The present invention relates to a foam generating device and particularly but not exclusively, to a device for generating foam in bath water.

When preparing a bath tub with water and bubble bath, the bubble bath is typically poured into the bath water and the water is then agitated by a user to mix the bubble bath with the water to create a foam. Alternatively, the bubble bath is poured near the fall of water from a bath tap so that the fall of water helps to mix the bubble bath with the water to produce the foam.

The practice of mixing bubble bath with the bath water is popular for personal bathing because the bubble bath provides a pleasant odour and the foam serves to insulate the bath water, keeping it warm for longer. In addition, the foam helps to reduce the build-up of deposits on the bath tub at and below the water level. However, it is found that an excessive amount of bubble bath is often used in providing the desired amount of foam, since it is difficult to maximise the foaming ability of the bubble bath.

I have now devised a foam generating device which provides for an increased amount of foam per unit volume of bubble bath, when compared with conventional techniques.

In accordance with the present invention, there is provided a foam generating device, the device comprising a housing which is arranged to receive a foaming agent, the housing comprising a piston section having a piston disposed therein, and a mixing section arranged in fluid communication with the piston section,

the piston being arranged to move in a first direction within the piston section to provide a compression stroke, in which a mixture of air and foaming agent within the mixing section becomes compressed and forced through an outlet, and a second direction within the piston section to provide a recovery stroke, in which a mixture of air and foaming agent are drawn into the mixing section.

The device thus provides an improved aeration of the foaming agent by forcing a compressed mixture of air and foaming agent through a narrow outlet. Preferably, the piston comprises a member which is reconfigurable between a first configuration in which the member forms a seal within the piston section during the compressions stroke and a second configuration in which a mixture of air and foaming agent is permitted to pass from the piston section into the mixing section past the member.

The piston preferably further comprises an arm which is coupled at one end to the member and at the other end to a cap which is arranged to cover the open periphery of the piston section at the end of the compression stroke.

The foaming agent preferably acts to seal the member to the piston section of the housing during the compression stroke.

Preferably, the outlet is disposed within a wall of the housing which forms part of the mixing section. The device preferably comprises a plurality of outlets.

Preferably, the or each outlet comprises a one-way valve disposed therein.

The or each outlet is preferably positioned upon the device such that the or each outlet is submersed within liquid during use, for example within bath water. Preferably, at least a portion of the piston section is arranged to extend out of the liquid.

The piston section and mixing section of the housing are preferably substantially cylindrical in shape and the mixing section preferably comprises a greater diameter than the piston section.

Preferably, the piston section comprises an open upper periphery for receiving the foaming agent, such as bubble bath. The device is preferably further arranged to draw liquid, for example bath water, into the mixing section during the recovery stroke, so that the foaming agent and air mix with the liquid before passing out of the mixing section through the or each outlet during the compression stroke. An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is perspective view of a toy comprising a foam generating device according to an embodiment of the present invention illustrated in outline, with the piston arranged near the end of a compression stroke;

Figure 2 is perspective view of the toy of figure 1 with the piston arranged near the end of a recovery stroke; and,

Figure 3 is a side view of the toy of figure 1 in a bath tub, during a compression stroke.

Referring to figures 1 and 2 of the drawings, there is illustrated a foam generating device 10 according to an embodiment of the present invention. The device 10 is illustrated as being embodied within a toy monster so that the device 10 may appeal to children and encourage them to use the bath. However, it is to be appreciated that the device 10 may be embodied in other designs.

The device 10 comprises a housing 1 1 having a piston section 12 and a mixing section 13 which comprise substantially cylindrical side walls and which are arranged in fluid communication with each other. The piston section 12 comprises a smaller diameter than the mixing section 13 and is orientated upon the mixing section such that a longitudinal axis of the piston section 12 and a longitudinal axis of the mixing section 13 are substantially collinear.

The piston section 12 is sealed to the mixing section 13 by a flange 14 which extends around a lower portion of the piston section 12 in sealing relation therewith, and which extends substantially radially outwardly of the piston section 12. The flange 14 terminates at the inner periphery of the mixing section 13 at an upper region thereof and is sealed thereto. Accordingly, the lower region of the piston section 12 is arranged to open into an upper region of the mixing section 13.

The side walls of the piston section 12 extend from the flange 14 and terminate at an open upper periphery thereof 15. The side walls of the mixing section 13 however, extend downwardly from the flange 14 and terminate at a base plate 16 which serves to close the bottom of the mixing section 13 and thus the housing 11 .

The piston section 12 comprises a piston 17 disposed therein, which is arranged to move back and forth along the piston section 12. The piston 17 comprises an arm 18 which extends substantially along the axis of the piston section 12 and is sized to substantially correspond with the length of the piston section 12. A lower end of the arm 18 is coupled to the centre of a disc 19. The disc 19 is orientated substantially perpendicularly to the arm 18 and comprises a deformable rim 20 which extends around the periphery of the disc 19. An upper end of the arm 18 is coupled to the centre of a cover 21 which is arranged to close the open upper periphery 15 of the piston section 12 and thus the housing 1 1.

According to a first embodiment of the present invention, the foam generating device 10 further comprises at least one aperture 22 formed in the side wall thereof proximate to the base plate 16. Referring to figure 3 of the drawings, in use, the mixing section 13 is submersed in bath water 23 and the upper periphery 15 of the piston section 12 is arranged to extend above the water surface 24. A user (not shown) then pulls upwardly on the piston arm 18; during this movement, the restricted opening of the at least one aperture 22 create a low pressure within the mixing section 13 and so the deformable rim 20 on the disc 19 is deformed downwardly toward the mixing section 13, away from the side walls of the piston section 12, causing air to pass into the piston section 12 through the open periphery 15 thereof and into the mixing section 13, past the disc 19. At the same time, bath water 23 becomes drawn into the mixing section 13 through the at least one aperture 22 formed in the side wall of the mixing section 13.

Once the arm 18 has been suitably raised, the user (not shown) can then pour a volume of foaming agent, namely bubble bath (not shown) into the portion of the piston section 12 that extends above the disc 19, through the open periphery 15 of the piston section 12, so as to charge the device 10 with the bubble bath (not shown). The user (not shown) then pushes the arm 18 into the piston section 12 to cause the disc 19 to move along the piston section 12 toward the mixing section 13, to generate a compression stroke. During this movement, the water 23 and air (not shown) in the mixing section 13 become compressed and the increased pressure in the mixing section 13 causes the rim 20 on the disc 19 to move outwardly to seal against the side walls of the piston section 12. Accordingly, as the disc 19 moves along the piston section 12, the increased pressure in the mixing section 13 causes the mixture of air (not shown) and water 24 therein to pass out through the at least one aperture 22. The cover 21 on the arm 18 is arranged to abut the upper open periphery 15 of the piston section 12 at the end of the compression stroke to limit the movement of the piston 17 within the piston section 12 and to close the housing 10.

The user (not shown) then subsequently pulls the arm 18 upwardly once again and during this recovery stroke, the disc rim 20 deforms again downwardly toward the mixing section 13, away from the side walls of the piston section 12, thereby causing a mixture of air (not shown) and the bubble bath (not shown) disposed above the disc 19 to pass into the mixing section 13 past the disc 19. Similarly, at the same time, bath water 23 becomes drawn into the mixing section 13 through the at least one aperture 22 formed in the side wall of the mixing section 13. During the subsequent compression stroke, the air (not shown), water 23 and bubble bath (not shown) within the mixing section 13 become agitated and mixed, and forced out through the at least one aperture 22 creating a foam 25 within the bath water 23. The recovery and compression strokes can then be repeated to create more foam 25 and more bubble bath (not shown) can be introduced into the piston section, if required, at the end of a recovery stroke.

As the bubble bath (not shown) passes into the mixing section 13 past the disc 19 during the recovery stroke, it is found that the bubble bath (not shown) lubricates the internal face of the side walls of the piston section 12, and the disc rim 20, thereby facilitating the sealing of the rim 20 to the side walls during the compression stroke and a smooth movement of the piston 17 within the piston section 12.

According to a second embodiment of the present invention which is not illustrated, the at least one aperture 22 comprises a one way valve (not shown) disposed therein which prevents bath water 23 entering the mixing section 13 during the recovery stroke. On the compression stroke however, the bubble bath (not shown) and air (not shown) become mixed and forced out through the valves (not shown) to create the required foam 25.