Abstract: An HVAC system includes an evaporator, a heater, a plurality of outlets, and a sliding control door downstream of the evaporator, which is configured to allow air to flow across one or both of a heated path across the heater and a bypass path bypassing the heater. A sliding stratification door is downstream of the temperature control door and positionable to, in an intermediate position, direct air flowing through the bypass path to be mixed with air that flowed across the heated path before flowing out of the plurality of outlets.

Abstract: An integrated display and ventilation assembly includes a display screen and a first air register. The first air register is displaceable between a first stowed position concealed behind the display screen and a first deployed position projecting from behind the display screen. A related method of ventilating a passenger compartment of a motor vehicle is also disclosed.

Abstract: An isolation valve is provided, along with removable shield insert assemblies for an isolation valve. In one embodiment, a shield insert assembly for an isolation valve is provided that includes a graphite first shield insert having a flat ring shape. The first shield insert has a circular outer diameter. An elongated aperture is formed through the first shield insert. At least two fastener holes are formed through the first shield insert configured to couple the first shield insert to a first shield support.

Abstract: A vacuum demand valve for controlling flow of exhalation gases from a patient to a vacuum line. The demand valve comprises: a housing having a housing inlet that allows exhalation gases to flow into the housing from a patient, and a housing outlet that allows gases to flow from the housing into the vacuum line; a diaphragm having a flexible skirt and a rigid portion moveable in response to gas pressure in the housing; a sealing member connected to the rigid portion to engage the housing outlet to resist the flow of gases from the housing to the vacuum line. In a first condition, the vacuum line pressure causes the sealing member to engage the housing outlet and in a second condition a predetermined pressure of exhalation gases in the housing causes the sealing member to disengage from the housing outlet.

Abstract: A valve having a housing with a flow opening with a flat boundary. The flow opening is connected on one side to an elastic film element, which seals the flow opening in the flat state of the element. The valve is used as a throttle element for motor vehicles with diesel engines.

Abstract: The invention relates to an airing and venting valve for pipes and fittings carrying fluid, comprising a substantially cup-shaped valve body becoming smaller in cross-section towards the bottom for closing and opening a valve outlet, with a seal cup co-operating with a float of the valve, and a cup seal which is disposed between the valve body and seal cup and is able to move into different closing and opening positions lying across passage orifices of the valve body. By virtue of one aspect of the invention, the seal cup has an internal contour which becomes wider towards the top conforming to the external contour of the valve body. By virtue of another aspect, the valve body is disposed so that it is able to move against its seat at the valve outlet so that it can release and close a passage in the region of the valve body seat.

Abstract: Both an air mixing door (9) for the cold air for adjusting a passage area of the cold air passage (6); and an air mixing door (10) for the hot air for adjusting a passage area of the hot air passage (7) are composed of a sliding door for adjusting the passage area when the air mixing door (9) for the cold air and the air mixing door (10) for the hot air are slid in a direction perpendicular to the flow of air in both the passages (6, 7), and while one of the air mixing door (9) for the cold air and the air mixing door (10) for the hot air is maintaining one of the passages (6, 7) in a fully opened state, an operating position of the other door is adjusted so that a passage area of the other passage is adjusted and a temperature of the air blowing out into a vehicle compartment is adjusted.

Abstract: The first cold air flow door 26 and the first hot air flow door 24 for adjusting the blowout air temperature are arranged in the first air passage, and the second cold air flow door 27 and the second hot air flow door 25 for adjusting the blowout air temperature are arranged in the second air passage. When a larger target air flow volume between the target air flow volume on the first air passage side and the target air flow volume on the second air passage side is selected so as to determine an air flow volume of the blower, in an air passage to which the smaller target air flow volume is applied, while the ratio of the cold air flow volume to the hot air flow volume is being maintained constant, the passage opening area is throttled by the cold air flow door and the hot air flow door.

Abstract: The invention relates to a control device (1) for controlling airflows in motor vehicles, comprised of a frame having at least one passage opening (4) and at least one controlling means, which is provided in the form of a roller louver (5) and which serves to modify the passage cross-section for the air flowing through the passage opening (4). The frame comprises a housing (2) with at least two hollow bodies (8) that are open along the longitudinal sides. These hollow bodies (8) accommodate the drive shaft (6) or the return shaft (7) for the roller louver (5), and each have a pivotal cover (8.3) for opening the respective hollow body (8). The control device (1) can be mounted inside airflow ducts of a heating and/or air-conditioning system for motor vehicles.

Abstract: A valve includes a film having side edges and an opening to extend across a passage in a housing of a HVAC system. The film has a circular aperture in the film adjacent each rounded corner of each opening for relieving stress. Either or both of the leading edge and the trailing edge of the film are undulated to prevent deformation of the edges. A pair of racks is disposed on the film and sprockets engage the teeth of the racks for moving the racks and the film linearly. Each rack includes a strap and bearing member for retaining the associated sprocket in engagement with the teeth. The bearing member is in rolling engagement with a bearing surface of the associated strap as it rotates with the sprockets.

Abstract: An air passage switching device includes a film member for opening and closing an opening portion of an air passage, and the film member has a first end portion fixed to a peripheral portion of the opening portion and a second end portion fixed to a winding shaft. The winding shaft is capable of moving in a first direction separated from the first end portion of the film member and in a second direction approaching the first end portion of the first member while rotating. In the air passage switching device, an actuator for operating the winding shaft is disposed in an interior of the winding shaft and is fixed by a fixing member, the winding shaft is disposed rotatably relative to the fixing member, and the fixing member is moved in the first direction or the second direction together with the winding shaft by a guide unit.

Abstract: The invention relates to a roller belt cassette for use in a control device (1) serving to control airflows in motor vehicles, comprised of a roller belt subassembly having a roller louver, which is formed by a roller belt (5), and at least two shafts (6, 7) of which one is a drive shaft (6) and the other is a return shaft (7). The roller belt (5) is formed by an endless belt or is provided in the form of an endless belt. The roller belt cassette can be mounted inside airflow ducts of a heating and/or air-conditioning system for motor vehicles.

Abstract: An access fitting has a housing with a base and a cap located respectively on interior and exterior sides of the wall of a gas sampling bag. The base and cap are provided respectively with inner and outer ports aligned with an opening in the bag wall to provide a through passageway communicating with the interior of the bag. A septum is interposed between the cap and the exterior side of the bag wall. The septum has a hole therein and is slidably adjustable between an open position at which its hole is aligned with the through passageway, and a closed position at which its hole is removed from the through passageway and the through passageway is blocked by an imperforate segment of the septum. A tubular connector is received in the outer port, and is axially adjustable between an advanced position frictionally resisting sliding adjustment of the septum, and a retracted position accommodating such adjustment.

Abstract: A valve is constructed to strike a balance between providing relatively high sealing yet low friction as components of the valve move. The valve includes a port and an actuator movable relative to the port. A member is disposed between the port and the actuator. The actuator acts on the member so that it can intermittently seal the port as it moves. The member and the actuator have a substantially low friction interface, whereas the seal member and the port have a substantially high sealing interface. The valve can be used in an engine, such as a rotary valve in an internal combustion engine.

Abstract: Valves, particularly useful for controlling flow of heat transfer fluids in various heating, air conditioning and ventilation systems, are provided. The valves are of the curtain valve type and operate at very low torque and provide easy assembly and repair. The valve or actuator has an adjustment for the flow coefficient. A disclosed valve comprises a valve body having an inside surface, an inlet port comprised of an opening through the inside surface and enabling fluid flow into the valve body, an outlet port comprised of an opening through the inside surface and enabling fluid flow from the valve body, and a curtain valve closure. The closure adjustably controls fluid flow through the outlet port and is of a modular design including a flexible diaphragm held in an insert positioned at least partially within the outlet port. The insert has at least one dimension larger than a mating surface on the internal surface of the valve body.

Abstract: This invention relates to a pressure compensating valve and more particularly, but not exclusively, to a balanced pressure compensating valve, or regulator. The valve includes a chamber (6) for containing fluid, defined by a flexible barrier (2) trapped between first (3) and second (4) surfaces. A fluid inlet provides fluid to the interior of the chamber. A fluid outlet selectively allows fluid to pass out of the chamber. Movement of the first (3) and second (4) surfaces relative to each other causes change in contact between the flexible barrier and the first and second surfaces to selectively open the fluid outlet, in a first position, and occlude it between the flexible barrier and one of the surfaces, in a second position.

Abstract: An air passage opening/closing device includes a film member for opening and closing an opening of an air passage of a case. One end of the film member is fixed to a fixing portion on an outer periphery of the opening of the air passage, and the other end thereof is connected to a film winding shaft. A moving member movable by rotation of a drive shaft is provided on the opening, and the film winding shaft is moved while being rotated by the movement of the moving member, so that the film member at the other end side is wound around and unwound from the film winding shaft. Accordingly, when the air passage is opened and closed by the film member, sliding friction can be prevented from being generated between the film member and the case.

Abstract: A flow control device includes a wall part partitioning an upstream side and a downstream side of a flow passage for fluid, an aperture part formed on the wall part, a sheet shaped valve element which changes from a closed state in which the sheet shaped valve element extends along the wall part to cover the aperture part to an opened state in which the aperture part is opened and a valve element drive mechanism for moving the sheet shaped valve element.

Abstract: An air passage opening/closing device includes a film member for opening and closing an opening of an air passage of a case. One end of the film member is fixed to a fixing portion on an outer periphery of the opening of the air passage, and the other end thereof is connected to a film winding shaft. A moving member movable by rotation of a drive shaft is provided on the opening, and the film winding shaft is moved while being rotated by the movement of the moving member, so that the film member at the other end side is wound around and unwound from the film winding shaft. Accordingly, when the air passage is opened and closed by the film member, sliding friction can be prevented from being generated between the film member and the case.

Abstract: A film valve assembly for a heating, ventilation and air conditioning system includes a frame, two roller mechanisms disposed on the frame, and a film valve disposed between the roller mechanisms under tension. A tension unit includes a tension rod having two ends that are connected respectively to first and second supporting seats on the base wall by first and second retaining units. The first retaining unit includes a spring-biased retaining element that is biased to engage a retaining hole in the first supporting seat.

Abstract: A film valve for an air conditioning system is of the type having two spaced-apart coupling ends, and a plurality of vent holes disposed between the coupling ends. The film valve includes a base layer made of glass fiber and having two opposite side surfaces, and two wear-resistant coating layers applied respectively to the side surfaces of the base layer. Each of the coating layers is made of a material that is selected from the group consisting of silicon, polyurethane, and Teflon.

Abstract: In an air passage switching device using a film-type sliding door for an air-conditioning unit for a vehicle. A grid member is provided in an air passage to extend parallel with the sliding direction of a sliding door and divide an opening of the air passage into a plurality of smaller openings. The sliding door has a film member, a door plate supporting the film member, and elastic pressing means for pressing the film member against edge seal faces of the air passage. A grill spacing between the door plate and the end face of the grid member, is larger than an edge seal face spacing between the door plate and the edge seal faces.

Abstract: An air passage in an air-conditioner such as an automotive air-conditioner is selectively opened or closed by moving a position of an opening formed on a film screen relative to the air passage. The film screen is coupled to a pair of rollers, forming a curved path between the pair of rollers guided by a guiding surface. The film screen is formed by laminating a first film made of resin and a second film made of woven fabric having a higher elongation rate for a temperature rise than the first film. The second film is positioned inside of the curved path to prevent a shape of the roller or the guiding surface from being easily transferred to the film screen.

Abstract: In an air passage switching device, a flexible film moves to traverse an air passage of an air duct, thereby switching and controlling a communication state of the air passage. A thickness t of the film, a glass transition temperature Tg thereof and a radius of curvature r thereof are set so that a relationship expressed by a formula of t≦(0.00578×Tg0.448×r0.333) is satisfied and a bending stiffness of the film is set equal to or higher than 1 &mgr;N·m2. Accordingly, the film can be restricted from being buckling-deformed and from being damaged. As a result, an air leakage amount from a clearance between the film and the air passage due to the deformation can be effectively restricted.

Abstract: Valves, particularly useful for controlling flow of heat transfer fluids in various heating, air conditioning and ventilation systems, are provided. The valves are of the curtain valve type and operate at very low torque and provide easy assembly and repair. The valve or actuator has an adjustment for the flow coefficient. A disclosed valve comprises a valve body having an inside surface, an inlet port comprised of an opening through the inside surface and enabling fluid flow into the valve body, an outlet port comprised of an opening through the inside surface and enabling fluid flow from the valve body, and a curtain valve closure. The closure adjustably controls fluid flow through the outlet port and is of a modular design including a flexible diaphragm held in an insert positioned at least partially within the outlet port. The insert has at least one dimension larger than a mating surface on the internal surface of the valve body.

Abstract: A gate assembly for a hopper of a transport vehicle has an open position in which the gate lies substantially in a vertical plane adjacent to the hopper wall and a closed position in which the gate lies substantially in a horizontal plane. The gate moves longitudinally in guides between the two planes. Several gates can be located adjacent to one another to retain or discharge particulate material in several hoppers separated by partition walls.

Abstract: A vent valve for use in controlling discharge of fuel vapor from a fuel tank. The vent valve includes a housing for attachment to the fuel tank includes a wall defining a cavity therein. The float is contained in the cavity of the housing and is responsive to the level of liquid in the fuel tank. The level in the fuel tank rises, the float rises within the housing. When the level of liquid in the fuel tank drops, the float moves downwardly in the housing. A passage is provided in the housing which communicates with an external portion of the tank. The vent valve includes at least one vent positioned proximate to and communicating with the passage for providing venting passage of vapor therethrough and to the passage. The vent valve includes a vent assembly having a flexible diaphragm which is displaceably positioned proximate to the passage to control the flow of vapor through the vent and through the passage.

Abstract: A tank vent valve apparatus includes a valve housing formed to include an inlet port, an outlet port, and an interior region. The interior region is partitioned to define an intake chamber communicating with the inlet port, a discharge chamber communicating with the outlet port, and a float chamber containing a vent port valve and receiving liquid fuel and fuel vapor from the intake chamber. An interior wall defines a boundary between the float chamber and the discharge chamber and includes a valve seat formed to include a vent port therein. The vent port valve is buoyant and moves up and down along the interior wall as liquid fuel rises and falls in the float chamber to close and open the vent port.

Abstract: This invention relates to a shutter device for the precision control of a flow, comprising at least one organ for shutting a section for the passage of a flow, the motion of which is proportional to that of an actuator controlling it, wherein said device comprises at least two shutter organs controlled by the actuator by means of a transmission allowing to obtain slightly different proportionality coefficients for the motion of said organs.

Abstract: A valve for the accurate control of fluid flowing through the valve. The valve has a valve body and a flow control mechanism. The valve body is a two-part body having a fluid flow section and a valve adjustment section. The fluid flow section has a fluid flow cavity. The fluid flow cavity further includes a flow control orifice area, which flow control surface being smaller in cross-sectional area than the fluid flow cavity. The flow control mechanism is able to vary the length of its major axis via a force provided by the valve actuator. As the major axis of the flow control mechanism decreases, the minor axis of the flow control mechanism increases at an amplified rate, said increase in the minor axis of the flow control mechanism accomplishes flow control and in combination with the valve actuator, flow control and fluid modulation.

Abstract: An air passage in an air-conditioner such as an automotive air-conditioner is selectively opened or closed by moving a position of an opening formed on a film screen relative to the air passage. The film screen is coupled to a pair of rollers, forming a curved path between the pair of rollers guided by a guiding surface. The film screen is formed by laminating a first film made of resin and a second film made of woven fabric having a higher elongation rate for a temperature rise than the first film. The second film is positioned inside of the curved path to prevent a shape of the roller or the guiding surface from being easily transferred to the film screen.

Abstract: The present invention provides anchor tabs at opposite ends of a film member that are anchored to side faces of a door plate of a sliding door. Draft deflectors prevent the inflow of air to between the anchor tabs and the side faces of the door plate. Thus, inflow of air to between the anchor tabs of the film member and the side faces of the door plate is prevented. Also, fluctuations in pressure difference between the inner and outer sides of the anchor tabs are suppressed, and the production of extraneous noise caused by self-excited vibration of the anchor tabs at the ends of the film member is suppressed.

Abstract: In an air conditioning apparatus for a vehicle, a first cool air bypass passage is provided at an upper side of a heater core, and a second cool air bypass passage is provided at a lower side of the heater core. Cool air from the first cool air bypass passage and warm air having passed through the heater core are mixed in a first air mixing chamber, and a ratio between an amount of cool air and an amount of warm air is adjusted by an air mixing film member. Further, cool air from the second cool air bypass passage and warm air from the heater core are mixed in a second air mixing chamber, a ratio between an amount of cool air and an amount of warm air is adjusted by an air mixing door, and the second air mixing chamber is provided at an immediately downstream air side of the heater core. Thus, in the air conditioning apparatus, a pressure loss in a ventilation system can be reduced.

Abstract: The valve is enabled, by being endowed with the force of stored energy, to generate an opening/closing motion with a small operating torque infallibly and stably, permit a reduction in cost, allow a compact construction, excel in durability, and enjoy a highly satisfactory practical value. Further by endowing the valve body which has already acquired the function of water stop with the function of steady flow volume thereby diversifying functionality, the valve is enabled to acquire the function of varying steady flow volume by virtue of the rotational frequency of the spiral spring.

Abstract: In an air passage opening/closing device for a vehicle air conditioner, a driving member is disposed to apply driving force for a reciprocating movement of a film member to at least one position of the film member, and a guide member is provided in an air-conditioning case to guide the reciprocating movement of the film member. The film member has a flexible performance to move in a bend path, and has a rigidity to be moved along the guide member when pushing force from the driving member is applied to the film member. Thus, the air passage opening/closing device using the film member has a simple structure without a film-winding mechanism.

Abstract: A float operated fuel tank vent valve has a pair of vent passages with one of the pair larger than the other. A thin flexible elastomeric strip valve has one end attached to the valve body and the distal end bent over the top of the float and attached thereto. The strip valve has a pair of annular sealing surfaces formed thereon each disposed respectively opposite one of the vent passages. Upon refueling of the tank, as the float rises, the strip valve first progressively closes the larger vent passage and then progressively closes the smaller vent passage. As fuel is drawn from the tank by engine operation and the float is lowered, the strip valve is first peeled away from one edge of the smaller vent passage and then completely opens the smaller vent passage. As the float is further lowered, the valve strip is peeled away from one edge of the longer vent passage and then completely open the larger vent passage.

Abstract: An electrically controllable valve comprising at least one input port (13) and one or more output ports (12, 14), at least one sealing means (17, 18) being arranged to control the flow of a fluid between said input port and at least one of said output ports, said valve comprises one or more piezo-electric actuators (26) arranged to control the state of said sealing means, whereby the flow of fluid through said valve may be electrically controlled.

Abstract: A water flow timer comprising a main body, a water stopping membrane, a control rod, a bottom cover, a control member, a rotating member, a timing member, and a rotary cap, the timer is mechanically operated in such a way that the rotary cap is turned to actuate the control member to force the control rod to slide, thereby resulting in a gap between the water stopping membrane and a bottom opening of an inner chamber of the main body. The inner and the outer chamber of the main body are thus in communication with each other. As the rotary cap is turned, the torsion spring of the timing member is compressed to provide the rotary cap with a recovery force. The recovery of the rotary cap is delayed by an intermittent gear, so as to control the timing of the water flow.

Abstract: A variable orifice valve for controlling fluid flow in a conduit, comprising a band or other movable members defining an opening for passing the fluid therethrough, the band mounted transverse to the direction of fluid flow in the conduit, so that the band opening is at least partially in the conduit. The band is movable relative to the conduit, to change the amount of the opening exposed to fluid flow.

Abstract: In an air passage switching device, suitable for use for example in a vehicle air conditioning apparatus, for switching a flow of air among a plurality of air passages by moving a film door in one direction by a stepping motor and in another direction by the spring force of coil spring, when the film door is moved in the direction in which it winds up the coil spring the pulse rate of the stepping motor is reduced to thereby increase the motor torque and prevent the occurrence of a shortage of motor torque. When the film door is moved in the other direction the pulse rate of the stepping motor is increased to reduce the motor torque.

Abstract: A vehicle air-conditioning system that independently controls left-right air flow distribution in correspondence with left and right heat loads during a maximum cooling mode. In the system, blowout air flow is increased when driver seat side and passenger seat side air-mixing film members are both positioned in a maximum cooling position, and the heat load has risen in only one of a driver seat side space and a passenger seat side space in a passenger compartment. Further, each respective film member is operated to fully open a cool air bypass passage on the side on which the heat load has risen and the respective film member corresponding to the side on which the heat load has not risen significantly is operated to reduce the open area of the cool air bypass passage. At the same time, fan speed is increased to increase the air blow amount.

Abstract: An air release valve comprising a housing having a fluid inlet and a fluid outlet, a valve plate within the housing between the inlet and outlet, the valve plate having an aperture therein; a valve seal assembly including a reinforced portion engageable with the valve plate overlying the aperture and a flexible portion having an elongated groove formed therein and at least partially overlapping an edge of the aperture; one end of the valve seal assembly secured to the housing; a float located in the housing upstream of the valve plate, with the opposite end of the seal assembly connected to an upper end of the float.

Abstract: A band controlled valve apparatus for controlling fluid flow from a source to a sink, including a base (12) having an upper surface and an aperture (16) extending from the upper surface through the base (12) allowing the flow of fluid from the source through the base (12) to the sink when the aperture (16) is not covered, an elongate flexible band (8) with a first portion (8a) in contact with the upper surface of the base (12) and a second portion (8b) extending forwardly of the first portion (8a) then upwardly and rearwardly above at least a part of the first portion (8a), the second portion (8b) being actuated to selectively move the second portion (8b) of the band (8) forwardly or rearwardly to cover or uncover, respectively, the aperture (16) with the first portion (8a) of the band (8) to thereby prevent or allow, respectively, fluid flow through the aperture (16).

Abstract: In an air passage switching device using a film-type sliding door for an air-conditioning unit for a vehicle. A grid member is provided in an air passage to extend parallel with the sliding direction of a sliding door and divide an opening of the air passage into a plurality of smaller openings. The sliding door has a film member, a door plate supporting the film member, and elastic pressing means for pressing the film member against edge seal faces of the air passage. A grill spacing between the door plate and the end face of the grid member, is larger than an edge seal face spacing between the door plate and the edge seal faces.

Abstract: The present invention provides anchor tabs at opposite ends of a film member that are anchored to side faces of a door plate of a sliding door. Draft deflectors prevent the inflow of air to between the anchor tabs and the side faces of the door plate. Thus, inflow of air to between the anchor tabs of the film member and the side faces of the door plate is prevented. Also, fluctuations in pressure difference between the inner and outer sides of the anchor tabs are suppressed, and the production of extraneous noise caused by self-excited vibration of the anchor tabs at the ends of the film member is suppressed.

Abstract: A band controlled valve apparatus for controlling fluid flow from a source to a sink, including a base (12) having an upper surface and an aperture (16) extending from the upper surface through the base (12) allowing the flow of fluid from the source through the base (12) to the sink when the aperture (16) is not covered, an elongate flexible band (8) with a first portion (8a) in contact with the upper surface of the base (12) and a second portion (8b) extending forwardly of the first portion (8a) then upwardly and rearwardly above at least a part of the first portion (8a), the second portion (8b) being actuated to selectively move the second portion (8b) of the band (8) forwardly or rearwardly to cover or uncover, respectively, the aperture (16) with the first portion (8a) of the band (8) to thereby prevent or allow, respectively, fluid flow through the aperture (16).

Abstract: A safety valve to stop flow in the flow pipe (3), the safety valve including a drilling device (8) with its frame (6) to drill a hole in the flow pipe, a winding device (7) fixed to the frame of the drilling device and a band (4) wound with a winding device. The safety valve includes a sleeve to which sleeve a drilling device (8) and a winding device (7) have been fixed and the sleeve has been equipped with systems to fix it to the outside surface of the pipe (3).

Abstract: A valve for maintaining a given level of liquid in a tank, reservoir, or other container having a liquid-gas interface. Said valve being actuated by a float that rises and falls along with the liquid in the container. Said valve float actuates a series of valves in sequence wherein the higher the float rises, the more valve ports are opened allowing a higher flow rate through the valve.

Abstract: A gas flow control valve configured to facilitate back-to-back mounting with a second, similarly constructed valve. The gas valve includes a valve body defining an inlet port and an outlet port, the inlet and outlet ports being surrounded by seal forming O-rings of different diameters. Flanges surrounding the inlet and outlet ports are configured with distinct attachment features for accommodating bolts for securing one valve in series with another or with a pipe flange or other auxiliary device, the inlet flange having either a slot dimensioned to hold and prevent rotation of a bolt head or nut, or a clearance slot permitting use of a wrench, and the outlet flange having the other slot configuration.

Abstract: A band controlled valve apparatus for controlling fluid flow from a source to a sink, including a base (12) having an upper surface and an aperture (16) extending from the upper surface through the base (12) allowing the flow of fluid from the source through the base (12) to the sink when the aperture (16) is not covered, an elongate flexible band (8) with a first portion (8a) in contact with the upper surface of the base (12) and a second portion (8b) extending forwardly of the first portion (8a) then upwardly and rearwardly above at least a part of the first portion (8a), the second portion (8b) being actuated to selectively move the second portion (8b) of the band (8) forwardly or rearwardly to cover or uncover, respectively, the aperture (16) with the first portion (8a) of the band (8) to thereby prevent or allow, respectively, fluid flow through the aperture (16).