GB2270964A

GB2270964A - Mixing valve mechanism

Info

Publication number: GB2270964A
Application number: GB9319610A
Authority: GB
Inventors: Stephen Christopher Gannon
Original assignee: NewTeam Ltd
Current assignee: NewTeam Ltd
Priority date: 1992-09-25
Filing date: 1993-09-22
Publication date: 1994-03-30
Anticipated expiration: 2013-09-22
Also published as: GB2270964B; GB9220336D0; GB9319610D0

Abstract

A valve mechanism for mixing hot and cold water comprises first and second fluid inlets 409, 410, and first and second valves respectively arranged to regulate flow of fluid from the first and second inlets. A common control member (not shown) is operably connected to the first and second valves such that continuous or stepwise operation of the control member causes opening and closing of the first and second valves according to a pre-determined sequence. The control member is preferably a manually operable rotatable knob connected to the valves by gearing 103, 104. Each valve comprises a pair of relatively rotatable discs 411, 412. The valve mechanism is of particular utility in shower systems, eg domestic shower systems, when the hot and cold heater are preferably conveyed separately to the shower head. <IMAGE>

Description

Valve Mechanism This invention relates to a valve mechanism, in particular to a valve mechanism for the simultaneous control of the flow of two fluids such as domestic hot and cold water. The valve mechanism is of particular utility in shower systems.

According to the invention there is provided a valve mechanism comprising first and second fluid inlets, first and second valves respectively arranged to regulate flow of fluid from the first and second inlets, and control means operably connected to the first and second valves such that continuous or stepwise operation of the control means causes opening and closing of the first and second valves according to a pre-determined sequence.

The valve mechanism according to the invention is advantageous primarily in that it provides easy and accurate simultaneous control of the flow of both first and second fluids.

The valve mechanism is particularly useful for applications in which the first and second fluids are mixed downstream of the valve mechanism. As mentioned above, the valve mechanism is of particular utility in shower systems, eg domestic shower systems.

According to a further aspect of the invention, therefore, there is provided a shower system comprising a valve mechanism with hot and cold water inlets, hot and cold water control valves arranged to regulate flow of hot and cold water respectively from the hot and cold water inlets to a shower head, and control means operably connected to the hot and cold water control valves such that continuous or stepwise operation of the control means causes opening and closing of the hot and cold water control valves according to a pre-determined sequence.

The valve mechanism of the invention is particularly useful when used in a shower system of the type described in British Patent Application No 2238968A. In this case, the hot and cold water is conducted separately to the shower head. In other applications, the hot and cold water (or other fluids) may pass directly to a mixing chamber immediately downstream of the valve mechanism.

The pre-determined sequence of operation of the first and second valves may involve one valve opening before the other, continued operation of the control means then causing the second valve to open, then the first to close, etc.

When used in a shower system, it is particularly preferred that the control means be a manually operable rotatable knob. The knob is preferably operably connected to the valves by suitable means, eg gearing.

The invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which Figure 1 is a sectional side view of a first embodiment of a valve mechanism according to the invention, Figure 2 is a sectional view along the line II-II in Figure 1, Figure 3 is a schematic view illustrating the mode of operation of the valve mechanism of Figure 1, Figure 4 is a front elevational view of part of a second embodiment of a valve mechanism according to the invention, Figure 5 is a sectional side view of the valve mechanism of Figure 4, Figure 6 shows plan views of ceramic discs forming part of the valve mechanism of Figure 4, and Figure 7 is a view along the arrow VII in Figure 4.

Referring first to Figures 1 and 2, a valve mechanism for use with a domestic shower of the type described in British Patent Application No 2238968A is enclosed within a wall-mounted plastics housing 1. The housing 1 has a generally cylindrical body portion 2 and a rear portion 3 which is also cylindrical and of somewhat greater diameter. Appropriate fixtures (not shown) are provided for fixing of the assembly to a wall. A plastics control knob 10 is located on the front of the unit.

Hot and cold water supply pipes (not shown) are connected to a hot water inlet 4 and a cold water inlet 5 respectively. The hot and cold water inlets 4,5 are in the form of swivel fittings.

The valve mechanism has a screw-threaded outlet 6 which, as can be seen from Figure 2, contains parallel passageways 7,8 for the hot and cold water respectively. Hot and cold water is conducted by a shower hose (not shown) comprising concentric hot and cold water tubes to a shower head (not shown) where mixing occurs.

Cold water enters the valve mechanism via the cold water inlet 5 and passes to the cold water outlet passageway 8 via a cold water ceramic valve 12. The structure of the cold water valve 12 is described in more detail below. Similarly, hot water enters the valve mechanism via the hot water inlet 4 and passes to the hot water outlet passageway 7 via a hot water ceramic valve 13, which too is described in more detail below.

Flow of hot water from the hot water inlet 4 to the hot water outlet 7 is also regulated by a stop valve comprising a sealing disc 15 connected by a control rod 16 to a diaphragm 17. The stop valve is biassed to a closed position by a spring 18. The diaphragm 17 is acted upon by cold water in a pressure chamber 19 upstream of the cold water control valve 12 such that the stop valve is only open so long as there is sufficient cold water pressure in the system. In the event of a catastrophic fall in cold water pressure, the stop valve closes, cutting off the supply of hot water and preventing scalding of the shower user.

The cold water valve 12 comprises a ceramic disc 20 having a pair of sectored apertures 21. The disc 20 contacts and is rotatably mounted upon a valve floor also having a pair of sectored apertures 25. The valve floor apertures 25 are larger in size (ie they subtend a larger degree of arc) than the ceramic disc apertures 21). The disc 20 is rotated by means of a control rod 22 upon which is mounted a valve gear 23. The valve gear 23 in turn meshes with a drive gear 30 mounted on the shaft of the control knob 10.

The hot water valve 13 is similar in construction, comprising a ceramic disc 41 with apertures 42. The disc 41 is mounted on a valve floor with apertures 43 (larger than the disc apertures 42) and is connected via a control rod 44 with a valve gear 45 to the drive gear 30.

The apertures 42 in the hot water valve ceramic disc 41 have an area equivalent to a 13mm internal diameter tube, and the apertures 21 in the cold water valve ceramic disc 20 an area equivalent to an 8mm internal diameter tube.

The mode of operation of the valve mechanism is shown in Figure 3. With the control knob 10 in the OFF position (Figure 3a), the disc apertures 21,42 in both the cold and hot water valve ceramic discs 20,41 are out of registration with the corresponding valve floor apertures 25,43. Both valves 12,13 are therefore closed and flow of both hot and cold water is stopped.

By turning the control knob 10 in the direction of the arrow in Figure 3, both ceramic discs 20,41 are rotated. Because of the relative positioning of the disc apertures 21,43 with respect to the corresponding valve floor apertures 25,43, the cold water valve 12 opens, as a result of the disc apertures 21 coming into registration with the cold water valve floor apertures 25, before the hot water valve 13 opens (see Figure 3b).

Continued rotation of the control knob 10 opens the hot water valve 13, the cold water valve 12 remaining open (Figure 3c) and then closing (Figure 3d).

In the position shown in Figure 3b, the shower is cold and of low flow rate. As the control knob 10 is rotated to the position shown in Figure 3c the temperature and flow rate increase to a maximum at the Figure 3c position. Between the positions shown in Figures 3c and 3d, the temperature of the shower increases but the flow rate decreases markedly.

Referring now to Figure 4, a second embodiment of a valve mechanism according to the invention is likewise intended for the simultaneous control of hot and cold water in a domestic shower system. The mechanism comprises a valve unit 101 which is housed in a plastics housing (not shown). Similarly to the embodiment of Figures 1 and 2, a control knob (not shown) is mounted on the front of the housing.

The control knob (not shown) has a control shaft 102 (shown by broken lines in Figure 4) which meshes with hot and cold water valve gears 103,104 such that rotation of the control shaft 102 causes rotation of the valve gears 103,104 and hence actuation of the hot and cold water valves. Hot and cold water enters the valve unit 101 via swivel fittings 409,410, and passes out of the valve unit 101 through an outlet 430.

The hot and cold water valves are similar and their construction and operation will be described in relation to the cold water valve. Cold water enters the valve mechanism via the swivel fitting 410. The cold water valve itself comprises a pair of abutting, apertured ceramic discs 411,412. The disc 412 on the downstream side of the valve is connected to the cold water valve gear 104 by a cold water valve shaft 415. The shaft 415 is provided at its terminal end with projections 416 which locate in recesses 417 in the downstream ceramic disc 412 (see Figure 6(a)). The downstream ceramic disc 412 is urged into close abutment with the upstream disc 411 by a compression spring 418.

The upstream ceramic disc 411 has a shape with sectored apertures similar to those shown in Figure 3; the downstream ceramic disc 412 has the shape shown in Figure 6(a). The downstream ceramic disc in the hot water valve has the shape shown in Figure 6(b). The shapes of the downstream ceramic discs are chosen to provide the desired operating characteristics, ie the desired proportions of hot and cold water as the hot and cold water valves are opened by rotation of the control knob.

When the hot water and/or cold water valves are open, ie when the cut out portion of one or both downstream ceramic discs is in registration with a sectored aperture in the corresponding upstream disc, water flows through the valve. As can be seen from Figure 7, the hot and cold water flow through separate channels in the outlet 430 of the valve unit 101. Cold water flows through a circular opening 420, and the hot water through a crescent-shaped opening 421. The valve mechanism illustrated, like that of Figures 1 and 2, is intended for use with a shower system of the type described in British Patent Application No 2238968A, in which hot and cold water are conveyed separately to, and mixed in, the showerhead. The outlet 430 is therefore threaded to receive the end of a hose containing parallel passages for hot and cold water.

Claims

1. A valve mechanism comprising first and second fluid inlets, first and second valves respectively arranged to regulate flow of fluid from the first and second inlets, and control means operably connected to the first and second valves such that continuous or stepwise operation of the control means causes opening and closing of the first and second valves according to a pre-determined sequence.

2. A valve mechanism as claimed in Claim 1, wherein the control means is a manually operable rotatable knob.

3. A valve mechanism as claimed in Claim 2, wherein the knob is operably connected to the valves by gearing.

4. A valve mechanism as claimed in one of the preceding claims, wherein the first and/or second valves comprise apertured ceramic discs.

5. A shower system comprising a valve mechanism with hot and cold water inlets, hot and cold water control valves arranged to regulate flow of hot and cold water respectively from the hot and cold water inlets to a shower head, and control means operably connected to the hot and cold water control valves such that continuous or stepwise operation of the control means causes opening and closing of the hot and cold water control valves according to a pre-determined sequence.

6. A shower system as claimed in Claim 5, wherein hot and cold water are conveyed separately to the shower head.

7. A shower system as claimed in Claim 5 or Claim 6, wherein the control means is a manually operable rotatable knob.

8. A shower system as claimed in Claim 7, wherein the knob is operably connected to the valves by gearing.

9. A shower system as claimed in one of Claims 5 to 8, wherein the first and/or second valves comprise apertured ceramic discs.

10. A valve mechanism substantially as hereinbefore described.

11. A valve mechanism substantially as hereinbefore described with reference to Figures 1 to 3.

12. A valve mechanism substantially as hereinbefore described with reference to Figures 4 to 7.