GB1600419A - Valve for a pressurised aerosol dispensing container - Google Patents

Description

(54) VALVE FOR A PRESSURISED AEROSOL DISPENSING CONTAINER (71) We, METAL BOX LIMITED, of Queens House, Forbury Road, Reading RG1 3JH, Berkshire, a British Company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement.- This invention relates to a valve for controlling the delivery of a fluid under pressure from a container.

Aerosol containers are known which comprise a metal can closed at one end by a cone top. A mounting cup carrying a valve is fitted in the cone top. The valve comprises a housing which contains the obturating members of the valve. A dip tube leads from the housing down into the product to be dispensed. The pressure used to drive the product out through the valve is derived from the vapour pressure of a propellant. The vapour not only occupies the head space above the product but also saturates the product so that a saturated product is dispensed. In order to improve the spraying characteristics of the product delivered, the valve is provided with a vapour phase tap hole in the valve housing. The tap hole communicates with the vapour in the head space so that saturated product and supplementary vapour emerge through the valve stem.However the single exit tube in the stem leads to a spray button and permits mixing of the product and vapour before they reach the spray button.

One objective of our invention is to provide an aerosol valve adapted to deliver separately a liquid and a gaseous propellant from above the liquid to a spray button.

In a first aspect this invention provides an aerosol valve comprising in stacked relationship a propellant control gasket, a hollow spacer block, a product control gasket and a flanged housing, held together by a mounting cup so that a hollow stem may be moved axially against a return spring within the housing from a closed position in which a first bore in the stem is obturated by the propellant control gasket and a second bore in the stem is obturated by the product control gasket, to an open position in which the first and second bores are no longer obturated; a product passage is defined by the gap between the housing and stem, and a bore in the stem for delivering product simultaneously with propellant vapour; and a propellant vapour passage is defined by the space between the central portion of the mounting cap and the periphery of the housing flange and the spacer, a radial aperture through the spacer, the gap between the bore of the spacer and the stem and a second bore in the stem. The first bore is preferably concentric with the second bore.

In one embodiment the central bore of the stem is adapted to deliver product and to communicate with the inside of the housing.

In another embodiment the central bore of the stem is adapted to deliver propellant vapour and communicate with the bore of the spacer.

In both embodiments the flange of the housing may have a recess into which the product gasket fits. Also the spacer may be provided with an annular bead adapted to extend outwardly from the planar face of the spacer to sealingly engage with a gasket.

In a second aspect the invention provides an aerosol container fitted with a valve according to the first aspect Various embodiments of the invention will now be described, by way of example, and with reference to the accompanying drawings in which, Figure 1 is a diagrammatic side elevation of an aerosol can sectioned on a diameter; Fig. 2 is a detailed side elevation of a valve sectioned on a diameter while in the closed position; Fig. 2A is a perspective view of the valve stem of Fig. 2 sectioned on a diameter; Fig. 3 is a side elevation of the valve of Fig. 2 when in the open position; Fig. 4 is a side elevation of an alternative embodiment; and Fig. 5 is a sketch of an alternative preassembly for the valve of Fig. 4; In Fig. 1 the can comprises a body 1, a bottom wall 2 and a cone top 3.A valve mounting cup 4 is mounted within the cone top 3 and carries a valve 5 which is fitted with a spray button 6 and a dip tube 7.

In Fig. 2 a central portion 8 of the valve mounting cup 4 supports the members of the valve 5. The valve 5 comprises a valve stem 9, an annular propellant control gasket 10, an annular spacer block 11, an annular product control gasket 12, a return spring 13 and a housing 14. The dip tube 7 is attached to a tubular portion 16 of the housing and extends down into the product 15.

Fig. 2A shows the valve stem 9 to have a peg portion 17 adapted for entry into the spring 13, (as shown in Fig. 2). The valve stem further comprises a cylindrical portion 18 adapted to press upon the spring, a first neck portion 19, a first frusto conical portion 20, a second neck portion 21 and a second frusto conical portion 22 and a hollow cylindrical portion 23 adapted to receive an actuator button which is not shown. A first bore 24 extends axially from the prouuding free end 42 of the cylindrical portion 23 into the first neck portion 19 where it connects with a radial bore 25, best seen in Fig. 2. A second bore 26 surrounds the first bore 24 and extends axially into the second neck portion 21 where it connects with a radial bore 27.

When the stem 9 is assembled in the valve, as shown in Fig. 2, the first radial bore is closed by the product control gasket 12 and the second radial bore is closed by the propellant control gasket 10.

The propellant control gasket 10, spacer 11, product control gasket 12 and housing 14 are held in clamped engagement by the upper surface 28 and the crimped neck 29 of the central portion 8 of the mounting cup 4.

The housing 14 has a flange 30 the periphery of which is provided with channels 31 which, together with the central portion 8 of the valve cup, define passages which permit the propellant "P" to pass from the head space above the product 15, through a radial hole 32 in the annular spacer 11, to the propellant control gasket 10.

Fig. 3 shows the valve of Fig. 2 after the stem 9 has been pressed downwards to permit delivery of the product 15 and propellant P.

The first frusto conical portion 20 of the stem 9 has deflected the product control gasket 12 to permit product 15 to rise up the dip tube 7 into the housing 14 and upwards past the spring 13 and cylindrical portion 18 of the stem, to enter the stem through the radial bore 25 which connects with the first or central bore 24.

The second frusto conical portion 22, of the stem 9, has deflected the propellant control gasket 10 to permit the propellant to pass between the inside of the central portion 8 of the cup 4 and the outside of the housing 14 to pass through the channel 31 of the housing flange 30 and onwards through the radial hole 32 in the spacer 11, to enter the stem through the radial bore 27 which connects with the second bore 26.

The product 15 and the propellant P emerge from the stem as separate streams and maybe directed by the channels of a suitable actuator button to achieve satisfactory spraying. One such suitable valve button is sold by Precision Valve. Corporation under the trade name "PREVAL".

The valve of Figs. 2 and 3 is assembled by stages. First a pre-assembly is made by inserting the peg portion 17 through the propellant control gasket 10, the spacer block 11 and the product control gasket 12, so that frictional engagement of the stem and gaskets holds them together. The spring 13 is fitted on the peg portion 17 of the stem to complete a preassembly which permits transport and handling.

The pre-assembly is fitted into the mounting cup 4 so that the stem protrudes from the central portion 8. The housing 14 is then fitted within the central portion 8 to surround the spring 13 and the lower portion of the stem 9. Axial pressure is exerted upon the housing and cup to engage the housing with the spring and push the product gasket into the recess in the housing, and during such pressure the central portion 8 of the mounting cup is crimped to the shape shown in Figs. 2 and 3, so that the gaskets 10, 12 spacer 11 and flange 31 of the housing are held in clamped relationship.

It will be appreciated that, as drawn in Figs.

2 and 3 the stem, which is long and slender, may have a tendency to tilt when depressed.

In the embodiment shown in Fig. 4 fins 32, extending radially inwards from the inside of the housing 14, provide support to prevent the tilting of a modified stem 33.

The stem 33 has two identical throats 34 and tapered sections 35 so that the propellant control gasket 36 and product control gasket 37 may be identical. The delivery end 38 of the stem is of smaller diameter than that of Figs. 2 and 3 so that the gaskets may be fitted from either end of the stem.

The spacer 11 has annular beads 39 which bite into the gaskets 36, 37 to ensure gas tight seals. The flange 30 of the housing also has an annular bead 40 for the same purpose.

In order to provide a definite path for the propellant past the flange 30 of the housing, a portion 41 of the flange is relieved and leads into the channel 31. This improved channel path for the propellant may also be incorporated in the embodiments of Figs. 2 and 3 to prevent any risk of excessive crimping causing an obstruction.

Fig. 5 shows an alternative pre-assembly sectioned upon a diameter. The pre-assembly comprises a modified stem 42, a propellant control gasket 43, a spacer block 44 and a product control gasket 45. A bore 46 extends axially through the protruding portion 47 of the stem down to the propellant control gasket 43. A passage 48 surrounds the protruding portion 47 and extends to the product control gasket 45. In the embodiment of Fig. 5 the propellant therefore emerges from the centre of the stem in contrast to the arrangement depicted in Figs. 2, 3 and 4.

The mounting cup is stamped from tinplate.

The gaskets are made from the usual flexible materials and the housing and spacer and stem are injection moulded from the usual plastics materials used in the aerosol industry.

Any risk of lateral movement of the spacer 11 within the central portion 8 of the mounting cup, may be prevented by providing the spacer with fins which hold the spacer centrally in the housing. Alternatively, the spacer may be made oval in shape so that its longer dimension fills the external diameter of the central portions.

Furthermore, the spacer may be provided with a recess in its upper surface to receive the propellant control gasket, the recess serving to centralise the gasket in the assembly.

WHAT WE CLAIM IS: - 1. An aerosol valve comprising in stacked relationship a propellant control gasket, a hollow spacer block, a product control gasket and a flanged housing, held together by a mounting cup so that a hollow stem may be moved axially against a return spring within the housing from a closed position in which a first bore in the stem is obturated by the propellant control gasket and a second bore in the stem is obturated by the product control gasket, to an open position in which the first and second bores are no longer obturated; a product passage is defined by the gap between the housing and stem, and a bore in the stem for delivering product simultaneously with propellant vapour; and a propellant vapour passage is defined by the space between the central portion of the mounting cap and the periphery of the housing flange and the spacer, a radial aperture through the spacer, the gap between the bore of the spacer and the stem and a second bore in the stem.

2. A valve according to claim 1 wherein the first bore is concentric with the second bore.

3. A valve according to claim 2 wherein the central bore of the stem is adapted to deliver product and to communicate with the inside of the housing.

4. A valve according to claim 2 wherein the central bore of the stem is adapted to deliver propellant vapour and communicate with the bore of the spacer.

5. An aerosol valve according to any preceding claim wherein the flange of the housing has a recess and the product gasket fits in the recess.

6. An aerosol valve according to any preceding claim wherein the spacer has an annular bead adapted to extend outwardly from the planar face of the spacer to sealingly engage with a gasket.

7. An aerosol valve according to any preceding claim when fitted with a dip tube to connect the valve with product and fitted on an aerosol container.

8. An aerosol valve substantially as herein before described with reference to Figs. 2, 2A and 3 of the accompanying drawings.

9. An aerosol valve substantially as herein before described with reference to Fig. 4 of the accompanying drawings.

10. An aerosol valve substantially as herein before described with reference to Fig. 5 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. 43. A passage 48 surrounds the protruding portion 47 and extends to the product control gasket 45. In the embodiment of Fig. 5 the propellant therefore emerges from the centre of the stem in contrast to the arrangement depicted in Figs. 2, 3 and 4. The mounting cup is stamped from tinplate. The gaskets are made from the usual flexible materials and the housing and spacer and stem are injection moulded from the usual plastics materials used in the aerosol industry. Any risk of lateral movement of the spacer 11 within the central portion 8 of the mounting cup, may be prevented by providing the spacer with fins which hold the spacer centrally in the housing. Alternatively, the spacer may be made oval in shape so that its longer dimension fills the external diameter of the central portions. Furthermore, the spacer may be provided with a recess in its upper surface to receive the propellant control gasket, the recess serving to centralise the gasket in the assembly. WHAT WE CLAIM IS: -

1. An aerosol valve comprising in stacked relationship a propellant control gasket, a hollow spacer block, a product control gasket and a flanged housing, held together by a mounting cup so that a hollow stem may be moved axially against a return spring within the housing from a closed position in which a first bore in the stem is obturated by the propellant control gasket and a second bore in the stem is obturated by the product control gasket, to an open position in which the first and second bores are no longer obturated; a product passage is defined by the gap between the housing and stem, and a bore in the stem for delivering product simultaneously with propellant vapour; and a propellant vapour passage is defined by the space between the central portion of the mounting cap and the periphery of the housing flange and the spacer, a radial aperture through the spacer, the gap between the bore of the spacer and the stem and a second bore in the stem.

2. A valve according to claim 1 wherein the first bore is concentric with the second bore.

3. A valve according to claim 2 wherein the central bore of the stem is adapted to deliver product and to communicate with the inside of the housing.

4. A valve according to claim 2 wherein the central bore of the stem is adapted to deliver propellant vapour and communicate with the bore of the spacer.

5. An aerosol valve according to any preceding claim wherein the flange of the housing has a recess and the product gasket fits in the recess.

6. An aerosol valve according to any preceding claim wherein the spacer has an annular bead adapted to extend outwardly from the planar face of the spacer to sealingly engage with a gasket.

7. An aerosol valve according to any preceding claim when fitted with a dip tube to connect the valve with product and fitted on an aerosol container.

8. An aerosol valve substantially as herein before described with reference to Figs. 2, 2A and 3 of the accompanying drawings.

9. An aerosol valve substantially as herein before described with reference to Fig. 4 of the accompanying drawings.

10. An aerosol valve substantially as herein before described with reference to Fig. 5 of the accompanying drawings.