Patent Description:
Conventional valves generally require biasing devices to provide digital on and off control while providing low activation energy independent of inlet pressures with bistable on/off functions.

French patent application <CIT> discloses improvements to valves for compressed air distribution pipes, consisting in the arrangement of the sealing rings in the housings of the housing itself which, therefore, do not move with the piston, but remain fixed. and therefore are less prone to deformation and wear.

United States patent application <CIT> discloses a solenoid valve including a cylindrical sleeve which is formed with an input port, an output port, a drain port and a feedback port, and a spool which is inserted into the sleeve and which is formed with a plurality of lands for closing the individual ports. An input notch of the solenoid valve is formed in an end edge of the land located near the input port, while a drain notch is formed in an end edge of the land located near the drain port, and an axial height of the input notch and an axial height of the drain notch are set correspondingly.

United States patent application <CIT> relates to a spool type slide valve, employing one or more spools or lands, dependent upon the number of operations or devices to be controlled. The casing of the valve may be provided with annular grooves in which resilient O-rings are disposed for sealing and sliding contact with the spools in order to prevent leakage of fluid under pressure, past the spools from one side of the respective O-ring or rings to the opposite side.

<CIT> relates to a valve for controlling flow of fluids, the valve being operable by differential pressures on the sides of a diaphragm, whereby a large valve may be controlled by a small pilot valve.

Finally, United States patent application <CIT> consists in general in relieving the main valve diaphragm of the actual work of closing and opening the controlling valve, employing independent motor means for this purpose. The operation of such auxiliary motor means, which may be of any desired type, preferably pneumatic, is determined by the movements of the main valve diaphragm. For best results some lost motion is provided for between the main valve and the controlling devices for the auxiliary motor in order to permit proper timing of the various parts.

A valve assembly according to the invention has the features of claim <NUM>. Advantageous further developments are set forth in the dependent claims. The valve assembly comprises a housing which at least partially encloses at least one metering seal comprising a main channel, the main channel including regions with a first diameter and regions with at least a second diameter, where the first diameter is smaller than the second diameter. A stem is positioned in the metering seal extending from at least a first end of the metering seal to a second end of the metering seal. The stem comprises a fluted section positioned between two non-fluted sections, where the diameter of stem in the fluted section is smaller than the diameter of the stem in the non-fluted sections. A first and second flow channel extend across at least a partial width of the metering seal, where the first flow channel is positioned at the first end of the metering seal, and the second flow channel is positioned at the second end of the metering seal. An adjacent valve with a flexible diaphragm with an upper chamber and a lower chamber, wherein the upper chamber comprises a larger area than the lower chamber. At least one gap between the inner surface of metering seal and the outer surface of the stem, where the gap is configured and arranged to enable fluid to communicate from the lower chamber of the adjacent valve to the upper chamber of the adjacent valve to bring the pressure in the upper chamber up to the pressure in the lower chamber. The stem comprises a bistable state held in a position in the main channel by friction between an internal surface of the main channel comprising the first diameter and the metering seal.

Some embodiments include a first flow channel extending to and coupling with the main channel. In some embodiments, the second flow channel extend to and couples with the main channel. Some embodiments comprise a lower flow channel extending to and coupled to the first flow channel. Some embodiments further comprise an upper flow channel extending to and coupled to the second flow channel.

In some embodiments, the lower flow channel extends from at least one of a fluid supply and an adjacent valve, where the adjacent valve is configured to at least partially open and close to control passage of fluid to the lower flow channel.

In some embodiments, the upper flow channel extends from at least one of a fluid supply and an adjacent valve, where the adjacent valve is configured to at least partially open and close to control passage of fluid to the upper flow channel. In some embodiments, at least a portion of one or more of the non-fluted sections comprises a diameter dimensioned to couple with the metering seal in the main channel in regions that comprise the second diameter.

Some embodiments include at least a partial seal or fluid-tight seal that is formed by the coupling of the one or more of the non-fluted sections coupling with the metering seal in the main channel in regions that comprise the second diameter.

In some embodiments, the stem is positioned in the main channel so that at least a portion of the fluted section is coupled with or proximate a region of the main channel comprising the second dimeter. In some embodiments, the stem is positioned in the main channel as an arrangement with at least a portion of the fluted section being at least one of coupled with, proximate to and fluidly coupled to the second flow channel, the arrangement configured to enable fluid flow between the main channel and the second flow channel.

In some embodiments, the stem is positioned in the main channel as an arrangement with at least a portion of the non-fluted section being at least one of coupled with, and proximate to the second flow channel, where the arrangement is configured to at least partially prevent fluid flow between the main channel and the second flow channel.

In some embodiments, the stem is positioned in the main channel as an arrangement with at least a portion of the fluted section being at least one of coupled with, proximate to, and fluidly coupled to the second flow channel, where the arrangement is configured to enable fluid flow out of the main channel adjacent the second end of the metering seal.

In some embodiments, the position of the stem enables a fluid coupling of the first and second flow channels and the main channel.

Some embodiments include an an assembly comprising a valve assembly comprising a flow control side and a metering side, where the flow control side comprises valve separating a lower chamber and an upper chamber, and the valve is configured and arranged to control fluid flow between the flow control side and the metering side. In some embodiments, the metering side comprises a metering seal comprising a main channel, where the main channel includes regions with a first diameter and regions with at least a second diameter, and where the first diameter is smaller than the second diameter.

Some embodiments include a stem positioned in the metering seal extending from at least a first end of the metering seal to a second end of the metering seal, where the stem comprises a fluted section positioned between two non-fluted sections, and where the diameter of stem in the fluted section is smaller than the diameter of the stem in the non-fluted sections.

In some embodiments, the first and second flow channels extending across at least a partial width of the metering seal, and the first flow channel is positioned at the first end of the metering seal, and the second flow channel positioned at the second end of the metering seal.

Some embodiments comprise a lower flow channel extending to and coupled to the first flow channel, and an upper flow channel extending to and coupled to the second flow channel, where the first and second flow channels extend to and couple with the main channel.

Some embodiments comprise a lower flow channel extending between the flow control side and the metering side and coupled to the first flow channel, and an upper flow channel extending between the flow control side and the metering side and coupled to the second flow channel.

Some embodiments comprise at least one gap between the inner surface of metering seal and the outer surface of the stem, where the gap is configured and arranged to enable fluid to communicate between the lower chamber and the upper chamber via the metering seal.

Some embodiments include a valve stem control method comprising providing at least one metering seal and stem assembly, where the at least one metering seal and stem assembly comprising a plurality' of sealing zones. Some embodiments provide a balanced fluidic pressure to the at least one metering seal and stem assembly, where the fluidic pressure is substantially balanced to substantially cancel a force acting and/or inducing momentum of at least a portion of the stem assembly.

Some embodiments not covered by the appended claims include a valve stem control method comprising providing at least one metering seal and stem assembly, where the at least one metering seal and stem assembly comprising a plurality of sealing zones. Some embodiments provide a balanced fluidic pressure to the at least one metering seal and stem assembly, where the fluidic pressure is substantially balanced to substantially cancel a force acting and/or inducing momentum of at least a portion of the stem assembly.

In some embodiments, the plurality of sealing zones comprises three sealing zones of the at least one metering seal. In some embodiments, the plurality of sealing zones enables at least one of an on function or position of a valve and an off function or position of a valve. In some embodiments, the stem comprises a bistable condition when exposed to two equal and opposite fluid forces at the on and off functions or positions, where the bistable condition enables a digital selection of the on function or position of a valve and/or the off function or position of a valve.

Some embodiments include an on function or position, the plurality of sealing zones comprises a middle zone with two zones at each end, the two zones being exposed to atmospheric pressure, wherein a seal of the middle zone is closed, and an upper seal zone of the two zones is opened to depressurize. In some embodiments, with an off function or position, the stem is moved so that a middle zone of the plurality of zones is open and the two zones are sealed closed.

Some embodiments not covered by the appended claims include a fluid control method comprising providing a fluted stem positioned in a metering seal, where the fluted stem is positioned in the metering seal to substantially cancel two equal and opposite fluid forces fluid forces acting on generally opposite ends of the metering stem. Further, by positioning and dimensioning the stem to form a fluidically sealed middle zone enabling a digital selection of the on function or position and/or the off function or position of the valve. In some embodiments, the bistable on/off condition is produced solely as a result of the two equal and opposite fluid forces.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention as defined by the appended claims. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention as defined by the appended claims.

Some embodiments of the invention provide a valve capable of relatively high flow rates at relatively low pressures. Some embodiments provide a valve capable of bistable on/off conditions without relying on bias devices, which simplifies the mechanism. Further, some embodiments include a low activation valve which is substantially independent of inlet pressures. For example, <FIG> shows a perspective view of a valve assembly <NUM> in accordance with some embodiments of the invention. In some embodiments, the valve assembly <NUM> comprises a valve cap <NUM> including at least one aperture <NUM>. Further, in some embodiments, the valve assembly <NUM> can comprise a coupled valve body <NUM> including a fluid inlet <NUM>. In some embodiments, the valve assembly <NUM> can comprise a fluid outlet body <NUM> including a fluid outlet <NUM>. Some embodiments include structure couplings or elements <NUM>, <NUM> adjacent or coupled to a housing <NUM> at least partially enclosing a metering seal <NUM> (shown in <FIG>, <FIG>, <FIG>, and <FIG>).

<FIG> shows a cross-section of the valve assembly <NUM> of <FIG> in a closed position according to one embodiment of the invention. <FIG> depicts an enlarged cross-sectional view of a portion of the valve assembly <NUM> of <FIG> according to some embodiments of the invention. As illustrated, some embodiments include a valve assembly architecture that is divided into two different sides, the flow control side (shown as 175a), and the metering side (shown as 175b). In some embodiments, at least a portion of the valve assembly architecture of the valve assembly <NUM>, including the flow control side 175a, and/or the metering side 175b can be coupled or integrated into the valve assembly <NUM> to control one or more functions of the valve assembly <NUM> (e.g., such as turning a valve of the valve assembly on and off).

Referring to <FIG>, according to the invention, the flow control side 175a includes a valve <NUM> with flexible diaphragm <NUM> with its upper chamber A2 (marked as 180b) and lower chamber A1 (marked as 180a) (see <FIG>). The upper chamber 180b comprises a larger area than the lower chamber 180a. In this instance, when it is pressurized to a pressure equal to the inlet pressure of the lower chamber 180a, the net force on the diaphragm <NUM> can push the diaphragm <NUM> down to a closed position.

In some embodiments, the both upper chamber 180b and lower chamber 180a can be in fluid communication with the metering side 175b. For example, in some embodiments, both the upper chamber 180b and lower chamber 180a are in communication with the metering side 175b through fluid channels. In some embodiments of the invention, the metering side 175b can comprise two main components, a stem <NUM> with different zones and flutes corresponding to three different sealing zones, zone <NUM>, zone <NUM>, and zone <NUM> of the metering seal 175b. In some embodiments, the lower chamber 180a can be coupled to the metering side 175b at a location between the sealing zone <NUM> and zone <NUM> via a flow channel (<NUM>). In some embodiments, the upper chamber 180b can be coupled to the metering side 175b at the location between the sealing zone <NUM> and zone <NUM> via another flow channel (upper flow channel <NUM>).

According to the invention, a moveable stem <NUM> is positioned within the metering seal <NUM>, with the stem <NUM> extending between at least a first end 177a of the metering seal <NUM> and the second end 177b of the metering seal <NUM>. In some embodiments of the invention, the moveable stem <NUM> can be moved within the metering seal <NUM> (i.e., back and forth between at least the first end 177a and second end 177b of the metering seal <NUM>) to provide control over fluid flow between the flow control side 175a and the metering side 175b. <FIG> provide more details of structure of the moveable stem <NUM> and metering seal <NUM>. For example, <FIG> illustrates a metering seal <NUM> of the valve assembly <NUM> of <FIG> in accordance with some embodiments of the invention, and <FIG> illustrates a stem <NUM> of the metering seal <NUM> of <FIG> of the valve assembly <NUM> of <FIG> in accordance with some embodiments of the invention. Referring to the metering seal <NUM> of <FIG>, according to the invention, the metering seal <NUM> comprises a main channel <NUM> into which the stem <NUM> of <FIG> can reside or be inserted. In some embodiments, the main channel <NUM> can vary in diameter through at least a partial length of the metering seal <NUM>, where in some regions, the diameter of the stem <NUM> is approximate to the diameter of at least a portion of the metering seal <NUM> so that an at least partial fluid seal or fluid-tight seal can be formed while the stem <NUM> remains moveable within the metering seal <NUM>. Thus, in some embodiments, the diameter of the main channel <NUM> and the maximum diameter of any portion of the stem <NUM> are not so close that the stem <NUM> cannot be inserted into the metering seal <NUM>, and the stem <NUM> does not become immobile in the metering seal <NUM> or the main channel <NUM> of the metering seal <NUM>. For example, in one non-limiting embodiment, the metering seal <NUM> can comprise regions <NUM>, <NUM>, <NUM> where the diameter of the main channel <NUM> is narrower than regions <NUM>, <NUM>.

In some embodiments, the diameter (i.e., a first diameter) of the main channel <NUM> within at least a portion of regions of any two or more of the regions <NUM>, <NUM>, <NUM> can be the same or substantially the same. Further, the diameter (i.e., a second diameter) of the main channel <NUM> within at least a portion of regions of the regions <NUM>, <NUM> can be the same or substantially the same. Further, as illustrated, the first diameter (of the channel <NUM>) is smaller than the second diameter (of the channel <NUM>).

Further, according to the invention, the metering seal <NUM> comprises first and second channels that extend across at least a partial length of a diameter of the metering seal <NUM>. A first channel 188a at a first end 177a of the metering seal <NUM> (i.e., in the region of the zone <NUM>). A second channel 188b at a second end 177b of the metering seal <NUM> (i.e., in the region of the zone <NUM>). In some embodiments, either one or both of the first and second channels 188a, 188b can extend to and fluidly couple with the main channel <NUM> of the metering seal <NUM>.

Turning to <FIG>, the stem <NUM> can comprise a fluted section 129a between sections 129b, 129c extending to or proximate each end of the stem <NUM>. For example, the section 129c can extend from one end of the fluted section 129a towards the first end 190a of the stem <NUM>, and the section 129b can extend from the opposite end of the fluted section 129a towards a second end 190b of the stem <NUM>. In this instance, one or more of the sections 129b, 129c can comprise a diameter such that a partial fluid seal or fluid-tight seal can be formed with one or more of the narrower regions <NUM>, <NUM>, <NUM> of the metering seal. For example, in some embodiments, the stem <NUM> can be moved down in the main channel <NUM> (i.e. towards the end of the valve assembly <NUM> with fluid outlet body <NUM>) so that a sealing zone on the stem <NUM> comprising the section 129b can form a partial fluid seal or fluid-tight seal with region <NUM> of the metering seal <NUM> at the sealing zone <NUM> of the metering seal <NUM> to prevent fluid from bleeding to atmosphere and concurrently. In this instance, the fluted section (129a) of the stem (<NUM>) is at the sealing zone <NUM> of the metering seal <NUM> where the fluted section 129a is positioned within the region <NUM> of the metering seal <NUM>, providing a gap that can allow fluid to communicate from the lower chamber 180a to the upper chamber 180b (via lower flow channel <NUM> and upper flow channel <NUM>). This structure is represented in <FIG>, and in this instance, allows the valve assembly <NUM> to bring the pressure in the upper chamber 180b up to the pressure in the lower chamber 180a.

In reference to <FIG>, in some embodiments of the invention, a net force can be created due to the area difference between chamber 180b and 180a that can cause the diaphragm <NUM> to be pushed down to close the valve <NUM>. In some embodiments, fluid pressure can be applied on the stem at two generally opposite locations, one near the sealing zone <NUM> and one near the sealing zone <NUM>. Since the diameter of the stem <NUM> at zone <NUM> (section 129b of the stem <NUM>) is equal to diameter at zone <NUM> (section 129c of the stem <NUM>), the net force on the stem <NUM> due the fluid pressure can be substantially equal to zero. The only force on the stem <NUM> at this position can be frictional force with the metering seal <NUM> (e.g., through contact with one or more of regions <NUM>, <NUM>, and <NUM> of the metering seal <NUM>) to maintain this stem <NUM> position. Therefore, the frictional force is the only force required to move the stem from the off position to the on position.

<FIG> shows a cross-section of a valve in an open position according to one embodiment of the invention. Further, <FIG> depicts an enlarged view of a portion of the valve of <FIG> according to some embodiments of the invention, and <FIG> illustrates a partial cross-section of a portion of the metering seal with stem of <FIG> shown to provide clarity of the position of the stem <NUM> in the metering seal <NUM>.

In some embodiments of the invention, the stem <NUM> can be moved up so that its sealing zone is away from the sealing zone <NUM> of the metering seal <NUM>. In this instance, the fluted section ( 129a) on the stem can allow fluid in the upper chamber 180b to be bled out to atmosphere while another sealing zone on the stem is sealed off by the sealing zone <NUM>. This can cause the upper chamber 180b to be depressurized and cause a net force on the diaphragm <NUM> of valve <NUM> of the flow control side 175a. This can enable the diaphragm <NUM> of valve <NUM> to be forced away from the sealing surface <NUM>, and enabling fluid flow to take place (show as arrows toward fluid outlet body <NUM>.

In another embodiment not being covered by the claims of the invention, a valve can include only the metering side 175b such as shown in partial assembly <NUM> of <FIG> without using the flow control side 175a. In some embodiments, by enlarging the flow paths (such as upper and lower flow channels <NUM>, <NUM>), enough flow rate to be generated for the valve to operate satisfactorily. In some embodiments, both sides (upper and lower flow channels <NUM>, <NUM>) that feed into this valve embodiment can be connected to a common inlet of a fluid supply. In this instance, a balanced force and bistable condition is preserved, and the only force to overcome during the activation is frictional force between the stem <NUM> and metering seal <NUM>. In some embodiments, in the partial assembly <NUM> or assembly <NUM>, only low forces are needed to actuate the valve, enabling valve actuation to be powered by batteries, by solar power, or other low voltage and current sources.

Claim 1:
A valve assembly (<NUM>) comprising:
a housing (<NUM>), wherein the housing (<NUM>) at least partially encloses at least one metering seal (<NUM>);
wherein the at least one metering seal (<NUM>) comprises a main channel (<NUM>), the main channel (<NUM>) including regions (<NUM>, <NUM>, <NUM>) with a first diameter and regions (<NUM>, <NUM>) with at least a second diameter, the first diameter being smaller than the second diameter;
a stem (<NUM>) positioned in the at least one metering seal (<NUM>) extending from at least a first end (177a) of the at least one metering seal (<NUM>) to a second end (177b) of the at least one metering seal (<NUM>), the stem (<NUM>) comprising at least one fluted section (129a); and
first and second flow channels (188a, 188b) extending across at least a partial width of the at least one metering seal (<NUM>), the first flow channel (188a) positioned at or near the first end (177a) of the at least one metering seal (<NUM>), and the second flow channel (188b) positioned at or near the second end (177b) of the at least one metering seal (<NUM>);
an adjacent valve (<NUM>) with a flexible diaphragm (<NUM>) with an upper chamber (180b) and a lower chamber (180a), wherein, the upper chamber (180b) comprises a larger area than the lower chamber (180a);
at least one gap between the inner surface of the at least one metering seal (<NUM>) and the outer surface of the stem (<NUM>), the gap configured and arranged to enable fluid to communicate from the lower chamber (180a) of the adjacent valve (<NUM>) to the upper chamber (180b) of the adjacent valve (<NUM>) to bring the pressure in the upper chamber (180b) up to the pressure in the lower chamber (180a);
wherein the stem (<NUM>) comprises a bistable state held in a static position in the main channel (<NUM>) by friction between an internal surface of the main channel (<NUM>) comprising the first diameter and the stem (<NUM>).