These devices known as i. a. whirlpools, jacuzzi or bubble baths are utilised in spas and medical centers for various treatments like hydromassage and hydrotherapy. Thanks to technological progress and decreasing prices said whirlpools and hydro-treatments are coming now within reach of the average consumer.

Whirlpool systems and injectors therefor are known from the prior art to exist in different designs, see for instance the patent pubications DE-A-3715010, NL-A-1005235, US-A- 3772714, EP-A-354698 etc. g As is generally known from the current practice a whirlpool comprises a powerful pump for forcedly injecting water jets in the poolwater of the whirlpool by means of a plurality of jet heads or injectors disposed in the side walls and/or the bottom of the bathtub or pool.

In order to obtain a sparkling effect also air is injected into the water supply, such that a bubbling fluidum of water mixed with air exits the jet heads of the tub thereby creating extra whirling effects inside the water bath.

According to the state of the art the adding of air to the water may be realised in two ways: either by means of an air supply channel which runs into the water supply duct at a location immediately behind a venturi provided in the water supply duct, whereby air is sucked into the water flow, said sucked-in air being adjustable by a sniffer valve, or by means of an air supply channel fed by a ventilator which blows air under pressure into the channel and presses the air into a mixing area located at the the junction of the air channel with the water supply duct. The amount of injected air is in the latter case easier to control and this over a broader range in terms of flow rate and pressure by actuation of the ventilator motor and/or by actuation of a shut-off valve mounted in the air supply duct.

According to the known state of the art a large plurality of different injectors is needed in order to enable different kinds of whirling jet effects and hydro-massage treatments to be obtained. Said injectors comprise a stream-out or jet head that can be fixed or orientatable, e. g. rotatable jet heads, and further may be designed in various shapes and jet profiles.

A serious drawback of the state in the art directed to the provision of hydro-massage treatments with special effect, in casu therapeutic effectivity, resides in the fact that each jet head has to be serviced separately, which gives rise to prohitive expenses due to the necessary connections for plural water and/or air supply channels, incl. the provision of a plurality of control devices and adapted injector heads.

The present invention aims at avoiding said drawbacks by providing an injector element which allows by the aid of simple means, i. e. without additional costs of supplementary jet heads and connecting provisions, to create a selectively variable hydro-whirling effect and a therapeutic hydromassage of improved effectiveness.

The invention further provides a hydromassage system and a whirlpool device in which the novel injector element is integrated.

The injector element of the invention essentially comprises a hollow cylindrical bar or a tubular element of a predetermined length having closed opposing end faces, comprising a plurality of jet exit openings distributed over said length at regular interdistance, and further comprising two tubular connecting elements for connecting each end of the tubular injector element with a supply duct of a (bubble) fluidum to be injected, like water or air or a mixture of water and air.

The tubular connector element for joining the injector to a water/air supply duct is also suitable for mounting the injector element in the wall or bottom of a bubble bath or any other hydromassage pool.

According to a simples embodiment the injector element consists of a straight tubular element with a plurality of perforations which are arranged in line parallel to the longitudinal axis of the injector tube, for instance 10 holes drilled into the tube wall with equal distance to oneanother. At each of the injector tube end faces there is provided, perpendicular to the injector axis, a connecting tube portion of a given length suitable for disposing the injector element in a whirlpool tub.

Such an injector embodiment is illustrated in figure 1. It is shown that the tubular connecting portions are fixed preferably at a short distance from the injector end faces and that the jet flow-out openings are disposed preferably in the injector part located between the said connecting elements, whereby the jet opening closest to the connecting element is preferably not in tine with the axis of the fluidum supply connecting tube.

The invention is not limited to the above described embodiment. Variations of this design include i. a. non-rectilinear injectors, e. g. curved or bent tubular elements with one or more bends, possibly with helicoidal bend etc.

Forming part of the invention are also injectors with jet openings provided with various flow- out pieces or jet heads. Said jet heads may be fixedly mounted or adjustable, e. g. rotatable and/or orientatable by means of a ball joint.

Furthermore, the invention is not limited by a given shape of the injector cross section, nor by the disposition of the jet openings, nor by the shape and geometry of the injector's connecting elements or the material wherefrom the connector is made.

The cross section of the injector may be round, oval or polygonal and not necessarily remain constant over the injector length. Similar variations may apply to the connector portions of the injector, which be inclined of bent in joining the injector tube.

The jet openings not necessarily lay along a straight line and their interdistance, size and shape may be varied.

Also the material selection is not limitative: metals and alloys like copper, aluminium, brass, bronze and stainless steel are suitable and may be provided without or with a coating like chromium etc. Obviously various technical plastics suitable for sanitary applications may also be used as injector material.

It is obvious that the method of making or assembling an injector element according to the invention may differ too: for example by casting, welding, brazing, cold or warm forming, extrusion et al.

The present inventor came to the surprising finding that a tubular injector element with multiple jet openings as described above and defined in the claims, when used in a pool or bath and being supplied with water/air fluidum under pressure, gives rise to a bubbling and hydromassage effect which has never been observed before.

More in particular, it was found the jet flow intensity, hydropower or hydropressure of the fluidum in the successive jet openings is different, and specifically that the jet or hydro- pressure of the subsequent hydrojets decreased progressively from the jet opening closest to the fluidum feed-in towards the openings located downstream therefrom. Furthermore said jet pressure drop shows a regular pattern as a function of the number of openings: P1, P2, P3,...., P (n-1), Pn with n the number of jet outflow openings.

Since the injector element at the outlet side opposed to the inlet side comprises a second connecting tube for supply of water/air fluidum, the hydromassage pressure pattern over the injector length can be reversed. Herewith there is the provision of a system of alternating hydromassage: during a first time interval the fuidum supply channel connected with one end of the injector is opened and powered with forced feed of water and air (pressure air or aspirated air) while the inlet channel connected with the opposed end of the injector remains closed, such that a jet massage with decreasing intensity in the direction of the closed connection is obtained, and during a second time interval a reversed pattern of jet intensity is realised by closing the firstly openend supply channel while opening and activating the opposed injector feed connection.

The jetwhirl profile from high to low jet intensity over the injector length and vice versa is adjustable to a given extent, e. g. by changing the size, shape, interdistance and number of the jet openings.

The intensity of the imposed jet pattern and the power of the hydromassage effect obtainable by the novel injector elements can be increased or lowered by adjusting the system parameters like water flow rate and/or air pressure (or rate) separately or in combination by means of suitable components like valves and controllers/actuators.

The two opposed injector ends are thus connected to separate feed ducts of water/air supply which are independently actuatable and controllable.

A hydromassage system according to the invention comprises at least one injector element as defined hereinabove, and further a first duct for water/air supply towards one end of the injector and a second duct for water/air supply towards the other end of the injector, with the further characteristic that each supply duct is separately actuatable and closable/openable in a manner to establish a hydromassage jet pressure pattern, whereby in a first phase it exhibits a pattern from high to decreasing jet intensities and in a following phase, by closing the first supply duct and opening/actuating the second duct, it has a reversed pattern running from low jet pressures to high pressures exiting the successive injector openings.

An alternating hydromassage jet pattern is thus accomplished with only one multi-jet injector element. The two supply channels needed therefor may be branched-off from one main duct (including water pump, venturi or ventilator device for controllable air inlet) ; the supply of a water/air fluidum alternatively to a first rep. a second end portion of the injector is then realised by opening and closing of suitable control valves in the supply channels.

The hydromassage system preferably comprises an adjustable actuation control, e. g. comprising a programm unit, by which a desired hydromassage jet pattern in function of time can be established : for example the duration and frequency of the alternating jet stages, their jet intensity etc.

The realisable alternating hydromassage running over the injector length jetwise from powerful to mild and vice versa in the same direction is especially suitable for an effective massage of the lymphatic system, particularly in the lower limbs. It has been demonstrated that the lymphatic vessels react better to a alternating hydropressure pattern as obtainable by the invention, and that the vessels open quicker and drain more effectively in depth.

A whirlpool or hydromassage pool according to the invention comprises a bath tub or similar water reservoir with disposed therein at least one injector element with a hydromassage means as described above. The water reservoir may be small in volume, for instance adapted for local massage of the lower limbs.

An example of a conventional whiripool with a water/air injection supplied by means of a water pump and an air apiration channel of venturi type flowing into jet stream heads is depicted in figure 2.

An injector hydro system and bubble bath with alternating hydropressure jet pattern according to the invention is schematized in figure 3.

It may be clear that a whirlpool of the invention may be embodied in different design variants, wherein known basic components (pumps, air supplies, ducting, (magnetic) valves, multiway valves etc. ) are combinable in different desired ways accorded to application requirements, actuation, servicing and control, e. g. hydromassage systems with low up to high maximum jet stream pressure, pulsating hydrosystems and the like. With respect to servicing and control, resp. actuation use and control units, the invention is not restricted to a particular control means or system (manual operation/adjustment or electronic operation with CPU including programm for jet cycle type, intensity, time duration, pulsating in certain stages and so on).

Al these possible combinations and modifications, even those not explicitly mentioned, will be part of the invention as far as comprised in the scope of the appended claims as defined hereinbelow.