GB2464687A

GB2464687A - Thermostatic mixer valve

Info

Publication number: GB2464687A
Application number: GB0819295A
Authority: GB
Inventors: Michael Wright
Original assignee: Pegler Ltd
Current assignee: Pegler Ltd
Priority date: 2008-10-21
Filing date: 2008-10-21
Publication date: 2010-04-28
Anticipated expiration: 2028-10-21
Also published as: GB2464687B; GB0819295D0

Abstract

A thermostatic mixer valve cartridge 100 comprises an outer body 110, a hot water inlet 111, a cold water inlet 112 and a mixing chamber body 120 moveable axially within the outer body. Hot water enters cartridge 100 via inlet 111 and flows along internal passageway 113 to mixing chamber 121 via aperture 125 along the inner surface of outer body 110. Cold water enters cartridge 100 via inlet 100 and flows along internal passageway 114 to mixing chamber 121 via aperture 126 along the inner surface of outer body 110. Entry of water into mixing chamber 121 is controlled by a cylindrical regulator 130 mounted upon a spring biased temperature sensitive expansion element 140. Expansion of the temperature sensitive element 140 results in axial motion of the regulator 130 to preferentially block aperture 125 more than aperture 126 reducing the relative inflow of hot water into mixing chamber 121. Compression of the temperature sensitive element 140 results in axial motion of the regulator 130 to preferentially block aperture 126 more than aperture 125 reducing the relative inflow of cold water into mixing chamber 121. Thus a desired water temperature can be maintained in mixing chamber 121.

Description

Thermostatic Mixer Valve with Increased Flow Rate The present invention relates to a thermostatic mixer valve adapted to provide an improved flow rate.

It is increasingly common for taps and showers to be controlled by a mixer valve enabling control of flow rate and independent automatic control of the flow temperature. Commonly such valves comprise a mixing chamber where water from separate hot and cold supplies can mix before flowing onward to an outlet. The relative proportions of hot and cold water entering the mixing chamber is determined by the position of a regulator. The regulator is movable in response to the expansion or contraction of a temperature sensitive element provided within the mixing chamber. The position of the expansion element and thus the position of the regulator may be user adjustable, typically by means of a rotary control.

The flow rate through the valve is controlled by controlling the flow rate of the hot and cold supplies prior to their entry to the mixing chamber. Typically a delivery regulator is provided operable to open or restrict the both hot and cold supplies equally. Examples of such valves are seen in W020041042488 wherein a rotary regulator device is provided that is coaxial with and rotatable about the mixing chamber having lateral openings that can be positioned away from or in total or partial * .** * I coincidence with passageways supplying hot and cold water to the mixing chamber *.. 20 and W02008/0 17760 wherein a pair of discs with holes provided therein may be

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mutually rotated such that the hole are positioned away from or in total or partial coincidence with passageways supplying hot and cold water to the mixing chamber.

Such arrangements are convenient to design and manufacture, are reliable and achieve excellent flow rates in cases wherein the hot and cold supplies are at sufficiently high pressures e.g. greater than 1.0 bar. In cases where the water supply is relatively low pressure e.g. around 0.1 to 0.2 bar as is often the case in the UK such valves struggle to achieve a sufficient throughput. In particular the TMV2 standards (relating to safe operation of Thermostatic Mixing Valves for general use in the UK) and the corresponding British Standards BS EN 1287 for low pressure and BS EN 1111 for high pressure require that a valve be capable of allowing a through flow rate of 15 litres per minute at 0.2 bar at 34-42°C for bath fill. Such prior art designs above typically only achieve a maximum of around 10 litres per minute in such circumstances.

It is therefore an object of the present invention to provide a thermostatic mixer valve which at least partially overcomes or alleviates the above problems.

According to a first aspect of the present invention there is provided a thermostatic mixer valve comprising: an outer body comprising: a hot water inlet; a *,,. cold water inlet; and art outlet valve seat; a mixing chamber body movable axially * .*S within the outer body comprising: a mixing chamber for receiving and mixing water S* *... 20 from said hot water and cold water inlets; a regulator movable with respect to the mixing chamber in response to variation of water temperature in the mixing chamber * *. * . * *** *

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to vary the proportions of hot and cold water received by the mixing chamber; and an outlet valve member wherein axial movement of the mixing chamber body within the outer body varies the position of the outlet valve member relative to the outlet valve seat.

The above provides a thermostatic mixer valve wherein the through flow rate can be controlled by restricting the outflow of mixed water from the mixing chamber.

It further enables greater waterway clearances throughout the valve design. As such, the valve may achieve a much higher through flow for lower pressure water supplies.

The valve may be in the overall form of a cylindrical cartridge. This can enable the valve to be easily fitted in a tap body or a shower body. It may also enable the valve to be fitted to a wide range of tap bodies with different appearances. The valve may be provided with a locater pin. The locater pin is preferably adapted to fit within a hole provided in the tap body thus allowing a fitter to ensure that the valve is correctly aligned with the hot and cold supplies to the tap body.

The outer body may comprise separate internal passageways for the passage of the hot and cold water supplies. The passageways may run from the inlets at one end of the outer body to apertures provided on the inner surface of the outer body. The S...

*.. : apertures may be aligned with the mixing chamber and thus facilitate passage of water S... *

from the inlets to the mixing chamber. The apertures for the hot arid cold supplies **** *,.. 20 may be axially displaced relative to one another. The cold water aperture is * S. * S S

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preferably displaced further towards the distal end of the valve relative to the hot and * cold inlets.

The apertures may take the form of a circumferential slot. The apertures may extend around a substantial proportion of the circumference of the inner surface.

Preferably, the apertures comprise a series of circumferential slots separated by struts.

The struts help maintain the structural integrity of the outer body.

The mixing chamber body may be provided with corresponding apertures to those in the outer body. The apertures in the mixing chamber body may extend around a substantial proportion of the circumference of the mixing chamber body.

Preferably, said apertures comprise a series of circumferential slots separated by struts. The struts help maintain the structural integrity of the mixing chamber body.

Corresponding threads may be provided on the inner surface of the outer body and the outer surface of the mixing chamber body. The corresponding threads enable the mixing chamber body to move axially relative to the outer body when rotated.

The thread may be a fast rising thread. In one preferred arrangement, rotation of the mixing chamber body by 90° moves the outlet valve member from a fully open position to a fully closed position. The mixing chamber body may further be *** provided with an engagable end portion. This may enable rotation of the mixing

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chamber body either directly by a user or indirectly by rotation of suitable external ** *5 engaging means.

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The regulator position within the mixing chamber may be controlled by a * temperature sensitive element. The temperature sensitive element may be operable to expand in response to an increase in temperature in the mixing chamber and contract in response to a decrease in temperature in the mixing chamber. The temperature sensitive element may be mounted along the central axis of the mixing chamber.

The temperature sensitive element may be spring biased. The temperature sensitive element may be provided with a compensation mechanism. The compensation mechanism ensures that expansionlcontraction of the sensing element is transmitted to the regulator and guards against overloading.

The axial position of the temperature sensitive element within the mixing chamber body may be determined by a retaining cap moveable axially relative to the mixing chamber body. The cap may provide a mount for the compensation mechanism. The cap may be connected with the mixing chamber body by a screw thread thus causing axial motion of the cap relative to the mixing chamber body when rotated. The cap may further be provided with an engagable end portion. This may enable rotation of the cap either directly by a user or indirectly by rotation of suitable external engaging means. This allows the mixed water temperature to be selectably controlled. a,., * . S. 4 * *0 * .

The regulator may be mounted directly on the temperature sensitive element.

* .. 20 The regulator may comprise an outer cylinder and a central mounting means. The * mounting means may be connected to the outer cylinder by one or more spokes or * S.

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vanes. The regulator may be formed from a suitable plastic, metal or other sufficiently robust material.

Water may exit the mixing chamber into an exit chamber. The exit chamber may be defined by the iimer walls of the outer body and may additionally comprise the outlet valve seat.

According to a second aspect of the present invention there is provided a mixer tap incorporating a thermostatic mixer valve according to the first aspect of the present invention.

According to a third aspect of the present invention there is provided a shower incorporating a thermostatic mixer valve according to the first aspect of the present invention.

The mixer tap of the second aspect of the present invention and or the shower of the third aspect of the present invention may incorporate any or all features of the present invention as are desired or are appropriate.

In order that the invention is more clearly understood, a number of embodiments will be described in detail, by way of example only, with reference to *: the accompanying drawings in which: *S.. * * * ,r.

Figure 1 is a cross-sectional view of a thermostatic mixer valve *** * * S..

according to the present invention in the closed position; * S. Sn S S.. -5.

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Figure 2 is a cross-sectional view of a thermostatic mixer valve according to the present invention in the open position; Figure 3 is a cutaway view of a thermostatic mixer valve according to the present invention in the closed position; Figure 4 is an exploded view of a thermostatic mixer valve according to the present invention; Figure 5 shows a cross-section of a mixer tap incorporating a thermostatic mixer valve according to the present invention.

Referring initially to figures 1-4, a thermostatic mixer valve 100 is provided in the form of a cylindrical cartridge that may be inserted into a mixer tap or shower control. The cartridge comprises an outer body 110 and a mixing chamber body 120 moveable axially within the outer body 110.

The outer body 110 is provided with a hot water inlet 111 and a cold water inlet 112. The cartridge 100 is provided with a locator pin 102 enabling it to be positioned with a particular orientation such that hot water and cold water are ultimately supplied to the correct inlets 111, 112. The hot water inlet 111 allows hot water to enter the cartridge 100 and subsequently flow along an internal passageway 113 to an aperture 115 provided upon the inner surface of the outer body 110. The cold water inlet 112 allows cold water to enter the cartridge 100 and subsequently *..

flow along an internal passageway 114 to an aperture 116 provided upon the inner surface of the outer body 110.

The outer body 110 further defines an exit chamber 117 incorporating water outlet 101 and an outlet valve seat 118. The outer body 110 also comprises a thread 119 provided on its inner surface.

The mixing chamber body 120 comprises a mixing chamber 121 for receiving water from said apertures 115, 116 via corresponding apertures 125, 126. Entry of water into the mixing chamber 121 is controlled by a cylindrical regulator 130 which is moveable axially relative to the mixing chamber body 120 and 145. 0-ring seals 151 and 152 prevent water from the passageways 113, 114 bypassing the regulator to mix in mixing chamber 121 or elsewhere.

The regulator 130 comprises an outer wall 131 connected via a plurality of vanes 132 to a mounting means 133. The regulator is mounted upon a temperature sensitive element 140 operable to expand in response to an increase in temperature in the mixing chamber 121 and contract in response to a decrease in temperature in the mixing chamber 121. *..* * *. S. * IS..

The temperature sensitive element 140 is mounted along the central axis of the mixing chamber 121 and is biased by spring 141 mounted between the mixing I...

chamber body 120 and the spring mount 142, being provided with holes 143 there .: : 20 through for the passage of water over the temperature sensitive element 140. The temperature sensitive element is also provided with a compensation spring 144 which ensures that expansion/contraction of the sensing element 140 is transmitted to the * regulator 130 and guards against overloading. The compensation spring 144 is provided within a spring housing 145 and a spring mount 146 held in position by retaining clip 171 within cap 160, the spring 144, housing 145 and mount 146 thus providing a compensation mechanism. The spring housing 145 has a threaded exterior 149 corresponding to a thread 169 on the cap 160 enabling axial movement of the spring housing 145 relative to the cap 160. This further provides adjustment for the mixed water temperature.

Expansion of the temperature sensitive element 140 results in compression of spring 141 and thus axial motion of the regulator in a downward direction (as shown in the attached drawings although the cartridge could of course be installed in alternative orientations). The regulator 130 thus preferentially blocks aperture 125 more than aperture 126 reducing the relative inflow of hot water into mixing chamber 121. Similarly compression of the temperature sensitive element 140 results in expansion of spring 141 and thus axial motion of the regulator in an upward direction (as shown in the attached drawings although the cartridge could of course be installed in alternative orientations). The regulator 130 thus preferentially blocks aperture 126 S...

** : more than aperture 125 reducing the relative inflow of cold water into mixing * I chamber 121. In this manner a desired water temperature can be maintained in the *S.S 1.1..: 20 mixing chamber 121.

: The desired temperature of the water n the mixing chamber 121 can be varied by varying the axial position of the temperature sensitive element 140 and regulator -10 -relative to the mixing chamber body 120. This can be achieved by rotation of * spindle 161 which is retained within cap 160 by corresponding threads 122, 162. The threads 149, 169 ensure that rotation of spindle 161 varies the location of the temperature sensitive element 140 and regulator 130 by varying the location of the spring housing 145. The threads 122, 162 are provided with an 0-ring seal 157, preventing the escape of water from the cartridge 100. The cap 160 is further provided with a spindle 161 by means of which the temperature adjustment can be connected to an external source of rotation.

The mixing chamber body is provided with a thread 129 corresponding to thread 119. This ensures that rotation of the mixing chamber body 120 relative to the outer body 110 results in axial movement of the mixing chamber body 120 relative to the outer body 110. At either end of threads 119, 129 are provided 0-ring seals 153, 154 ensuring that water does not bypass the mixing chamber 121 and helping to prevent the lubricant on the threads being washed away.

The mixing chamber 121 has an exit aperture 127 leading into the exit chamber 117. The mixing chamber body also comprises a valve member 128 provided with a sealing means 125 and connected to the rest of mixing chamber body * **.

by struts 126. Accordingly, rotary motion of the mixing chamber body 120 S. relative to the outer body 110 moves valve member 128 relative to valve seat 118 and * * 20 thus opens (figure 2) or closes (figure 1) a passage for water between exit chamber : 117 and outlet 101.

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The mixing chamber body 120 is provided with an engagable collar 123 enabling the mixing chamber body 120 to be connected to and rotated by an external source. An 0-ring seal 156 is provided to ensure water does not escape above apertures 116, 126 along the side of collar 123. A location disc 170 is provided over the top of outer body 110 to secure the mixing chamber body within the outer body 110.

In operation, a user may rotate spindle 161 to vary the water temperature of the cartridge 100 whilst rotating collar 123 to independently vary the through flow rate of the cartridge 100. The arrangement of the present invention having the flow rate controlled by valve member 128 and valve seat 118 downstream of the temperature regulator 130 combined with larger waterway passages enables an improved flow rate to be achieved with a relatively low pressure hot water supply.

The cartridge 100 might typically be provided in a mixer tap or shower fitting provided with suitable means enabling user rotation of spindle 161 and collar 123.

Turning now to figure 5, as an example a cartridge 100 according to the present invention is provided within a mixer tap 10. The mixer tap is provided with hot and cold water supplies 1, 2 and a mixed water outlet 3. The tap 10 is also provided with a first rotatable element 11 connected to spindle 161 such that rotation of the element 11 causes co-rotation of spindle 161 and a second rotatable element 12 connected to S...

:: 20 collar 123 such that rotation of the element 12 causes co-rotation of collar 123. In this mariner using first and second rotatable elements 11, 12 a user can independently control both the temperature and flow rate of water from outlet 3 whilst achieving a -12 -higher flow rate than is possible using known valves if the water pressure is relatively * low.

It is of course to be understood that the invention is not intended to be limited to the details of the above embodiments which are described by way of example only. **.* * S * *S * *S.. * S S... * . *.

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Claims

-13 -Claims 1. A thermostatic mixer valve comprising: an outer body comprising: a hot water inlet; a cold water inlet; and an outlet valve seat; a mixing chamber body movable axially within the outer body comprising: a mixing chamber for receiving and mixing water from said hot water and cold water inlets; a regulator movable with respect to the mixing chamber in response to variation of water temperature in the mixing chamber to vary the proportions of hot and cold water received by the mixing chamber; and an outlet valve member wherein axial movement of the mixing chamber body within the outer body varies the position of the outlet valve member relative to the outlet valve seat.
2. A thermostatic mixer valve as claimed in claim 1 wherein the valve is in the overall form of a cylindrical cartridge.
3. A thermostatic mixer valve as claimed in claim 1 or claim 2 wherein the valve is provided with a locater pin adapted to fit within a hole provided in the tap body.
4. A thermostatic mixer valve as claimed in any preceding claim wherein the outer body comprises separate internal passageways for the passage of the hot and cold water supplies, the passageways running from the inlets at one end of the :::. outer body to apertures provided on the inner surface of the outer body. ***.
5. A thermostatic mixer valve as claimed in claim 4 wherein the apertures are S.. * S *aligned with the mixing chamber and thus facilitate passage of water from the **...*S S: * inlets to the mixing chamber. *�s S * .5S

-14 -
6. A thermostatic mixer valve as claimed in claim 4 or claim 5 wherein the apertures for the hot and cold supplies are axially displaced relative to one another.
7. A thermostatic mixer valve as claimed in claim 6 wherein the cold water aperture is displaced further towards the distal end of the valve relative to the hot and cold inlets.
8. A thermostatic mixer valve as claimed in any one of claims 4 to 7 wherein the apertures take the form of a circumferential slot.
9. A thermostatic mixer valve as claimed in claim 8 wherein the apertures comprise a series of circumferential slots separated by struts.
10. A thermostatic mixer valve as claimed in any one of claims 4 to 9 wherein the mixing chamber body is provided with corresponding apertures to those in the outer body.
11. A thermostatic mixer valve as claimed in any one of claims 4 to 10 wherein the apertures in the mixing chamber body extend around a substantial proportion of the circumference of the mixing chamber body.
12. A thermostatic mixer valve as claimed in any one of claims 4 to 11 wherein said * : : : apertures comprise a series of circumferential slots separated by struts. 0***
13. A thermostatic mixer valve as claimed in any preceding claim wherein corresponding threads are provided on the inner surface of the outer body and the outer surface of the mixing chamber body.
14. A thermostatic mixer valve as claimed in any preceding claim wherein the * mixing chamber body is provided with an engagable end portion. -15-
15. A thermostatic mixer valve as claimed in any preceding claim wherein the regulator position within the mixing chamber is controlled by a temperature sensitive element operable to expand in response to an increase in temperature in the mixing chamber and contract in response to a decrease in temperature in the mixing chamber.
16. A thermostatic mixer valve as claimed in claim 15 wherein the temperature sensitive element is mounted along the central axis of the mixing chamber.
17. A thermostatic mixer valve as claimed in claim 15 or claim 16 wherein the temperature sensitive element is spring biased.
18. A thermostatic mixer valve as claimed in any one of claims 15 to 17 wherein the temperature sensitive element is provided with a compensation mechanism.
19. A thermostatic mixer valve as claimed in any one of claims 15 to 18 wherein the axial position of the temperature sensitive element within the mixing chamber body is determined by a retaining cap moveable axially relative to the mixing chamber body.
20. A thermostatic mixer valve as claimed in claim 19 wherein the cap provides a mount for the compensation mechanism.

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21. A thermostatic mixer valve as claimed in claim 19 or claim 20 wherein the cap *.S.s is connected with the mixing chamber body by a screw thread thus causing axial 20 motion of the cap relative to the mixing chamber body when rotated.
22. A thermostatic mixer valve as claimed in any one of claims 19 to 21 wherein the cap is provided with an engagable end portion. S..S -16-
23. A thermostatic mixer valve as claimed in any one of claims 15 to 22 wherein the * regulator is mounted directly on the temperature sensitive element.
24. A thermostatic mixer valve as claimed in any one of claims 15 to 23 wherein the regulator comprises an outer cylinder and a central mounting means, the central mounting means being connected to the outer cylinder by one or more spokes or vanes.
25. A thermostatic mixer valve as claimed in any one of claims 15 to 24 wherein the regulator is formed from a suitable plastic or metal.
26. A thermostatic mixer valve as claimed in any preceding claim wherein water exits the mixing chamber into an exit chamber defined by the inner walls of the outer body.
27. A thermostatic mixer valve as claimed in claim 26 wherein the exit chamber additionally comprises the outlet valve seat.
28. A mixer tap incorporating a thermostatic mixer valve according to any preceding claim.
29. A shower incorporating a thermostatic mixer valve according to any one of claims ito 25. * * S S. S *.S. * * *S.* * . S...S *5*55S S * S. S* * S.. *S S..