Abstract: A hydraulic cylinder includes a cylinder assembly having a cylinder, defining an inner hydraulic chamber and being for reciprocating receipt of a piston and piston rod therein; a piston rod extending from the inner hydraulic chamber exteriorly of the cylinder; and a piston head assembly connected with the piston rod and disposed for reciprocation within the cylinder assembly. The piston head assembly includes a piston head and a valve assembly including a passageway defined in the piston head and a valve member having an outer surface and being sized and configured for reciprocation in the passageway between extended and retracted positions therein, the valve member defining at least one flat defined along the outer surface and at least one transition surface between the outer surface and the flat, the transition surface forming an angle with the flat of between about 40 and 50 degrees.

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 hydraulic cylinder includes a cylinder assembly having a cylinder, defining an inner hydraulic chamber and being for reciprocating receipt of a piston and piston rod therein; a piston rod extending from the inner hydraulic chamber exteriorly of the cylinder; and a piston head assembly connected with the piston rod and disposed for reciprocation within the cylinder assembly. The piston head assembly includes a piston head and a valve assembly including a passageway defined in the piston head and a valve member having an outer surface and being sized and configured for reciprocation in the passageway between extended and retracted positions therein, the valve member defining at least one flat defined along the outer surface and at least one transition surface between the outer surface and the flat, the transition surface forming an angle with the flat of less than 90 degrees.

Abstract: An improved uniflow engine has a plurality of vertically extending cylinders distributed in-line along a horizontally extending common crankshaft connected to pistons reciprocating in the cylinders. A working fluid vapor is supplied to those cylinders in which the respective pistons are in their working strokes to initiate rotation of the crankshaft in a predetermined direction regardless of where the crankshaft has stopped last. Once rotation is initiated and a predetermined mode change speed attained in a “start-up mode” engine operation, vapor inlet valves are controlled by an inlet valve control mechanism to change engine operation over to a “running mode”. In the start-up mode, incoming vapor is admitted over a substantial portion of the piston working stroke, whereas in the “running mode” vapor inflow is terminated relatively early in the working stroke so that a vapor change does work in expanding against the piston.

Abstract: A double-acting reciprocating motor with a uni-directional fluid flow path comprises a piston disposed within a cylinder. Within the cylinder, the piston defines a first chamber between the piston and a cylinder base and a second chamber between the piston and a cylinder head. Fluid is introduced into the first chamber of the motor through an inlet port associated with the cylinder base. A pass-through valve controls the flow of fluid from the first chamber to the second chamber. An outlet valve regulates the draining of fluid from the second chamber through an outlet port associated with the cylinder head. Fluid pressure within the first chamber urges the piston towards the cylinder head when the pass-through valve is closed and the outlet valve is open. The piston surface facing the second chamber is larger than the piston surface facing the first chamber, so the piston moves towards the cylinder base when the pass-through valve is open and the outlet valve is closed.

Abstract: A double-acting reciprocating motor with uni-directional fluid flow path comprises a piston disposed within a cylinder. A first chamber is defined by the cylinder space between the piston and a cylinder base. A second chamber is defined by the cylinder space between the piston and a cylinder head. Fluid is introduced into the motor through an inlet port and into the first chamber. A pass-through valve controls the flow of fluid from the first chamber to the second chamber. An outlet valve regulates the draining of fluid from the second chamber through an outlet port. The outlet port and the inlet port are associated with opposite ends of the motor. Differential fluid pressure urges the piston towards the cylinder head when the pass-through valve is closed and the outlet valve is open. The piston surface facing the second chamber is larger than the piston surface facing the first chamber, so the piston moves towards the cylinder base when the pass-through valve is open and the outlet valve is closed.

Abstract: A percussive hammer for delivering impacts driven by oil which is quickly applied under pressure derived from a system supply and from a source of compressed gas.

Abstract: A reciprocating fluid driven motor apparatus is provided for operating within a pipeline system carrying fluid under pressure to harness some of the energy stored in the presssurized fluid and convert it into mechanical motion for performing other desired tasks. The apparatus includes a barrel having an inlet in fluid communication with an upstream portion of the pipeline and an outlet in fluid communication with a downstream portion of the pipeline, and a differential pressure regulator in a by-pass portion of the pipeline connecting the upstream and downstream portions to create a greater pressure in the upstream portion than the downstream portion. A piston slides reciprocally within the barrel in a fluid tight manner. The piston has an interior cavity for allowing fluid movement therethrough, and a cyclically operable closure member for opening and closing the fluid movement through the piston.

Abstract: A shuttle valve mounted between a pneumatic piston and a ring plate in a reciprocating pneumatic motor and moved to control the passage between a shuttle compression chamber and a radial air inlet hole in the pneumatic piston, the shuttle valve having a press rod supported on a compression spring and forced out of the front end of the body of the shuttle valve for pressing against the cylinder cover of the reciprocating pneumatic motor, enabling the shuttle valve to shut off automatically at an early stage so as to extend the piston stroke when the pneumatic piston bears the load, or to shorten the piston stroke when the pneumatic piston bears no load.

Abstract: A uniflow engine has a plurality of cylinders disposed symmetrically around a common crankshaft connected to pistons reciprocating in the cylinders. In response to the availability of a working fluid vapor at a predetermined condition, such as a high pressure or temperature, incoming vapor is supplied to those cylinders in which the respective pistons are in their working strokes to thereby initiate rotation of the crankshaft in which the crankshaft had stopped last. Once rotation is initiated and a predetermined mode change speed attained in a "start-up model" by engine operation from start, vapor inlet valves are controlled to change engine operation over to a "running mode". In the "start-up mode" incoming vapor is admitted over a substantial portion of the piston working stroke, whereas in the "running mode" vapor inflow is terminated relatively early in the working stroke so that a vapor change does work in expending against the piston.

Abstract: The invention relates to a reciprocating piston motor. The motor comprises at least one cylinder which is closed on at least one end, a piston which is slidable in the cylinder and forms a pressure chamber with the closed end of the cylinder, a power transmission element such as a piston rod coupled to the piston and extending outside the cylinder.

Abstract: A direct action fluid motor and injection pump is disclosed which injects small quantities of a second fluid into a primary fluid stream. A housing has an inlet and an outlet connected to a primary fluid conduit. The housing contains a stepped piston which reciprocates in response to the fluid pressure applied alternately to the closed small and large face of the piston. A valve set alternately closes one and opens the other of the faces. A valve positioner carried with the piston is held in alternate stable positions by cooperating springs on the valve positioner and a post in the piston. Stop members are located above and below the piston travel, each associated with an actuating spring. The valve positioner is preshifted at the end of the stroke, using the full force of the piston, by stop members to move the valve positioner and valve set to an intermediate unstable position.

Abstract: The device (D) for controlling the reciprocating displacements of a differential piston (1) includes at least one valve associated with each of the parts of different cross-sections of the piston (1), and a rocker mechanism (B) urged by a spring in a direction transverse to the direction of displacement of the piston (1). The rocker mechanism (B) is designed to control the valves in closure and/or opening at each end of stroke in order to reverse the movement of the piston (1); a push rod (55) is mounted so that it slides relative to the piston (1), whilst being able to be driven by this piston, the push rod being capable of coming to bear, at each end of stroke, against a limit stop (s, 14a) connected to the enclosure, in order to give rise to the rocking of the mechanism (B).

Abstract: An impact device for breaking up and separating hard material comprises an actuating system for providing a faster cycle rate as well as an increased impact force. More specifically, the device includes a pair of pistons movably arranged in a cylinder to cooperate in compressing the gaseous component prior to initiating the blow. A closed tube is provided to fluidly interconnect opposite chambers adjacent the two pistons to coordinate the different movements of the pistons to effect the desired compression. The impact device is particularly well suited for use in an impact bucket.

Abstract: The invention relates to a reciprocating hydraulic motor having a differential piston interposed between an inlet pipe for fluid at a pressure P1 and an exhaust pipe for fluid at a pressure P2 which is less than the pressure P1 The moving assembly constituted by the different-section pistons that slide in a stepped cylinder includes a flap having two positions and controlling three ports, the flap being mounted to pivot about an axis. In each of its positions, the flap bears against two wall portions disposed on opposite sides of the flap and at different distances from the pivot axis so that the effect of the pressures P1 and P2 on the faces of the flap is to establish a positive closure torque.

Abstract: A magnetically actuated fluid motor has a shiftable member having valve members for alternately closing one and opening the other of large and smaller faces of a stepped piston reciprocating in a housing. The shiftable member carries a magnet and is shiftable to collocate the magnet with one of spaced apart magnet attractors. A magnetic holding force between the magnet and attractors exceeds a simultaneous resilient counterforce supplied by spring members operating on the shiftable member. When the magnetic holding force is weakened by application of a separating force to separate the magnet from an attractor, stored energy in the compressed springs is released to shift the shiftable member. Separating force is applied through stops which arrest the shiftable member while the piston continues to move, without immediately opening the closed face of the stepped piston.

Abstract: An air operated reciprocating piston pump having a differential area piston is provided with an annular shaped airfoil device having a chevron cross-section and which is located beneath the bottom air intake plate to utilize increasing air velocity at the initiation of bottom changeover in order to assure more reliable changeover.

Abstract: The present invention relates to a valve assembly (10) which is mounted on a part (piston unit 40) of an air motor (10) arranged for reciprocating movement in a housing (cylinder 12). The valve assembly includes a first valve unit (50), which is mounted on one side of the part (40), and a second valve unit (70), which is mounted on the other side of the part (40). The second valve unit is connected to the first valve unit (50) by means of the part (40) for common movement with the first valve unit relative to the part (40) when the valve assembly is switched as the part (40) reaches one of its two end turning-positions.

Abstract: An actuator is driven in a first direction by equal working fluid pressures acting on different piston areas acting in opposite directions, and is driven in a second direction by applying equal pressures on both sides of one of the piston areas. Working fluid from an inlet port, acting in a working fluid chamber, pushes up a valve plate, closes ventilation holes and opens working fluid discharge holes, thereby permitting the working fluid to push the piston upward. Working fluid contained in the working fluid chamber is exhausted from working fluid discharge holes to the outside of the system through a working fluid discharge pipe. When the upward movement of piston reaches its limit, a valve plate is pushed by a spring, thereby causing simultaneous closing of the working fluid discharge holes and the opening of the ventilation holes. As a result of the opened ventilation holes, working fluid pressures in a lower working fluid chamber and an upper working fluid chamber become equal.

Abstract: A reciprocating primary fluid driven motor has a stepped piston in a housing having a center hanging actuator rod which extends into the piston to periodically cooperate with an axially shiftable connector member in the piston which operates valves which establish the reciprocating stroke of the piston by opening and closing valve members on the larger and smaller faces of the stepped piston. A block member with compression spring drivers pivotally mounted inside the piston slides on the actuator rod during movement of the piston. The drivers are compressed in response to spaced stops on the actuator rod during continued movement of the piston until a sudden over-center movement of the block member shifts the connector to operate the valve members to cause reciprocation of the piston. Quiet operation during shifting is provided by shock absorbers. No sliding seal with the actuator rod is necessary. Provision for bleeding air from the housing chamber facilitates startup.

Abstract: The objective of the present invention is to provide a reciprocation switching device for a pump which will solve problems of conventional devices such as that, because coil springs are used for activating by their snap action valve operators or switching operators serving to control the pressure of pump working fluid in relation to reciprocating action of the pump, such devices require the numerous number of parts including spring fitting shafts, the structure to attach such fitting shafts, parts for spring holders, etc.; and that the assembling of those parts is troublesome. A device according to the present invention uses one or two wire springs made into a C-like shape as the springs for the aforementioned purpose and calls for fitting said springs directly between the spring fitting section(s) and the valve operator or the switching operator.

Abstract: An impact hammer according to this invention has a frame to house its actuating mechanism and to support a working impact tool which is to receive a sharp impact blow from the impact hammer and deliver it to a structure or formation that is to be pierced or fragmented. The impact tool projects from the frame and is axially reciprocable in the frame. A hammer head is reciprocably mounted in the frame with a close sliding fit. It has an impact face that faces toward the impact tool to strike the tool when the impact is intended to occur. At positions beyond this intended range, the hammer head is braked so it does not impact the frame. The blow to the tool is a high-energy, sharp blow, and is not intended to contribute a follow-on application of force after the initial impact. The hammer head has a shank, a loading shoulder and a poppet port.

Abstract: A proportioning pump for liquid additive metering having a housing with a diaphragm piston therein and inlet and outlet primary fluid lines to said housing for moving said diaphragm piston up and down. Additive pistons for pumping an additive liquid into said primary fluid with said additive pistons being moved by said diaphragm piston.

Abstract: The objective of the present invention is to provide a reciprocation switching device for a pump which will solve problems of conventional devices such as that, because coil springs are used for activating by their snap action valve operators or switching operators serving to control the pressure of pump working fluid in relation to reciprocating action of the pump, such devices require the numerous number of parts including spring fitting shafts, the structure to attach such fitting shafts, parts for spring holders, etc.; and that the assembling of those parts is troublesome. A device according to the present invention uses one or two wire springs made into a C-like shape as the springs for the aforementioned purpose and calls for fitting said springs directly between the spring fitting sections(s) and the valve operator or the switching operator.

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

Abstract: A uniflow engine has a plurality of cylinders disposed symmetrically around a common crankshaft connected to pistons reciprocating in the cylinders. In response to the availability of a working fluid vapor at a predetermined condition, such as a high pressure or temperature, incoming vapor is supplied to those cylinders in which the respective pistons are in their working strokes to thereby initiate rotation of the crankshaft in a predetermined direction regardless of the position in which the crankshaft has stopped last. Once rotation is initiated and a predetermined mode change speed attained in a "start-up mode" by engine operation from start, vapor inlet valves are controlled to change engine operation over to a "running mode". In the "start-up mode" incoming vapor is admitted over a substantial portion of the piston working stroke, whereas in the "running mode" vapor inflow is terminated relatively early in the working stroke so that a vapor change does work in expanding against the piston.

Abstract: This invention relates to an air motor having a snap-acting overcentering spring mechanism for snapping the valving of the air motor between first and second positions as the piston completes each stroke in the cylinder to ensure reliable stall-free operation of the motor.

Abstract: Disclosed is a device for converting pressure fluid input of one fluid to pressure fluid output of a second fluid without contaminating either fluid. The transformation is accomplished by a unique H section piston which cooperates the internally protruding endcaps enclosed in a double ended cylinder; the piston having a central control valve which reverses the piston on control pin end of stroke contact. Positive reverse action is obtained by means of endcap plungers which operate in response to piston position and pressure of the one fluid. The device is double acting and is enclosed totally within a single cylindrical module which is compact and inexpensive to manufacture.

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: The invention relates to a device for injecting a metered product into a main circulation of liquid, comprising a metering piston (28) coupled to a stepped piston (11) whose motion results from the pressure of the main fluid in a known manner. The piston (28) interacts with a metering cylinder (10) which is in permanent communication with the lower part of the liquid outlet chamber (8). The mixture of the products is thus confined to the outlet of the device, while no leakproof sliding of a component on contact with either of the liquid and product is necessary, and this eliminates the risks of abrasion of the seals due to deposits on the sliding component. In addition, since the inlet chamber (6) for the main liquid is annular, it permits a filter (33) to be easily installed.

Abstract: A percussion tool utilizing a reciprocatory piston movement for applying an impact force on to a working surface including a casing (1) having disposed axially therein a hammer member (12), an anvil (5) impacted by the hammer member and a chisel point (4) supported by the anvil. A spool valve (18) is located within the interior of the hammer member for reciprocatory movement in unison with the hammer member, the control the flow of a pressurized working fluid supplied to the hammer member, to thereby cyclically move the hammer member in reciprocatory movement.

Abstract: A novel hydraulic tool used to cut cables, rods, bars and the like or crimp various items such as cable connectors and which is operated manually and with ease by a single man. The improved cable cutting hydraulic tool comprises dual manually held handles which centrally receive and exhaust the operating pressurized hyraulic fluid, a safety trigger assembly which prevents the inadvertent closing of the cutting or crimping jaws, and an operating trigger assembly, a control valve which directs and redirects the flow of hydraulic fluid under pressure, and a piston cylinder assembly which relatively reciprocates to displace operating rods which in turn causes the cutting jaws to close and open by rotation about a pivot pin. This cable cutting and crimping tool is light weight and compact in comparison with other contemporary designs and is much easier to handle and control during use.

Abstract: A novel hydraulic tool used to cut cables, rods, bars and the like or crimp various items such as cable connectors and which is operated manually and with ease by a single man. The improved cable cutting hydraulic tool comprises dual manually held handles which centrally receive and exhaust the operating pressurized hydraulic fluid, a safety trigger assembly which prevents the inadvertent closing of the cutting or crimping jaws, and an operating trigger assembly, a control valve which directs and redirects the flow of hydraulic fluid under pressure, and a piston cylinder assembly which relatively reciprocates to displace operating rods which in turn causes the cutting jaws to close and open by rotation about a pivot pin.

Abstract: A vibrationless percussion tool is disclosed characterized by use of a piston mounted for reciprocal movement against a constant pressure force within a casing to cyclically impact an anvil disposed adjacent the distal end of the casing. A spool valve is disposed within the interior of the piston and is adapted to travel in unison with the reciprocating piston except during mechanical actuation initiated adjacent the extreme downstroke and upstroke position of the piston within the casing. The constant pressure force is continuously applied to one side of the piston and by mechanical actuation of the spool valve, the volume disposed on the opposite side of the piston is alternatively vented and pressurized to cause reciprocation of the piston against the constant pressure source.

Abstract: Disclosed herein is a combined fuel and oil pump comprising a reciprocally movable member for pumping fuel in response to member reciprocation, a reciprocally movable element for pumping oil in response to element reciprocation, and a fluid pressure actuated motor connected to the member and to the element and responsive to a source of alternating relatively high and low pressures for effecting reciprocation of the member and the element at a frequency less than the frequency of the alternation of the relatively high and low pressures.

Abstract: A vacuum actuator, suitable for use in an automatic belt tensioning system, oscillates automatically when connected to a source of constant vacuum.

Abstract: A hydraulically driven reciprocating motor (10) includes a hydraulic cylinder (12) and a piston (60) mounted for reciprocation within the cylinder. The piston has passageways (74) formed therethrough which are normally sealed by a floating valve (90). Rods (76) are carried by the piston (60) and normally project from one end thereof. When the piston (60) reaches the limit of its travel in one direction the rods (76) disengage the floating valve (90), thereby opening the passageways (74) through the piston (60) to permit movement of the piston (60) in the opposite direction. When the piston (60) reaches the limit of its travel in the opposite direction, the floating valve (90) again seals the passageways (74) through the piston (60) to complete the operating cycle of the motor (10).

Abstract: Hydraulic engine with piston moving inside a chamber, the working and reversing controls being inside the piston.Said engine comprises a piston (6) which is provided with an annular chamber (15) into which the fluid is admitted through two conduits (13 and 14). From said chamber (15), the fluid passes through the conduit (17), the groove (19) and the conduit (21) and then through the reversing valve (22a) and from there via the conduits (28,29) into the lower chamber (2a). The fluid contained into the upper chamber (2b) is removed through the conduits (30 and 31) traverses the valve (22a) and arrives through the conduit (32) into the groove (33). It is then removed through the conduit (34) and the chamber (35) surrounding the column (4) towards two exhaust channels (37 and 36).This engine finds an application in driving the slide valve of a self-cleaning filter.

Abstract: A liquid-operated reciprocating prime mover assembly includes upper and lower reservoirs formed of interlocking cylinders enabling relative expansion and contraction of the interior volumes thereof, and a shuttle valve disposed intermediately and connectingly between the upper and lower reservoirs for receiving a stream of operating liquid and directing the same alternatingly between the reservoirs. As the liquid is directed to each reservoir that reservoir is caused to expand, carrying the shuttle valve in a first direction along a rectilinear path, while when fed to the other reservoir the liquid causes the valve to be correspondingly carried in the opposite direction along the path. A body washing apparatus incorporating the prime mover assembly further includes an operatively rotatable brush assembly carried along the rectilinear path and supporting a brush rotatable as the shuttle valve traverses the path for cleansing contact with a user's body.

Abstract: An air-hydraulic pump wherein an air-motor drives the pump. The air-motor includes a reciprocal piston which is driven in one direction by fluid under pressure and is returned by a spring. A control valve is utilized to control the action of fluid under pressure on the piston with the control valve having an open position which is maintained by trapped fluid pressure within a piston chamber in which the control valve is positioned. The control valve is closed by physical contact thereof with an end wall of the cylinder movably mounting the piston at the end of the return stroke and a resilient member is positioned adjacent the cylinder end wall to maintain the control valve in closed position for a portion of the piston stroke as it moves away from the cylinder end wall in the pumping stroke to avoid a possible stall condition for the motor.

Abstract: A cylindrical shell with a double acting piston, having a high pressure area and a low pressure area on each side thereof, is provided with a valve for alternately injecting high pressure gas to each small area to provide an initial piston drive, and valving for injecting gas under the pressure, opposite from the first high pressure end to the opposite larger area providing a secondary piston drive using expansion of the high pressure expanded gas from the opposite end of the piston. In reversing the piston, the opposite end becomes the drive end in the same manner. In one form, a two position slide valve, initially actuated by piston movement and completed by gas pressure movement, provides a transfer means for gas streams internally of the motor and for exhaust of the secondary expanded gas. The valve is arranged for an initial mechanical movement from one position toward the other position by contact with the end wall of the low pressure cylinder and then completely moved to other position by gas pressure.

Abstract: Disclosed is a vacuum pump device that is adapted to create a vacuum source from a source of high pressure air. The device comprises a piston actuated in one direction by compressed air and in the opposite direction by a power return spring. The compressed air moves the piston to load the spring and the spring moves the piston to create a vacuum. A special dumping valve is also provided which is actuated toward the end of the return stroke of the piston to cause a sudden increase in the pressure differential across the piston to prevent stalling of the piston when loading is such that the piston moves very slowly, thereby assuring that the vacuum pump will cycle as often as is necessary to maintain the desired vacuum.

Abstract: A windmill in which a propeller is directly fixed to the shaft of a rotary hydraulic pump mounted on a cylinder casing rotatably mounted about a vertical axis to the top of a tower. A piston in the cylinder is recicprocated by the hydraulic fluid expelled by the pump to power a reciprocal pump at the base of the tower to which the piston is attached by a lift rod. The piston is fitted with a valve which permits the piston and attached lift rod to freely move on the downstroke through the fluid in the cylinder, with the valve closed during the upstroke of the piston to permit the pressurized fluid below the piston to raise the piston and lift rod.

Abstract: A new control system is provided for a reciprocating fluid stroke motor of the type which is pressured at its rod end, reciprocation being achieved by intermittent exposure of its full blind-end face to the pressure fluid to overcome the pressure applied to its smaller rod-end face. The control means includes a valve for a passage through the piston, with adjustably-positioned trip-stops for shifting the valve between open and closed positions. The valve is biased to snap fully open when the piston movement toward its opening-stop opens it slightly and remain open until striking the closing-stop. Monostable or bistable trip-switch types of biasing means may be used, and unless one holding the valve closed with no fluid pressure is chosen, resumption of pressure supply after discontinuance will cause an initial retraction of the piston to its starting position, allowing time for the controlled apparatus to attain acceptable speed.

Abstract: The invention relates to apparatus for and the method of reversing the operation of a power piston in a power cylinder automatically to pump oil, corrosive or wax bearing fluids. The flow of high pressure fluid driving the piston in one direction may be reversed to drive the piston in the opposite direction at the end of the respective strokes by establishing a collapsible chamber for the high pressure fluid within the piston. This chamber is at least partially collapsed toward the end of each stroke by the stem of an auxiliary reversing piston striking a stop slightly before the end of the stroke to partially collapse said chamber and establish a further chamber on the opposite side of the reversing piston.

Abstract: A reciprocating cylinder assembly for self-propelled sprinkler systems and the like comprising a cylinder tube having hollow plugs at each end having slidably engaged therein, a piston rod, said piston rod being surrounded by a repositionable valve slide and a piston. The piston rod projects through the hollow plugs at each end of the cylinder tube and have fluid inlet and outlet means at each end of the piston rod. When pressurized fluid is delivered to one end of the piston rod, the piston rod moves relative to the cylinder in a direction opposite to the direction of the entering fluid, and fluid is forced from the outlet at the opposite end of the piston rod until the valve slide engages the end plug of the cylinder tube whereupon pressure causes valve detents to slidably change positions thereby causing a reversal of fluid flow and the change of direction in the movement of the piston rod.

Abstract: This invention relates to a hydraulic motor device comprising a cylinder and a piston reciprocating therein said piston being moved in one direction by means of a spring and in the other direction by means of fluid under pressure supplied against one side of the piston, said cylinder including an inlet for fluid at one end and an outlet for fluid at the other end, and said piston including an overflow aperture from one working side to the other, which aperture is controlled by a stop valve that is either completely open or completely closed depending upon its impact against two spaced apart points on the cylinder end walls.

Abstract: A device for injecting adjuvant into a liquid employing a stepped piston in a stepped cylinder with a valve in the piston triggered to open and close at opposite ends of the piston travel to cause a reversal of piston movement while a further piston integral with the first mentioned piston operates to pump metered quantities of adjuvant into the stepped cylinder.

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