GB2075831A - Shower mixers - Google Patents

Abstract

The invention provides a shower mixer including a mounting box 4, a blending valve 20, Figure 2, supported in the mounting box 4 and having means for controlling water flow and temperature and a pump 22 supported in the mounting box for receiving water from the blending valve and conveying it to a shower head. In a convenient construction the blending valve 20 includes a first valve member 40, Figure 3, rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of hot water, a second valve member 40 rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of cold water and a mixing chamber 42 for receiving flows from the respective passages, the arrangement being such as to cause only a small pressure drop across the blending valve. The pump 22 is a low head type pump for increasing the pressure of water flowing to the shower head. <IMAGE>

Description

SPECIFICATION Shower mixers Field ofinvention The invention relates to shower mixers for use especially in shower installations.

Background ofinvention A variety of mixing valves for shower mixers are known. These generally have a value means for regulating temperature and separate control valve for regulating flow. These valves generally incorporate an integral mixing chamber. These mixers require a considerable head of water for satisfactory performance. Such a head is not always available and cannot be provided economically in some cases.

Summary ofinvention According to this invention there is provided a shower mixer including a mounting, a blending valve means supported in the mounting which has means for controlling water flow and temperature and a pump supported in the mounting for receiving water from the blending valve means and conveying it to a shower head.

This provides a convenient package for installation in flats or under other circumstances in which insufficient head is available to work a shower The output of shower heads can be boosted in a relatively simple manner.

Preferably the blending valve means includes a first valve member rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of hot water, a second valve having a valve member rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of cold water and a mixing chamberfor receiving flows from the respective passages, the arrangement being such as to cause only a small pressure drop across the blending valve and the pump is a low head type pump for increasing the pressure of water flowing to the shower head. This combination permits a considerable shower head flow to be achieved with an economic pumping arrangement. Suitably the mounting is a box-like construction containing the blending valve means and the pump.Advantageously each of the valve members have a spindle and gears or gear segments are mounted on the spindles and a regulating means is provided including a gear for operating the respective gear or gear segments simultaneously.

Preferably the regulating means is arranged so that closing of the water flow returns the blending valve means to a cold water setting and the regulating means is arranged so that when water flow is opened the pump is operated.

Preferably the mixing chamber is a separate plastics body interposed between the valve member and the pump inlet. Preferably then the valves are butterfly valves having resilient sealing members on the valve members The valves may also be spool valves with a diametrically extending bore for conveying water and having annular rings above and below the bore for sealing.

Advantageously the spindles are controlled by gears so as to first open the valve for cold water and then open the valve the hot water whilst the cold water valve is closed simultaneously.

This can be achieved by rotating the spindle for the cold water valve conjointly with a knob of the regulating means and operating the spindle for the hot water valve through a lost motion device only after the cold water spindle has been turned to the open position.

No separate flow control valve need thus to be used reducing pressure losses in the installation arising from the mixing valve. The butterfly valves only bring about a small pressure loss and enable accurate adjustment of the temperature to be made.

The design is simple and economic.

The "low head" type pump may be of the kind mass produced for washing machines. Such pumps can be connected to the mixing chamber outflow port and raise the water outflow so as to overcome a low head in the hot and/or cold water supply and give an effective output of showers in the region of 1-2 gallons per minute. These pumps can run dry but are inherently inefficient thus giving low output pressures and functioning optimally only with low flow resistances on the inflow side as provided by the blending valve means of the general type described.

Drawings Figure 1 shows a front elevation of a mixing valve/pump assembly according to the invention; Figure 2 shows a front view with cover removed of the assembly of Figure 1; and Figure 3 shows a part section through the mixing valve of Figure 1.

Description ofpreferred embodiment An assembly 2 (see Figure 1) includes a box 4 for mounting on a wall and a lid 6 with ventilation louvres 8 and a protruding control knob 10. The box 4 has an inlet 12 for cold water and inlet 14 for hot water and an outlet 16 for mixed hot and/or cold water.

Inside the box 4 (see Figure 2) there are mounted a mixing valve 20 and a pump 22.

The pump 22 is a conventional centrifugal washing machine type pump with an inlet 24, an outlet 26 connected to the outlet 16, a centrifugal vane housing 28, and electric motor 30, a cooling fan 32 and an electric ON/OFF switch 34.

The mixing valve 20 (see Figure 3) has a pair of butterfly valves 40 connected to a mixing chamber 42. Each valve 40 has a brass housing 44 and a butterfly valve member 46 including a spindle 48, plates 50 and a sealing ring 52. The valves 40 may be as described in the British Patent Specification 1,421,700. The housings 44 are screwed into the plastics chamber 42.

The valves 40 and chamber 42 are secured to a mounting plate 60 (see Figure 2) through which the spindles 48 protrude. Each spindle 48 is fast to a gear 62,63 which in turn meshes with gears 64,65 one above the other on a control knob spindle 66; The detailed gear arrangement is as follows. The gear 62 for the cold water spindle 48 and gear 64 are meshed continuously with one another and are both fastto their respective spindles so that, on a 180" turn of the control knob 10, the coid water valve 40 can move from a closed to a fully open position and from thereto a closed position (see Figure 1). The gear 65 for the hot water spindle 48 is rotatably journalled on the spindle 66. The gear 65 is driven by a gear portion 68 of the gear 62 which has no gear teeth over an arc of 90" and forms a recess 69.The gear 65 in turn meshes constantly with the gear 63 on the spindle 48 of the hot water valve 40. The recess 69 is arranged so that the turning of the control knob from the closed position causes no effect on the setting of the hot water valve 40 for the first 90 of control knob turn as the recess 69 is alongside the gear 65. At this stage only the cold watervalve 40 is opened. The hot water valve 40 remains closed. Then the hot water valve 40 starts opening as the recess 65 has passed and the gear portion 68 commences to actwhilstthe cold water valve 40, having been opened previously, starts to close. The hot water spindle 48 is thus operated during the finai 90" of control knob turn through a gear fixed with the control knob 10, the cold water valve gear 62, the gear rotatable on the control knob spindle 66 and the hot water valve gear 63. The control knob 10 can be connected to operate the pump switch 34 as soon as the cold water valve 40 is opened.

The overall assembly is simple and economic to manufacture as it uses mass produced parts. The control knob arrangement prevents scalding on turning on the shower. The pump has to be below the head of the water supply to ensure it is primed, but other than that the assembly will give a satisfactory flow for showers under very low head conditions using existing warm water tanks. The box4 and its contents can be installed in a convenient manner.

Claims (10)

1. A shower mixer including a mounting, a blending valve means supported in the mounting which has means for controlling water flow and temperature and a pump supported in the mounting for receiving water from the blending valve means and conveying itto a shower head.

2. A shower mixer according to claim 1 in which the blending valve means includes a first valve member rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of hot water, a second valve having a valve member rotatable about an axis extending substantially at right angles to an associated passage for regulating flow of cold water and a mixing chamber for receiving flows from the respective passages, the arrangement being such as to cause only a small pressure drop across the blending valve, and in which the pump is a low head type pump for increasing the pressure of water flowing to the shower head.

3. A shower mixer according to claim 1 or claim 2 in which the mounting is a box-like construction containing the blending valve means and the pump.

4. A shower mixer according to claim 2 or claim 3 in which each of the valve members have a spindle and gears or gear segments are mounted on the spindles and a regulating means is provided including a gearforoperating the respective gear or gear segments simultaneously.

5. A shower mixer according to claim 4 in which the regulating means is arranged so that closing of the water flow returns the blending valve means to a cold water setting.

6. A shower mixer according to claim 5 in which the regulating means is arranged so that when water flow is opened the pump is operated.

7. Ashower mixer according to any of claims 2 to 6 in which the mixing chamber is a separate plastics body interposed between the valve member and a pump inlet.

8. A shower mixer according to any of claims 2 to 7 in which the valves are butterflyvalves having resilient sealing members on the valve members.

9. A shower mixer according to any of claims 5 to 8 in which the regulating means is arranged so as to first open the valve for cold water and then open the valve for hot water whilst the cold water valve is closed simultaneously.

10. Ashower mixer substantially as shown in and as described with reference to the drawings.