Abstract: A spaced apart apertured dual diaphragm fluid flow control device utilizes one flexible overcenter diaphragm to sense a variance flow condition and flex over center into engagement with the other diaphragm where cooperative apertures in the diaphragms cut off or regulate fluid flow through the device. Electrical circuit means are provided for an operational signal.

Abstract: A safety valve which prevents the discharge chute from rapidly falling due to a sudden loss of hydraulic fluid pressure. The valve is located between the chute lift cylinder port and hydraulic system hose. The valve is actuated when the flow leaving the chute lift cylinder exceeds a predetermined flow. The valve immediately stops the hydraulic fluid from leaving the chute lift cylinder maintaining the position of the discharge chute.

Abstract: A two way fluid flow check valve includes a plug movable reciprocally lengthwise of the valve against either of respective valve seats within a valve housing. A fixed partition which acts as a piston is located within a cylindrical cavity of the plug. The plug is slidable on a pair of hollow tubes centrally of the housing, the tubes supporting the fixed partition therebetween. The tubes provide respective fluid passages from either end of the housing into the plug cavity on the opposite side of the partition. Upon leakage in the pipe on either side of the valve, the plug will move in response to internal and external fluid pressures from the opposite side, towards the direction of lowered fluid pressure, and will seat against a mating valve seat at that end of the housing, thereby closing the valve.

Abstract: Safety valve, characterized in that it principally consists of a housing (1), provided with an inlet (2) and and outlet (3); a main cut off valve (4) installed in the housing (1); and means working together with the flow of liquid which with the removal of liquid and after a lapse of time shut the main cut off valve (4), which are reset in their starting position each time an equal or almost equal pressure in the liquid is created at the inlet (2) and outlet (3) of the safety valve and which when the main cut off valve (4) is shut, hold it shut as long as a well defined drop of pressure remains in existence over the main cut off valve (4), whereby these means are driven by means of a by-pass, such by means of a channel (6) that is situated apart from the main passage (5).

Abstract: Disclosed is a new and novel poppet type safety valve useful in flow conduits in fluid storage well systems. The safety valve is programmable to automatically close at various predetermined ratios of production mass flow rate-ambient pressure to prevent undesirable high flow rates or uncontrolled out-flow of fluid stored in a reservoir if the flow conduit or wellhead is damaged. This safety valve is lowered into and locked and sealed in a landing nipple in the well conduit. The safety valve has a variable bias which biases the valve member toward open position and a variable flow restrictor which is automatically actuated by a sensing actuator continually sensing reservoir pressure to vary the restricted annular flow area between the valve housing and inside of the well conduit for closure at the desired flow rate. The valve element has a through flow passage with locking recesses in the flow passage into which the sensing actuator may be releasably locked.

Abstract: A retrievable subsurface safety valve positioned in a well conduit is actuated to close by a predetermined flow rate through the safety valve. A valve member having a sealing surface is moveable by flow to sealingly engage an annular seat in the valve, closing the valve to flow. All forms of the invention safety valve have retrievable variable weight assemblies which releasably lock in the valve member for varying the flow rate at which each valve closes. In two invention forms, the weight assemblies when retrieved from the valve members leave the valve members open for passage of well tools through the valve members. In one invention form, the valve housing has a variable bias for biasing the valve member toward open position and this safety valve may be operated to expend the seat, housing and valve member with or without the variable weight assembly.

Abstract: A flow and pressure responsive valve which blocks upstream flow in the event of a break in a downstream line. Included is a solenoid valve positioned adjacent an inlet port, a pressure sensitive switch, and a velocity fuse positioned adjacent the outlet port. The pressure sensitive switch is tied to a cavity in common with the solenoid valve. The pressure sensitive switch activates the solenoid valve at a predetermined pressure threshold to permit the fluid to flow through the inlet port. The velocity fuse is calibrated to permit the fluid to flow at a nominal flow rate and when the fluid flow exceeds this rate, the velocity fuse shuts off fluid flow through the outlet port.

Abstract: Valve device, comprising a valve housing (1) with an inlet (3) and an outlet (5), a valve seat (13) and a valve closing member (8) movable in the housing between open and closed positions and having a sealing surface, which in the closed position of the valve closing member (8) is in contact with the valve seat to prevent liquid from flowing through the outlet. The valve closing member interacts with structure (15, 17) which, responsive to tilting of the valve housing relative to a predetermined position, moves the valve closing member to its closed position. The valve closing member being fixed to a float (11), which, as the liquid level rises in the housing (1) in its predetermined position, lifts the valve closing member towards its closed position, the weight of the structure (15, 17) being adapted to the lifting force of the float, so that the valve body, when the housing is filled with liquid and has been turned 180.degree. from the predetermined position, is held in its closed position.

Abstract: A safety valve which prevents the discharge chute from rapidly falling due to a sudden loss of hydraulic fluid pressure. The valve is located between the chute lift cylinder port and hydraulic system hose. The valve is actuated when the flow leaving the chute lift cylinder exceeds a predetermined flow. The valve immediately stops the hydraulic fluid from leaving the chute lift cylinder maintaining the position of the discharge chute.

Abstract: A safety check valve for use with a pumping unit for an oil well includes a ball housing in communication with a valve housing, a ball contained in the ball housing moving into the valve housing upon the breakage of a polished rod, whereby the ball seats upon a seating surface and seals off the oil well from the atmosphere.

Abstract: A Double Action Check Valve is shown provided with a flexible membrane secured between the inlet and outlet members, the membrane having apertures or orifices interiorly of the perimeter; substantially ball-shaped members centrally carried on either side of the membrane and under increased volume of flow from the inlet or outlet side of the ball-shaped members carried by it move in concert with the membrane as the membrane is caused to bow out or flex on either side of the coupling member as dictated by the volume of flow.

Abstract: A housing containing an air pump and an air pressure supply system for supplying air to a body support, such as an air mattress. The housing contains, in addition to the air pump, diaphragm type pressure regulators and diaphragm type surge check valves, as well as passageways and pressure chambers for interconnecting the pump to the pressure regulators and surge check valves.

Abstract: Fires caused by the leakage of lubricating oil spraying under pressure from lubricating oil conduits feeding bearings are controlled by stopping the flow of the lubricating oil in response to greater than normal flow of the oil through the conduit and simultaneously shutting down the machine having the bearing to which the oil is fed. A valve mounted in each conduit includes a valve element movable in response to the greater than normal flow through the conduit from a first position, to which it is biased and in which it is spaced from a valve seat, to a second position in which it engages the valve seat. A magnet mounted on the valve element actuates a magnetically operated switch connected in a circuit for shutting down the machine when the valve element moves at least part way from the first position to the second position. An alarm is activated as the machine is being shut down.

Abstract: A gas heated tool such as a soldering iron has a refillable gas container (1) with an inlet valve (17, 18, 19) and an outlet valve (14) biassed mutually to the closed position by a spring (21) acting between them. The outer valve is opened by an operating member (31) which is connected to a diaphragm (30) forming part of a differential valve. This is controlled by a rotatable tube (39) with pins (43) engaging a profile on an axially movable cam member (38) which acts on the operating member (31) through a spring (37). The control tube (39) has its upper end apertured (57) to control the admission of air in accordance with its angle of rotation. Thus, the rotation of tube (39) simultaneously adjusts the differential valve to control the flow of gas from container (1), and adjusts the mixture by adjusting the air admitted. Gas passing up operating member (31) mixes with the air and is consumed in combustion head (4).

Abstract: A portable sprayer which has a resealable closure, a dispensing valve and a pressure-responsive filling valve attached to a receptacle. As the receptacle is filled with fluid through the valve, air which is entrapped in the receptacle pressurizes the container to facilitate dispensing the fluid. During filling, the inlet valve closes if the pressure of the liquid source to which the sprayer is connected exceeds that within the container by a predetermined amount. The inlet valve also closes when the filling hose is disconnected from the container in order to close the container.

Abstract: Disclosed is a control device for use in fluid systems. In one embodiment the fluid is a liquid. A substantially cylindrical housing has therein a symmetrical cavity. The cavity is divided in upper and lower chambers by a circular and planar diaphragm. The upper chamber housing wall has protruding therefrom a cylindrical boss having a port for admitting a liquid. The boss forms a valve seat. The diaphragm has a plurality of concentric corrugations surrounding a central planar integral valve member. A media port in the lower chamber housing admits media for putting pressure on the diaphragm. When the pressure exceeds a predetermined value, the valve member closes upon the seat and entraps liquid between the diaphragm and upper chamber housing. The liquid acts to cushion, conforming to the shape of the diaphragm, thereby preventing damage to the diaphragm.

Abstract: A hydraulic fuse or cut-off device divides fluid flow into: (i) a primary fluid stream; and (ii) a secondary fluid stream having a substantially constant, but small ratio of flow to said primary stream. The secondary stream exerts pressure on a timing piston which thereby monitors the entire flow and causes the fuse to cut-off when a predetermined volume of fluid has passed through the device. The fuse includes a regulating piston for building inlet pressure to a value sufficient to develop the power necessary to drive the timing piston. Greater simplicity of the component parts and decreased sensitivity to contamination results from the use of a small fluid orifice to control the secondary stream. This is achieved by fitting the regulating piston with an inwardly directed flange, just touching the peripheral surface of a slightly tapered, central pin--whereby the taper of the pin causes the orifice to be created as the regulating piston is caused to slide as a result of the primary fluid flow.

Abstract: A safety valve comprises a valve member which is movable against spring biasing force to close under a predetermined flow rate against valve seats and allow only a small bleed through the valve via slots. The housing consists of two parts which are adjustably connected together by a screw thread which includes a locking nut enabling the valve to be adjusted and set for operation over a range of different flow rates.

Abstract: An excess flow limiter for attachment in a flow path comprising a main body with a lower inlet chamber and an upper outlet chamber connected by a central vertical passage having an inlet end and an outlet end. A freely movable slide member is sealably housed in the central vertical passage and extends into the lower inlet chamber. The slide member comprises a hollow cylinder with a closed lower end having a flange with sealing means about the closed lower end to seal the inlet end of the central vertical passage. A support is mounted in the lower inlet chamber to support the closed lower end of the slide member that extends into the lower inlet chamber thereby supporting the slide member in the central vertical passage when necessary. A set of outflow apertures are provided in the side wall of the slide member above the flange to allow passage of flowable material from the lower inlet chamber to the upper outlet chamber through the hollow cylindrical interior of the slide member.

Abstract: A relieving valve for a fluid or liquid storage tank to permit release of pressure from inside the tank as necessary. A piston is movable within the valve to open the same to atmosphere as pressure builds up slowly therewithin. Upon occurrence of a sudden or rapid pressure rise in the tank, such as when the fluid therein surges against the valve, a snubber assembly in the valve is moved by said pressure rise to a partially closed position to impede the rate at which pressure can build within the valve and thus increase the time before which the valve opens to atmosphere.

Abstract: Disclosed herein is an automatic shut off valve for a sprinkler system which closes the water flow path whenever a sprinkler head becomes dislodged from a riser pipe. The shut off valve includes a valve seat and a valve element. The valve element is attached to the stem of a valve assembly, which further includes a flange positioned in the water flow path. The valve element assembly is held away from the valve seat by a coil spring into which the stem of the valve assembly extends. The stem further includes a plurality of openings to allow water flow into the center of the flange and out through openings in the stem and thereafter through the center of the valve seat. The spring is calibrated in length and compression such that, during normal water flow with a head attached, the spring is not sufficiently compressed to allow the valve element to contact the valve seat.

Abstract: A speed control valve is formed with a pair of cooperating inversely operating dashpots to control movement of a valve element in either direction so as to prevent sudden actuation upon change in fluid velocity or oscillation due to fluid flow changes. Bleeding of fluid into and out of the dashpots controls the speed of movement of the valve element.

Abstract: A fluid fuse is quickly operable to shut off fluid flow upon rupture or other failure of fluid conducting line or other structural member downstream of the fuse. The fuse is actuated during decompression fluid flow resulting from decompression of fluid and elastic contraction of structural components downstream of the fluid fuse. During decompression fluid flow, a valve member is moved from an open position to a closed position by two forces generated by a pressure differential caused by sudden decompression of the fluid and developed across two variable, sharp edge, viscosity insensitive orifices, positioned in series and separated by a flow cut-off and sealing surface. The closing force, generated by the pressure differential of the upstream orifice is dominant and increases with the displacement of the closing member in a predetermined manner, permitting the use of a high preload and high rate opposing spring, at relatively low pressure differentials.

Abstract: A hydraulic fuse closes flow of hydraulic fluid in a hydraulic line upon loss of downstream fluid pressure. The hydraulic fuse includes a housing having an upstream opening and a downstream opening and a poppet slidably mounted within the housing for opening and closing fluid flow between the upstream and downstream openings. A spool is slidably mounted within the poppet for opening and closing fluid flow between first and second ends of the poppet. The spool includes a head which is positioned within the poppet and a rod which extends outwardly from the second end of the poppet and into the housing. When downstream pressure is lost, differential pressure acting on the first and second ends of the poppet will move the poppet to close fluid flow.

Abstract: An automatically and independently operating safety device for triggering a total or partial closure of a guard or safety valve member when the velocity of a fluid circulating in a conduit attains a predetermined dangerous value. The device senses the static and total pressures of the fluid within the conduit and supplies these pressures which control the movement of a piston and rod wherein the movement of the rod in response to fluid velocities which are dangerously high will initiate the actuation of the safety valve.

Abstract: A control system for use on fluid conducting pipe strings in earth boreholes to permit cycling of fluid flow between preselected flow rates to change conditions downhole as a result of surface exercise of fluid flow controls. A resulting change of state downhole is indicated by a change in fluid flow related pressure detectable at the surface.

Abstract: There is disclosed a reset mechanism particularly adapted for use within a magnet valve in which the reset mechanism comprises a passageway within the valve housing connecting the inlet and outlet passages in which a reset valve normally interrupts a communication between the inlet and outlet side of the said reset passage to permit normal operation of the magnetic valve and to permit normal fluid flow through the inlet and outlet passages thereof prior to movement of said magnetic valve from its normally open to its normally closed position.

Abstract: A constant airflow control apparatus is connected to an air duct of an air conditioning system to keep the flow rate of air fed from the air duct constant. The apparatus comprises a rectangular pressure receiving plate slidably mounted on a guide shaft extending in one direction inside a passage of a housing. The plate extends substantially at right angles to the central axis of the housing so as to block part of the cross section of the passage. The apparatus further comprises a coil spring for urging the plate against the flow of the air, and two swinging plates swingably attached to two opposite side edges of the pressure receiving plate, individually. The swinging plates are adapted to change the cross-section area of an air passage defined between the swinging plates and the inner surface of the housing in a mode represented by a quadratic curve in accordance with a rectilinear change of the pressure of the air.

Abstract: There is disclosed a fluid control device including housing, a fluid flow passage therein, and a fluid outlet passage communicating with said fluid inlet passage. Within the housing is a reciprocating valve capable of permitting or precluding communication between the inlet and outlet passages, the valve constituting a ferromagnetic armature susceptible to receiving an electromagnetic induction of a magnetic axis along its axis of reciprocation, such a magnetic axis generally corresponding to the longitudinal center of a fluid-tight chamber within said housing within which the valve may reciprocate. The valve is provided with a flow-responsive first radial end face disposed within a region of communication between the inlet and outlet passages. A fluid control device also includes a magnetic stator wound about the housing in the region of the reciprocating valve when the valve is in its open position.

Abstract: In accordance with the invention, a full opening check valve is provided which will close in response sustained high velocity flow through the valve. In one embodiment, a downhole blowout preventer is provided having a rigid outer sleeve which may be interspaced within a casing string near its lower end for insertion into a bore hole. The downhole blowout preventer has an inner sleeve including an upwardly longitudinally collapsible tube within the outer sleeve. The tube may be composed primarily of rubber or the like. The inner sleeve includes a surface for developing an upwardly acting collapsing force responsive to the upward flow of well fluids through the blowout preventer.

Abstract: A runaway valve for an air-driven material pump that shuts off air flow to the pump when air flow rate exceeds a predetermined setting to prevent pump damage, wherein the valve includes a flow-responsive poppet valve member and an axially movable sleeve finely adjustable about a first position to select flow rate, and movable to a second position to interconnect the upstream and downstream sides of the poppet valve member to effect reset. A closed chamber with a vent hole buffers the upstream side of the poppet valve member from inlet pressure to delay valve closing and compensate for pressure transients. In its reset position, the sleeve isolates this chamber from inlet pressure to achieve faster reset.

Abstract: A gas safety valve is provided which has a valve chamber within a housing, and a gas inlet and outlet respectively communicating with an inlet and outlet end of the valve chamber. Valve means are disposed in the valve chamber for allowing gas to flow from the inlet to the outlet when the valve means is in an open position, and preventing gas flow when the valve means is in a closed position at either end of the valve chamber. The valve means may comprise a piston having a tortuous gas transmitting opening therein, the resistance to gas flow caused by the tortuous opening rendering the valve means responsive to slight variations in gas pressure differential between the inlet and the outlet. Resilient means are provided which extend between the outlet and the valve means.

Abstract: A fluid control device includes a reciprocating valve comprising a ferromagnetic armature capable of receiving an axis of magnetic polarity corresponding to its axis of reciprocation, the axis generally also corresponding to the longitudinal center of a chamber within said housing, said chamber having a greater radius than the radius of the valve which moves within the chamber. The valve also exhibits a flow-responsive rear radial end face located within a region of communication between said inlet and outlet passages. The valve further has a front end face capable of closing the fluid outlet passage of the device. Further provided is a bias and calibration means located in the housing and disposed co-linearly and distal-proximately to the valve, near the rear radial end face thereof, opposite to the flow-responsive rear radial end of the valve.

Abstract: In a fuel injection system having an injector which delivers fuel to an engine in discrete injection events, a valve assembly shuts off fuel flow to the injector if the fuel flow during an injection event exceeds a desired upper limit.

Abstract: The safety device makes it possible to cut the water supply off quickly when there is a very low flow of water such as occurs when there is a leak, to cut off the water supply after predetermined time with normal water consumption, and to cut the water supply off very quickly when a certain predetermined maximum flow is exceeded as would occur with a fractured pipe. The safety device is automatically returned to its initial position when the water consumption is stopped and the shut off is first indicated by a significant reduction in flow. The device can also be manually returned to its initial position after a shut-off.

Abstract: A shutoff valve for installation in a gas distribution line to interrupt the flow of gas automatically upon a drop in pressure in the line due to a break or the like. The valve includes a movable valve member actuated by a piston which is disposed in a cylinder in communication with the distribution line. The top of the piston includes a calibrated aperture which admits gas into the cylinder beneath the piston so that the pressure beneath the piston in the cylinder is substantially equal to the pressure in the line. However, upon a sudden drop in pressure in the line due to a break or the like, the flow of gas through the aperture is metered so that the pressure in the cylinder beneath the piston becomes greater than the pressure in the distribution line, causing the piston to shift upwardly and move the valve member into a position where it interrupts the flow of gas. The pressure differential on the valve member retains it in the closing position.

Abstract: A gas lift valve device of the differentially operated type, having a straight, non-tortuous flow passage therethrough, with a hollow valve stem providing a portion of such passage, said device having a floating seat which automatically moves to valve engaging position to check backflow, the area of said seat being larger than the area of a piston on said stem and arranged so that the valve will close at a first predetermined differential pressure and will open at a second predetermined differential pressure which is lower than the first.

Abstract: An anti-surge valve for installation in a cylindrical chamber permits a fluid to flow at low velocity into and out of a port that opens into the cylindrical chamber and is located on the concave wall of the cylindrical chamber, the valve preventing a high velocity flow of the fluid from the cylindrical chamber into the port. The valve includes a sealing tube that is positioned within the cylindrical chamber in juxtaposition with the port and coaxial with but spaced radially inward from the portions of the concave wall that surround the port. The sealing tube is maintained in this position by spacers surrounding the sealing tube and extending radially outwardly to the inner surface of the cylindrical chamber. The anti-surge valve is a unitary structure molded of rubber.

Abstract: The invention provides a conduit blow out preventer utilizing movement of an annular piston to selectively effect the reduction of flow through the blowout preventer to a pre-determinable value or alternately, terminate flow therethrough altogether in response to the occurence of a pressure fluctuation in the fluid conduit to which the conduit is attached. An annular fluid conduit is defined between the interior bore of the annular piston and a support post. A discontinuous annular sealing element is provided in such fluid passage to provide an orifice, creating a pressure differential across the piston in the event of a biased flow surge. Axial movement of the annular piston results in closing of the outward fluid flow in the annular fluid passage and flow is then restricted to that permitted by a radially disposed orifice communicating with the annular fluid passage. A check valve in a fluid inlet is normally held off its seat by a connecting rod extending to the support post.

Abstract: A fluid fuse operable to shut off fluid flow upon rupture of fluid conducting line downstream of the fuse. The fuse is actuated by two forces generated by pressure differential caused by sudden decompression of the fluid and developed across two variable, sharp edge, viscosity insensitive orifices, positioned in series and separated by a flow cut-off and sealing surface. The closing force, generated by the pressure differential of the upstream orifice is dominant and increases with the displacement of the closing member in a predetermined manner, permitting the use of a high preload and high rate opposing spring, at relatively low pressure differentials. The sealing surface of the fuse is provided with limited freedom of alignment to permit tight sealing. The fuse assembly includes a manually adjustable bypass arrangement and a pressure peak attenuating control.

Abstract: An axial flow passageway includes a bulbous chamber (8) that is circular in cross section and has a smoothly curved sidewall that blends into the fluid line in which the fuse (2) is installed. The cross-sectional diameters of the chamber (8) increase from a predetermined diameter at the inlet and outlet ends to a maximum diameter at an intermediate portion of the chamber (8). A circular plug (12) is concentric with the axis of the flow passageway and has a maximum diameter equal to said predetermined diameter. The plug (12) moves in the axial direction between an intermediate equilibrium position and first and second closed positions in which the plug's periphery seats against the sidewall of the chamber (8). In the equilibrium position, there is an annular flow passageway between said periphery and said sidewall. A spring (22) biases the plug (12) in its equilibrium position.

Abstract: A hydraulic fuse for shutting off the line flow once the flow through the line reaches a certain maximum predetermined value. The spring biased movable closure element of the fuse is actuated by two force generating members positioned in series, the upstream of those members generating high actuating force, rapidly increasing with the displacement of the movable closure and configured to be relatively independent of fluid viscosity. The rate of increase in the actuating force, in respect to the displacement of the closure, can be selected at any desired level permitting the use of high rate of the biasing springs and resulting in fast enough response to trigger the fuse action by flow transient, due to the decompression of hydraulic fluid caused by a ruptured line.

Abstract: A safety valve for isolating a portion of a service conduit from a vacuum generator should a leak occur in that portion of the service circuit. The safety valve has a housing with a chamber therein. The chamber has an inlet port connected to the service circuit and an outlet port connected to the vacuum generator. A wall member located in the chamber is biased by a spring toward a first position whereby the vacuum generator is connected to the service circuit. Should a leak occur in the service circuit, air flow through the chamber acts on the wall to overcome the resistance of the spring and moves the wall to a second position to seal the chamber and thereby interrupts air flow through the chamber to the vacuum generator.

Abstract: An adjustable velocity fuse for a hydraulic line including a poppet valve assembly having a shielded head so as to be responsive to changes in fluid pressure differential and having an external adjustment associated therewith.

Abstract: A safety device for controlling the excess flow of gas adapted to shut off the flow of gas when the flow of gas exceeds a predetermined level. The device comprises a cylinder having in one end a throat member through which the gas flows, and a plurality of orifices formed around the cylinder through which orifices the gas is delivered to the throat member and then to a burner; a ball disposed at the other end of the cylinder, the ball having one side subject to the supply pressure of the gas and the opposite side subject to the delivery pressure of the gas. When the flow or delivery rate of the gas exceeds the predetermined level that is determined by the flow capacity of the orifices, the delivery pressure of the gas decreases to allow the ball to be pushed by the supply pressure of the gas so as to close the throat member, thus shutting off the flow of the gas.

Abstract: A hydraulic control system with a pipeline antiburst safety device for a double acting drive cylinder, more particularly for adjusting and securing the position of a driven guide roller in the strand guide of a continuous casting plant which exerts an operationally conditioned reaction force, applied by the strand, on the piston of the drive cylinder.

Abstract: A safety valve (14) adapted to be inserted within a flowline (10) comprises an elongate valve body (16) having central bore (24) with a fluid inlet (40) and a fluid outlet (42) in fluid communication with the bore (24). A slidable valve element (50) having a fluid passage (62) therein is mounted within the bore (24) and is slidable between the seated and unseated positions. A stop member (108) is mounted on the valve body (16) for relative movement between extended and retracted positions and has a stem which extends within the bore (24) along the longitudinal axis of the valve body (16). During normal operation valve element (50) is in a seated position and stop member (108) is in a retracted position, and thus, fluid flows from the fluid inlet (40) to the fluid outlet (42).

Abstract: A face mask is connected to a source of breathing fluid through a pressure-demand regulator and a supply line. The regulator admits breathing fluid to the mask on demand and maintains a positive pressure within the mask at all times to prevent inflow from the surrounding atmosphere. The regulator has a flow capacity considerably greater than that normally required, even when gasping or breathing heavily. An automatic shut-off device in the supply line upstream of the regulator permits the peak flow of a predetermined breathing requirement but is responsive to abnormal flow conditions, as for example where the mask is removed from the wearer, to close the supply line and thereby prevent wasting of the air breathing fluid supply. The apparatus can be manually reset to normal operation and will reset itself after the mask is repositioned on the wearer.

Abstract: A pressure demand breathing apparatus having a facemask connected through a pressure demand regulator with a shut-off device that operates automatically to interrupt the supply of air to the mask when the facemask is removed. The device operates with a time delay to permit momentary user-induced high flow rates without interrupting the supply.

Abstract: A device for connecting a hydraulic pump or other pressure fluid source to a working cylinder or other fluid motor comprises a pair of concentric hoses and a safety shut-off valve. One end of the inner hose is connected to the cylinder and the other end is connected to the pump by way of the safety shut-off valve. The space between the hoses normally is unpressurized and is in constant communication with a cavity containing a movable element of the shut-off valve. An elevated pressure in the space between the hoses will actuate the valve element for closing the shut-off valve. A second valve element is movable to close the valve when subjected to fluid flow forces resulting from an excessive flow of hydraulic liquid through the shut-off valve.