Safety Closure

Abstract

A safety closure for a container having an outwardly extending annular lip, said closure comprising a cap having an inwardly extending fixed lug which engages the underside of the lip and an opposite hinged lug which normally engages the underside of the lip but which can be pulled outwardly to disengage the lug permitting removal of the cap. The under surfaces of the two lugs may be tapered so that the cap can merely be pushed in place over the lip.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Safety closure for containers

2. Description of the Prior Art

Safety closures have been proposed in the past but these have suffered from the defect of having complicated mechanical parts. The closure of the present invention can be applied to any standard container having a lip and the cap portion is ordinarily a single piece of molded plastic so that it can be made at no greater expense than conventional covers or caps now in use.

SUMMARY OF THE INVENTION

It is highly desirable to provide a closure for a container which can be readily opened by an adult which requires more manual dexterity and coordination than can be achieved by a child. Drugs, pharmaceutical preparations, solvents, cleaning preparations and insecticides are some typical examples of normal domestic solutions which should be kept from children yet which must be available for use by adults. A number of safety closures have been proposed in the past but these have suffered from various defects. In some the secret to the opening of the container is so simple that a child can accidentally discover it. Others depend on the strength of the user. This is unsatisfactory since a small boy may be stronger than his mother. Another is that such structures frequently embody complicated mechanical structures having a number of parts, making them too expensive and to untrustworthy for wide spread application.

In accordance with the present invention, no modification of the container itself is necessary. Any standard container having an outwardly extending annular lip is completely satisfactory for the purposes of the invention. The cap portion of the closure can be molded as a single piece from a suitable plastic such as a polyolefin and thus, it need be no more expensive than a standard snap-on cap. In addition, the motion necessary for opening the container involves a considerable amount of coordination and it is not likely that a child might open the container accidentally.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a container and cap embodying the present invention.

FIG. 2 is a section on the line 2--2 of FIG. 1.

FIG. 3 is a section on the line 3--3 of FIG. 2.

FIG. 4 is a perspective view of a cap showing an alternate embodiment of the invention.

FIGS. 5 and 6 are each cross-sectional views of modified forms of container and cap constructions.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings by reference characters, there is shown a container generally designated 7 having a neck generally designated 9 and a cap generally designated 11. It will be understood that the container 7 forms no part of the present invention and can be in the form of any conventional container, such as the glass or plastic bottle, a metal can of any configuration or the like. The neck 9 of the container has an annular lip 13 and, in embodiments shown, this is tapered as at 15. Although such a taper constitutes a preferred form of the invention, it will be apparent that this is not essential for the operation of the invention, it only being essential that the lip have a reasonably flat bottom surface as at 17.

The cap 11 is preferably molded in one piece of a relatively soft yieldable plastic such as a polyolefin. The cap 11 has an inwardly extending fixed lug 19 having a flat upper surface 21 which mates with and engages bottom surface 17 of the lip of the container as is best seen in FIG. 2. The bottom surface of lug 19 is preferably tapered as at 23 so that when the cap is pushed on to the container, the tapered surface will cause the yieldable plastic to cam outwardly so that the cap may be merely pushed into place.

Opposite the fixed lug 19 is a hinged portion generally designated 25 and formed by a rectangular cut-out within the skirt. This portion is formed integral with the cap and at its point of connection with the balance of the top may be relieved as at 27 forming a so-called living hinge 29. Normally the hinged portion forms a continuation of the skirt as is shown in solid lines in FIG. 3. The hinged portion can be pulled outwardly as is shown in FIG. 1, but when releases, it can be returned to its former position. The hinged portion 25 includes a lug 26 having a flat upper surface 31 which engages the bottom side 17 of the lip 13 in the same manner as does the flat surface 21 of the fixed lug 19. The bottom surface of the lug 26 is preferably tapered as at 33 so that as the cap is pushed into place, the lug is cammed outwardly, allowing the lug to pass over and subsequently engage the lip of the container as in FIG. 2. The terminal end of the hinged portion is preferably dished out as at 35 to enable one to get a thumb nail under it.

When the cap 11 is in place on the container, no amount of pulling or twisting will permit the top to be removed. However, if one merely inserts a finger nail into the free end of the hinged portion 25, it can be pulled outwardly as is shown in solid lines in FIG. 1 and in dot-dash lines in FIG. 3, disengaging the lug 26 so that the cap can be readily removed from the container. This requires a precision motion and a degree of coordination not possessed by a small child so that although it is easy for an adult to open the container, it is almost impossible for a child to open the container accidentally.

In FIG. 4 another embodiment is shown wherein the cap 11A has a lug 25A. The structure is substantially like that shown in FIGS. 1 through 3 except that instead of the hinged portion 25 forming a rectangular cut-out within the skirt, the hinged portion 25 extends completely through the skirt so that there is no portion of the skirt underlying the lug.

Although not essential to the operation of the device, the cap may contain an annular groove 36 into which terminal portion 38 of the neck fits. This gives a very good sealing action in combination with the lugs described so that such containers are particularly useful for containing hygroscopic material or a liquid. In FIGS. 5 and 6 I have shown modification in which means are provided to improve the sealing of the cap on the container. Thus, the annular lip 13 on the container is provided with an upstanding annular ridge 41 fitting in a matching annular groove 42 provided on the underside of the flat bottom surfaces on each of lugs 19 and 26. The resilience of the material permits the lug on the hinged portion to be disengaged from the corresponding portion of the groove 42 with which it is engaged.

The device shown in FIG. 5, sealing of the cap is facilitated by the inclusion of a resilient disc 44 fitting within the container cap 11 and of a thickness such that it is slightly compressed by the flat annular rim of the container when the cap is in place.

A substantially similar result is obtained in the structure shown in FIG. 6 in which an annular resilient skirt 47 depends from the underside of the cap to engage the flat annular surfaces 48 of the container rim.

Claims

I claim:

1. A safety closure including a container having a neck with an outwardly extending annular lip and a cap for said container comprising in combination:

a. a cap of a resilient material having a top portion and a downwardly extending skirt,

b. said skirt extending downwardly below said lip,

c. an integral, inwardly extending fixed lug on said skirt, said lug engaging the under surface of said lip,

d. a hinged integral, inwardly extending portion opposite said fixed lug, said hinged portion having a lug also engaging the under surface of said lip,

e. said hinged portion having a living hinge connecting one end thereof to the cap whereby,

f. said lug on the hinged portion normally engages the under surface of the said lip and can be pulled outwardly to disengage the lip and permit removal of the cap.

g. the hinged lug being cut out within the skirt, with a portion of the skirt extending under the lug.