GB2329450A

GB2329450A - Improvements in or related to pressurised dispensing apparatus

Info

Publication number: GB2329450A
Application number: GB9720137A
Authority: GB
Inventors: Richard John Warby; Graham Charles Hately; Trevor Neil Martin
Original assignee: Bespak PLC
Current assignee: Consort Medical PLC
Priority date: 1997-09-22
Filing date: 1997-09-22
Publication date: 1999-03-24
Also published as: GB9720137D0; FR2768703B1; DE29817001U1; FR2768703A1

Abstract

Dispensing apparatus are disclosed for dispensing fluid from a pressurised dispensing container (10) comprising a valve (20) and attachment means (22) for attaching in use the valve to the pressured dispensing container. The valve comprising a valve stem (23) axially slidable therethrough and extending axially there from. Actuator means (40) are disclosed engageable with a distal end of the valve stem. The actuator means comprising an outlet (42) for directing fluid dispensed from the valve via the valve stem towards a user of the apparatus, when the actuator means and valve stem assembly are depressed to actuate the valve. Wherein a guide means (30) is provided fixedly engageable with the valve and in close proximity with the actuator means to constrain the actuator means and the valve stem to move axially and without lateral loads or bending moments being imparted upon the valve stem.

Description

IMPROVEMENTS IN OR RELATING TO PRESSURISED DISPENSING APPARATUS 2329450

The present invention relates to improvements in or relating to pressurised dispensing apparatus, in particular, to means of actuating pressurised dispensing containers.

Metered dose inhalers as commonly known in the prior art comprise a pressurised dispensing container to which is attached a metering valve. The metering valve comprises amongst other components a valve stem extending axially therefrom through which, upon actuation of the metering valve, product is dispensed. A common feature of such apparatus is the provision of an actuating button which engages the distal end of the valve stem. Depression of the actuating button and hence the valve stem operates the metering valve to discharge a dose of product from the pressurised dispensing container via the valve stem and out through an outlet in the actuating button.

A problem with known dispensing apparatus of this type is that manual depression of the actuating button can impart lateral loads and bending moments on the valve stem of the metering valve causing distortion, or even breakage, of the valve stem which can render the metering valve inoperative.

It is therefore an object of the present invention to provide a means of constraining the movement of the actuating button of a dispensing apparatus to move in an axial direction only and - 2 without imparting any lateral loads or bending moments on the valve stem.

Accordingly, the present invention discloses dispensing apparatus for dispensing fluid from a pressurised dispensing container comprising a valve, attachment means for attaching in use said valve to said pressured dispensing container, said valve comprising a valve stem axially slidable therethrough and extending axially there from, actuator means engageable with a distal end of said valve stem, said actuator means comprising an outlet for directing fluid dispensed from said valve via said valve stem towards a user of the apparatus, when said actuator means and valve stem assembly are depressed to actuate said valve, wherein a guide means is provided fixedly engageable with. said valve and in axially slidable contact with said actuator means to constrain said actuator means and said valve stem to move axially and without lateral loads or bending moments being imparted upon said valve stem.

Preferably said guide means comprises a collar fixedly engaged to said valve, wherein said actuator means is mounted slidingly within said collar, an internal diameter of said guide means being fractionally greater than an external diameter of said actuator means such that said actuator means moves only axially relative to said guide means and in slidable contact therewith.

Preferably said guide means is fixedly engaged with said valve means by means of a snap arrangement.

Axial movement of the actuator means towards the - 3 valve is constrained by bottoming out of the valve stem within the metering valve and axial movement of the actuator means away from the metering valve is constrained by a radial constriction provided in said guide means against which abutment means provided on an external diameter on said actuator means abut.

Preferably said actuator means comprises an actuator button having a central bore and an outlet ending in an orifice.

Preferably said attachment means comprises a ferrule attachable to said pressurised dispensing container by crimping, said guide means being fixedly engageable with said ferrule by means of a snap arrangement.

Advantageously an overcap is provided engageable with a distal end of said guide means to conceal said actuator means, said overcap being engageable with said guide means by means of a snap arrangement.

The present invention will now be described, by way of example only, with reference to the accompanying drawings of which:

Fig 1 is an exploded perspective diagram of a dispensing apparatus according to the present invention; and Fig 2 is a cross-sectional side elevation of the dispensing apparatus of Fig 1.

With reference to Figures 1 and 2, the dispensing apparatus comprises a metering valve 20 of a conventional type connected to a pressurised dispensing container 10 by a means of a ferrule 22 which is crimped about an upper end 11 of the dispensing container 10 to form a sub-assembly.

Preferably, the ferrule 22 is manufactured from aluminium.

The metering valve 20 comprises a valve body 21 through which a valve stem 23 extends axially to protrude axially from an upper surface 24 of the metering valve 20 remote from the dispensing container 10. Preferably, the valve stem 23 is manufactured from a metallic or polymeric material.

is A cylindrical actuator button 40 comprising a central bore 41 and an orifice 42 is engageable over a distal end 25 of the valve stem 23 such that the valve stem 23 is received within the central bore 41. The central bore 41 communicates with the orifice 42. A radial protrusion 43 is provided on an external surface of the actuator button 40 at a lower surface 47. Preferably the protrusion 43 is provided by a continuous circumferential formation on the external surface of the actuator button 40. Alternatively the radial protrusion may be interrupted at intervals around the circumference by gaps. The protrusion 43 may have a square cross-sectional shape or alternatively a ramped surface 45 may be provided on the lower surface of the radial protrusion 43.

A collar 30 is provided fixedly engageable with the metering valve 20 and dispensing container 10 subassembly. The collar 30 is generally cylindrical and hollow and is preferably manufactured from a polymeric material. The internal diameter of the collar 30 at a lower end 34 (the end engaged with the metering valve 20) is fractionally greater than the external diameter of side walls 26 of the ferrule 22 such that when the collar 30 is engaged with the metering valve 20 and dispensing container 10 sub-assembly the collar 30 slides axially over the ferrule 22.

The collar 30 comprises a snap arrangement 33 near its lower end 34 which engages and is fixedly retained by a lower portion 28 of the crimped ferrule 22, as shown in Figure 2, when the collar 30 is fully engaged with the metering valve/dispensing container sub-assembly. The snap arrangement 33 comprises a ramped surface 37 which encourages the collar 30 to flex radially outwardly to accommodate the movement of the snap arrangement 33 past the ferrule 22. A substantially flat upper surface 38 on the snap arrangement 33 prevents the collar being removed from the sub- assembly once engaged therewith. More than one snap arrangement 33 may be provided on the internal surface of the collar 30 spaced circumferentially there around.

The collar 30 extends axially away from the metering valve 20 to surround the valve stem 23. The internal diameter of the collar 30 at an upper end 39 is manufactured to be fractionally greater than the external diameter of the cylindrical actuator button but less than the external diameter of the radial protrusion 43, such that the actuator button 40 may slide axially within the collar 30 in close proximity to the upper end 39 of the collar 30, once engaged therewith, along a common central axis but is constrained from moving laterally relative to the collar 30. The reduction in internal diameter of the collar 30 from the lower end 34 to the upper end 39 is provided by inwardly stepped side walls 31 andlor an annular flange 60 extending radially from the side walls 31 towards the actuator button 40.

The preferred assembly method of the dispensing apparatus, especially where the protrusion 43 has a square cross-section, comprises the following steps:

First, the metering valve 20 is attached to the pressurised dispensing container 10 by means of crimping of the ferrule 22. Then the actuator button 40 is engaged with the valve stem 23 such that the valve stem 23 is received within the central bore 41. Finally the collar 30 is slid axially over the metering valve 20 and actuator button 40 wherein the side walls 31 of the collar 30 are radially outwardly deflected by the ramped surfaces 37 until the snap arrangements 31 move past the side walls 26 of the ferrule 22 and engage with the lower portion 28, thus retaining the collar 30 in an axially fixed position relative to the metering valve 20, pressurised dispensing container 10 and actuator button 40. The actuator button 40 is moved towards the pressurised dispensing container 10 until the radial protrusion 43 on the external diameter of the actuator button 40 engages positively with the undercut formed by the annular flange 60 of the collar 30.

In this position, the actuator button 40 is free to be depressed relative to the collar 30 and dispensing container 10 in a direction towards the pressurised dispensing container 10 to depress the valve stem 23 relative to the valve body 21 of the metering valve 20 and hence actuate the valve 20.

7 However, the actuator button 40 is constrained from being slid back axially out of alignment with the collar 30 in a direction away from the pressurised dispensing container 10 by means of abutment of the radial protrusion 43 with the annular flange 60 of the collar 30.

Alternatively the apparatus, especially where the protrusion 43 has a ramped surface 45, can be assembled as follows. First, the metering valve 20 is attached to the pressurised dispensing container 10 by means of crimping of the ferrule 22. Next, the collar 30 is slid axially over the metering valve 20 wherein the side walls 31 are radially outwardly deflected by the ramped surfaces 37 until the snap arrangements 31 move past the side walls 26 of the ferrule 22 and engage with the lower portion 28, thus retaining the collar 30 in an axially fixed position relative to the metering valve 20 and pressurised dispensing container 10.

The actuator button 40 is then axially slid into the collar 30 such that the valve stem 23 is received within the central bore 41. The movement of the radial protrusion 43 of the actuator button 40 past the radial constriction of the annular flange 60/collar side walls 31 is accommodated by mutual deflection of the actuator button 40 and collar 30 side walls encouraged by the ramped surface 45 of the actuator button 40 contacting the collar 30. The actuator button 40 is manufactured from a polymeric material, or other flexible material, with a natural flexibility to allow this assembly method. Whilst sufficient axial force can be provided to engage the actuator button 40 with the collar 30 by means of pushing on an 8 upper surface 44 of the actuator button 40, insufficient axial force can be applied to the actuator button 40 by means of gripping the side wall of the actuator button 40 to disengage the actuator button 40 from the collar 30 once the two components have been assembled. In this way, accidental or deliberate removal of the actuator button 40 from the collar 30 is prevented. This is particularly advantageous in preventing the actuator button 40 becoming detached from the dispensing apparatus and possibly forming a choking hazard to the user of the apparatus.

The actuator button 40 is moved towards the pressurised dispensing container 10 until the radial protrusion 43 on the external diameter of the actuator button 40 engages positively with the undercut formed by the annular flange 60 of the collar 30. In this position, the actuator button 40 is free to be depressed relative to the collar 30 and dispensing container 10 in a direction towards the pressurised dispensing container 10 to depress the valve stem 23 relative to the valve body 21 of the metering valve 20 and hence actuate the valve 20. However, the actuator button 40 is constrained from being slid back axially out of alignment with the collar 30 in a direction away from the pressurised dispensing container 10 by means of abutment of the radial protrusion 43 with the annular flange 60 of the collar 30.

Alternatively, the actuator button 40 and collar 30 may be assembled together first as a sub-assembly before the collar 30 is attached to the valve 20.

An overcap 50 may be provided as part of the dispensing apparatus. The overcap 50 is designed to surround and conceal the actuator button 40 in situ within the collar 30 when the dispensing apparatus is not in use. This is advantageous in keeping the orifice 42 of the actuator button 40 clear of obstructions and in a good state of hygiene. The lower rim 51 of the overcap 50 is designed to fixedly engage a step formation on the upper end 39 of the collar 30. To aid retention of the overcap 50 with the collar 30 conformal circumferential ridges 71, 72 are provided on the internal and external surfaces of the overcap 50 and collar 30 respectively. Preferably, distinguishing features are provided at the separation point of the cap 50 and collar 30 to assist the user of the apparatus in removing the overcap 50 from the collar 30.

In use, the actuator button 40 is manually depressed by the user of the apparatus by means of applying pressure to the upper surface 44 of the actuator button 40. Downward movement of the actuator button 40 towards the pressurised dispensing container 10 causes the valve stem 23 to be depressed inwardly into the valve body 21 of the metering valve 20. operation of the -metering valve 20 is as with conventional metering valves leading to the discharge of product from the pressurised dispensing container 10 via the valve stem 23 and central bore 41 and out of the orifice 42 of the actuator button 40 in the form of an aerosol.

During axial movement of the actuator button 40 relative to the collar 30, the actuator button 40 is constrained to move only in an axial direction due to the close proximity between the internal diameter of - 10 the collar 30 at the upper end 39 and the external diameter of the actuator button 40. This prevents any lateral loads or bending moments being imparted upon the valve stem 23 which could cause distortion or breaking of the valve stem 23 and subsequent failure of the metering valve 20.

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Claims

CLAIMS:-

1. Dispensing apparatus for dispensing fluid from a pressurised dispensing container comprising a valve, attachment means for attaching in use said valve to said pressured dispensing container, said valve comprising a valve stem axially slidable therethrough and extending axially there from, actuator means engageable with a distal end of said valve stem, said actuator means comprising an outlet for directing fluid dispensed from said valve via said valve stem towards a user of the apparatus, when said actuator means and valve stem assembly are depressed to actuate said valve, wherein a guide means is provided fixedly engageable with said valve and in close proximity with said actuator means to constrain said actuator means and said valve stem to move axially and without lateral loads or bending moments being imparted upon said valve stem.

2. Dispensing apparatus as claimed in claim 1 wherein said guide means comprises a collar fixedly engaged to said valve, wherein said actuator means is mounted slidingly within said collar, an internal diameter of said guide means being fractionally greater than an external diameter of said actuator means such that said actuator means moves only axially relative to said guide means and in close proximity therewith.

3. Dispensing apparatus as claimed in claim 1 or claim 2 wherein said guide means is fixedly engaged with said valve means by means of a snap arrangement.

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4. Dispensing apparatus as claimed in any preceding claim wherein axial movement of the actuator means towards the valve is constrained by bottoming out of the valve stem within the metering valve and axial movement of the actuator means away from the metering valve is constrained by a radial constriction provided in said guide means against which abutment means provided on an external diameter on said actuator means abut.

1

5. Dispensing apparatus as claimed in any preceding claim wherein said actuator means comprises an actuator button having a central bore and an outlet ending in an orifice.

6. Dispensing apparatus as claimed in any preceding claim wherein said attachment means comprises a ferrule attachable to said pressurised dispensing container by crimping, said guide means being fixedly engageable with said ferrule by means of a snap arrangement.

7. Dispensing apparatus as claimed in any preceding claim wherein an overcap is provided engageable with a distal end of said guide means to conceal said actuator means, said overcap being engageable with said guide means by means of a snap arrangement.

8. Dispensing apparatus substantially as herein before described with reference to and as shown in the accompanying drawings.