GB2301169A

GB2301169A - Liquid flow device

Info

Publication number: GB2301169A
Application number: GB9610847A
Authority: GB
Inventors: Louis Pinter
Original assignee: AQUA THERMAL CONTROLS Ltd
Current assignee: AQUA THERMAL CONTROLS Ltd
Priority date: 1995-05-23
Filing date: 1996-05-23
Publication date: 1996-11-27
Anticipated expiration: 2016-05-23
Also published as: GB9610847D0; GB2301169B; GB9510414D0

Abstract

An assembly is described which is suitable for fitting inside shower heads (hand sets), mixer taps and other hot water faucets, for reducing the flow of water when the temperature exceeds a pre-selected safe level. The assembly comprises a first means 10 responsive to temperature changes and having an aperture therein and positioned over a second means 12 having a plurality of apertures therein whereby, in use in a liquid flow line, as the liquid temperature increases, the first means closes over at least some of the apertures in the second means and, as liquid temperature decreases, the first means opens allowing liquid flow through at least some of the previously-closed apertures. One or both of the first and second means may be a temperature sensitive bi-metallic element in the form of a disc or spiral (Figure 13). The assembly may also include a pressure relief valve.

Description

LIQUID FWW DEVICE This invention relates generally to a device for controlling liquid flow relative to liquid temperature and, in particular, scalding prevention means for showers (hand sets), mixer taps and other hot water faucets; methods for their manufacture; and their use.

When using shower heads (particularly hand sets), mixer taps and other faucets where the desired temperature of the water is dependent on the correct setting of both the hot and cold water input (taps), the problem of excessively high water temperatures is frequently experienced. This usually arises from incorrectly balanced hot and cold water inputs which itself may be because of fluctuating water pressures or volumes. In addition, small water heaters suffer from the problem of the heat from the heating element dissipating into the water. Any resulting increase in the water temperature will at times cause scalding.

This problem has been previously addressed in relation to sanitary installations, in particular showers, in, for example, US patent specification no. 5 024 378. However, the solution proposed therein is to provide a valve assembly in a mixed water supply line to a tap, which valve assembly includes:: a valve seat having a cylindrical opening extending therethrough and a cylindrical valve member having slightly smaller dimensions than said valve seat opening, said valve member being movable between a closed position wherein a small radial clearance is defined between said valve seat and said valve member which allows water to leak therethrough, and an open position wherein water may freely pass between said valve member and said valve seat; an expandable, temperature-sensitive element positioned within the chamber containing the valve assembly; means connecting said expandable, temperaturesensitive element with said valve member for urging said valve member into said closed position when said temperature-sensitive element detects a temperature exceeding preselected value;; means for adjusting the position of said valve member, said adjusting means including a set screw threadably secured to said housing, and a connecting member extending between said set screw and said expandable, temperature-sensitive element; and means for resiliently urging said valve member towards the open position.

However, such a valve assembly is a complex piece of equipment, expensive and not easily put in place by an unskilled person already in possession of, for example, a shower hand set.

This invention's objective is to provide a simple, inexpensive and relatively foolproof device which may be fitted to new or existing appliances, thus eliminating the possibility of an injury arising from scalding. The invention provides an assembly suitable for fitting inside shower heads (hand sets), mixer taps and other hot water faucets, for reducing the flow of water when the temperature exceeds a pre-selected safe level.

Accordingly, the present invention provides a device for controlling liquid flow relative to liquid temperature comprising a first means responsive to temperature changes and having an aperture therein and positioned over/above a second means having a plurality of apertures therein whereby, in use in a liquid flow line, as the liquid temperature increases, the first means closes over at least some of the apertures in the second means and, as liquid temperature decreases, the first means opens allowing liquid flow through at least some of the previously-closed apertures.

Preferably, the first means is a temperaturesensitive bi-metallic element such as a temperaturesensitive bi-metallic disc or spiral. More preferably, the second means is also a temperature-sensitive bimetallic element. Conveniently, the first and second means have at least one concentric aperture. It is especially preferred that, at a predetermined liquid temperature, the first means closes to restrict liquid flow therethrough with respect to the second means while at a liquid temperature lower than the predetermined temperature, the first means is fully open with respect to the second means.

Preferably, the first means is of arcuate shape with a convex face to the liquid flow when open and with a concave face to the liquid flow when closed.

More preferably, the second means is also of arcuate shape with a concave face to the liquid flow when open and with a convex face to the liquid flow when closed.

Especially preferred is when the device is suitable for fitting into or comprised in a faucet such as a shower head, mixer tap, hot water faucet and the like.

The present invention further relates to a method of controlling liquid temperature comprising use of such a device according to this invention.

The assembly preferably comprises bi-metallic temperature-sensitive disc(s) provided with apertures designed to allow the free flow therethrough of water until the temperature of the water reaches a preselected safety point at which the bi-metallic discs invert against each other, or in an assembly using one bi-metallic disc, it inverts against an inert material provided with suitably sized and positioned apertures, thus restricting the flow of water. The direction of water flow may be either such that water flows first through the first means and subsequently through the second means (when in the open position) or vice versa.

The second means, such as the multi-aperture disc (bimetallic or inert) is preferably fitted with a pressure relief valve on the downstream side of the assembly to accommodate any surges of water pressure.

The specification of the components of the device according to the present invention, in particular the selection of the composition of the bi-metallic disc, the diameters and the aperture dimensions are designed to meet the requirements of the specific application.

With an electric hand wash unit, the rose of the outlet faucet could be designed by the manufacturer of the hand wash unit to accommodate the device. The manufacturer of a mixer tap could also incorporate in the design of the tap a suitable space downstream of the confluence of the hot and cold water flows to accommodate the device.

A further use of the device relates to electric showers wherein one or more assemblies are present to regulate the temperature of the discharged water.

Combinations of devices or assemblies according to the invention could be provided to enable multiple predetermined temperatures to be selected by the user.

Three specific embodiments of the invention have been developed to be used in different applications and will now be described by way of example with reference to the accompanying drawings in which: Figures 1 and 1A are, respectively a cross-section of the components of a first embodiment according to this invention in a free water flow position; Figures 2 and 2A are, respectively, a crosssection of the components of Figures 1 and 1A in a restricted water flow position; Figure 3 is a plan view of the bi-metallic disc of the first embodiment having a central aperture; Figures 4 and 4A are, respectively, a plan view of an inert material disc with one central aperture and radially positioned and equally spaced smaller apertures; Figure 5 is a cross-section of the device of the first embodiment in a specific shower-handset application; ; Figures 6 and 6A are, respectively, a crosssection of the components of a second embodiment according to this invention in a free water flow position; Figures 7 and 7A are, respectively, a crosssection of the components of Figure 6 in a restricted water flow position; Figure 8 is a plan view of the first bi-metallic disc of the second embodiment having a central aperture; Figures 9 and 9A are, respectively, a plan view of the second bi-metallic disc shown in Figures 6 and 6A which has a centrally positioned aperture and radially positioned and equally-spaced smaller apertures; Figure 10 is a cross-section of the components/device of the second embodiment in a specific shower hand set application;; Figures 11 and 11A are, respectively, a crosssection of the components of a third embodiment of a device according to this invention in a free watery low position; Figures 12 and 12A are, respectively, a crosssection of the components of Figures 11 and llA in a restricted water flow position; Figure 13 is a plan view of the bi-metallic disc of Figures 11 and llA; Figures 14 and 14A are, respectively, a plan view of the bi-metallic disc of the third embodiment superimposed onto the inert disc, illustrating the relative position of the bi-metallic disc strip to the holes of the inert disc; and Figure 15 is a cross-section of the device of Figure 11 in a specific shower/hand set application.

In the figures suffixed 'A', the central aperture is covered by a pressure relief valve which, in Figures 2A, 7A and 12A, is shown in the closed (solid lines) and open (broken lines) positions.

The first embodiment of the invention is a device where the flow of water is controlled by means of a bimetallic temperature sensitive disc having a central aperture. The bi-metallic disc is positioned above an inert material disc which has a number of radially positioned and equally-spaced smaller apertures.

Therefore, referring to Figures 1 to 5, a bi-metallic temperature sensitive disc (10) having a central aperture (Figure 3) is positioned to provide its convex side towards a flow of water whilst in an open position which allows water to flow through the aperture. The bi-metallic disc (10) is positioned above an inert material disc (12) and is provided with a number of radially positioned and equally spaced apertures and one central aperture (Figure 4); the central apertures of the discs (10) and (12) are concentric to allow the free flow of water in the open position of the bimetallic disc (10). Referring to Figures 1A, 2A and 4A, the central aperture is covered by a pressure relief valve (12A) comprising a metal plate having a small, central aperture to accommodate surges in water pressure. The relief valve (12A) is secured to the inert disc (12) by a rivet.

When the rising temperature of the water reaches the predetermined critical safety point, the bimetallic disc will invert (Figure 2) and restrict the flow of water to the central holes. This restricted flow of water will allow the safe discharge of the excessively hot water. Once the mix of hot and cold water has been reset to provide a flow of water with a temperature below the predetermined safety point, the bi-metallic disc (10) will revert to the open position (Figure 1). Where shown, the pressure relief valve (12A) cushions the effect of any pressure surges.

The relative positions of the discs (10) and (12) may be reversed in some applications. The device is designed to function inside the bodies of taps, shower hand sets (Figure 5) and other hot water faucets. In the specific application of the device in a shower hand set (Figure 5), the fitting will be by unscrewing the hand set (14) from the flexible hose (15); discarding manufacturers pliable washer (where fitted); and placing a new washer (11) into the flexible hose coupling (13). The inert material disc (12) with its contoured face uppermost; the bi-metallic disc (10) with its convex side uppermost and the second washer (11) are all fitted into coupling (13). Coupling (13) and hand set (14) are tightened together sufficiently to ensure the joint to be adequately watertight.

According to a second embodiment (Figures 6-10) of the present invention, there are two bi-metallic temperature sensitive discs provided (16 & 17). The discs (16 & 17) are separated by an inert material spacer (18). The first bi-metallic disc is provided with a central aperture (Figure 8). The second bi metallic disc is provided with a number of radially positioned and equally spaced smaller apertures and one central aperture (Figure 9). Referring to Figures 6A, 7A and 9A, the central aperture is covered by a pressure relief valve (17A) comprising a central plate having a small, central aperture to accommodate surges in water pressure. The relief valve (17A) is secured to the second bi-metallic disc (17) with a rivet.At a safe water temperature, the device operates with the incoming water first flowing through the bi-metallic disc having the central aperture (16), then through the second bi-metallic disc having the radially positioned apertures (17). The first bi-metallic disc (Figure 8) is positioned in the assembly to provide the convex side towards the flow of water, whilst in the open position (16). The second bi-metallic disc with the small apertures (Figure 9) is positioned in the assembly to provide the concave side towards the flow of water in the open position (17).

When the rising temperature of the water reaches the predetermined safety point, the bi-metallic discs will each invert and thereby restrict the flow of water to the central aperture of the second bi-metallic disc (Figure 7). This restricted flow of water will allow the safe discharge of the excessively hot water. Once the mix of hot and cold water has been reset to provide a flow of water with a temperature below the selected safety point, the bi-metallic discs will return to the open position (Figure 6); the pressure relief valve (17A) cushions the effect of any pressure surges.

In some applications of the device the relative position of the discs may be reversed. Pliable plastic rings (19) are provided above and below the device to ensure a watertight seal. The device is designed to function inside the bodies of taps, shower hand sets (Figure 10) and other hot water faucets. In the specific application of the device in a shower hand set (Figure 10) fitting will be by unscrewing the hand set (20) from the flexible hose (21); discarding manufacturers pliable washer (where fitted); and placing a new washer (19) into the flexible hose coupling (23). The bi-metallic disc having radially positioned apertures (17) is fitted with its concave face uppermost into coupling (23). An inert material spacer (18) is fitted into coupling (23) between the two discs; and the bi-metallic disc with the single aperture (16) is also fitted into coupling (23) with its convex side uppermost. A second washer (19) is then fitted into coupling (23). Coupling (23) is tightened to hand set (20) to ensure the joint is adequately watertight.

According to a third embodiment of the present invention there is provided a bi-metallic disc (24) provided with a strip spirally wound on a diminishing radius and having a central aperture (Figure 13).

Below the predetermined safe temperature the strip of the bi-metallic disc (24) arches away from the horizontal plane of the disc, thus providing a free flow of water through its aperture to an inert disc (25) positioned below the bi-metallic disc relative to the flow of water (Figure 11). The inert disc (25) is provided with small holes positioned spirally on a diminishing radius which coincides with the radius of the strip of the bi-metallic disc (24) (Figure 14); the inert disc is also provided with a central aperture which is concentric with that of the disc (24) (Figure 14). Referring to Figures llA, 12A and 14A, the central aperture of the inert disc (25) is covered by a pressure relief valve (25A) having a suitable aperture to accommodate surges in water pressure. The relief valve (25A) is secured to the inert disc (25) by a rivet.

When the temperature of the water reaches the predetermined safety point, the spiral strip of the bimetallic disc (24) closes down onto the inert disc (25), thus substantially limiting the flow of water to the respective small central apertures (Figure 12).

The small central apertures of the two discs (24) and (25) ensure a safe discharge of hot water having a temperature above the pre-selected safety point. Once the mix of hot and cold water has been reset to provide a flow of water with a temperature below the preselected safety point, the bi-metallic disc's spiral strip will resume the arched position away from the inert disc, and the flow of water is thereby restored (Figure 11). The pressure relief valve (25A) cushions the effect of any pressure surges.

The device is designed to function inside the bodies of taps, shower hand sets and other hot water faucets. In the specific application of the device in a shower hand set (Figure 15), fitting will be by unscrewing the handset (27) from the flexible hose (28); discarding the manufacturers pliable washer (where fitted); placing a new washer (26) into flexible hose coupling (29); fitting both the bi-metallic disc (24) with spiral strip uppermost and second washer (26) to coupling (29); and finally tightening coupling (29) to hand set (27) to ensure joint to be adequately watertight.

Claims

1. A device for controlling liquid flow relative to liquid temperature comprising a first means responsive to temperature changes and having an aperture therein and positioned over a second means having a plurality of apertures therein whereby, in use in a liquid flow line, as the liquid temperature increases, the first means closes over at least some of the apertures in the second means and, as liquid temperature decreases, the first means opens allowing liquid flow through at least some of the previously-closed apertures.

2. A device according to claim 1 wherein the first means is a temperature-sensitive bi-metallic element such as a temperature-sensitive bi-metallic disc or spiral and/or the second means is a temperaturesensitive bi-metallic element.

3. A device according to any preceding claim wherein the first and second means have at least one concentric aperture.

4. A device according to any preceding claim wherein, at a predetermined liquid temperature, the first means closes to restrict liquid flow therethrough with respect to the second means while at a liquid temperature lower than the predetermined temperature, the first means is fully open with respect to the second means.

5. A device according to any preceding claim wherein the first means is of arcuate shape with a convex face to the liquid flow when open and with a concave face to the liquid flow when closed and/or the second means is also of arcuate shape with a concave face to the liquid flow when open and with a convex face to the liquid flow when closed.

6. A device according to any preceding claim wherein its downstream side is fitted with a pressure relief valve.

7. A device according to any preceding claim which comprises bi-metallic temperature-sensitive disc(s) having apertures which allow the free flow therethrough of water until the temperature of the water reaches a pre-selected safety point at which either the bimetallic discs invert against each other or the bimetallic disc inverts against an inert material provided with suitably sized and positioned apertures, thereby restricting the flow of water.

8. A faucet such as a shower head, mixer tap, electric handwash faucet or hot water tap comprising a device according to any preceding claim.

9. A device or faucet or use thereof substantially as hereinbefore described with reference to the accompanying drawings.

10. A method of controlling liquid temperature comprising use of a device according to any of the preceding claims.