GB2288131A

GB2288131A - Modular hot/cold water mixing device with jet pump for a mixer tap

Info

Publication number: GB2288131A
Application number: GB9504937A
Authority: GB
Inventors: Frank-Thomas Luig; Burkhard Berg
Original assignee: Friedrich Grohe Armaturenfabrik GmbH and Co; Friedrich Grohe AG
Current assignee: Grohe Water Technology AG and Co KG
Priority date: 1994-03-19
Filing date: 1995-03-10
Publication date: 1995-10-11
Anticipated expiration: 2015-03-10
Also published as: GB9504937D0; DE4409490A1; DE4409490B4; GB2288131B

Description

- 1 2288131 water mixing d vice The invention relates to a water mixing

device, and especially to such a device for use with cold water supplied at mains pipe pressure and hot water supplied at the (lower) hydrostatic pressure of an open hot water cistern.

Such a device is known from public prior use in which there is provided a chamber that is connected to the cold water supply and that feeds on the one hand a jet nozzle of a water jet pump connected to the hot water supply for delivering a specific amount of hot water.to a mixing area and feeds on the other hand a bypass that can be regulated by a valve, the mixing area having a connection to a mixed water outlet. That device is constructed, however, as a relatively bulky apparatus.

It is an object of the invention to provide an improved water mixing device.

The invention provides a water mixing device comprising a chamber which is in communication with first radial openings arranged to be connected to a first water supply and which, on the one hand, opens into a jet nozzle of a water jet pump in communication with second radial openings arranged to be connected to a second water supply for delivering a specific amount of water from the second supply to a mixing area and, on the other hand, opens into a bypass that can be regulated by means of a valve for delivering water from the first supply to the mixing area, - 2 the chamber being constructed, together with the water jet pump, the bypass, and the valve for the bypass, as a module that is mountable in a mixer tap housing having a cold -he said first water supply, a hot water supply channel as 4. water supply channel as the said second water supply, and a mixed water outlet.

It is possible to construct a water mixing device according to the invention that takes up significantly less space than the known mixing device and can be mounted as a module in tap housings.

The module advantageously has outer rqeasurements that correspond to the outer measurements of mixing valve cartridges for hot and cold pressurized water, so that the same tap housing can be used for both. As a result, firstly, the mixer tap housing can be manufactured more cheaply on account of the greater production quantities and, secondly, stock- keeping can be improved since only one tap housing is required for the two different hot water preparation systems.

Furthermore, with the construction according to the invention, a tap can be provided with which mixed water can be supplied, selectively, by means of a switching valve, to a bath tub outlet or to a shower head outlet.

one form of water mixing device constructed in accordance with the invention, and a mixer tap incorporating it, will now be described by way of example only with reference to the acccopanying drawings, in which:

A C_ h Fig. 1 Fig. 2 Fig. 3 Fig. 4 shows a water mixing device constructed as a module, in longitudinal section; shows the water mixing device according to Fig. 1 in section along the line II-II; shows the water mixing device according to Fig. 1 in section along the line III-III; shows the water mixing device according to Fig. 1, mounted in a mixer tap housing, in longitudinal section.

Referring to the drawings, one form of water mixing device is constructed in one piece as a module 2 and can be mounted as a unit in a receiving bore of a mixer tap housing 1. The module 2 can be secured in the mounted position in the mixer tap housing 1 by means of a screw thread 253, sealing being effected at the same time by means of the seals 26.

The module 2 has a module housing or body 25 of generally cylindrical shape within which is a chamber 21, arranged excentrically for reasons of space, which chamber is closed at the outer end by a valve 24. A water jet pump 22 having a jet nozzle 221 is arranged at the opposite end of the chamber 21. Radial openings 251 for letting cold water into the chamber 21 are constructed in the wall of the body 25. In the region of the water jet pump 22, radial openings 252 for letting hot water through are constructed likewise in the wall of the body 25. A radial channel 231 can be connected with or closed off from the chamber 21 by 4 means of the valve 24. The radial channel 231 opens into a -bypass 23 constructed in the body 25 in parallel with the chamber 21. The bypass 23 opens out, parallel to the outlet opening 222 of the water jet pump 22, on the end face of the body 25 away from the valve 24.

If the module 2 is mounted in the mixer tap housing as can be seen from Figure 4, the cold water enters the water mixing device via radial openings 251 and the hot water enters the water mixing device via the radial openings 252. The mixer tap housing 1 has a cold water connection 11 for connecting it to the cold water mains pipe network and a hot water connection 12 for connecting it to an open hot water cistern. The cold water from the connection 11 flows along a supply channel 110 and enters an annular chamber 16, which is arranged in the mixer tap housing 1, encircling the part of the body 25 of the module 2 through which the radial openings 251 pass. The hot water enters from the connection 12 through a return-flow preventer 121, and flows along a supply channel 120 into an annular chamber 17. The annular chamber 17 is spaced apart axially from the annular chamber 16, and encircles the part of the body 25 through which the radial openings 252 pass. The hot and cold water from the water jet pump 22 and the cold water from the bypass 23 enter a mixing area 13 in the mixer tap housing 1, from which the mixed water is released by way of a stop valve 14, into a mixed water outlet 15.

The water mixing device functions as follows:

A In the state of the device shown in Figure 4, the stop valve 14 is open and the valve 24 for the bypass 23 is also fully open. The cold water supplied from the cold water connection 11 enters the chamber 11 through the radial openings 251. Some of the cold water is released through the jet nozzle 221 of the water jet pump 22 into the mixing area 13. As the cold water passes through the jet nozzle 221, a corresponding amount of hot water is sucked through the radial openings 252, the annular chamber 17, the supply channel 120, the return-flow preventer 121 and the hot water connection 12 from the open hot water cistern and is driven, together with the cold water, through the outlet opening 222 into the mixing area 13. In parallel, cold water is pressed through the valve 24 into the radial channel 231 and from there through the bypass 23 into the mixing area 13 where it is combined with the water from the water jet pump 22 to form temperature-regulated mixed water. The temperature- regulated mixed water is released through the fully opened stop valve 14 into the mixed water outlet 15 and goes from there, for example, into a hose pipe for a hand-held shower (not shown). The coldest mixed water is produced in the water mixing device when the valve 24 is in the fully opened position. If the flow in the radial channel 231 and the bypass 23 is then restricted by closing the valve 24, the temperature of the mixed water produced in the mixing area 13 rises accordingly. When the valve 24 is completely closed, the temperature of the mixed water is raised to the highest possible level. The actual mixed water temperature can thus be adjusted over a given range by approximately mixing in cold water through the bypass 23 by means of the valve 24.

If the supply of mixed water is to be stopped, the stop valve 14 is closed. As a result of hydrostatic pressure that corresponds to the cold water pressure in the mains pipe network builds up in the mixing area 13. The cold water is prevented from overflowing into the open hot water cistern by the return-flow preventer 121. If the stop valve 14 is subsequently opened again, the mixing process resumes immediately. It is not necessary to reset the valve 24.

The stop valve 14 can be constructed advantageously as a bistable valve so that only either the fully opened position or the fully closed position is selectable.

The outer measurements of the module 2 of the water mixing device can be of such dimensions that the module can be mounted in a mixer tap housing 1 of a conventional, theremostatically-controlled mixer tap. Since the mixer tap housing 1 can therefore be manufactured in larger numbers, the device can be manufactured more cheaply. Furthermore, simpler stock- keeping is also made possible in that the module 2 of the water mixing device according to the invention or a thermostatically-controlled mixing valve cartridge can be mounted selectively in one mixer tap housing 1.

As shown in the drawings, only one channel is provided as a bypass 23. It goes without saying that there can be a plurality of bypass channels.

The jet nozzle 221 constructed in one piece with the body 25 can also be constructed as a separate piece, which, for example, can be screwed into the special housing by means of screw threads

Claims

Claims:

1. A water mixing device comprising a chamber which is in communication with first radial openings arranged to be connnected to a first water supply and which, on the one hand, opens into a jet nozzle of a water jet pump in communication with second radial openings arranged to be connected to a second water supply for delivering a specific amount of water from the second supply to a mixing area and, on the other hand, opens into a bypass that can be regulated by means of a valve for delivering water from the first supply to the mixing area, the chamber being constructed, together with the water jet pump, the bypass, and the valve for the bypass, as a module that is mountable in a mixer tap housing having a cold water supply channel as the said first water supply, a hot water supply channel as the said second water supply, and a mixed water outlet.

2. Water mixing device according to claim 1, wherein the external dimensions of the module correspond approximately to to those of mixing valve cartridges provided for mixing cold water and hot water with approximately the same supply pressures, so that either the module or the mixing valve cartridge can be mounted in the same mixer tap housing.

3. Water mixing device according to claim 1 or 2, wherein the module comprises an approximately cylindrical body, the chamber being constructed as a bore which is closed on the outer side by the valve for the bypass and Q, the bypass extending within the body as a parallel channel to the chamber, which bypass is connected to the valve by means of a radial channel.

4. Water mixing device according to claim 3, wherein the first and second radial openings in the body are constructed as bores that are arranged to lead to respective annular chambers of the mixer tap housing, which annular chambers are approximately coaxial with the body, and wherein seals are provided for sealing the two annular chambers from one another and from the exterior, when the module is mounted.

5. Water mixing device according to any one of claims 1 to 4, wherein the bypass opens out parallel to the outlet opening of the water jet pump, and wherein the bypass and the outlet opening of the pump are arranged to open out into a mixing area of the mixer tap housing, the mixing area being connected to the mixed water outlet by means of a stop valve.

6. Water mixing device according to any one of claims 1 to 5, wherein at least the valve for the bypass is provided excentrically with respect to the central axis of the module'in order to leave more space for the bypass.

7. Water mixing device according to any one of claims 1 to 6, wherein the jet nozzle can be screwed into the module.

8. Water mixing device substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

9. A mixer tap comprising a housing having first and second water inlets and a mixing area connected to a mixed water outlet; and a water mixing device as claimed in any one of claims 1 to 8 mounted in the housing with its first and second radial openings in communication with the first and second water inlets, respectively, and with the outlets from its water jet pump and its bypass opening into the mixing area.

10. A mixer tap as claimed in claim 9, wherein the water mixing device has an approximately cylindrical body and is received in a corresponding cavity in the mixer tap housing, with the valve for the bypass accessible at the outer end of the cavity.

11. A mixer tap as claimed in claim 10, comprising two annular chambers encircling the body of the water mixing device approximately co-axially therewith, the chambers being connected to the first and second water inlets, respectively, and having the first and second radial openings, respectively, of the water mixing device opening into them.

12. A mixer tap as claimed in any one of claims 9 to 11, wherein the mixing area is connected to the mixed water outlet through a stop valve.

13. A mixer tap as claimed in any one of claims 9 to 12, comprising a reverse flow prevention means in its second water inlet.

14. A mixer tap substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

15. A water supply system comprising a mixer tap as claimed in any one of claims 9 to 14 with its first and second water inlets connected to first and second water supplies, respectively, wherein the normal supply pressure of the first water supply is greater than that of the second water supply.

16. A water supply system as claimed in claim 15, wherein the first water supply is at mains.pressure.

17. A water supply system as claimed in claim 15 or claim 16, wherein the second water supply is at the pressure of an open cistern.

18. A water supply system as claimed in any one of claims 15 to 17, wherein the first water supply is arranged to supply cold water and the second water supply is arranged to supply hot water.