key that mates with a fourth key of the fourth electrical connector. The first and second keys differ from the third and fourth keys, ensuring the electrical connectors are correctly connected.

Abstract: An apparatus for removing rubber stator material from inside a housing includes a head, at least one blade, and an actuator. For example, the apparatus can be used to core out rubber material from the housing so new material can be molded therein. Also, the apparatus can be used to cut back excess rubber material newly molded in the housing. The head is rotated about an axis and is moved along the axis relative to the housing. The at least one blade is pivotably connected to the head and removes the rubber stator material at least partially from inside the housing with the rotation and movement of the head through the housing. The actuator is associated with the at least one blade and is operable to adjust a pivot of the at least one blade relative to the head.

Abstract: Drivers and drive systems (e.g., off-axis drive systems, pneumatic motors, multi-gear drive systems, and/or the like), and kits comprising drivers with drive systems, such as those, for example, configured to move a drive shaft.

Abstract: An improved power steering assembly is provided. The power steering assembly includes an end-of-travel mechanism and a valve cartridge that is actuated by left and right actuator rings of the end-of-travel mechanism, the actuator rings extending partially around an output shaft. The actuator rings can be individually set for the desired end-of-travel relief to limit the maximum system pressure when the steering assembly approaches the desired axle stop setting. The valve cartridge provides an end-of-travel function and a pressure relief function and is in fluid communication with the left and right pressure chambers to recirculate hydraulic fluid in the event of a power off condition.

Abstract: In a power steering system employing an end of travel system including valve actuating rings disposed about a Pitman arm shaft, a device is provided for setting the positions of the rings on the shaft. The device includes a fixed member positioned about, and fixed against movement along, a longitudinal axis perpendicular to the shaft's rotational axis and a movable member that moves along the longitudinal axis relative to the fixed member. The movable member defines a pin at one end configured for engagement with the circumferential ends of the actuating rings. A positioning force applied to one of the members causes the movable member to move between set and reset positions in which the pin engages corresponding ends of the actuating rings during rotation of the shaft and a running position in which the pin remains disengaged from the ends of the actuating ring during rotation of the shaft.

Abstract: A self-setting valve assembly for a power steering gear assembly includes a plug, a first plunger, a second plunger, and a biasing member. The plug extends between a first end and a second end. The plug defines a cavity that is disposed between the first end and the second end, a first bore that extends from the first end to the cavity, and a second bore that extends from the second end to the cavity. The first plunger has a first head that is disposed within the cavity and a first stem that extends from the first head through the first bore. The second plunger has a second head that is disposed within the cavity and a second stem that extends from the first head through the second bore. The biasing member is disposed within the bore and extending between the first head and the second head.

Abstract: An actuating cylinder for an adjustment apparatus of a pivot angle of a hydrostatic axial piston machine has a hydraulic stop which connects an actuating pressure chamber of the actuating cylinder to an interior of the housing of the axial piston machine if the actuating piston is maximally extended. To this end, a channel is provided on the actuating piston side, while a control edge is provided on the housing side. The control edge is formed at the interface of a stop bore with the actuating cylinder bore. The stop bore may also be a leakage bore of the axial piston machine.

Abstract: A piston (6) is hermetically inserted via a sealing member (7) in a cylinder hole (2) provided in a housing (1) so that the piston (6) is movable in an up-down direction. A communication passage (21) provided in an inner peripheral wall of the cylinder hole (2) is communicatively connected to a lock-side supply and discharge passage (13) through which pressurized oil is supplied to and discharged from a lock chamber (11) of the housing (1). An opening area (S1) of the communication passage (21) is designed to be smaller than an opening area (S2) of the lock-side supply and discharge passage (13). When the piston (6) is caused to move for releasing from a raised position to a lower limit position, the sealing member (7) is lowered from the raised position beyond the communication passage (21), to open communication between a release chamber (12) in the housing (1) and the lock-side supply and discharge passage (13) via the communication passage (21).

Abstract: A double-acting overflow valve of a working cylinder includes a housing with an encompassing wall and a first and a second axial delimiting wall disposed opposite one another. A first valve body has a first valve tappet with a conical shape and passes through the first axial bore to define a first annular gap with a gap width that is dependent on a position of the first valve body along an actuation path thereof. A second valve body has a second valve tappet with a conical shape and passes through the second axial bore to a second annular gap with a gap width that is dependent on a position of the second valve body along an actuation path thereof. A first and second counter bearing are provided. A first actuating element defines a maximum actuation path of the first valve body by acting on the first counter bearing. A second actuating element defines a maximum actuation path of the second valve body by acting on the second counter bearing.

Abstract: An actuator is disclosed comprising: a moveable member; a first hydraulic chamber in contact with a first surface of the moveable member; a second hydraulic chamber in contact with a second, opposing surface of the moveable member; a movable locking mechanism coupled to a moveable wall of the second hydraulic chamber; and a resilient biasing member acting on the moveable wall of the second hydraulic chamber so as to bias the moveable wall and locking mechanism. The actuator is configured to selectively vary the pressure in the second hydraulic chamber so that the resilient biasing member is able to bias the moveable wall to move, thereby moving the locking mechanism to engage the moveable member so as to prevent the movement of the moveable member towards at least one of the first and second hydraulic chambers.

Abstract: A phaser valve for a piston and cylinder assembly helps to keep a pair of pistons in phase with each other. The phaser valve includes a poppet which is slidable between opposing seats of a valve housing. The poppet includes a head and a stem, both the head and the stem having concave portions which facilitate the flow of hydraulic fluid across the valve. The poppet head has two generally conical ends, so that the head makes a fluid-tight seal with a seat when the head is urged towards either seat. Due to its construction, the phaser valve may be built to fit within a very small space, while still allowing a substantial flow of fluid when the head is not in abutment with one of the seats.

Abstract: A device automatically mixes bone cement and has two separate plunger space sections with a gas feed and a gas outlet, which are separated from each other through a plunger. A blocking organ is provided in the plunger and can be switched at the turnaround points of the plunger path. Suitable connecting facilities connect the plunger to a mixing facility that is arranged in a mixing vessel. Alternating build-up of a pressure difference and pressure equalization in both plunger space sections causes the plunger to move up and down. The plunger motion effects a simultaneous up-and-down motion and rotation of the mixing facility.

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

Abstract: A fluid pressure operated actuator device, comprising: a body defining a first chamber (2) comprising an inlet in fluid communication with a pressurized fluid source (1); and a moveable element (5) mounted in the first chamber, the moveable element comprising an operative end (4) and partition means (3) configured to separate a first region of the first chamber comprising the inlet from a second region of the first chamber opposed to the first region during use of the device, the moveable element being moveable relative to the body between an extended configuration and a retracted configuration, with movement from the retracted configuration to the extended configuration occurring in response to a pressure differential across the partition means, wherein the actuator device includes a first passageway (7) for allowing passage of fluid from the pressurized fluid source to a second chamber (9) in the operative end of the moveable element, and a second passageway (8) for allowing passage of fluid from the second

Abstract: A phaser valve for a piston and cylinder assembly helps to keep a pair of pistons in phase with each other. The phaser valve includes a poppet which is slidable between opposing seats of a valve housing. The poppet includes a head and a stem, both the head and the stem having concave portions which facilitate the flow of hydraulic fluid across the valve. The poppet head has two generally conical ends, so that the head makes a fluid-tight seal with a seat when the head is urged towards either seat. Due to its construction, the phaser valve may be built to fit within a very small space, while still allowing a substantial flow of fluid when the head is not in abutment with one of the seats.

Abstract: The present invention provides a three position hydraulic piston assembly for a gear ratio change mechanism for a transmission exhibiting reduced gear shift noise. The three position hydraulic piston assembly includes a master piston and motion retarding assemblies that act near both travel limits of the master piston. The master piston includes symmetrical passageways that provide hydraulic fluid flow to small chambers at each end of the piston that are closed off as the piston approaches its travel limits. Hydraulic fluid trapped in the chambers decelerates the piston and is bled off through an orifice allowing the piston to reach its travel limit and quickly and quietly engage a gear ratio.

Abstract: Disclosed is an apparatus for protecting impact to a rack bar of a power steering gearbox comprising an oil pressure cylinder, to which oil which has passed through an oil pressure pump and a rotary valve is supplied through a left port or right port, a rack bar disposed in the oil pressure cylinder and horizontally reciprocating, a piston fixed at the middle of the rack bar, a first lack bush and a second lack bush disposed at both ends of the cylinder, in which the piston moves, to close the cylinder, and bypass holes with a downward convex shape disposed at both ends of the cylinder adjacent to the first and second rack bushes, in which a part of oil pressure is released immediately before a piston of the rack bar moving by the power of oil pressure reaches a rack bush, whereby impact to the cylinder or noise is not generated.

Abstract: A pressure releasing valve structure 36? is provided for a fluid operated device 10. The device has an orifice 42 constructed and arranged to be in fluid communication with a pressure chamber C. The valve structure includes a body 49 having first and second ends. A valve member 40 is provided at the first end of the body and is constructed and arranged to seal the orifice 42. A first spring 38 is associated with the first end of the body and is constructed and arranged to cause the valve member 40 to seal the orifice 42 under first pressure conditions in the pressure chamber C. A second spring 50 is associated with the second end of the body and is constructed and arranged to compress thereby reducing a force exerted by the first spring 38, permitting the valve member 40 to move to a non-sealing position to open the orifice under pressure conditions in the pressure chamber C lower than would be required absent the provision of the second spring.

Abstract: An under body hydraulic cylinder is disclosed having a poppet relief valve disposed through a piston. As the piston is moved by oil pressure towards the stuffing box, the poppet relief valve engages a stroke stop mounted on a stuffing box surrounding the piston rod. As the poppet engages the stroke stop, the poppet is opened to allow oil to bypass the piston. The cylinder stroke is determined by the length of the stroke stop mounted on the stuffing box.

Abstract: A hydraulic shutoff device in the end positions of a servo cylinder is provided to prevent direct hard contact between the working piston (31) and the limit stops (47, 48) under working pressure and to enable withdrawal from end positions with hydraulic assistance. Idler pistons (32, 33) with limited displaceability are located on the working piston (31) and act as a seal, fitting tightly against the sealing edges (34, 35) of the working piston. The sealing edges (34, 35) control a bypass channel (36) located in the working piston (31). A spring (41) is inserted between the idler pistons (32, 33) in a chamber (40) which can be pressurized. When the working piston (31) comes into contact, for instance, with the limit stop (48) of the bush (43), the collar (45) knocks one idler piston (33) away from the sealing edge (35). Junction with the chamber (40) occurs through the bypass channel (36), whereupon the working pressure pushes the idler piston (32) back against the spring (41) away from its sealing edge (34).

Abstract: A hydraulic power steering gear assembly includes an assembly body defining a piston chamber having opposed chamber ends with plunger passages formed in the ends, a reciprocating piston and a chamber having opposed ends and a passage extending between the piston ends, a check valve at each end of the piston passage, and a plunger assembly in each plunger passage with each assembly including a spring frictionally holding assembly in the passage and a poppet extending into the chamber to unseat a ball valve as the piston is moved toward one end of the chamber.

Abstract: A hydraulic power steering gear assembly includes an assembly body defining a piston chamber having opposed chamber ends with plunger passages formed in the ends, a reciprocating piston and a chamber having opposed ends and a passage extending between the piston ends, a check valve at each end of the piston passage, and a plunger assembly in each plunger passage with each assembly including a spring frictionally holding assembly in the passage and a poppet extending into the chamber to unseat a ball valve as the piston is moved toward one end of the chamber.

Abstract: A novel adjustment assembly for use with a hydraulic control apparatus. The hydraulic control apparatus is attached to a hydraulically operated tool to provide a desired hydraulically powered function. The present invention allows the hydraulic control apparatus to be used with either a constant volume (open-center) hydraulic system or constant pressure (closed-center) hydraulic power system. The novel adjustment assembly of the present invention provides a structure which can be configured to force open shuttle spool valves in the control apparatus in a neutral condition for use with a constant volume power supply. The adjustment assembly can also be configured to be disengaged from the shuttle spool valves in a neutral condition for use with a constant pressure hydraulic power system. Operation of the adjustment assembly is made using standard tools and without disassembly of the control apparatus.

Abstract: A linkage mechanism which allows a substantially 180.degree. pivoting motion of a frame, and hence a boom arm secured to the frame, around the frame's pivot axis includes a mast to which the frame is fixedly secured, the mast being pivotably mounted on a pivot axis to an associated support frame. First and second hydraulic cylinders, each having a piston rod end and a cylinder end, are connected to respective sides of the mast. A control member is operatively associated with the first and second hydraulic cylinders for effecting a linear movement of the piston rods thereof and hence a pivotal movement of the mast and thus the boom arm secured to the mast about the mast's pivot axis. An overload protection circuit is connected to at least one of the first and second hydraulic cylinders such that the mast, and the frame and boom arm, will pivot around the pivot axis in the event an associated tool secured to the boom arm meets an obstruction. This avoids damage to the associated tool as well as the boom arm.

Abstract: The main feature of the differential pressure detecting system of the present invention resides in that, when a mechanical arm is to clamp a workpiece, a differential pressure can be produced for operating a cylinder and in turn triggering a responsive switch to activate a display device; when it clamps the workpiece, the differential pressure still exists for maintaining the said activating, when it clamps nothing, the cylinder will be restored and in turn turn off the responsive switch to turn off the display device.

Abstract: An apparatus (10) including a housing (14) defining a chamber (16) and a movable piston (18, 100) dividing the chamber (16) into first and second chamber portions (20, 22). An apparatus (38, 40) directs fluid pressure into either the first or second chamber portion and vents the other to effect movement of said piston (18, 100). A relief valve (12) communicates the first and second chamber portions (20, 22) when the piston (18, 100) is near the end of its work stroke. The relief valve (12) includes a valve member (76) and a valve seat (74) which are relatively movable between open and closed positions. A method is performed to make the apparatus and includes forming a press-fit connection between the piston means (18, 100) and the valve seat (74).

Abstract: A clip valve for limiting the stroke of an exhaust-valve-operating hydraulic actuator piston in a compression release engine brake has a plunger which follows the actuator piston down until the motion of the plunger is stopped by a retaining ring in a bore in which the plunger reciprocates. When the plunger is thus stopped, an aperture in the slave piston is uncovered, thereby allowing pressurized hydraulic fluid to escape from the actuator piston cylinder and preventing further downward motion of the actuator piston. The clip valve apparatus is constructed to facilitate assembly of the plunger and retaining ring in the bore, as well as to provide secure and fail-safe retention of those components in the bore. The parts of the clip valve are simplified and preferably also reduced in number as compared to the prior art.

Abstract: This invention relates to a pressure turnoff device in the terminal positions of the steering deflection in an auxiliary power steering. In steering systems that reveal a working piston (2) that can be shifted in the steering housing, one inserts this turnoff device in a passage borehole (17) of working piston (2). For each steering direction, one provides a turnoff valve (20, 22 or 21, 23) which can be activated by a plunger (24 or 25) that bumps into a wall (30 and 31). To avoid any time consuming adjustment work on the turnoff valves (20, 22; 21, 23), the walls (30 and 31) contain screwed-in bolts (40 and 41) with pressed-on sleeves (32 and 33), with the sleeves working as stops. After installation of the auxiliary power steering in the vehicle, one can automatically press the sleeves (32 and 33) into the terminal position corresponding to the wheel steering angle.

Abstract: A linkage mechanism which allows a substantially 180.degree. pivoting motion of a frame, and hence a boom arm secured to the frame, around the frame's pivot axis includes a mast to which the frame is fixedly secured, the mast being pivotably mounted on a pivot axis to an associated support frame. A first hydraulic cylinder having a piston rod end and a cylinder end is pivotably secured at the piston rod end to a first side of the mast. A second hydraulic cylinder having, a piston rod end and a cylinder end is pivotably secured at the piston rod end to a second side of the mast. A control member is operatively associated with the first and second hydraulic cylinders for effecting a linear movement of the piston rods and hence a pivotal movement of the mast and thus the boom arm secured to the mast about the mast's pivot axis.

Abstract: A device comprising a cylinder and a piston slidably fitted therein and having a metal piston ring attached to its outer periphery. The cylinder has a recess in each of a plurality of portions thereof dividing the inner periphery of the cylinder circumferentially thereof and opposed to the piston ring when the piston is brought close to each of its opposite stroke ends, the recess having a width smaller than the width of fit of the piston to the cylinder. The piston has a recess corresponding to the recess in the cylinder inner periphery and formed in each of a plurality of portions of the piston in the vicinity of the piston ring and diving the outer periphery of the piston circumferentially thereof. The cylinder has two oil chambers formed on the respective opposite sides of the piston and adapted to communicate with each other through the cylinder recess and the piston recess upon the piston being brought close to each stroke end.

Abstract: The invention relates to an auxiliary power steering system, especially for motor vehicles having a double acting servocylinder with two working chambers and a servopiston. A hydraulic steering limitation device has a valve that coacts with the servopiston responsive to a predetermined extent of power stroke to open a flow path from the pressurized working chamber to the tank connected working chamber to promptly stop the power stroke leaving the servopiston in position for prompt reversal of steering direction under pressure power. A stationary flow channel member extends the substantial length of the servocylinder and passes through a bore in the servopiston with which it has a sliding relationship. At a predetermined end of a power stroke, bores and a passage in the channel member communicate with the working chambers of the servocylinder to equalize the pressure at tank pressure for stopping the power stroke.

Abstract: A piston assembly comprising a primary piston and a co-centric secondary piston. The pistons are received within a housing for reciprocating movement therein and relative to each other. The housing and the pistons are arranged for operating pressure to be applied to the secondary piston so as to drive both pistons within the housing. The secondary piston is provided with means enabling the operating pressure to be equalized across the secondary piston and at least one bypass passage extends through the secondary piston. The arrangement is such that upon completion of the stroke of the pistons pressure equalization occurs across the secondary piston which causes the pistons to separate. The bypass passage becomes fully operable subsequent to pressure equalization, whereby a fast return stroke is achieved.

Abstract: A hydraulic vehicle brake system of the type having a high system return pressure is provided. In order to minimize the size and strength of brake return springs required, the invention provides a device to be interposed between the brake and the brake control valve. Preferred embodiments of the device include an inlet port communicating with a brake valve and an outlet port communicating fluid pressure to a vehicle brake. A control assembly is provided intermediate the inlet and outlet ports and includes mechanisms for amplifying the hydraulic pressure effect in the direction from the outlet port to the return pressure system so that the brake return pressure exerted by the brake return springs can be substantially less than the hydraulic system return pressure.

Abstract: The invention is concerned with a device that cuts off pressure in the final positions of the steering movement in an auxiliary-power steering device. In steering devices that have movable working pistons in the steering gear housing, this cut-off device is installed in a through drilled hole in the working piston. A by-pass valve that is activated by a push rod touching the wall of the housing is provided for every direction of steering. To avoid time-consuming adjustment work on the by-pass valves the walls contain bushings located opposite the push rods that are automatically pushed into the final positions corresponding to the wheel steering angle after the auxiliary-power steering device is installed in the vehicle. That happens as a result of rotating, first without auxiliary power, against the wheel limit stops, with the front axle jacked up, after the preliminary installation of the bushings in their drilled holes.

Abstract: A hydraulic device includes a piston slidable within a cylinder. Fluid under pressure is admitted to one end of the cylinder through an inlet which contains a restrictor. The piston is formed with an orifice and is biased by a first spring towards the one end of the cylinder. A thrust rod is engageable by the piston to transmit the movement of the piston to an external mechanism. When the piston is moved by rising fluid pressure the orifice is closed by the end of the thrust rod so that a higher value of fluid pressure is required to effect the initial movement of the piston than is required to allow the return movement of the piston.

Abstract: A compactor includes a longitudinally extending ground supported frame having an open end and a closed end. A cylinder and piston assembly is positioned within the frame and extends longitudinally therealong and a ram is secured to the piston for transferring waste through the open end. The cylinder has fluid ports at opposite ends thereof. An hydraulic fluid supply assembly introduces pressurized fluid to said ports for causing selective movement of the piston relative to the cylinder. An hydraulic spool valve is carried by the piston for permitting fluid to flow between the ports and for thereby preventing displacement of the piston when the dwell assembly engages one of the ends.

Abstract: A stroke limiter for a hydraulic cylinder comprises two sleeve portions each having a channel located therein that are frictionally mounted to the piston rod adjacent to the piston. An elongated contactor is slidably received in each of the channels. The contactor is longer than the sleeve portion and extends past the bottom of the sleeve. The top of the sleeve is provided with a cutout portion which is adjacent to the contactor and provides a hydraulic fluid flow path from the piston mounted poppet valves. When the contactor contacts the end cap of the cylinder, the contactor slides upwardly in the sleeve and contacts the poppet valves in the cylinder unseating the valves and creating a hydraulic fluid flow path across the piston.

Abstract: This invention pertains to a pneumatic mode under which the structure of a hydraulic system is driven, particularly denoting the pneumatic mode under which a mini air compressor is being used as a means to elevate a hydraulic jack.This invention makes use of a working lever and a working body attached to the hydraulic mechanism which is compactly closed inside a body to drive the hydraulic lever of the hydraulic mechanism which is compactly closed at the other end of the body to conduct a continuous backward/forward movement which will press against and elevate the hydraulic jack. Such a movement is similar to a continuous backward/forward movement conducted by a piston in a cylinder body. However, the entire structure and effected of this invention is found much better because of its easy fabrication and its function of elevating the hydraulic jack by means of a pneumatic mode, which saves both time and strength and thus meet the requirement of a simple and automatic operation.

Abstract: A jack with drain valve including a housing having a first cylinder and a first piston; the first piston defining a second cylinder into which a second piston is reciprocally mounted. A drainage tube is defined by the first piston, the drainage tube extending between the second cylinder and the bottom, workpiece engaging surface of the piston. When both first and second piston engage a workpiece, hydraulic fluid may be forced through an inlet port into the first cylinder, placing pressure against both first and second pistons in their engagement with the workpiece; the drainage tube being obstructed by the second piston. Once the workpiece is moved or the jack retracted, pressure on the hydraulic fluid in the first cylinder, which may be applied by upward pressure on the first piston, forces the second piston downwardly beyond the inlet port of the drainage tube. In this manner the cylinders may be readily drained for reuse of the jack.

Abstract: An apparatus for readjusting first and second adjustable pressure relief poppet valves to vent the fluid pressure moving a piston when the piston is at the ends of a second work stroke which is of a length less than a first work stroke for which the poppet valves are adjusted. Each of the poppet valves is carried by the piston and includes a valve seat and a valve member movable relative to the valve seat. The piston is disposed in a fluid chamber defined by a housing. The piston divides the fluid chamber into first and second chamber portions. One of the chamber portions is pressurized and the other is vented to move the piston in a work stroke. The apparatus includes a member supported by the housing for moving the seat of the second poppet valve outwardly relative to the piston in response to the member moving relative to the housing and engaging the seat of the first poppet valve to move the seat of the first poppet valve inwardly relative to the piston.

Abstract: A fluid pressure control device is described effective to actuate an external device when the differential-pressure between a high-pressure fluid source and a lower pressure fluid source rises to a predetermined magnitude. The control device comprises a housing having a partition wall therein dividing its interior into two compartments communicating with each other through an opening in the partition wall. A differential-pressure sensing member is disposed in one of the compartments and is movable therein in response to the sensed differential-pressure. A stem is fixed to the differential-pressure sensing member so as to be moved therewith and carries a valve member at one end for moving it with respect to the valve opening to control the flow of the fluid therethrough and thereby to actuate the external device.

Abstract: This invention relates to a valve suitable for location within a passage or bore of a piston or piston rod of a hydraulic ram assembly. The valve includes a valve body mountable in the bore or passage and a chamber provided in the valve body having a pair of fluid access ports preferably having a relatively narrow outer passage and an enlarged inner space which may function as a valve seat. There is also provided a pair of valve members wherein each valve member may co-operate with a respective valve seat to close or open same to fluid flow through the valve chamber.

Abstract: A hydraulic cylinder is disclosed having a hollow cylinder with a closed first end and an open second end. A rod is positioned in the interior of the hollow cylinder and the rod is securely connected to the first end of the cylinder. The rod is positioned in substantially the center of the hollow cylinder and is substantially parallel to the longitudinal axis of the cylinder. The end of the rod that is spaced apart from the first end of the cylinder has an area of enlarged cross-section. A movable piston having a first end and a second end positioned with the first end of the piston being in the interior of the hollow cylinder. The second end of the piston extends from the open end of the hollow cylinder. The first end of the piston defines a slot for receiving the end of the rod having an enlarged cross-section. The slot is disposed to receive the end of the rod having the enlarged cross-section when the slot and the end of the rod are properly aligned.

Abstract: A fluid-operated ram, for example comprising a cylinder 10 and piston 12, is provided for actuating a device such as a chuck having jaws 15. When the jaws are moved by the ram to grip a workpiece this constitutes a limiting position which impedes the flow of fluid thus causing a build-up of fluid pressure within the ram. This build-up can be detected to give an indication as to when a workpiece has been securely and safely gripped. To ensure that a false indication is not given if the ram reaches an end of its working stroke before the workpiece is securely gripped, means (22) are provided to relieve pressure within the ram when the ram reaches an end of its working stroke.

Abstract: A hydraulic trim-tilt system for an outboard motor (10) utilizes a first pilot operated relief valve (48) in one trim piston (21) to limit the stroke of the trim pistons (21, 22) under load. After the trim pistons have reached the top of their stroke, under reduced load, the first pilot operated relief valve (48) is blocked and a second pilot operated relief valve (58) operates to allow a higher pressure to be supplied to the trim-tilt unit (16) to lift the outboard propulsion unit (15) in a higher shallow water drive range.

Abstract: A driving apparatus for producing a to-and-fro movement and having four plunger cylinders and four external non-return valves. Such driving apparatus is distinguished by a particularly simple construction.

Abstract: A power assist steering gear for use in vehicles having a housing that defines a chamber. A piston dividing the chamber into first and second chamber portions. The piston is movable through a work stroke in opposite directions in the chamber. A steering valve directs fluid pressure into the first chamber portion and vents the second chamber portion to effect piston movement in a first direction and directs fluid pressure into the second chamber portion and vents the first chamber portion to effect piston movement in a second direction. An input shaft moves to effect actuation of the steering valve. A relief valve for communicates the first and second chamber portions when the piston is near the end of its work stroke.

Abstract: An apparatus for the exact position feedback of a double-acting power piston in a hydraulic power cylinder subjected to extreme environmental conditions, especially high temperatures, comprising a double-acting detecting (measuring), or follower cylinder, having a volume corresponding to that of said power cylinder and including a detecting piston the position of which is sensed by an electrical detector, wherein a pair of working spaces of power and detecting cylinders are in fluid communication with each other via a connecting pipe, while the respective other working spaces are adapted to be connected to a (pressursized) fluid pump or a reservoir through a control valve.