WO2015008250A2

WO2015008250A2 - Foam dispenser

Info

Publication number: WO2015008250A2
Application number: PCT/IB2014/063188
Authority: WO
Inventors: Mark Brouwer; Willy Leonard A. KEGELS
Original assignee: Airopack Technology Group B.V.
Priority date: 2013-07-17
Filing date: 2014-07-17
Publication date: 2015-01-22
Also published as: EP3022132A2; WO2015008250A3; EP3022132B1; US9790019B2; CN105377718B; US20160159556A1; CN105377718A

Abstract

A novel foam dispenser (1) is described, which comprises a dispensing container (2), a valve (7) with a downstream foaming chamber (12) and a pressure control device (3) for maintaining a constant pressure in the container (2), such that uniform and compact foam will be created.

Description

Foam dispenser

The invention is related to a foam dispenser according to the preamble of claim 1 . FIELD OF THE INVENTION

Foam dispensers for dispensing foam, like shaving-foam or hair foam and the like, from a container are used in daily life. BACKGROUND OF THE INVENTION

It is known to use a foam pump with a dip tube which is screwed on a container for foam dispensers. On the other hand aerosol containers are used with a foaming member comprising a foaming chamber with a mesh for producing the foam. Although spraying and foaming dispensers with aerosols are still in use, there are environmental reasons to use only foam pumps based on pressurized air. Since the pressure of the air created by a foam pump depends on the pumping action, the quality of the foam can differ for each pumping action. It is an object of the present invention to provide a foam dispenser which creates foam of constant quality.

This object is achieved by a foam dispenser with the features of claim 1 . In a preferred embodiment of the invention the valve comprises a valve stem and a pre-mixing chamber with orifices for entry of the pressurized gas, and a dip-tube is connected to the valve.

In another preferred embodiment the foaming chamber comprises two adjacent meshes for producing foam and an entry for mounting on the valve stem. In a further embodiment of the invention the entry of the foaming chamber has a reduced diameter with respect to the diameter of the valve stem.

In further preferred embodiment a piston with a hole is provided within the con- tainer, wherein the dip-tube is penetrating the piston through the hole.

In another embodiment of the invention the hole is sealed to the dip-tube by a sealing O-ring or by sealing lips. In another further embodiment the piston is dome-shaped.

Preferably the piston has an outer sealing ring with an upper sealing lip and a lower sealing lip. BRIEF DESCRIPTION OF THE DRAWING FIGURES

The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a foam dispenser with a container and a pressure control device,

Fig. 2 shows a second embodiment of the foam dispenser, and

Figs. 3 to 5 show the second embodiment in different positions to explain the working.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the figures the same reference numbers are assigned to the same elements, if nothing else is mentioned. In Figure 1 a foam dispenser 1 is depicted with a plastic container 2 and a pressure control device 3 as described extensively in WO-A-2005/082744, having a cup-like first cylinder 30, a piston 31 movable in a reciprocating manner within the first cylinder 30, so that a first chamber 32 is defined between the piston 31 and the first cylinder 30. Further, a high pressure container or second cylinder 33 is provided which encloses at its top the first cylinder 30 and defines a second chamber 34. A passageway 35 is leading from the second chamber 34 to the outside of the pressure control device 3 into the container 2. A valve 36 is releasing and closing the passageway 35. The first chamber 32 is filled with a gas exerting a predetermined excess pressure and the second chamber 34 is filled with a gas at a pressure higher than the predetermined excess pressure. The piston 31 has means for actuating the valve 36 dependent from the pressure difference between the first chamber 32 and the container 2, so that if the fluid pressure in the container 2 drops below the predetermined excess pressure, gas flows from the second chamber 34 to the container 2 until the container pressure approximately equals the predetermined pressure. In practice the gas is normal air.

The container 2 is closed by a bottom part 4 with a so-called Nicholson plug 5 which is provided for pressurizing the pressure control device 3. On top of the container 3 a closure 6 with a valve 7 is mounted. The valve 7 has a pre-mixing chamber 8 with orifices 9 for entry of pressurized gas or air. The valve 7 is connected to a flexible dip tube 10 which is extending in the interior of the container 2 and ending almost on top of the pressure control device 3. The valve 7 has further a valve stem 1 1 , on which a foaming chamber 12 is mounted in a sealing-fit man- ner. The foaming chamber 12 has an entry 13 which is circumventing the valve stem 1 1 . Upstream of the entry 13 a base 14 with a small bore hole 15 is provided. In the foam chamber 12 two adjacent meshes 18 and 19 are provided which create uniform compact and fine foam. Upstream of the meshes 18 and 19 an outlet 20 with a cap 21 is provided for pressing the valve 7 and so dispensing the foam. The pressure of the air filled in the pressure control device 3 is about 8 bar. The predetermined excess pressure of the air in the container 2, which is kept at a constant level by the pressure control device 3, is about 0.5 bar. Immediately over the pressure control device 3 the container 2 is filled with a fluid 25 until a prede- termined level 26. Over the fluid 25 is the pressurized air 27 which is used for propelling the fluid 25 through the valve 7 and simultaneously is forced through the orifices 9 into the pre-mixing chamber 8.

Since the fluid 25 and the air 27 are mixed at a constant pressure, the foam is created very uniformly. Further the two fine meshes 18 and 19 deliver a very compact and fine foam.

The foam dispenser 1 as described above has to be used more or less in the upright position. A freshly filled foam dispenser 1 can be held also slightly slanting. However, if the foam dispenser 1 is emptying, pressurized air can flow into the dip tube 10, so that the consistency of the foam is changing and becoming thin. On the other hand, if the completely filled foam dispenser 1 is held almost horizontally, pressurized air can also flow into the dip-tube 10, so that the foam is becoming thin.

In Figure 2 another embodiment 50 of the foam dispenser is shown, wherein the same features have the same reference numbers as in Figure 1 . Although not depicted the pre-mixing chamber 8 has also orifices 9 as in Fig. 1 . The foam dispenser 50 has a rigid dip tube 51 which is ending at a short distance to the upper end of the pressure control device 3. A dome-shaped piston 52 with a central hole 53 and a sealing O-ring 54 is circumventing the dip tube 51 . Towards the inner wall 55 of the container 2 the dome-shaped piston 52 has an outer sealing ring 56 with an upper sealing lip 57 and a lower sealing lip 58. Instead of an O-ring 54 also flexible sealing lips can be provided at the border of the central hole 53. The working of the foam dispenser 50 is shown in further details in Figures 3 to 5. In Figure 3 the cap or push button 21 is pushed slightly downwards, so that the valve 7 is opened to a small extent and gas or air will flow slowly through the dip- tube 51 . In Figure 4 the push button 21 is pushed more downwards, so that the valve 7 is opened to full extent and air 25 is flowing through the dip-tube 51 and simultaneously the dome-shaped piston 52 is pushed upwards by the excess pressure of the air 25 on the underside of the piston 52, so that also fluid 60 above piston 52 is flowing into the pre-mixing chamber 8 and foam is produced in the foaming chamber 12 and expelled through the outlet 20. If the push button 21 is released, the valve 7 is closed and no foam will flow anymore. Because of the underpressure of the fluid 27 over the piston 52, it is pushed upwards until there is again equilibrium of pressure under and above the piston 52. Figure 5 shows the new equilibrium status of the foam dispenser 50. This second embodiment 50 of the foam dispenser has the advantage that foam can be dispensed irrespective of its position, i.e. the dispenser 50 will produce foam of the same quality even if it is held upside down.

Claims

1 . Foam dispenser (1 ; 50) comprising a dispensing container (2) with a pressurized propellant gas, a valve (7) with a downstream foaming chamber (12) characterized in that a pressure control device (3) for maintaining a constant predetermined excess pressure is arranged in the dispensing container (2), said pressure control device (3) comprises a first cylinder (30) having an open end and a closed end, and a piston (31 ) movable within said first cylinder defining a first chamber (32) filled with a gas exerting said predetermined excess pressure, second cylinder (33) defining a second chamber (34), a passageway (35) from the second chamber to the outside of the device leading to the container (2), a valve (36) for releasing and closing said passageway (35), wherein the second chamber (34) being filled with a gas at a pressure higher that said predetermined excess pressure, and said piston (31 ) having means for actuating said valve dependent from the pressure difference between the first chamber (32) and the container (2), so that if the fluid pressure in the container drops below the predetermined excess pressure, gas flows from the second chamber (34) to the container (2) until the container pressure approximately equals said predetermined pressure.

2. Foam dispenser according to claim 1 , characterized in that the valve (7) comprises a valve stem (1 1 ) and a pre-mixing chamber (8) with orifices (9) for entry of the pressurized gas, and that a dip-tube (10; 51 ) is connected to the valve (7).

3. Foam dispenser according to claim 1 or 2, characterized in that the foaming chamber (12) comprises two adjacent meshes (18, 19) for producing foam and an entry (13) for mounting on the valve stem (1 1 ).

4. Foam dispenser according to claim 3, characterized in that the entry (15) of the foaming chamber (12) has a reduced diameter with respect to the diameter of the valve stem (1 1 ). Foam dispenser according to one of claims 1 to 4, characterized in that a piston (52) with a hole (53) is provided within the container (2), wherein the dip-tube (51 ) is penetrating the piston (52) through the hole (53).

Foam dispenser according to claim 5, characterized in that the hole (53) is sealed to the dip-tube (51 ) by a sealing O-ring (54) or by sealing lips.

Foam dispenser according to claim 5 or 6, characterized in that the piston (52) is dome-shaped.

Foam dispenser according to claim 7, characterized in that the piston (52) has an outer sealing ring (56) with an upper sealing lip (57) and a lower sealing lip (58).