Abstract: The invention relates to a blade-type check valve for gaseous and liquid media, to be used in medical technologies as well as in waste water technology with at least three triangular blades, grouped in round configuration at the edges of a polygonal bore of a valve ring or housing, with the number of blades corresponding to the number of faces of the bore. At least at one of the three sides, the valve blades feature an integrated joint, which may also consist of fabric, whereas the two other sides of the valve blades form an articulated lock. The valve can be installed in any position and closes automatically, actuated by the backflow respectively return flow of the medium, without external energy.

Abstract: A chest valve including: a housing including an inlet configured to connect to a chest tube, an outlet and a fluid passage from the inlet to the outlet; and a one-way valve within the housing and included in the flow passage, wherein the one-way valve includes: (i) a first tubular strip wherein having an internal air passage and a first layer defining the air passage, wherein the first layer has a first thickness and the internal air passage of the first tubular strip is included in fluid passage of the housing; and (ii) a second tubular strip wherein having a second layer with a second thickness with a second thickness greater than the first thickness, wherein an outer surface of the second tubular strip is adjacent and overlaps an outer surface of the first tubular strip.

Abstract: An anti-free-flow valve includes a tube and a membrane. The tube extends from a first end of the tube to a second end of the tube. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane is spaced apart from the first and second ends of the tube. The membrane defines a slit therethrough that is configured to transition from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit responsive to compression or expansion of the tube proximate to the membrane.

Abstract: A therapeutic vaporizer inhalation bag attachment system with an integrated valve includes a body having a lumen extending between the two openings of the body, a bag coupling, and a valve positioned within the lumen. A first end of the body may include a mouthpiece and the second end of the body may include bag coupling to attach an inhalation bag. The body may include a plurality of cooling ribs extending in parallel with the lumen along an outer surface of a sidewall of the body.

Abstract: A crossover prevention valve for use in a multi-component fluid mixing and dispensing system includes a valve body defining at least two fluid passageways having respective one-way check valves at their outlet ends. A forward end of the valve body cooperates with an interior surface of a dispensing nozzle to define a mixing chamber for chemically reactive fluids prior to discharging the mixed fluids out of the dispensing nozzle. The crossover prevention valve does not permit reverse flow, thereby preventing clogs due to undesired intrusion of one reactant into the flow path of another reactant. Solidified reactants left in the mixing chamber are easily removed from the valve body, permitting the valve body to be reused even after sitting for extended periods.

Abstract: A duckbill valve assembly includes a duckbill valve and a spring member. The duckbill valve has a longitudinal axis, a lateral axis transverse to the longitudinal axis, and opposed proximal and distal ends spaced apart along the longitudinal axis. The duckbill valve defines a valve direction extending from the proximal end to the distal end. The duckbill valve includes a first port at the proximal end, and first and second opposed sidewalls. The first and second sidewalls taper inwardly toward one another in the valve direction to form a duckbill structure. The duckbill structure includes a slit proximate the distal end. The duckbill valve is transitionable from a closed position, wherein the slit is closed, and an open position, wherein the first and second sidewalls are laterally separated proximate the slit to form a second port. The spring member includes a spring leg disposed laterally adjacent the first side wall.

Abstract: An introducer sheath is disclosed having a high centering performance that is relatively easily capable of introducing an elongated body such as a catheter into an appropriate position, and is capable of appropriately maintaining hemostasis and insertibility of a valve body. The introducer sheath includes a tubular member provided with a hollow section through which an elongated body is freely insertable, a hub that includes an inner space which communicates with the hollow section of the tubular member and is provided on a proximal side of the tubular member, a valve body that is placed in the inner space of the hub, and an annular member that contacts with the valve body to fix the valve body to the inner space and includes a through-hole into which the elongated body can be inserted.

Abstract: A fluid check valve incorporating a temporary elastomeric functional barrier membrane, the check valve having a sealing member comprising a first elastomer and a barrier membrane comprising a second elastomer, different from the first elastomer, disposed directly upon the surface of the sealing member so as to form a continuous layer over at least a seal opening of the sealing member. The barrier membrane may include a photoinitiator and coagent which aids in the ultraviolet (UV) curing of the second elastomer after application upon the first. The barrier membrane may applied as a solution of monomers, photoinitiator, and optional coagent, the solvent evaporated, and the deposited solutes exposed to ultraviolet so as to form the barrier membrane material.

Abstract: A splittable sheath includes a splittable sheath body, a splittable sheath hub, and a valve element. The sheath body comprises a generally flexible tubular structure, a proximal end, and a distal end. The sheath body defines a longitudinal axis and is splittable into two halves along a pre-determined line generally parallel to the longitudinal axis. The sheath hub extends from the proximal end of the sheath body and defines a longitudinal axis generally aligned with the longitudinal axis of the sheath body. The sheath body and sheath hub form an inner cavity along their respective longitudinal axes. The valve element includes a resilient plate and a sealing element. The resilient plate includes a distal portion extending radially inwardly from a side of the inner cavity.

Abstract: A beverage bottle for storing and dispensing water and impure sports beverages having a container and a dispensing opening on a top wall movable between an open position and a closed position and a unitary valve disposed within the container bottom wall having a vertically sinuous contour, and laterally opposed, laterally actuating, compliant slit faces and a substantially rigid annular flat surface. As the vertically sinuous contour is flattened upon the annular flat surface, the slit faces are laterally urged together establishing a preloaded seal, for leak resistant valve operation, and reduced restriction dispensing of water and impure sports beverages.

Abstract: A system for controlling slurry flow through a flexible-walled transport tube. An example system includes a frame, a pivot pin, a rotatable radial arm having an attached pressure pad, a spring tension adjustment rod extending between the radial arm and the frame, and a coil spring concentric with the spring tension adjustment rod and configured to oppose rotation of the radial arm away from a flexible-walled transport tube contacting the pressure pad. In one operating condition, a decrease in the pressure of the slurry within the transport tube reduces the force applied by the slurry outward on the tube wall, leading the spring to rotate the radial arm toward the tube, causing the contact pad to deflect the wall of the flexible-walled transport tube and impeding the flow of slurry through the tube.

Abstract: A valve formed from a frustoconical piece of foldable material, having folds extending from a closable end towards the other end that connects to a container of liquid, each fold having an inner crease extending into the interior region of the nozzle. The valve has a biasing mechanism that may include a spiral spring encircling a nozzle to bias the inner creases inward to cause them to abut each other at the closable end so that the valve is maintained in a closed position. When liquid is forced into the interior region under sufficient pressure it causes the nozzle to move from the closed position to an open position so liquid flows from the interior region out the closable end of the nozzle, and when the pressure on the liquid is removed, the biasing mechanism causes the nozzle to move back to the closed position.

Abstract: A hollow tubular element is inserted in the descending aorta. The caudad end contains a pressure sensitive passive or preferably, hydraulically or electrically activated, unidirectional valve. A flexible diaphragm situated in a rigid shell affixed over an opening in the element wall divides the shell interior into first and second variable volume chambers. The first chamber opens to the artery. A continuously operating electrical pump is connected to the second chamber through a closed hydraulic system including a multi-valve chamber. The valves regulate fluid flow to the second chamber in accordance with electrical signals from the heart. Fluid flow is directed to the second chamber during cardiac diastole and away from the second chamber during cardiac systole, causing the device to function in a counterpulsation mode. The work of the heart is decreased and coronary blood flow is increased to promote the formation of new coronary collateral channels and the perfusion of the heart itself.

Abstract: A check valve is provided comprising a conduit for conveying a fluid, the conduit having an inlet and an outlet, the conduit having a first region adjacent the outlet (13) comprising a flexible wall, two opposing sides of the flexible wall converging towards each other to form a closed geometry when the pressure of the fluid upstream of the inlet and the pressure of the fluid downstream of the outlet are substantially equal, the closed geometry comprising each of the opposing sides (23, 24) being arcuate in cross-section and lying against each other in a substantially sealing relationship (21, 22). Preferably, two connecting regions of the wall connecting the two opposing sides (15, 16) are biased towards each other by a biasing means. Preferably, the biasing means comprises one or more flexible ring members (25) encircling the flexible wall attached at points (25A and 25B). Preferably, the conduit takes the form of a duck beak valve (20). The figure shows an end view onto the check valve outlet.

Abstract: A flow control device includes a fitting having three portals. One of the portals is an entry portal for a liquid, one of the portals is an entry portal for a gas, and the other portal is an exit portal for either the liquid or the gas. A normally closed back flow prevention valve is located in fitting. The back flow prevention valve prevents back flow of liquid through the fitting. The fitting and the backflow prevention valve also minimize or eliminate the formation of air bubbles in the liquid.

Abstract: A one-piece container closure with a collar, stiff planar triangular leaflets attached by linear hinges to the collar, and thin flexible foldable webs attached to and extending between the leaflets. The leaflets are flat with the webs folded beneath in closed closure position. The leaflets are pivoted upwardly with webs unfolded therebetween in open position. An integral cap is attached to the collar by a snap-action bow-tie hinge. A central pin on the cap seals with the leaflets when the cap is closed. The closure is integrally molded in open position with raised leaflets and unfolded webs, leaflets then being lowered and the webs folded to closed position while the closure is still warm, the cap then being closed, and the closed closure then being annealed to establish the elastic positional memory of the leaflets and hinges in the closed position when product is not being dispensed through the closure.

Abstract: A one-piece container closure with a collar, leaflets hingedly attached to the collar, and thin flexible foldable webs attached to and extending between the leaflets. The leaflets are flat with the webs folded beneath in closed closure position. The leaflets are pivoted upwardly with webs unfolded therebetween in open position. An integral cap is attached to the collar by a snap-action bow-tie hinge. A central pin on the cap seals with the leaflets when the cap is closed. The closure is integrally molded in open position with raised leaflets and unfolded webs, leaflets then being lowered and the webs folded to closed position while the closure is still warm.

Abstract: A flapper finger valve assembly for use in an exhaust system. The flapper finger valve includes a tube having a plurality of orifices therethrough. The flapper finger valve assembly also includes a plurality of flapper finger valves generally having a C-shape wherein the flapper finger valves are arranged on an outside surface of the tube. The flapper finger valves are capable of radial movement with respect to the tube. A plurality of retainers generally having a C-shape are arranged around the flapper finger valve. These retainers will define a maximum radial movement for such flapper finger valves on the tube. The flapper finger valve assembly also includes a fastener which will secure the flapper finger valves between a tube and retainers in the flapper finger valve assembly.

Abstract: A check valve includes two opposing sheets surfaces that are coupled together to form a flow channel there between. The flow channel has a first end, a second end and at least one direction-changing portion in between the first and second ends. A first opening is provided at the first end of the flow channel and a second opening is provided at the second end of the flow channel.

Abstract: A flapper finger valve assembly for use in an exhaust system. The flapper finger valve includes a tube having a plurality of orifices therethrough. The flapper finger valve assembly also includes a plurality of flapper finger valves generally having a C-shape wherein the flapper finger valves are arranged on an outside surface of the tube. The flapper finger valves are capable of radial movement with respect to the tube. A plurality of retainers generally having a C-shape are arranged around the flapper finger valve. These retainers will define a maximum radial movement for such flapper finger valves on the tube. The flapper finger valve assembly also includes a fastener which will secure the flapper finger valves between a tube and retainers in the flapper finger valve assembly.

Abstract: A method and apparatus for admitting liquid from a draining surface into a drain conduit and for preventing discharge of waste gas from the drain conduit into the atmosphere in response to a higher pressure in the drain conduit than at the draining surface. The method and apparatus typically are for use draining floors, basements, roofs, countertops, exterior paved areas, and surfaces draining into line that could discharge waste gas back into the environment. The invention provides floor drain assemblies and check valves with good drainage performance with out the use of P or U-traps, and is particularly well suited for use when drainage occurs irregularly. Floor drains according to the invention comprise check valves adapted for disposition within floor drains, the check valves generally comprising spring-loaded stops, elastic diaphragms, or sheath valves. Check valves according to the invention are preferably installable in existing drain structures, and are easily removable.

Abstract: A carburetor for a small internal combustion engine has a manual priming fuel pump with a resilient valve for allowing fuel flow in a first direction and for preventing fuel flow in a second direction. The resilient valve is reinforced with longitudinally extending ribs to prevent recirculation of fuel through an outlet orifice of the valve in a running engine. The outlet orifice is defined by a distal end of a tubular portion of the valve press fitted and projecting into an outlet passage that communicates with a pump chamber defined by a resilient domed cap. The ribs project laterally outward from the tubular portion within the outlet passage. Integral with an opposite end of the resilient valve is a head which flexes outward to open an inlet passage which then communicates with the pump chamber.

Abstract: A check valve having an upstream inlet part mountable on a discharge end of a conduit, a downstream outlet part adapted to prevent backflow of fluid through the check valve, and a transition part located between the upstream inlet part and the downstream outlet part. A longitudinal dimension of the downstream outlet part extending in a direction transverse to a direction of flow is at least approximately 1.57 times the diameter of the upstream inlet part.

Abstract: A duckbill valve is provided which includes a hollow cylindrical elastomeric body with first and second ends. The first end has walls parabolically tapering to an elongate slit, the slit being surrounded by an upper and lower lip. The second end has a non-uniformly round (e.g. oval) outer wall terminating in an open mouth. When inserted into a perfectly round apertured fitting, the non-uniformly round outer walled elastomeric body is bowed to form-fit the round configuration thereby forcing shut the lips and slit. Upon increased air pressure within the elastomeric body, the slit is forced open. In a second embodiment, the inner wall of the second end may be non-uniformly (e.g. oval) round. Insertion of a round tubular fitting within the non-round inner wall of the elastomeric body also achieves a bowed form-fit configuration which forces shut the lips and slit.

Abstract: A cannula includes a cannula cap connected to a proximal end of the cannula, which cap has cap body having a bore defining an instrument receiving passageway. A monolithic flapper valve is positioned within the cannula proximal end and adjacent the cap body. The flapper valve includes a flapper, a flapper mount positioned adjacent the cap body, and an integrally formed hinge connecting the flapper mount to the flapper for permitting the flapper to move to an open position when an instrument is positioned within the instrument receiving passageway and for biasing the flapper toward a closed position when the instrument is removed from the passageway. A sealing washer is carried by the flapper mount for positioning between the valve and the cannula cap enclosing the flapper valve within the cannula.

Abstract: The track roller bearing with stud according to the present invention is to provide a track roller bearing with stud that has a low production cost and offers easy handling in which lubrication work can be performed from either end surface of the stud and can be easily attached and removed from a machine tool and so forth. Lubricant supply port 21m continuing from the above hexagonal hole 21j is formed in addition to lubricant supply port 21n on the side of threaded portion 21e of stud 21 for the lubricant supply ports connected to lubricating paths 21g and 21h for supplying lubricant to rolling elements 24 and so forth, and lubricant supply plugs 31 are disposed in these lubricant supply ports.

Abstract: An asymmetrical check valve has an inlet end, a transition part and an outlet end, with a pair of vertical lips facing one another. The lips may be flat or they may be curvilinear. The check valve is asymmetric about a horizontal longitudinal plane through the check valve. The bottoms of the transition part and outlet end may be aligned, with a major portion of the lips extending above the horizontal plane. It is thus possible to install conventional or wide bill check valves in installations with little or no clearance between the outlet end and ground level.

Abstract: A valve assembly for permitting fluid flow in a first direction and for preventing fluid flow in a second direction opposite to the first direction. The valve assembly includes an upper housing, a lower housing coupled to the upper housing to form a generally axially extending housing assembly, and a valve seating section defined within an inner peripheral portion of the lower housing. The valve seating section includes an axially extending inner peripheral surface and a transversely extending surface substantially normal to the axially extending inner peripheral surface. A valve member is seated within the valve seating section of said lower housing. The valve member includes a flange that extends from the valve member in a transverse direction and defines an axially oriented outer peripheral surface thereof.

Abstract: A water bag type brassiere mounted in one cup of a brassiere and having a valve partially projecting to the outside through which the volume of contained fluid in the padding can be adjusted with a syringe, the valve including a rubber valve body and a rubber binding sleeve sleeved onto the rubber valve body, the valve body having longitudinal center hole at its heat outside the padding, and a split forced to close by the binding sleeve, the split being opened to let fluid pass when a needle of a syringe is inserted into the longitudinal center hole of the valve body.

Abstract: A cannula cap embodiment includes a monolithic elastomeric cap body having a sidewall portion for engaging a proximal end of a cannula, and an end portion connected to the cylindrical sidewall portion. The cannula cap also includes a monolithic flapper valve positioned within an interior of the cap body. The monolithic flapper valve includes a flapper portion, a ringed-shaped flapper mounting portion connected to adjacent interior portions of the cap body, and an integrally formed hinge portion connecting the flapper mounting portion to the flapper portion for permitting the flapper portion to move to an open position when an instrument is positioned within the instrument receiving passageway, and for biasing the flapper portion toward a closed position when an instrument is removed from the instrument receiving passageway.

Abstract: An inversion-resistant check valve or tide gate valve has a sleeve bounding a longitudinally extending, flow-through passage for fluids. The sleeve has an intermediate region and an upstream fluid inlet end region mountable on a discharge end of a conduit which is elongated along a longitudinal first axis of symmetry. The sleeve also has a downstream fluid outlet end region comprised of two or more thin and flexible lips which are opposed to each other and which are pre-formed to define a bill which is curvilinear. The lips are thinner and more flexible than the intermediate region. The curvilinear bill ensures sealing of the thinner, more flexible lips, allows easier opening of the valve, and reduces the likelihood of gapping in the lips. Unwanted backflow through the check valve is thereby prevented.

Abstract: An improved non-drip nozzle valve which can be retro-fitted onto existing fuel dispensing nozzles comprises an expanding integral wire frame made from two spaced, interconnected C-shaped springs. Once inserted into the throat of the fuel dispensing nozzle, the C-shaped springs expand the frame to engage the inner wall of the nozzle. Each C-shaped portion of the frame is provided with a rubber flap valve half. The two halves of the flap valve overlap each other when the fuel flow is discontinued to prevent any remaining fuel from dripping or spilling out of the end of the nozzle. When the fuel is being pumped, the flow pressure is great enough to unseat the flap valve halves allowing fuel to freely flow past the valve.

Abstract: An inversion-resistant check valve or tide gate valve which comprises a sleeve bounding in a longitudinally-extending flow-through passage for fluids. The sleeve has an upstream fluid inlet end region mountable on a discharge end of a conduit which is elongated along a longitudinal axis of symmetry. The sleeve also has a downstream fluid outlet end region comprised of two or more lips which are opposed to each other and symmetrically arranged relative to the axis, wherein the lips extend a defined length along the axis, the defined length being within the range of about 1:1.5 to 1:9 times the diameter of the conduit.

Abstract: A valve for permitting fluid flow in a first desired direction and preventing fluid flow in a reverse direction. The valve includes a valve body having a rigid wall defining inlet and outlet openings at opposite ends thereof and a main flow passageway between the inlet and outlet openings. Secured to the rigid wall, so as to receive fluid entering the passageway through the inlet opening, is a tubular valve member of elastomeric material having upstream and downstream ends in fluid communication with one another. The tubular valve member is normally open to fluid flow but is yieldingly collapsible in response to downstream pressure increases to prevent fluid from passing therethrough. A ring is secured about the tubular valve member and is dimensioned to prevent the passage of the downstream end through the inlet opening in the event of a downstream pressure increase. The drain control valve may be employed in conjunction with a novel manifold for irrigation purposes.

Abstract: A cannula having an elongate rigid tubular member with proximal and distal extremities. A cylindrical housing is secured to the proximal extremity of the tubular member. A duckbill valve assembly is disposed in the cylindrical housing. The valve assembly has a valve member formed of an elastomeric material and having first and second leaflets forming a duckbill-type seal. First and second spring fingers are provided which engage said first and second leaflets and yieldably urge the leaflets into a closed position whereby in the event the leaflets take a permanent set towards an open position, the spring fingers will urge the first and second leaflets into a closed sealing position.

Abstract: A method of making a pressure relief valve includes embedding a pair of opposed plates within a pair of valve lips, forming holes in the lips, inserting springs into the holes into engagement with the plates, and tensioning the springs to constantly urge the lips toward each other.

Abstract: A pressure relief valve has coil springs embedded within valve lips for constantly urging the lips closed. The internal springs resist environmental corrosion, and eliminate multi-part complex valve actuators.

Abstract: The present invention relates to a duckbill conservation vent valve comprising an elastomeric tubular body having an axial fluid passageway with an inlet and an outlet. The tubular body progressively narrows in cross section from inlet to outlet, forming opposed sealing lips at the outlet. The lips define a closed slit therebetween. The slit is opened in response to pressure exerted from the inlet in the direction of the slit. The slit is kept closed by means such as applying either external or internal force on opposing ribs which extend radially from the tubular body or by draping a long lip over a slit and a short lip, or by stretching a short lip to equal the length of a long lip and attaching the short lip to the long lip. The duckbill conservation vent valve is capable of being opened by pressure heads of less than about 2 inches of water.

Abstract: A gas flow valve enables constant venting and is used with a cuff showing a rapid decrease in venting ability at a predetermined value on a boundary within the pressure range which allows measurment of blood pressure. The gas flow valve has a body made of an elastic material and comprising a wedge-shaped portion formed integrally with a mounting base so as to have a flat portion with upper and lower surfaces serving as pressure-responsive surfaces, a linear opening formed at the tip of the wedge-shaped portion, and a passageway communicating with the opening and extending in the longitudinal direction within the mounting base and the tip portion. A thin sheet-like member is twisted and disposed in the passageway so that the tip portion is held by the opening. As a result, the elastic deformation of the gas passageway formed by the gaps in the opening during pressure reduction is promoted by the resiliency of the torsion of the thin sheet-like member.

Abstract: The present invention provides a valve assembly for allowing fluid flow in a first direction and for preventing fluid flow in a second, opposite direction including a valve housing having first and second ports opening into the housing. A flow regulator is positioned within the housing and includes an outer wall which is formed as a substantially cylindrical member. The regulator includes a pair of semi-circular valve lips which are oriented in converging relationship to each other to form an outlet slit at one end of the regulator. The valve lips are connected to the outer wall by a pair of concave connecting walls wherein the lips and connecting walls form a pair of cavities on either side of the outlet slit. A pair of elongated projections are located along diametrically opposing sides of the outer wall for biasing the outer wall inwardly whereby a biasing force is applied to close the lips.

Abstract: An exhaust gas aftertreatment system having an air supply system is disclosed and includes an air feeding pump for selectively creating a flow of air through a flow passage which directs the flow of air to a regeneration system. A check valve is provided including a valve element having a circular base portion surrounding and supported by the flow passage, a flexing portion extending from the circular base portion and converging to form a diametrically extending tip, and a diametrical slit formed in the tip. Also, a support structure is positioned to extend into the valve element to a position adjacent the tip for supporting the flexing portion such that the valve element permits the flow of air from the air feeding pump in one direction and prevents the flow of exhaust gas in an opposite direction with the support structure preventing the valve element from collapsing when the air feeding pump is inoperable.

Abstract: A non-return valve for bore hole sleeves, which are intended for injection of a sealing and/or reinforcing compound into rock cracks and similar cracks and which comprise a rigid case (10), one end (10A) of which is provided with means for detachable connection to the case of a pump hose (12) for the compound to be injected, as well as an expandable device (15) for securing the rigid case in the bore hole (21), comprises an elastic sleeve (22) which is adapted at the other end (10B) of the rigid case (10) in such a way that the rigid case (10) runs into the elastic sleeve (22). The elastic sleeve is adapted for automatical contraction, when no compound is being injected through the elastic sleeve, so that already injected compound can not flow backwards into the rigid case (10). The sleeve (22) is preferably provided with diametrically positioned clamp means (23-26) at its free ends, so that the free end of the sleeve has a flat shape, when no compound is being injected through the elastic sleeve.

Abstract: A one-piece, resilient nozzle on an outlet pipe of a carton filler includes two relatively rigid flaps at opposite sides of the nozzle and two relatively flexible walls at other opposite sides of the nozzle, to form with the flaps a loop encircling the nozzle interior. The flaps are biassed, by the inherent resilience of the nozzle, about an axis perpendicular to the nozzle and parallel to linear bottom edges of the flaps into a closed position wherein those edges come together along a linear zone at the base of a downwardly converging interior space bounded by the loop.

Abstract: A tide gate valve has staggered pads embedded therein to provide sufficient strength to resist sagging and inversion, and to provide sufficient flexibility to promote an easy opening of the valve.

Abstract: An inversion-resistant tide gate valve includes a multiple-ply sleeve, and a rigid support member embedded therein to prevent the sleeve from sagging and to impart strength to the sleeve to prevent inversion.

Abstract: A normally closed duckbill valve for controlling the direction of fluid flow in a fluid-conducting conduit and a method of manufacturing the valve are provided. The valve is formed of elastomeric material and comprises a generally cylindrical body member provided with an axial fluid passageway having an inlet end and an outlet end provided with an outlet slit, and progressively narrowing in cross-section from the inlet end to the outlet end to define a pair of opposed sealing lips at the outlet slit. Means for normally urging the sealing lips into a closed position are provided and comprise widened lip margins disposed at opposite ends of the outlet slit. The valve is formed by molding the elastomeric material into the preferred shape and then providing the widened lip margins with a closing bias by causing a greater amount of shrinkage in the lip margins, relative to the remaining portions of the sealing lips, during curing of the molded material from an elevated curing temperature to room temperature.

Abstract: A check valve for controlling the flow of fluid through a pipe or other means defining a passageway. The valve comprises an elastomeric valve element that permits flow of fluid through the passageway in a downstream direction while preventing the flow of fluid in the upstream direction. The valve element has a base that is secured to the means defining the passageway, there being an opening in the base through which fluid can flow. Flow of fluid is controlled by vanes projecting downstream from the base, each vane being flexibly connected to the base and being movable about its line of connection with the base between an open position in which the vanes permit ready flow of fluid in a forward direction, and a closed position in which the vanes make sealing engagement with each other, thus preventing upstream flow of fluid.

Abstract: A bi-directional pressure relief valve includes a cylindrical main body portion defining a flow path through the valve and terminating in an asymmetrical lip portion having a curved contour about an axis of curvature extending perpendicularly to the flow path and a linear contour which is substantially normal to the curved contour. The lip portion has a normally closed slit formed through it and expands to open the slit to permit flow in one direction in response to pressure differentials across the lip portion above a first pressure differential, regains its undeformed shape to close the slit and check flow at pressure differentials below the first differential and above a second pressure differential, and collapses in a predictable and repeatable manner to open the slit to permit flow in an opposite direction at pressure differentials below the second pressure differential.

Abstract: A combination check-overpressure relief valve includes a cylindrical main body portion defining a flow path through the valve and terminating in a curved lip portion having a radius of curvature extending perpendicularly to the flow path. The curved lip portion has a normally closed slit formed through it which opens to flow in one direction but checks flow in an opposite direction until a certain pressure is exceeded, at which the valve relieves to allow flow in the opposite direction. The valve will thereafter automatically reset to its original checking position once the pressure has dropped sufficiently. If desired the pressures at which flow can occur through the valve may be increased by providing the valve with stiffening ribs projecting radially outwardly of the main body portion.

Abstract: An improved valve prosthesis for causing nontraumatic unidirectional flow of a pulsatory fluid, such as blood, through a conduit, such as a blood vessel. The valve includes two flaps, made of a suitable flexible material, attached by the proximal ends to opposite sides of a covered annular mounting structure. A pair of magnetic members are connected to the distal ends of the flaps thereby to exert sufficient attractive force to hold the flaps together in a closed position to prevent fluid flow through the valve. The magnetically-closed flaps are forced to an open position by the pressure of the fluid flowing through the conduit. A decrease in fluid pressure in combination with the attractive force exerted by the magnetic members permits the smooth, nontraumatic closure of the valve flaps.