Abstract: A flow control valve, comprising a flow controlling valve configured to deflect from a generally planar posture to an increasingly nonplanar posture responsive to a relative increase in pressure difference and flow across the valve element; and a support element including a support structure supporting the valve element in its undeflected state; at least a first contact surface recessed from the support structure and configured to engage the valve element only when the valve element is deflected; and a flow passage wherein an effective flow-through volume through the at least one opening and the flow passage decreases as deflection of the valve element increases.

Abstract: A vehicle air-conditioning system includes an air-conditioner and an air outlet for opening and closing an opening formed in a rear part of a vehicle body. A control unit causes the air outlet to open and close the opening in accordance with changes in air conditions in a passenger compartment, so as to keep the passenger compartment environmentally good condition.

Abstract: A check valve and method for manufacture of the check valve. The check valve comprises a substrate and a channel in the substrate. The channel has an anchor region, a channel corridor and a valve seat region. There is an elastomeric valve mechanism in the channel. The valve mechanism has an anchor portion anchored in the anchor region, an elastomeric web portion in the channel corridor and a valve plug in the valve seat region. The elastomeric web portion interconnects the anchor portion and the valve plug. The elastomeric web portion is in a stretched state such that the valve plug is forced by the elastomeric web portion against the valve seat region to seal the valve seat region. The force of the elastomeric web portion can be overcome by operative fluid pressure within the channel to separate the valve plug from the valve seat region and thereby open the channel at the valve seat region to allow the fluid to exit the channel via the valve seat region.

Abstract: A compressor includes a casing, a driving part adapted to be accommodated in the casing for generating a driving force, a compression part for compressing gas with the driving force from the driving part and provided with an inlet for inhaling the gas and an outlet for discharging the compressed gas, and a valve apparatus for opening and closing the outlet. The valve apparatus has a valve body accommodation part including an inner surface of a cylindrical shape for communicating with the outlet, and connected to a gas discharging path for discharging the compressed gas discharged through the outlet; and a valve body accommodated in the valve body accommodation part and curved to close the outlet elastically and to open the outlet with the compressed gas of the compression part.

Abstract: An umbrella valve includes an umbrella-valve body having a stem, a flexible umbrella, and a flange. The umbrella and the flange are each attached to, and extend radially outward from, the stem. The flange has at least one fluid passage. The umbrella valve can be placed in a valve housing having a sealing-surface portion. The umbrella, when the umbrella-valve body is placed in the valve housing, is pushed away from the sealing-surface portion under a forward fluid flow and is pushed against the sealing-surface portion under a reverse fluid flow. An umbrella-valve assembly includes the umbrella valve and the valve housing.

Abstract: A pressure relief valve (12) for relieving air pressure from a passenger compartment (14) of a vehicle (10) includes a base (18) having a peripheral portion (30). A central opening (42) extends through the peripheral portion (30). The pressure relief valve (12) also includes a plurality of flaps (74) for closing the central opening (42) of the base (18). Each flap (74) has an outer end (82) connected with the peripheral portion (30) of the base (18) and an inner end (80) that is movable relative to the peripheral portion (30) and the other flaps (74) for enabling airflow through the central opening (42). Each flap (74) has opposite surfaces (76 and 78) against which air pressure acts. Differential air pressure acts on the opposite surfaces (76 and 78) causing the flap (74) to move to enable airflow through the central opening (42).

Abstract: A micropump check valve device which can be designed thin with good assemblability and applied with urging force. The micropump check valve device includes an upstream side member having a small-bore hole for passing therethrough a fluid, a downstream side member having a large-bore hole for passing therethrough the fluid, and a valve member having a valve mechanism sandwiched between the upstream side member and the downstream side member. The valve mechanism includes a passing hole formed in correspondence to a position and a size of the large-bore hole in the downstream side member, a contacting part formed inside the passing hole in correspondence to the position and size of the small-bore hole in the upstream side member thereby to close the small-bore hole, and supporting parts formed to bridge across the passing hole to support the contacting part. The valve member has a greater linear expansion coefficient than the upstream side and downstream side members.

Abstract: A membrane valve wherein the shutter disk is retained in contact with the valve seat during ejection of liquid or gas by means of one or more ribs that are substantially in contact with the shutter disk along one or more lines secant to the shutter disk and/or by means of one or more rows of secondary clamping pins that are engaged in matching openings on the valve seat. Further, a second stage pressure reducer for two-stage underwater regulators incorporating a membrane valve wherein the shutter disk is retained in contact with the valve seat during exhalation of gas by means of one or more ribs that are substantially in contact with the shutter disk along one or more lines secant to the shutter disk and/or by means of one or more rows of secondary clamping pins that are engaged in matching openings on the valve seat.

Abstract: A yard hydrant having a valve body with a valve seat and a drain port. A closure valve disposed within the valve body and engaging the valve seat. The valve body having a conduit in fluid communication with the drain port and a hollow interior of the valve body. A check valve disposed within the conduit to prevent fluid flow from the drain port through the conduit to the hollow interior.

Abstract: A pressure relief valve that is mountable to protect packaging so as to vent pressurized gases contained within the packaging. The present invention also pertains to a pressure relief valve which includes at least one passageway defined by at least one inner rail and which is in communication with an aperture.

Abstract: A pressure control valve for a packaging container includes a supporting body having a recess a is disposed in an axially captive fashion either by means of gluing or by means of securing projections A device for attaching the pressure control valve to a material web has a stroke die and a sealing die that cooperates with the stroke die and contains a needle holder for producing holes in the material web.

Abstract: Ink maintained at a negative pressure state is supplied to an ink-jet recording head via an ink supply mechanism constructed as a differential pressure valve having a coil spring 51 and a movable membrane 54 normally contacted elastically with a valve seat by the coil spring 51.

Abstract: A fuel system and a method of method of managing fuel vapor pressure in the fuel system. The fuel system a fuel tank having a headspace, a fuel vapor collection canister in fluid communication with the headspace, a purge valve, and a fuel vapor pressure management apparatus. The method includes performing leak detection on the headspace, and preventing a flow of fluid through an elastic diaphragm during leak detection. The elastic diaphragm includes at least one opening through which passes the flow of fluid. And the preventing the flow of fluid includes a first portion of the elastic diaphragm sealingly engaging a second portion of the elastic diaphragm. The method further includes relieving excess negative pressure in the headspace and relieving excess positive pressure in the headspace by fluid flow in different directions along the same flow path that includes the opening in the diaphragm.

Abstract: A fuel vapor pressure management apparatus for a fuel system performs leak detection on a headspace of the fuel system, performs excess negative pressure relief of the headspace, and performs excess positive pressure relief of the headspace. The fuel vapor pressure management apparatus includes a diaphragm that is deformable between a nearly undeformed configuration that is associated with performing leak detection, a first deformed configuration that is associated with performing excess negative pressure relief, and a second deformed configuration that is associated with performing excess positive pressure relief. A first fluid flow through the diaphragm occurs when the diaphragm is in the first deformed configuration. A second fluid flow through the diaphragm occurs when the diaphragm is in the second deformed configuration, and the second fluid flow is opposite to the first fluid flow.

Abstract: A pressure relief valve (10) includes a housing (20) defining an air flow passage (34). A flap (90) overlies the air flow passage (34). At least a portion (92, 94) of the flap (90) is movable, in response to an air pressure differential acting on opposite portions of the flap, between an open condition venting air from one side (18) of the valve (10) to a closed condition blocking flow of air from a second side (19) of the valve. The flap (90) has a plurality of mounting openings (104, 106). The housing (20) has a plurality of generally T-shaped mounting posts (70, 72) projecting from the housing. A snap connection is provided between the flap (90) and the mounting posts (70, 72) to secure the flap to the housing (20) with the mounting posts extending through the openings (104, 106). The mounting posts (70, 72) are the only structure holding the flap (90) on the housing (20).

Abstract: A one-way fluid valve member (10) to be mounted on a valve (12) body having a valve opening (18) surrounded by a valve seat (16). The valve member (10) includes,: a valve closure part (14) to be movably mounted on the body (12) for movement relative thereto between a first position engaging the seat (16) to prevent movement of fluid through the opening (18) in a predetermined direction, and a second position spaced from the seat (16) to allow fluid to pass through the opening (18) in a direction opposite the predetermined direction; and wherein the valve closure part (14) has a convex surface to engage the seat (16) so as to project into the opening (18).

Abstract: There is disclosed a fluid supply valve comprising a disc-shaped valve body which is equipped with a fluid supply port in the central portion thereof and composed of an elastic material whose peripheral portion is reinforced and fixed with a rigid material, the fluid supply port being closed when the valve body abuts against a fixed valve seat placed so as to be opposite to the fluid supply port, and being opened when the valve body is separated from the fixed valve seat, wherein the disc shaped valve body is equipped further with a thin walled portion in the intermediate annular portion between the fluid supply port and the peripheral portion in the radial direction, and/or with an inflectional portion in the radial direction between the fluid supply port and the peripheral portion.

Abstract: Unidirectional valve for flexible packages, preferably made with laminar plastic materials.

Abstract: There is disclosed a fluid supply valve comprising a disc-shaped valve body which is equipped with a fluid supply port in the central portion thereof and composed of an elastic material whose peripheral portion is reinforced and fixed with a rigid material, the fluid supply port being closed when the valve body abuts against a fixed valve seat placed so as to be opposite to the fluid supply port, and being opened when the valve body is separated from the fixed valve seat, wherein the disc shaped valve body is equipped further with a thin walled portion in the intermediate annular portion between the fluid supply port and the peripheral portion in the radial direction, and/or with an inflectional portion in the radial direction between the fluid supply port and the peripheral portion.

Abstract: The present invention relates to a shut-off valve of limiting flow to a single direction, and a shut-off valve of removing air from the sack and charging the sack with air as well. The shut-off valve has an air passage of a flat and substantially cylindrical form in cross section, which is formed by opposed cladding sheets. The cladding sheet is provided with a valve body sheet which comprises a fixed part attached to the cladding sheet and flap portions with the fixed part placed in the central position therebetween, which flap portions are movable in a vertical direction. One flap portion serves to prevent air from flowing in one direction within the air passage by the close contact with cladding sheet, while the other flap portion serves to prevent air from flowing in the other direction by the close contact with the cladding sheetu The shut-off valve may perform a double function of removing air from the sack and charging the sack with air accordingly.

Abstract: A one-way fluid valve member (10) to be mounted on a valve (12) body having a valve opening (18) surrounded by a valve seat (16). The valve member (10) includes,: a valve closure part (14) to be movably mounted on the body (12) for movement relative thereto between a first position engaging the seat (16) to prevent movement of fluid through the opening (18) in a predetermined direction, and a second position spaced from the seat (16) to allow fluid to pass through the opening (18) in a direction opposite the predetermined direction; and wherein the valve closure part (14) has a convex surface to engage the seat (16) so as to project into the opening (18).

Abstract: There is disclosed a fluid supply value comprising a disc-shaped valve body which is equipped with a fluid supply port in the central portion thereof and composed of an elastic material whose peripheral portion is reinforced and fixed with a rigid material, the fluid supply port being closed when the valve body abuts against a fixed valve seat placed so as to be opposite to the fluid supply port, and being opened when the valve body is separated from the fixed valve seat, wherein the disc-shaped valve body is equipped further with a thin-walled portion in the intermediate annular portion between the fluid supply port and the peripheral portion in the radial direction, and/or with an inflectional portion in the radial direction between the fluid supply port and the peripheral portion.

Abstract: There is disclosed a fluid supply valve comprising a disc-shaped valve body which is equipped with a fluid supply port in the central portion thereof and composed of an elastic material whose peripheral portion is reinforced and fixed with a riqid material, the fluid supply port being closed when the valve body abuts against a fixed valve seat placed so as to be opposite to the fluid supply port, and being opened when the valve body is separated from the fixed valve seat, wherein the disc-shaped valve body is equipped further with a thin-walled portion in the intermediate annular portion between the fluid supply port and the peripheral portion in the radial direction, and/or with an inflectional portion in the radial direction between the fluid supply port and the peripheral portion.

Abstract: A valve arrangement for providing clinical nutrition is provided. The valve arrangement is suitable for use with a rotary peristaltic pump and is capable of allowing flow of fluid in a first direction and capable of preventing flow of fluid in a second direction, wherein the valve arrangement comprises a valve having a cracking pressure of about 0.10 to about 0.20 bar. Also described are a method of production of the valve arrangement, use of the valve arrangement in providing nutrition to a patient and a method of treatment of a patient that comprises administering an effective amount of a composition via the valve arrangement.

Abstract: A silicone rubber diaphragm pump utilizing a pair of MEMS Parylene check valves and a miniature solenoid plunger and actuator is comprised of a spacer sandwiched by a silicone rubber diaphragm on one side and a check valve support on the other. The check valves in the check valve support form the inlet and outlet to a pumping chamber defined between the check valve support and silicone rubber diaphragm. The pumping action has been demonstrated by driving the silicone diaphragm with the plunger using the solenoid type actuator to generate over and under pressures in the chamber. This forces the pumped medium into and out of the chamber, thus allowing the medium to be transported. Tubing or connectors affixed to the inlet and outlet ports of the check valve support structure allow for external fluidic access. The pump works with both gas and liquid.

Abstract: There is disclosed a fluid supply valve comprising a disc-shaped valve body which is equipped with a fluid supply port in the central portion thereof and composed of an elastic material whose peripheral portion is reinforced and fixed with a rigid material, the fluid supply port being closed when the valve body abuts against a fixed valve seat placed so as to be opposite to the fluid supply port, and being opened when the valve body is separated from the fixed valve seat, wherein the disc shaped valve body is equipped further with a thin walled portion in the intermediate annular portion between the fluid supply port and the peripheral portion in the radial direction, and/or with an inflectional portion in the radial direction between the fluid supply port and the peripheral portion.

Abstract: The aerosol container has a container neck (1); a valve disk (5) arranged in the container neck at least partially sealed to its interior wall (12); a valve device (6) secured in the valve disk for dispensing product from an interior space (11); a circumferential sealing element (3) arranged between a facing or top surface (4) of the container neck and a peripheral edge portion (7) of the valve disk; at least one weakly sealed section (10) provided in the container neck (1) near the sealing element (3) and at least one channel (13) provided in interior wall (12) of the container neck (1), extending to the sealing element (3) from the interior space (11) and reaching or ending at the at least one weakly sealed section (10); whereby product can escapes when a pressure in the interior space exceeds a predetermined limiting value. In a preferred embodiment four channels (13) for venting product and four weakly sealed sections are provided spaced 90° from each other around the container neck.

Abstract: The present disclosure describes a Parylene micro check valve including a micromachined silicon valve seat with a roughened top surface to which a membrane cap is anchored by twist-up tethers. The micro check valve is found to exhibit low cracking pressure, high reverse pressure, low reverse flow leakage, and negligible membrane-induced flow resistance when used as a valve over a micro orifice through which flow liquid and gas fluids.

Abstract: A vacuum tank assembly has a low volume configuration so that it can be used in boats and recreational vehicles where space is at a premium. A stack of components, with a waste tank at the bottom, then a vacuum tank with directly connected vacuum pump, and one or more fresh water tanks, is located remote from a vacuum toilet, with a discharge from the toilet (below a vacuum-tight ball valve) connected to the vacuum tank, which is in turn connected to the vacuum pump, in turn connected to the waste tank. A submersible centrifugal pump may be provided mounted to a cap of the water tank, with an anti-siphon device associated with it. The vacuum tank is of high density polypropylene having flat walls, with no continuous flat surface more than 80 square inches. Lipless duckbill check valves are provided on opposite sides of the vacuum pump, the valves of elastomeric material having a ratio of the wall thickness to thickness of the sealing edges of about 1:1.

Abstract: A piston and cylinder air compressor has an induction reed valve including a flat springy reed having end regions which are tiltably supported to hold the reed in closing relationship with an air induction passage of a valve plate whilst permitting deflection and bending of an intermediate region without bending stress at the end regions the valve plate having recesses permitting accompanying tilting of the end regions.

Abstract: A check valve (10) including a valve disk (12), wherein the valve disk (12) is so arranged and configured as to be of a thickness sufficiently substantial to prevent the valve disk (12) from exhibiting a significant amount of flexure even under high reverse pressure, an upper housing portion (16) having an inlet aperture (18) formed therein, a lower housing portion (20) having an outlet portion (22) formed therein, the upper housing portion (16) being formed with a valve seat (24) which protrudes towards the lower housing portion (20) by a preselected distance, the inlet aperture (18) extending through the valve seat (24), a static seal ring (26) for installation between the upper (16) and lower (20) housing portions in sealing fashion, the static seal ring (26) being located circumferentially around and spaced away from the valve disk (12), and a support web (32) extending between the static seal ring (26) and the valve disk (12) for supporting the valve disk (12) from the static seal ring (26), the support

Abstract: A valve assembly has a discharge valve member and a suction valve member. One of these valve members includes a reed valve. The reed valve has a tab which includes a slot which engages a cantilevered pin. The cantilevered pin allows flexing of the pin upon contact with the reed valve. In addition, the cantilever mounting of the pin provides a lubricant reservoir for lubricating the interface between the pin and the reed valve.

Abstract: A method of setting a gap between a poppet member and a seat in a check valve by sensing the position of an cylindrical projection extending from an end cap while sonically welding the end cap to a housing

Abstract: A check valve including a housing formed by a base portion and a cap portion positioned in telescoping relation with each other. A disc shaped valve member is positioned within the housing and is defined by opposing first and second planar sides. The valve member includes a spherical portion located centrally thereon and which is captured between first and second valve supports supported on the base portion and cap portion, respectively. The valve supports hold the valve member in engagement with a valve seat, and the valve member moves out of engagement with the valve seat in response to a fluid pressure applied at a fluid inlet in the base portion to permit forward fluid flow while preventing fluid flow in the reverse direction.

Abstract: A check valve for controlling flow between a low-pressure reservoir and a source reservoir has a pin and an associated diaphragm. The pin has a shaft portion which is attached adjacent to the low-pressure reservoir and a closed head portion. The shaft of the pin has a central channel which opens into the low-pressure reservoir and is connected to the outer surface of the pin by at least one opening in the pin. The diaphragm is made of an elastomeric material and is disposed to tightly fit around, and bias against the surface of the pin. The diaphragm seals around the opening in the pin and is elastically deformable by a predetermined positive pressure to define a pathway from the high-pressure source into the opening in the pin and ultimately into the low-pressure reservoir.

Abstract: A valve assembly has a discharge valve member and a suction valve member. One of these valve members includes a reed valve. The reed valve has a tab which includes a localized through hardened area which provides a wear surface. The remainder to the reed valve has a lower hardness to provide fatigue strength to the reed valve.

Abstract: A check valve which opens and closes a flow path according to pressure differences includes a valve body having a thin annular portion which is flexible in a direction towards an annular seat of a valve body seal member, to close the flow path when seated on the annular seat. A valve body supporting member allows the thin annular portion to bend thereby defining a space between a periphery of the thin annular portion and the seat. A spring applies its elastic force to the valve body so that the valve body is seated on the seat closing the flow path, and a part of the thin annular portion corresponding to a predetermined range of central angles of the annular seat is bent-off the annular seat earlier than the other portions thereof when a pressure greater than the elastic force of the spring is applied to the valve body. Thus, the valve is prevented from being vibrated slightly and accordingly from producing noise when operated.

Abstract: A one-way check valve assembly for use in the filler pipe of a vehicle fuel system to prevent liquid fuel from backing up the filler pipe. The check valve assembly includes a valve member formed from a resilient material, normally biased to a closed position in sealing engagement with the interior surface of the filler pipe flow passage, and forced open during refueling by the flow of fuel through the filler pipe inlet to the fuel tank. In a preferred form the valve member comprises a thin-walled flexible membrane formed in butterfly fashion about a central pivot member in the filler pipe. In an illustrative form the individual wings or sides of the valve member are semi-elliptical and in the closed position are angled downstream from the pivot point, conforming to the filler pipe contour in sealing fashion as angular sections of the flow passage.

Abstract: A combination valve has a pneumatically actuated shut-off valve integrated in a valve housing and operative for blocking and releasing a flow between a valve inlet and a valve outlet. The shut-off valve has a valve member which is spring loaded in a valve closing direction. A check valve is integrated in the valve housing, provides blocking of the flow from the valve outlet to the valve inlet and has a closing member formed by a flat spring. A stroke guard limits an opening stroke of the closing member. The valve member of the shut-off valve is arranged at a side of the flat spring which faces the valve outlet and forming the stroke guard of the check valve. A valve plunger is axially guided in the valve housing and centrally extending through the flat spring, and control piston with which the valve member is connected through the valve plunger is loaded with a suction pressure for opening the shut-off valve and ventilated for closing the shut-off valve.

Abstract: A control valve includes a tubular member and a truncated conical helix spring received in the tubular member. A diverging open end of the helix spring is fixed adjacent to a first open end of the tubular member. The helix spring has a truncated tapered open end opposed to the diverging open end. A plug member is fixed in the truncated tapered open end in order to close the truncated tapered open end. The truncated conical helix spring confines a truncated cone-shaped chamber and is formed of a plurality of turns which are wound in a watertight manner. The helix spring extends and forms a plurality of clearances among the turns under a predetermined axial tension force. The tubular member has two connecting outlet ports which are to be connected respectively to the ends of a transducer in order to measure the differential pressure and thereby measure the flow rate of the fluid which passes through the tubular member.

Abstract: A ring valve assembly for use in a reciprocating type fluid pump with a piston cylinder and a cylinder head includes a ring valve having a fluid seal surface for selectively closing a fluid passage of a cylinder head and an annular ring retainer having a fulcrum edge and tapered top surface. The retainer is positioned beneath the ring valve and a slight clearance is designed in such that the ring valve experiences as a first stage of movement/deflection slight vertical travel. Continued operation of the fluid pump results in a second stage of deflection where the ring valve deflects into a frustoconical shape and lays against the tapered surface of the retainer, pivoting about the fulcrum edge.

Abstract: An apparatus is disclosed for an improved one-way valve comprising a base for mounting in a chamber with a valve surface engaging with a sealing surface to close an input aperture of the chamber. A flexible web is interposed between the base and the valve surface for resiliently biasing the valve surface into engagement with the sealing surface thereby closing the input aperture. When a fluid pressure from the input aperture exceeds the resilient bias of the flexible web, the valve surface is displaced from the sealing surface for opening the input aperture to permit the flow of the liquid from the input aperture through the chamber into an output aperture. Upon a sufficient fluid pressure within the chamber, the valve surface engages with the sealing surface for closing the input aperture to inhibit the flow of fluid from the chamber into the input aperture.

Abstract: A ring valve assembly for use in a reciprocating type fluid pump with a piston cylinder and a cylinder head is disclosed. The valve assembly includes a ring valve having a fluid seal surface for a selectively closing a fluid passage of a cylinder head and bias means for the ring valve for urging the ring valve in a first direction. The bias means includes the outer peripheral edge region of the ring valve being secured between opposing upper and lower annular surfaces with a predetermined smaller clearance. The upper annular surface includes an outer edge and the lower annular surface includes an inner edge which defines a fulcrum radially inward of the outer edge.

Abstract: A check valve for bags containing goods such as rice or other grains or foods. The valve is used to discharge excessive air from the bag while preventing outside air from entering the bag. The check valve is constructed of plural plastic films joined together.

Abstract: There is disclosed an aerosol dispenser (1) comprising a plastics container (2) and a closure which is secured in a fluid tight manner to a neck portion (4) of the container (2). The neck portion has a conformation such that, on deformation thereof by internal pressure at an elevated temperature, the seal between the closure and the container (2) is broken to permit the pressure in the dispenser to be released, while retaining the closure captive on the neck portion (4). Also disclosed is a plastics aerosol container (2) for use in the aerosol dispenser of the present invention.

Abstract: A discharge valve for a compressor having a closed polygonal loop shape and provided with a shutting device formed as a protrusion for tight insertion into a discharge passage, a shutting member in close contact with a valve plate, flexible device continued from the shutting member and providing the shutting member and the shutting device with elasticity, against compressed refrigerant, and a fixing device mounted on an inner ceiling of a cylinder head is disclosed. The discharge valve provides secure opening and closing of the discharge passage and improved compression as well as simple and compact construction.

Abstract: A one-way flow device (10) for use in a passageway (18) is provided. The device (10) comprises first (12) and second (14) walls attached together to form a passageway (18). A flexible diaphragm (20) having at least one orifice (24) extends across the passageway (18). The diaphragm (20) flexes between open and closed positions responsive to flow conditions in the passageway (18). In the open position, the orifice (24) is exposed, allowing fluid flow. In the closed position, the orifice (24) is sealed by the first sheet (12), substantially preventing fluid flow.

Abstract: A valve for dispensing a preferably viscous fluid is adapted in connection with the dispensing operation to open under the action of a positive pressure in the fluid, produced e.g. by means of a pump (1), and to close by itself when the positive pressure, and thus the dispensing operation, has ceased. The valve (2) has a channel (9) with an inlet and an outlet end (9a; 9b) and an axial direction of fluid flow (10). The channel (9) is defined by a body portion (11) of rigid material and a cover portion (12) of flexible material. The body portion (11) is formed with a groove (13) of substantially arcuate cross-section. The edges of the cover portion (12) extending in the direction of flow (10) are sealingly connected to the body portion (11). Towards the outlet end (9b), the cover portion conforms to the shape of the groove (13). The cover portion (12) is prestressed to sealingly engage the wall of the groove (13) with a certain engagement pressure.

Abstract: The piston type metering pump includes a synchronous electric motor, for example of the permanent-magnet type, which transmits its rotary motion to a speed reducer which is in turn associated, by means of a connecting rod-crank kinematic system, to a piston which is slidable in a hollow body in which it defines a variable-volume chamber. The chamber has, at its top, openings on which fluid intake and discharge valve means act.

Abstract: A brake fluid pressure controller is interposed between a master cylinder and the rear wheel cylinders. The controller comprises a housing having an inlet, an outlet and a chamber which provides communication between the inlet and the outlet. An annular sealing member is disposed around a piston in the chamber with a clearance left therebetween. The sealing member has an inner perimeter defining a valve seat and an outer perimeter defining a flexible lip portion which is in contact with the internal wall of the chamber. When a valve head of the piston sits on the valve seat of the sealing member, the inner perimeter of the valve seat cuts off the communication between the inlet and the outlet. Meanwhile, the outer perimeter permits a communication from the outlet to the inlet but shuts off a communication from the inlet to the outlet. A spring urges the piston to a direction in which the valve head separates from the valve seat.