WO2007112532A1

WO2007112532A1 - Valve for a fluid flow control system

Info

Publication number: WO2007112532A1
Application number: PCT/CA2006/000524
Authority: WO
Inventors: Michael Jon Mitton; Marshall James Douglas Mclean; Viorel Grosu
Original assignee: Mitton Valve Technology Inc.
Priority date: 2006-04-05
Filing date: 2006-04-05
Publication date: 2007-10-11

Abstract

A cylindrical rotary valve adapted as a diverter valve to control or affect fluid flow. The diverter valve has at least two distinct sectors, each with a separate output fed from a separate groove on the valve shaft. The valve has a single input with internal branching to make distinct input connections to the chamber in which the valve shaft rests. The conduits are designed according to the immediate disclosure so as to maintain at least one of the input-output pairs in a partially open position with respect to its conduit at any shaft rotation. Alternatively, the diverter valve is a cylindrical valve with at least one intake and more than one exit, in which the valve shaft rotates between a first position in which the input communicates with one or more exit stream defined by the valve shaft and a second position in which the input communicates with two or more exit streams defined by the valve shaft.

Description

VALVE FOR A FLUID FLOW CONTROL SYSTEM

FIELD OF THE INVENTION

[0001] The present invention relates to a rotary valve, valve train or valve canister for use in fluid flow control system, possibly a water jet control system, where each pressurized fluid stream from a pump must be diverted through a set of possible outputs. Such valve trains or valve canisters find use in hot tub hydro massagers and in fountains, but may also have broader application in industrial processes.

BACKGROUND OF THE INVENTION [0002] Valves are an integral part of any water flow control system. In hydro massage apparatus, such as whirlpool style bathtubs (also called hot tubs, or referred to by the popular brand name Jacuzzi™) valves may be used and are often used in each step of the flow from intake, to filtration, to pump, to or between possible outputs and to control the amount of air inserted into the forced water stream.

[0003] A number of inventions have attempted to address various aspects of the problem of diverting water through a sequence of outputs. However, a number of problems continue to arise in the earlier designs.

[0004] Where such systems are employed in a hot tub hydro massager apparatus, the flow schematics have the water pass axially through one or more holes or bores in a rotary disc during such times as the holes or bores line up with various output paths.

[0005] This existing design has resulted in a number of problems associated with the use of water pulses in hydro massage applications. Foremost, the rotary disc is under pressure from the impacting input fluid leading to increased friction against the plate supporting the output channels. This friction causes uneven wear between the outer rim and central portion of the rotary disc and the corresponding sections of the valve housing in contact with the rotary disc. [0006] The problem of properly sealing the valve is complicated by the uneven plate surface wear. The overall result is that the rotary disc valve mechanism is prone to failure, and frequently needs replacement. The device disclosed in US Patent No. 5,548,845 to Bloemer et al., for instance, practised in the Kohler™ line of whirlpool baths, requires replacement canisters to regularly replace the quickly worn disc valve components. [0007] Furthermore, valve designs in the existing art have limited applications and present certain design limitations. Often, only one output sequence of several sequentially selected outputs may be operated at any one time, either with a forward or reverse flow.

[0008] In the field of decorative fountains, conventional flow control systems often employ poppet type valves triggered in a timed sequence. These systems tend to be costly because of the number of parts required to implement these systems and the relatively high failure rates of their component parts.

[0009] In certain applications, it may be desirable to create a predictable pulse sequence in fluid flow to generate therapeutic or decorative effects. [0010] Valve systems in the existing art are prone to substantial noise created by these valves when they generate pulses in the fluid flow. This noise effect associated with many earlier pulse mechanisms is known colloquially as water hammering. This noise effect interferes with the users' enjoyment of the devices in certain applications, such as in hot tub hydro massagers. [0011] Various embodiments of the present invention may provide one or more solutions to certain problems associated with the prior art systems, or other advantages, which will become apparent upon a review of the present specification.

SUMMARY OF THE INVENTION [0012] The invention is a diverter valve comprising a valve housing and a valve shaft. The valve shaft rotates within a chamber of the valve housing about a common axis. The chamber defines a volume substantially the same as the volume of rotation formed by the valve shaft. The chamber may be formed as a bore, pipe, mould, cast or a variety of means suitable for creating a close fit with the valve shaft. The valve housing defines at least one intake and two or more possible exit streams. In rotating, the valve shaft rotates between a first position and a second position. In the first position, the intake communicates with at least one exit stream defined by the valve shaft. In the second position, the intake communicates with at least two exit streams defined by the valve shaft. The valve shaft may rotate through a cycle of movement from a first position to a second position and from a second position to a first position at least twice in one full rotation. The number of repetitions of the cycle may be equal to the number of exit streams.

[0013] The intake may be thought of broadly to include any possible shape of fluid input path, opening or port into the valve. Each exit stream is a fluid pathway from the intake through the valve housing to the chamber (possibly a cylindrical bore), along a channel or conduit in the surface of the valve shaft, and from the chamber through the valve housing to an outlet. The outlets may be nozzles, openings, output paths or ports.

[0014] Certain embodiments of this invention comprise a rotary cylindrical valve train with a shaft having radial grooves, at least one input and multiple outputs. The valve housing and valve shaft are notionally divided into sectors or formed from linked segments so that each sector or segment represents a portion of the valve housing serviced by the corresponding portion of the valve shaft within the valve train. The valve shaft defines a longitudinal axis. [0015] Without loss of generality, reference is made to the operational regions of the shaft and housing as sectors, even though in a given embodiment the devices may be composed of segments, with one or more segments forming a sector.

[0016] In certain embodiments intended for a given water flow control application, the valve housing is of a fixed design, with at least one valve input channel. Within the valve housing, the valve input channel branches into cylinder input channels. Typically, the cylinder input channels all have substantially the same cross sectional area and terminate in cylinder input ports on the inner surface of a longitudinal cylindrical chamber in the valve housing. The cylinder input ports, in part, define the sectors of the valve. Cylinder input ports at the same longitudinal position (along the axis are positioned at distinct radial locations) are on the same cylindrical sector, but cylinder input ports at other distinct longitudinal positions along the longitudinal axis define other cylindrical sectors within the valve train.

[0017] At least one output channel, corresponding to each cylindrical sector, connects a valve output port on the outer surface of the valve housing to a cylinder output port on the inner surface of the longitudinal chamber for fluid communication.

[0018] A cylindrical valve shaft is fitted for the longitudinal chamber, having radial conduits (for example, grooves or channels in the radial surface of the valve shaft) of predetermined widths, depths and arcuate lengths, with at least one conduit corresponding to each cylindrical sector of the valve shaft. As the valve shaft rotates within the valve housing, the conduit on a particular sector of the valve shaft brings the output channels on the corresponding sector of the valve housing into fluid communication with at least one of the input channels on the sector, during the fluid flow phase. [0019] The conduits themselves may be configured in a variety of shapes, such that they are open to the surface of the valve shaft.

[0020] In another embodiment of the present invention, conduits positioned in accordance with one aspect of the invention may simulate pulsing of the fluid at each outlet channel without creating a significant back pressure, or significant in pressure drop, when the fluid enters the input channel.

[0021] Within a second embodiment of the invention, a first cylindrical valve shaft with a first configuration of conduits may be replaced with an interchangeable second valve cylinder having a second configuration of conduits such that in a single rotation, the water flow generated at the valve outputs produces a different pattern or output sequence.

[0022] A diverter valve of the present invention may be configured as an interchangeable valve canister based on the predetermined locations of the valve input channel and output channels, for use as replacement parts in existing tubs.

[0023] The calibrated inputs and outputs through the valve housing limit pressure losses or pressure spikes which may lead to additional wear on the diverter valve. The diverter valve rotates in the housing with equal relative motion between the surface of the cylinder and the internal wall of the housing, resulting in less wear in the valve components.

[0024] The pulse effect may be further controlled by manipulating rotation of the single valve shaft. [0025] Where the surface of the valve shaft is self-lubricating or incorporates low friction materials (e.g. Teflon™) and there is either no substantial risk of leakage or the production tolerances are stringent, the diverter valve may be assembled from as few as 2 pieces, namely, a rotating valve shaft and corresponding housing. The resulting diverter valve is simple to manufacture, undergoes even wear, is simple to control, and has robust design characteristics that may be adapted for use in various applications. Changes to the preferred fluid flow path and flow rates at each output channel (in relation to input pressure) may be achieved by replacing the valve shaft with another valve shaft suitable for use with the housing component. [0026] Positioning of the grooves or conduits on each valve shaft allows for all possible output sequences to be selected by simply replacing a first valve shaft with a second valve shaft. The number of possible outputs varies as a function of the length of the valve shaft and not the radius, which allows for greater variety at only a moderately increased cost. A one piece valve housing with replaceable valve shafts may provide many alternative fluid flow timing sequences, which may be modelled as sequences of predictable output fluid flow for different configurations of valve output ports. These output flow sequences will have various industrial applications, and may also be used for therapeutic, massage effects or for decorative, fluid effects in a fountain or other decorative device. [0027] Certain embodiments of the present invention address pressure loss and noise generation at the valve, and create improved transitions between outputs to minimize pressure loss and alleviate water hammering. By choosing desired conduit cross sectional areas and the shapes of the conduit edges precisely based on the cylinder input channel cross sectional area, embodiments of the current invention may be created to exhibit substantially reduced pressure loss or reduced variation in input flow rates. These are important advantages in low noise applications - for example, hot tub pulse mechanisms. Many known valve systems are considerably louder than the pulse mechanism created using the embodiment of the present invention.

[0028] Many other embodiments of the invention will be apparent to persons skilled in the art upon reading the specification herein, including the following detailed description and drawings of preferred embodiments of the present invention.

DESCRIPTION

[0029] In one aspect, the invention includes a rotary valve housing with a cylindrical chamber adapted to receive a valve shaft, at least one valve input channel in fluid communication with the cylindrical chamber, and a number of output channels in fluid communication with the cylindrical chamber that may be selected for fluid communication with the valve input channel by rotating the valve shaft.

[0030] An important optional feature of the valve housing is the splitting of the valve input channel, when in fluid communication with the outer surface of the valve housing, into a number of cylinder input channels, each in fluid communication with a longitudinal cylindrical chamber within the valve housing.

[0031] The features and flow characteristics of the valve shaft may be varied. The position and configuration (width, arc length and depth) of radial grooves in the surface of the valve shaft where the conduits align cylinder input ports with cylinder output ports may be varied to provide desired fluid flow characteristics. In some embodiments, the shape of the conduits at either end may be configured to achieve a particular effect, as further discussed in PCT Application No. PCT/CA2004/001999. Rotating the valve shaft may allow fluid communication between one or more of the output channels with the valve input channel in a sequence based on the position of the conduits. While the relative positions of the cylinder input ports and cylinder output ports remains the same within the valve housing, replacing the valve shaft with another valve shaft with different conduit configurations will lead to a different output sequence, allowing the operator to achieve variability and enhanced control of the output sequence of the diverter valve. [0032] The present invention also encompasses valve systems including replaceable and interchangeable components, including valve shafts.

[0033] In some embodiments, the same cylinder input channel may be used to feed two different output channels at different radial positions of the same conduit. Similarly, the same conduit may accommodate a number of different cylinder input ports along the path traversed by a full rotation of the valve shaft. Each notional sector of the valve defines the distinct paths traversed by a particular conduit.

[0034] The valve housing and the valve shaft of the present invention may also come in replaceable, interchangeable and detachable segments corresponding to the notional sectors discussed above. Where, the segments of a valve housing are meant to join together, the relative positions of the main input channel and the cylindrical chamber would remain the same. The cylinder inputs, cylinder outputs and valve outputs may vary between compatible segments. Similarly, the valve shaft itself may comprise detachable segments with different conduit arc length, width and leading and trailing edge configurations.

[0035] To achieve relatively constant input pressure to the valve and reduced water hammer effect during transitions between outputs, a user will often consider the following objectives when assembling the valve components. [0036] Figure 1 depicts a typical sector of a valve shown in a cross- sectional view. The valve housing 1001, is fitted with a cylindrical valve shaft 1002, rotating about axis of rotation 1003. A cylinder input 1004, and a cylinder output 1005, come into fluid communication through the fluid conduit 1006, when the cylindrical valve shaft 1002, is in a range of positions. [0037] At each valve housing sector, the relative location of the cylinder input port 1004 and the corresponding cylinder output port 1005, is represented by an angle a, which may be referred to as the angular separation of the input-output pair..

[0038] The valve shaft has a diameter of D. [0039] In one embodiment, for simplicity of design, the cylinder input channels and output channels are chosen to have the same shape, a circular opening of diameter d. The resulting ports have the shapes of circles projected onto a cylinder. The important dimensions of the cylinder input 1004, and the cylinder output 1005 are the lateral width (not shown) and the radial angular lengths represented by the angle φ_\ and the angle φ₂ respectively. The actual lengths are found by multiplying either φ_λ or φ₂ in degrees by Dτr/360. The conduits may be of varied width, but pressure loss through the valve may be reduced when the cross sectional area of the conduit taken perpendicular to the direction of fluid flow has the same cross sectional area as the cylinder input channel and the output channel, d 2Έ/4. AS the groove is a cut in the surface of a cylinder, various shapes can be imagined to achieve this goal. One option is a cut of width d and a straight edge depth dτr/8 with a semicircular portion at the base. However, pressure loss may also be mitigated by having the conduits no wider than the input channels and no narrower than the output ports. In such an optional configuration, the entire valve acts as a nozzle to increase flow rates without undue pressure loss due to the Venturi effect.

[0040] Each conduit 1006 has an angular length or arc length of θ, from tip to tip. The arc length as measured in linear distance is related to the arc length as measured in degrees by a factor of Dπ/360. In general, the conduits may have a variety of arc lengths, θ, so long as each conduit is long enough to meet the open angle α for the sector. The open duration of a particular input-output pair in a single rotation of the valve is an angle Ω , or the open angle, approximately equal to θ of the conduit minus α of the input-output pair on the same sector.

[0041] The port size is determined by flow requirements. This should be the basis of all designs as all timing and size restrictions of the valve will be determined by the port size. Port size may vary between sectors, but should be the same in a single sector. Having varying sizes within the same sector, or between different sectors in the same valve, complicates the flow rate calculations, and makes the goal of even input pressure difficult to achieve. Non- circular ports are easily calculated as all timing calculations will depend on the angular duration of the port as witnessed by a reference point on the shaft. Any port shape may be used once the angular duration has been determined. [0042] For circular ports the angular duration of the port is:

φ = 2 • arcsinCy_p>)

[0043] Port location determines timing of the open-close events, as well as the occurrence of "fully open" and "partially open" events during the open phase of the valve. The linear spacing of the ports along the valve shaft is determined only by the requirements of external fittings etc., and has no effect on valve performance. The angular position effects timing. If multiple input-output pairs on the same sector are located too close together, then a conduit could bridge more than one output simultaneously which would result in a pressure decrease. Multiple cylinder input ports may be bridged simultaneously with no ill effects on performance, and accordingly permits more flexibility in design of the input port locations and the conduit lengths. Input port angular location relative to output location is one of the main variables to determine valve timing. The closer to the output an input is located, the longer the open duration of the valve (for a fixed conduit length) and the greater the "fully open" time, as a percentage of the total "open" time of the valve cycle. Fully open is defined as both input and output ports being fully exposed by the conduit so there is no flow restriction.

[0044] The angle representing the duration of open state relative to a complete rotation is found with the following equation: Ω = θ- a [0045] The angle representing the duration of a "fully open" state relative to a complete rotation is defined as: η = θ - a - φ_ι - φ₂ . The diverter valve of the current invention operates such that at least one sector is always in the open position regardless of valve shaft orientation. Conduit lengths which satisfy this requirement are such that the sum of η for all conduits and for all sectors is greater than or equal to 360 degrees.

[0046] Placing input ports at 45 degrees from the vertical on either side and the output ports at 90 degrees from the vertical, making the output ports horizontally opposed, the resulting valve has design symmetry shown in Figures 8 and following. In such a design, 2 outputs could always be open using appropriately positioned conduits of at least 135 degrees in length (plus an angle φ calculated as noted above to account for the size of the ports themselves). In such a scenario, the input-output pairs are arranged in two banks, which perform a staggered sequence at the outputs. The shaft may easily be arranged such that one output channel is open on each bank at all times.

[0047] Valve shaft size is a limiting restriction on decreasing the overall size of the diverter valve. The valve shaft size is determined by the port size and location. However, unlike other pulse systems, the number of outputs is proportional to the length and not the diameter of the shaft, and so increasing the number of outputs is simplified without an inordinate increase in overall size. In practise, the valve shaft must be large enough to accommodate ports defining chords of the length d and therefore angular length φ.

[0048] The valve shaft length is determined only by port spacing and number of sectors. Length of the valve shaft or location of ports along the valve shaft has no effect on valve function. However, high pressure applications may require the addition of special seals between sectors within the cylindrical chamber or between linked segments of the housing or shaft.

[0049] Conduits in the valve shaft are the elements of the design most easily configured so the size and relative locations of the conduits may be calibrated to allow for precise timing. The number of conduits may be equal to the number of sectors. Since the valve shaft is easily replaced, different valve shafts may be used for different diversion or pulse mechanism effects. The duration of flow may be longer at some outputs than others. In hydro massage applications, changing the valve shaft alone would result in a different massage effect. This is an important aspect of the immediate invention.

[0050] A simple example illustrates how to set the shaft for equal duration pulses sequentially at the output ports of N sectors. The first conduit parameter to calculate is the separation. That is the angular distance from one conduit to the next as the shaft rotates. This is easily determined by simply dividing 360 degrees by the number of conduits.

360

[0051] So: S =

N [0052] Thus, for four conduits there should be ninety degrees between the beginning of each conduit. This means that every 90 degrees of rotation an output will open on each bank, so that each output, on each bank, will open once per revolution of the valve shaft.

[0053] The next parameter to determine is the conduit length. The conduit length is chosen so that each output begins to close at the same instant that the next output on the same bank begins to open. The next output on the bank will begin to open δ degrees of shaft rotation after the reference output is opened.

However the "open" state is not necessarily realized when the conduit reaches the output. It is realized when the conduit bridges both the output and matching input.

Thus the conduit length is equal to the open duration plus the angular distance between the input and output ports plus the port duration.

[0054] In the case of a bank of input-output pairs to be opened for the same duration, a possible conduit arc length is θ = δ + a + φ_f /2 + φ₂ /2. One benefit of this particular choice of conduit length is that only one exit stream in a given bank is fully open for a given valve shaft position, and where the valve shaft position is such that one exit stream is transitioning to a closed state, another exit stream is transitioning to an open state.

[0055] If the cylinder input port and cylinder output port diameters are different then there should also be a compensation in the conduit size, as the next conduit should align with the beginning of the input port (beginning of open state) at the same time the trailing edge of the reference conduit arrives at the leading edge of the output port (beginning of closed state). So long as both port diameters are equal, then additional compensation is not needed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a diagram indicating in cross-sectional view various configurable dimensions of a sector of the diverter valve of the present invention.

[0057] Figure 2 is an exploded view in perspective of an embodiment of the device of the present invention.

[0058] Figure 3 is a perspective view of the assembled valve of Figure 2.

[0059] Figures 4A and 4B show cross-sectional views along planes A-A and B-B of Figure 3, respectively, in which the input-output pair of the first sector is transitioning to an open state during clockwise rotation of the valve shaft. [0060] Figures 5A and 5B illustrate corresponding cross-sections to those of Figures 4A and 4B, respectively, after the valve shaft has rotated 90 degrees from the position shown in Figures 4A and 4B.

[0061] Figures 6A and 6B illustrate corresponding cross-sections to those of Figures 4A and 4B, respectively, after the valve shaft has rotated 180 degrees from the position shown in Figures 4A and 4B.

[0062] Figures 7A and 7B illustrate corresponding cross-sections to those of Figures 4A and 4B, respectively, after the valve shaft has rotated 270 degrees from the position shown in Figures 4A and 4B. [0063] Figure 8 is an exploded view in perspective of another embodiment of the device of the present invention.

[0064] Figure 9 is a perspective view of the assembled valve of Figure 8.

[0065] Figures 10A, 10B, 10C and 10D show cross-sectional views along planes A-A, B-B, C-C and D-D of Figure 9, respectively, in which a first input- output pair of the first sector (shown in Figure 10A) is on the verge of transitioning to an open state, during clockwise rotation of the shaft.

[0066] Figures 11A, 11B, 11C and 11 D illustrate corresponding cross- sections to those of Figures 10A, 10B, 10C and 10D, respectively, after the valve shaft has rotated clockwise approximately 11 degrees from the position of the valve shaft shown in Figures 10A, 10B, 10C and 10D.

[0067] Figures 12A, 12B, 12C and 12D illustrate corresponding cross- sections to those of Figures 10A, 10B, 10C and 10D, respectively, after the valve shaft has rotated 22.5 degrees from the position of the valve shaft shown in Figures 11 A, 11 B, 11C and 11 D.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1 : Diverter valve with one valve input, two valve outputs and 2 sectors

[0068] Figure 2 shows the exploded perspective view of the valve housing 1 , with valve shaft 2, configured to rotate inside the cylindrical chamber 5. The valve shaft defines an axis of rotation 7, which upon insertion of the valve shaft 2, into the cylindrical chamber 5, should be coincident with the longitudinal axis 6, of the chamber 5. The valve shaft and housing are notionally divided into cylindrical sectors. In this embodiment, the first cylindrical sector 10, is to the right of the second cylindrical sector 20. The input pathway of the valve is branched, and comprises a valve input port 3, on the exterior of the valve housing 1 , as an entrance to the valve input channel 4. The valve input channel 4, connects at a first internal cylinder input opening 11 , to the cylinder input channel 12, defining an intermittent fluid path corresponding to the first cylindrical sector 10, and to a second internal cylinder input opening 21 , to the cylinder input channel 22. Each of the first and second cylinder input channels 12 and 22 terminate in first and second cylinder input ports 13 and 23 respectively, which are openings into the cylindrical chamber 5. A variable fluid path is defined between the valve input port 3, and the cylindrical chamber s, branching into two input channels 12 and 22, up to at the cylinder inputs 13 and 23, such that the fluid path and the fluid flow across the path varies according to the orientation of the valve shaft 2.

[0069] According to the invention, the valve housing 1 , should have at least one output fluid path from the cylindrical chamber s, corresponding to each cylindrical sector of the shaft. In this instance, first output channel 15, runs from the first cylinder output port 14, to the first valve output port 16. Similarly, second output channel 25, runs from the second cylinder output port 24, to the first valve output port 26.

[0070] To accomplish fluid communication between valve input port 3, and one or both of the valve output ports 16 and 26, grooves are formed in the surface of the valve shaft, at least one groove per sector, to act as fluid conduits between the corresponding cylinder input ports and cylinder output ports on the corresponding shaft sectors. In the embodiment of Figure 2, a first fluid conduit 18, having a leading edge 17, and a trailing edge 19, is capable of bringing first cylinder input port 13, and first cylinder output port 14, into fluid communication when the valve shaft 2, is in an open position with respect to the first sector 10. Similarly, a second fluid conduit 28, having a leading edge 27, and a trailing edge 29, is capable of bringing first cylinder input port 23, and first cylinder output port 24, into fluid communication when the valve shaft 2, is in an open position with respect to the second sector 20. [0071] The edges 17, 19, 27, 29, of the conduits may be configured in a variety of shapes. Straighter edges may lead to a symmetry between the exposed and covered areas of the cylinder input ports and cylinder output ports of different sectors during operation. In the embodiment of Figure 1 , fluid conduit edges 17, 19, 27 and 29 are all roughly hemispherical cuts into a cylinder. The semi-circular edge shown may be effective at ensuring a substantially constant cross sectional area that is exposed to exit streams during a transition, and may also reduce turbulence in the flow.

[0072] Figure 3 shows a perspective view of the assembled device of Figure 2. Section lines A-A and B-B correspond to cross sections of the device taken along the plane perpendicular to the longitudinal axis of the device and bisecting the first and second valve output ports 15 and 25, respectively.

[0073] Figures 4A and 4B, show cross-sectional views along section lines

A-A and B-B of Figure 3, respectively. In Figure 4A, during clockwise rotation, the fluid pathway through the input-output pair of the first sector 18, is transitioning to an open state. At the same angular position as shown in Figure 4A, the fluid pathway through the input-output pair of the second sector 28, shown in the cross sectional view of Figure 4B, is transitioning to a closed state.

[0074] In Figure 4A, the label 31 denotes the angle oti being the angle between the middle of the first cylinder input port 13, the chamber axis of rotation 6, and the middle of the first cylinder output port 14. Taking into consideration the shape of the conduit ends 17 and 19, the cross sectional areas of the first cylinder input port 13, the first cylinder output port 14, and cross sectional area of the first conduit 18, the angle 31 , also represents the angular separation between the input-output pair 13:14 of the first sector 10. The label 32 denotes the angle φ, being the angular length of the first fluid conduit 18, measured between the outer edge of the clockwise conduit end 17, the shaft axis of rotation 7, and the outer edge of the counter clockwise conduit end 19. As in the embodiment shown, the conduit ends need not be straight edges. The label 32 denotes the angle θ/ being the arc length over which either of the cylinder input port 13, or the cylinder output port 14, are exposed to the conduit during full rotation of the valve shaft. As a ratio to a full rotation of 360 degrees, this angle 0_/ 32, also represents the ratio of each cycle during which either the cylinder input port 13, or the cylinder output port 14, is in an open state. Both the cylinder input port 13, and the cylinder output port 14, must be in the open state for the input-output pair of the first sector to be considered to be in an open state. The actual arc length of the conduit may deviate slightly from this angle as a result of the configuration of the conduit edges and the configuration of the ports. These configurations determine, in part, the flow characteristic during the transition phases. In the embodiment of Figure 4A, the shape of the cylinder input port 13, at the cylindrical chamber 5, is the projection of a circle in the tangent plane onto the cylinder. The cylinder input port 13, has an angular open duration of φι 35. Similarly, cylinder output port 14, has an angular open duration of φ₂ 36.

[0075] In Figure 4A, the valve shaft 2, has rotated into the position shown, and fluid communication exists along the input-output pair of the first sector. The flow of fluid through the valve at this position would be limited by the small area of the cross sectional opening between the cylinder input port 13, and the clockwise end 17, of the first conduit 18, which is a narrowing in the pathway. By contrast, the cylinder output port 14, is fully exposed to the first conduit 18, and is fully open.

[0076] In Figure 4B, the angle «233, represents the angle between the middle of the second cylinder input port 23, the chamber axis of rotation 6, and the second cylinder output port 24. The angle a₂ 33, has the corresponding significance for the second sector 20, as α/ 31 , has for the first sector 10. The angles a, and Ct₂ need not be equal, but in this instance they are each 90 degrees.

The angle θ₂ 34, represents the angular length of the second fluid conduit 28, measured between the clockwise conduit edge 27, the shaft axis of rotation 7, and the counter clockwise conduit edge 29. The angles θ_/ and θ₂, need not be equal.

In this instance θj is 270 degrees plus φi /2 plus φ₂ 12. Similarly, since cylinder input port 23, has open angular duration φ₃ 37, and since cylinder output port 24, has angular duration φ₄ 38, in the embodiment shown, the angle θ₂ is 270 degrees plus φ₃l2 plus φ₄l2. [0077] As discussed above, the difference between the angles labelled α and θ represents the duration per rotation that the respective input-output pairs are fully open, and the angles labelled φ provide additional length for the partially open states. In the embodiment shown, the input-output pair of the first sector is just opening as the input-output pair of the second sector is closing. At most, due to the configuration of the conduit edges, there is some overall loss in pressure during the transition from open to closed and closed to open, but this loss only strengthens the pulse action of the valve (i.e. the transitions involve a sharper drop in pressure at closing and a sharper rise in pressure at the open channel when the closing valve becomes fully closed).

[0078] Figures 5A and 5B, show rotation of the valve shaft another 90 degrees from Figures 4A and 4B, respectively. The input-output pair in the first sector is now fully open (as demonstrated by the thick line). In one preferred embodiment, the valve is designed so that in the fully open position, the cross sectional area of the entire exit stream from valve input to valve output is substantially uniform.

[0079] Similarly, Figures 6A and 6B and Figures 7A and 7B show the cross sections A-A and B-B after the shaft 2, has been rotated additional 90 degree increments. The half thickness lines show that during the transitional state in Figures 6A and 6B, there is some flow. The total aggregate minimum cross sectional area over both pathways in Figures 6A and 6B is slightly higher than if only one valve were to be entirely open. Where the valve is used on incompressible fluids, flow in equals flow out, and the valve provides momentarily less resistance to the flow at the valve input port 3. In most other pulse devices, the transition results in increased resistance at the valve input, an unfortunate mechanical result which creates a noisy water hammering effect. In Figure 7A, there is no flow in the first sector, so it is considered to be fully closed. In Figure 7B, there is flow through the input-output pair of the second sector, represented by the thick arrow. The input-output pair of the second sector is considered fully open in Figure 7B.

[0080] Functionally, the embodiment of Figures 2 through 7B operates between first positions (shown in Figures 5A and 5B and Figures 7A and 7B), in which one of the exit streams from the valve input port to a valve output port is open, and second positions (shown in Figures 4A and 4B and Figures 6A and 6B) in which two of the exit streams from the valve input port to both valve output ports are open.

Embodiment 2: Diverter valve with one valve input, eight valve outputs and 4 sectors

[0081] Figures 8 through 12 depict a particular preferred embodiment of the immediate invention, in which the valve housing 101 , and valve shaft 102, are notionally comprised of 4 sectors 110, 120, 130 and 140, and each sector further comprises a first and a second input-output pair. This embodiment illustrates in part the adaptability of the principles of this invention to systems requiring fluid diversion and/or fluid pulse control elements.

[0082] Figure 8 shows an exploded perspective view of an embodiment of the current invention, in which dotted lines represent hidden elements. The valve housing 101 , has a cylindrical chamber 105, with a longitudinal axis 106. A valve input port 103, on the exterior of the valve housing 101 , is the overall fluid input or intake to the valve and is the beginning of the valve input channel 104, which runs substantially along the cylindrical chamber 105, and branches to interconnect with 8 cylinder input ports 111, 114, 121 , 124, 131 , 134, 141 and 144. In the embodiment shown, the input ports and output ports are positioned in mirror symmetry about a plane of symmetry 108. The valve outputs corresponding to these cylinder inputs are shown as items 113, 116, 123, 126, 133, 136, 143 and 146 in Figure 8. As such, each of the first sector 110, second sector 120, third sector 130 and fourth sector 140 comprises a first input-output pair on one side of the plane of symmetry 108, and a second input-output pair on the other side of the plane of symmetry 108. All of the first input-output pairs form a first bank of outputs and all of the second input-output pairs form a second bank of outputs.

[0083] The valve shaft 102, defines an axis of rotation 107, such that when inserted into the cylindrical chamber 105, the axis of rotation 107, or the valve shaft 102, substantially coincides with the longitudinal axis 106, of the cylindrical chamber 105. The first, second, third and fourth sectors of the valve shaft shown enclose the regions of the valve shaft interacting with the corresponding sectors of the valve housing.

[0084] Figure 9 shows the assembled device in perspective, with sections lines A-A through cylinder inputs 111 and 114, cylinder outputs 112 and 115, conduit 118 and perpendicular to both axis of rotation 106 and 107, in the first sector 110, of the valve. Similarly, section lines B-B, C-C and D-D, pass through the input-output pairs of the second sector 120, the third sector 130, and the fourth sector 140, respectively.

[0085] Each of the four sectors in the embodiment of Figures 8 through 12 covers a first side input-output pair and a second side input-output pair. Depending on the orientation of the valve shaft 102, a fluid path through the valve may exist: i. from the valve input port 103, along the input channel 104, to the first side cylinder input port 111 , of the first sector 110, through the first fluid conduit 118, of the valve shaft 102, and out the first side cylinder output port 112, to the first side valve output port 113; ii. from the valve input port 103, along the input channel 104, to the second side cylinder input port 114, of the first sector 110, through the first fluid conduit 118, of the valve shaft 102, and out the second side cylinder output port 115, to the second side valve output port 116; iii. from the valve input port 103, along the input channel 104, to the first side cylinder input port 121 , of the second sector 120, through the first fluid conduit 128, of the valve shaft 102, and out the first side cylinder output port 122, to the first side valve output port 123; iv. from the valve input port 103, along the input channel 104, to the second side cylinder input port 124, of the second sector 120, through the first fluid conduit 128, of the valve shaft 102, and out the second side cylinder output port 125, to the second side valve output port 126; v. from the valve input port 103, along the input channel 104, to the first side cylinder input port 131 , of the third sector 130, through the first fluid conduit 138, of the valve shaft 102, and out the first side cylinder output port 132, to the first side valve output port 133; vi. from the valve input port 103, along the input channel 104, to the second side cylinder input port 134, of the third sector 130, through the first fluid conduit 138, of the valve shaft 102, and out the second side cylinder output port 135, to the second side valve output port 136 vii. from the valve input port 103, along the input channel 104, to the first side cylinder input port 141 , of the fourth sector 140, through the first fluid conduit 148, of the valve shaft 102, and out the first side cylinder output port 142, to the first side valve output port 143; or viii. from the valve input port 103, along the input channel 104, to the second side cylinder input port 144, of the fourth sector 140, through the first fluid conduit 128, of the valve shaft 102, and out the second side cylinder output port 145, to the second side valve output port 146.

[0086] As labelled in Figures 8 and 10A, 10B, 10C and 10D, during clockwise rotation of the valve shaft 102, the fluid conduits 118, 128, 138 and 148, or sectors 110, 120, 130 and 140 have leading edges 117, 127, 137 and 147 and trailing edges 119, 129, 139, and 149, respectively. These leading edges 117, 127, 137 and 147 and trailing edges 119, 129, 139, and 149, may have special configurations. In the embodiment of the valve shown, the configurations of the leading edges 117, 127, 137 and 147 and the trailing edges 119, 129, 139, and 149, are all rounded cuts of equal radius labelled 150, equal to half the width of the conduits. System design is flexible enough to accommodate various configurations of conduits.

[0087] Figures 10A 10B, 10C and 10D, show the cross-sections for a particular orientation of the valve shaft 102. From Figure 10A, it is apparent that the clockwise conduit end 117, is just coming into fluid communication with the cylinder input port 111 , assuming clockwise rotation, and so on the first bank of the valve, the first sector input-output pair is opening. In this transition state, depicted in Figure 11 A, fluid flow may be restricted due to the narrowing at the cylinder input port 111 , and this restricted flow is indicated by the half width flow line. Figure 1OB shows a configuration in which full flow, through the first bank input-output pair of the second sector 120, from cylinder input port 121 to cylinder output port 122 is possible. This fluid path is just entering the closing transition state. Figure 1OC also shows full flow, but in the second bank of the third sector 130, from cylinder input port 134 to cylinder output port 135. Figure 10D shows that both the first and second banks of the fourth sector are closing.

[0088] Figures 10A, 10B, 10C and 10D also show the relevant design parameters of the input-output pair locations, and the conduit lengths.

[0089] Figure 10A shows 151 , as the angle between the middle of first side cylinder input port 111 , the chamber axis 106 and the middle of first side cylinder output port 112, which by the symmetry of design in this embodiment about plane of symmetry 108, is also the angle between the second side cylinder input port 114, the chamber axis 106 and the second side cylinder output port 115. The angle 152 is the angle between conduit leading edge 117, the shaft axis of rotation 107, and conduit trailing edge 119, during clockwise rotation. In this embodiment, all the ports are designed with the same channel radius, so the angular duration of all the ports are all equal to the angle 150. The angles 150, 151 and 152 may be labelled φ, ct_A, Θ_A is accordance with the parameters used in the discussion of valve design above. [0090] Similarly: Figure 10B shows angles or_β 153, (between 121 :106:122 and between 124:106:125 by symmetry) and angle Θ_B 154 (between 127:107:129); Figure 10C shows angles α_c 155, (between 131 :106:132 and between 134:106:135 by symmetry) and angle θ_c 156 (between 137:107:139); and Figure 10D shows angles α_D 157, (between 141 :106:142 and between 144:106:145 by symmetry) and angle Θ_D 158 (between 147:107:149).

[0091] These angles determine, in part, to the angular length within a complete rotation of the valve shaft, that the input-output pairs are in the open position. It would be apparent to someone of skill in the art to select conduit locations and conduit angles Θ_A, Θ_B, θ_c and θ_f) to ensure that one or more exit streams from the valve input port to a valve output port is open at all times, and that during a transition, both the opening and closing exit stream are at least partially open.

[0092] Figures 11 A, 11 B, 11C and 11 D illustrate the corresponding cross sectional end views of the sectors to those in Figures 10A, 10B, 10C and 10D after the shaft has been turned approximately 11 degrees clockwise from the position in Figures 10A, 10B, 10C, and 10D. Figures 11A and 11B demonstrate that as the input-output pair 104:113 of first bank of the the first sector in Figure 11A opens, the input-output pair 104:123 of the first bank of the second sector in Figure 11 B closes, and there is a narrowing at the conduit which restricts overall flow as indicated by the half weight flow line (labelled/). As shown, both input-output pairs 104:116, 104:126 in the second bank of the first and second sectors are closed. Figure 11C shows that the input-output pair 104:136 in the second bank of the third sector is in a fully open position as indicated by the full weight flow line (labelled F) while the input-output pair 104:133 in the first bank is closed. The full weight flow line F represents the least possible impedance to flow in the sector. Figure 11 D shows that both input-output pairs 104:143, 104:146 of the first and second bank in the fourth sector are closed in this orientation. In this state of this embodiment of the invention, there is unrestricted flow out the third valve output 136 in the second bank, shown in Figure 11C. This valve output 136 experiences only minimal loss of pressure during the short phase when both the first valve output 113 in Figure 11A, and the second valve output 123 in Figure 11 B, both in the first bank, are partially open. Because flow is never entirely restricted, the water hammer effect is reduced.

[0093] Figures 12A, 12B, 12C and 12D illustrate the corresponding cross sectional end views of the sectors to those in Figures 10A, 10B, 10C and 10D after the shaft has been turned approximately another 22.5 degrees clockwise from the position in Figures 11 A, 11 B, 11 C, and 11 D. In this view, it is apparent that on the first bank, only the input-output pair 104:113 of the first sector is open as indicated by the full weight flow line F in Figure 12A, and on the second bank, only the input-output pair 104:136 of the third sector is open as indicated by the full weight flow line F in Figure 12C. It is also apparent that during a full rotation of the valve shaft in the valve housing, the first bank follows a cycle of: i. an exit stream through the fourth sector 143 of the first bank exists and is fully open, ii. exit streams through the fourth 143 and third sectors 133 of the first bank exist and are partially open, iii. an exit stream through the third sector 133 of the first bank exists and is fully open, iv. exit streams through the third 133 and second 123 sectors of the first bank exist and are partially open, v. an exit stream through the second sector 123 of the first bank exists and is fully open, vi. exit streams through the second 123 and first sectors 113 of the first bank exist and are partially open, vii. an exit stream through the first sector 113 of the first bank exists and is fully open, and viii. exit streams through the first 113 and fourth sectors 143 of the first bank exist and are partially open.

[0094] Instances L, iii, v, and vii of the cycle above are a type of first position in which at least one exit stream from the valve input 104 to a valve output 113, 123, 133, 143 defined by the valve shaft exists. Instances ii., iv, vi, and viii of the cycle above are a type of second position in which at least two exit streams from the valve input 104 to a valve output 113, 123, 133, 143 defined by the valve shaft exist. [0095] Similarly, the second bank follows the same cycle with a predetermined delay.

[0096] According to another embodiment of the current invention, the order in which each valve become open, or transitions to an open state, may be varied by substituting an interchangeable valve shaft with a different configuration of conduits. Using the valve housing of the current invention, the valve shaft shown may by substituted with an interchangeable valve shaft whose groove/conduit positions have a different configuration and any number of possible output sequences may be created during a rotation. Alternatively, the valve may be used by fixing the relative rotation position of the shaft so that one or more outputs are open at the same time.

[0097] Valves designed according to the current invention require specification of the valve shaft configuration size (length, radius, relative groove locations, relative groove configuration) in relation to the valve housing configuration (relative port locations, shapes and sizes),. Other design criteria may be varied to suit intended manufacturing processes, materials, or environment (such as sealing technique, bearings, materials etc). A person of skill in the art would be aware of known sealing rings for use with rotary valves.

[0098] Preferentially, the valve body also has, integrated into its structure, supports for the valve shaft to control deflection along the valve shaft so as to either maintain a consistent leak resistant seal at the port seals or to minimize friction as the valve rotates depending on whether deflection is allowed or prevented. In a preferred embodiment, the valve shaft may be designed to rotate within the valve body on wear resistant materials. For example, such a design could be used to avoid metal to metal contact, or other contact between wear- prone materials. Circumferential seals on the cylindrical valve shaft and port seals surrounding the intake port and output port region on the valve body may provide leak prevention and also act as bearings for the diverter valve shaft as it rotates within the valve body. Alternatively, a tightly fitting valve may be coated with, or created from, a self lubricating or self sealing material. [0099] It will be appreciated that the above description relates to the preferred embodiments by way of example only. Many variations in the apparatus and methods of the invention will be clear to those knowledgeable in the field, and such variations are within the scope of the invention as described and claimed, whether or not expressly described. It is clear to a person knowledgeable in the field that alternatives to these arrangements exist and these arrangements are included in this invention.

Claims

CLAIMSWhat is claimed is:

1. A valve comprising

(a) a valve housing defining

(i) an elongated chamber defining a region of rotation about a longitudinal axis, and

(ii) at least one fluid intake;

(b) a valve shaft capable of rotation about an axis of rotation and between first positions and second positions;

(c) in each first position, the fluid intake communicates with one or more exit streams defined by the valve shaft; and

(d) in each second position, the fluid intake communicates with all exit streams of an immediately preceding first position and one or more additional exit streams defined by the valve shaft.

2. The valve of claim 1 in which rotation of the valve shaft defines a cycle of movement from a primary first position directly to a primary second position and from such primary second position directly to a secondary first position.

3. The valve of claim 2 in which the secondary first position is distinct from the primary first position

4. The valve of any one of claims 2 or 3 in which the cycle of movement is repeated two or more times per complete rotation of the valve shaft with the following first position being renamed as the current first position for each repetition of the cycle.

5. The valve of claim 4 in which the cycle of movement is repeated one more time per rotation than in the preceding claim.

6. The valve of any one of claims 1 , 2, 3, 4 or 5 in which the fluid intake comprises a valve input port on an outer surface of the valve housing.

7. The valve of any one of claims 1 , 2, 3, 4, 5 or 6 in which the valve shaft has substantially the same shape as the chamber

8. The valve of any one of claims 1 , 2, 3, 4, 5, 6 or 7 in which the chamber is a cylindrical chamber having a chamber radius, and the valve shaft is a cylindrical valve shaft having a shaft radius substantially equal to the chamber radius.

9. The valve of any one of claims 1 , 2, 3, 4, 5, 6, 7 or 8 in which the valve housing further defines at least two output channels, each output channel defining a separate output fluid communication path between a corresponding valve output port on an outer surface of the valve body and a cylinder output port on an internal surface of the cylindrical chamber.

10. The valve of claim 9 in which the cylinder output ports of at least two output channels define at least two distinct valve sectors.

11. The valve of any one of claims 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10 in which the valve housing further defines a valve input channel being a fluid communication path between the fluid intake and the chamber.

12. The valve of claim 11 in which the valve input channel communicates with the chamber through at least two cylinder input ports to the cylindrical chamber, each cylinder input port corresponding to a valve sector.

13. The valve of any one of claims 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 in which the valve shaft further defines two or more fluid conduits, each fluid conduit corresponding to a valve sector, and each fluid conduit capable of variably opening an exit stream through at least one cylinder input port and at least one cylinder output port in the corresponding valve sector

14. The valve of claim 13 in which the cylinder input port and cylinder output port through which an exit stream communicates may be defined as an input-output pair.

15. The valve of any one of claims 9 through 14, further comprising; (a) a first bank of valve outputs, one per sector, on a first side of a plane of symmetry through the axis of rotation;

(b) the output ports of the first bank being positioned a predetermined output location angle from the plane of symmetry;

(c) a second bank of four input-output pairs, one per sector, on the opposite side of the plane of symmetry from the first bank, in mirrored relation to the input-output pairs of the first bank.

16. The valve of claim 15, further comprising a third sector and a fourth sector.

17. The valve of claim 16 in which the first bank of valve outputs and the second back of valve outputs each have four corresponding input- output pairs, one per sector.

18. The valve of any one of claims 15, 16 or 17 in the input ports of the first bank are positioned at a predetermined input angle from the plane of symmetry, and the input ports of the second bank are positioned in mirrored relation to the input ports of the second bank.

19. The valve of claim 18 in which the predetermined input angle is zero and the input ports of the first bank are coincident with the input ports of the second bank.

20. The valve of any one of claims 13, 14, 15, 16, 17, 18 or 19 wherein the conduits are configured such that in a complete rotation of the valve shaft the valve undergoes eight cycles of movement.

21. The valve of any one of claims 14, 15, 16, 17, 18, 19 or 20 in which the cylinder input ports and cylinder output ports of each input-output pair are separated by a predetermined input-output pair angle between 1 degrees and 180 degrees.

22. The valve of claim 21 in which the predetermined input-output pair angle is between 30 degrees and 60 degrees.

23. The valve of any of claims 21 or 22, in which each conduit has an conduit angular length greater than the predetermined input-output pair angle.

24. The valve claimed in claim 22 wherein the predetermined input angle is 45 degrees, the predetermined output angle is 90 degrees, the input duration angle is 10 degrees, the output duration angle is 10 degrees and the arc length of the conduits is 145 degrees.

25. The valve claimed in claim 14, further comprising

(a) a natural number N greater than 2 of sectors;

(b) a first bank of N input-output pairs, one per sector,

(c) all cylinder input ports and cylinder output ports of the input- output pairs having a port duration angle measured relative to the longitudinal axis,

(d) a predetermined input-output pair angle measuring the angular separation between each cylinder input port and the corresponding cylinder output port of each input-output pair relative to the longitudinal axis;

(e) N fluid conduits, one per sector, each having an angular arc length measured relative to the axis of rotation greater than or equal to the sum of the port duration angle plus the predetermined input-output pair angle, and less than or equal to 360 degrees minus the port duration angle.

26. The valve claimed in claim 25 further comprising a second bank of N input-output pairs, one per sector, positioned with mirror symmetry to the first bank of N input-output pairs about a plane of symmetry through the axis of rotation.

27. The valve claimed in claim 25 wherein N is 4, the predetermined input- output pair angle is 45 degrees minus the port duration angle, each cylinder input port is 45 degrees minus half the port duration angle from the plane of symmetry, and the angular arc length of each fluid conduit is 135 degrees plus the port duration angle.

28. The valve of any one of claims 1 to 27, wherein

(a) the valve shaft is a first valve shaft having a first conduit configuration interchangeable with a second valve shaft having a second conduit configuration distinct from the first conduit configuration,

(b) the valve exhibits a first exit stream pattern defined by flow rates through each exit stream during a complete rotation of the first valve shaft;

(c) upon substituting the second valve shaft for the first valve shaft result, the valve exhibits a second exit stream pattern defined by flow rates through each exit stream during a complete rotation of the second valve shaft; and

(d) the first exit stream pattern is distinct from the second exit stream pattern.

29. The valve of any one of claims 10 to 28, in which one or more sectors of the valve shaft are linked shaft segments detachably interconnected to form the valve shaft.

30. The valve of any one of claims 10 to 29 in which one or more sectors of the valve housing are linked housing segments detachably interconnected to form the valve housing.