GB2202033A

GB2202033A - Anti-scald device

Info

Publication number: GB2202033A
Application number: GB08729271A
Authority: GB
Inventors: Peter J Dean
Original assignee: Triton PLC
Current assignee: Triton PLC
Priority date: 1986-12-24
Filing date: 1987-12-15
Publication date: 1988-09-14
Also published as: GB8729271D0

Abstract

A system for providing hot water to a shower comprises a means for heating the water such as an adjustable hot/cold water mixing valve, supplying the heated water to a shower head and a device positioned within the supply and adjacent the shower head to interrupt the water supply in the event that the temperature exceeds a predetermined limit, the device consisting of a body containing a chamber 100 with an inlet 4 for the heated water and an outlet 8 to the shower head; a valve member 10 adapted to close the inlet/or outlet against a spring bias 20, the closing of the valve member being controlled by the expansion of a temperature responsive device 30 contained within the chamber. The valve member 10 may include a bypass slot 13. <IMAGE>

Description

ANTI-SCALD VALVE Mle present invention relates to a valve which can be attached to the outlet end of a domestic hot water supply unit, especially a shower head, for interrupting the flow of water through the outlet in the event that its temperature exceeds a predetermined limit.

Valves and taps that mix hot and cold water from separate supplies are in wide use in households, especially for supply of water at an acceptable temperature to a shower head orakitchen sink. thany mixing valves incorporate a temperature responsive device, e.g: a thermostat to ensure that the temperature of the water leaving the device is that required by the user. However, a non-thermostatically controlled mixing device may be inadvertently adjusted such that the outlet temperature of the mixed hot and cold (fed tank supplies) be excessive, i.e. so as to cause scalding. In circumstances where such a possibility exists there is a need to ensure that the supply to the user will be interrupted if the water temperature exceeds a maximum predetermined limit.

We have now developed a valve that can be secured to a hot water supply outlet, e.g. the outlet sid of a hot/cold water mixing valve and preferably adjacent the outlet point, for example a shower headand which will act to interrupt the water supply to the outlet when the temperature of that supply exceeds a predetermined limit.

Mle present invention therefore provides a domestic water heating system comprising means to heat a water supply, said means including an outlet for heated water to a point of use and further including means communicating with the outlet point at or adjacent the point of use for interrupting the supply of water to the point of use when it exceeds a predetermined temperature, said means consisting of a valve including a body having inlet and outlet ports, the inlet port being suitable for attachment to, at or within the outlet pipe of a hot water supply, a chamber contained within the body and communicating with the said inlet and outlet ports via respective inlet and outlet passageways, a valve member positioned within the chamber for movement therein and including at one end a face portion dimensioned to co-operate with a corresponding valve seat positioned at the end of the inlet passageway, means resiliently urging the valve away from the valve seat, and means at the other end of said valve member co-operating with a temperature responsive device located within the chamber and secured against movement in a direction away from said inlet passageway, whereby when the temperature of water entering the chanll,er exceeds a predetermined limit, the temperature responsive device acts to urge the valve member towards the said inlet passageway and to cause the valve face to engage the corresponding seat to close the said inlet passageway and to interrupt the supply of water to the outlet.

Xle hot water supply may be provided by a valve designed to mix supplies of hot and cold water by adjustably proportioning the supplies into a mixing chamber by variable amounts to vary the outlet temperature of the mixed liquids.

Preferably the valve member includes a bypass passageway to allow a limited volume of water to pass through the valve member when the inlet passageway is closed, thereby avoiding an undesirable build up of back pressure behind the valve.

One embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic representation of a section through a valve of the present invention; Figure 2 is a section through A-A Fig.1; Figure 3 is a section through WB Fig.1.

The valve illustrated in Figs 1 - 3 of the drawings is intended to be secured to the outlet end of a domestic supply pipe to a domestic shower head, the shower head then being secured directly to the lower end of the valve.

A hollow body 1 defines a chamber 100 having, at the lower end, an outlet passageway7leading to an outlet 8, the external portion of the passageway 7 being screw threaded to receive a conventional shower head. The upper end 101 of body 1 is closed by a cap 2 in screw threaded engagement therewith and containing shoulders 201 which engage shoulders 102 of upper portion 101 via a sealing gasket 103.

Cap 2 includes an inlet 4 having a screw threaded portion 3 for engagement with a correspondingly screw threaded end portion of a supply pipe. Inlet 4 communicated with chamber 100 via inlet passageway 5 defined by a downwardly extending annular portion 22 spaced from the walls of chamber 100 to provide shoulder 21 at the upper end thereof. An annular valve seat 6 is formed at the lower end of portion 22.

A valving member is located for axial movement within chamber 100 and consists of an inverted cup-shaped body member 10, having a lip forming a shoulder 11 that is in sliding engagement with the inner walls of the body 1. A valve face 14 is formed on the upper side of body 10 for co-operation with valve seat 6 at the end of portion 22 of cap 2. Water passageways 12 are provided in body 10 of the valving member 14 to allow water to pass from the inlet 5 into the lower end of chamber 100. A bypass slot 13 is formed adjacent of one of the water passageways 12 to permit a limited flow of water to pass the valving member when the valve face 14 is in engagement with valve seat 6. Axial passageway 16 formed in body 10 screw-threadedly receives a member 15 which extends upwardly through body 10 and downwardly into chamber 100.A lock nut 17 engages the upper threaded end of member 15 and determines the position of member 15 relative to valving member body 10.

A thermo-responsive device 30 is positioned in the lower end of chamber 100 and located on shoulders 33 of guide members 32 extending inwardly of the wall of body 1. Axial passageway 31 formed in device 30 receives downwardly depending member 15 from valving member body 10, member 15 engaging the bottom of the passageway 31 when the valve is in the fully open position.

A coiled spring 20, acting between shoulders 11 of valving member body 10 and shoulders 21 of inlet cap 2, urges the valving member away from the inlet to the extent permitted by downwardly depending member 15. In use, water from a mixer valve enters the valve through inlet 4 and passageway 5, flows past the valving member via passageways 12 into the lower end of chamber 100 and around temperature responsive device 30 before leaving the valve passageway 7 and outlet 8. In the event that the temperature of the water from the mixing valve increases significantly the temperature responsive device 30 expands, causing member 15 to urge valving member body 10 upwardly against spring 20.As the temperature increases the temperature responsive device expands further until ultimately valve face 14 engages valve seat 6 to interrupt the supply of water from the supply into chamber 100, apart from a limited volume which passes through bypass slot in valve body 10.

The temperature at which the valve face and valve seat engage can be adjusted by varying the relative positions of the valving member and inlet. This is achieved by removi.n lock nut 17 and inserting a screwdriver into slot 18 formed in the top of member 15 to move the valve body 10 upwardly or downwardly within chamber 100 to lower or raise the temperature at which the supply will be interrupted.

Although the invention has been described with reference to a device for attachment to a shower installation, it is equally effective at the outlet of any hot water supply system, e.g.: it may be fitted within a shower hand set, within a flexible hose, or at the outlet of a mixer valve.

Claims

CLAIMS:

1. A domestic water heating system comprising means to heat the water and to supply the heated water to an outlet at a point of use, and a device communicating with the outlet at or adjacent the point of use for interrupting the supply of water thereto when it exceeds a predetermined temperature, said device consisting of a body having inlet and outlet ports, the inlet port being suitable for attachment at or within the outlet of the hot water supply, a chamber contained within the body and communicating with the said inlet and outlet ports via respective inlet and outlet passageways, a valve member positioned within the chamber for movement therein and including at one end a face portion dimensioned to co-operate with a corresponding valve seat positioned at the end of one of the inlet or outlet passageways, means resiliently urging the valve away from the valve seat and means at the other end of the said valve member co-operating with a temperature responsive device located within the chamber and secured against movement in a direction away from the said one passegeway, wherebu when the temperature of water enterilsg the chamber exceeds a predetermined limit, the temperature responsive device acts to urge the valve member towards the said one passageway and to cause the valve face to engage the corresponding seat to close the said passageway and interrupt the supply of water to the outlet.

2. A valve according to claim 1 wherein the valve member includes a bypass passageway to allow a limited volume of water to pass the valve member when the inlet passageway is closed.

3. A valve according to claim 1 or claim 2 wherein the hot water supply to the outlet is provided by an adjustable hot/cold water mixing valve.

Ll. A valve substantially as herein described with reference to the drawings.