GB2108634A

GB2108634A - Hot and cold water mixer tap with a single control

Info

Publication number: GB2108634A
Application number: GB08225107A
Authority: GB
Inventors: Daniel Meylan
Original assignee: Kugler Fonderie et Robinetterie SA
Current assignee: Kugler Fonderie et Robinetterie SA
Priority date: 1981-11-02
Filing date: 1982-09-03
Publication date: 1983-05-18
Also published as: CH643641A5; AU8798282A; GB2108634B; AU549152B2

Abstract

A mixer tap has a stationary ceramic disc (17) and a ceramic disc (24) which is movable in rotation and in translation by the action of a mechanism (27, 32, 33, 34, 35). The movable disc (24) contains two apertures (25, 26) which interact respectively with pairs of apertures (19, 20) and (21, 22) in the stationary disc (17), whereby the paths of hot and cold water are entirely separate in the mixer. Relative translation of the discs (17, 24) causes a change in the ratio of the outputs of hot and cold water, while relative rotation of the disc (17, 24) causes a simultaneous, identical change in the outputs of both hot and cold water. <IMAGE>

Description

SPECIFICATION Mechanical mixer with ceramic discs under a single control The invention relates to a mechanical mixer with ceramic discs under a single control.

Mechanical mixer taps with ceramic discs under a single control have been previously proposed, for example in French Patent 77 27802, published German Patent Application OS 29 07 978 or published European Patent Application 00 22 590.

All these known mechanical mixer taps have at least two ceramic discs containing apertures, at least one of which is movable in translation and in rotation relative to the other discs. Such mixers can be adjusted by means of a single control member, which can cause translation of the movable ceramic disc to adjust the flow rate, and rotation of the movable ceramic disc to adjust the temperature.

These known arrangements are satisfactory when the hot and cold water can be mixed inside the actual mixer, and when the outlet spout of the mixer discharges a mixture of hot and cold water.

In some special applications, and also to satisfy standards fixed by legislation, it is necessary for the hot and cold water to be completely separate until they leave the spout of the mixer tap, that is to say, the hot and cold water are not mixed until they leave the spout of the mixer tap, and the mixer tap must then have two separate outlet passages.

Known mechanical mixer taps are not adapted to these special applications, and it is among the objects of the invention to provide such a mixer tap, with ceramic discs and a single control, in which the hot water and the cold water are separate until they leave the spout of the mixer tap.

According to the invention, there is provided a mechanical mixer with ceramic discs with a single control, comprising a housing containing a stationary ceramic disc, a ceramic disc which is movable in translation and in rotation relative to the stationary disc and a mechanism for dispiacing the movable disc and controlled by a control member rising out of the housing, the housing having two inlet orifices to admit water, one for hot water and the other for cold, and also having two outlet orifices, one for hot water and the other for cold; and wherein the stationary disc has a pair of first apertures therein, communicating with the inlet and outlet orifices for cold water, and a pair of second apertures therein, communicating with the inlet and outlet orifices for hot water; the movable disc has a first aperture therein which, according to the relative position the movable disc relative to the stationary disc, can establish communication between the pair of first apertures in the stationary disc and a second aperture which can establish communication between the pair of second apertures in the stationary disc; the mechanism for driving the movable disc limits its displacements, so that the pair of first apertures in the stationary disc are never put into communication with the pair of second apertures in the stationary disc; and translation of the movable disc causes a relative change in the outputs of hot and cold water in order to change the temperature, while rotation of the movable disc brings about a virtually identical change in the outputs of hot and cold water.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Figure 1 is an axial cross-section through a mechanical mixer tap according to the invention; and Figures 2 to 6 are plan views showing the position of stationary and movable ceramic discs of the mechanical mixer tap of Figure 1 for different operating conditions.

Referring to the drawings, a mechanical mixer tap comprises a housing 1 preferably made of brass, of generally cylindrical shape and having an end wall 2 in which four orifices are provided. Two outer ones 3, 6 of the orifices are designed to be connected to pipes respectively supplying hot and cold water, while two inner ones 4, 5 of the orifices are designed to be connected to passages respectively discharging hot and cold water. Part of the internal cylindrical wall of the housing 1 has a screw thread 7 interacting with a fixing nut 8.

Inside the housing 1 is a socket 9 containing a mixer mechanism. The socket 9 is gripped between the fixing nut 8 and a bottom disc 10, which bottom disc 10 is made of plastics and lies against the end wall 2 of the housing 1. The bottom disc 10 is provided with four apertures 11, 12, 13, 14 communicating respectively with the orifices 3, 4, 5 and 6 in the end wall 2 of the housing 1 of the mixer. The angular position of the bottom disc 10 is determined by a positioning finger 1 5 on the socket 9, interacting with a corresponding recess in the periphery of the disc 10.Seals 1 6 ensure that there is no leakage between the bottom disc 10 and the end wall 2 of the housing 1 , to avoid any undesired communication between the orifices 3, 4, 5, 6 and the apertures 11,12,13,14.

The mixer tap further comprises a stationary ceramic disc 17 placed on the bottom disc 10. Its angular position is similarly fixed by the positioning finger 1 5 on the socket 9, interacting with a notch 1 8 in the stationary disc 17.

The stationary ceramic disc 17 contains two pairs of apertures 19, 20 and 21, 22, communicating respectively with the apertures 11,12,13, in the bottom disc 10 and the orifices 3, 4, 5 and 6 in the housing 1.

Seals 23 ensure that there is no leakage between the bottom disc 10 and the stationary ceramic disc 17, to avoid any undesired communication between the respective apertures 11,12,13,14andorifices 19,20,21 and22.

A movable ceramic disc 24 is placed on the exposed surface of the stationary ceramic disc 17.

The flat surfaces of the two ceramic discs 1 7 and 24 have a sealing effect in the places where they are in contact. The movable disc 24 contains two apertures 25 and 26. As will be seen later, these interact with the respective pairs of apertures 19, 20 and 21,22 in the stationary ceramic disc 17.

A mechanism for driving the movable ceramic disc 24 in its movements of translation and/or rotation relative to the stationary ceramic disc 1 7 comprises an intermediate member 27, bearing against the exposed upper surface of the movable disc 24. The intermediate member 27 contains two cavities 28, 29, communicating respectively with the apertures 25, 26 in the disc 24 and forming independent chamber. A seal 30 ensures that there is no leakage between the intermediate member 27 and the movable disc 24 around the apertures 25, 26 therein. The intermediate member has a driving finger 31 engaged in a corresponding notch in the movable disc 24.The intermediate member 27 has a recess in its upper surface, housing a spherical end 32 of a steel control lever 33, which is pivoted about a shaft 34, extending parallel with the plane of the ceramic discs 17, 24, and rigidly mounted in an operating head 35, which extends across the opening at the top of the socket 9. A lower abutment 36, formed by an edge of the operating head 35, and a fixing ring 37 secure the axial position of the operating head 35 relative to the socket 9, while allowing relative rotational movement between the two components.

Abutments (not shown) may be provided to limit the relative angular displacement between the socket 9 and the operating head 35. The nut 8, fixing the socket 9 onto the housing 1, thus keeps the whole mixer mechanism in position in the housing 1 at a specific pressure, to ensure that the unit is impervious to leaks while also allowing it to operate.

It will be seen that the hot and cold water are completely separated, from the inlet to the outlet of the mixer. The hot water is introduced through the orifice 3, passes through the apertures 11, 1 9 and 25 into the chamber 28, and leaves the chamber 28 through the apertures 25, 20 and 12 and the discharge orifice 4. Similarly the cold water enters the mixer through the orifice 6, passes through the apertures 14, 22 and 26 to enter the chamber 29, and leaves the chamber 29 through the apertures 26, 21 and 13 and the discharge orifice 5. The hot and cold water paths are thus entirely separate.

The mechanical mixer described operates as follows: a. Rotation of the control lever and thus rotation of the discs 1 7 and 24 relative to one another causes virtually identical changes in the flow rate of the hot water and the cold water, by changing the cross-section of passage between the apertures 1 9 and 20 and between the apertures 21 and 22 by a substantially equal amount.

Rotation of the control lever thus leads to a virtually identical change in the flow rate of both waters, and hence the mixture of the waters, made after leaving the mixer, remains at a constant temperature.

b. Translation of the movable disc 24 relative to the stationary disc 17, caused by pivoting the control lever about the shaft 34, produces a change in the proportions of hot and cold water passing through the mixer, without thereby changing the existing flow rate of hot and cold water. Thus, the translation brings about change in the temperature of the water which is mixed after leaving the mixer, without changing the flow rate of the mixed water.

c. It is clear that simultaneous pivoting and rotating movements of the control lever can change both the total output of the mixer and the temperature of the mixture of hot and cold water made after leaving the mixer.

Figure 2 illustrates the position of the ceramic discs 1 7 and 24 when the mixer is closed, when the outputs of hot and cold water are both zero, and for a mean temperature. It will in fact be seen that the apertures 1 9, 20 are not linked by the aperture 25, and that the apertures 21, 22 are not linked by the aperture 26 either. The mixer is thus closed. On the other hand, since the movable disc 24 is centred on the disc 17, the sections of passage between the apertures 20 and 25 and between the apertures 21 and 26 are equal.

Figure 3 illustrates the mixer still in the closed position with the relative angular position of the discs 17 and 24 the same as in Figure 2. However, since the disc 24 is shifted a distance S in the direction of the arrow F relative to the disc 17, the sections of passage between the apertures 20 and 25 and between the apertures 21 and 26 are different, corresponding to different outputs of hot water and cold water.

In Figure 4, the discs 1 7 and 24 are shown shifted to the maximum in translation, as in Figure 3, giving different sections of passage for cold water and hot water. However, the disc 24 has also been displaced angularly relative to the stationary disc 17, through an angle a. While still closed the mixer is only just closed, that is to say the apertures 1 9 and 25 are almost in communication, as are the apertures 22 and 26.

In Figure 6, the discs 24 and 17 are still staggered by the maximum value S but their angular position is staggered by an angle a of 900. In this position, the section of passage between the apertures 19, 26, 20 is at its maximum, giving a maximum output of hot water.

On the other hand, the section of passage between the apertures 22 and 25 is zero, so the output of cold water is zero. The mixer thus delivers a maximum output of hot water.

In Figure 5, the discs 24 and 1 7 are shown staggered at an angle a of 900, corresponding to the maximum output, but the linear shift S between the discs is zero, corre sponding to the mean temperature. It will be seen that for this position the apertures 1 9, 20, 26 are in communication, as are the apertures 21.22. 25, so that the mixer delivers hot water and cold water.

In this position, the section of passage between the apertures 1 9, 20 and between the apertures 21,22 are identical, giving identical outputs of hot water and cold water and thus a mean temperature for the mix.

The shape of the apertures 19, 20, 26 and 21, 22, 25 is chosen so that, whatever the linear shift S; relative rotation of the discs 1 7, 24 will cause a virtually identical change in the sections of passage through the apertures 19, 20 and through the apertures 21, 22, so that only the output of the mixer will be changed and not the proportion of hot to cold water.

Similarly, with this shape of the apertures 1 9, 20,26 and 21,22,25, a relative linear displacement S of the discs 17, 24 leads to a respective reduction or increase in the section of passage between the apertures 19, 20 and a virtually identical respective increase or reduction in the section of passage between the apertures 21, 22. The output of the mixer therefore remains constant, but the proportion of hot to cold water is changed.

The mechanical mixer described can have excellent hydraulic properties, that is to say, it has sections of passage for adequate outputs of hot and cold water; this cannot be done with known apparatus if the mixer is required to have the hot and cold water separate.

By reversing the control movements -- so that rotation controls output and translation controls temperature -- relative to known mixers, and by having particularly shaped apertures in the discs, it has been possible to provide a mechanical mixer with ceramic discs under a single control, whereby the hot and cold water can be completely separated. The outputs of hot and cold water can be mixed in a place chosen by the user, downstream of the mixer.

The shape of the apertures in the discs 1 7 and 24 is obviously important in preventing translation of the discs from affecting output, and conversely in preventing rotation of the discs from affecting the ratio of hot to cold water.

In the example illustrated, the inlet apertures 19, 22 in the stationary disc 17 have an elongate, slightly incurved shape, with the external edge substantially parallel with the periphery of the disc. The inner edge of the apertures has a central incurved portion, concentric with the disc, and two straight end portions. The two apertures 1 9, 22 are identical in shape and dimensions and are arranged symmetrically relative to the centre of the disc 17.

The outlet apertures 20, 21 in the disc 1 7 are also arranged symmetrically relative to the centre of the disc 17 and are located between the apertures 19, 22. The apertures 20, 21 have a narrow end, the width of which increases gradually to the centre of the aperture, then from the central point of maximum width, the width of the aperture decreases in the direction of its other end, although this is still wider than the narrow end.

The apertures 25, 26 in the movable ceramic disc are shaped so that, for at least one angular position of the movable disc 24 relative to the stationary disc 17, corresponding to the closed position of the mixer, the two apertures 25, 26 are not in communication with the apertures 19, 22 in the stationary disc.

Similarly the apertures 25, 26 in the movable disc 24 must be shaped so that, when the mixer is in the fully or partially open position, with maximum translation of the discs 1 7 and 24, the aperture 25 does not communicate with the aperture 22 or the aperture 26 with the aperture 1 9.

Claims

1. A mechanical mixer with ceramic discs with a single control, comprising a housing containing a stationary ceramic disc, a ceramic disc which is movable in translation and in rotation relative to the stationary disc and a mechanism for displacing the movable disc and controlled by a control member rising out of the housing, the housing having two inlet orifices to admit water, one for hot water and the other for cold, and also having two outlet orifices, one for hot water and the other for cold; and wherein the stationary disc has a pair of first apertures therein, communicating with the inlet and outlet orifices for cold water, and a pair of second apertures therein, communicating with the inlet and outlet orifices for hot water; the movable disc has a first aperture therein which, according to the relative position of the movable disc relative to the stationary disc, can establish communication between the pair of first apertures in the stationary disc and a second aperture which can establish communication between the pair of second apertures in the stationary disc; the mechanism for driving the movable disc limits its displacements, so that the pair of first apertures in the stationary disc are never put into communication with the pair of second apertures in the stationary disc; and translation of the movable disc causes a relative change in the outputs of hot and cold water in order to change the temperature, while rotation of the movable disc brings about a virtually identical change in the outputs of hot and cold water.

2. A mechanical mixer with ceramic discs under a single control substantially as hereinbefore described and illustrated with reference to the accompanying drawings.