GB2156495A - Valves - Google Patents

Abstract

A valve which is intended for water supply systems with high pressure on the cold and low pressure on the hot water side and preferably has separable passages for the hot and cold water up to the end of the tap outlet spout (8), has two disc-shaped control elements (10, 11) of which disc (10) serves as the static valve seat and contains an inlet aperture (12) for the cold water and an inlet aperture (13) for hot water. The inlet aperture (12) interacts with a deflection chamber (14) formed by a surface channel in the moving disc (11), this latter being movable on the static disc (10) and serving to deflect the cold water to an outlet port (16) which is also preferably located in the valve seat disc (10). The inlet aperture (13) for the hot water interacts with the outer contour of the moving disc (11), the edge of which acts as the control edge (18) movement of which covers or exposes the inlet aperture (13). The hot water inlet aperture (13) preferably has a larger flow cross-section than that of the cold inlet aperture (12) and is located at a larger radius from the centre of the static disc (10) than is the latter, to provide balanced control in spite of supply pressure differences. <IMAGE>

Description

SPECIFICATION Single control hot and cold water supply valve The subject matter of this invention is a sanitary single-control valve for hot and cold water supply systems, for use particularly al though not exclusively where the cold water is at mains pressure (high) and with low pres sure on the hot water side. The valve is of the kind with at least two disc-shaped control elements of which one disc has two inlet through apertures for the cold and hot water supplies, one inlet aperture of which coop erates with a surface channel in the other disc to guide water to an outlet port.

Mixer valve assemblies for water supply systems used in certain applications must in some countries, for example in Great Britain, be equipped with separate passages for the cold and hot water up to the end of the tap outlet in order to prevent so-called cross-flow phenomena occurring between the cold and hot water pipes, something which can be detrimental to both hygiene and functional reliability. Moreover, the differences in pres sure in the hot and cold water supply systems may be quite considerable. It is, for example, not unusual for the hot water pressure to be 0.2 bar gauge with a cold water pressure of 2 bar gauge.

In a known single-lever valve assembly, a static valve seat disc contains a pair of cold and hot water ports for both the inlet and the outlet of the water, whereby the incoming cold and hot water is guided by means of deflection chambers in the moving disc to the outlet ports in the fixed valve seat disc. A mixer valve assembly of this kind is described in UK patent specification 2 108 634 A.

The disadvantage with this design is that the flow rate on the hot water side is unsatis factory owing to its considerably lower pres sure compared with the cold water side be cause the passage cross sections in the discs are identical for both the cold and low water sides. This means that owing to the consider bly lower hot water pressure, a correspon dingly lower flow rate is obtained.

An increase in the passage cross sections of the hot water side would only be feasible in this known construction by means of increas ing the dimensions of the discs, which, in turn, would mean making the mixer valve assembly bigger. Even if this were acceptable, there would remain the disadvantage that with the tap control at mid-position, too much cold water would still flow through the valve as sembly as it would not be possible to increase the passage cross section on the hotwater side without also increasing the passage cross sec tion on the cold water side because only in this case would it be possible to maintain independent control of water flow and water temperature.

In addition, there would be the problem that deflection of the cold and hot water to the outlet ports in the static valve seat disc would bring with it considerable design and technical problems as regards the manufacture of independent water passages. Moreover, the multiple deflection of the flow would noticeably further throttle the flow rate on the hot water side owing to the considerably lower pressure there.

This known design also has the disadvantage that operation of the control lever is such that, in contrast to conventional mixer valve assemblies, the water flow is controlled by turning the lever, and the water temperature by vertical adjustment of the lever. In the case of control of the temperature, there is the problem here that the temperature position of the control lever is hardly distinguishable.

Furthermore, owing to the relatively small angle of lever adjustment for temperature control, there is a correspondingly small comfort zone within the usual mixed water temperature ranges.

Certain embodiments of the present invention overcome these disadvantages and provide a sanitary single-lever mixer valve assembly which, in spite of being of simple design, ensures reliable operation.

According to the present invention, there is provided a water valve for controlling the supply of hot and cold water, having a single control member, and including at least two superimposed relatively-movable disc-shaped control elements of which one disc contains two inlet through apertures for hot and cold water respectively, the other disc having a surface channel which can be brought to overlie one of the inlet apertures for directing water from that inlet to an outlet port for that water, and in which the other inlet aperture interacts with a portion of the outer contour of the other disc which outer contour portion acts as the control edge for exposing or covering that other aperture, upon relative movement of the discs, to allow, or not, water from that other aperture to pass to the or a further outlet port of the valve.

Thus in the valve of the invention, the inlet aperture for the hot water at low pressure, for example, interacts with the moving disc outer contour which serves as the control edge.

Preferably, the one disc having the two inlet apertures also has an outlet aperture which constitutes the outlet port to which water is directed from the one inlet aperture by the surface channel in the other disc.

Conveniently, the one disc having the two inlet apertures is mounted in the valve to be static, the one inlet aperture with which the surface channel cooperates being the cold water inlet aperture and the other inlet aperture being the hot water one, and the other disc is movably mounted.

With a single-control valve in accordance with the invention, there are no design or manufacturing problems involved in increasing the passage cross-section of the hot water inlet aperture in relation to the cold water inlet aperture. It can even be made double the size without the need of increasing the diameter of the discs. A further advantage of the invention is that no deflection is required to the valve seat disc for the hot water side where particularly favourable flow conditions are desirable.

The incoming hot water flows laterally passed the moving valve disc directly to the tap outlet.

According to a preferred feature of the invention, the one (e.g. cold) water inlet aperture lies on a smaller radius that the other (e.g. hot) water inlet aperture from the centre of the static disc, and the radial extent of the two inlet apertures is essentially the same.

This simple design feature ensures that in spite of the differing sizes of the inlets for cold and hot water, control of the flow and temperature can take place practically without these two parameters influencing each other. This is because the percentage change in the cross sections of the two inlet ports is virtually the same.

The invention may be put into practice in many ways but one specific embodiment will now be described, by way of example, with reference to the drawings, in which: Figure 1 shows a longitudinal section through a kitchen tap system in mix position with a swivellable outlet spout; Figure 2 shows a static valve seat disc with a moving disc on top in closed, mid-temperature position, as viewed in section on line A-A of Fig. 1; Figure 3 shows the discs in semi-opened mid-temperature position; Figure 4 shows the discs in fully opened mid-temperature position; Figure 5 shows the discs in fully opened cold-water position; and Figure 6 shows the discs in fully opened hot-water position.

In Fig. 1 of the drawings the valve assembly housing is identified with reference 7, and the swivellable outlet spout with 8. As can be seen, the mixer valve assembly contains a cartridge 9 with two control elements in the form of discs 10 and 11 of which one is the static valve seat disc 1 0. This static disc 10 is provided with inlet through apertures 12, 1 3 respectively for cold and hot water. Of these, the inlet aperture 1 2 for the cold water interacts with a deflection chamber 14 formed by a surface channel in the second disc 11 which is moved on the valve seat disc 10 by means of a single control member formed as a lever 1 5 and guides the cold water to an outlet port 1 6 which is also located in disc 10.From there, the cold water flows via passages 1 7 in the housing 7 to the swivellable outlet spout 8.

As can be further seen from Figs. 2 to 6, the inlet aperture 1 3 for the hot water interacts with a portion of the outer contour of the sealing face 1 9 of the moving disc 11, whereby the edge of the sealing face 1 9 acts as the control edge 1 8 movement of which exposes or covers the inlet aperture 1 3. The inlet aperture 1 2 for the cold water lies on a radius 20a taken from the centre of the static disc 10, which radius is smaller than that on which the inlet aperture 1 3 for the hot water lies,which is located on radius 20b, this latter radius being half the total radius of the disc 10.The radial extent of the two inlet apertures 1 2 and 1 3 are essentially the same, but the hot water inlet aperture 1 3 has a larger cross-sectional area of flow than that of the cold water inlet aperture 1 2.

In contrast to the cold water flow path, the hot water is not deflected to an outlet port in the static valve seat disc 10 but instead flows via a recess 21 in the moving disc 11 laterally passed the static valve seat disc 10 and is guided through passages 22, 23 of the cartridge 9 and the tap housing 7 into a tubular passage 24 which is located in the swivelling outlet spout 8. This tubular passage 24 extends up to the end of the outlet spout and is surrounded by the cold water flow in the mixing mode.

The guide passages for the cold and hot water are separate through the entire mixer valve assembly so that when the tap is operating in the mixing mode, the low-pressure hot water flow is not influenced by the cold water flow which may, for example, be under 10 times the pressure of the hot supply.

In spite of these considerable pressure differences, the guide and control system for the hot water incorporated in the valve of the invention ensures that the hot water flow is always sufficient for obtaining the desired mixed water temperature owing to the fact that no matter what is the mixing position, the hot water passage cross section is always larger by virtually the same percentage.

The mixer valve assembly depicted is operated by the lever 1 5 as is usually the case with conventional single-lever mixers (e.g. in accordance with DT-AS 1 5 50 060), i.e. vertical adjustment of the lever 1 5 controls the water flow while lever rotation controls water temperature. The lever 1 5 incorporates a finger 25 which engages in a recess 26 in the moving disc 11 which is thus moved bodily in a linear direction by the lever for controlling water flow, and rotated around the cartridge centre axis for temperature control. The moving control disc 11 together with a sealing disc 27 forms the external cartridge seal so that no dynamic loading takes place on seals of soft material.

The illustrated embodiment constitutes one example embodiment of the invention and the invention is not limited to this possibility; rather, the basic concept of the invention provides for other design possibilities regarding the arrangement and construction of the individual components and also the type of fitting. For example, a mixer valve assembly in accordance with the invention can also take the form of a wash basin tap assembly or designed as a surface-mounted or flushmounted tap assembly.

Claims (9)

1. A water valve for controlling the supply of hot and cold water, having a single control member, and including at least two superimposed reiatively-movable disc-shaped control elements of which one disc contains two inlet through apertures for hot and cold water respectively, the other disc having a surface channel which can be brought to overlie one of the inlet apertures for directing water from that inlet to an outlet port for that water, and in which the other inlet aperture interacts with a portion of the outer contour of the other disc which outer contour portion acts as the control edge for exposing or covering that other aperture, upon relative movement of the discs, to allow, or not, water from that other aperture to pass to the or a further outlet port of the valve.

2. A water valve as claimed in claim 1, in which the one disc having the two inlet apertures also has an outlet aperture which constitutes the outlet port to which water is directed from the one inlet aperture by the surface channel in the other disc.

3. A water valve as claimed in claim 1 or claim 2, in which the one disc having the two inlet apertures is mounted in the valve to be static, the one inlet aperture with which the surface channel cooperates being the cold water inlet aperture and the other inlet aperture being the hot water one, and in which the other disc is movably mounted.

4. A water valve as claimed in claim 3, in which the inlet aperture for cold water lies on a radius from the centre of the static disc which is smaller than the radius on which the inlet aperture for hot water lies, the radial extent of the inlet apertures being substantially the same as each other.

5. A water valve as claimed in any one of claims 1 to 4, in which the inlet aperture in the one disc, which interacts with the portion of the outer contour of the other disc, has a larger cross-sectional area of flow than that of the other inlet aperture.

6. A water valve as claimed in any one of the preceding claims, in which the control elements are located in a cartridge having an outlet port to which water is directed from the inlet aperture in the one disc, which interacts with the outer contour of the other disc, which outlet port is separate from the outlet port to which water is deflected by the surface channel of the other disc.

7. A water valve as claimed in claim 6, in which the separate outlet ports communicate with discrete passages for feeding the separate water supplies to a tap outlet of the valve.

8. A water valve as claimed in claim 7, in which the discrete passages and the tap outlet are provided in a swivellable spout of the valve.

9. A water valve as claimed in any one of the preceding claims, when installed, the inlet aperture in the one disc with which the surface channel in the other disc cooperates being connected to a water supply at relatively high pressure and the other inlet aperture being connected to a water supply at a relatively low pressure.

1 0. A water valve substantially as specifically described herein with reference to the drawings.