GB2136057A

GB2136057A - Aerosol spray can with flexible dip tube

Info

Publication number: GB2136057A
Application number: GB08306891A
Authority: GB
Inventors: Thomas John Smrt
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-03-12
Filing date: 1983-03-12
Publication date: 1984-09-12
Also published as: GB8306891D0

Abstract

An aerosol spray can (16) is provided with a flexible dip tube (26) so that the contents of the can may be sprayed when the can is upright, on its side, inverted, or in any position. A weight (33) on the end of the dip tube pulls the end of the dip tube toward the lowermost portion of the can as the can is moved. <IMAGE>

Description

SPECIFICATION Aerosol spray can This invention relates to aerosol spary cans.

Aerosol spray cans conventionally include a can body, a valve mounted in the top of the can, and a dip tube which is connected to the valve and extends toward the bottom of the can. The contents of the can are pressurized, and when the can is upright and the valve is opened, the pressure forces the contents of the can upwardly through the dip tube and valve and out the spray tip. However, when the can is inverted, the level of the contents is below the end of the dip tube. If the valve is opened,-the contents will not be sprayed and the pressurizing gas will escape. If the can is only partially full, the level of the contents will fall below the dip tube when the can is tilted from its upright position.

Most aerosol cans are used in a less than completely upright position. For example, when an aerosol paint can is used to paint an object or is used to paint a mark or stripe on the floor, the can is usually tilted so that the spray is directed somewhat downwardly. An aerosol hair spray can is frequently used in a tilted or even horizontal position to spray different portions of the hair. An aerosol can of oven cleaner must be tilted to spray the bottom and the lower corners of an oven. In each case, the can ceases to be functional when the level of the contents falls below the dip tube.

Some aerosol cans are not provided with a dip tube so that the can will spray its contents when it is inverted. Such cans are used, for example, in paint striping machines for spraying stripes on pavement, grass, etc. However,-such cans will not spray their contents when the can is upright.

The invention provides a flexible dip tube for an aerosol can so that the end of the dip tube isbelow the level of the contents regardless of the position of the can. A weight is mounted on the end of the dip tube to pull the end of the dip tube downwardly when the can is tilted. When the can is completely inverted, the flexible dip tube makes a 1 800 bend so that the open end of the dip tube is positioned adjacent the lowermost portion of the can.

The invention will now be explained, by way of example, in conjuction with an illustrative embodiment shown in the accompanying diagrammatic drawings, in which: Fig. 1 is a sectional view of an aerosol spray can which is provided with a flexible dip tube; Fig. 2 is a sectional view of the aerosol spray can in a tilted position; Fig. 3 is a sectional view of the spray can in a horizontal position; Fig. 4 is a view of the spray can in a position tilted below horizontal; Fig. 5 is a view of the spray can in an inverted position; Fig. 6 is an enlarged view, partially broken away, of the valve assembly and the dip tube; Fig. 7 is an end view of the dip tube taken along the line 7-7 in Fig. 6; Fig. 8 is a fragmentary sectional view taken along the line 8-8 in Fig. 7;; Fig. 9 iliustrates one method of forming the dip tube; Fig. 10 is an enlarged fragmentary view of the open end of the dip tube with another embodiment of the weight; and Fig. 11 is a fragmentary view of the open end of the dip tube with still another embodiment of the weight.

Referring to Figs. 1 to 5, the numeral 1 5 refers generally to a conventional aerosol spray device.

The aerosol device includes a cylindrical can 1 6 which has a dome-shaped top 17 and a bottom 1 8. The bottom may also be dome-shaped or concave. A top opening is provided in the domeshaped top 17, and a valve assembly 1 9 is mounted in the opening to provide a gas-tight enclosure within the can. The valve assembly is also conventional and includes a generally cupshaped outer housing 20 (Fig. 6) and an inner housing 21. The inner housing 21 is inserted into a cylindrical recess 22 in the outer housing 20 to provide a valve enclsoure. A spring-biased valve 23 within the valve enclosure allows flow of fluid through the valve assembly.In the particular embodiment of valve illustrated, a valve steam 24 extends upwardly from the valve, and a conventional nozzle or actuator is mounted on the valve stem when the aerosol device is used.

However, it will be understood that the invention can be used with any. type of aerosol valve.

A dip tube 26 is inserted over a tail piece 27 which extends outwardly from the inner housing 21 of the valve assembly. In contrast to conventional dip tubes, which are usually relatively rigid and inflexible, the dip tube 26 is freely flexible so that the configuration of the dip tube 26 can change depending upon the orientation of the spray can. The particular dip tube 26 illustrated is extruded from plastics and is provided with a bellows-like wall which is provided by a plurality of axially spaced crimps 28 and V-shaped wall portions 29 between the crimps 28. The crimps and the ridges 30 of the Vshaped wall portions function as hinges and provide flexibility to the dip tube 26. The wall of the dip tube 26 can be thinner than the walls of conventional dip tubes to further increase the flexibility.

The upper end portion 31 of the dip tube is provided with a cylindrical wall so that the dip tube can be snugly fitted onto the tail piece 27 to provide a gas-tight connection. The lower end portion 32 of the drip tube is also cylindrical to facilitate mounting a weight 33 on the bottom of the dip tube 26. The weight 33 pulls the dip tube 26 under the influence of gravity toward the lowermost portion of the can regardless of the orientation of the can. The open lower end 32 of the dip tube 26 has a pair of V-shaped notches or recesses 34 to permit the contents of the can to flow into the dip tube even when the bottom of the dip tube abuts the can.

The aerosol device is filled with liquid contents which are to be sprayed and a suitable propellant gas for forcing the contents through the dip tube 26 and the valve when the valve is opened. For example, the device can be filled with paint, hair spray, insect repellant, or any other material which is used in aerosol spray cans.

When the can is upright as in Fig. 1, the liquid contents of the can occupy the lower portion of the can and the propellant is above the liquid.

When the valve is opened, the propellant forces the liquid up the dip tube 26 and through the valve. The dip tube 26 could be advantageously slightly longer than the distance between the valve and the bottom of the can so that the bottom of the dip tube abuts the can. This ensures that the can may be completely emptied when the can is upright.

When the can is tilted from its upright position as in Fig. 2, the weight 33 pulls the open end of the dip tube 26, which is advantageously longer than the can, toward the lowermost portion of the can so that the end of the dip tube will be below the level of liquid even when the can is almost empty.

Fig. 3 illustrates the can in a horizontal position.

The weight 33 ensures that the open end of the dip tube will lie along the side of the can.

When the can is tilted beyond a horizontal position, the flexibility of the dip tube 26 and the weight of the weight 33 are such that the dip tube begins to make a U bend under the influence of gravity. Fig. 4 shows the can tilted about 450 beyond horizintal. The dip tube 26 makes a reverse bend at 36 so that the open end of the dip tube extends toward the lowermost part of the can.

In Fig. 5 the can is completely inverted. The weight 33 pulls the dip tube 26 into a complete reverse or U bend, and the open end of the dip tube is positioned adjacent the valve assembly.

The aerosol can may thus be completely emptied even when the can is inverted.

The particular weight 33 illustrated in Figs.

1-6 is annular and is inserted over the cylindrical end portion 32 of the dip tube 26. However, many other shapes and types of weights may be used. In Fig. 10, a screw 38 which is provided with a through bore 39 is screwed into the end 32 of the dip tube 26. The contents of the aerosol can flow through the bore 39, and the size of the bore may be selected to provide any desired flow restriction.

The slot (or other configuration) in the screw head permits the contents of the can to flow through the screw and into the dip tube even when the head of the screw abuts the can.

In Fig. 11, a tubular weight 42 is inserted in to the end 32 of the dip tube 26. The contents of the aerosol can flow through the inside of the tubular weight 42, and the inside diameter can be selected to provide any desired flow restriction.

Alternatively, the inside dimeter of the tubular weight 42 may be large enough to permit the weight to be inserted over the dip tube. In both alternatives, the tubular weight should be pushed far enough into/on the dip tube end 32 to leave the V-shaped notches 34 exposed, or the exposed end of the tubular weight could be notched.

One method of forming the flexible dip tube is illustrated in Fig. 9. An elongate plastics tube 45 is extruded from the nozzle 46 of a conventional extruder 47. The tube is pulled by a pair or series of driven pull rollers 48, and the periphery of each of the pull rollers is provided with teeth 49. The size of the particular rollers 48 illustrated is such that the circumference of each roller could be about three times the length of an individual dip tube. Each roller could be provided with three sets of teeth 49, and each set is separated by a space 50. The teeth 49 deform the tubular wall of the plastics tube while the plastics is still soft to form the crimps 28. The spaces 50 provide the cylindrical or uncrimped end portions 31 and 32 of the dip tube. A cut-off knife 51 reciprocates to cut the plastics tube in the middle of each of the uncrimped cylindrical portions to form the individual dip tubes, which fall into a collection bin 52.

Claims

1. An aerosol spray device comprising a can having an open top and a closed bottom, a valve mounted in the open top of the can, an elongate flexible dip tube having first and second ends, the first end of the dip tube being connected to the valve, and a weight being provided on the second end of the dip tube, whereby the flexible dip tube flexes under the influence of the weight and the second end of the dip tube is pulled downwardly by the weight toward the lowermost portion of the can.

2. A device according to Claim 1, in which the flexibility of the dip tube is such that the dip tube is folded on itself under the influence of the weight when the can is inverted so that the second end of the dip tube is adjacent the valve.

3. A device according to Claim 1 or 2, in which the second end of the dip tube is provided with a recess so that fluid may flow in to the dip tube through the second end even when the second end abuts the can.

4. A device according to Claim 1, 2 or 3, in which the dip tube is formed from plastics.

5. A device according to Claim 4, in which the dip tube is formed from extruded plastics.

6. A device according to Claim 5, in which the dip tube has a plurality of crimps which provide flexibility.

7. A device according to any one of Claims 1 to 6, in which the dip tube has a bellows-like tubular wall.

8. A device according to Claim 6 or 7, in which first and second ends of the dip tube are cylindrical.

9. A device according to any one of Claims 1 to 8, in which the weight is provided with an opening through which the contents of the can flow, the size of the opening being selected to provide desired flow restriction.

1 0. A device according to any one of Claims 1 to 4, in which the dip tube is formed from blow molded plastics.

11. A device according to any one of Claims 1 to 10, in which the length of the dip tube is longer than the distance from the valve to the bottom of the can whereby the second end of the dip tube contacts the bottom of the can when the can is upright.

12. A device according to any one of Claims 1 to 11, in which the weight is provided by a screw having a shank, a slotted head, and a bore extending through the shank and the siotted head, the shank being inserted into the second end of the dip tube.

13. An aerosol spray device constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in the accompanying drawings.

1 4. An apparatus including a device according to any one of the preceding claims.