GB2047552A

GB2047552A - Liquid mixer valve and pump assembly

Info

Publication number: GB2047552A
Application number: GB8009713A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-03-23
Filing date: 1980-03-21
Publication date: 1980-12-03
Also published as: GB2047552B

Abstract

A combined liquid mixer valve and pump assembly for use in controlling the flow of a liquid formed by mixing two liquids (such as hot water and cold water) in variable proportions. The mixer valve has a mixing chamber (11) connected to two liquid inlets (12 and 13) and a liquid outlet (14), a slidable valve member (18) and a rotatable control member (15) connected to said valve member (18) for varying in use the relative proportions of the two liquids entering the mixing chamber. The pump assembly comprises a pair of pumps (28 and 29) having outlets connected respectively to said liquid inlets and driven in use by an electric motor 31 to feed the two liquids to the mixer valve at substantially equal pressures. <IMAGE>

Description

SPECIFICATION Liquid mixer valve and pump assembly This invention relates to a combined liquid mixer valve and pump assembly that is especially (but not exclusively) intended in use to provide from its outlet a flow of water at a desired temperature by mixing a supply of cold water and a supply of hot water. Such an arrangement may be used for example to provide water for personal washing purposes in the home (for example in a shower or a bath), in a caravan or in a boat. One object of the invention is to provide a combined liquid mixer valve and pump assembly in an improved form.

In accordance with one aspect of the present invention there is provided a combined liquid mixer valve and pump assembly wherein said valve has a pair of liquid inlets, a mixing chamber connected to said liquid inlets and to a liquid outlet and movable control means which are adapted in use to vary the relative rates of flow of two liquids flowing through said liquid inlets into the mixing chamber and thence through the liquid outlet, and wherein said pump assembly comprises a pair of pumps each having a liquid inlet and a liquid outlet, the two liquid outlets of the pumps being connected respectively to the two liquid inlets of said mixer valve and said pumps being arranged so that in use they will deliver the two liquids to said mixer valve inlets at substantially equal pressures.

In accordance with another aspect of the present invention there is provided a liquid mixer valve comprising a mixing chamber which has an outlet together with a first liquid inlet and a second liquid inlet, there being also provided a slidable valve member which is disposed within said mixing chamber and which is connected to a manually rotatable control member whereby sliding movement of said valve member may be effected by rotation of the control member, said slidable valve member having a pair of spaced apertures which are respectively arranged to be brought progressively into alignment with the two liquid inlets as the rotatable control member is turned to an "on" position from an "off" position in which no parts of the two apertures of the slidable valve member are aligned with said liquid inlets, thereby preventing in said off position liquids entering the mixing chamber from both of said liquid inlets.

The apertures in said slidable valve member may each be of elongated (for example pearshaped) form and preferably where the valve is intended for use in mixing cold water and hot water the apertures are arranged so that the initial rotational movement of the rotatable control member and corresponding initial movement of the slidable valve member from the off position will result in cold water being admitted first into the mixing chamber whereafter further opening movement of said control member will have the effect of progressively introducing an increasing supply of hot water into the mixing chamber and decreasing the supply of cold water, thereby gradually increasing the temperature of the water flowing from the outlet of the mixing chamber.

Conveniently, supplies of the two liquids (such as cold water and hot water) to the liquid inlets of the mixing chamber may be effected by means of a pair of co-axial centrifugal pumps mounted at either axial end of an electric motor so as to be drivable by the motor shaft which thus extends from both opposite ends of the motor. Alternatively, said pumps may be mounted at the same end of the motor. Actuation of said motor may be controlled by a switch which is mounted in said valve and which is arranged to be switched to an on position by means engaged by said manually rotatable control member as soon as it is turned away from the off position. As a further alternative, the two pumps may be driven by two separate motors.

The invention will now be more particularly described with reference to the accompanying drawing wherein Figure 1 is a sectional elevation of one form of combined liquid mixer and pump assembly constructed in accordance with the present invention and, Figure 2 is a sectional view, taken on the line ll-ll of Fig. 1, of the liquid mixer valve seen in Fig. 1, and Figure 3 is a scrap sectional view showing in greater detail one end of the pump assembly seen in Fig. 1.

Referring to the drawings, Figs. 1 and 2 show a valve which has a housing 10 in which is mounted a mixing chamber 11. Said mixing chamber 11 has a pair of liquid inlets 1 2 and 1 3 through which can flow in use two liquids such as for example hot and cold water which are to be mixed in the mixing chamber. The mixing chamber also has a liquid outlet 1 4. As shown in Fig. 1 said liquid inlets 1 2 and 1 3 are connected respectively to the outlets 26 and 27 of two centrifugal pumps 28 and 29 which are mounted at opposite ends of the shaft 30 of an electric motor 31. Pump 28 has an inlet 32 which is connected to a supply of hot water and pump 29 has an inlet 33 connected to a supply of cold water.

The valve is also provided on the exterior of said housing 10 with a manually rotatable control member 1 5 connected to a spindle 1 6 on which is formed a pinion 1 7 which is disposed within said mixing chamber 11.

Within the mixing chamber there is also provided a slidable valve member 1 8 comprising a plate which is formed along one longitudinal edge with a rack 1 9 arranged to mesh with said pinion 1 7. Said slidable valve member 1 8 is of elongate form and it is provided with a pair of longitudinally spaced apertures 20 and 21, each of said apertures being of elongate form which, as shown, is of generally pear-shaped configuration. Furthermore as seen from Fig. 2 the narrower ends of said apertures 20 and 21 are adjacent to each other.

The slidable valve member 1 8 is disposed in the mixing chamber 11 so that it extends across the inner ends of said liquid inlets 1 2 and 1 3 and in the closed position of the valve, as shown in full lines in Fig. 2, no part of either aperture 20 or 21 registers with the inlets 1 2 and 1 3. No liquid can therefore enter the mixing chamber from either inlet 1 2 or 1 3. If however the manually rotatable control member 1 5 is turned from its off position to an on position the spindle 1 6 and pinion 1 7 will be rotated so that the interengagement of the pinion 1 7 with the rack 1 9 will result in the slidable valve member 1 8 moving towards the right from the position shown in the drawings. Where the mixer valve is intended for use in mixing hot and cold water as previously mentioned the inlet 1 3 would be connected to a supply of cold water and the inlet 1 2 to a supply of hot water and initially the larger end of the aperture 21 will be brought progressively into register with the inner end of the inlet 1 3 so that cold water alone will flow initially into the mixing chamber and thence outwardly of said chamber through the outlet 1 4. As opening of the valve continues however the smaller end of the aperture 20 will be gradually brought into register with the inner end of the liquid inlet 12 whilst the width of the aperture 21 in register with the inlet 1 3 will slowly decrease and accordingly a greater proportion of hot water will be admitted into the mixing chamber from the inlet 1 2 as opening movement of the valve by turning of the control member 1 5 continues. Finally the aperture 21 will be completely out of register with the inlet 13, as indicated by dotted lines 21 a so that the whole supply to the mixing chamber will comprise hot water. Thus when it is desired to open the valve to provide a flow of liquid from the outlet 1 4 the manually rotatable control member 1 5 can be turned to a suitable position to provide for a flow of water from the outlet at any desired temperature.

Also mounted within said housing 10 is a switch 22 having a resilient actuating member 23. One end of said actuating member 23 is bifurcated so that one part 23a engages a member 24 rotatable with the spindle 1 6 and the other part 23b is arranged to engage the button 25 of said micro-switch 22. Initially in the off position said part 23a of resilient member 23 rests in a recess formed in said member 24 and in this position the part 23b does not contact the button 25. When the member 1 5 is turned away from the off position however the initial movement of said member 24 will result in the part 23a of resilient member 23 being pushed downwardly as seen in Fig. 1 so that the part 23b will move towards the left as seen in Fig. 1 to contact and depress the button 25.Said switch 23 is connected electrically to the electric motor 31 which drives the pair of centrifugal pumps 28 and 29 mounted respectively on the two ends of the motor shaft 30 which thus extends axially from each end of the motor. Alternatively, said pumps may be mounted at the same end of said motor.

The two pumps are of similar construction and as shown in Fig. 3 each pump includes a casing 34 in which are formed (in the case of pump 29) the axially disposed inlet 33 and the radially extending outlet 27. Each pump casing contains an impeller which conveniently comprises two parts 35 and 36 made of suitable material. The part 35 comprises a hub portion 37 which is formed with an axially extending bore whereby it can be mounted on the adjacent end of the motor shaft 30, together with an annular portion 38 which carries a plurality of circumferentially spaced blades 39, said annular portion being initially connected to the hub portion by an integrai web. The other part 36 of the impeller comprises an annular backing plate having a central aperture which is arranged to fit over the external diameter of the hub portion 37 of said first mentioned part.In assembling these two parts together the annular backing plate of the part 36 is assembled over the hub portion 37 of the first part and is then welded or otherwise secured to said hub portion and the blades 39 of said annular portion of the first part whereafter the web portion of the first part 35 is trepanned out so as to leave an annular passage extending axially around the exterior of the hub portion, such annular passage then being in communication with the associated liquid inlet 33. In use, rotation of such a pump impeller will result in liquid being drawn in through the inlet 33 and then discharged radially from the impeller by the blades 39 and thence through the pump outlet 27. Thus, as previously explained when the motor 31 is actuated by opening of the rotatable control member 1 5 of the above described mixer valve, supplies of hot and cold water will be delivered from the two pumps 28 and 29 respectively to the liquid inlets 1 2 and 1 3 of the mixer valve. As a further alternative, the two pumps can be arranged so that they are driven by two separate motors.

Claims

1. A combined liquid mixer valve and pump assembly wherein said valve has a pair of liquid inlets, a mixing chamber connected to said liquid inlets and to a liquid outlet and movable control means which are adapted in use to vary the relative rates of flow of two liquids flowing through said liquid inlets into the mixing chamber and thence through the liquid outlet, and wherein said pump assembly comprises a pair of pumps each having a liquid inlet and a liquid outlet, the two liquid outlets of the pumps being connected respectively to the two liquid inlets of said mixer valve and said pump being arranged so that in use they will deliver the two liquids to said mixer valve inlets at substantially equal pressures.

2. A combined liquid mixer valve and pump assembly as claimed in Claim 1 wherein said pump assembly includes an electric motor, each of said pumps comprising a rotor mounted in a housing and the two rotors thus provided being mounted on the shaft of said motor so as in use to be rotatable thereby at the same speed.

3. A liquid mixer valve comprising a mixing chamber which has an outlet together with a first liquid inlet and a second liquid inlet, there being also provided a slidable valve member which is disposed within said mixing chamber and which is connected to a manually rotatable control member whereby sliding movement of said valve member may be effected by rotation of the control member, said slidable valve member having a pair of spaced apertures which are respectively arranged to be brought progressively into alignment with the two liquid inlets as the rotatable control member is turned to an "on" position from an "off" position in which no parts of the two apertures of the slidable valve member are aligned with said liquid inlets, thereby preventing in said off position liquids entering the mixing chamber from both of said liquid inlets.

4. A liquid mixer valve as claimed in Claim 3 wherein the apertures in said slidable valve member are each of elongated form which are so shaped that the initial rotational movement of the rotatable control member and corresponding initial movement of the slidable valve member from the off position will result in one liquid being admitted first into the mixing chamber whereafter further opening movement of said control member will have the effect of progressively introduc ing an increasing supply of the other liquid into the mixing chamber.

5. A liquid mixer valve as claimed in Claim 3 or Claim 4 wherein said apertures of the slidable valve member are each of pear shaped form, the smaller ends of said apertures being disposed adjacent to each other.

6. A liquid mixer valve as claimed in Claim 3 or Claim 4 or Claim 5 wherein there is provided an electric switch which is mov able from an open position to a closed position by said manually rotatable control mem ber when the latter is turned from its "off"

7. A liquid mixer valve substantially as hereinbefore described with reference to and as shown in Figs. 1 and 2 of the accompanying drawings.

8. A combined liquid mixer valve and pump assembly substantially as hereinbefore described with reference to and as shown in Figs. 1-3 of the accompanying drawings.