Abstract: A thermodynamic system for powering a reciprocating device includes a refrigerant passing in a closed loop between a refrigerant compressor, a condenser, an expansion valve, and an evaporator. The system includes a heat source for heating the refrigerant, and an engine for receiving the heated refrigerant. The engine includes a housing, a shaft axially movable within the housing, a piston attached to the shaft, a shifter for reversing piston direction, and porting for passing the refrigerant into and out of the engine housing.

Abstract: A two-step hydraulic valve is described. In an implementation, a two-step hydraulic valve with retrograde spool action has a pilot spool that controls hydraulic force applied to a main spool to switch a rod of a hydraulic actuator back-and-forth between extension and retraction. The main spool is hydraulically driven in retrograde motion to the pilot spool, providing improved reliability and switching action for the valve. The pilot spool also has an overtravel feature that can be used to hyperextend the rod for various purposes. In an example system, the two-step hydraulic valve controls a hydraulic actuator connected to drive a submersible reciprocating pump, such as a diaphragm pump.

Abstract: An air logic controller for increasing the efficiency of an air operated double diaphragm pump. The air logic controller may increase the efficiency of the pump by controlling the supply of compressed fluid to the pump. In one embodiment, the air logic controller may control the supply of compressed fluid to the pump by replacing the continuous, large volume supply of compressed fluid supplied to conventional air operated pumps during a single pumping stroke with a varied supply of compressed fluid. The varied supply of compressed fluid may comprise a supply of compressed fluid that alternates between a large volume supply and a small volume supply of compressed fluid. The air logic controller may vary the supply of compressed fluid to the pump based at least partially on the position of a main air valve spool and the setting on an adjustable pneumatic time delay relay.

Abstract: A valve arrangement for placing a supply of motive fluid in alternating communication with first and second motive fluid chambers. The valve arrangement includes a power valve including a supply chamber, a pilot chamber, and a shiftable member separating the supply chamber from the pilot chamber. The valve arrangement also includes a pilot valve actuable between an on condition in which the pilot valve generates a pilot signal that shifts the power valve, and an off condition in which the pilot valve does not generate the pilot signal. At least a portion of the pilot valve is exposed to motive fluid, and the portion of the pilot valve exposed to motive fluid includes surface areas giving rise to a net zero actuating force arising from pressure of the motive fluid. Because there is no biasing force on the pilot valve, the pilot valve is shifted between the on and off conditions without significant resistance.

Abstract: A reciprocating drive mechanism having a housing with upper and lower internal chambers with a spool slidably positioned inside the upper internal chamber. There is at least one fluid inlet and fluid exhaust communicating with the upper internal chamber and at least one slide valve positioned within the upper internal chamber and traveling with the spool. A piston positioned in the lower internal chamber divides the lower internal chamber into an upper and lower cylinder space. There is at least one fluid conduit communicating between the upper internal chamber and the upper cylinder space and at least one fluid conduit communicating between the upper internal chamber and the lower cylinder space. A valve stem is connected to the piston and includes a bore communicating with the upper internal chamber and an exhaust passage is positioned between the upper and lower internal chambers.

Abstract: A submersible pump includes a pump valve configured to switch the pump between first and second states in which a piston is respectively extended and retracted. The pump valve includes first and second components that reciprocate between corresponding first and second positions. The pump is in the first state when both components are in their corresponding first position. The pump is in the second state when both components are in their corresponding second position. Neither the valve nor the pump is hydraulically locked at any time during normal operation.

Abstract: Fluid pump assembly driven by a reciprocating piston, having an improved coupling between a driving shaft and a driven shaft and a fast-shifting switching mechanism for changing the direction of movement to the piston.

Abstract: A hydraulic drive system is provided to produce a smoothed or near sinusoidal output flow characteristic for reciprocating piston pumps. The device occupies a smaller footprint than conventional mechanical reciprocating pumps and allows a standard reciprocating pump to operate at its maximum rated pressure while retaining its maximum rated flow. Several embodiments are disclosed and the drive system may be coupled to standard duplex and triplex pumps. A solution to hydraulic hammer caused by rapid flow reversal in the hydraulic control valves used within the system is presented.

Abstract: A pneumatically operated hydraulic pump includes a cylinder housing accommodating a main piston to subdivide the housing interior in two working chambers. The main piston is connected to a hydraulic piston for joint reciprocation so that the hydraulic piston can carry out a suction stroke when the main piston moves to one end position and a pressure stroke when the main piston moves to the other end position. Arranged laterally to the cylinder housing is a control mechanism for regulating a flow of working fluid alternately to the working chambers. The control mechanism includes a plastic valve casing for accommodating a control piston having opposite end faces of different size to define different effective areas and thereby realize reciprocation of the control piston by the working fluid. A slide shoe is guided in the valve casing for conjoint movement with the control piston.

Abstract: A compact transportable compressed-air piston engine for paint-spraying devices, dosing pumps, grease guns or the like, makes it possible, without much effort, to carry out various length working strokes of a working piston. A compact engine is obtained by mounting the control in/on the cylinder head or in/on the cylinder bottom with axes extending transversely with respect to a main axis so that stroke changes can be achieved solely by the working piston contacting the valve piston rods of switch valves. In addition, return springs are not needed in the switch valves, which are required for reversing and are operated by the working piston.

Abstract: A pneumatic or hydraulic cylinder assembly (10) includes a cylinder (10), a piston (12) axially slidable within the cylinder (10), and structural elements are disposed within the cylinder (10) to issue a piston (12) position signal in response to the piston reaching a predetermined position.

Abstract: Provision is made for an air control valve to bypass the ice forming exhaust of a reciprocating pressure activation chamber in a reciprocating double diaphragm pump utilizing the supply pressure to close a check valve in line between the valve and the chamber which is then opened to exhaust by exhaust fluid flow from the chamber.

Abstract: A pneumatic assist valve receives constant air pressure from supply air to provide the pneumatic assist to shift the pilot, eliminating false signals acting on the trip rod and the design also assures the pilot has completely shifted before diaphragm reversal occurs.

Abstract: A pilot control relay valve to change the directional flow of fluid to a piston (such as, for example, the piston of a chemical injection pump for injecting chemicals at a slow or rapid rate over a long period of time), but also allow the recovery of exhaust fluids under significant back pressure. The pilot control relay valve comprises an elongated valve member shiftable within a valve body between a first and second position. The first position allows communication of control fluid to a first pressure receiving surface while allowing exhausting of fluid from a third or opposing pressure receiving surface, thereby to initiate movement of the valve member against the back pressure of the exhaust fluid from its first position to a position equalizing the pressure acting on a second pressure receiving surface with the pressure of the control fluid, thereby causing the valve member to move to its second position.

Abstract: A pneumatic valve, designed to control/pressurize a membrane pump, compresses a valve body (1) having gates (8-12) for compressed-air-flow/operation/pressurization of said pump. The valve body is closed by ends (2), between which a plunger (5) is to move between two end positions. The ends of the plunger and the ends of the valve body co-operate physically magnetically in order to generate just and only a retaining force, which constitutes a threshold for a certain minimum control pressure from a control-air-gate (13 or 14) and guarantees a rapid initial movement as well as a rapid transfer of the plunger to its opposite end position. Permanent magnets (15) are inserted in said plunger ends and/or in said valve body ends and designed to co-operate with projections and/or processes (17,18,20) in the opposite member in order to obtain a so-called air-cushion-damping.

Abstract: A double diaphragm pump operated by selectively switching pressurized air into either of two diaphragm chambers; the air actuator valve is a cup valve which is slidable over orifices in a valve plate, and actuable by air pistons; the air pistons are coupled via passageways to a pilot valve which is a second cup valve slidable over orifices in a valve plate, the cup valve being actuable by pins extending into the diaphragm chambers and into contact with diaphragm members at predetermined positions.

Abstract: An improved control mechanism for submerged reciprocating hydraulic pumps comprising, in combination with pump cylinders, pistons and valves, a two-stage flow reversing mechanism in which action of the pump pistons drives a valve pilot means between two rest positions; relocation of the pilot means in turn causes relocation of a spatially separated spool mechanism between two rest positions, thereby causing reversal of flow of fluid while the pump is driven by a one-way pressurizing pump. The two-stage reversing mechanism eliminates the possibility of having the reciprocating mechanism come to rest in a "dead center" or equilibrium position. The spool is mounted concentrically with the pump shaft, optimizing flow potential. The mechanism is relatively easy to assemble and repair.

Abstract: A fluid driven linear motor with a piston (4) in a cylinder (5) is supplied with driving fluid under the control of a sliding valve device (8) having a slide (9) being moved between its terminal positions and being retained therein by means of the driving fluid. A pilot rod (22) connected to the piston (4) controls the supply of driving fluid to the respective sides of the slide (9). The pilot rod (22) is slidingly received in a cavity (12) in the slide and has sections (23-25) of reduced diameter which act as valves in certain positions.

Abstract: A cylinder including a housing disposed between a head and a board, a body disposed in the housing and closely contacted with the head, a piston slidably disposed in the housing, a piston rod coupled to the piston, a valve including five rings being disposed in the head, a valve including five annular grooves being disposed in the body, an inlet being formed in the head for continuously supplying hydraulic oil into the cylinder, the piston can be urged to move in a reciprocating action without changing the supplying direction of the hydraulic oil.

Abstract: An apparatus for driving a piston by fluid pressure in which a piston (8) is reciprocated upward and downward by supplying and discharging pressure fluid to and from an actuation chamber (9) disposed in a cylinder (7) through a pilot valve (18) and a fluid pressure supply-discharge valve (13). Above a supply-discharge valve member (30) of the supply-discharge valve (13) there is provided a cylinder chamber (70a), into which a pilot valve casing (71) is inserted so as to hermetically slide up and down. The fluid pressure in the discharge actuation chamber (35) disposed above the supply-discharge valve member (30) allows the pilot valve casing (71) to ascend against a return spring (73).

Abstract: Hydraulic drive mechanism for a machine element with rapid feed movement and under-load feed movement, comprising a double-acting hydrocylinder power drive and a pressure switching valve responding to the pressure at least in a larger operating chamber of the hydrocylinder when the pressure in the operating chamber exceeds a threshold value higher than 1/4 of the operating pressure of the pressure supply source, but lower than half the operating pressure thereof, switches to under-load feed operation and, when the pressure in the drive pressure or operating chamber falls below the threshold value, switches back to rapid feed operation. The pilot valve for the main control valve is equipped with two windings effective in opposite directions.

Abstract: A piston-driven down hole pump and a method for using the same to lift fluid on both its upstroke and downstroke. The pump is powered by a waste water injection pump. A drive piston connected to a production piston and three-way valve power the down hole pump through the steady flow of the power fluid from the injection pump. The power fluid is exhausted into the well annulus and rises to the surface comingled with the fluid.

Abstract: Briefly, the present invention comprises a combined mechanical shifting mechanism and pneumatic pilot valve construction to contrl the cycling of a double diaphragm pump. The mechanical cycling or shifting mechanism is positioned between pressure chambers of the diaphragm pump in the pump housing and extends axially into one or the other pressure chamber. The shifting mechanism moves axially in response to engagement by one of the pump diaphragms. Upon engagement by a diaphragm, the mechanical shift opens fluid pressure passageways to a pneumatic pilot valve which controls fluid flow to the respective pressure chambers associated with the diaphragm pump. A positive pilot signal is thus supplied through the entire stroke or cycle of the diaphragm pump. The mechanical shifting mechanism is not connected directly to a diaphragm or to the connecting rod which connects the diaphragms.

Abstract: An air-operated expansible chamber motor comprising a cylinder having first and second end heads, a piston reciprocable in the cylinder, a spool valve for controlling the supply to and exhaust of air from opposite ends of the cylinder, a relay valve mounted in one of the end heads for controlling the spool valve, a pilot valve in each end head having a stem engageable by the piston for controlling the relay valve via pressurization and exhaust of a pilot line, and a bleed for feedback of pressure air to the pilot line.

Abstract: A piston slidably inserted into a cylinder is reciprocated by fluid pressure such as pneumatic pressure and hydraulic oil and a spring is used to ascend the piston. A spool-shaped pilot valve element is provided to allow a supply-discharge valve disc to take supply and discharge positions, thus fluid pressure being supplied to and discharged from the cylinder. When the supply-discharge disc is actuated to take the supply position from the discharge position, the actuated force (supply position and discharge position) becomes stronger while the supply-discharge valve disc is in operation. When the supply-discharge valve disc is actuated to take the discharge position from the supply position, the back pressure resistance applied to the supply-discharge valve disc become weaker while the supply-discharge valve disc is in operation.

Abstract: A pilot control valve comprising an elongated valve member shiftable within a valve body between a first and a second position. The first position allows communication of control fluid to a first pressure receiving surface to initiate movement of the valve member from its first position to a position equalizing the pressure acting on a second pressure receiving surface with the pressure of the control fluid, thereby causing the valve member to move to its second position. The valve member when in its second position allows communication with a third pressure receiving surface for initially moving the valve member from its second position while equalizing the pressure acting on the second pressure receiving surface to move the valve member to a position equalizing the pressure acting on the second pressure receiving surface with a pressure lower than the pressure of the control fluid for moving the valve member to its first position whereby the operation is repeated at infinitum.

Abstract: A liquid motor is driven by pressurized wet glycol, received from an absorber of a natural gas dehydrating system, and utilizes the energy of the pressurized wet glycol to provide the primary source of energy for operating a pump for pumping of dry glycol from a reboiler to the absorber. A gas driven motor regulates the stroking rate of the glycol driven motor. The liquid motor and pump each have a two stage double acting piston in cylinders with fluid intake and exhaust valving and passages to alternately fill and exhaust the motor cylinders while the opposing pump cylinders are simultaneously alternately filled and exhausted. A spool type valve rod, associated with the glycol driven motor, is operated by the gas driven motor to regulate the rate of reciprocation of the glycol driven motor and to provide a secondary source of energy therefor.

Abstract: A positive displacement reciprocating pump for conveying a liquid or gaseous fluid is disclosed and which comprises a fluid enclosure having a movable piston means mounted therein which sealably divides the enclosure into a pumping chamber on one side and an actuating chamber on the other side. The piston means may comprise either a slideable piston or a flexible diaphragm. An inlet valve and a separate outlet valve are each connected to the pumping chamber, and a control system is provided for intermittently supplying a pressurized working fluid to the actuating chamber so as to intermittently move the piston means in the discharge direction, with the piston means being moved in the opposite or suction direction by either the pressure of the fluid being conveyed, or a suitable spring.

Abstract: A pilot control relay valve having first and second elongated valve members coaxially and independently longitudinally shiftable within a valve body between a first position of the first or leading valve member thereby allowing communication of actuating fluid from a supply to a first pressure receiving surface of the second or following valve member to initiate movment of the second valve member from its first position to a second position thereby allowing communication of the actuating fluid to a first pressure receiving surface of a main piston to initiate movement of the first valve member to a second position of the first valve member thereby allowing communication of supply fluid to the second pressure receiving surface of the second valve member thereby initiating movement of the second valve member from its second to its first position thereby allowing communication of supply fluid to a second pressure receiving surface of the main piston to initiate movement of the first valve member to its first pos

Abstract: A diaphragm pump pumping arrangement includes two diaphragm pumps which are arranged and operate in tandem. Each of the diaphragm pumps includes a housing and a movable wall that includes a flexible diaphragm and subdivides the interior of the respective pump housing into a pumping chamber and an actuating chamber. An air distributing control arrangement interposed between and connected to the pump housings includes a spool valve movable in a bore of an aluminum casing of the control arrangement between two end positions in which it alternatingly achieves the admission of the compressed air into one, and discharge of the air from the other, actuating chamber.

Abstract: Submergible pumping apparatus for use in an oil or other well comprises, in a self-contained downhole unit, a double-acting reciprocating positive displacement pump for pumping well fluid, a reservoir containing power fluid for operating the double-acting pump, a rotary motor-driven positive displacement pump for supplying power fluid under pressure from the reservoir to operate the reciprocating pump, and a control valve for properly directing high pressure power fluid from the rotary pump to the reciprocating pump and from the reciprocating pump back to the reservoir so as to provide stroke reversal of the reciprocating pump.

Abstract: The present invention provides for an improved diaphragm pump having two material pumping chambers. The material pumping chambers are operated by two working fluid chambers which are separated from the material pumping chambers by two diaphragms. The diaphragms are interconnected to provide that the two material pumping chambers alternatively receive and discharge the material to be pumped. A control valve controls the stroke reversal of the improved diaphragm pump. The control valve is actuated by the pressurized working fluid which is being discharged from a pressurized fluid chamber. Further valving provides for a portion of the pressurized working fluid being discharged from a pressurized fluid chamber to be reused and introduced into the exhausted fluid chamber to initiate expansion of the exhausted fluid chamber. The pre-pressurization of the exhausted fluid chamber reduces the amount of source air required at the beginning of the stroke.

Abstract: A diaphragm pump pumping arrangement includes two diaphragm pumps which are arranged and operate in tandem. Each of the diaphragm pumps includes a housing and a movable wall that includes a flexible diaphragm and subdivides the interior of the respective pump housing into a pumping chamber and an actuating chamber. An air distributing control arrangement interposed between and connected to the pump housings includes a spool valve movable in a bore of an aluminum casing of the control arrangement between two end positions in which it alternatingly achieves the admission of the compressed air into one, and discharge of the air from the other, actuating chamber.

Abstract: A piston head has opposite fluid drive surfaces and is enclosed in a cylinder housing also having opposite fluid drive surfaces. The piston head is secured to a piston rod anchored at one end to a stationary support whereby the piston head and cylinder housing produce driving movement of the cylinder housing. The cylinder housing has a work engaging arm on the exterior thereof. Fluid supply conduits lead into the piston head and open between the fluid drive surfaces. Control valves are provided between a pressured fluid supply and the piston head and include cycling controls providing advancing and retracting movement of the cylinder housing for reciprocating operation of the work engaging arm. A cycling operation is initiated by a normally closed spring return operating valve.

Abstract: A chemical pump actuator utilizes a variable pilot for operation of the piston power unit and an attached chemical injector. The pilot structure includes a pair of valve assemblies for regulating the flow of a power fluid into and from the piston cylinder. Pressurization and depressurization of the diaphragmmatic pilot, as regulated by a control fluid flow independent of the power fluid flow, operates the power fluid inlet and outlet valve assemblies. This pressurization and depressurization of the pilot is regulated by control fluid inlet and outlet valve assemblies, these assemblies being cam actuated by the piston upon completion of the power and return strokes. Exhaust of the power fluid from the cylinder is regulated by a throttle assembly with the length of the stroke of the piston determined by a stroke control assembly. Accordingly, the piston cyclic rate and stroke can be independently adjusted presenting a pump actuator capable of a finely tuned control of the chemical injector attached thereto.

Abstract: A liquid motor is driven by pressurized wet glycol, received from an absorber of a natural gas dehydrating system, and utilizes the energy of the pressurized wet glycol to provide the primary source of energy for operating a pump for pumping of dry glycol from a reboiler to the absorber. A gas driven motor regulates the stroking rate of the glycol driven motor. The liquid motor and pump are provided by a single stage double acting piston in a cylinder with fluid intake and exhaust valving and passages to alternately fill and exhaust the motor side of the cylinder while the opposite pump side of the cylinder is simultaneously alternately filled and exhausted. A spool type valve rod, associated with the glycol driven motor, is operated by the gas driven motor to regulate the rate of reciprocation of the glycol driven motor and to provide a secondary source of energy therefor. Intake and exhaust of wet glycol to the motor side of the cylinder is controlled by gas applied to another spool type valve rod.

Abstract: In accordance with the present invention, a pumping unit (10) is disclosed. The pumping unit includes shell structures (20, 22) each having a diaphragm (32, 38) therein to divide the pumping chamber within the structure into first and second compartments. One-way valves permit material to travel from an inlet source to the first compartment and from the first compartment to an outlet source. Deflection of diaphrams provides the impetus to draw material to the first compartment from the inlet source and drive the material to the outlet source. The motion of the diaphrams is induced by a reciprocating piston assembly (94) within a cylinder (84). The motion acts through intermediate chambers (110, 112) filled with pumping fluid and acting on the opposite side of the diaphrams from the first compartments. This permits isolation of the piston from the material being moved to prevent contamination.

Abstract: A double diaphragm pump with a novel compressed air control means is described, in which, in addition to a main control valve piston for the control of the compressed air fed to the two air chambers of the diaphragm pump, a pilot control valve means is provided, which drives the main control valve piston pneumatically such that the main valve is retarded at approximately half of the length of its stroke, at which point the main control valve piston separates the two air chambers both from the compressed air inlet and from the exhaust air outlet, and instead connects them together for the purpose of pressure equalization. By this measure in conjunction with novel sealing means for the moving parts, the pressure losses are reduced and thus the efficiency of the pump is increased, the danger of icing up the air exhaust is reduced, and separate provisions for lubrication, such as oil mist lubrication, are dispensed with.

Abstract: A down hole pump operated by gas in which the fluid in the production conduit may first be gas lifted. The exhaust gas from the pump aerates the well fluids in the production conduit. The pump is controlled by a valve whose operation is in turn controlled by a pilot valve shiftable in response to operation of the pump.

Abstract: A reciprocating fluid pump has a dual piston element and dual diaphragms in fluid communication therewith. Full movement of the dual piston element in either direction of movement causes movement of a pilot valve which simultaneously vents a first working chamber located in the direction of movement of the dual piston element and occasions reciprocating movement of the dual diaphragms, thereby directing a pump power medium to a second working chamber to cause movement of the dual piston element in the opposite direction.

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: Pressure converting apparatus which automatically and continuously converts low pressure fluid into high pressure fluid comprises low pressure and high pressure cylinders which are coaxially connected, but have different effective bore areas, a co-working piston rod which reciprocates in the chambers of the coaxial cylinders, an automatic pilot valve operating mechanism disposed at the rear end of the low pressure cylinder, and a fluid supply mechanism for supply a bypassed fluid into the high pressure cylinder. Due to the difference in effective bore areas of the low pressure and high pressure cylinders and the automatic reciprocation of the coaxial piston rod in the chambers effected by the automatic pilot valve operating mechanism, high pressure fluid is constantly produced at the high pressure cylinder as the low pressure fluid is continuously supplied into the low pressure cylinder.

Abstract: A diaphragm air pump assembly pneumatically associated with a vacuum source and an atmospheric air source, comprises two diaphragms interconnected by a vertically extending rod to define two vacuum operational chambers and two pump chambers, two valves for controlling the alternative admission of vacuum to the vacuum operational chambers, and two normally closed valves operable in response to movement of the diaphragms in unison with the rod, each of two corresponding constituent parts being disposed and mounted in a symmetrical arrangement with respect to the central axis of the pump assembly. When the diaphragms are moved in one direction, one of two normally closed valves is opened to admit the vacuum into one of two vacuum operational chambers while admitting atmospheric air into the other vacuum operational chamber.

Abstract: A diaphragm air pump assembly in pneumatic association with a vacuum source and an atmospheric air source includes therein two vacuum operational chambers and two pump chambers defined by two interconnected diaphragms upon admission of vacuum to one of the vacuum operated chambers and atmospheric air to the other vacuum operated chamber the diaphragms are moved in one direction due to pressure difference thereby compressing and exhausting the air contained in one of the pump chambers as well as opening one of two normally closed valves. The vacuum is thus admitted into the other vacuum operational chamber while atmospheric air is supplied to one vacuum operated chamber, so that the diaphragms are moved in the other direction thereby compressing and exhausting the air contained in the other pump chamber as well as opening the other normally closed valve. A periodical reciprocation of the diaphragms will accomplish the pumping operation.

Abstract: A piston-cylinder combination having a piston arranged for reciprocating movement within a cylinder under fluid pressure, the fluid pressure being ultimately delivered to the sides of the piston with a connector rod from the piston controlling the movement of valves for the delivery of fluid to the piston. The fluid valves are alternatively exposed to fluid under pressure to insure proper opening and closure thereof. The valving combination from the alternate sides of the piston eliminates chattering or floating of the piston, particularly when the piston is under a "no load" condition.

Abstract: A small diameter fluid-driven pump for subterranean fluid sampling, and including an elongated cylindrical body formed by a centrally disposed control valve block assembly and a pair of hollow motor piston chambers on opposite sides of the valve block and joined thereto. Within the centrally disposed control valve block assembly in axial alignment with the motor pistons are a spool pilot valve and a spool fluid distribution valve. The spool pilot valve is constructed to obviate stalling during its reciprocation under the impress of a power fluid directed thereto, and it functions to control the shifting of the distribution valve to which it is internally connected within the valve block assembly.

Abstract: A demolition tool for breaking solid materials, particularly rock or concrete in tunnelling, mining, demolishing and excavating applications. The tool has a single impactor (1) of the projectile type which is driven by high pressure liquid towards the material to be broken. A gas pressure accumulator (2) is included for storing high pressure energy. This energy is transferred at a high rate through short, wide and streamlined channel means (8, 13, 57, 9), having high capacity and low flow losses, to the impactor (1). Valve means (7) is provided in the channel means so that the accumulator (2) can be recharged during the return stroke of the impactor, giving a high repetition rate. A low pressure annular accumulator (5) drives the impactor during the return stroke.

Abstract: The invention relates to a thrust device using a plurality of hydraulic jacks, and to the automatic control of a plurality of thrust jacks.Two differential jacks have resetting chambers which are permanently under hydraulic pressure. Associated with each jack there is a self-locking piloted valve placed in the active position by a push-rod at the end of a work stroke of the piston of the jack and restored into the inactive position by a piloted valve actuated by a push-rod 39 at the end of the return stroke of the piston to its starting position. In the active position the self-locking piloted valve controls the isolation from the supply of all the work chambers and the venting of the associated work chamber 14.

Abstract: A hydraulic valve mechanism for a hydraulic motor having a cylinder and a piston reciprocating therein, comprising a valve block having a valve face, a main and an auxiliary central exhaust ports, two main feed ports on opposite sides of the main exhaust port, and two auxiliary feed ports on opposite sides of the auxiliary exhaust port. A valve chest is sealed over the valve face and has aligned piston-receiving bores at its opposite ends, a chamber for pressurized hydraulic fluid between the bores and a valve-actuating piston slideable in the bores. A main D-valve and an auxiliary D-valve operable by the valve-actuating piston move within the chamber in sliding sealing engagement with the valve face. The main D-valve covers and uncovers the main exhaust port and main feed ports to control the reciprocation of the motor piston.

Abstract: An air compressor for inflating pneumatic tires of a motor vehicle is particularly adapted to be powered by the negative pressure created at the intake manifold of the vehicle engine. The piston of a reciprocating air pump has a direct mechanical coupling with the plunger of a pneumatic cylinder assembly for driving the air pump. The cylinder assembly in turn is operated by the negative pressure of the intake manifold through a unique valve control system which automatically directs the negative pressure flow in a manner to reciprocate the plunger and hence, drive the air pump piston. In preferred forms, the plunger presents a greater operating area than the air pump piston whereby a pressure multiplying effect is provided to obtain the relatively high inflation pressures required for many pneumatic tires.