Abstract: A control valve is provided for construction equipment having a holding valve which prevents the natural lowering of an operation apparatus due to the dead weight of the operation apparatus when an actuator is in a neutral position. The control valve includes a valve body, a spool, a holding valve, a control valve, and a pilot pressure control valve. The control valve can save manufacturing cost as well as allow better use of space for construction equipment.

Abstract: The present invention relates to a method for welding at least one foil in a packaging process using a welding assembly, comprising the steps of directing the foil into the welding assembly, holding the foil in at least one holding point of the welding assembly, welding the foil in at least one welding point of the welding assembly, and where a part of the foil is accumulated between the at least one holding point and the at least one welding point prior to welding the foil in the welding point. The present invention further relates to a welding assembly employing this method.

Abstract: A fluid-pressure pump 2 rotated by an electric motor 9 drives a fluid-pressure cylinder 3. A discharge flow restrictor 15 is provided in a discharge passage 12 through which a working fluid from the fluid-pressure pump 2 is supplied to fluid-pressure cylinder 3. A pilot-pressure-operated shut-off valve 4 changes over a connecting position A at which the discharge passage 12 between the discharge flow restrictor 15 and the fluid-pressure cylinder 3 is connected to the tank 10 and a shut-off position B at which the discharge passage 12 is disconnected from the tank 10, in response to a pressure P1 in the discharge passage 12 between the discharge flow restrictor 15 and the discharge port 24, thereby enabling a change-over between a loaded mode and an unloaded mode assumed at an fluid-pressure actuator unit 1 in response to an operation of the fluid-pressure pump 2.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid, a fluid actuator, and a tank. The hydraulic system utilizes a directional control valve to direct flow between the source, the actuator, and the tank. The hydraulic further utilizes a variable backpressure control valve to control the system backpressure.

Abstract: A railway brake cylinder includes a body (11?); a piston (13?) mobile relative to the body (11?) to act on a brake linkage and delimiting with the body (11?) a pressure chamber (10?) adapted to be supplied by a pneumatic pressure agent source; an auxiliary actuating member (26?) mobile relative to the body (11?) and the piston (13?), mechanically connected to manual operating elements to cause it to occupy either a rest position in which it is away from the piston (13?) or a pushing position in which it is in contact with the piston (13?); two orifices (73?, 51?) in fluid communication with the chamber (10?) and the atmosphere, respectively; and selective connecting elements (28?) between the two orifices (73?, 51?), the elements (28?) being mechanically connected to the auxiliary actuating member.

Abstract: An actuator with a simple function for the control of a friction clutch in the drive train of a motor vehicle having a cylinder/piston unit for generating the contact pressure of the clutch should be fast, inherently safe and nevertheless simple and inexpensive. For this purpose, a controllable pump (3) generates a pressure medium and makes it available to the cylinder/piston unit (1) via a self-regulating valve unit (2). A dump valve (8) consists of a sleeve (10) and a spring-assisted slide (12) therein. The sleeve has a first opening (11), through which the pressure medium can flow from the cylinder/piston unit (1). The slide (12) exposes the opening (11) in a first position and conceals the opening of a second position. The clutch is controlled in this way by actuating the electric motor.

Abstract: The invention pertains to an electrohydraulic servo door drive for operating a door, a window, or the like, with a hold-open function, where a valve is installed in the hydraulic circuit to implement the hold-open function. To create an electrohydraulic servo door drive which requires less space and can be produced at lower cost, it is provided according to the invention that the valve is designed as a hydraulically controlled hold-open valve.

Abstract: The present invention relates to a control apparatus of a hydraulic valve for holding load in which a drain line of a holding valve adapted to preclude momentary drop of load in a hydraulic actuator is substituted with a path in the interior of a directional control valve, so that a pipe line of a drain side functioning as a hydraulic hose and exposed to the outside is not needed in the present invention. The control apparatus of a hydraulic valve for holding load comprises a drain line adapted to allow hydraulic fluid returned during a switching operation of the sub-spool to flow in a pilot line of the side of a drain corresponding to the opposite side of a pilot line adapted to pressurize the spool of the directional control valve.

Abstract: For a valve arrangement of a pneumatically actuated, spring-loaded control cylinder, a non-return valve in pneumatic communication with the control cylinder piston chamber. At very low backpressures in the control cylinder piston chamber caused by leaks of the valve responsible for pressurization of the piston chamber, the chamber is vented by passage of a very small air stream via the non-return valve. In this way, leaks cannot cause a very slow pressure buildup in the control cylinder piston chamber, followed at some time by undesired shifting of the control cylinder. In contrast, in the case of normal pressure buildup, i.e., during switching of the pressurizing valve, the non-return valve is promptly closed and the pressure in the control cylinder piston chamber is not influenced.

Abstract: A valve and a device for actuating the rotation of a stand (4) of a motorcycle (2) comprising an hydraulic actuator (1) operating an actuating member (7) between a first and a second position bringing the stand (4) from a rest position (A) to a supporting position (B). A flow control hydraulic circuit (12-25) is provided allowing the return stroke of the actuating member (7) to the first position leaving the stand in the supporting position (B), whereby the stand can be brought to the rest position (A) independently from the actuating member (7). The device has the advantages that in case of lack of pressure in the hydraulic circuit the movement towards the rest position in which it remains is free as if the device does not exist. Moreover, it can be operated by a single drive and its encumbrance is minimal. Its installation on the vehicle, moreover, is not complex, and it does not have the drawback of the existing electromechanical systems.

Abstract: A working cylinder (A) having at least one working chamber (6, 7) defined by the cylinder barrel (1), at least one of the end sections (2, 3) and a piston (4), at least one supply port (9a, 9b) and a exhaust port (12a, 12b) for the working medium. The exhaust port (12a, 12b) has a valve (13a, 13b) that may be regulated by the pressure of the working medium, which is applied at the supply port (9a, 9b) in order to obtain a smaller dimension of at least the valve and to better utilize the already existing space, specifically within the cylinder, and to better and more efficiently adjust the output capacity of the individual elements. A valve (V), particularly a switch valve (W) of a rocker valve design has therefore at least one inlet (16) and at least one outlet (17a, 17b) for the working medium, as wells as at least one control port (18).

Abstract: A gas actuating device includes a housing having a gas applying chamber, an actuator chamber and a gas applying passage for communicating gas from the gas applying chamber to the actuator chamber. An actuating member having a first side and a second side is disposed in the actuator chamber, wherein the first side of the actuating member receives gas pressure from gas applied to the actuating chamber from the gas applying passage. The actuating member moves in a first direction in response to the gas pressure applied to the first side of the actuating member. A valve selectively communicates compressed gas from the gas applying chamber to the actuator chamber through the gas applying passage for moving the actuating member in the first direction, and a gas release passage communicates gas from the actuator chamber at the first side of the actuating member to an outside of the actuator chamber.

Abstract: A rodless cylinder rope tensioning apparatus maintains tension in an endless rope system operable for threading a web in a paper-making apparatus and includes at least one rodless cylinder having at least one yoke sheave attached to the internal piston in the rodless cylinder. A rope is stretched around an entry guide roller and the yoke sheave and is stretched by operation of the rodless cylinder, which selectively causes the piston to relocate the yoke sheave along the length of the rodless cylinder and apply a selected degree of tension to the rope. In a preferred embodiment a pair of entry guide rollers is provided in a frame containing a pair of parallel rodless cylinders, each having a yoke sheave independently movable along the respective rodless cylinder by operation of the corresponding rodless cylinder piston, to effect tensioning of a pair of ropes in the paper-making apparatus.

Abstract: This invention features a device for controlling the operation of a pneumatic actuator and a pneumatic actuator having such a control device. More particularly, the actuator control device of the instant invention includes a housing mounted to an actuator end cap, a solenoid valve disposed within the housing and a gas control valve that controls the pressurized gas admitted to and exhausted from the actuator for valve actuation. The gas control valve is responsive to the solenoid valve and is mounted to the housing. Preferably, the control device includes a position indication mechanism, disposed within the housing, that determines a prespecified position of the valve responsive to the movement of at least one and preferably two moveable actuator probes extending from the actuator end cap into the housing. The gas control valve is a spool valve that is pneumatically controlled by the solenoid valve.

Abstract: A controlling motor for moving a stem along an axis has a hydraulic actuator with a cylinder in which a piston that is frictionally linked to the stem is slidingly and sealingly mounted, as well as a compression spring that is frictionally linked to the stem and acts against the actuator. The controlling motor has a trigger with an inflow area into which hydraulic fluid may be introduced, a pressure area that communicates with the inflow area through a diaphragm and is connected to the actuator, and a drainage area from which the hydraulic fluid may be evacuated without pressure, as well as a switching element that links the pressure area to the drainage area when a positive pressure differential occurs between the pressure area and the inflow area, and that otherwise shuts off the drainage area. The stem may be pushed out of the cylinder by the compression spring and may be drawn into the cylinder when hydraulic fluid is applied to the inflow area.

Abstract: A control system for a press having a clutch and a brake includes a clutch control valve and a brake control valve. The clutch control valve operates the clutch by supplying pressurized air to the clutch. The brake control valve operates the brake by supplying pressurized hydraulic fluid to the brake. The brake control valve is activated by pressurized fluid from the clutch control valve in order to insure simultaneous release of the brake with engagement of the clutch as well as simultaneous application of the brake with disengagement of the clutch.

Abstract: A pneumatic cylinder, especially for a spot-welding machine, has a sleeve valve mounted on the piston rod. The sleeve valve provides a venting valve for dumping pressure from a return chamber at the end of the forward stroke, and a progressive restrictor to close off a forward chamber and provide cushioning at the end of the return stroke.

Abstract: An engine for driving a piston arrangement for pumping water from an inlet to an outlet at a higher level is disclosed. The engine includes a hollow housing having an inlet and an outlet between which liquid passes, the housing at least partly enclosing a chamber through which the liquid flows from the inlet to the outlet. A movable wall is mounted in the housing and partly defines the chamber. A valve is provided to open and close the outlet so that when it closes, liquid in the chamber is suddenly decelerated producing an increase in pressure in the chamber to force the wall to move to a direction so as to increase the volume of the chamber. After an initial increase in the pressure, the water relaxes and the pressure decreases to such an extent that a spring will open the valve and the spring returns the wall to the position of decreased volume in the chamber. Thus, the wall is caused to reciprocate under the influence of pressure of the liquid increasing and decreasing as the valve is opened and shut.

Abstract: This actuating drive (1) for a control valve (2) has a control circuit which sets the actuating drive (1) to correspond with a specified required value from an overriding installation control system. It has, in addition, a main piston (6) sliding in a main cylinder (5) with a drive volume (7), on one side of the main piston (6), which can be acted on in a controlled manner by oil under pressure and has a plate valve (17) fitted upstream of the drive volume (7).The intention is to create an actuating drive, for a control valve, whose dynamic behavior can be improved by relatively simple means. This is achieved by the plate valve (17) being provided with a separate reservoir volume, connected to a drain appliance, for the oil emerging from the plate valve (17).

Abstract: A pneumatic circuit prolongs a pneumatic valve opening time using an accumulator with two quick exhaust type valves in series while providing a rapid valve closing time. This structure and method is self-contained and amenable to retrofit in existing installations without any external connections. Slow opening is achieved by routing inlet gas pressure simultaneously to an accumulator and the operating cylinder of the valve to be opened. A tortuous piping path and increased volume to be pressurized due to the addition of the accumulator substantially reduces the isolation valve opening time, thereby eliminating problems associated with quick opening of a pneumatic valve. When the pneumatic valve needs to be closed quickly, slight venting toward the inlet valve immediately causes the quick exhaust valves to vent their downstream pressure. The accumulator then vents through its quick exhaust valve while separately the main quick exhaust valve quickly vents the air cylinder of the pneumatic valve.

Abstract: This operating mechanism for a hydraulic actuator (2) having a pressure-proportional actuating signal is provided with an amplifier (33) for electric signals, with at least one electrohydraulic transducer (24) connected upstream of the hydraulic actuator (2) and with a hydraulic discharge amplifier connected between the electrohydraulic transducer (24) and the actuator (2). The aim is to provide an operating mechanism for a hydraulic actuator having a pressure-proportional actuating signal which can be produced simply and cost-effectively. This is achieved by interconnecting between the actuator (2) and the hydraulic discharge amplifier a piston/cylinder arrangement (4) acting as a transducer.

Abstract: In a method and a configuration for operating a hydraulic drive, a 3/2-port directional seat valve, which is driven by solenoid coils, controls an application of high-pressure fluid through a working piston of a piston/cylinder system. In order to increase the circuit-breaking capacity of the working piston, a hydraulic booster valve which is driven hydraulically by the 3/2-port directional seat valve is used for clearing a direct path from the piston/cylinder system to the low-pressure reservoir during switching-off.

Abstract: The present invention comprises a double acting actuator having a piston movable within a cylinder, a main poppet control valve connected to a fluid pressure source, and first and second poppet valves connected in series to a rod side chamber of the cylinder. The piston is extended upon actuation of both first and second poppet valves, while allowing retraction of the piston upon release of either the first or the second poppet valves.

Abstract: A hydraulically operated device including a single-acting cylinder having a piston for operating a working tool, a pressure chamber for applying a hydraulic pressure to the piston from an original position to an operated position, and a return spring for biasing the piston toward the original position. The device includes a hydraulic pump for delivering a pressurized fluid to be fed into the pressure chamber of the cylinder, and an automatic drain valve for inhibiting the pressurized fluid from being discharged from the pressure chamber while a difference by which a delivery pressure of the pump is higher than a pressure in the pressure chamber exceeds a predetermined value. When the difference becomes smaller than the predetermined value, the automatic drain valve is operated to allow the pressurized fluid to be discharged from the pressure chamber. Thus, the automatic drain valve automatically drains the pressure chamber when the pump is turned off.

Abstract: A pneumatic operated fastener driving device having a trigger valve and an improved main valve with a flexible membrane that controls the flow of compressed air to and from the cylinder. The flexible membrane maintains the main valve close no matter when the tool is connected or disconnect to an air supply line. Further, the main valve including the flexible membrane are designed and constructed to undergo a high number of tool cycles to provide long wear and low maintenance.

Abstract: An air spring apparatus has quick pressure release, and rapid air exhaust, capability by means of a relatively large diameter exhaust port in a larger, primary air spring which is controlled by the action of a smaller, secondary air spring. The secondary air spring is equipped with a check valve which controls the flow of air into the primary air spring. The rapid exhaust of the primary air spring is effected by triggering the removal of air pressure from the secondary air spring through a plurality of orifices in a centrally disposed guide tube which permits the collapse of the smaller air spring and the accompanying removal of a valve plate from a relatively large diameter exhaust port of the primary air spring.

Abstract: A pneumatic percussion tool includes a head valve device including first and second head valves disposed in the body and movable in response to the pressure variation in the head valve chamber. The first and second head valves are positioned at a first position for preventing communication between the main air chamber and the percussion piston chamber while permitting communication between the percussion piston chamber and the outside of the body and preventing communication between the head valve chamber and the outside of the body when the compressed air is introduced into the head valve chamber through the change-over valve.

Abstract: A flow control device includes a control valve having a discharge line to be connected to a hydraulic motor, a supply line to be connected to a hydraulic pump, a first bleed-off control passage having a line connected to a tank, and a second bleed-off control passage having a line connected to the tank through a secondary control valve, a flow dividing valve provided in the supply line and having a first position for allowing a first desired flow of oil discharged from the hydraulic pump and a second position for allowing a second desired flow of the oil, and a selector valve operable for the secondary control valve and the flow dividing valve and having a first selection position for closing the secondary control valve and shifting the flow dividing valve to the first position and a second selection position for opening the secondary control valve and shifting the flow dividing valve to the second position.

Abstract: Quick drop valves are usable in hydraulic circuits in which fluid is expelled from a hydraulic cylinder due to gravity force acting on a load connected to the hydraulic cylinder. The present quick drop valve has a sleeve carried by a valve member for establishing an orifice through which the fluid expelled from the hydraulic cylinder passes. When the flow rate of the expelled fluid exceeds a predetermined flow rate, a differential pressure generated by the orifice causes the valve member to start moving toward a quick drop position. In so doing, the sleeve quickly establishes a more restrictive orifice to immediately generate a higher differential pressure to cause the valve member to quickly move to the quick drop position. The more restrictive orifice also causes a greater amount of the expelled fluid to be returned by the valve member to the expanding ends of the hydraulic cylinders, yet still allows sufficient flow therethrough so that the quick drop action can be stopped if so desired.

Abstract: A ball drain valve (2), for the piston space (33) of a rotary clutch disc (3) for releasing the clutch disc piston (32) from pressure generated by rotation of pressurized oil remaining in the piston space when it is bled, including an opening (220), at least two ball spaces (25, 26) and a ball valve (23) actuated by rotation and control pressure. The ball drain valve (2) has two stages coordinated with the engaged and the disengaged positions of the clutch and the two ball spaces (25, 26) have outer diameters (D1, D2) of different sizes so that the ball valve (23), when the multi-disc clutch (3) is engaged, is in ball space (25) of large diameter (D1) and, when the clutch is disengaged, the ball valve is in ball space (26) of small diameter (D2). This arrangement achieves a quick drainage of the piston space (33) past a large gap (250) when the clutch is disengaged and prevents very little pressurized oil from escaping past a small gap (260) when the clutch (3) is engaged.

Abstract: A hydraulic actuator for hydraulically actuating a clutch mechanism to selectively engage a clutch drum and a planetary gear unit of an automatic transmission is disclosed, which comprises a chamber defined by the clutch drum; a piston operatively disposed in the chamber to form a fluid work chamber; a drain valve including a drain bore formed in the piston having one end exposed to the fluid work chamber and a valve ball movably disposed in the drain bore in such a manner that when the fluid work chamber is filled with a pressurized fluid, the ball closes the drain bore; and a flow straightening structure exposed to the fluid work chamber and formed on at least one of the piston and a bottom of the fluid work chamber in order to suppress formation of vortex flow near a mouth of the drain bore.

Abstract: A work cylinder having an internally-disposed, automatically-operated drain valve disposed in one or both ends of a housing having a cylinder bore formed therein. A reciprocally-movable piston divides the bore into first and second pressure chambers. A drain chamber formed in one or both ends has a movable plunger member disposed therein. A first passageway allows fluid from the pressure chamber to act on one surface of the plunger. A pilot valve is partially formed on a bottom portion of the plunger and opens when fluid pressure is exhausted from the adjacent pressure chamber. A bias spring acts on the plunger to prevent closing of the drain valve upon initial pressurization of the adjacent chamber. This initial pressurization assists in purging additional moisture from the chamber until a threshold level is exceeded to close the drain valve.

Abstract: An emergency drain device for pneumatic cylinders which is integrated in an orientatable connection fixed directly to the cylinder body and comprises a valve which closes an orifice of the bolt of the connection, going to the atmosphere, when a control pressure is applied to the head of the bolt.This device is advantageously used in installations where a general isolating switch, controlled by the same control pressure, connects the general distribution line to the atmosphere, for example in the case of an emergency, when said pressure disappears.

Abstract: A hydraulic control system comprising a hydraulic actuator having opposed openings adapted to alternately function as inlets and outlets for moving the element of the actuator in opposite directions and a variable displacement pump with loading sensing control for supplying fluid to said actuator. A pilot pressure operated meter-in valve is provided to which the fluid from the pump is supplied and pilot pressure is applied to the meter-in valve for controlling the direction and displacement of movement of the meter-in valve and the direction and velocity of the actuator. A pair of lines extends from the meter-in valve to the respective openings of the actuator and a pilot pressure operated meter-out valve is associated with each line of the actuator for controlling the flow out of the actuator when that line to the actuator does not have pressure from from the pump applied thereto.

Abstract: A solenoid valve unit for the control of the supply of compressed air to an air driven load and controlling the letting off of such air from the load has a valve housing with a pressure port, a power air port, a let off port for the valve space and a further let off port for the load driven by compressed air. The further pressure let off port is opened up and shut off by a valve plate or thimble that is only moved by pressure. This design makes possible a compact form of the valve so that the pressure port, the power air port and the further pressure let off port are placed on only two housing faces.

Abstract: A solenoid valve has an air outlet or relief plate fixed thereon. The valve in keeping with the invention is so designed that only high pressure air flows are switched or controlled, one such flow being used for the pilot control of a large-size air outlet valve housed in the plate. A number of such valve units may be placed in a line on a mounting plate that has a common air feed duct with its branches for the different valve units.

Abstract: A pneumatic drive for actuating switchable devices such as valves and the like includes a cylinder and a cylinder base, the cylinder having an annular slot which extends in a plane transverse to the axis of the cylinder between an interior cylinder space and the outside. A piston is movable within the cylinder space and is connected to one end of a piston rod, the other end of the rod being coupled to the device to be actuated. A supply line communicates pressurized gas to the cylinder space to move the piston away from the cylinder base, while a spring biases the piston in the direction toward the cylinder base. An annular groove is formed in at least one of two annular surfaces which bound the annular slot in the axial direction, and a sealing ring is seated in the groove for axial movement so that the ring projects into the annular slot in response to pressurized gas communicated through a branch line into the closed end region of the groove.

Abstract: A pressure responsive relief valve closing responsive to clutch actuating pressure and opening responsive to centrifugal forces and a spring force to relieve residual pressure in the hydraulic actuator of a rotating clutch to avoid clutch drag.

Abstract: An apparatus for controlling a single action piston and cylinder having means biasing the piston toward a retracted position within the cylinder and having a non-return valve openable toward the cylinder connecting the cylinder with a fluid pressure source comprises a control valve and a proportional valve. The control valve has an inlet in fluid communication with a supply tank, an outlet in fluid communication with a supply tank, a control port in fluid communication with the fluid pressure source, and a control element movable between open and closed positions for controlling flow of fluid pressure from the inlet to the outlet. The control element is spring biased toward the open position and forced toward the closed position by pressure entering through the control port. The proportional valve regulates the pressure entering through the control port.

Abstract: A truck cab lifting system that utilizes a single action hydraulic actuator, mechanical screw, or the like, connected between a truck frame and cab to tilt or pivot appropriately the cab of a cab-over truck, to expose the truck engine compartment, and return. The invention includes locating the single action hydraulic actuator, mechanical screw, or the like, forward of the truck wheel to extend a push rod, screw end, or the like, from the end thereof that pivotally connects to the cab to tilt or pivot that cab around its hinge connection to the truck frame, to move across that hinge connection and to provide a speed restraint as the cab travels through approximately forty-five degrees (45.degree.) to where it is fully rotated, and for cab return to an engine covering attitude.

Abstract: A hydraulic circuit (32), for example, remotely controls a work element (14) and contains first apparatus (34), such as a master cylinder (42), which passes a fluid pressure signal through a fluid pathway (38, 40) in response to an input signal. Second apparatus (36), such as a slave cylinder (44), correspondingly delivers an output signal for controlling the work element (14). Temperature variation can cause fluid volume changes which disrupt synchronized operation of the master and slave cylinders (42, 44). Third apparatus (74) positions the fluid pathways (38, 40) in fluid communication with a tank (28) in the absence of the fluid signal. If the signal passes through one pathway (38, 40), that pathway (38, 40) is automatically blocked from communication with the tank (28). Thus, when the fluid signal is absent from the fluid pathways (38, 40), volume compensation occurs because of dilution of the fluid in the circuit (32) with the tank fluid.

Abstract: A control system for opening and closing the clam shell gates of a material placement bucket makes use of a selfcompensating back pressure fluid system with a double-acting cylinder and piston. An air receiver is filled with high pressure air while air at the same pressure is being applied to the piston in a gate opening direction. At the same time, air from the receiver flowing through a pressure regulator and simultaneous exhaust valve at a reduced pressure is applied to the opposite, or reversing, side of the piston, creating back pressure. Hence the differential pressure applicable in the forward acting direction is the gate opening pressure. Closing pressure is the reduced pressure which becomes effective when pressure on the opening side is diverted to exhaust. Speed of closing the gates can be increased by adjusting only the pressure regulator to supply a higher reduced pressure.

Abstract: A gas turbine engine has a power turbine driven by gas flow across a nozzle arrangement that includes a partial admission gate valve therein that is movable into and out of overlying relationship with a limited number of vanes of the nozzle in order to control power output therefrom during part load operation of the engine.

Abstract: A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

Abstract: This invention relates to a three-way hydraulic valve, stable in two positions, intended for distributing a liquid containing impurities, comprising a ball valve whose ball is located in the first way, the inlet for said liquid, and has a seat located between the first and the second way, the pressure of said liquid applying said ball on said seat, a conical needle valve, a calibrated spring applying said needle on a seat located between the second and third way, said seat being of diameter smaller than that of the seat of said ball valve, and a manoeuvring rod outside the valve body, with which said needle is fast and which comprises an extension abutting on said ball and maintaining it open when the needle is closed.

Abstract: Means for controlling the decompression of a pressure chamber, such as an actuating pressure chamber of mine cage holding apparatus, including an outlet passage adapted to communicate with the interior of the pressure chamber; a valve seat associated with the outlet passage; a movable valve member movable into and out of engagement with the seat, the valve member or a part movable therewith being adapted to obstruct the outlet passage during at least part of the travel of the valve member away from the seat with a resistance to the release of pressure from the pressure chamber which decreases with increasing displacement from the seat; a control fluid chamber; a control piston movable in the control chamber and adapted to urge the valve member towards engagement with its seat under the influence of fluid pressure in the control chamber; and a vent from the control chamber through which fluid can escape.

Abstract: A moisture collecting pocket is provided in cummunication with the lowest portion of an actuating chamber of an air actuated system wherein compressed air is alternately introduced into and exhausted from the actuating chamber. A valve device is disposed within the pocket and has a restricted flow path formed therein from the pocket through the valve device when it is in an opened position with the valve device being movable to a closed position blocking the flow path each time compressed air is introduced into the actuating chamber.

Abstract: An air-hydraulic blind-riveting tool has a chuck which is normally urged into a ready position by a spring and which is drawn into a retracted position by a fluid-operated piston connected via a hydraulic link to an air piston subdividing an air chamber of the tool into a front and a rear compartment. The front compartment is vented to the outside and the rear compartment is connectable via a trigger-operated valve to a source of compressed air. Thus when this rear compartment is pressurized the air piston is displaced forward and the working piston connected to the chuck is retracted. A valve is provided between the rear compartment and the atmosphere which comprises a valve disk displaceable by pressure in the rear compartment against a valve seat to prevent air from leaving the rear compartment but normally urged by a relatively stiff spring away from this valve seat.

Abstract: A control system for controlling the operation of a valve actuator. The system includes a control valve for conveying operating fluid to the actuator in response to an actuator control signal. A single conduit operably connected to the actuator control valve both supplies operating fluid to the control valve and conveys an actuator control signal to the control valve.

Abstract: Pressure- and flow-regulating valve for automatic- or semiautomatic-cycle lubricating systems, principally characterized by being provided with a longitudinal bore subdivided into three aligned sections: in the intermediate section whereof there is coupled, with guided axial sliding, a piston element whose straight section has an area smaller than that of the intermediate bore section so as to permit oil to flow between the piston and the wall of the intermediate bore section; by the lower end of the piston terminating in an axial rod whose diameter is smaller than that of the piston to permit insertion of a coil spring around said rod; there being provided that the rod terminates in a spherical cap, intended to plug the last section of the longitudinal bore communicating with oil discharge when oil flows toward lubrication circuit and to re-open it when oil flow is interrupted.