Abstract: A rapid exhaust valve for use in a blood circulation stimulator which supplies and exhausts an air to and from an air bag provided on the human body, thereby subjecting to repeated pressure application and release.A valve box, which is provided with an exhaust port on the circumferential wall thereof, is provided with a flexible band valve diaphragm therein. If a compressed air is supplied into said valve box through a compressed-air supply pipe, said valve diaphragm is pushed by the pressure to close said exhaust port and a part of said valve diaphragm is projected into an air bag from an opening communicating with said air bag to allow the compressed air flow into said air bag. When the pressure in said air bag reaches high, said flexible valve diaphragm is deformed so that it may close said compressed-air supply pipe to release said exhaust port whereby rapidly discharging the compressed air out of said air bag.

Abstract: A pneumatic spring for use in absorbing an external force by compressing gaseous fluid trapped therein. The pneumatic spring includes internal valves for recharging and for relieving excessive pressure. In one form, the pneumatic spring comprises an outer housing defining an open-ended outer cylinder and an inner cylinder slidingly and sealingly positioned in the outer cylinder. The inner cylinder has a cylindrical side wall and end walls and a rod extends from the inner end wall of the outer cylinder through the inner end wall of the inner cylinder. A piston is fixed on the rod within the inner cylinder, thereby defining a first chamber between the inner end of the outer cylinder and the inner end wall on the inner cylinder and a second chamber between the piston on the rod and the outer end wall of the inner cylinder. The chambers are isolated from one another.

Abstract: An inhalation valve for respiratory diagnosis and/or therapy is provided. A single rubber or the like diaphragm is mounted in a free floating fashion so that one portion would open upon inhalation, while the other portion opens upon exhalation. The valve body is of molded plastic construction and contains a tube of restricted area through which air flows upon inhalation with reduction in lateral pressure being measured to indicate the volume of inhaled air.

Abstract: A diverter valve assembly includes a valve body rotatably mounted in a cavity of a housing. The housing has an inlet connected to a water supply, a tub spout outlet, and a showerhead outlet. The showerhead outlet is connected to a showerhead via a riser. The valve body has a jet orifice in communication with the inlet and alignable with one of the outlets. The valve body also has a flange which rotatably seats an elastomeric sleeve. The sleeve, when the jet orifice is aligned with an outlet, is aligned with the other outlet. The sleeve and flange form a pressure chamber which is in communication with the inlet. When the sleeve is aligned over the tub spout outlet, and the water supply is turned on, the back pressure caused by the showerhead flexes the sleeve to seal the tub spout orifice. When the water supply is turned off, the elastomeric sleeve relaxes to allow water to drain from the riser to the tub spout without the valve assembly changing position.

Abstract: An air bubble hydromassaging apparatus having a blower housed in a control unit, a bubble grid adapted to be placed in a bathtub, and air tubing enclosing a check valve to connect the control unit to the bubble grid. The control unit is provided with a bushing type compressed air outlet and the bubble grid is provided with a bushing type compressed air inlet. The air hose has a connector fitting on each end by which it is detachably and airtightly connected to the compressed air outlet of the control unit at one end and to the compressed air inlet of the bubble grid at the other end. A check valve built into the connector fitting serves to obstruct passage through the connector fitting when the blower is inoperative and opens to permit passage through the connector fitting when the blower is operative.

Abstract: A precise pressure regulator includes a housing defining a bore having pressure and relief zones, a pressure port communicating with the pressure zone, a relief port communicating with the relief zone, and a control port. A follower is slidable and a spool is rotatable in the bore. The spool defines a first passage for communicating the pressure zone with the control port and a second passage for communicating the control port with the relief zone. A spring biases the follower in one direction tending to block the first passage. Pressure in the pressure zone biases the follower in the opposite direction tending to block the second passage. A step motor rotates the spool in discrete steps to precisely control its position, which position determines the level at which pressure is regulated.

Abstract: In order to avoid excessive wear between a sealing ring and a shaft, the sealing ring is provided with a biased sealing lip which is moved against the shaft by a pressure medium flowing into an infeed channel of the shaft. When not in use, the sealing lips are spaced from the shaft and serve to close off the pressure medium chambers of the feed device.In order to exhaust air, the flow of pressure medium is shut off to the feed device so that the sealing lips are sprung back against a projection of the device in spaced relation to the shaft. This permits the pressure medium to exhaust from the shaft through a gap between the shaft and the feed device.

Abstract: An improved third accumulator check valve is provided for the valve chamber which services feed oil to the release side of the intermediate servo cylinder of a turbohydramatic transmission system for motor vehicles wherein the intermediate band is released as direct clutches are applied. It comprises a positive seating valve in the chamber exhaust port, preventing exhaust port leakage which results in premature band application and clutch drag, and is characterized by a valve body which has more favorably disposed outer lift surfaces and an internal bore flow chamber with additional lift surfaces, said bore being provided further with a flow-released bore closure biasing the valve responsive to active flow pressure with assisted force into a continuously seated position.

Abstract: A two-way valve for use in breathing apparatus comprising a valve chamber having a supply end and a mask end, both ends having openings, a valve plate member of thin lightweight material freely movable within the valve chamber between the supply end and the mask end for closing respective openings, the valve plate member defining a flow axis and a generally circular opening centered on the flow axis, a plurality of support arms extending radially inwardly from the perimeter of the circular opening, the support arms defining and being joined together at a solid central hub, a plurality of stub members extending radially inwardly from the perimeter of the circular opening, a fastening boss extending from the central hub towards the mask end of the chamber, retaining flanges on the boss spaced from the valve plate, a flat planar flexible valve membrane attached to the valve plate member, the membrane having a central opening fitting elastically over the boss, and fitting between the valve plate member and the fl

Abstract: An overpressure-control valve has a valve housing formed with a front output chamber, a back intake chamber adjacent and back of the output chamber, and a valve seat lying between the chambers. A valve body can move in the housing forward toward the valve seat into a closing position on the seat and blocking flow between the chambers and backward from the valve seat and into an open position permitting flow between the chambers. This body has at least one forwardly directed face and at least one backwardly directed face exposed in the chambers. The effective surface area of the forwardly directed face is greater than that of the backwardly directed face. A spring urges the valve forward into the open position with a predetermined generally constant biasing force so that the valve body moves back against the spring into the closed position when the backwardly effective pressure on the forward face overcomes both the force of the spring and the pressure on the back face.

Abstract: An oscillating or timing valve, sometimes known as an air relay, suitable for use with a chemical injector. A valve housing with sliding poppet, sliding piston and adjustable needle, with the poppet movable in one direction to close an exhaust port and with the piston movable in the opposite direction to engage the poppet and close the outlet or drive port and open the exhaust port. The piston oscillates between the drive port open and the drive port closed conditions, with the timing adjusted by varying the needle orifice and the size of the chamber fed through the needle orifice. The oscillating valve does not utilize any diaphragms or springs.

Abstract: A quick release valve for a vehicle braking system has an inlet port, an outlet port for connection to a brake actuator, and an exhaust port closed during operation of the actuator by a working area of a diaphragm. A support area of the diaphragm surrounding the area has peripheral indents with re-entrant edge portions. Reduction of the support area by formation of the indents lessens noise produced by the valve during exhausting after operation of the brake actuator.

Abstract: A valve apparatus for use in an intermittent gas lift subterranean well, having a reservoir with insufficient pressure for continuous delivery of produced fluids to the top surface of the well is disclosed. A valve apparatus carriable on a fluid transmission conduit has a flow passage for permitting produced fluids to flow through the transmission conduit from the reservoir. The valve is responsive to pressure to open the valve in the presence of a greater pressure exerted by the reservoir below the valve, and to close the valve in response to an even greater pressure generated by intermittent gas injection. A second flow passage selectively communicating with a radially extending port permits the flow of injected fluids from the tubing into the reservoir. A second valve, for selectively opening and closing the second flow passage, is spring biased in the closed position so that it remains closed when subjected to reservoir pressure, intermittent gas pressure, or their sum.

Abstract: An improved reversible quick exhaust valve is provided which comprises, in combination, a valve housing and a flexible resilient valve member disposed in the housing. The housing has a hollow interior and defines and entry port and first and second exit ports. A valve support is positioned in the interior to define with the housing a narrow passageway between the inlet port and the first exit port. The valve member is in the form of a flexible plate having a depending wall. The plate is disposed over one end of the valve support and the depending wall extends into the passageway. The plate blocks passage of liquid from the inlet port to the second exit port. The depending wall flexes during passage of the liquid from the inlet port into the housing and through the passageway to permit the liquid to pass out of the housing through the first exit port.

Abstract: Apparatus for rapidly achieving a desired pressure level in a tire by gas flow through a port in the tire such as the valve stem including a conduit having one end for connection to a source of gas under pressure and another end for connection to the inflation port. Valves are utilized for selectively closing and opening the conduit and for venting the conduit to the atmosphere. A selector whereby a desired pressure level to be achieved within the tire is provided as is a pressure level sensor which is connected to the conduit. A control in the form of a microprocessor digitally operates the valves to thereby provide for rapid inflation of the tire inasmuch as substantially full source pressure is applied to the tire to thereby provide a high pressure differential and increased gas flow.

Abstract: A regulator is provided for controlling air flow at high volume at either low vacuum or low pressure levels. The regulator includes an accumulator chamber having a first opening for providing flow of air from the accumulator chamber to a plenum and a second opening to facilitate air flow from either a positive pressure pump or a vacuum pump to the accumulator chamber. A regulator chamber is provided adjacent to the accumulator chamber for controlling pressure in the accumulator chamber, the two chambers being separated by a piston which moves in response to relative pressure changes in the chambers. This movement is controlled by means of a pressure transducer connected to the regulator chamber which controls air pressure to the regulator chamber through a valve by means of a comparison circuit which senses any difference between the pressure in the accumulator chamber and the desired pressure.

Abstract: A quick release valve comprising a main casting (1) and a closure member (5, 27, 45) crimped on after insertion of a rubber valve member (9, 30, 48) and an `O` ring seal (13, 39, 49).

Abstract: A vehicle power train of the type including a torque converter for coupling an internal combustion engine to a transmission, and a hydraulically actuated lockup clutch for bypassing the torque converter and mechanically coupling the engine to the transmission. The transmission is of the type having a plurality of hydraulically actuated shift clutches for selecting a desired speed ratio and a desired direction of vehicle travel. During each shift of the transmission a pressure control valve arrangement acts to temporarily drop and then gradually increase the pressurized fluid delivered to the transmission and to the lockup clutch. Interposed between the pressure control valve arrangement and the lockup clutch, a delay valve automatically closes to place the lockup clutch in communication with a fluid drain when the output pressure of the pressure control valve arrangement drops upon shifting of the transmission, and reopens when the output pressure rises to a predetermined level.

Abstract: A pressure reducing valve is constricted with a stepped piston affording a pressure responsive area on one side responsive to the pressure at an output port and a smaller pressure responsive area on the other side, contained between the seals of the two piston diameters and responsive to the pressure at an input port, the piston carrying a self lapping valve assembly connected via a passage to the smaller area for controlling the pressure at the output port in relation to that at the input port.

Abstract: A breathing valve for the selective entry of a gas to be inhaled and for the exit of exhaled gas, which utilizes a rolling diaphragm and flapper valves for its workings which are quiet and are constructed so as to be unlikely to freeze up or become sticky.

Abstract: A method and apparatus to control delivery of pressurized hydraulic fluid at a controlled pressure to open and close blowout preventers. A source of pressurized hydraulic fluid is connected through a pair of supply lines and through a control shifter valve for charging a closed system to a set-point pressure. A velocity fuse in each supply line diverts flow to one line if the other line breaks. Fluid from the source of pressurized hydraulic fluid is also delivered through a regulator valve to a regulated pressure line which is connected to one or more control valves. Each of the control valves is adapted to direct pressurized fluid selectively to either end of a blowout preventer actuator chamber.

Abstract: Pneumatic valve construction comprising a valve chamber having opposing inlet ports with opposing axially located valve seats, and a ball therebetween constructed and arranged to move off of one valve seat into engagement with the other valve seat upon an unbalance in pressure. The construction includes a bottom outlet port that extends to the top of another larger cylindrical chamber having an elastomeric piston therein with fluid flow clearance between the piston and the side walls of the chamber. A tubular exhaust port extends axially inwardly from the bottom side of the chamber to abut the bottom side of the rubber piston. An annular fluid flow chamber exists between the tubular exhaust seat and the side walls of the cylindrical chamber to allow flow past the piston through the space to a delivery port.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like. A unique two-stage, non-flowing pilot valve operates a main relief valve of substantially greater capacity. In a preferred embodiment main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to the main valve for operating communication therewith. A particularly unique ball selector provides means for testing both first and second stages without operating the main valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: This scuba regulator second stage includes the following improvements:(a) a diaphragm assembly using a pair of generally conical flexible diaphragms facing each other and clamped together about a portion of their periphery, the unclamped peripheral sections flexibly spreading apart to function as an exhaust valve;(b) a "detune button" which prevents inadvertent turn-on of the breathable gas supply valve during unattended use of the regulator, and which is automatically disengaged when the user begins to breathe through the regulator;(c) a case configuration in which the breathable gas inlet tube is situated very close to the regulator mouthpiece so as to minimize the torque loading on the teeth of the user as the user's head is turned;(d) a unitary valve configuration in which the entire breathable gas flow valve assembly is removable from the regulator case as an integral unit, without the use of tools;(e) a valve poppet configuration which prevents tilting of the poppet when the breathable gas flow control

Abstract: A pressure responsive pilot valve for a pressure relief valve of the type held closed by system pressure applied to a dome over the valve member. The pilot valve has an inlet port exposed to system pressure, an exhaust port and a control port connected to the dome. Below a set system pressure, the pilot valve interconnects the inlet and control ports to pressurize the dome. At the set pressure, the pilot valve interconnects the control and exhaust ports. The set pressure is adjustable by a sleeve threaded in the body and the blowdown is adjustable by a stem extending through the sleeve.

Abstract: An improved overall arrangement is provided for resuscitators of the class adapted for administering substantially pure oxygen from a pressurized source thereof, and especially those of the kind functionally employing a demand responsive type oxygen supply valve in conjunction with a manually compressible squeeze bag. The demand type supply valve is mounted on and communicates with the end of the squeeze bag opposite from the end thereof on which the patient non-rebreathing valve (and the face mask associated with the latter) is mounted and communicates with the bag.

Abstract: An automatic timer valve for irrigation plant includes a tubular differential-area piston which defines respective major-diameter and minor-diameter chambers in a hollow valve body. The chambers normally communicate through the piston to allow water to flow interruptedly from an inlet to an outlet. A build-up of back-pressure at the outlet acts against the major face of the piston and, overcoming the inlet pressure, advances the piston against a spring to cause abutment of the shutter disc and an annular shoulder. This abutment cuts off the flow, with the exception of a restricted passage, and puts the outlet into communication with a drain outlet. When the pressure in the outlet drops, the higher relative pressure at the inlet displaces the piston in a reverse stroke and uninterrupted flow recommences.

Abstract: Engine manifold vacuum is inverted by an in-line vacuum inverter which provides a power source for an EGR valve actuator for providing desired EGR flow in a predetermined range of engine power loading and EGR flow is cut off outside the range. The invention utilizes a vacuum inverter employing a pair of spaced diaphragms for controlling an atmospheric air bleed valve to a vacuum chamber powered by manifold vacuum. The diaphragms are spring loaded so as to seek equilibrium positions as vacuum in the chamber varies force. The inverter produces a vacuum output signal which changes inversely with changes in engine manifold vacuum.

Abstract: The present invention describes a vented check valve for use with post-mix carbonators. The vented check valve is a fail safe device which will vent carbon dioxide or carbonated water to the atmosphere when a back flow condition occurs. The vented check valve of the present invention includes a flexible valve diaphragm having a first valve seat portion around the annular portion of the diaphragm and a second valve seat portion in the center thereof. The first valve seat portion is utilized to open and close the main water inlet by permitting the edges of the diaphragm to flex in response to the pressure of water flowing in a first direction. The second valve seat portion is disposed in cooperation with a vent passage and seats firmly on the vent passage while water flows in the first direction, but unseats from the vent passage permitting the water to flow out of the valve, through the vent passage to the atmosphere when a back flow condition occurs, i.e.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like.A unique two-stage, non-flowing pilot valve (5) operates a main relief valve (7) of substantially greater capacity. Flow control elements provided by 35, 36, 38, and 39 associated with the first stage poppet are utilized to provide positive valve operation. In a preferred embodiment the main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to the main valve for operating communication therewith. A ball (16) selector, (24, 15, 76) provides means for conveniently connecting to a field testing either the pilot or the entire valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A shuttle type needle valve in a `T` shaped body. The needle has a beveled end and a piston which co-operate with a central tube to permit fluid flow selectively from either of the two opposite arms of the `T` shaped body to the central arm of the `T` shaped body.

Abstract: There is disclosed a system wherein a valve in a line is moved between flow controlling positions by means of a fluid-operated actuator. The admission and exhaustion of line fluid to and from the actuator is controlled by sensors which are automatically responsive to predetermined high and low pressure of the line fluid.

Abstract: An intermittent suction system for alternately applying a vacuum and atmospheric pressure to a patient for removing fluids from the patient and comprising a vacuum source and first and second containers adapted to be interconnected to the source and to the atmospheric pressure by a control unit that is adapted to apply the vacuum to the patient in response to a vacuum condition of the first container and to apply the atmospheric pressure to the patient in response to a vacuum condition in the second container, the control unit including structure for always interconnecting the vacuum to the patient when the vacuum condition in the first container is a certain percentage of the vacuum condition of the vacuum source regardless of the vacuum value of the vacuum source.

Abstract: A normally closed pneumatic valve and regulator assembly having regulator and vent valve spools is actuated by an operator pushbutton to automatically regulate pressure of a fluid provided from a pressure source. The valve assembly automatically vents when the pushbutton is released. A bias spring is operatively positioned between the pushbutton and one of the valve spools. The spring is preloaded by a pair of interlinked hook members which limits the travel of the pushbutton with respect to the valve spool and which maintains the spring in a preloaded condition so as to set a minimum value of regulated pressure. Fluid pressure from the pressure source urges the regulator valve spool into a normally closed position and the vent valve spool into an opened position. Pushing the pushbutton opens the regulator valve and closes the vent valve. The spring acts in opposition to fluid pressure on the combined valve spools to provide a regulated, reduced pressure for fluid exiting the valve.

Abstract: The device includes two movable members interconnected at their periphery by a flexible membrane defining therewith a tight enclosure of variable volume, a piston slidable in a cylinder integral with one of the two movable members and hydraulically actuated, to move the members apart from each other, a second cylinder separated in two compartments by an inner valve and controlling the actuation of the piston in response to the pressure of the water feeding said second cylinder, two apertures intermittently freed by the valve for releasing the piston and at least one aperture for the discharge of the water from the tight enclosure to the external water body when the piston release allows the two movable members to be urged toward each other, thereby producing an implosion which generates a strong sonic wave.

Abstract: A pair of interlocked flap valves within a faucet, such as a hose bib, provides for a fluid flow from a pressurized source through a discharge outlet while preventing a back flow to the source due to a lower pressure at the source than exists downstream as would occur within a resilient garden hose filled with water, sealed off, and being heated by the sun. A first flap valve, comprising a check valve, automatically closes when the main line pressure drops substantially or completely ceases, or by backflow pressures. When the check valve closes, an interlock connection thereof to a second flap valve, comprising a relief valve, simultaneously opens said relief valve relative to a relief port for outward discharge of the fluid. A manual control knob provides for selective "on-off" operation of the check valve.

Abstract: An apparatus for controlling the pressure in a tracheal cuff used with a tracheal tube to seal the walls of the trachea with respect to the tube, the cuffed tracheal tube being of the type used with an automatic respirator which cycles between an inhalation mode and an exhalation mode.

Abstract: A selector valve selectively communicates pressurized fluid from an inlet to an outlet and is adapted to be connected to a clutch of a transmission. The selector valve comprises a spool normally blocking communication between the inlet and outlet, a selector piston responsive to a control signal for movement towards the spool and a load piston reciprocally mounted in the selector piston and adapted to be moved thereby to control movements of the spool. A modulating orifice is interconnected between the outlet and the load piston to control movements of the spool for modulating fluid pressure in the outlet to a predetermined level.

Abstract: A respirator having a combination demand air regulator to provide air to the user on demand and an exhaust check valve. The regulator diaphragm, by its inward movement during inhalation, causes the exhalation valve to close while regulating the intake of supply air. Conversely, the regulator diaphragm, by its outward movement during exhalation, causes the exhalation valve to open while keeping the demand valve closed.

Abstract: Valve apparatus for use in connection with a respirator or like apparatus, suitable for use in resuscitation, the valve apparatus providing a stepless or continuous adjustment of the counter-pressure presented to expiration by the patient.

Abstract: A dual valve for an inhalation device which permits air to be withdrawn from the device upon inhalation but which prevents the flow of air into the device upon exhalation. The valve includes a central opening in communication with the device, and a plurality of openings about the central opening in communication with the surrounding environment. The valve also includes a central flexible flapper valve which extends across and controls the flow of air through the central opening, and a plurality of outer flexible flapper valves which extend across and control the flow of air through the outer openings.In use, inhalation by a user opens the central flexible flapper valve to allow the free flow of air from the inhalation device while the outer flapper valves remain closed. Correspondingly, exhalation by the user opens the outer flexible flapper valves from their seats to exhaust air to the surrounding atmosphere while the central flexible valve remains closed.

Abstract: A control valve arrangement implementing the use of pneumatic valves to control air flow for textile machinery blowdown, and the remote control of such pneumatic valves by means of remotely located solenoid valves. In air flow systems employing pneumatic valves of the type having a constrictable flexible annulus arranged within a rigid conduit with air under pressure selectively admissible to a space between the annulus and the surrounding conduit wall so as to effect constriction of the annulus to close off the passage through the conduit, solenoid actuated control valves have conventionally been employed to control the flow of fluid to said space between annulus and conduit to effect annulus constriction. Where these solenoid actuated control valves are located at control points which are remote from the pneumatic valve, it is found that the release of the annulus constricting air pressure is delayed due to the time delay between solenoid actuation and pressure change at the remote pneumatic valve.

Abstract: A pressure regulator has at least one solenoid valve operated by electrical signals connected to a container the actual pressure of which is indicated by a pressure electric transducer. A comparator generates a regulation signal which is the difference between the actual pressure and a command pressure signal. A regulator is connected to the comparator for generating a control signal to the solenoid valve in such a manner that the valve member of the solenoid valve is adjustable in a stable manner between intermediate positions within a range between the open and closed positions of the valve such that throttled pressure media continuously flows through the valve. The valve adjustment signal can be a continuously variable direct voltage which is proportional to the output signal of the regulator and may be a rectangular or saw-toothed voltage with a frequency exceeding the maximum actuating frequency of the solenoid valve.

Abstract: A fluid-pressure operated pilot valve produces a cyclic modulation of pressure in a control duct, for operating a relay valve, by introducing a predetermined delay between the displacement of a first valve element from, and its return to, a first position against a first valve seat by a fluid-pressure operated timer device, which includes flow restrictor means and a pressure accumulator, acting upon the larger area side of a differential area actuator which vents the pressure in the control duct to an exhaust duct in a second position of the first valve element; the relay valve being operable in response to the cyclic pressure changes in the control duct to admit an irrigating liquid to an irrigation spray nozzle.

Abstract: In a device in which a positive or negative pneumatic pressure source is coupled with a controlled system through a first electromagnetic valve and the controlled system is coupled with a negative or positive pneumatic pressure source through a second electromagnetic valve or opened therethrough to the air, and which is adapted so that the first and second electromagnetic valves are controlled to open or close to thereby set an air pressure in the controlled system, a deviation between the pressure of the controlled system and the set pressure is detected and the detected deviation signal is converted by a pulse converter into a pulse of the duty ratio or frequency corresponding to the deviation, by which pulse the first and second electromagnetic valves are controlled to open or close.

Abstract: A manually operable resuscitator includes a manually deflatable gas reservoir to supply gas to a hollow valve housing for controlled supply to and from a patient. The housing has three ports, a first one for connection to the reservoir, a second one for supply to the patient and a third one for exhaust to atmosphere. A distensable diaphragm which is distended by pressure in the reservoir to open the first port and close the third port. A non-return valve controls flow from the first port to the second port. The diaphragm may carry a valve to permit flow from the first to the second port if pressure drops in the latter as the patient inhales.

Abstract: This invention relates to an in-line back flow preventer valve for fluid supply lines of the reduced pressure zone type. The valve body has an inlet means and a discharge means for liquid flow therethrough. A first chamber, within the valve body, is in liquid communication with the valve inlet, with the first chamber having at least one outlet positioned in the periphery thereof. At the outer periphery of the first chamber is a first flexible member which is adapted to seal the peripheral outlet through elastic pressure under the static or back flow pressure condition within the valve. A second chamber commonly referred to as a reduced pressure zone is positioned outside the first chamber and has at least one outlet in the periphery thereof. Mounted at the outer periphery of the second chamber is a second flexible member adapted to seal the peripheral opening through elastic pressure when the valve is under the back flow or static pressure condition.

Abstract: An improved emergency system (10) for a vehicle having a closed center steering valve (12), a pump (14) normally supplying fluid to the valve, and an accumulator (16) for supplying emergency pressurized fluid to the valve when the pump fails. The improvement is a flow directing circuit (18) connecting the accumulator to the valve in parallel relationship to the pump and apparatus for blocking flow from the accumulator to the valve responsive to proper operation of the pump. Adequate emergency steering is provided to a closed center steering valve system by the above arrangement.

Abstract: A single small safety valve is furnished for use with hazardous machinery that requires simultaneous actuation and continuous pressure on two hand valves at points out of the danger zone of such machinery. Operating characteristics are achieved by a housing having an axial bore, a piston moving within that axial bore, input ports, output ports and an exhaust port located at suitable positions on the housing. The arrangement of these ports is such that open fluid communication can exist between the two input and output ports only if the input ports are pressurized within a small time interval necessary to retain the piston in a neutral position in the axial bore, and if said inputs are held to maintain pressurization during the time that it is desired to maintain pressure in the output ports. Operation of the hazardous machinery is contingent upon continuous pressurization at the output ports.

Abstract: A diaphragm assembly for the demand regulator of a breathing apparatus utilizes a diaphragm that gradually flattens down against a conical platform so as to reduce the effective sensing area. Advantageously the diaphragm is used in conjunction with an aspirator opening adjusted for maximum aspiration effect at low flow rates. At increased flow rates the reduced sensing area compensates for increased aspiration, insuring stable operation. The diaphragm periphery cooperates with the conical platform outer edge to serve as the regulator exhaust valve.