Abstract: A water-saving switch equipment, which arranged in the outlet of a tap body, includes a button arranged in the button groove of the tap body, and a water-saving piece arranged under the button. The water-saving piece has a piece which is in the chamber of the outlet. The water-saving switch equipment may adjust the water output without switching on or off the tap's spool.

Abstract: A variable orifice for use in connection with a conduit designed to convey particulate material comprising a set of semi-circular plates mounted on respective concentric shafts so that they may be rotated in opposite directions between a first position in which they extend across the interior of the conduit for maximum flow resistance to a second folded condition where they are adjacent and parallel to one another to present minimum flow resistance. An actuator is connected through the concentric shafts to the plates and mounts on the outside of the conduit surface. The unit is operated by hand crank and has a position indicator. The size of the valve plates is such that, even when fully extended relative to one another and lying across the cross-section of the conduit, only about a 30% restriction is produced.

Abstract: The gas flow restrictor includes a cylindrical body having threads for mounting the body in a gas flow line. One end of the body is closed and includes a plurality of angularly spaced plugs having a predefined diameter that may be the same or different from each other. Each plug is selectively removable from a correspondingly sized orifice, singly or in combination, to set the desired gas flow and thereby reduce incoming gas flow pressure through the lines.

Abstract: A spring-actuator assembly (10) is provided for a fuel pressure regulator. The assembly includes a housing (30) and a washer spring (10) received in the housing. The washer spring has a body (12) with a top surface (13) and a bottom surface (15). The body includes an opening (14) there-through and a plurality of pleats (16, 16?) therein so that that first faces (20) of the top surface are disposed on a plane that is different from a plane of second faces (22) of the top surface. At least certain first faces define contact points (24). The assembly also includes an actuating member (26) disposed at least partially in the opening and engaging the contact points of the certain first faces such that a fluid flow passage (36) are defined between the washer spring and the actuating ball for dampening.

Abstract: An air duct includes a top panel and a blocking member rotatable secured to the top panel. A through hole is defined in the top panel, and a pair of clipping portions are located an edge of the through hole. The blocking member includes an operating portion and a blocking portion connected to the operating portion. The operating portion is located on an outside of the top panel, and the blocking portion is located on an inside of the top panel. The operating portion of the blocking member is passed through a bottom surface of the top panel through the through hole, extends to a top surface of the top panel, and engaged with the pair of clipping portions.

Abstract: A variable pressure reducing device includes a hollow housing body formed with an inlet opening, an outlet opening spaced apart from the inlet opening, and an inner wall surface. The variable pressure reducing device further includes an intake tube that extends into the housing body from the inlet opening. The intake tube is formed with an inlet channel and is further formed with an outer tube surface that cooperates with the inner wall surface to form an outlet channel in fluid communication with the outlet opening. The variable pressure reducing device also includes a redirection structure movably mounted in the housing body and movable relative to the intake tube between a redirecting state and a sealing state.

Abstract: A differential pressure regulating device is provided for controlling in-vivo pressure in a body, and in particularly in a heart. The device may include a shunt being positioned between two or more lumens in a body, to enable fluids to flow between the lumens, and an adjustable flow regulation mechanism being configured to selectively cover an opening of the shunt, to regulate the flow of fluid through the shunt in relation to a pressure difference between the body lumens. In some embodiments a control mechanism coupled to the adjustable flow regulation mechanism may be provided, to remotely activate the adjustable flow regulation mechanism.

Abstract: A series of compressible members disposed with a vessel lumen designed to produce a flow rate that increases with respect to an increasing flow material pressure with the rate of increase having a stepped behavior. The first compressible member is designed so as to partially restrict flow so as to allow for only moderate increases in flow rate with respect to flow material pressure. Subsequent compressible members are designed to allow for increases in flow rate greater than the moderate rate of increase when the flow material pressure is above a given flow material pressure.

Abstract: A green building is disclosed. The green building includes at least one plant growing area with plants, at least one lighting device and a heat pump. The lighting device radiates light onto the plant growing area. The heat pump receives environmental heat.

Abstract: The present invention relates to a regulating device (1) for regulating a fluid flow, the regulating device (1) comprising an actuator element (3) which is provided with a flow area (4) arranged to convey fluid between a fluid inlet (9) and a fluid outlet (13) and which includes a first restriction device (17), and a regulating device body (5) which is disposed at least in a portion of the flow area (4) and which is provided with a second restriction device (19) forming, together with said first restriction device (17), the restriction unit or choke device (17, 19) of the regulating device (1), the actuator element (3) and regulating device body (5) being arranged to move freely independently of each other as a consequence of a material expansion or material contraction, the throughput of the choke device (17, 19) being influenced by an energy source (21) which is arranged to supply energy to at least one of the actuator element (3) and/or regulating device body (5).

Abstract: In one embodiment as described in this section, an apparatus for mixing of microfluidic streams on a chip is presented, which comprises a micro-channel and a plurality of magnetic valves on the chip. A guiding magnet produces a proximal magnetic field gradient to exert a force on a bead in a cavity when placed at in a vicinity of the chip. The bead-cavity combination form a magnetic valve. In one embodiment, the mouth of the cavity is tapered so to prevent the magnetic bead from completely blocking the corresponding micro-channel section to enhance the mixing of microfluidic streams at the narrowed fluid path. In one embodiment, magnetically actuated valves direct the flow in a microfluidic system in one of several flow paths wherein the mixing characteristics of the paths are different.

Abstract: The invention relates to a diaphragm (1) for throttling a volume flow in an air distribution ducting system of an air-conditioning unit of a commercial aircraft. The diaphragm includes a plurality of spring-elastic elements (10) that effect a throttling of the volume flow through the diaphragm (1). The invention also relates to the use of such a diaphragm (1) for installation in an air distribution ducting system of an air-conditioning unit on board a commercial aircraft.

Abstract: A water saving device for use at or near a water outlet has a first water flow regulating element; a second water flow regulating element disposed downstream of the first regulating element; and a chamber formed between the first and second regulating elements. All of one or more water flow regulating parts of the second regulating element are made from substantially solid material.

Abstract: This Invention relates to a kind of devices with no emission resulted for treatment of exhaust gas. The Device comprises a vessel having openings that serve only as inlet. At least two exchange sections are provided inside the vessel after inlet of exhaust gas. There is a gas chamber at each connection part between two sequential sections. The gas exchange chamber at the first gas exchange section has a through opening leading to outside atmosphere area, and at each one from the second to the last exchange section, there is a feedback pipe to connect to the inlet of the first stage of exchange section. With this configuration, on entering into the exchange section, exhaust gas will be ejected inwards and causes very strong entrainment, which makes the gas chamber become vacuum and sucks air with oxygen from atmosphere into gas chamber via the through opening to atmosphere.

Abstract: A flow regulator includes a flow regulating part configured to receive at an inlet a working fluid at a first pressure and to release the working fluid at an outlet at a second pressure; a slide provided inside the flow regulating part and configured to move along an axis to reduce the pressure of the working fluid; a control part attached to the flow regulating part, the control part including a chamber; a spring housing provided in the chamber and connected to the slide though a shaft, the spring housing configured to move the slide along the axis; a cap provided in the chamber and facing the spring housing, the cap being configured to have plural blind holes; and plural pins extending along the axis and attached to the spring housing, the plural pins being configured to enter the plural blind holes.

Abstract: A device for delivering gas is disclosed. The device may include a chamber and a guide. The chamber may include a set of input openings for receiving the gas and an output opening for providing the gas. The set of input openings may include a first hole and a second hole. The chamber may receive a first portion of the gas through the first hole and a second portion of the gas through the second hole. The guide may include a guiding unit. The guiding unit may be disposed inside the chamber. The guiding unit may contact the first portion of the gas before the first portion of the gas contacts the second portion of the gas and may contact the second portion of the gas before the second portion of the gas contacts the first portion of the gas.

Abstract: A hydraulic pressure reservoir having at least one pressure chamber formed between two opposed, movable inner boundary members. Each inner boundary members includes a spring cover and a diaphragm spring. An outer boundary member peripherally surrounds the movable inner boundary members and has a U-shaped cross section along at least a part of its periphery to axially support the diaphragm springs in a fixed axial position. The outer boundary member can be formed in several pieces that are held together by interconnections or by a surrounding outer tensioning member.

Abstract: An elongate flow tube having an interior cross-section surrounding a long axis, an inlet end for receiving a fluid flow and an outlet end for discharging the fluid flow, and a diffuser plate spanning the interior cross-section to separate the flow tube into an inlet chamber and an outlet chamber. The diffuser plate includes a plurality of apertures formed therein for directing the fluid flow from the inlet chamber to the outlet chamber. Furthermore, the diffuser plate is orientated longitudinally at a shallow angle with respect to the long axis of the flow tube to provide an indeterminate pulsation reflective surface, with the inlet chamber gradually decreasing in cross-sectional area and the outlet chamber gradually increasing in cross-sectional area across the length of the flow tube.

Abstract: A tubular member having at least one drainage section (1) including a first plurality of self-adjustable valves or flow control devices (2) to control the flow of fluid into the drainage section from a well formed in a subterranean reservoir, each of the valves (2) comprising an inlet or aperture (10), thereby forming a flow path (11) through the control device (2) passing by a movable disc or body (9) designed to move freely relative to the opening of the inlet and thereby reduce or increase the flow-through area (A2) by exploiting the Bernoulli effect and any stagnation pressure created over the disc (9), whereby the valve (2), depending on the composition of the fluid and its properties, autonomously adjusts the flow of the fluid based on a pre-estimated flow design. To allow injection of fluid into the subterranean reservoir, the drainage section (1) is provided with a second plurality of such self-adjustable valves (32), each being situated in a direction opposite of the first plurality.

Abstract: A modularly structured unit is comprised of a flow resistance element and an orifice plate adjacent thereto, preferably for use in the main flow duct of a thermal mass flow rate measuring or control device. The flow resistance element can be combined with various orifice plates having different opening diameters.

Abstract: In a cooling system, a variable inline nozzle controls the flow of cooling fluid. The variable inline nozzle includes a composite fibrous tube through which the cooling fluid flows. Upon manipulation of the composite fibrous tube, a diameter of a portion of the composite fibrous tube is adjusted to control the flow of the cooling fluid.

Abstract: For both adjustable flow restrictors D1, D2 having variable cross-sections a common adjustment element 21 is provided mechanically coupling the restrictors in a hydraulic damping assembly D for regulating parameters of a regulating system S, in particular of a variable displacement pump P, the restrictors D1, D2 being provided in discharge paths 12, 13 such that the restrictor cross-sections can be varied within an adjustment stroke h. The common adjustment element 21 allows to simultaneously and oppositely vary the flow restriction cross-sections A of both flow restrictors having a variable cross-section. The restrictor cross-sections A of both flow restrictors D1, D2 having a variable cross-section of a hydraulic damping assembly S in a regulating system S of a variable displacement pump P can be varied simultaneously and oppositely according to an imminent specification of the system set by the manufacturer.

Abstract: A choke assembly. In some embodiments, the choke assembly includes a choke element having a fluid flow passage therethrough. The choke element includes a cage having a plurality of apertures therethrough for the passage of fluid and a plug moveable with respect to the cage. The plug has an end surface that defines a boundary of the fluid flow passage through the choke and is moveable to open or close each of the apertures through the cage, whereby the flow of fluid through the cage is controlled. The apertures in the cage are disposed in a first portion and a second portion separated by a land. Each of the first and second portions has a least one aperture therein. The plug may be positioned with its end surface disposed to intersect the land, such that each aperture is fully open or fully closed to the flow of fluid.

Abstract: A flow modulating device comprises flow modulating elements 8 of a shape memory alloy, which are acted upon by resilient elements 10. The flow modulating elements 8 and resilient elements 10 are mounted on a common support ring 6. At one temperature, the flow modulating elements 8 overcome the resilient force of the resilient elements 10 to lie against the wall of a duct 4 in which the device is situated. The flow modulating elements 8 thus offer a relatively low resistance to flow in the duct 4. At a second temperature, the force of the resilient elements 10 overcomes that of the flow modulating elements 8 to deflect them inwardly of the duct 4, so increasing the flow resistance of the device.

Abstract: An annular elastomer is provided in a housing orifice that does not require a large force for deformation. This makes possible a solenoid-type actuator that provides a large displacement of the elastomer, thus allowing higher and lower rates of gas flow through a gas line.

Abstract: Disclosed herein is an inline valve. The inline valve includes, a housing, a choke member in operable communication with the housing, a portion of the choke member being substantially immobile relative to the housing and a portion of the choke member being mobile relative to the housing. The inline valve further includes, an actuator in operable communication with the movable portion of the choke member, the actuator selectively causing the choke member to deform radially.

Abstract: A hydraulic restrictor comprising: a passage along which hydraulic fluid flows; a member which extends along the passage, the member restricting the flow along the passage; and structure for selectively securing the member at a plurality of different positions along the passage thereby to enable variation in the restriction on flow along the passage, the securing structure securing the member at each position by securing the member against the side wall of the passage.

Abstract: An insertable component that is embodied as a non-return element and/or as a through-flow regulator is provided which can be inserted into a gas or liquid line. The insertable component (1) includes a housing (2) formed of at least two housing parts (3, 4). A housing seal (5) is located between the housing parts (3, 4). The housing seal is joined as a single piece to an annular membrane (11), which is used as a closing body for the non-return element, and/or a regulating or throttle body. The insertable component includes a small number of individual parts and is characterized by a compact structure and low production costs.

Abstract: A method of blocking a water out zone in a production well includes the steps of connecting a throttle unit to a dump bailer, wherein the throttle unit is internally defined a flowing space, which can be adjusted in size to thereby control a flow rate of cement for blocking the water out zone; loading the cement into the dump bailer; slowly lowering down the loaded dump bailer to the water out zone in the production well; opening an outlet of the dump bailer under control, so that the cement flows from the dump bailer into the throttle unit and is released at a flow rate preset by adjusting the size of the flowing space; allowing the released cement to load up in the water out zone and slowly permeate into a gravel layer in the production well before becoming cured to block the water out zone.

Abstract: A novel apparatus and associated methods for controlling the flow through a flow restrictor using a reshapable lumen. The lumen reshapes as a function of the pressure differential over the flow restrictor. Because flow rate is proportional by the fourth order of magnitude to the diameter of the lumen, small changes in the pressure differential allow for larger changes in the flow rate over conventional flow restrictor systems and provides for real time, fine-tuned adjustments to the flow rate.

Abstract: A vacuum control system allows the degree of vacuum in a vacuum vessel to be kept constant while removing vaporized components degassed into the vacuum vessel through a gas permeation diaphragm by stably introducing a very small amount of air into a vacuum exhaust path of the vacuum vessel. The vacuum control system controls the rotary power of a DC brushless motor, continuously controls displacement of a vacuum pump, and thus keeps the degree of vacuum in a vacuum vessel constant, by decompressing the inside of the vacuum vessel using an exhaust vacuum pump which operates with the DC brushless motor, monitoring the inside pressure of the vacuum vessel using a pressure sensor, and controlling a voltage applied to the DC brushless motor on the basis of an output signal resulting from measurement of the inside pressure of the vacuum vessel by the pressure sensor.

Abstract: A feed gas conditioner.

Abstract: A pulsation absorber is provided in a fluid channel formed in a body of a fluid coupling. Fluid flows through the fluid channel in an assembled state. The pulsation absorber is arranged to deform in a same direction as the fluid to flow in the fluid channel pulsates. The pulsation absorber thereby absorbs pulsation of the fluid.

Abstract: A series of compressible members disposed with a vessel lumen designed to produce a flow rate that increases with respect to an increasing flow material pressure with the rate of increase having a stepped behavior. The first compressible member is designed so as to partially restrict flow so as to allow for only moderate increases in flow rate with respect to flow material pressure. Subsequent compressible members are designed to allow for increases in flow rate greater than the moderate rate of increase when the flow material pressure is above a given flow material pressure.

Abstract: The present invention relates to a regulating device (1) for regulating a fluid flow, the regulating device (1) comprising an actuator element (3) which is provided with a flow area (4) arranged to convey fluid between a fluid inlet (9) and a fluid outlet (13) and which includes a first restriction device (17), and a regulating device body (5) which is disposed at least in a portion of the flow area (4) and which is provided with a second restriction device (19) forming, together with said first restriction device (17), the restriction unit or choke device (17, 19) of the regulating device (1), the actuator element (3) and regulating device body (5) being arranged to move freely independently of each other as a consequence of a material expansion or material contraction, the throughput of the choke device (17, 19) being influenced by an energy source (21) which is arranged to supply energy to at least one of the actuator element (3) and/or regulating device body (5).

Abstract: A fluid flow regulating mechanism designed particularly for use in connection with aerosolized drug delivery devices is disclosed. The mechanism includes a housing, planar elastic element, regulating element and positioning component. The elements of the device are configured in a manner such that a flow channel through the housing is opened or closed depending on the flow rate of fluid through a flow channel.

Abstract: A height control valve for an air spring of an air-ride axle/suspension system of a heavy-duty vehicle includes a body. The valve body is pneumatically connected to an air reservoir of the vehicles an ail spring, and to atmosphere A control arm actuates the valve to direct air from the reservoir into the air spring, when air is to be added to the air spring When air is to be exhausted from the air spring, the valve, actuated by the control arm, directs air from the air spring to atmosphere The valve includes a throttle assembly that can regulate the rate of pneumatic flow from the air spring to atmosphere when the vehicle is loaded and the air spring is in an extended condition. A throttle assembly can also be used to regulate the rate of pneumatic flow from the air reservoir to the air spring.

Abstract: A medical apparatus flow restrictor includes a housing having an inlet housing member defining an inlet and a separate outlet housing member mated with said inlet housing member and defining an outlet from the flow restrictor. A fluid path is defined through the housing members between the inlet and outlet. Opposed flow restriction surfaces are defined between at a location along the fluid path such that fluid delivered to the inlet passes between the opposed flow restriction surfaces prior to flowing from the outlet. The opposed flow restriction surfaces have a relative degree of surface roughness and opposed surface area defined as a function of a desired flow rate of fluid through the restrictor.

Abstract: A method comprises applying a thermal activation signal to a conduit comprising a shape memory polymer, causing a change in at least one property of the shape memory polymer, and regulating fluid flow through the conduit by the change in the at least one property of the shape memory polymer. A conduit comprises a shape memory polymer in an amount effective to regulate fluid flow through the conduit by a change in at least one property of the shape memory polymer caused by application of a thermal activation signal. The conduits and methods disclosed herein may find use as drinking utensils, respirator tubes, pump intake tubes, motor vehicle cooling system bypass hoses, motor vehicle engine oil filter bypass hoses, or motor vehicle powertrain fluid circulation hoses.

Abstract: A breather for a driveline component such as an axle, for example, includes a rigid body portion attached to an axle housing, an extension portion attached to the rigid body portion and extending into a housing cavity, and a conical spring supported by the extension portion. The rigid body portion has an internal bore that extends from a first body end to a second body end with the first body end extending outwardly from the axle housing and the second body end being fixed to the axle housing. The extension portion has a non-uniform cross-sectional area, and includes an extension bore with a large internal diameter. The conical spring is received within the extension bore and cooperates with the extension to prevent lubricating fluid from exiting the breather while still allowing air to vent through the breather as needed.

Abstract: A flow control device that is uniquely capable of providing uniform flow under changing environmental conditions of temperature and pressure. The device achieves flow rate stabilization by taking advantage of the properties of the moving fluid in a channel with eddy currents that are generated as fluid moves past obstacles located in the fluid flow path. The shape and magnitude of such eddies depend on the viscosity of the fluid. Additionally, the device can also simultaneously stabilize the fluid flow rate under varying pressure by using a strategically positioned, yieldably deformable elastomeric membrane. Therefore, the invention uniquely combines two devices into one novel fluidic device that can stabilize a flow rate under simultaneously changing temperatures and pressures.

Abstract: A flow regulator (50) having a controller housing (1) which has a central body (3) in a passage channel (2) is provided, with the central body (3) being bounded by an annular throttle body (4) made from an elastic material that delimits a control gap (6) between itself and an adjacent peripheral lateral surface (5) which is provided with control recesses (7, 7?) that are spaced apart from one another in the circumferential direction and are oriented in the flow direction (Pf1, Pf2), with the passage cross-section of the control gap (6) being variable via the throttle body (4) deforming under the pressure difference created as the flow passes through.

Abstract: A rotary control valve is provided. The valve includes a valve body having a first valve member with a first volute formed therein, wherein the first volute further includes a plurality of flow channels of varying diameter or a single flow channel having a generally smooth gradient from large to small diameter; and a second valve member in close proximity to or in direct contact with the first valve member with a second volute formed therein, wherein the second volute further includes a plurality of flow channels of varying diameter or a single flow channel having a generally smooth gradient from large to small diameter. The first and second volutes cooperate with one another to form an orifice between the first and second valve members, and the diameter of the orifice is variable based on the positions of the individual flow channels relative to one another.

Abstract: The invention relates to a sanitary component, namely a stream regulator or stream former for flowing fluid media, consisting of property-defining components in a sandwich-like arrangement in the direction of flow which comprise at least one screen attachment, one diffuser plate assembly as well as a shell body having segments of stream-forming openings extending across its cross-sectional surface. The property-defining components are exchangeable and combinable so as to realize adaptability to different user and user requirements. A locking means is provided e.g. on the inner circumference of the shell body for this purpose as is a corresponding counter-locking means on the outer circumference of the diffuser plate assembly. The diffuser plate assembly exhibits, at least on its exterior, a flow rate class-specifying optical code and the shell body exhibits a stream type-specifying, namely laminar or aerated, optical code.

Abstract: A linearly self-actuated hose for use in transporting fluids (liquids, gases, solid particles, and combinations of these three). Hose (30) has a biasing spring (36) that extends along its full length, and can comprise single or multiple springs and/or multiple diameter spring coils. Spring (36) is covered with hose cover material (32) on the outside and hose cover material (34) on the inside to form a sealed hose and are bowed inward or outward radially between the individual spring coils depending on the intended use of hose (30) to give the cover materials room to move out of the way when the hose retracts and the coils of spring (36) are forced close together. The Linearly Retractable Hose is operated by changing internal pressure within the hose relative to the ambient pressure on the exterior of the hose. Control of fluid pressure within hose (30) is what allows the hose to operate as an automatically extendable and retractable hose. The biasing of spring (36) depends on the type of use for the hose.

Abstract: A control device for a shower head assembly includes is engaged with an inlet of the shower head and includes a tubular body which has a central piece located at a center thereof. A plurality of plates are connected between the central piece and an inner periphery of the tubular body. A flexible ring is mounted to the central piece such that a path is defined between the inner periphery of the tubular body and an outer periphery of the flexible ring. The flexible ring is expanded by water pressure to narrow the size of the path so that the maximum volume of the water can be controlled.

Abstract: A flow regulator (10) having a regulator housing (1) which is provided with a control device (8a) having a central body (3a) in a passage channel (2). An annular throttle body (4a) produced from an elastic material bounds the central body (3a) and defines a control gap (6a) between the throttle body (4a) and an adjacent peripheral surface (5a) that is provided with control recesses (7a) that are oriented in a flow direction (Pf1, Pf2). The passage cross-section of the control gap can be varied by the throttle body which is deformed by the pressure difference caused during throughflow. In the present flow regulator (10), there are two control devices (8a, 8b) arranged one behind the other the longitudinal direction of the passage channel (2), with the two control devices (8a, 8b) being configured for different throughputs and/or pressure ranges.

Abstract: An apparatus and method for emptying and filling a fluid container. A flow-actuated valve inside a fill tube regulates the flow through the fill tube. A cap containing the valve and a vent tube can be installed on a modified bottle used to supply water dispensers, thus enabling a user to continuously replenish the bottle from a remote supply. Alternatively, a cap containing the valve, a vent tube, and two fluid level sensors can be installed on a conventional bottle. A user is thus relieved of the burden of repetitive bottle changing, and is able to treat the water to his own specifications.

Abstract: An annular elastomer is provided in a housing orifice that does not require a large force for deformation. This makes possible a solenoid-type actuator that provides a large displacement of the elastomer, thus allowing higher and lower rates of gas flow through a gas line.

Abstract: In a fluid transmission line, a valve comprising a housing that establishes a lumen for transmission of a fluid through said valve; a drive mechanism and a drive gear mounted in said housing to be selectively driven in a first or second rotational direction by said drive mechanism. The drive gear has a central throughhole and a plurality of pins around the central throughhole. A plurality of leaves are pivotally mounted on the pins, and oriented to extend radially inward into said central throughhole. A fixed extension has an annular aspect disposed in the drive gear, and has a plurality of engagement members disposed to operatively engage one of said leaves. The engagement members bias the leaves to close an orifice when said drive gear rotates in said first direction and to open the orifice when said drive gear rotates in said second direction. Each of the leaves maintains a substantially sealing engagement with each adjacent leaf throughout a range of motion of the leaves.