WO1999051898A1

WO1999051898A1 - Single lever mixing and flow rate control valve

Info

Publication number: WO1999051898A1
Application number: PCT/NZ1999/000041
Authority: WO
Inventors: Raymond Stewart Atwill
Original assignee: R & K Developments Limited
Priority date: 1998-04-02
Filing date: 1999-04-01
Publication date: 1999-10-14
Also published as: AU3541099A

Abstract

The mixing valve includes a spindle (11), bearing surface (22), shaft (14), cam (21), second plate (35) and two flow control valves (16, 17 and 16', 17'). Movement by a handle of the spindle (11) axially to the device causes end (12) to bias against the bearing surface (22), displacing shaft (14) along the axis of the device. This causes axial displacement of the second plate (35) which engages the flow control means shafts (16, 16'), displacing flow control means (17, 17') towards or away from the apertures (27, 27') in unison thereby controlling the volume flow of mixed fluid. Rotating the spindle (11) rotates housing (13) and body (24), and thereby cam plate (21). As cam plate (21) is rotated the cam surfaces on the underside of plate (21) engage the control means shafts (16, 16') thereby moving the flow control means (17, 17') in an independent manner and adjusting the mixing ratio of one fluid to another. The valve may be incorporated into a cartridge. Hot and cold water flow may be kept separate.

Description

SINGLE LEVER MIXING AND FLOW RATE CONTROL VALVE

Field Of The Invention

The present invention relates to mechanisms for the control and mixing of fluids. More particularly, although not exclusively, the present invention relates to an improved water mixer of a type, which is particularly suited for use with a single handle control.

Background To The Invention

A particular characteristic of many hot water supplies used in New Zealand, as well as a number of other countries, is that the hot water is supplied locally on the premises at a pressure which can be significantly less than that of the cold water supply. Using certain known types of mixing devices, this can lead to difficulties where the higher-pressure cold water hampers the flow of the hot water. This can lead to long 'warm up' times for mixed temperature water supplies. Also, the desired fluid temperature may only be available at a low volume due to the differing pressures.

This problem is particularly noticeable in the context of baths, showers or tubs. In these situations, it is highly desirable to have a high volume of hot water supplied at an even pressure, which is both virtually instant and is not affected by mixing with cold water.

Previous solutions to this problem have included quite complex arrangements of valves, valve seats, and fixed-ratio hot/cold fluid mixing systems. These have met with mixed success. A further factor has been the rapid rise in popularity of single handle control systems as opposed to the more traditional two-tap type of arrangement. In the context of single handle tap control systems, prior art mechanisms of this type include constructions that use what is known as a 'twin-jumper' system. Such a system uses a pair of plungers or flow control means, each shaped to seat against a cold or hot water inlet aperture. The plungers are generally cone-shaped having different (usually opposite) orientations and tapers. In operation, the amount of insertion of the plungers (or flow control means) into the hot or cold fluid entry apertures defines an annular aperture through which the respective fluid may flow. As the hot and cold flow control means move in concert, the ratio of cold to hot water admitted through the annular apertures is proportional to the plunger insertion. Therefore, for a particular mixed net fluid flow rate, the ratio of hot to cold water remains fixed. Such a system is described in New Zealand Patent No. 183598.

While being suitable in certain situations, such a design only allows a fixed fluid flow rate at any single ratio of hot to cold water. It would be an advantage if the ratio of hot to cold water could be varied at the same time as the net fluid flow rate.

It is an object of the present invention to provide an improved mixing device for fluids which overcomes or at least ameliorates some of the abovementioned disadvantages. It is a further object of the invention to provide an improved mixing device which allows the ratio of two fluid volumes to be varied prior to their mixing without requiring adjustment of the net mixed fluid flow rate. It is a further object of the invention to provide the public with a useful choice.

Disclosure Of The Invention

In one aspect the invention provides an improved fluid mixer including: at least two input flow paths in flow communication with a mixing volume or outlet, the two flow paths incorporating apertures adapted to receive a corresponding flow control means, wherein the flow control means are shaped and oriented so that they can be inserted or otherwise biased against a corresponding aperture to seal the aperture; and actuating means adapted so that when the actuating means is rotated in a first direction, in a plane substantially perpendicular to the direction of displacement of the flow control means, the relative separation between each of the flow control means and its corresponding aperture varies, and when the actuating means is displaced in a second direction, substantially parallel to the direction of displacement of the flow control means, the flow control means move in unison.

Preferably, the flow control means are in the form of a valve that, seals a corresponding aperture when the valve is biased against the aperture, the biasing effected by means of a flow control means shaft engaged with the actuating means.

In a preferred configuration, each input flow path directs fluid into a corresponding first volume through a corresponding aperture, each volume having an outlet leading to a mixing volume or spout wherein each first volume has an aperture which allows the flow control means shaft to penetrate therethrough.

Each flow control means shaft may be operated by a cam plate, the cam plate being connected to the actuating means, so that, as the actuating means, and thus the cam plate, is rotated in a first direction, the flow control means shafts are displaced into, or out of, the corresponding first volumes by differing amounts.

The actuating means may be further adapted to displace the second plate along the axis of the device, thereby moving the shafts of the flow control means in unison.

Alternatively, the actuating means may additionally engage with a second plate located between the cam plate and the flow control means, the second plate incorporating apertures to permit the shafts of the flow control means to penetrate the second plate and thereby engage with the cam plate, whereby bearing collars are located on the flow control means shafts, so that movement of the actuating means in the second direction moves the second plate in the second direction so that when it engages with the bearing collars the flow control means are displaced in a second direction in unison.

The combined action of rotation of the cam plate, in the first direction, and displacement of the second plate in the second direction, allows the flow control means to be displaced either independently or in unison.

Preferably, the cam plate is in the form of a housing having a cam surface traversing the perimeter of the plate in such a way that, as the cam plate is rotated in the first direction, the cam surface acts to displace the flow control means shafts, in contact with the surface, by varying amounts.

Preferably, the actuating means includes: a body with a spindle located at a first end thereof and a cam plate recess at a second end thereof; a shaft passing through an aperture in the body, the shaft having a bearing plate at a first end which is in mechanical contact with an end of the spindle, and a second end, passing through an aperture in the cam plate, in mechanical contact with the second plate, the shaft being constrained so that movement of the spindle in the second direction displaces the bearing surface and thus the second plate in the second direction, and whereby rotating the spindle in the first direction rotates the cam plate which displaces the flow control means thus allowing the net mixed flow volume to be varied by said movement of the spindle in the first direction as well as varying the relative flow volumes admitted through the apertures by movement of the spindle in the second direction.

Preferably, the second plate is biased towards the second end of the shaft.

Preferably, the flow control means are biased away from the apertures. In an alternative embodiment the flow control means and actuating means may be incorporated into a cartridge wherein the spindle extends from a first end of the cartridge and the flow control means extended from a second end of the cartridge such that the flow control means are shaped and orientated so that they can be inserted or otherwise biased against corresponding apertures to seal the apertures.

In this alternative embodiment the bearing collars are tips included at distal ends of the flow control means shafts and are adapted to allow engagement of the flow control means shafts with the cam plate and the second plate.

In a further embodiment the mixing volume may be omitted and the input flow paths traverse the flow control means and apertures and exit the mixing device separately.

In this embodiment, each of the flow control means and associated aperture is located at different positions along an axis of the mixing device so as to facilitate isolation of the fluids and their transmission to the split spout.

In the above disclosure the spindle may be a handle spindle wherein a handle or other operating means is attached thereto, allowing single handle control of the fluid mixer.

Similarly, the mixing volumes may be cavities through which the fluid passes.

Brief Description Of The Drawings

The invention will now be described by way of example only and with reference to the drawings in which:

Figure 1 : illustrates a cross-sectional view through a mixing unit in the closed position; Figure 2: illustrates a cross-sectional view through a mixing device in the fully opened position;

Figure 3: illustrates a cross-sectional view through a mixing device with a flow control means completely sealing a fluid input flow path and another flow control means open fully; and

Figure 4: illustrates a split-spout embodiment of the improved mixing device with both flow control means closed.

Figure 5: illustrates a cross-section view through a cartridge embodiment of the actuating means and flow control means.

Figure 6: illustrates an exploded view of a cartridge embodiment of the actuating means and flow control means.

The invention will be described in the context of mixing hot and cold water. This description is not intended to be limiting and it is envisaged that other fluids or gases could be mixed using an improved mixing device constructed according to the invention.

Referring to Figure 1 , a cross-sectional view through an exemplary embodiment of the invention is shown. Two input flow paths 26 and 19 are shown entering the improved mixing device from below. This flow orientation is particularly suitable for bench or sink mounted taps/mixers. This configuration also assists in reducing the pumping pressure through the device. When used as a shower mixer, the input flow paths could be oriented otherwise. Each of the input flow paths transmits fluid through an aperture 27 and 27' to a corresponding volume 29 and 29'. Once the fluid has entered this volume the two fluids are mixed as the volumes 29 and 29' are in flow communication either by means of a mixing sleeve or similar. The mixed fluid may be diverted through a mixing volume or mixing jacket or simply exits the mixing device via a channel 18 in the spout 25. In the configuration shown in Figure 1 , each of the apertures 27, 27' has a flow control means biased against it. Sealing may be aided using O-rings 37. The flow control device, in the preferred embodiment corresponds to a disk and shaft construction 17/17' and 16/16' respectively. The disk may be a standard tap- sealing valve mounted on a shaft. Each flow control device 16, 17 and 16', 17' seals the input flow paths aided by an O-ring, which seals against the lip of an input aperture 27, 27' .

It has been found that even with repeated sealing/unsealing actions, the integrity of the seal is preserved.

A critical part of the invention is the mechanism by which the flow control means are controlled - the actuating means.

Referring to Figures 1 to 4, the independent, yet coupled, operation of the flow control means is described.

The spindle 1 1 may have attached thereto a longer arm which forms a handle. In the following discussion, the movement of the spindle 1 1 will be referred to as being in a first direction (i.e. rotationally around the axis of the body of the device, caused by rotation of the handle attached to the spindle) and in a second direction (i.e. in a direction corresponding to raising and lowering of the handle attached to the spindle 1 1 ).

Referring to Figure 1 , the flow control means are controlled by an actuating means which includes a body 24, a spindle 1 1 , a shaft 14 and bearing surface 22, a cam plate 21 and a second plate 35.

The body 24 has a first end that has mounted thereon a spindle 1 1 . The spindle is mounted at the end of the body and pivots at an intermediate point on the spindle 1 1 by means of a hinge 23. Rotating the spindle causes the end 12 of the spindle 1 1 to bias against the bearing surface 22 of the housing 13 of the shaft 14. The lower end of the spindle may be curved (not shown) to aid in its' smooth mechanical interaction with the bearing surface 22.

The shaft 14 passes through an aperture in the body 24 to a second end where it passes through the cam plate 21 and engages with the second plate 35. This is more clearly seen in figures 2 and 3 where equivalent numerals indicate equivalent components.

As the shaft 14 is displaced along the axis of the device (i.e. movement in a second direction), the second plate 35 causes the flow control means to be displaced toward or away from the apertures. As the second plate 35 is depressed, its lower surface engages with bearing collars 5 mounted on the flow control means shafts16,16'. The second plate includes apertures 36 that allow the shafts 16,16' to pass therethough and engage with the underside of the cam plate 21 . The displacement of the shaft and, hence second plate and flow control means, is therefore actuated by depressing or raising a handle attached to the spindle 1 1.

Such an action allows the user to vary the total volume of the mixed fluid through the device without significantly affecting the ratio of one fluid to the other.

However, as can be seen from Figures 2 and 3, if the cam plate 21 is rotated in a first direction, the relative positions of the flow control means is varied. Referring to Figure 2, a situation is shown whereby both flow control means are lifted (or biased by means of springs) off the apertures. The rotational position of the cam plate is such that the flow control means are at the same axial displacement and thus the same volume of fluid will be admitted through both apertures. In this position the upper ends of the shafts 16,16' rest either against the thinnest part of the cam plate or against the upper undersurface of the lower (or second) end of the body 24.

As the cam plate 21 is rotated, the cam surfaces on the underside of the plate 21 cause the left flow control means 16 to be depressed to a point where it seals against the aperture. This occurs while the right jumper is either kept at the same level. The actual motion of the flow control means is a matter of selection of the cam surface shape. This may vary depending on the anticipated characteristics of the water supply and other factors. While the flow control means are at this position, or at any intermediate position, the handle attached to the spindle 1 1 may be raised or depressed. This has the effect of lifting or lowering the flow control means, via the second plate and the springs 37 and 38, thus providing a net flow volume control which is independent of the relative volume flowing past the apertures.

Of course the specific dimension of the flow control means and their axial displacement will be selected to provide the required degree of control. The applicant's present embodiment has been constructed so that a quarter turn effects a full transition from hot to cold.

In an alternative embodiment, the actuating means may be adapted to omit the second plate and the mechanism is modified to both rotate and depress the cam plate. This embodiment is to be considered within the scope of the invention.

The casing 30 surrounding the body 24 may be in a number of configurations, as may the cap member 31 .

As is common in the industry, the actual cosmetic appearance of the device may vary depending on the particular design or style of the device. However, it is envisaged that the mixing control mechanism is capable of adaptation to many situations and designs.

In order to facilitate this adaptation the mixing control mechanism may be incorporated into a cartridge. Figures 5 and 6 show the mixing control mechanism in cartridge form. In this embodiment the spindle 1 1 , bearing surface 22, shaft 14, body 24, cam 21 , second plate 35 and each flow control device 1 6, 1 7 and 1 6', 17' are incorporated into a cartridge 1 24. The bearing collars 5 are tips 1 16, 1 1 6' included at distal ends of the flow control means shafts 1 6, 1 6' and are 10 adapted to allow engagement of the flow control means shafts 1 6, 1 6' with the cam plate 21 and the second plate 35. The cartridge is fitted into the mixing device so that the valves 17, 17' correspond to the input apertures 27, 27' of the mixer input flow paths 26 and 19.

It is envisaged that, in hot water supply situations, the device can handle boiling water as well as liquids at lower temperatures. Extremes of temperature are a known potential problem with existing tapware that includes ceramic mixing cartridges.

The improved mixer of the present invention is simple to use with full flow being effected by lifting the handle attached to the spindle fully upward. Turning or twisting the handle attached to the spindle allows effective and accurate temperature control. A further advantage is that the temperature of the mixed fluid may be selected before opening the tap.

The present invention may also find application in situations where the fluids are to be completely isolated from one another until they exit from the fluid delivery device. This is usually intended to produce an absolute maximum flow rate. In some constructions the higher water pressure can dominate the lower pressure. It is envisaged that the construction shown in Figure 4 will dispense with the need for backflow prevention. As can be seen, the two fluid input paths are isolated within the mixing device and exit at separate outlet ports. This is effected by positioning the aperture and corresponding flow control means along the axis of the device so that a split exit sleeve can be used to transport the fluid from the device to the spout. The split spout receives the fluid as shown and fluid mixing is prevented until the fluid exits from the end of the spout.

As can be seen from the Figures, both the flow control means and the second plate are biased so that there is no binding or sticking in their relative movement.

The second plate must be held against the lower end of the shaft 14 and the flow control means must be held against the cam surface or at the lower face of the 1 1 second plate by means of the bearing collars 5 in order for the required displacements to be used.

The internal and external dimensions may, of course, be varied depending on the particular situation in which the invention is to be used. The novel construction also lends itself to ready access to components which might wear and the O-rings and other sealing units (including the flow control means themselves) may be easily replaced or adjusted.

A further advantage is that the invention requires no filtration mechanism when used to supply potable water.

Thus the present invention provides an independently adjustable mixing or non- mixing control device which is particularly suited for use in water supplies having a pressure bias. The device uses available materials and, in some cases, componentry, which is readily available and it is envisaged that the devices will be competitive to manufacture. Further, the invention may include replaceable seats.

Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.

Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements may be made without departing from the scope of the appended claims.

Claims

12WHAT WE CLAIM IS:

1 . An improved fluid mixer including: at least two input flow paths in flow communication with a mixing volume or outlet, the two flow paths incorporating apertures adapted to receive a corresponding flow control means, wherein the flow control means are shaped and oriented so that they can be inserted or otherwise biased against a corresponding aperture to seal the aperture; and actuating means adapted so that when the actuating means is rotated in a first direction, in a plane substantially perpendicular to the direction of displacement of the flow control means, the relative separation between each of the flow control means and its corresponding aperture varies, and when the actuating means is displaced in a second direction, substantially parallel to the direction of displacement of the flow control means, the flow control means move in unison.

2. An improved fluid mixer as claimed in claim 1 wherein the flow control means is in the form of a valve that seals a corresponding aperture, when the valve is biased against the aperture the biasing effected by means of a flow control means shaft engaged with the actuating means.

3. An improved fluid mixer according to claim 2 wherein each input flow path directs fluid into a corresponding first volume through a corresponding aperture, each volume having an outlet leading to a mixing volume or spout wherein each first volume has an aperture which allows the flow control means shaft to penetrate therethrough.

An improved fluid mixer according to claim 1 wherein the flow control means shaft operates a cam plate, the cam plate being connected to the actuating means, so that, as the actuating means, and thus the cam plate. 13 is rotated in a first direction, the flow control means shafts are displaced by differing amounts.

5. An improved fluid mixer as claimed in claim 4 wherein each flow control means shaft is displaced into, or out of, the corresponding first volumes.

6. An improved fluid mixer as claimed in claim 4 wherein the actuating means is further adapted to displace the second plate along the axis of the device, thereby moving the shafts of the flow control means in unison.

7. An improved fluid mixer as claimed in any of claims 4 to 6 wherein the actuating means engages with a second plate located between the cam plate and the flow control means, the second plate incorporating apertures to permit the two shafts of the flow control means to penetrate the second plate and thereby engage with the cam plate, whereby engagement means are located on the flow control means shafts, so that movement of the actuating means in a second direction moves the second plate in the second direction, wherein the second plate engages with said engagement means and thereby displaces the flow control means in the second direction in unison.

8. An improved fluid mixer as claimed in claim 7 wherein the engagement means are in the form of bearing collars which are located on the flow control means shafts.

9. An improved fluid mixer as claimed in any one of claims 4 to 8 wherein the combined action of rotating the cam plate, in the first direction, and displacement of the second plate in the second direction, allows the flow control means to be displaced either independently or in unison.

10. An improved fluid mixer as claimed in any one of claims 4 to 9 wherein the cam plate is in the form of a housing having a cam surface traversing the perimeter of the plate in such a way that, as the cam plate is rotated the 14 cam surface acts to displace the flow control means shafts, in contact with the surface, by varying amounts.

1 1 . An improved fluid mixer as claimed in any previous claim wherein the actuating means includes: a body with a spindle located at a first end thereof and a cam plate recess at a second end thereof; a shaft passing through an aperture in the body, the shaft having a bearing plate at a first end which is in mechanical contact with an end of the spindle, and a second end, passing through an aperture in the cam plate, in mechanical contact with the second plate, the shaft being constrained so that movement of the spindle in the second direction displaces the bearing surface and thus the second plate in the second direction, and whereby rotating the spindle in the first direction rotates the cam plate which displaces the flow control means thus allowing the net mixed flow volume to be varied by said movement of the spindle in the first direction as well as varying the relative flow volumes admitted through the apertures by movement of the spindle in the second direction.

1 2. An actuating means as claimed in claim 1 1 wherein the second plate is biased towards the second end of the shaft

1 3. An actuating means as claimed in claims 1 1 or 1 2 wherein the flow control means are biased away from the apertures.

14. An actuating means as claimed in any previous claim wherein the spindle is a handle spindle such that a handle or other operating means is attached thereto, allowing single handed control of the fluid mixer.

1 5. An improved fluid mixer as claimed in any previous claim wherein the flow control means and actuating means are incorporated into a cartridge wherein the spindle extends from a first end of the cartridge and the flow 15 control means extended from a second end of the cartridge such that the flow control means are shaped and orientated so that they can be inserted or otherwise biased against corresponding apertures to seal the apertures.

1 6. An improved fluid mixer as claimed in claim 8 wherein the bearing collars are tips included at distal ends of the flow control means shafts and are adapted to allow engagement of the flow control means shafts with the cam plate and the second plate.

17. An improved fluid mixer as claimed in any previous claim wherein the mixing volume is omitted and the input flow paths traverse the flow control means and apertures and exit the mixing device separately.

1 8. An improved fluid mixer as claimed in claim 1 6 and claim 1 7 wherein each of the flow control means and associated aperture is located at different positions along an axis of the mixing device to facilitate isolation of the fluids and their transmission to the split spout.

19. An improved fluid mixer as claimed in any one of claims 1 to 16 wherein the mixing volumes are cavities through which the fluid passes.