WO1997021949A1

WO1997021949A1 - Shut-off valve for hot/cold water mixing valve

Info

Publication number: WO1997021949A1
Application number: PCT/AU1996/000720
Authority: WO
Inventors: Harley A. Pizzey
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-12-11
Filing date: 1996-11-14
Publication date: 1997-06-19
Anticipated expiration: 1999-05-14
Also published as: AUPN704895A0

Abstract

A shut-off device is disclosed which is intended to be used with a single lever mixer type tap which can be manipulated by a user to provide mixed hot and cold water. The shut-off device has an inlet (41) coupling to a supply of hot water (43) and a hot water passage (54) which has an outlet (42) for coupling to the hot water inlet (18) of the single lever mixer. A valve (90) is disposed in the shut-off device for shutting off the hot water passage (54). The shut-off device has a water inlet (22) for receiving hot, cold or mixed water from the outlet of the single lever mixer and an outlet (16) for supplying water to a bath, shower or the like. A water flow passage (68, 70) extends between the water inlet (22) and the outlet (16) and a temperature sensitive expanding member (74) is arranged for sensing the temperature of water through the flow passage (68, 70) and for activating the valve (90) to close off the passage (54) if the water temperature through the flow passage reaches a predetermined temperature.

Description

SHUTOFFVALVEFORHOT/COLDWATERMIXINGVALVE

This invention relates to a shut-off device and, in particular to a modification to the shut-off device disclosed in European Patent Application No. 91119461.1 and its Australian counterpart patent No. 644,909. This

European patent, and its counterpart Australian patent, discloses a general shut-off device which, whilst specifically shown for use with separate hot and cold taps, is also applicable to other tap arrangements including single lever mixer type taps. This invention specifically relates to modifications in respect of the single lever type tap environment.

The contents of the above mentioned European patent application and its corresponding Australian counterpart patent are incorporated into this specification by this reference.

As disclosed in the above mentioned European application and corresponding Australian patent, hot and cold water is supplied to shower roses or taps via a mixing chamber in which the hot and cold water is mixed to provide water of a desired temperature. When a shower or bath is being used by a hospital patient who does not have full freedom of movement or invalid or the like, there is a possibility that if the supply of cold water is shut off, scalding water will be supplied to the shower rose or bath tap and result in serious burns to the user. It is therefore desirable to provide a shut-off device which shuts off the flow of hot water in the event that the temperature of the water exceeds a predetermined limit.

Thermostatic mixing valves are also used with the supply of water to provide some control over the temperature of water supplied to a bath or shower. Thermostatic mixing valves are specifically designed to hold a selected temperature and generally have an adjustment knob which can be manipulated to vary the temperature of water which is supplied through the valve. Whilst thermostatic mixing valves can deliver water at a specifically designated temperature they are not suitable as shut-off devices to shut off the supply of hot water when it reaches a predetermined temperature because the thermostatic mixing valve is normally provided with a control knob which can be manipulated by a user to supply water of a predetermined temperature and may therefore be set at too high a temperature and will not shut off water which is supplied at that hight temperature. Thus, thermostatic mixing valves or thermostats themselves are not generally used as shut-off devices because they are primarily intended to supply water at a desired temperature rather than to shut off water at a particular temperature. Shut-off devices are not designed to provide water at a particular temperature and temperature control is achieved by usual manipulation of the taps or faucets to which the shut-off device is connected.

The object of this invention is to provide a shut-off device which can quickly and effectively shut-off supply of hot water in the event that the temperature of the water exceeds a predetermined limit and which can quickly reset itself after shut off as in the abovementioned European application and corresponding Australian patent and which is specifically designed for use with a single lever mixer type tap.

The invention may be said to reside in a shut-off device for use with a single lever mixer type tip which can be manipulated by a user to provide mixed hot and cold water at a temperature selected by the user, the single lever mixer having a hot water inlet, a cold water inlet and an outlet for hot, cold or mixed water, said shut-off device including: a body portion, the body portion having an inlet for coupling to a supply of hot water, a hot water passage and a hot water outlet for connection with the hot water inlet of the single lever mixer; a valve member disposed in said body portion for selectively closing off the hot water passage so that in the event of closing of the valve member supply of hot water through the hot water passage is shut-off before the hot water reaches the single lever mixer; a water inlet in the body portion for receiving hot, cold or mixed water from the outlet of the single lever mixer; an outlet from the body portion; a water flow passage between the water inlet and the outlet of the body portion so that hot, cold or mixed water can flow through the shut-off device to the outlet; and temperature sensing means for sensing the temperature of water flowing through the flow passage and for activating the valve member to close the hot water passage when the temperature of the water flowing through the flow path reaches a predetermined temperature.

Thus, a user can manipulate the single lever mixer to provide hot, cold or mixed hot and cold water at a desired temperature so that the water exiting the outlet is at a desired temperature for a bath, shower or the like. In the event of the water exceeding a predetermined temperature, the temperature sensing means will cause the valve member to close to thereby shut off the hot water path so that supply of hot water is shut off upstream of the single lever mixer so that no hot water is therefore supplied to the single lever mixer. Supply of cold water to the single lever mixture continues so that the cold water is able to flow through the flow path to immediately cool the sensing means so that the device is reset in the manner described in the previously mentioned European application and Australian patent.

Preferably the valve member comprises an insert within the body portion, the insert having a reduced diameter section and a larger diameter section, the larger diameter section having a valve seat, the valve body having an outer casing portion having an inwardly projecting section so that a generally annular chamber is formed between the reduced diameter section of the insert and the inwardly projecting section of the casing, and wherein upon movement of the insert, the valve seat seats on the inwardly projecting section of the casing to shut off flow of hot water through the hot water flow path.

Preferably biasing means is arranged in the valve body for biasing the insert into a position wherein the valve seat is away from the projecting portion of the casing so that hot water can flow through the flow path.

Preferably the sensing means comprises an expansion element which expands as water temperature rises so as to force the insert against the bias of the biasing means so that the valve seat seats against the inwardly projecting portion of the casing to shut off flow of hot water through the hot water passage when the water flowing through the flow passage reaches a predetermined temperature.

Preferably the insert has a bore therethrough which forms part of the flow passage and wherein the expansion element is located in the bore in the insert.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawing which shows a cross-sectional view through a shut- off device according to the preferred embodiment of the invention. With reference to the drawing, a shut-off device 10 is shown which is specifically adapted for use with a single lever mixer 12 which includes a single lever 14 which is manipulated by a user to provide hot, cold or mixed hot and cold water to an outlet 16 of the shut-off device 10 as will be described hereinafter.

The single lever mixer 12 is of known design and therefore will not be described herein, other than to say that the single lever mixer has a hot water inlet 18, a cold water inlet 20 and an outlet 22 for providing hot, cold or mixed water from the single lever mixer 12. Suitable single lever mixers for use with the preferred embodiment of this invention are made by Frederich Grohe of West Germany.

The shut-off device 10 has an outer sleeve or pipe section 28. An outer casing 29 is arranged within the sleeve 28 and O-rings 31 seal the casing to the sleeve 28. A generally U-shaped member 34 is arranged in the upper part of the sleeve 28 and is also sealed to the sleeve 28 by 0- rings 33. The insert 34 has an inlet 30 which is in registry with the outlet 22 from the single lever mixer 12 and the member 34 is sealed to the mixer 12 by an O-ring 35.

The mixer 12 may be coupled to the shut-off device 10 by any suitable means such as by screwing the mixer 12 onto the shut-off device 10 or otherwise attaching the mixer 12 to the shut-off device 10 so that the outlet 22 is in registry with the inlet 30.

The member 34 defines an internal cavity 40 which forms a mixing chamber for continued mixing of hot and cold water from the single lever mixer 12.

The sleeve 28 and casing 29 have an inlet 41 and an outlet 42 for connection to a hot water supply 43 and a hot water pipe 44. The hot water pipe 44 supplies hot water from the outlet 42 to the hot water inlet 18 of the mixer 12.

The outer casing 29 is provided with an inwardly projecting portion 46 which has a surface 48. An insert 50 is arranged within the casing 29. The insert 50 has a reduced diameter portion 52 so that an annular chamber 54 is provided between the casing 29 and sleeve 28 and the insert 52. The insert 50 is sealed to the casing 29 by O-rings 37. Hot water is able to flow from the hot water supply 43, through inlet 41 and through chamber 54 which forms a hot water path to outlet 42 and then through pipe 44 to the mixer 18.

The insert 50 is biased downwardly in the drawing in the direction of arrow A by a spring 60, which is arranged in chamber 40 and extends between base portion 61 of member 34 and the upper surface 62 of insert 50.

Insert 50 has a bore 64 which extends from surface 62 to surface 66 and which adjacent surface 62 is in the form of a number of holes 68 which taper towards a central bore 70. The bore 70 has an enlarged diameter portion 72 and accommodates an expansion member 74 which is identical to the expansion member described in the previously mentioned European application and corresponding Australian patent.

The shut-off device 10 includes a second biasing arrangement 80 so that any over-expansion of the expansion member 74 is taken by the second biasing arrangement 80 to avoid damage to the expansion member 74. The second biasing arrangement 80 is identical in structure to the second biasing arrangement disclosed in the above mentioned European patent application and corresponding Australian patent and therefore will not be disclosed in detail herein. Reference should be made to the aforesaid European application or corresponding Australian patent for a full description of the second biasing arrangement 80.

Hot, cold or mixed water exiting the outlet 22 of the single lever mixer 12 and passing through inlet 30 into chamber 40 is able to flow through flow path 64 over the expansion member 74 to outlet 16 as shown by the arrows in the drawing. Should the temperature of the water flowing through the flow path 64 increase because of a temporary disruption to, for example, the cold water supply from inlet 20, upon reaching a predetermined temperature the expansion member 74 will expand thereby pushing against mid-section 85 of the insert 50 to push the insert 50 upwardly in the direction of arrow B against the bias of spring 60. The insert 60 has a stepped valve seat 90 at the vicinity of the reduced diameter portion 46 which can seat on surface 48 of the inwardly projecting portion 46 of outer casing 29 so that when the insert 50 is forced upwardly in the direction of arrow B due to hot water causing expansion of the expansion member 74, the valve seat 90 will seat on surface 48 to thereby shut off flow of hot water from the inlet 41 through the hot water path formed by chamber 54 so that the hot water supply to the mixer 12 is immediately and quickly shut off.

Since the device does not shut off the flow of cold water from the cold water inlet 20 through the mixer 12 to the flow passage 64, flow of cold water through the passage 64 will cool the expansion member 74 so that it contracts thereby enabling the spring 60 to bias the valve seat 90 away from surface 48 so that the device is reset quickly. Thus, since the expansion member 74 is effectively cooled by the cold water flowing through the device, it resets very quickly so that the shower or other appliance to which the device is connected can be used as soon as possible. If the water temperature remains at its normal level, the shower, bath outlet, basin outlet etc can continue in use. Should the temperature of water again rise for any reason or immediately exceed the predetermined hot water again rise for any reason or immediately exceed the predetermined hot water temperature once the hot water is again supplied through the device, the expansion member 74 will again immediately expand to cause the supply of hot water to be shut off. Once again, the cool water will cause the device to reset quickly so that the water can again be supplied unless a predetermined temperature is immediately exceeded.

As in the aforesaid European application and Australian patent, since the supply of cold water bypasses the valve 90, it ensures that the expansion member 74 is not maintained in a pool of hot water once the device has been shut off and therefore can reset quickly.

Preferably the expansion member 74 has a steep rise so that no expansion of the expansion member occurs at a temperature of say 43° or 44°C so that the flow of water through the device is not at all impaired at that temperature. However, once the temperature reaches 45°C, the expansion member fully expands so that the hot water supply is shut off in the manner described above. The steep rise of the expansion of the temperature of say 44° to 45°C thereby ensures that the device has no influence over the flow of water whilst the temperature is below the predetermined temperature, but as soon as the temperature does reach the predetermined temperature of 45°C it shuts off the supply of hot water to prevent scalding.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiments described by way of example hereinabove.

Claims

1. A shut-off device for use with a single lever mixer type tap which can be manipulated by a user to provide mixed hot and cold water at a temperature selected by the user, the single lever mixer having a hot water inlet, a cold water inlet and an outlet for hot, cold or mixed water, said shut-off device including: a body portion, the body portion having an inlet for coupling to a supply of hot water, a hot water passage and a hot water outlet for connection with the hot water inlet of the single lever mixer; a valve member disposed in said body portion for selectively closing off the hot water passage so that in the event of closing of the valve member supply of hot water through the hot water passage is shut-off before the hot water reaches the single lever mixer; a water inlet in the body portion for receiving hot, cold or mixed water from the outlet of the single lever mixer; an outlet from the body portion; a water flow passage between the water inlet and the outlet of the body portion so that hot, cold or mixed water can flow through the shut-off device to the outlet; and temperature sensing means for sensing the temperature of water flowing through the flow passage and for activating the valve member to close the hot water passage when the temperature of the water flowing through the flow path reaches a predetermined temperature.

2. The shut-off device of claim 1 wherein the valve member comprises an insert within the body portion, the insert having a reduced diameter section and a larger diameter section, the larger diameter section having a valve seat, the valve body having an outer casing portion having an inwardly projecting section so that a generally annular chamber is formed between the reduced diameter section of the insert and the inwardly projecting section of the casing, and wherein upon movement of the insert, the valve seat seats on the inwardly projecting section of the casing to shut off flow of hot water through the hot water flow path.

3. The shut-off device of claims 1 or 2 wherein biasing means is arranged in the valve body for biasing the insert into a position wherein the valve seat is away from the projecting portion of the casing so that hot water can flow through the flow path.

4. The shut-off device of claim 1 wherein the sensing means comprises an expansion element which expands as water temperature rises so as to force the insert against the bias of the biasing means so that the valve seat seats against the inwardly projecting portion of the casing to shut off flow of hot water through the hot water passage when the water flowing through the flow passage reaches a predetermined temperature.

5. The shut-off device of claim 2 wherein the insert has a bore therethrough which forms part of the flow passage and wherein the expansion element is located in the bore in the insert.