GB2044735A - Pressurised dispenser and cap therefor - Google Patents

Abstract

A pressurised dispenser of the aerosol can type has a cap fitted over the press button which requires the use of a screw driver or other implement to remove it from the container, thereby to deter children, for example, from using the dispenser. The cap has an inner skirt (3) having a formation (5) which snaps under a fixed shoulder (15) to secure the cap in position, and an outer skirt (4) which seats on the top of the container. There is a slot (9) in the outer skirt through which the implement (17) can be inserted to engage with a bearing surface inside the cap for prising formation (5) out of engagement with shoulder (15) so as to release the cap. As shown, the bearing surface is formed jointly by bottom edges of vertical ribs (6) on the inner skirt. In an alternative form Fig. 3 (not shown), the bearing surface is provided by the top of the container, the implement being swung upwards to apply upward force on the outer skirt at the top of the slot for prising the cap off the container. <IMAGE>

Description

SPECIFICATION Improvements relating to pressurised dispensers This invention relates to pressurised dispensers of the kind commonly known as aerosol cans.

It is desirable that children should be deten-ed from operating such dispensers hecause they may use them improperly and possibly cause injury to thernselves or to others, and it is desirable to deter use by people handling the dispensers before they are sold.

In one known proposal to deter unauthorised use of a pressurised dispenser, the operating button is enclosed by a small plastics cover connected at the bottom by a frangible joint to an integral annulus anchored below the button to the fixed valve mounting of the dispenser. In order to remove'the cover and allow the button to be operated, the cover has to be twisted relative to the annulus to break the joint and so separate the cover from the annulus. Once the cover has been separated from the annulus, its deterrent effect against subsequent undesirable use of the dispenser, as by children, is entirely lost.

The present invention consists in a pressurised dispenser which comprises a container, a valve assembly mounted on the container, a press button for operating the valve and through which the pressurised contents of the container are discharged, a shoulder or undercut directed downwardly away from the button and fixed relative to the container, and a cap which fits over the button and comprises inner and outer skirts of which the inner one has an internal formation which has a snap engagement with the shoulder or undercut which normally resists detachment of the cap by hand alone, and the outer skirt has an opening through which the shank of a screw driver or analogous implement can be inserted for engagement with a bearing surface inside the cap, either on the cap itself or on the container, such that an upward force can be exerted on the cap by means of the screw driver or other implement to cause the internal formation to be prised out of engagement with the shoulder or undercut so as to release the cap from the container.

As the cap cannot be pulled off the container in the normal way and an implement is required to release it, children and others by whom the dispenser is not intended to be used are deterred from attempting to open the dispenser.

The cap can be refitted after the initial opening and the deterrent effect is retained because the aid of a screw driver or other prising implement is still required for each removal thereafter.

By suitable selection of the material of which the cap is made, the inherent resilience of the material may itself be sufficient to allow the elastic distortion of the inner skirt necessary to enable the internal formation to be snapped into and prised out of engagement with the shoulder or undercut. However, a iongitud.nal slit or dither suitable incision may be provided in the inner skirt to facilitate the distortion without making it possible for the cap to be removed without the use of a prising implement.

The valve assembly may be mounted on the container by the usual form of mounting cup rolled over at the rim to fix it to the top of the container.

The undersurface of the rolled-over rim conveniently provides the shoulder with which the internal formation has the snap engagement.

Preferably, the internal formation is an internal bead around the inside of the bottom of the inner skirt.

The bearing surface inside the cap may be provided by an abutment on the inner skirt against which the upward force can be exerted by the prising implement to cause the internal formation of the inner skirt to be prised out of engagement with the shoulder or undercut. The abutment may be formed by an external projection or projections on the inner skirt. One or more ribs extending longitudinally of the skirt may constitute the projection or projections. The abutment may take other suitable forms. It may possibly be formed by a bottom edge portion of the inner skirt.

Alternatively, the bearing surface may be provided by a part of the container or a fixed, rigid part of the valve assembly. Conveniently, it is the upper surface of a top wall of the container. The end of the prising implement may be engaged with the bearing surface which provides a fulcrum about which the implement may be swung upwardly to bear on the cap and expert the necessary upward force for releasing the internal formation from engagement with the shoulder or undercut. The implement may bear upwardly on the outer skirt at a downwardly directed edge of the opening.

The opening in the outer skirt in a preferred embodiment is a slot extending longitudinally of the outer skirt from the bottom edge of the skirt.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which, Figure 1 is an underneath perspective view of a cap, Figure 2 is a sectional view of the upper portion of a pressurised dispenser including the cap which is sectioned on a vertical plane containing the central axis of the cap, Figure 3 is a sectional side view similar to Figure 2 but showing another form of cap, and Figure 4 is a front view of the cap shown in Figure 3, part of a container and valve assembly also being indicated in chain-dotted lines.

Referring to Figures 1 and 2, a cap 1 of a pressurised dispenser embodying the present invention s a moulding of a plastics material, preferably a relatively stiff plastics material such as polystyrene. It has an imperforate crown portion 2 from which depend co-axial, cylindrical inner and outer skirts 3 and 4 respectively. The inner skirt 3 is shorter than the outer skirt 4.

Adjacent its bottom edge the inner skirt has an internal annular bead 5 of rectangular crosssection. On the external surface of the inner skirt are three closely spaced, vertically extending ribs 6 which are joined at their upper ends to the crown 2 and stop short of the bottom edge of the inner skirt The bottom edges of the ribs 6 together form a downwardly facing abutment 7.

Diametrically opposite to the ribs 6 there is a slit 8 in the inner skirt which extends for a substantial part of the height of the skirt from its bottom edge.

The outer skirt 4 has an elongated rectangular, open-ended slot 9 extending upwards from the bottom edge of the skirt to the level of the abutment 7. The width of the slot 9 corresponds to the horizontal distance between the outer side faces of the two flanking ribs of the three.

A container 10 of the pressurised dispenser is of a standard cylindrical form having a valve assembly 11 mounted on a domed top wall 12 by a standard pressed sheet metal mounting cup 13 having an outwardly roiled-over rim 14 by which it is fixed to the top wall 12. An undersurface of the rolled-over rim 14 forms a downwardly facing annular shoulder 1 5. The valve assembly 11 includes a conventional operating press-button 1 6 co-axial with and projecting above the mounting cup 13 and through which the pressurised contents of the container are discharged.

The internal diameter of the inner skirt 3 is complementary to the outer diameter of the mounting cup 13 as measured to the outer circumference of the rolled-over rim 14. The outer diameter of the outer skirt 4 corresponds to the diameter of the cylindrical container.

The cap is pushed on to the container and the bead 5 of the inner skirt snaps under the annular shoulder 1 5 to secure the cap firmly on the container, with the press button enclosed by the inner skirt and the crown of the cap. The outer skirt 4 seats on, or lies close to, the top wall 12 of the container.

The angular form of the bead prevents it from being disengaged from the shoulder to release the cap simply by pulling the cap by hand in the normal way. In order to remove the cap it is necessary to insert the blade of a screw driver 17, or analogous implement, through the slot 8 in the outer skirt, and engage its end with the abutment 7, as shown in Figure 2. Then, by applying upward force on the abutment by means of the screw driver 17, it is possible to force the inert skirt upwards and thereby prise the bead out of engagement with the shoulder 1 5. The slit 8 permits the necessary distortion of the inner skirt to enable the bead to be released from the shoulder.

The cap may be formed with an integral membrane which extends across the slot 8 and closes it. The membrane may be arranged to be readily broken or cut away so as to enable the screw driver or other prising implement to be inserted into the slot for removal of the cap. As the cap cannot be removed without first removing the membrane, the membrane provides a means of readily detecting any unauthorised initial opening of the container and so it acts as a further deterrent against tampering with the container.

Reference will now be made to Figures 3 and 4 of the accompanying drawings. As before the cap is a moulding of plastics material. The material may be relatively resilient, such as polypropylene.

Again, the cap has an imperforate crown portion 1 8 and co-axial inner and outer cylindrical skirts 1 9 and 20 respectively. The inner skirt 1 9 is the shorter of the two and has an internal annular bead 21 of rectangular cross-section adjacent its bottom edge. Also, the inner skirt has a slit 22 in it which extends for a substantial part of the height of the skirt from the bottom edge thereof.

Diametrically opposite to the slit 22 the outer skirt 20 is formed with a rectangular, open-ended slot 23 extending from the bottom edge of the skirt.

The width of the slot 23 is greater than its height which is substantially less than the height of the slot 9 in the cap of the previous embodiment. The top of the slot 23 is well below the level of the bottom edge of the inner skirt. Along the top and upper portions of the sides of the slot the outer skirt is reinforced by local thickening 24. Directly above the slot 23 the inner and outer skirts are spanned by an integral web 25 which extends from near the bottom of the inner skirt to the crown portion 18 of the cap.

The container to which the cap is applied is similar to that of the first described embodiment, as is the manner in which the cap is fitted and retained to the container, as will be readily understood from Figures 3 and 4.

The method of removing the cap from the container is different. The blade of a screw driver 26, or analogous implement, is inserted through the slot 23 but in this instance the end of the blade is engaged with the domed top wall of the container, as shown in Figure 3. Using the top wall as a fulcrum the screw driver is swung upwards to bring its blade into bearing engagement with the top edge of the slot and then to act as a lever to apply upward force on the outer skirt. The web 25 between the inner and outer skirts serves to reduce buckling of the outer skirt above the slot in consequence of the upward force applied by the screw driver, and also it ensures that the inner skirt lifts with the outer skirt with the result that the bead of the inner skirt is caused to be prised out of engagement with the shoulder of the valve assembly. As before, the slit 22 allows the inner skirt to distort sufficiently for the bead to be released from the shoulder. If the plastics material of which the cap is moulded is resilient enough for the inner skirt to distort sufficiently without it, the slit may be omitted. The local thickening 24 around the top of the slot 23 helps the outer skirt to withstand the force exerted on it by the screw driver at the slot without distortion, or substantially without distortion, and without being damaged.

Claims (14)

1. A pressurised dispenser which comprises a container, a valve assembly mounted on the container, a press button for operating the valve and through which the pressurised contents of the container are discharged, a shoulder or undercut directed downwardly away from the button and fixed relative to the container, and a cap which fits over the button and comprises inner and outer skirts of which the inner one has an internal formation which has a snap engagement with the shoulder or undercut which normally resists detachment of the cap by hand alone, and the outer skirt has an opening through which the shank of a screw driver or analogous implement can be inserted for engagement with a bearing surface inside the cap, either on the cap itself or on the container, such that an upward force can be exerted on the cap by means of a screw driver or other implement to cause the internal formation to be prised out of engagement with the shoulder or undercut so as to release the cap from the container.

2. A pressurised dispenser according to Claim 1 wherein the valve assembly is mounted on the container by a mounting cup having a rolled-over rim whereby it is fixed to the container and which has an under-surface which provides the shoulder with which the internal formation of the inner skirt has the snap engagement.

3. A pressurised dispenser according to Claim 1 or Claim 2 wherein the internal formation is an internal bead around the inner skirt.

4. A pressurised dispenser according to Claim 3 wherein the bead is of rectangular cross-section.

5. A pressurised dispenser according to any preceding claim wherein the inner skirt has a longitudinal incision in it which facilitates distortion of the inner skirt in consequence of the upward force exerted on the cap by means of the screw driver or other implement for releasing the internal formation from engagement with the shoulder or undercut.

6. A pressurised dispenser according to any preceding claim wherein the bearing surface is provided by an abutment on the inner skirt against which the upward force can be exerted by the screw driver or other implement to cause the internal formation to be released from engagement with the shoulder or undercut.

7. A pressurised dispenser according to Claim 6 wherein the abutment is formed by an external projection or projections on the inner skirt.

8. A pressurised dispenser according to Claim 7 wherein the or each projection is constituted by a rib extending longitudinally of the inner skirt and having a bottom edge which forms, or which together with the bottom edge of the or each other rib forms, the abutment.

9. A pressurised dispenser according to Claim 6 wherein the abutment is formed by a bottom edge portion of the inner skirt.

10. A pressurised dispenser according to any of Claims 1 to 5 wherein the bearing surface is provided by a part of the container with which the end of the screw driver or other implement can be engaged through the opening in the outer skirt, and which provides a fulcrum about which the implement may be swung upwardly to bear on the cap and exert the upward force for causing the internal formation to be released from engagement with the shoulder or undercut.

11. A pressurised dispenser according to Claim 10 wherein the screw driver or other implement bears on a downwardly directed edge of the opening.

12. A pressurised dispenser according to Claim 11 wherein the outer skirt is locally thickened around the upper portion of the opening.

1 3. A pressurised dispenser according to Claim 11 or Claim 12 wherein the inner and outer skirts are spanned by an integral web which ensures that the inner skirt lifts with the outer skirt when the upward force is exerted for causing the internal formation to be released from engagement with the shoulder or undercut.

14. A pressurised dispenser according to any preceding claim wherein the opening is a slot extending from the bottom edge of the outer skirt.

1 5. A prassurised dispenser according to any preceding claim wherein the cap is formed with an integral membrane which extends across the slot and closes it and which is adapted to be removed.

1 6. A pressurised dispenser substantially as described herein with reference to and as illustrated by Figures 1 and 2 of the accompanying .drawings.

1 7. A pressurised dispenser substantially as described herein with reference to and as illustrated by Figures 3 and 4 of the acco,npanying drawings.