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United States Patent	3,705,667
Blanie ,   et al.	December 12, 1972

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Current U.S. Class:	222/136 ; 222/145.1; 222/386.5; 222/402.1
Current International Class:	B65D 83/14 (20060101); B67d 005/52 ()
Field of Search:	222/402.1,129,136,144.5,183,402.20,97,92,145,386.5

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References Cited

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U.S. Patent Documents

3235135	February 1966	Robert et al.
3104785	September 1963	Beard, Jr.
3415425	December 1968	Knight et al.
3490651	January 1970	Abplanalp

Primary Examiner: Reeves; Robert B.
Assistant Examiner: Slattery; James M.

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Claims

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What we claim is:

1. In a proportioning device for a pressurized container holding a product which is to be dispensed in predetermined quantities with each operation of the device under the influence of a compressed fluid within the container, said device including a valve body connected with the upper end of a plunger tube, said valve body having an inlet passage communicating with the interior of the container through said plunger tube and an outlet passage communicating with the atmosphere, and valve means being positioned to normally close said outlet passage and normally open said inlet passage, the improvement comprising: a proportioning chamber made of a flexible material arranged at least partially along the length of the plunger tube to enclose the latter, the interior of the chamber normally being in communication with the interior of the pressurized container through the inlet passage and the plunger tube and communicating with the atmosphere through the outlet passage, said chamber being formed by two dihedrons which are symmetrical in relation to the plunger tube and which extend outwardly from the side edges of two semi-cylinders which are symmetrical with and normally spaced from the plunger tube, the upper and lower ends of the chamber being terminated by portions having generally trapezoidal configuration, operation of the valve means to a position closing the inlet passage and opening the outlet passage resulting in the contraction of the proportioning chamber and the discharge of the product within the chamber through the outlet passage.

2. A proportioning device according to claim 1 in which the inner walls of the half-cylinders have substantially the same radius as the outer wall of the plunger tube, said inner walls tightly enclosing the plunger tube, and the dihedrons being completely deflated leaving substantially no empty space in the chamber when the device is operated.

3. A proportioning device according to claim 1 in which the proportioning chamber includes a tubular housing extending upwardly from the upper end of the upper trapezoidal portion and the valve body and the valve means are enclosed within and supported by said tubular housing.

4. A proportioning device according to claim 3 which includes a cap for closing the pressurized container, said cap being fixedly mounted on said tubular housing, whereby the cap with the attached proportioning chamber and associated valve body, the valve means, and the plunger tube form a complete, unitary proportioning device for a container to be pressurized.

5. A valve as claimed in claim 1 characterized in that the proportioning chamber is made of plastics material.

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Description

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The present invention relates to proportioning valves for dispensers holding a product which is expelled under the influence of a compressed fluid whenever it is desired to expel a quantity of product which is approximately predetermined for each operation of the valve.

This type of pressurized container having a valve is frequently described as an "aerosol," although in most cases it does not strictly speaking involve aerosol formation in the physical sense of the word.

It is usually formed by a capsule or a bottle open at its upper end which very often forms a neck. The valve properly so called is attached to this opening or neck and is provided with a plunger tube which extends almost as far as the bottom of the container to collect the product to be expelled even when the container holds only small quantities. A proportioning chamber is associated with the valve and plunger tube. The dispensable product fills the chamber to a predetermined capacity and is then expelled, the various operations being usually controlled by the valve itself or under the influence of the propellent.

The compressed fluid, which is called "propellent fluid," can be in the form of a liquified or compressed gas depending on the physical conditions during utilization relative to the pressure-volume-temperature characteristic of the fluid or mixtures of fluids. The present invention applies particularly in the case of compressed gases, i.e., gases which in physical conditions of use do not liquify between the maximum pressure when the container is full and the minimum pressure when the container is empty.

Various kinds of proportioning valves have been proposed in prior art. Certain valves comprise proportioning chambers formed by flexible and deformable pockets made of natural or synthetic rubber which have the advantage of easily transmitting the pressures on the outside of the pocket to the product introduced into the proportioning chamber, but the incompatibility of numerous products with the rubber and the deterioration of the rubbers which wastes some of the components, and particularly additives, in the product to be dispensed or in the propellent fluid, make this type of proportioning chamber difficult to use. In addition, the successive inflating and deflating of the pocket produce modifications in volume between the beginning and end of its application which only constitutes a minor disadvantage, but also involves the risk of leakages between the interior and exterior of the chamber, which can cause the propellent fluid to be wasted by flowing into the proportioning chamber and can render the actual proportion completely inoperative. Moreover, these chambers often form irregular creases when deflated so that the proportioned product is not completely expelled from the chamber; in addition, the generally cylindrical shape of these chambers does not permit total deflation and evacuation irrespective of improvements.

Other devices in prior art have proportioning chambers formed by a cylinder provided with a piston, expulsion of the product being effected by moving the piston under the influence of the propellent fluid. Past experience has shown that such systems are too complex to be economical. Moreover, since the proportioning chamber is necessarily located in a lateral position relative to the valve and the central plunger tube, this raises difficult problems with regard to the positioning of the valve in the neck of the container.

Modifications of the latter system have been proposed, in which the cylinder is axial, but its complexity is increased particularly by the great number of joints or packing which are required for sealing and efficient operation. Moreover, the valve systems in use are sensitive and it is impossible to achieve complete security in operation and use.

Reference can also be made to valves, of which the proportioning chamber made of polyethylene assumes a generally cylindrical shape with concertinaed walls so that the chamber can be evacuated. The evacuation of the proportioned product from the chamber is easily effected by deflating the actual chamber under pressure of propellent fluid, but this device has numerous disadvantages. The chamber is necessarily located parallel to the plunger tube under the valve thereby causing difficulties in positioning particularly in the vicinity of the neck of the container; the volume in the chamber is irregular owing to the fact that the folds do not all return exactly to the same position from one operation to another. On the other hand, when the chamber is evacuated, there is in its center a substantially cylindrical space, the length of which is equal to the total width of the folds of the lateral walls, and the space remains full of the product to be dispensed which is frequently full of bubbles of propellent fluid, which only causes the inaccuracy of the charge to be increased. Furthermore, the folds in the chamber attract a great number of propellent fluid bubbles which expand at the opening of the valve and the quantity of product to be dispensed varies with the pressure in the container.

The object of the present invention is a proportioning valve device operating under the influence of a propellent fluid, which is preferably a compressed gas, and comprising a proportioning chamber which is axially disposed around the plunger tube. This chamber is made of a flexible and pressure-deformable material which has a high degree of flexibility and physical-mechanical properties which permit it to resume its original shape with maximum precision even after successive charging and evacuating operations. The shape of the chamber is such that, under the influence of the pressure of propellent fluid, deflation is complete and consequently results in total evacuation of the contents irrespective of the viscosity of the contents, which may be pastes or fluids.

The chamber comprises principally folds parallel to the plunger tube, i.e., vertical in the normal position of the container, which prevents gas bubbles from accumulating in the folds. Numerous materials are particularly suitable for producing proportioning valves according to the invention, and the important characteristics of these products must be high chemical inertia with regard to both the product to be dispensed and the propellent fluid, a long operational life, and good mechanical properties (sealability, flexibility, resilience). Numerous polymers or polycondensates are particularly suitable for this purpose, particularly polyolefines such as polyethylene or polypropylene, or polyamides.

As regards the actual valve, it can be designed of conventional materials, but its geometry must be such that no dead space is left when the proportioning chamber is evacuated. If this was not done, bubbles of propellent fluid enclosed in the product to be dispensed would expand and modify the volume of ejected product and variations in the volume of evacuated products up to 40 percent in relation to the theoretical charge have been found in certain devices according to the prior art.

To assist in the understanding of the technical features and advantages of the present invention a preferred embodiment will be described although this embodiment is non-limitative with regard to its mode of operation and the embodiments which can be produced therefrom. Reference will be made to the drawings in which:

FIG. 1 shows a longitudinal section through an assembly comprising a valve and proportioning chamber in accordance with the present invention, and

FIG. 2 shows a cross-section of a chamber and plunger tube along the line a -- a shown in FIG. 1.

The valve consists of a body 1 which supports the plunger tube 2 and is provided to accommodate the axial plunger tube on either side, and openings 3 which permit the passage of the product towards the proportioning chamber or towards the outer atmosphere. This valve member accommodates a spring 4 which can reset the valve 5 after the latter has been actuated. On the interior shoulder of the valve member, a seal 6 is held by a wedge 7, said wedge being provided with lateral holes 8 connected to the lateral hole 3 which are intended to permit the passage of the product. The valve member is finally surmounted by a joint or packing seal 9 which bears against the upper horizontal surface. The proportioning chamber 10 completely encloses the valve member which extends downwards and is reclosed on the plunger tube. It takes the form of two half-cylinders connected by two acute dihedral angles (FIG. 2) and, in vertical section, the form of two trapezia (FIG. 1).

According to FIG. 2 it appears that, when the proportioning chamber is evacuated, the dihedrons are deflated and the two half-cylinders tightly enclose the plunger tube leaving no empty space.

All these components are combined in a cap or dome 11 which is mounted on the valve member. A joint or packing 12 ensures that the container which accommodates the valve is sealed. This valve can obviously be mounted on a different cap for example a so-called "standard 1 inch" (25.4 mm) capsule.

The device operates as follows: when the valve is actuated by depressing the actuating button or push-rod 13, the valve 5 is moved downwards and its shoulder 14 is brought to bear against the seal 6 which leads to the container. While moving downwards, the valve clears a side opening 15 under the packing seal 9, thereby opening a passage between the proportioning chamber 10 and the outer atmosphere. The contents of the proportioning chamber are evacuated by passing through the openings 3, 8 and 15. This evacuation is effected under the influence of the pressure prevailing inside the container, said pressure being transferred to the product contained in the proportioning chamber through the walls of the latter which are gradually deflated until total evacuation is achieved. When the actuating button is released, the valve opening 15 passes back into the packing seal 9 which seals the passage from the outside. After disengaging from the seal 6 the shoulder of the valve 14 re-establishes the passage between the interior of the container and the proportioning chamber which is filled again ready for use.

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