WO2001040077A1

WO2001040077A1 - Foams producing device with flow regulation element

Info

Publication number: WO2001040077A1
Application number: PCT/EP2000/012071
Authority: WO
Inventors: Stefano Santagiuliana
Original assignee: Taplast S.P.A.
Priority date: 1999-12-02
Filing date: 2000-12-01
Publication date: 2001-06-07
Also published as: ITVI990247A1; AU2361401A; IT1307525B1

Abstract

The invention discloses a device for formation and delivery of foam made by mixing air with a liquid (2) contained in a bottle on the neck of which said device (3) is arranged, comprising: at least one suction pipe (6) for said liquid (2) connected to said device (3); mixing means of said air and said liquid; foam formation means associated to foam delivery means. Said device has at least one regulation element for passage of fluid associated with said at least one suction pipe, said regulation element (7) being provided with at least one hole (8) for the passage of said liquid from said container (1) to said device (3), said at least one element (7) causing a resistance to passage of said liquid to said suction pipe.

Description

FOAMS PRODUCING DEVICE WITH FLOW REGULATION ELEMENT

The present invention relates to a device for formation and delivery of foam and more particularly a flow regulation element for the liquid fed to mixing means of liquid and air in said device.

It is well known that there is a steady increase of the use in the market of devices connected to containers for liquids and adapted to transform the liquids into foams, which are just a suitable mixture of liquid and air and are implemented with several means, for instance with pumps having at least one chamber for mixing liquid and air, and foam forming means such as filtering elements arranged at the outlet of the mixing chamber on the delivery duct or for example devices generating foam without using pumps but only with a manual deformation of the container for the liquid. These foams are more and more used for instance in the field of cleaning furniture and domestic appliances such as ovens, tiles or hobs, or for personal care such as shampoos and shaving soap, hair or skin care foams, medical foams and the like. Just for the different nature of the products delivered in the form of foam, and to warrant a soft and substantial foaminess, the device for formation and delivery of foam, either a pump or other device, requires a very accurate design of the various foam generating members.

Some known devices provide for a pre-metering of air and liquid that is then mixed in two separate chambers, the one for air and the other for liquid, and then a subsequent joining in a mixing chamber of air and liquid in predetermined proportions that are clearly function also of the cross sections of the ducts for air and liquid inflow to the mixing chambers, of inflow velocity of both fluids, of inertia of the valve bodies and also of the physical features of the filtering elements making the foam with micro-holes of suitable size. There are other devices that are not provided with air and liquid metering chambers but provide for a direct inflow of air and liquid into a mixing and metering chamber. Also in this case the feeding ducts of both fluids must be properly sized so that a predetermined ratio between air and liquid is respected. From the foregoing it is clear that the achievement of a foam with acceptable features does not depend only upon the design of the device for formation and delivery of foam, but also on other factors such as for instance the particular physical structure of the filtering element for foam formation, and clearly also on the type of liquid that must be transformed into foam. More particularly the liquid that must be transformed should have peculiar characteristics of density and viscosity that play a very important role for the flow rate of liquid inside the liquid inflow ducts to the mixing chamber and also for the ability to mix the liquid with air. Indeed a pump that succeeds to generate a perfect foam of one product, does not warrant to be able to carry out the same acceptable effect with another type of product.

This caused up to now a rather broad tolerance on the quality of the obtained foam, in the sense that the market and the producers accepted to produce foams with different degree of consistency, in order to avoid multiplication of designs and products relative to foaming devices.

One of the remedies attempted to oppose the proliferation of designs and multiplication of different types of devices was to modify chemically the formulation of the compound to be foamed, for instance with such additives as to change density or viscosity of the liquid, however altering the nature of the liquid because the additive is clearly foamed together with the main product. Although this kind of remedy helps to decrease the different devices for formation and delivery of foam, it did not achieve and does not achieve as yet a drastic reduction of these types of devices. The object of the present invention is to overcome the above mentioned drawbacks.

More particularly the invention aims to create a device for formation and delivery of liquids in the form of foams that can be used with liquids of different density and viscosity characteristics, so as to withstand abroad range of variations of these characteristics of the liquid. In the frame of this object, another object is to modify in the same device and in a broad range, the liquid flow rate so as to change the ratio between mixed air and liquid without affecting the constructional features of the pump, even using identical pumps in which only the flow rate is varied while the pump design remains the same. The above mentioned objects are attained by a device for the formation and delivery of foam made by mixing a liquid contained in a bottle on the neck of which said device is arranged and comprising: at least a suction pipe of said liquid connected to said device; means for mixing said air and said liquid; foam formation means associated with foam delivery means, said device according to the wording of the main claim being characterized by having at least an element regulating the fluid flow associated with said at least one suction pipe, said regulation element being provided with at least a hole adapted to cause passage of said liquid from said container to said device, said at least one regulation element generating a resistance to passage of said liquid in said suction pipe.

According to a preferred embodiment the regulation element is an insert provided with a hole which is inserted into said suction pipe. According to another embodiment of the invention said regulation element consists of an occlusion of the suction pipe, at least one gauged hole being made in said occlusion.

Advantageously according to the hole size and the length of said regulation element, according to the invention a resistance to liquid passage is inserted, that can be measured thus changing the flow rate of the liquid as well as the ratio relative to air entering the mixing chamber. With a suitable variation of the air liquid ratio one obtains that the same device for formation and delivery of foam can optimally operate with liquids having totally different characteristics, and this of course without being obliged to change design and implementation of the device. Indeed the regulation element associated with the suction pipe can be inserted on the suction pipe before assembling said device or even before coupling the device to the container filled with liquid. In other words it is conceivable to produce foam delivery devices substantially identical and than differentiate said devices with the insert to be applied according to the liquid that should be filled in the container. The advantage of the present invention is clear because with this regulation element a considerable saving of design, implementation, stockage is achieved because the same type of pump may be used for different kinds of liquid to be foamed. Further features and characteristics of the invention will become more apparent in the following detailed description of the invention given with the aid of the drawings as an illustrative and non-limiting example and shown in the attached sheets of drawings in which:

- Fig. 1 is a sectional view of a container provided with a pump for making and delivering foam, whose suction pipe is provided with the device of the invention shown on an enlarged scale in Fig. 1a; and

- Fig. 2 shows another type of device for formation and delivery of foam, where Fig.2a shows the regulation element inserted in the suction pipe.

With reference now to Fig.1 it can be seen that container 1 is filled with a liquid 2 and on its neck the device 3 that in this example is a diaphragm pump with a chamber 4 for forming the air liquid mixture. At 5 there is the tablet transforming the air liquid mixture into foam, the liquid reaching through the suction pipe 6 the mixing chamber 4 together with air. At the bottom of suction pipe 6 a little tube 7 is inserted, for example made with the same plastic material of which the suction pipe is made, said tube having a central hole 8. Said tube 7 has a length L. Hole 8 and length L of the hole make a resistance to fluid passage and in this way cause a deceleration of the fluid flow rate to the mixing chamber 4. In this way in the mixing chamber 4 an air enriched and liquid weacker mixture will be formed. This mixture can be advantageously transformed into foam if the treated liquid has a greater viscosity or density in comparison with the liquid that was foamed with the same device 3 but without applying the insert 7.

Thus it is clear that the resistance to passage of liquid and therefore the variation of flow rate, will depend not only on the cross section of hole 8 but also the length of insert 7. In particular cases instead of only one element 7 in the suction pipe two or more elements 7 may be serially inserted so that the resistance to liquid passage will be double or multiple.

Fig.2 shows another device for formation and delivery of foam that in this case is obtained through deformation of the container 10 filled with liquid 11 instead of a pump. In this case the mixing chamber of air and liquid is indicated with reference numeral 12 and the filtering element carrying out transformation of mixture into foam is indicated with numeral 13. In the suction pipe 14 insert 15 is arranged, in this case at the upper end of the pipe but with fully similar effect as said insert is provided with a hole 16 having a length H also causing a deceleration of liquid inflow and therefore a different mixing ratio between air and liquid. Nothing prevents that insert may be provided with more than one hole. Moreover instead of being a piece introduced in the pipe, the insert may also be integral with said pipe, in other words be an occlusion of the pipe that can then be drilled with any suitable means, for instance by using laser beams to carry out gauged holes with any desired diameter. Another component that may play a role in respect of the mixing ratio between air and liquid is the roughness of surface 17 of duct 16. Also this surface roughness may play a non negligible role in slowing down liquid inflow in the mixing chamber. It can be seen that with a simple means such as application of an insert or formation of holes in an occluded suction pipe, the regulation of liquid inflow to the mixing chamber is achieved and therefore the variation of the air liquid metering ratio according to the characteristics of viscosity and density of said liquid. Consequently it is possible to make a foam with constant quality from different liquids still using the same device for formation and delivery of said foam.

Claims

1 ) A device for formation and delivery of foam made by mixing air with a liquid filled in a bottle on which neck said device is arranged comprising:

- at least a suction pipe of said liquid connected to said device; - mixing means between said air and said liquid;

- foam formation means associated with foam delivery means, characterized by having at least one regulation element of fluid passage associated with said at least one suction pipe, said regulation element being provided with at least one hole adapted to passage of said liquid from said container to said device, said at least one element causing a resistance to passage of said liquid to said suction pipe.

2) The device according to claim 1 ) characterized in that said regulation element is inserted into said suction pipe.

3) The device according to claim 1 ) characterized in that said regulation element consists of an occlusion of said suction pipe provided with at least one hole.

4) The device according to claim 1 ) characterized in that said at least one regulation element has a length proportioned to the resistance to be opposed to passage of liquid in the suction pipe. 5) The device according to claims 1 ) or 2) characterized in that said at least one element has one or more holes with a total cross sectional area inversely proportional to the resistance to passage of said liquid to said suction pipe.

6) The device according to any of the preceding claims characterized in that said at least one or more holes have a rough surface, the higher being the roughness and the greater being the resistance opposed to the passage of liquid to said suction pipe.