GB2105693A

GB2105693A - Closures and containers

Info

Publication number: GB2105693A
Application number: GB08123566A
Authority: GB
Inventors: Eric Trevor Hopley
Original assignee: UG CLOSURES AND PLASTICS LIMIT
Current assignee: UG CLOSURES AND PLASTICS LIMIT
Priority date: 1981-07-31
Filing date: 1981-07-31
Publication date: 1983-03-30
Also published as: GB2105693B

Abstract

A screw-threaded container and closure cap have complementary stop means which prevent over-screwing of the cap onto the container. In a particular embodiment a screw- threaded container 5 has attached to it a closure cap with a screw-threaded skirt 2, and unscrewing of the cap from the container must be preceded by deforming a flexible annular band 8 attached to the cap skirt by bridges 7 so as to place flexible fins 9 formed on the band 8 clear of otherwise abutting lugs 10 formed on the container neck. Over-screwing of the cap on the container is prevented by stop means formed on the cap and the container, for example a truncated thread start 15 on the cap and a buttress 14 depending downwardly from the thread 13 on the container neck. <IMAGE>

Description

SPECIFICATION Closures and containers This invention relates to container/closure combinations. It relates especially to such combinations wherein the closure is screwed onto the container neck.

For various reasons it is often desirable that the closure, when screwed upon the container, should come to rest when the closure is in a particular rotational relationship vis-a-vis the container. For example, nowadays many containers and their respective closures are, for aesthetic reasons, noncircular in plan. They may for example be elliptical or oval in plan, or hexagonal in plan. When the closure is screwed onto the container it is therefore desirable that the lines of the closure, i.e.

elliptical or hexagonal for example, should continue into the container. Again, it is sometimes the case that the closure and container are provided with decorative or literary material.

The closure and container should therefore "match-up" when the closure is screwed onto the container. Yet again, with captive-type dispensing closures, the dispensing orifice is normally required to line up with a preferred axis on the container. It is an object of the invention to provide means enabling a closure to be associated with a container in a predetermined rotational relationship.

According to the invention a screw-threaded container and a closure cap therefor are provided with stop means preventing over-screwing of the closure cap onto the container.

The stop means may take any suitable form, for example complementary buttresses formed on both the cap skirt and the container neck.

Preferably there is just a single buttress on each component, although there may be a greater number, consideration being had of course to the fact that they should not disturb the normal screwing and unscrewing operations of the cap onto and from the container.

In a particularly preferred embodiment, the stop means on the container takes the form of a buttress extending downwardly from the lowermost tum of the thread on the neck; and the stop on the cap takes the form of an enlarged, e.g.

truncated, thread start. Thus, as the cap is screwed onto the container, the thread start on the cap comes up against the buttress on the container neck and further on-screwing of the cap is prevented. Preferabiy also means are provided for preventing unscrewing of the cap, for example until the cap skirt or an ancillary ring attached to the cap skirt, is deformed.

The present invention finds particular utility in the field of safety closures. Many types of safety or child-resistant closures are available and many more have been proposed. Typical amongst these is the type of cap, normally a two-piece cap, which requires the application of both downward pressure and unscrewing torque for its removal.

Such caps may be referred to for convenience as "press-and-turn" caps, and an example of such a cap is that described in U.S. Patent Specification No: 3.055,524. Another known form of childresistant cap is that which may be conveniently referred to as a "squeeze-and-turn" cap, and which requires for opening the squeezing of the cap skirt, to deform the skirt and thus disengage coacting reacting members on the cap skirt and container neck, and the simultaneous turning of the cap in the unscrewing direction. Examples of "squeeze-and-turn" caps are described in United Kingdom Patent Specifications Nos. J ,524,395, 1,521,201, 1,387,572, 1,434,546 and 2,011,869. It is with the "squeeze-and-turn" type of cap that the present invention has especial utility.

The "squeeze-and-turn" cap is a screwthreaded cap provided with a fin, lug or other projecting member, normally on the inside of its skirt or as an extension of the skirt, which coacts with a complementary member formed on the container to which the cap is applied. When the cap is screwed onto the container the lug etc., on the cap rides or snaps over the complementary member on the container neck. When the cap is unscrewed, the lug etc., comes up against the complementary member on the container neck to render further unscrewing impossible. Only when the cap skirt is deformed in order to remove the lug from abutting contact with the complementary member, can further unscrewing and removal of the cap from the container take place.

In order that the cap be removable by "authorised" personnel, it is necessary that instructions for removal should be printed or embossed on the top of the cap. Such instructions normally include diametrically opposed arrows indicating the "squeeze" points at which finger pressure should be applied to deform the cap skirt.

Often the arrows on the cap are required to be lined up with arrows on the container, before squeezing.

According to a particular aspect of the present invention a screw threaded container and a closure cap therefor, provided with complementary abutting means which tend to prohibit unscrewing of the closure cap from the container unless either the closure cap or the container is deformed to prevent said complementary abutting means from abutting are further provided with stop means preventing overscrewing of the closure cap onto the container.

The stop means are preferably so situated on the cap and container that they come into abutting relationship immediately after the lug or the like on the cap skirt has riddon over the complementary member on the container neck. It thus becomes impossible both to screw the cap further onto the container and to unscrew it therefrom, unless the cap skirt is deformed in the manner mentioned above.

An embodiment of the invention is illustrated in the drawings,in which Figure 1 is a part section of a cap applied to a container; Figure 2 is a plane view, partly in section, of the cap and container of Figure 1; and Figure 3 is an underneath plan view, partly in section, showing the cap fully screwed on to the container.

Referring to Figure 1 , a closure cap comprises a top 1 and depending skirt 2 which is internally screw-threaded. The cap is of the "wadless" variety, having an annular stopper portion 4 which fits tightly within the neck opening of a container 5 and a sealing ring 6 which sealingly engages the top of the container neck. Attached to the lower end of skirt 2, by four spaced bridges 7, is an annular band 8. Two diametrically-opposed inclined fins 9 are moulded integrally with the inside surface of the band 8.

The cap is screw-threadedly attached to the neck of a container 5. Provided on the container neck beneath the screw-threaded part are two diametrically-opposed lugs 10, each of which has a ramp-like surface 11 and a concave fin-engaging face 12.

The lowermost tum 13 of the screw-thread on the container neck is provided with a downwardly extending buttress 14. The start of the thread on the cap is enlarged and truncated to provide an abutment 1 5.

The cap is attached to the container by screwing it on in the normal fashion, and as the cap is screwed on the fins 9 ride up the surfaces 11 of the lugs 10 and "snap" back behind the lugs. Further on-screwing of the cap brings the abutment 1 5 into contact with the buttress 14, thus preventing on-screwing beyond this point.

Any attempt to unscrew the cap from the container brings the fins 9 into contact with the stop surfaces 12 of the lugs 10. The cap can thus be rotated a few degrees only in either direction.

If inwardly-directed radial pressure is now applied to the annular band 8 at the squeeze points designated S, the band will be deformed into elliptical or oval shape, the diameter of the band at the position of the fins 9 being increased to such an extent that the fins 9 will be moved clear of the stop surfaces 12. Continued counterclockwise rotation of the cap is then permitted, and the cap can be unscrewed in the normal manner.

Suitably the bridges 7 are positioned such that they are not substantially deformed during the deforming of band 8, in accordance with the teaching of our Patent Application No: 2,004,527A.

The advantages of the safety closure of the present invention are that the operating instructions on the top surface of the cap can be greatly simplified, i.e. there is no need to line up arrows etc.; that the closure may be applied at a reduced application torque, i.e. a torque sufficient to snap the fins over the lugs is all that is required; and that there is no residual torque left in the closure after application, which leads to a situation where there is no mechanical stress in the threads, a decided advantage when the closure and container are used in conjunction with such stress cracking agents as household bleach.

It will be appreciated that the specific embodiment described herein is a particular type of "squeeze-and-turn" cap having a deformable annular band attached to the lower edge of the cap skirt. The concept of the invention is, however, applicable to other forms of "squeeze-and-turn" caps, for example those described in the Patent Specifications above.

Claims

1. A screw-threaded container and a closure cap therefor, wherein there is provided stop means prevei * ring over-screwing of the closure cap onto the container.

2. A container and cap as claimed in claim 1 wherein the stop means comprise complementary buttresses formed on the skirt of the cap and the neck of the container.

3. A container and cap as claimed in claim 2, comprising a single buttress on the cap skirt and a single complementary buttress on the container neck.

4. A container and cap as claimed in claim 2 or 3 wherein the stop means on the container is in the form of a buttress extending downwardly from the lowermost turn of the thread on the container neck, and the stop on the cap is in the form of a truncated thread start.

5. A container and cap as claimed in any of claims 1 to 4 comprising means for preventing unscrewing of the cap until the skirt, or a portion of the skirt, has been deformed.

6. A container and cap as claimed in claim 5, wherein said means preventing unscrewing of the cap comprises at least one flexible fin on one of the cap skirt and the container neck, and at least one cooperating lug on the other of the cap skirt and the container neck.

7. A container and cap as claimed in claim 6 wherein an annular band is attached by spaced bridges to the cap skirt, said annular band having disposed interiorly thereof at least one flexible fin for engagement with a lug formed on the container neck.

8. A screw-threaded container and a closure cap therefor, provided with complementary abutting means which tend to prohibit unscrewing of the closure cap from the container unless either the closure cap or the container is deformed to prevent said complementary abutting means from abutting, and further provided with stop means preventing over-screwing of the closure cap onto the container.

9. A container and cap therefor, substantially as described with reference to the drawings.