GB2214801A - Spa bath - Google Patents

Abstract

A spa bath comprises bath tub 1 provided with air injectors 3, air pump 8, and air heater 9 to supply heated air to said injectors, and heat exchanger 5, e.g. in the form of a towel rail, through which the heated air flows disposed above the tub to constitute an air break to prevent water from the filled tub flowing backwardly into the pump. The towel rail may be provided with an air bleed valve 11 to control the air pressure in the system. <IMAGE>

Description

IMPROVEMENTS IN SPA BATHS The present invention relates to improvements in spa baths. Spa baths are those wherein a current of air or other gaseous fluid bubbles up through water in a bath tub for hydrotherapeutic purposes.

Con':eit'.onal ly spa baths comprise a bath tub presided with a plurality of air injectors disposed in a spaced relation over the internal surface thereof and a air pump assembly to supply heated air via a conduit to said injectors. For aesthetic and practical reasons it is desirable to position the air pump assembly under the bath so that the conduits are as short as possible and assembly is readily effected. However, with such an arrangement it is likely that at some time water will flow back down the manifold conduit and into the air pump.

Since the air pump is usually electrically connected there is a possibility of a person within the spa bath being subjected to an electric shock. Attempts have been made to meet this problem by providing one or more non-return valves either in the manifold or at the injectors per se. This arrangement is unsatisfactory in that there can be no assurance that the oneway valves will continue to be entirely effective.

For these reasons it has been necessary to position the pump assembly well above the highest level which the water in the spa bath can achieve so as to provide a "air break" thereby to ensure the safety of the apparatus. This presents very real problems in certain situations because of the difficulty of locating the pump assembly with its associated electrical and air conduit neatly out of sight. It is particularly difficult where a bath is, for example, positioned against two exterior walls of a bathroom in which the spa bath is to be positioned since there is nowhere convenient to dispose the pump assembly.

A further attempt to deal with this problem has involved the utilisation of a specially designed grab handle for positioning in the top rim oF a spa bath Thi, grab handlc S adapted to form part of the air path to the air injectors.

Because this grab handle extends above the rim of the spa bath it can provide a air break. However the minimum space between the uppermost level of the water in the spa bath and the lowermost level of the water break is 300 mm. Extending the handle upwardly by a distance of, for example, 200 mm is not practical since it provides an impediment to the use of the bath. Further, because the heated air supplied via the conduit to the air injectors passes through such a handle, the handle will rapidly increase in temperature to a point at which it is not possible to use it for its intended purpose.

The present invention, therefore, provides a spa bath comprising a bath tub provided with a plurality of air injectors disposed in spaced relation over the internal surface thereof, an air pump assembly to supply heated air via a conduit to said injectors, characterised by the provision of a heat exchanger disposed superior to said tub and so arranged that the heated air from the air pump passes through said heat exchanger prior to reaching said injectors whereby the air pump assembly can be safely positioned inferior to the tub.

Preferably the heat exchanger is a towel rail.

The invention also provides a kit of parts for the production of a spa bath from a bath tub, the kit comprising an air pump and air heater assembly, a plurality of air injectors for positioning in said tub, and conduit ,lleans for fluid inter-conrect-on between said assembly and said injectors, characterised by a heat exchanger assembly for inter-connection between said pump and said injectors and for disposition superior to said tub.

The invention also comprises a further aspect. In spa bath assemblies in accordance with the prior art, the air pressure is raised to the required value by means of a blower and is heated via a heating element. An air bleed control valve is positioned conveniently by the side of the bath tub, said air bleed control valve being tapped into the air conduit flowing to the injectors. In order to adjust the air pressure at the injectors, the control valve is adjusted so as to bleed off excess air pressure. This arrangement, although wasteful, is necessary because otherwise an elaborate heat detecting electronic system would be necessary to relate the output of the heater to the volume of air utilised. Both the blower and the heater utilized in this arrangement have pre-set values.

A closed system for the control of both air throughput and temperature values is, in practice, expensive to achieve, and controlling only one of the parameters, for example the blower, merely results in an unwanted increase, or decrease, of air temperature at the injectors, depending on the volume of air.

The present invention also seeks to provide a means whereby the air rising from the injectors is of a desired temperature value when only the air pressure is controlled. This is achieved by positioning the air bleed valve in the heat exchanger e.g. the towel rail assembly; preferably immed;ately adjacen the air ouclet fr m the heat exchanger. It will be appreciated that an increase in air flow through the system to the air injectors will tend to transfer heat to the towel rail, or other heat exchanger, at a given value which can be readily ascertained by means of experimentation. Alternatively, if the air valve closed down so that air reaching the air injectors is that of comparatively low volume, the same amount of heat must pass through the towel rail, albeit slower.The result is that whereas there is some variation in the heat output from the heat exchanger it is within a predetermined narrow range thereby adjusting the air temperature at the air injectors to within a similar predetermined acceptable range.

The air bleed valve, when moved towards closing, will increase the pressure in the system. A pressure sensor associated with the air conduit can then be adapted to control the air pressure generated by the blower in response to the manipulation of the air bleed valve.

It will be appreciated that a constant value heater can be used in a closed system without unacceptable variations in temperature at the air injectors, a situation which has not been possible heretofore.

Accordingly, the invention is further characterised by the provision of an air bleed valve assembly operatively associated with a heat exchanger as just described and associated with a means for control of air pressure in the system.

The invention will now be described, by way of illustration only, with reference to the accompanying drawing which shows in vertical cross-section an arrangement in accordance with the invention.

A bath 1 formed of a fibreglass material is positioned on a bathroom floor and against a tiled wall in accordance with standard procedure. The bath tub 1 is provided at a plurality of equally spaced positions across its base and sides with air injectors 3 in accordance with conventional procedure. The air injectors 3 are connected to a manifold conduit shown generally at 4. A pump 8 is provided inferior to the bath tub 1. The pump 8 is connected via a conduit to an air heater 9.

A towel rail 5 is disposed on the rear rim of the bath tub 1 and secured thereto so as to extend generally perpendicular to the plane of the bath tub rim 1. The towel rail 5 is of traditional construction and is provided with two or three crossbars extending generally horizontal to the vertical plane thereof.

The lowest of said crossbars is arranged to be at least 300 mm above the level 6 of the water in the spa bath 1.

The conduit 10 extending from the air heater 9 is connected to a first side of the towel rail 5 whereas the manifold conduit 4 is connected to a second side.

Accordingly, in use, the pump 8 and the heater 9 are actuated by electrical current so as to draw air into an inlet 7, pass it through the towel rail 5 and from thence via the manifold conduit 4 and the air injectors 3 to the water in the bath tub 1. After some minutes of operation the temperature of the towel rail 5 will rise thereby airing any towels or other items of apparel disposed thereupon.

Because the towel rail 5 is set back from the bath there is no incentive to use it as a handle and, further, there is an expectation that towel rails will be hot and hence the chances of inadvertently touching a heated surface are much reduced.

Further, if there is an air bleed salve ;:, it tiay be pos} ;o!~eu at the outlet from the towel rail to the conduit 4. This air bleed valve provides means whereby the volume of air passing through the conduit and into the injectors 3 is controlled. This arrangement is preferably associated with a pressure sensor in operative interconnection with the blower 8, where the blower 8 is responsive to increases or decreases in air pressure occassioned by operation of the air bleed valve 11.

It will be appreciated that although the towel rail 5 has been shown attached to the bath it can, of course, readily be attached to a wall adjacent the bath, or at a position remote from the bath altogether so long as it is physically superior to the level 6 of the liquid in the bath tub 1.

The invention provides, therefore, a spa bath in accordance with the present invention, a kit of parts for the conversion of a bath tub to a spa bath in accordance with the present invention, and to a method for providing an air break in a spa bath such as to allow the pump assembly to be positioned inferior to the tub.

Claims (8)

1. A spa bath comprising, a bath tub provided with a plurality of air injectors disposed in spaced relation over the internal surface thereof, and an air pump assembly to supply heated air via a conduit to said injectors; characterised by the provision of a heat exchanger disposed superior to said tub to constitute an air break, arranged so that the heated air from the air pump passes through said heat exchanger prior to reaching said injectors.

2. A spa bath according to claim 1 characterised in that the heat exchanger is a towel rail.

3. A spa bath according to either of claims 1 or 2 characterised by the provision of an air bleed valve assembly operatively associated with the heat exchanger and associated with means for control of air pressure in the system; thereby to allow the control of air temperature at the injectors by controlling the air pressure in the system.

4; A kit of parts for the production of a spa bath from a bath tub, said kit comprising; an air pump and air heater assembly, a plurality of air injectors for positioning in said tub, and conduit means for fluid inter-connection between said assembly and said injectors; characterised in that a heat exchanger assembly is provided for inter-connection between said pump and said injectors and for disposition superior to said tub to constitute said air break.

5. A kit aecording to claim 4 charactised in that the heat exchanger is a towel rail.

6. A kit according to either of claims 4 or 5 characterised in that the heat exchanger is provided with an air bleed valve assembly operatively associated with the heat exchanger and associated with a means for control of air pressure in the system thereby to allow the control of air temperature at the injectors by controlling the air pressure in the system.

7. A spa bath substantially as hereinbefore set forth with reference to and/or as illustrated in the accompanying drawing.

8. A kit of parts according to claim 4 and substantially as hereinbefore set forth with reference to and/or as illustrated in the accompanying drawing.