WO2009116858A1

WO2009116858A1 - Power-driven device for dosed dispensing of a fluid and foaming means for use therein

Info

Publication number: WO2009116858A1
Application number: PCT/NL2009/000066
Authority: WO
Inventors: Wilhelmus Johannes Joseph Maas; Petrus Lambertus Wilhelmus Hurkmans
Original assignee: Dispensing Technologies B.V.
Priority date: 2008-03-19
Filing date: 2009-03-19
Publication date: 2009-09-24

Abstract

The invention relates to a device (1) for dosed dispensing of a fluid. This dosing device (2) comprises a container for the fluid which is connected to an outflow channel (3). The outflow channel (3) debouches in a dispensing opening (4). According to a first aspect of the invention, the device further (1) comprises means (8) for pressing the fluid out of the container (2) to the outflow channel (3). These pressing means (8) are driven by a power source (6) and adapted to place the interior of the container (2) under pressure. The dosing device (1) further comprises controllable primary closing means (7) for closing or leaving clear the outflow channel (3) as desired. The pressing means (8) can comprise an air pump and the power source (6) can be an electric motor (6) powered by a battery (26). According to another aspect of the invention, the dosing device is provided with means (39) for forming a foam which can comprise a movable grid (41) placed in front of the outflow channel (4).

Description

Enclosure to letter dated 18 May 2009

POWER-DRIVEN DEVICE FOR DOSED DISPENSING OF A FLUID AND FOAMING MEANS FOR USE THEREIN

The invention relates to a device for dosed dispensing of a fluid, comprising at least one container for the fluid, which is connected to at least one outflow channel which debouches in a dispensing opening, and means for pressing the fluid out of the container to the outflow channel. Such a dosing device is generally known and is applied particularly for the purpose of dispensing precisely determined quantities of a liquid cleaning agent.

In most known dosing devices, which are also referred to as trigger sprayers, the pressing means are formed by a pump which is operated by pulling a trigger. The pump is here usually a piston pump, the piston of which is directly connected to the trigger. Dosing devices are however also known wherein the pump is driven by a power source, for instance an electric motor. Use is then often likewise made herein of a piston pump, which is operated via an eccentric when the electric motor is switched on by pressing the trigger.

The operation of the trigger sprayers, be they manually operated or electrically driven, is as follows. The pump draws the fluid for dosing out of the container, brings it under a higher pressure and then delivers it to the outflow channel. From there the fluid is sprayed out with force through the dispensing opening. The fluid can be dispensed in the form of a jet, although an appropriate design of the dispensing opening also often provides the option of dispensing the fluid in the form of a fine spray mist. A pump pressure in the order of 6 to 8 bar is usually required for this purpose. In addition, the option is sometimes provided of dispensing the fluid as a foam. Additional measures are generally required here to enable admixture of sufficient air with the fluid for dispensing in order to form a foam.

The most significant drawback of the known dosing devices with power-driven pump is that they wear quite quickly due to the continuous contact with the fluid for dispensing which, as stated, will often be a cleaning liquid. Such fluids are after all by their very nature rather aggressive. The known driven dosing devices therefore usually have poor reliability and a limited lifespan. In addition, dosing devices suitable for dispensing foam have the drawback that they are often more complicated, and thus more expensive, than conventional devices. Finally, the known dosing devices have the drawback that the dispensing of the fluid often progresses unevenly as a result of the pulsating nature of the piston pump.

The invention now has for its object to provide a dosing device of the above discussed type, wherein the stated drawbacks do not occur.

According to a first aspect of the invention, this is achieved in such a dosing device in that the pressing means are driven by a power source and adapted to place the interior of the container under pressure, and the device further comprises controllable primary closing means for closing or leaving clear the outflow channel as desired. By thus not using the pressing means to pump the fluid out of the container to the outflow channel, but instead to only place the container under pressure, after which the fluid can be dispensed by actuating the primary closing means, the pressing means no longer come into direct contact with the fluid. Impairment of the pressing means is hereby avoided so that reliability is improved and the lifespan increased.

The optimum value of the pressure in the container depends on the application. In a preferred embodiment of the dosing device the pressing means are adapted to place the interior of the container under a pressure of less than 1 bar, preferably 0.1 to 0.7 bar, more preferably 0.2 to 0.6 bar, and most preferably 0.3 to 0.4 bar. As a result of the use of such low pressures no special structural measures are necessary in the manufacture of the container and the dosing device .

The pressing means preferably comprise at least one air pump with a suction side and a pressure side, wherein the suction side of the pump is connected to the atmosphere and the pressure side to the interior of the container. Air can thus be simply drawn in from the atmosphere in order to place the container under pressure.

The air pump is preferably a non-pulsating pump, in particular a swash plate pump or a displacement pump. The fluid can thus be dispensed very uniformly.

When the pressure side of the pump is further connected to the outflow channel, the air brought under pressure by the pump can also be used for mixing with the fluid for dispensing. A fluid/air mixture is thus obtained which can form the basis for a spray mist or foam.

This can be achieved in structurally simple manner when the connection between the pressure side of the pump and the outflow channel runs through the interior of the container. The connection between the pressure side of the pump and the outflow channel preferably comprises an air conduit which debouches close to the dispensing opening. Admixture of the air thus takes place only at the moment that the fluid leaves the dosing device, whereby the effect thereof is maximal. A fine spray mist or an airy foam can hereby be formed at considerably lower pressures than heretofore usual . When the outflow channel and the air conduit herein run concentrically at least close to the dispensing opening, the air and the fluid can be brought together in radial direction, thereby achieving an optimal mixing. The outflow channel can, as desired, here be annular and enclose the air conduit, or the air conduit can be annular and be arranged around the outflow channel.

In order to enable accurate admixing of the correct amount of air with the fluid the dosing device is preferably provided with controllable secondary closing means for closing or leaving clear the connection between the pressure side of the pump and the outflow channel as desired.

When the primary closing means are adapted to leave clear the outflow channel when the pressing means are operative, the fluid can be dispensed immediately once it is has been brought under pressure. The container hereby does not have to function for an extended period of time as pressure vessel, so that the loads on the construction and the seals are minimal. In order to then be able to simultaneously mix air with the fluid it is recommended that the secondary closing means are adapted to leave clear the connection between the pressure side of the pump and the outflow channel when the pressing means are operative. The simultaneous operation of the primary and secondary closing means has the advantage that the mixing ratio of the fluid and the air is constant and is determined only by the ratio of the throughflow surfaces of the outflow channel and the air conduit. The coordination of the operation of the different components can be achieved in relatively simple manner when the dosing device is provided with a central control member connected to the primary and/or secondary closing means and the power source of the pressing means .

A compact, quiet and reliable embodiment of the dosing device is achieved when the power source is an electric motor powered by at least one battery. In a dosing device for domestic use it is then possible to suffice with for instance two AA. batteries powering a 3V electric motor. When the container has a neck, the electric motor and the battery are preferably arranged in or on the neck. A compact construction is thus achieved, which is no bigger, or hardly so, than a conventional manually operated trigger sprayer. Furthermore, the design of the container thus requires no or hardly any modification, so that the dosing device is also suitable for combining with different containers .

With a view to assembly, it is recommended here that the electric motor and the pump are structurally integrated.

According to a second aspect of the invention, a dosing device is provided which is provided with means placed in front of the outflow channel for the purpose of forming a foam. By incorporating such foaming means in front of the outflow channel, i.e. at the position of the dispensing opening, a high-quality foam can thus be formed in simple manner without considerable structural modifications to the dosing device being necessary for this purpose.

When the device is intended for dispensing a fluid/air mixture, the foaming means preferably comprise at least one grid. A very fine and homogenous form is formed by urging the exiting fluid/air mixture through a grid. Although such a grid is per se known, it is now found, particularly in the case of a fluid/air mixture, to produce remarkably good results . In order to enable use of the dosing device for dispensing the fluid in different forms, the foaming means are preferably movable between an operative position, in which they are placed in front of the outflow channel, and a rest position in which they leave the outflow channel clear. This can be achieved in structurally simple manner when the foaming means are pivotable around an axis running substantially transversely of the direction of the outflow channel .

Finally, the invention also relates to foaming means intended for application in a dosing device as described above .

The invention is elucidated hereinbelow on the basis of a number of embodiments, wherein reference is made to the accompanying drawing, in which corresponding components are designated with the same reference numerals, and in which:

Fig. 1 is a perspective view of a dosing device according to the invention,

Fig. 2 is a perspective longitudinal section through the dosing device of fig. 1,

Fig. 3 is a partly transparent perspective view of the upper part of the dosing device of fig. 1 and 2 showing the flow of air and fluid,

Fig. 4 is a partly cut-away perspective view of the upper part of the dosing device, in which the air conduit is indicated, Fig. 5 is a partly cut-away perspective view from a different angle than fig. 4, in which the fluid channel is indicated,

Pig. 6 shows a longitudinal section through the dosing device at the position of the outflow channel and the dispensing opening,

Pig. 7 is a detail view on enlarged scale as according to arrow VII in fig. 6,

Fig. 8 is a perspective view of the dispensing opening with the foaming means in their rest position, and

Fig. 9 shows a view corresponding to fig. 8 of the foaming means in their operative position.

A device 1 for dosed dispensing of a fluid F comprises a container 2, here in the form of a plastic bottle, which has a neck 9 (fig. 1) . A dosing head 10 is arranged on this neck 9, for instance by means of a threaded ring 17 which is screwed onto external screw thread 18 on neck 9. Outflow channel 3, which debouches into a dispensing opening 4, is formed in this dosing head 10. The interior of container 2 is connected to this outflow channel 3. A trigger 11 and a slide lock 12 are arranged under dispensing opening 4.

Dosing device 1 further comprises means 5 for pressing fluid F from container 2 to outflow channel 3. According to the invention these pressing means 5 are driven by a power source 6 and are adapted to bring the interior of container 2 under pressure. The value of the pressure in the container depends on the application. For optimal atomization or foaming use is made in the shown example of a lower limit of 0.25 bar. In order to avoid extra structural measures as far as possible the upper limit for the pressure is set here at 0.4 bar. In this case it is possible to suffice with a normal, thin-walled plastic container of freely chosen shape. When considerably higher pressures are used, both the shape and the wall thickness, or even the material, of container 2 must be modified.

Power source 6 is here a 3V electric motor which is powered by one or more batteries 26, in the shown embodiment two AA batteries . Electric motor 6 is here accommodated in a liquid-tight housing 16 arranged in neck 9 (fig. 2) and which forms the bottom part of dosing head 10. Batteries 26 are arranged in two spaces 27 on the top side of dosing head 10 on either side of outflow channel 3.

Pressing means 5 here comprise an air pump 8 which is structurally integrated with electric motor 6 and also accommodated in housing 16. Air pump 8 is of a non-pulsating type, for instance a displacement pump or a swash plate pump. A uniform spray pattern is hereby obtained without the discontinuities at the beginning and end of a pump stroke which occur with the use of a piston pump.

Air pump 8 has a suction side S and an pressure side P. Suction side S is here connected to the atmosphere while pressure side P is connected to the interior of container 2. Connected for this purpose to pressure side P of air pump 8 is a tube bend 13 which leads to an upward directed channel 14 adjacently of air pump 8. At the top this channel 14 debouches via an opening 15 into neck 9. A connection is thus realized between pump 8 and the interior of container 2, whereby the interior can be brought under pressure and fluid F can be urged therefrom. The connection is embodied here such that it simultaneously serves as liquid seal, thereby preventing direct contact between fluid F in container 2 and pump 8.

Dosing device 1 according to the invention further comprises controllable primary closing means 7 for closing or leaving clear outflow channel 3 as desired. These primary closing means 7 are formed here by a piston which is received slidably in a chamber 19 (fig. 5) . This chamber 19 forms part of a fluid conduit which runs from the interior of container 2 to outflow channel 3 and which further comprises a dip tube 20, a first vertical channel segment 21 leading to chamber 19 and a second vertical channel segment 22 leading from chamber 19 to outflow channel 3 (fig. 6) . Piston 7 is provided with two sealing rings 23 and is movable between a closed position, in which sealing rings 23 are situated on either side of an inflow opening 24 of chamber 19, and an open position as shown in fig. 5, in which sealing rings 23 are retracted to such an extent that inflow opening 24 is left clear. In this position the fluid can flow through chamber 19 to outflow opening 25 and from there to outflow channel 3.

Pressure side P of air pump 8 is connected not only to the interior of container 2 in order to place the fluid F therein under pressure, but also to outflow channel 3 in order to be able to admix air A into the outflowing fluid F. In the shown embodiment this connection between pressure side P and outflow channel 3 runs through the interior of container 2 and comprises an air conduit which debouches close to dispensing opening 4. This air conduit comprises a first vertical channel segment 28 (fig. 4) , a chamber 29 connecting thereto and lying adjacently of chamber 19 of the fluid conduit, a second channel segment 30 extending vertically from chamber 29 and a horizontal channel segment 31 leading to the dispensing opening (fig. 6) . The first vertical channel segment 28 is connected to neck 9 of container 2 by means of a very narrow opening or restriction 32, which ensures that the pressure in the interior of container 2 cannot escape through the air conduit . Received in the air conduit are controllable secondary closing means 33 for closing or leaving clear the connection between pressure side P of pump 8 and outflow channel 3 as desired. These secondary closing means 33 likewise take the form of a piston with two sealing rings 34 which is slidable in chamber 29, and operate in a manner similar to the first closing means 7 in the fluid conduit; in a closed position the two sealing rings 34 lie on either side of an inflow opening 38, while in the shown open position piston 33 is retracted to such an extent that the air A can flow past the rings to outflow opening 39 of chamber 29.

Primary closing means 7 are adapted to leave outflow channel 3 clear when air pump 8 is operating, this in order to enable dispensing of fluid F from container 2 and to prevent too high a pressure occurring therein. In similar manner the secondary closing means 33 are adapted to leave clear the connection between pressure side P of pump 8 and outflow channel 3 when pump 8 is operating. In order to synchronize the opening of the closing means and the activation of pump 8 the two piston 7, 33 and electric motor 6 are here connected to a central control member . In the shown embodiment this central control member is trigger 11, which extends inward from the side of dispensing opening 4 into dosing head 10. This trigger 11 is connected at its innermost end 35 to both mutually adjacent pistons 7, 33 (fig. 4, 5) as well as to a microswitch 36 (fig. 2) which switches electric motor 6 on and off. Trigger 11 is pressed outward by a spring 37, and in the outward extended position of trigger 11 the primary and secondary closing means 7, 33 are closed and electric motor 6 is switched off. Trigger 11 can be locked in this position by sliding the slide 12 upward behind it . When the primary and secondary closing means 7, 33 are opened and electric motor 6 is switched on, the interior of container 2 is, as stated, brought under pressure by pressing air A therein, whereby fluid F is urged out of container 2 to dispensing opening 4. A small part of the air A is simultaneously guided to dispensing opening 4 so as to be there admixed into fluid F, as indicated by the arrows in fig. 3. For optimum mixing the outflow channel 3 and the air conduit here run concentrically, in any case in the vicinity of dispensing opening 4. In the shown example outflow channel 3 is arranged concentrically around the horizontal channel segment 31 (fig. 6) . The fluid F thus flows in radially at the end of outflow channel 3 and is there admixed with the axially inflowing air A in a chamber 38 (fig. 7) . Fluid F is here atomized finely and uniformly.

Because the pressure is substantially the same in the fluid conduit and the air conduit, the mixing ratio of fluid F and air A is determined by the (fixed) ratio of the throughflow surfaces of the two conduits. From chamber 38 the fluid/air mixture leaves dosing device 10 in the form of a mist via dispensing opening 4.

According to another aspect of the present invention, the dosing device is further provided with means 39 for forming a foam which are placed in front of outflow channel 3. In the shown embodiment these foaming means 39 comprise a grid 40 received in a frame 41 with an operating lip 42. Frame 41 is connected here to a nozzle 44 of dosing device 10 by means of a film hinge 43, whereby foaming means 39 are pivotable around an axis running transversely of the direction of outflow channel 3. Foaming means 39 can thus be moved between an operative position, in which grid 40 is placed in front of dispensing opening 4 (fig. 6, 9), and a rest position in which frame 41 with grid 40 lies on the top side of nozzle 44 and leaves dispensing opening 4 clear (fig. 7, 8) . In the operative position the atomized fluid/air mixture flowing out of dispensing opening 4 under pressure must thus pass through grid 40, whereby turbulence is created and extra air is drawn in from the atmosphere. A very airy foam is thus created.

Although the invention has been elucidated above on the basis of an embodiment, it will be apparent that it is not limited thereto and can be varied in many ways. A power source other than the shown electric motor could thus be applied, and many types of pump are suitable for use here . The placing of the pump and the power source could also be other than in the neck of the container, for instance around the neck or even at the position of the bottom. In addition, the primary and secondary closing means could be embodied other than shown and described here, and the movement of the foaming means could also be achieved in a different manner, for instance by being embodied slidably. Finally, the foaming means could also be applied in other types of dosing device, for instance manually operated trigger sprayers, while still retaining the associated advantages. The scope of the invention is therefore defined solely by the following claims.

Claims

1. Device for dosed dispensing of a fluid, comprising at least one container for the fluid, which is connected to at least one outflow channel which debouches in a dispensing opening, and means for pressing the fluid out of the container to the outflow channel, characterized in that the pressing means are driven by a power source and adapted to place the interior of the container under pressure, and the device further comprises controllable primary closing means for closing or leaving clear the outflow channel as desired.

2. Dosing device as claimed in claim 1, characterized in that the pressing means are adapted to place the interior of the container under a pressure of less than 1 bar, preferably 0.1 to 0.7 bar, more preferably 0.2 to 0.6 bar, and most preferably 0.3 to 0.4 bar.

3. Dosing device as claimed in claim 1 or 2, characterized in that the pressing means comprise at least one air pump with a suction side and a pressure side, wherein the suction side of the pump is connected to the atmosphere and the pressure side to the interior of the container.

4. Dosing device as claimed in claim 3, characterized in that the air pump is a non-pulsating pump, in particular a swash plate pump or a displacement pump.

5. Dosing device as claimed in claim 3 or 4, characterized in that the pressure side of the pump is further connected to the outflow channel.

6. Dosing device as claimed in claim 5, characterized in that the connection between the pressure side of the pump and the outflow channel runs through the interior of the container.

7. Dosing device as claimed in claim 5 or 6, characterized in that the connection between the pressure side of the pump and the outflow channel comprises an air conduit which debouches close to the dispensing opening.

8. Dosing device as claimed in claim 7, characterized in that the outflow channel and the air conduit run concentrically at least close to the dispensing opening .

9. Dosing device as claimed in any of the claims 5-8, characterized by controllable secondary closing means for closing or leaving clear the connection between the pressure side of the pump and the outflow channel as desired.

10. Dosing device as claimed in any of the foregoing claims, characterized in that the primary closing means are adapted to leave clear the outflow channel when the pressing means are operative.

11. Dosing device as claimed in claim 9, characterized in that the secondary closing means are adapted to leave clear the connection between the pressure side of the pump and the outflow channel when the pressing means are operative .

12. Dosing device as claimed in claim 10 or 11, characterized by a central control member connected to the primary and/or secondary closing means and the power source of the pressing means .

13. Dosing device as claimed in any of the foregoing claims, characterized in that the power source is an electric motor powered by at least one battery.

14. Dosing device as claimed in claim 13, characterized in that the container has a neck, and the electric motor and the battery are arranged in or on the neck.

15. Dosing device as claimed in claims 3 and 13 or 14, characterized in that the electric motor and the pump are structurally integrated.

16. Dosing device as claimed in any of the foregoing claims or according to the preamble of claim 1, characterized by means placed in front of the outflow channel for the purpose of forming a foam.

17. Dosing device as claimed in claims 5 and 16, characterized in that the foaming means comprise at least one grid.

18. Dosing device as claimed in claim 16 or 17, characterized in that the foaming means are movable between an operative position, in which they are placed in front of the outflow channel, and a rest position in which they leave the outflow channel clear.

19. Dosing device as claimed in claim 18, characterized in that the foaming means are pivotable around an axis running substantially transversely of the direction of the outflow channel.

20. Foaming means, evidently intended for application in a dosing device as claimed in any of the claims 16-19.