GB2297586A - Device for operating the outlet valve of an aerosol can - Google Patents

Abstract

A device for operating the valved outlet mechanism of an aerosol can comprises a one-piece member having a mounting portion (1) such as a split or continuous ring for embracing the can and a portion (10,11,20) which overlies the valve actuation button (5) and extends downwardly next to the face of the can (2) to provide an operating trigger (20). Inward pressure applied to the trigger (20) causes flexure of the portion (11) and depression of the button (5). A rib (6) on the inside of portion (10) fits into a groove (4) of the can to ensure accurate positioning of the device.

Description

TITLE: DEVICE The present invention relates to a device, notably to a lever mechanism for operating a liquefied propellant container.

BACKGROUND TO THE INVENTION: Many forms of such container are in widespread use for dispensing a wide range of materials. In general, they all comprise a metal cylindrical body containing the material to be dispensed under pressure using a liquefied propellant gas, for example butane, also held under the same pressure within the body. The container is closed with an end cap having a valved outlet therein which is typically secured to the body of the container by a rolled over or crimped type annular seam connection. When the user wishes to discharge some or all of the contents of the container, he depresses the hollow stem of the valved outlet and the contents are forced out of the container through the valved outlet by the gasification of the liquefied propellant due to the pressure differential between the interior and exterior of the container.The valved outlet can incorporate atomising means, eg. a spray nozzle in a button mounted on the free end of the valve stem, so that the contents are discharged as a spray or a foam. If desired, the valved outlet can incorporate a metered dose mechanism so that each actuation of the valve mechanism discharges a metered amount of the contents, notably for the administration of medicaments. For convenience, such types of container will be denoted generically hereinafter as aerosol cans.

Most aerosol cans require the user to depress the valve stem of the valved outlet to release the contents.

However, for the old or infirm, this action may present difficulties due not only to the small size of the head of the button mounted on the valve stem, which is typically a spray button having a diameter of 0.5 to 1.5 cms, but also due to the axial force which is required to overcome the action of the spring within the valve mechanism retaining the valve in the closed position. As a result, erratic operation of the valve typically occurs with the aged and infirm. This leads to consumer dissatisfaction with this type of container and can lead to erratic administration of medicaments using this type of container.

In order to aid operation of the valve mechanism it has been proposed to mount the aerosol can in a wall mounted housing incorporating a lever arm which acts upon the valve mechanism. This may reduce the effort required to operate the valve mechanism and convert the action required to operate the valve from a depression of the thumb (which is often difficult) to a pull on a lever (which is an easier action for the aged and infirm).

However, this limits the use of the device to those aerosol cans which can be used from a fixed location.

It has also been proposed to enlarge the valve cap so that it can be operated by applying the heel of a hand to it whilst the base of the can is stood upon a work surface or the like. However, the user must use the aerosol can in the vicinity of a work surface, which again limits its use.

It has also been proposed to provide a lever mechanism which can be mounted by a ring support on the body of the aerosol can, the lever arm bearing upon the top of the valve actuation button and being actuated by a trigger mechanism. However, such a mechanism requires the use of a number of interlinked components, which is complex and expensive. Furthermore, the trigger mechanism is ofet difficult for the aged and infirm to operate.

We have now devised a form of valve actuator mechanism which reduces the above problems.

SUMMARY OF THE INVENTION: Accordingly, the present invention provides a device for operating the valved outlet mechanism of an aerosol can, which device comprises: a. a mounting member adapted to be mounted upon the aerosol can b. a lever member operatively connected to said mounting member by a flex connection and extending radially of said mounting member so as to overlie the valve actuation mechanism when the mounting member is located upon the aerosol can; and c. trigger means comprising an extension of said lever member and extending axially with respect to said mounting member so as to extend adjacent a side wall of said aerosol can diametrically opposed to said flex connection and adapted to be depressed radially towards the axis of the aerosol can and thus flex said flex connection and cause the lever member to bear axially upon the valve actuation mechanism.

Typically, the aerosol can has a generally cylindrical body upon which the mounting member is mounted, having the valve mechanism located substantially centrally in a domed end wall of the can. However, the invention can be applied to other shapes of aerosol can if desired. For convenience, the invention will be described in terms of a conventional cylindrical bodied aerosol can.

The mounting member can comprise a cylindrical cup or vessel adapted to receive the body of the aerosol can, the base of the cup or vessel providing a stop to limit movement of the can within the vessel and thus position the valve mechanism of the can relative to the cup or vessel. If desired, the vessel can be formed with partially cut away side walls and base to reduce the weight of material in the member.

However, this may result in an excessively cumbersome device, and it is preferred to form the mounting member as a ring which slips onto the body of the aerosol can.

Preferably, the ring is a split ring so that it can be formed with a smaller internal diameter than the external diameter of the can upon which it is to be mounted, whereby the split ring is caused to gape and grip the external wall of the can frictionally. Typically, the split ring will extend axially over the side wall of the can for from 2 to 5 cms to provide a stable mounting for the connection to the lever member.

For convenience, the invention will be described hereinafter in terms of the use of a split ring mounting member.

Due to the frictional fit of the split ring upon the aerosol can body, the ring will tend to maintain a specific location upon the can body so that the flex connection between the ring and the lever member is in a specified relationship to the valve mechanism of the can.

If desired, the gape of the split ring can be at least partially closed by a suitable clamping mechanism to increase the frictional grip upon the can wall. Thus, the free ends of the annulus of the split ring can be provided with tensioning means, for example an over centre toggle fastening means.

However, we prefer to provide some positive engagement between the can and the ring which retains the ring at a specified axial location upon the can. Thus, the can will usually present an annular groove at the seam connecting the body of the can to the end cap. The ring can carry a continuous or dis-continuous inwardly directed annular rib which engages that groove and thus locates the ring axially upon the body of the can. Alternatively, the ring can be located upon the domed end wall of the can which carries the valve mechanism. The valve mechanism is usually attached to the end cap of the body of the can by a crimped or rolled over connection joint and the ring can have a rib which engages the annular groove usually present at this joint.

For convenience, the invention will be described hereinafter in terms of a device which has means, preferably the radially inwardly directed ribs, for positively locating the device at a predetermined position upon the aerosol can whereby the relative axial position of said flex connection to the valve mechanism can be determined so that axial displacement of said lever member about said flex connection is adapted to cause the lever member to engage the valve actuation mechanism and cause actuation of the valve mechanism.

The ring is provided with a flex connection by which the lever member is connected thereto. This connection is one which allows the lever member to move with respect to the mounting member due to the flexing of the material of construction of the connection. It is preferred to form the device of the invention from a structural plastic and to form the connection as a flexible portion integral with the structure of the device, for example as a thinner walled portion of the device. Preferably, the device is made from a polymer of such thickness as provides the spring in the split ring and also to the flex connection between the split ring to the lever member. In such a way the flex connection is provided as an inherent feature of the construction of the device and a measure of return spring is achieved in this connection.Such a form of construction readily leands itself to manufacture by moulding of a suitable plastic and provides a simple and low cost construction as compared to structures incorporating pivot connections.

For convenience, the invention will be described hereinafter in terms of a split ring which is connected to the lever member by a strip of the same material so as to provide a unitary construction incorporating a flexible self returning flexible connection between the ring and the lever member.

The lever member extends from the connection to overlie the valve actuating mechanism of the can and extend radially beyond the valve mechanism. The spring in the connection preferably retains the underside of the lever member in contact with the valve actuating mechanism, for example against the spray button head, whereby minor depression of the free end of the lever causes depression of the valve stem and thus actuation of the valve mechanism. By virtue of the location of the flex point of the lever member to one side of the valve mechanism and the free end of the lever member to the other, a mechanical advantage is obtained at the valve mechanism reducing the force required at the free end of the lever member required to depress the valve stem and actuate the valve mechanism.

The free end of the lever member is provided with a trigger member which extends downwardly along the side wall of the body of the aerosol can generally diametrically opposite to the flex connection. This downward extension is preferably not parallel to the side wall of the body but diverges at an angle away from the side wall, typically at from 5 to 150. Preferably, the lever and trigger members are substantially rigid so that radially inwardly pressure applied at or adjacent the free end of the trigger member extension of the lever member causes the lever member to pivot about the flex connection and thus bear axially upon the valve actuation mechanism.

Due to the increased effective length of the lever arm with the downward extension, the radial pressure required to actuate the valve mechanism is further reduced as compared to the force required to depress the valve stem directly. Furthermore, the force required to actuate the valve mechanism can be applied radially by gripping the can and the trigger member extension to the lever member in one hand and squeezing. Such an action can usually be achieved more readily by an aged or infirm person than the thumb depression required to operate a conventional aerosol can valve mechanism.Furthermore, since all the fingers of the user can be brought to bear upon the trigger member as opposed to the one or two fingers which are usually all that can be brought to bear against a conventional pivotted trigger mechanism, this further assists operation of the valve mechanism by the aged or infirm.

Due to the return spring action of the flex connection between the ring and the lever member, the pressure on the valve mechanism will be released once the radial pressure on the trigger member is released, thus allowing the valve mechanism to return automatically to the closed position.

However, it is desired that the device of the invention be configured and dimensioned so that the underside of the lever member remains in contact with the valve mechanism, for example the spray button head, so that the radial travel of the trigger member required to actuate the valve mechanism is minimised.

The device of the invention can incorporate other features which enhance its operation. Thus, for example, a slot or other aperture can be provided in that portion of the lever member located in register with the spray or other discharge from the outlet to the valve mechanism so that the contents of the can can be discharged without obstruction from the lever member. Many forms of valve button incorporate a sloped top to aid a blind person determining the orientation of the valve button and hence the direction in which the contents of the can will be discharged. The underside or shaping of the lever member of the device of the invention can mirror this slope so that a user can mount the device upon the can in a given orientation which registers the cut out or aperture in the lever member with the line of discharge of the contents of the can.

As indicated above, the device of the invention can be made as a unitary construction from a structural plastic, in which case it may be desired to incorporate reinforcing ribs or metal bars in the lever and trigger members so as to minimise excessive flexing of those members during us.

DESCRIPTION OF THE DRAWINGS: The invention will now be described by way of illustration with respect to a preferred embodiment thereof as shown in the accompanying drawings, in which Figure 1 is a diagrammatic perspective view of the device; and Figure 2 is a side part sectional view of the device of Figure 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT: The device of the invention comprises a split ring mounting member 1 which is a tight sliding fit upon the cylindrical body 2 of a conventional aerosol can having a closure cap secured at the upper end thereof by a rolled over seam 3 which also forms an annular groove 4 around the top shoulder of the body 2. The closure cap has a conventional valve actuating stem and spray button 5 protruding therefrom.

The split ring mounting member 1 is made from a rigid or structural plastic, notably from a moulded polyamide, polyester, polycarbonate, polystyrene, ABS or other suitable resin. Any suitable solid or closed pore expanded plastic can be used and many suitable plastics are available commercially.

Extending circumferentially within ring 1 is an annular rib 6 which engages with groove 4 to secure the ring 1 upon body 1 at a predetermined axial position and to minimise axial movement of the ring upon the body.

Extending axially from the top rim of ring 1 is the lever member which comprises an axial extension 10 which extends from ring 1 to substantially tha level of the top of the valve actuation button 5 and then extends radially across the width of the can body 2 to provide a radial portion 11 which overlies the button 5. Preferably, portion 11 is formed as an inverted shallow V shape to conform to the rearward slope of the top face of button 5. That part 12 of portion 11 lying in the discharge path of the spray nozzle in button 5 is partially cut away so as not to obstruct the path of flight of the spray from button 5.

Portion 11 is provided with a dependent trigger arm 20 which extends downwardly adjacent the face of body 2 diametrically opposed to the upward axial extension 10 from ring 1. Arm 20 diverges from the line of the side wall of body 1 by from 5 to 10 and terminates in a finger grip or hook 21.

The lever member formed by extension 10, portion 11 and arm 20 bears against the top of button 5 and flexes as radially inward pressure is applied to arm 13 to cause portion 11 to bear downwardly upon button 5 and actuate the valve mechanism of the aerosol can. If flexing occurs about the bend connection between the upright extension 10 and the generally horizontal portion 11, it will be seen that the effective length of lever acting upon the button (y) is about five times the distance (x) of the button 5 from this flex point, effectively providing a mechanical advantage of about 4 to the action of arm 20 on button 5. As a result a gentle radial squeeze by a user on arm 20 will cause the valve mechanism to be actuated.Due to the resilience in the flex point of the lever member, the lever member will return to its original configuration once the radial pressure on arm 20 is released, thus allowing the valve mechanism to shut off.

The lever member will usually flex at the point where a bend has been introduced into the lever. However, if desired, the flexing can be caused to occur at any other suitable point, for example at the junction of the upward axial extension 10 and the upper edge of ring 1, by reducing the thickness of material at this point or by reducing the lateral width of the extension or the lever member at this point. We have found that satisfactory results are usually obtained by flexing the lever arm about the bend between the axial extension 10 and the radial portion 11 and that where flexing at any other point is required this can radily be achieved by introducing the necessary chage in thickness of material or the width of the lever member during manufacture of the device by plastics moulding techniques.

The above device provides a simple and effective means by which a conventional aerosol can an be modified to make it easy for the aged and infirm to operate the valve mechanism. Since the device forms a simple add on component to the can, the can can be operated wherever an unmodified can can be used. When the contents of the can are fully discharged, the device can readily be removed from the empty can, the can discarded and the device fitted to a fresh can without the need for any special skills or tools.

The device of the invention can be used with a wide range of types of aerosol can to discharge a wide range of materials. However, a particular application of the invention is in the self-administration of medicaments to the aged or infirm. The low forces required to operate the device enable a user to achieve smooth and controlled actuation of the valve mechanism of the aerosol can without the erratic operation to which these patients were hitherto prone. Since pumping of the valve mechanism by fluctuating application of pressure to the valve is reduced, the risk of incorrect operation of a metered dose valve mechanism is reduced, enabling more consistent administration of medicament doses to be achieved.

Claims (11)

CLAIMS:

1. A device for operating the valved outlet actuation mechanism of an aerosol can, which device comprises: a. a mounting member adapted to be mounted upon the aerosol can b. a lever member operatively connected to said mounting member by a flex connection and extending radially of said mounting member so as to overlie the valve actuation mechanism when the mounting member is located upon the aerosol can; and c. trigger means comprising an extension of said lever member and extending axially with respect to said mounting member so as to extend axially adjacent to a side wall of said aerosol can diametrically opposed to said flex connection and adapted to be depressed radially towards the axis of the aerosol can and thus flex said flex connection and cause the lever member to bear axially upon the valve actuation mechanism.

2. A device as claimed in claim 1, wherein the mounting member comprises a ring member into which the body of the aerosol can is a frictional fit.

3. A device as claimed in claim 2, wherein the mounting member is a split ring which is adapted to extend axially over from 2 to 5 cms of the length of the aerosol can body.

4. A device as claimed in any one of the preceding claims, wherein locating means are provided for locating the device at a predetermined position upon the aerosol can whereby the relative axial position of said flex connection to the valve mechanism can be determined so that axial displacement of said lever member about said flex connection is adapted to cause the lever member to engage the valve actuation mechanism and cause actuation of the valve mechanism.

5. A device as claimed in claim 4, wherein the mounting member is provided with means which positively engage the aerosol can when the member is in the desired location.

6. A device as claimed in any one of the preceding claims wherein the mounting member is formed integrally with the lever and trigger members from a unitary plastic moulding.

7. A device as claimed in any one of the preceding claims, wherein the flex connection is provided by a reduction in the thickness or width of the lever member.

8. A device as claimed in any one of the preceding claims, wherein the trigger member is adapted to diverge at an angle of from 5 to 150 away from the side wall of the aerosol can.

9. A device as claimed in any one of the preceding claims, wherein the radially extending portion of the lever member has an aperture therein adapted to permit the flow of material from the outlet of the aerosol can across the plane of the radial portion.

10. A device as claimed in claim 1, substantially as hereinbefore described with respect to and as shown in the accompanying drawings.

11. An aerosol having mounted thereon a device as claimed in any one of the preceding claims.