Abstract: A flexible, gussetted package having an interior for holding some particulate material product, e.g., food stuffs, under vacuum, and which includes a mouth to be opened to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, a pair of opposed side gussets and a pressure equalizing valve. The valve includes a displaceable slitted-aperture disk located on a valve seat and is arranged to operate in a first mode of operation wherein any gasses within the package are allowed to vent to the exterior of the package, by passing through the interface between the disk and the valve seat while the ambient atmosphere is precluded from entering into the interior of the package. The valve also operates in a second, transitory, mode wherein the slitted aperture in the disk allows a small amount of the ambient atmosphere to gain ingress into the interior so that the package's walls give a smooth appearance.

Abstract: A filtering apparatus is provided wherein the filter can be backwashed by an explosive-like surge of backwashing fluid. The backwashing assembly includes a quick-opening backwash valve which is not actuated by a linearly-acting valve stem disposed on the outlet side of the valve. In a typical embodiment, the inlet valve to the filtering apparatus is a rotating butterfly valve and the backwash valve is physically attached to the inlet valve, such that, when the inlet valve is open, the backwash valve is fully-closed and when the inlet valve is moved towards its fully-closed position, the backwash valve is fully-opened. The invention uses a two-step method of initially applying biasing pressure on the inlet valve/backwash valve combination and to thereafter provide additional pressure to dislodge the backwash valve from the valve seat--whereupon the backwash valve quickly opens and an explosive-like surge of backwashing fluid effectively backwashes the filtering media.

Abstract: A flexible, gussetted package having an interior for holding some particulate material product, under vacuum, and which includes a mouth to be opened to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets and a pressure equalizing valve. The valve is arranged to operate in a first mode of operation wherein any gasses within the package are allowed to vent to the exterior of the package, while the ambient atmosphere is precluded from entering into the interior of the package. The valve also operates in a second, transitory, mode wherein it allows a small amount of the ambient atmosphere to gain ingress into the interior so that the package's walls give a smooth appearance. The valve then enters into its third mode of operation wherein it isolates the interior of the package from the exterior.

Abstract: An automatic by-pass valving system for an electrical cable system wherein insulating fluid at a pressure above atmospheric pressure is supplied to an electrical power cable, such as a pipe-type or self-contained cable, having a fluid flow channel and having at least one hydraulic stop interrupting the flow of fluid between the channels of adjacent portions of the cable which are at different elevations. The valving system comprises a check valve, which allows fluid flow only in a first direction, from the lower elevation portion to the higher elevation portion, and a flow-limiting valve, which allows fluid flow only in a second direction, from the higher elevation portion to the lower elevation portion, at a reduced rate. Preferably, a relief valve is also provided to allow fluid flow in the second direction at a higher rate if the fluid pressure difference in the second direction is exceeded by a predetermined amount.

Abstract: A vent for conducting gas from the atmosphere to a space of a container, the vent comprising a manifold engagable to the container in gas communication and a breather intake assembly engagable to the manifold in gas communication and having a valve assembly operative for admitting ambient air into the container when subatmospheric pressure is present within the container.

Abstract: A check valve for use in an hydraulic control circuit includes separator plates each having an orifice of predetermined size and a ball retained between the separator plates, adapted to close one of the orifices and to open a port and parallel passages communicating with a chamber in which a ball is retained. The ball chamber is in continual communication with the orifice that is not closed by the ball.

Abstract: A controllable exhaust system of an internal combustion engine is shown which includes an exhaust gas inlet tube extending from the engine, a muffler connected at its inlet side to the exhaust gas inlet tube and having first and second exhaust gas flowing passages defined therein, and first and second exhaust gas outlet tubes respectively connected to the first and second exhaust gas flowing passages and extending from the muffler independently. A muffler controller is incorporated with the exhaust system for varying the flow passage area of the second exhaust gas outlet tube in accordance with the pressure of the exhaust gas led into the muffler from the engine.

Abstract: A device for controlling or metering fluid flow in either direction through a conduit. The device comprises an elongated body having two end walls forming an internal chamber therebetween. Each end wall further having an aperture extending axially therethrough. Disposed within the chamber is a free floating piston having a first metering orifice and a second metering orifice extending therethrough. Fluid flow through the device urges the piston against the end wall in the direction of fluid flow. In this position, the end wall in the direction of fluid flow closes off the second metering orifice while fluid is permitted to pass through the first metering orifice and into the aperture in the end wall in the direction of fluid flow. Upon a flow reversal, the piston is urged against the opposite end wall. In this position, fluid will flow through the second metering orifice in the piston and exit into the aperture in the end wall in the direction of fluid flow.

Abstract: A snubber is disclosed for use on an airplane translating door hinge arm (13) comprising a hydraulic device (41) and a flow regulation system (40). The hinge arm (13) includes sprockets (25, 27) placed at the ends (15, 17) of the hinge arm (13). Roller chain pieces (31) rotate partially about the sprockets (25, 27). A pneumatic actuator (33) having a through-rod (37) and housing (35) is located on one side of the hinge arm (13). The actuator housing (35) is supported by a support member (23) integral with the hinge arm (13). The ends of the actuator through-rod (43) are each coupled to first ends of each of the roller chain pieces (31). The hydraulic device (41) comprising a housing (47), a through-rod (43), a piston 45, a first compartment (49), a second compartment (51), and hydraulic fluid, is also supported by the support member (23). The ends of the hydraulic device through-rod (43) are each coupled to second ends of each of the roller chain pieces (31).

Abstract: In air-spring legs with a pressure chamber in each case for motor vehicles, in which the respective pressure chamber can be subjected to different pressures via a connector leading to the outside, a minimum pressure is to be ensured in the respective pressure chamber irrespective of external influences. This minimum pressure is also to be present in the case of a demounted or not yet mounted spring leg in the pressure chamber thereof. For this purpose, the connector of the pressure chamber of the air-spring leg has in each case an automatically operating pressure relief valve which can be designed to maintain a minimum pressure which can be predetermined for the chamber, and by means of which pressure relief valve the connector is open at a pressure which is acting from the interior of the pressure chamber or from the outside and is above the minimum pressure and, at a pressure below it, is closed.

Abstract: An apparatus is provided for controlling flow of fuel vapor and liquid fuel through an aperture in a fuel tank. The apparatus includes a housing mounted in the aperture and a vent valve movable in the housing to block flow of fuel vapor between the fuel tank and an outlet. The housing is further formed to include a float valve movable between a closed position blocking flow of fuel vapor and liquid fuel through the outlet and an open position allowing flow of fuel vapor through the outlet. The float valve includes a wide-diameter base, an upwardly extending closure appended to the base member, and a downwardly extending narrow-diameter weighted unit depending from the base. The base and the weighted unit are sized, shaped, weighted, and located to cause the float valve to "snap" (e.g. move quickly and suddenly) to its closed position after rising fuel in the fuel tank rises past the weighted unit and engages the underside of the base.

Abstract: A venting control system is provided for controlling discharge of fuel vapors from a vehicle fuel tank. The system includes a vent apparatus mountable in an aperture formed in the top wall of the fuel tank. The vent apparatus is formed to include a vapor inlet opening communicating with an interior region of the fuel tank, a vapor outlet opening, and a passageway interconnecting the vapor inlet and outlet openings. The system further includes a tubular skirt having an uppermost end coupled to the vent apparatus and a lowermost end and a fill-limit valve assembly coupled to the lowermost end of the tubular skirt. The tubular skirt and the fill-limit valve assembly are positioned to lie in the interior region of the fuel tank when the vent apparatus is mounted in the top wall aperture of the fuel tank.

Abstract: A fuel vapor control valve is provided for controlling the flow of fuel vapor and liquid fuel through an aperture in a fuel tank. The fuel vapor control valve includes a housing mounted in the aperture. The housing is formed to include an inlet in fluid communication with the fuel tank and an outlet. A valve is movable in the housing between a blocking position blocking flow of fuel vapor between the inlet and the outlet and a venting position allowing flow of fuel vapor between the inlet and the outlet. The fuel vapor control valve also includes a spring for biasing the valve toward its blocking position and a mechanism for using fuel vapor from the fuel tank to move the valve toward its venting position. A ball is movably positioned in the venting control chamber to selectively interrupt the fluid communication between the inlet and the outlet.

Abstract: A mouthpiece for a semi-closed type of breathing apparatus for removing carbon dioxide from breathing air circulating from an inhaling port to an exhaling port in a breathing circuit, comprising a casing, a diaphragm which expands when the inner pressure of a casing is increased through an exhaling operation, exhaling valve member for opening and closing the exhaling port, an urging device for urging the exhaling valve member in such a direction as to close the exhaling port, and a lever having one end linked to the exhaling valve member and the other end linked to the diaphragm, the exhaling valve member being opened through the lever when the inner pressure of the casing is increased through the exhaling operation and the diaphragm expands.

Abstract: An improved valve of the class referred to as capacity fuse valves which closes in response to passage of a total fluid flow volume through the valve to the valve outlet. The incoming fluid entering the valve inlet is split into a main flow that passes through a variable main flow metering port to the valve outlet and a control flow that passes through a variable control flow metering orifice and is utilized to close the valve upon passage of a predetermined main flow volume (main flow valve closure volume) through the valve. The areas of the main flow metering port and the control flow metering orifice are varied in response to the fluid inflow rate into the valve inlet and/or fluid temperature in such a way as to maintain a substantially fixed ratio between the main flow rate and the control flow rate, and thereby a substantially constant main flow valve closure volume, over a range of fluid inflow rates and/or temperatures.

Abstract: A bi-directional cracking valve that can be selectively opened. Bi-directional cracking valve (10, 70) is formed using an elastomeric membrane (34). Centered within the elastomeric membrane is a slit (36) that remains closed, blocking fluid flow through the device until a differential pressure across the elastomeric membrane exceeds a predefined cracking pressure, sufficient to force fluid through the slit. The elastomeric membrane is an integral part of an elastomeric cylinder (28), which is mounted in a valve carrier (12). The valve carrier includes ports disposed at opposite ends and the ports are adapted to couple to tubing. An operator can selectively enable fluid flow through the device by squeezing side tabs (40, 42) disposed on opposite sides of the elastomeric membrane together, forcing the slit open. A latch (46) is provided to keep the bi-directional cracking valve in an open state.

Abstract: A flow control valve having a housing in which an insert is positioned. Fluid flows around all sides of the insert. A guide cylinder is positioned within the housing on an inlet side of the housing. A shaft of a first spring-loaded control element is guided and axially displaceable in the guide cylinder. The first control element has a valve disk with a collar. The valve disk has at least one lateral bore. The collar is enclosed by a second control element which is formed as a spring-loaded control sleeve. The second control element is guided and axially displaceable in the housing. In a zero flow-through operating condition, a rim of the valve disk rests against a bottom of the second control element thereby blocking each lateral bore in the collar of the first control element.

Abstract: The disclosure relates to an improved diaphragm type mud saver valve, commonly referred to as a Kelley valve, which closes automatically to prevent loss and spilling of drilling mud. The improved valve can withstand very high drilling and pump pulsation pressures, for example, the pressures required for drilling wells over 20,000 feet in depth and mud pressures can exceed 15,000 p.s.i. The disclosure prevents the formation of gas pockets by providing gas escape openings and a clearance space between the support and backup element to prevent the extrusion of the diaphragm material through the small openings in a backup sleeve thus extending the life of the diaphragm and allowing proper diaphragm seating.

Abstract: A pressure relief valve selectively permitting fluid flow through the valve if the pressure on one side of the valve exceeds the pressure on the other side of the valve by a set amount, the pressure relief valve including a first valve member having a valve seat surface, and a movable valve member adapted to releasably engage the first valve member. The movable valve member includes a body portion having a periphery, the periphery having a downwardly extending annular flange engaging the valve seat surface. The downwardly extending annular flange includes a generally spherical valve surface adapted to provide a seal with the valve seat surface by engaging a resilient sealing ring on the valve seat surface. A flexible diaphragm causes movement of the movable valve member away from the valve seat when the pressure on the other side of the valve exceeds the pressure on the one side of the valve by a selected amount.

Abstract: An apparatus is provided for controlling venting of fuel vapor through an aperture in a fuel tank. The apparatus comprises a housing mounted in the aperture and a valve moveable in the housing between a blocking position blocking flow of fuel vapor from the fuel tank through the housing and a venting position allowing flow of fuel vapor from the fuel tank through the housing. A spring biases the valve towards its blocking position. A mechanism is provided for using fuel vapor from the fuel tank to move the valve against the spring towards its venting position. The using mechanism includes a venting control chamber receiving fuel vapor from the fuel tank in a conduit communicating fuel vapor from the fuel tank to the venting control chamber. The conduit includes a first portion and a second portion moveable relative to the first portion to define an intermediate portion.

Abstract: A method is disclosed for operating a valve needle for plastic processing plants. The needle valve may be controlled by a control valve, which in turn is controlled by a working gas volume in order to prevent formation of internal waviness in injection molded articles even under very high gas pressures and to assure high flexibility in production without refitting delays. During plastic mass injection the valve needle seals tightly. During gas return the valve needle remains open until the gas bubble in the mold cavity is completely emptied.

Abstract: A liquid fuel filter system for use in fuel dispensing stations including a ball valve assembly and replaceable strainer cartridge permitting strainer cartridge replacement even if the associated fuel pump is activated. The ball valve assembly seals the inlet port of the filter housing thereby disabling the flow of fuel through the housing when the strainer cartridge or filter housing cap are removed. A check valve prevents fuel from flowing back thorough the filter system outlet port into the filter housing. A pressure valve disposed in the check valve prevents possible harmful pressure build up.

Abstract: A pressure regulating inlet-and-outlet valve for a sealed space enclosed by a housing wall (10). The wall is penetrated by at least one gap (6) that is spanned by a magnetic field and completely occupied by a ferrofluidic liquid (7) confined inside the gap by the field.

Abstract: A breather valve connected to a breather passage for opening and closing a valve element to adjust the internal pressure of a sealed container corresponding to the pressure change inside the sealed container includes a valve bore, the valve element slidably fitted in the valve bore, a spring for pushing the valve element toward the sealed container, an elastic portion tapering toward the sealed container, a slit formed at the free end of the elastic portion, and a needle member extending from the side opposite to the sealed container toward the slit. Plastic deformation caused by pressure reduction inside the sealed container opens the slit while the needle member projects through and opens the slit when increase of the internal pressure of the sealed container pushes the valve element against the pressure of the spring.

Abstract: A normally closed pilot operated bi-directional poppet valve for controlling flow between first and second valve ports. When the pilot valve is closed, pressure is applied from whichever port is at the higher pressure to the poppet in a manner to hold the poppet closed. When the pilot valve is open, pressure is vented to whichever port is at the lower pressure in a manner to allow the poppet to open.

Abstract: A cardiovascular outdwelling, normally closed, pressure-responsive bi-directional slit valve liquid flow control and related methods wherein a diaphragm having a slit therein is flexed distally by hydrostatic pressure and proximally by negative pressure at different points in time to selectively open the slit and accomodate the flow of IV solution to a medical patient through a cannula and blood sampling from the cardiovascular system of the patient through the cannula in such a way as to prevent bleed-back and clotting of blood within the cannula.

Abstract: A hydrostatic drive system for vehicles including a hydromotor with a control unit forming together a drive unit which in the assembled state can be inserted in the seat of the centering device of the drive system, the configuration and arrangement of the wheel brake valve wakes possible to obtain a drive unit with compact dimensions, in axial as well as in radial direction, especially due to the double function of the wheel brake valve which serves simultaneously as a pressure relief valve.

Abstract: The bi-directional pressure relief valve comprising a valve casing defining a valve bore, a valve chamber at one end of the valve bore and a pressure chamber communicating with the opposite end of the valve bore. The valve chamber has a first port communicating with a first fluid line and a second port communicating with a second fluid line and the first port having a valve seat coaxial with the bore with a cross-sectional area smaller than the cross-sectional area of the valve bore. A poppet type valve member is slidable in the bore and has a reduced end portion engageable with the seat to shut off flow between the first and second fluid lines and a spring yieldably urges the valve member to a closed position.

Abstract: An apparatus is provided for controlling discharge of fuel vapor and liquid fuel through an aperture in a fuel tank. The apparatus comprises a housing mounted in the aperture and formed to include a venting outlet, and a blocking mechanism for blocking the flow of fuel vapor through the venting outlet. The apparatus also includes a mechanism for using pressurized fuel vapor from the fuel tank to move the blocking mechanism from a flow-blocking position to a flow-delivery position. The using mechanism includes a diaphragm appended to the blocking means for movement therewith. The apparatus further includes a second mechanism for using fuel vapor discharged from the fuel tank to provide a pressure cushion acting against the diaphragm to urge the diaphragm from its second position toward its first position.

Abstract: A bidirectional cartridge valve comprises a generally cylindrical valve housing including an end port and a side port each opening into an axial, cylindrical bore defining a valve chamber. A flow control element is movable in the valve chamber between a valve open position to open a flow path between the two ports and a valve closed position to block the flow path between the two ports. The flow control element includes a first passage provided with a first check valve connecting the end port with the valve chamber and a second passage with a second check valve connecting the side port with the valve chamber. A cylindrical pilot seat in the chamber includes a partial, axial bore defining a pilot chamber and an opening through the seat connecting the valve chamber with the pilot chamber. A third passage is provided through the valve housing, provided with a third check valve, connecting the pilot chamber to the side port.

Abstract: This invention relates to automatic transmissions and more particularly to valves for controlling and limiting automatic transmission breathing to reduce oxidation of the operating fluid fill. The valve permits relief of any residual pressure within the transmission housing for checking the operating fluid level.

Abstract: A bidirectional check valve that includes a housing having an internal cavity with fluid openings at axially opposed ends. A first valve element comprises a cup-shaped sleeve having a base adjacent to one axial end of the cavity and a sidewall axially slidably embraced by the housing within the cavity. A first fluid passage extends through the base of the sleeve adjacent to one of the cavity openings. A second valve element comprises a spool telescopically slidably received within the sidewall of the sleeve. A second fluid passage extends through the spool end from adjacent the second end of the housing cavity to internally adjacent the sidewall of the sleeve. A fluid passage is formed between the radially opposed surfaces of the sleeve and the spool for passing fluid therethrough as a function of axial position of the sleeve and spool with respect to each other.

Abstract: The invention refers to a pilot controlled pressure relief valve comprising a pair of fluid ports to be operable in both directions of flow. The pressure relief valve is provided with a single pilot control valve 24 which allows for an equal actuating pressure in both flow directions.

Abstract: A self-sealing valve is provided for fluid dispensing packages and the like, of the type which are compressed and decompressed to dispense therefrom liquids, pastes, powders and other similar flowable materials. The valve has a marginal groove extending along one face thereof in a closed pattern to define a central area inside the groove, and an outer area outside the groove. Ribs extend between the center and outer areas of the valve to bridge the groove, and selectively support the center valve area in a trampoline-like fashion. A slit extends through the center valve area, and into at least a portion of the groove to form an orifice that shifts between outwardly open, closed, and inwardly open positions in response to compressing and decompressing the container.

Abstract: A combination pressure/vacuum relief valve is formed by a closed end cylindrical body having a first port providing communication with a fluid containing vessel and a second port providing communication with the atmosphere. A piston valve within the cylinder is normally seated on a valve seat between the ports with the respective end portions of the piston rod projecting through the closed ends of the cylinder. Each end of the cylinder is provided with a cage supporting a pressure responsive fuse rod interposed between the outwardly projecting end of the piston rod and the opposite end of the cage. When the fluid pressure within the vessel falls below or exceeds a predetermined value, such pressure axially moves the piston valve in a respective unseating direction for providing communication between the interior of the fluid vessel with the atmosphere.

Abstract: A mud saver valve for automatically closing to prevent loss and spilling of drilling mud. The valve contains a diaphragm, rigid backup means and diaphragm support means so that the valve can be used in high pressure wells.

Abstract: A bi-directional vent for a fuel tank utilizes a resilient sealing member which in its unflexed state is a simple resilient washer. The sealing member is disposed inside a vent body, and forms both an inner and outer seal. The inner seal is formed between an inner circumferential edge on a central hole in the washer and a conical sealing surface attached to the vent body. The outer seal is formed between an outer annular sealing surface on the washer and a circumferential edge formed on a central opening in the vent body. Increased pressure in the tank causes the sealing member to deflect at its inner portion away from the circumferential edge on the vent body, resulting in outward venting. Reduced pressure in the tank causes the outer part of the sealing member to deflect away from the conical seating surface, resulting in inward venting.

Abstract: A two-way valve comprises a body containing two cylinders, a pair of valve assemblies, each comprising a piston which slides in a respective cylinder, each piston having a spindle extending from one end, a metering valve member which slides on the spindle and normally engages a valve seat at an end of the relevant cylinder, a circlip or other abutment on the spindle which engages the valve member and moves it away from the seat upon movement of the piston in one direction by hydraulic pressure, and a restraining spring inhibiting that movement.

Abstract: A valve device is disclosed for an aeration and air evacuation pipe leading away from a motor fuel tank. In a known valve device for aerating and evacuating air from a motor fuel tank, a positive pressure valve is provided, the closing force of which is generated by a compression spring which is braced against its valve element. This closing force generally corresponds to the positive pressure value of a water column of 300 to 400 mm. Such a positive pressure valve is therefore unsuitable for aeration and air evacuation devices in which the required positive pressure value is very low, only approximately 80 mm WG for example, for safety and functional considerations, and correct functioning of the valve element of the positive pressure valve is required to be ensured even at low temperatures.

Abstract: A mud valve assembly is disclosed having a valve member with a first sealing surface and a piston member with a second sealing surface which seals against the first sealing surface such that the piston and the first sealing surface move downward in response to pressure from above which exceeds a predetermined pressure level and the valve member and the second sealing surface move upward in response to pressure from below the valve assembly. The valve member with the second sealing surface can be retrieved from the bore of the drill pipe and reinstalled into the bore of the drill pipe without removing the mud valve assembly from the drill pipe.

Abstract: A fuel delivery system for automobile engine and like applications in which a canister is positioned within a fuel tank and has an open layer end and an internal wall spaced from the lower canister end for dividing the canister into upper and lower chambers. An electric fuel pump is carried by the canister wall within the upper chamber and has an inlet coupled through the wall to the lower chamber. The pump outlet feeds fuel under pressure to an engine, and excess fuel is returned to the upper chamber which thus forms a fuel reservoir. A valve is responsive to fuel level in the upper chamber for selectively feeding fuel from the upper reservoir chamber to the lower chamber, and then to the pump inlet, when fuel level in the upper chamber approaches maximum reservoir capacity.

Abstract: An improved wheel end valve assembly (11A) for a central tire inflation system (10) having a single connection (68) to a tire chamber (74) and a single supply connection (62) to a source ( 142) of pressurized fluid, which requires no venting other than through the single supply connection (62), is effective in response to pressurization and venting of the single supply connection (62) to open and close communication to the tire chamber (74), and which is not affected by ambient temperature changes nor susceptible to leakage into and out of a trapped air volume employed by prior art valve (11) disclosed herein. The valve (11A) is actuated by air pressure and is resiliently biased into closed position by a spring (342) positioned within an evacuated bellows (334).

Abstract: The present invention is a one-way fluid valve which consists of a shuttle chamber (29) with its two ends connected with the two fluid openings (22,22'), a shell (2) incorporating a by-pass (20) which is connected with the two ends of the shuttle chamber, a plunger (1) inserted in the shuttle chamber, and two throttling control elements (3,3') placed at the two ends of shuttle chamber used for controlling the stroke of the plunger. This kind of shuttle valve may be installed in a single pipe-line, the fluid may flow through it in forward and backward directions. It has the function of regulating the flow-rate of fluid forward and backward, hence is able to handle unequal flow-rates forward and backward. It can also function as one-way non-return valve, two-way alternating non-return valve and can be totally shut and fully opened.

Abstract: A valve which works without friction is provided which includes a movable obturating member and an annular seat. The annular seat is secured to a base by means of a support. The obturating member, preferably a ball, is set in a support which is fixed in the central opening of a substantially flat circular flexible membrane. The circular membrane is secured in a prestressed condition, in a plane parallel to the plane of the annular seat with the obturating ball member coaxial to the seat, by welding the contour of the membrane to the base. The membrane is mechanically isotropic so as to be radially rigid in the plane thereof and deformable in the direction perpendicular to its plane. Deformation of the circular membrane in directions perpendicular to its plane cause the obturating ball member to move into and away from the annular seat to interrupt and allow fluid flow therethrough.

Abstract: An improved compact pilot-assisted pressure relief valve is disclosed. The invention includes a vent piston or the like hydraulically dividing the valve body bore into a hydraulic fluid chamber and a spring chamber which is vented to atmosphere, such that backpressure is eliminated entirely for both faster reaction to pressure impulses and improved accuracy in pre-load setting of the valve assembly.

Abstract: An improved hydraulic circuit for automatically sequencing a pair of hydraulic cylinders through alternate extension and retraction cycles. A manually operated control valve initiates addition and withdrawal of fluid within the circuit and a logic valve determines which cylinder will be in communication with the control valve. The circuit uses an improved flow restrictor arrangement for creating the pressure drop which automatically shifts the logic valve. The restrictor consists of an orifice, a simple check valve and a constant pressure relief valve, all arranged in parallel. The functions of these various restrictor elements can all be performed by a single multifunction valve disclosed herein.

Abstract: A method for preventing the introduction of air into the vascular system of a patient during intravenous or intra-arterial procedures, as well as for preventing the reflux of fluids into the body of a patient. Also, novel fluid directing means and catheters which include integral or attached fluid flow control means for use in this method.

Abstract: A mud valve assembly with a valve means with a first sealing surface and a piston means with a second sealing surface which seals against the first sealing surface such that the piston and the first seal surface move downward in response to pressure from above which exceeds a predetermined pressure level and the valve means and the second sealing surface move upwards in response to pressure from below the valve assembly; and the valve means with the second sealing surface can be retrieved from the bore of the drill pipe and reinstalled into the bore of the drill pipe without removing the mud valve assembly from the drill pipe.

Abstract: A hydraulically damped motor mount comprises a bearing plate, annular resilient element and a bottom plate forming a working space which is connected through a choke opening to a liquid-filled equalization space of variable volume. A partition formed from a soft-elastic material is provided between the two spaces. The partition forms a seal at its circumference. The partition is provided with at least one cut which severs the partition substantially without removal of material. This cut provides a breakthrough for hydraulic liquid to flow through the partition between the working space and the equalization space when a selected value of hydraulic pressure is exceeded.

Abstract: A dual directional relief valve including a chamber within which is mounted a piston or valve member. The valve member is biased into a closed position covering and closing the open ends of two conduits. In the preferred embodiment, the conduits are respectively connected to opposite sides of a pump and the open ends of the conduits are concentrically positioned relative to each other. In operation and should dangerously high pressure develop on either side of the pump, the valve member will be opened and the high pressure relieved to pass harmlessly from one conduit to the other through the chamber. The valve member preferably has two surface portions of equal area covering the open ends of the conduits wherein the relief valve can be set to open when a predetermined pressure is exceeded in either conduit.