GB2297126A - Dispensing actuator - Google Patents

Abstract

The dispensing actuator 1 actuates a valve 3 on a container 2 of pressurized fluid, e.g. an aerosol can, the contents of which is to be dispensed through the actuator. The actuator 1 includes a body 4 for fitting to the container and a member 6 which is movable relative to the body 4 to vary resistance to flow of pressurized fluid through a fluid path 22, 23, 28, 24 between an inlet 19 and an outlet 26 of the actuator 1, e.g. to block fluid flow. Preferably the member 6 is linearly slideable with respect to the body 4, the degree of overlap between respective passages 28, 23 providing a variable area flow path for the dispensed fluid.

Description

Dispensing Actuator This invention relates to a dispensing actuator for actuating a valve on a container of pressurized fluid which is to be dispensed through the actuator.

Such dispensing actuators may be used for dispensing pastes, gels, liquids (as jets or sprays), foams, and gases, for example.

Most commonly they are used on aerosol cans, in which case they may be referred to as spray heads. The actuator may have a stem which projects downwards into the valve (often referred to as a female valve) to be actuated or may have a downwardly open cavity for receiving a stem of the valve (often referred to as a male valve or stem valve). Normally the valve is actuated by depressing the dispensing actuator, but it is possible to provide a valve which is actuated by rocking or turning the actuator.

There have been proposals to provide a valve stem with an outlet which is opened to a variable extent, when the valve is depressed, depending on the rotary position of the actuator relative to the valve. However, these proposals have several drawbacks, such as the difficulty of identifying the desired rotary position of the actuator and the difficulty of locating the actuator in the desired position.

The present invention provides a dispensing actuator which permits the flow of pressurized fluid to be varied or blocked off.

In one aspect the present invention provides a dispensing actuator for actuating a valve on a container of pressurized fluid which is to be dispensed through the actuator, the dispensing actuator comprising an inlet and an outlet for the pressurized fluid, fluid path defining means for providing a fluid path communicating between the inlet and the outlet, and fluid flow resistance changing means for varying resistance to flow of pressurized fluid through the fluid path between the inlet and the outlet.

In another aspect the invention provides a dispensing actuator for actuating a valve on a container of pressurized fluid which is to be dispensed through the actuator, the dispensing actuator comprising an inlet portion having an inlet passageway and an outlet portion having an outlet passageway, the outlet portion being movable relative to the inlet portion between a maximum flow position, in which the exit of the inlet passageway and the entrance of the outlet passageway overlap to a given extent, and a minimum flow position, in which the said exit and entrance overlap to a lesser extent or do not overlap.

The dispensing actuator may provide the function of step-wise or continuous varition of the passage cross-section of the fluid path or the function of on/off opening/blocking of the fluid path or a combination of these two functions.

The invention will be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view, partly in axial section, of a dispensing actuator on an aerosol can; Figure 2 is a front view, partly in axial section, corresponding to Figure 1; Figure 3 is a plan view of the dispensing actuator; Figure 4 is a diagram showing overlapping passageways in an alternative embodiment of the dispensing actuator; and Figures 5 and 6 are diagrams similar to Figure 4, for two further embodiments.

The dispensing actuator 1 illustrated in Figures 1 to 3 is for use on an aerosol can 2 of conventional construction. The aerosol can 2 includes a conventional valve having a hollow stem 3 which extends axially and is depressed vertically to open the valve.

The actuator 1 includes an inlet portion or body 4 and an outlet portion or member 6 which is movably mounted on the body 4 so as to be slidable in a direction transverse to the valve axis.

The movable member 6 is slidably mounted in a transversely extending elongate recess 7 in the top of the body 4, the recess 7 having sidewalls 8 which are inclined inwardly and upwardly so as to retain similarly inclined edge surfaces 9 of the movable member 6. The member 6 is movable between an opening position (as shown), in which the front end of the member abuts against the front end-wall 11 of the recess 7, and a blocking position (not shown), in which the rear end of the member 6 abuts against the rear end-wall 12 of the recess 7.

The movable member 6 is retained in the opening position by engagement between respective protuberances 13 and 14 on the sidewall 8 and the edge surface 9 (Figure 3). Similarly the member 6 is retained in the blocking position by engagement between respective protuberances 16 and 17 on the side wall and the edge surface. The member 6 may be retained in an intermediate position or positions by similar engagement between protuberances on the body 4 and member 6. In each case the engagement can be overcome by manually pushing the member 6 along the recess 7 in the desired direction.

The inlet portion or body 4 includes a depending stub 18 whose lower end has generally cylindrical cavity 19 for receiving the valve stem 3, the lower edge 21 of the cavity being bevelled in order to facilitate assembly. A first, rising, substantially vertical, inlet passageway or duct 22 in the body 4 communicates between the cavity 19 and the recess 7. In the preferred embodiment as illustrated, the inlet passageway 22 is cylindrical and has a round (in particular circular) exit 23. The outlet portion or member 6 contains a second, outlet passageway or elbow duct 24 which communicates between the bottom and the front end of the member 6.The front end contains a hollow element 26 known as a mechanical break up insert, which is of a type well known to those skilled in the art of aerosols and need not be described in detail; it has an outlet orifice 27 which emits a fine spray of liquid droplets. The outlet passageway 24 has a round (in particular circular) entrance 28 communicating via a convergent (in particular conical) section 29 with a transversely extending narrow bore 31 which leads to the mechanical break up insert 26.

When the manually movable member 6 is in the opening position (Figures 1 to 3) the passageway 22 and 24 are in register (the entrance 28 overlapping the exit 23 to the maximum extent) and define a fluid path which has the greatest passage cross-section, which provides the least resistance to flow of pressurized fluid, and which allows the maximum flow of fluid from the inlet to the outlet of the dispensing actuator 1. As the member 6 is moved away from the opening position it can be located in an intermediate position in which the entrance ?8 and the exit 23 overlap to a smaller extent, thereby reducing the passage cross-section of the fluid path and increasing the resistance to fluid flow. In the blocking position the member 6 closes off the inlet passageway 22, the entrance 28 no longer overlapping the exit 23, so that release of the pressurized fluid is prevented whether or not the valve stem 3 is depressed.

The body 6 is connected by an integral hinge portion 32 to a cap 33 including a peripheral skirt 34 with an internal bead 36 for engaging a rim 37 of the cam 2. The combined body and cap (4/33) and the movable member 6 are each produced by injection moulding.

Figures 4 to 6 show different arrangements of the partly overlapping exit 23 and entrance 28 of the respective passageways 22 and 24. In Figure 4 the exit 23 and entrance 28 are circular and of substantially equal area, giving a gradual but relatively rapid change of resistance to fluid flow as the member 6 moves towards the opening position. In Figure 5 the right hand side of the entrance 28 is arcuate (in particular semicircular) with the same radius as the circular exit 23, while the left hand side is generally triangular, thus giving a relatively slow gradual change of resistance to fluid flow as the opening position is approached. In Figure 6 the entrance 28 has a stepped shape,thus giving a stepwise change of flow resistance. Of course, it is possible to reverse the shapes of the exit and entrance shown in Figure 5 or Figure 6.

Various other modifications may be made within the scope of the invention. For instance, the stub 18 could be made narrower and extended downwards to serve as a stem for actuating a female valve instead of the male valve illustrated. The element 26 may be omitted and the bore 31 extended to the front end of the manually movable member 6.

The body 4 may be manufactured separately from the cap 33 and need not be connected to the cap, which may be omitted. Latching means may be provided for releasably holding the manually movable member 6 in the blocking position, in order to provide an additional degree of childproofness. The body 4 may be connected to the cap 33 (at a position remote from the hinge 32) by a tamper-evident seal which is damaged or broken when the actuator is first operated.

Instead of being linearly movable, the member 6 could be mounted on the body 4 so as to be swivellable or rotatable in order to bring the passageways 22 and 24 into and out of register. Alternative fluid flow resistance changing means will readily occur to those skilled in the art of fluid flow control and valve mechanisms. In particular, a gate valve or a needle valve may be used in a fluid path between an inlet and an outlet of the dispensing actuator.

Claims (11)

Claims:

1. A dispensing actuator for actuating a valve on a container of pressurized fluid which is to be dispensed through the actuator, the dispensing actuator comprising an inlet and an outlet for the pressurized fluid, fluid path defining means for providing a fluid path communicating between the inlet and the outlet, and fluid flow resistance changing means for varying resistance to flow of pressurized fluid through the fluid path between the inlet and the outlet.

2. A dispensing actuator as claimed in claim 1, in which the actuator comprises a body and a movable member which is movably mounted on the body and which constitutes the fluid flow resistance changing means.

3. A dispensing actuator as claimed in claim 2, in which the fluid path defining means comprises a first passageway in the body and a second passageway in the movable member.

4. A dispensing actutor as claimed in claim 3, in which the member is movable towards and away from a position in which the first and second passageways are in register.

5. A dispensing actuator as claimed in claim 4, in which the movable member is linearly slidable relative to the body.

6. A dispensing actuator as claimed in any of claims 3 to 5, in which the outlet is on the movable member.

7. A dispensing actuator as claimed in any preceding claim, in which the fluid flow resistance changing means is operable to prevent fluid flow.

8. A dispensing actuator for actuating a valve on a container of pressurized fluid which is to be dispensed through the actuator, the dispensing actuator comprising an inlet portion having an inlet passageway and an outlet portion having an outlet passageway, the outlet portion being movable relative to the inlet portion between a maximum flow position, in which the exit of the inlet passageway and the entrance of the outlet passageway overlap to a given extent, and a minimum flow position, in which the said exit and entrance overlap to a lesser extent or do not overlap.

9. A dispensing actuator as claimed in claim 8, in which the outlet portion is linearly slidable relative to the inlet portion.

10. A dispensing actuator as claimed in claim 8 or 9, in which the inlet passageway is a substantially vertical duct and the outlet passageway is an elbow duct.

11. A dispensing actuator substantially as described with reference to any of the embodiments illustrated in the accompanying drawings.