Safety Cap

Abstract

A safety cap of resilient plastic material having a depending skirt within which is formed an annular rib having an anchor portion and a radially inwardly projecting locking lug diametrically opposed to such anchor portion, the rib and the locking portion being of substantial radial extent for positive engagement beneath the locking rib around the container neck to strongly resist removal of the cap. The remainder of the annular rib within the cap skirt is of reduced radial width to function in the manner of a snap rib on the lug side of the skirt. The skirt rib has a continuous annular upwardly presented cam surface for cooperation with the locking rib of the container neck to maintain the end wall of the cap in sealing engagement with the end of the neck. Rotation of the cap to bring the lug into registry with the gap through the locking rib of the container neck permits upward flexing of the lug side of the closure cap and free movement of the lug through the gap, the portions of the skirt rib on either circumferential side of the lug being of sufficiently reduced radial dimension to snap upwardly past the locking lug of the container and during continued removal of the cap to function as pilots for leading the opposite ends of the anchor portion of the container rib upwardly past the locking rib until the cap is removed.

Parent Case Text

This application is a divisional of Ser. No. 79,192 filed on Oct. 8, 1970, now U.S. Pat. No. 3,627,160.

Description

This invention relates to a new and improved safety closure cap which is particularly adapted for use on containers for pills and other medicines in a manner such as to prevent removal of the cap by children.

The present invention is an improvement over safety caps of the type exemplified in the U.S. Pat. to Grimm No. 3,393,816 of July 23, 1968, in which the cap is of a generally resilient plastic material, having locking means or projections extending inwardly from its skirt for locking disposition beneath the cooperating rib or bead around the neck of the container.

In such structures, it has been common to provide the cap skirt with an inwardly projecting lug diametrically opposed to an inwardly projecting arcuate rib segment, in such manner that when the cap is operatively applied to the container, the lug and rib segment are disposed just beneath and in positive abutting engagement with the lower face of the locking rib around the container neck to positively resist removal, though the cap is rotatable on the container neck to bring the lug into registry with a gap through the locking rib of the neck, whereby the side of the cap bearing such lug may be flexed and tilted by thumb pressure to move the lug upwardly through the gap and thus remove the cap.

Since neither of the cooperating ribs in such prior structures is of complete circular configuration, they have been incapable of cooperating in a manner to maintain the container cap in sealing engagement with the upper end of the bottle neck as is desirable in order to prevent entry of moisture into the container or the undue escape of volatile components from the container. Further, the containers employed with such prior closure caps included abutment means engaging the lower end of the cap skirt to limit movement of the cap unto the container neck and thereby to restrict any sealing engagement of the cap with the end of the container neck.

With these considerations in mind, the primary objects of the present invention are to provide a snap-on type safety closure cap for the container which is urged and maintained in sealing engagement with the end of the container neck at all times around the full periphery thereof, regardless of the rotary or angular orientation of the closure cap on the container.

Further objects are: To provide such a closure cap which may be readily snap-fitted onto the container in any position of angular orientation with respect to the container in the manner of a conventional snap cap; to provide such a cap in which the snap fit retention means interengage throughout the angular extent of the locking rib around the container neck and in all positions of angular orientation of the closure on the container neck; and to provide such a safety closure cap which, when rotated to proper position on the container neck, may readily be removed merely by moderate finger pressure and thus is particularly adapted for use by an arthritic or infirm person. Also, it is an object to provide such a closure cap which may be properly angularly rotated or oriented to removal position by a blind person merely through sense of touch or feel.

The foregoing objects are achieved by so forming the closure cap and its cooperating container as to permit the movement of the cap axially on to the container neck to be unrestricted except by contact between the end wall of the closure cap and the end of the container neck. Suitable cam means cooperating between the interior and exterior ribs of the cap skirt and the container neck cam the end wall of the neck firmly and in sealing relation against the end of the container neck incident to the elastic contraction of the cap skirt after it has been expanded by movement of the skirt rib past the rib of the neck. Further, the skirt rib extends for a full 360.degree. so that in all positions of rotation it is in camming engagement with the locking rib of the container neck for the full angular extent of the latter. The radial width of the inwardly projecting skirt lug and of an arcuate portion of the skirt rib diametrically opposed to such lug are sufficient to firmly engage beneath the locking rib of the container neck to positively resist removal of the cap. However, to permit removal when the plug is positioned by rotation of the cap in registry with the gap through the neck locking rib, the radial width of the neck bead on opposite circumferential sides of the lug, is sufficiently reduced as to afford merely a yielding holding engagement with the locking rib of the neck to permit upward tilting and removal of the cap.

The preferred embodiment of the invention is illustrated by way of exemplification in the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a closure cap in accordance with the invention, together with the upper portion of a container to which it is to be applied.

FIG. 2 is an enlarged bottom plan view of the closure cap.

FIG. 3 is a diametrical cross-section through the closure cap taken on the line 3--3 of FIG. 2; and

FIGS. 4, 5 and 6, respectively, are fragmentary cross-sections through the container cap taken respectively on the lines 4--4, 5--5 and 6--6 of FIG. 2.

Referring now in detail to the accompanying drawings, the numeral 10 therein designates a container body which may be formed of a conventional glass or plastic material having a neck 12 of circular cross-section which defines an access opening 14 into the container. Encircling the neck 12 in a radial plane thereof is an annular locking rib 16 of constant radial dimension having an upwardly presented and upwardly convergent cam surface 16' thereon and an abruptly downwardly directed lower annular face 16" which in the present embodiment is in substantially a radial plane for positive holding engagement with the cooperating portion of the closure cap as hereinafter described.

As is best seen in FIG. 1, the locking rib 16 is not completely annular, but is formed with a small gap 18 therethrough.

The closure cap 20 of the invention when applied to the neck 12 is rotatable thereon about the axis of the neck. The cap has a top or end wall 22 extending over the end of the neck and a depending cylindrical skirt 24 which encircles the neck. A locking lug 26 projects radially inwardly from one side of the skirt for locking reception beneath the locking rib 16 of the container neck, though rotation of the cap may so angularly orient it as to bring its lug into registry with the gap 18 through the locking rib, the lug being proportioned for free movement vertically through the gap 18 to permit removal of the cap.

For cooperation with the lug 16 in positively securing the cap on the container, the cap skirt has a radially inwardly projecting annular rib 28 integral therewith around its inner periphery in the same radial plane as the lug 26 and in spaced relation from the end wall 22, such that when the cap is operatively applied to the container, the ribs 16 and 28 cooperate to press the end wall 22 into sealing engagement with the annular upper end of the container neck. Projecting radially outwardly from the skirt, opposite the lug 26, is a thumb tab 30, to facilitate removal of the cap.

The cap will be formed of a suitable plastic or other material having sufficient elastic resiliency that its skirt 24 and internal rib 28 are elastically expansible for snap-fitting of the rib downwardly over the locking rib 16 of the container neck as the cap is pressed downwardly over the container neck during application. Thereafter, the expanded skirt and its rib 28 will resiliently contract beneath the locking rib 16. For expanding the skirt and its rib 28 during application of the container cap, the ribs 16 and 28 of the neck and closure cap have coacting cam means, exemplified by the upwardly directed and upwardly converging cam surface 16' of the neck locking rib 16, in conjunction with the inner periphery of the cap rib 28.

For urging the end wall 22 of the cap into sealing engagement with the end of the neck incident to resilient contraction of the skirt beneath the rib 16, the cooperating ribs are provided with further cam means exemplified here by the upwardly directed and upwardly diverging cam surface 28' at the upper edge of the bead or rib 28, the cam surface 28' being 360.degree. in extent in the preferred embodiment so as to coact with the outer periphery of the locking rib 16 throughout the entire angular extent of the latter, in any rotational position of the closure cap. Thus, even when the closure cap is angularly oriented into a removal position in which its lug 26 registers with the gap 18 through locking rib 16, the cam surface 28' of the cap engages the locking rib 16 for the entire angular extent of the latter, thereby greatly reducing the chances of inadvertent removal by a child who may accidentally have oriented the cap into removal position.

It will be noted by reference to FIGS. 2 and 4, 5 and 6, that the radial width of the skirt rib 28 is not constant. Rather it is an important feature of the invention that this rib varies in width at different angular locations therearound.

Thus, the skirt rib 28 includes an anchor portion 28A having its circumferential mid-section diametrically opposed to the retainer or locking lug 16. The anchor portion 28A and the retainer lug are of sufficient radial width, and thus in each instance project a sufficient distance beneath the locking rib 16 of the container neck to offer a strong positive resistance to upward displacement of the closure cap by manual pressure at any point around the circumference of the skirt. In fact, these parts may be and, in accordance with the preferred embodiment of the invention, are of sufficient radial width as to render impossible the removal of the cap by the mere exertion of finger pressure either by a child or by most adults.

Preferably, the variations in width of the rib 28 are arranged symmetrically to a diametrical line passing through the lug 26 and bisecting the arcuate anchor portion 28A, this being the line 3--3 of FIG. 1.

The anchor portion 28A extends for substantially half the circumference of the cap and at its opposite ends merges smoothly with the relatively reduced radial width releasing portions 28B--28B, the ends of which preferably are located about 90.degree. apart and symmetrically to the lug 26. Extending between and merging smoothly with these ends is a still further reduced radial width releasing portion 28C which extends continuously from the end of one portion 28D to the other. It will thus be seen that the skirt rib portions jointly define a complete annular rib 28 having an upwardly diverging camming and holding surface 28', the entire circumference of which is adapted for operative engagement with the downwardly directed face or surface 16" (except at the gap 18), for firmly securing the cap on the container with the top wall 22 of the cap urged into firm sealing engagement with the upper end of the container neck around the entire periphery of the latter. The arrangement is such as to permit this effect despite the interruption in the holding effect caused by the gap 18, because the gap is normally of insufficient angular extent to disrupt this 360.degree. sealing effect.

To facilitate the removal of the closure cap 20, the latter is provided with a radially outwardly directed thumb tab 30 which projects outwardly in radial alignment with the locking lug 26. With this tab 30 there may be associated a vertical reenforcing and stiffening web 32 serving as a pointer in cooperation with the apex of the triangle 34 or other indicia on the container neck to indicate when the lug 26 is accurately in registry with the gap 18 so that the cap is thus properly oriented for removal from the container. However, it is to be understood that such indicia 32 and 34 and the use thereof are by no means essential to successful operation of the invention, inasmuch as the arrangement of the closure cap in conjunction with the container is such as to facilitate the sensing of its arrival at removal position simply by feel. That is, when the cap is rotated to bring its lug 26 into registry with the gap 18, the fact of its disengagement from the undersurface 16" of the locking rib can be detected by feel, thus adapting the closure cap and container of the invention for use by persons with impaired vision.

In the use of the invention which is believed to be apparent from the foregoing description, the cap will normally be applied to the container with the rib 28 thereof projecting beneath and interengaged with the container rib 16, the cap 20 normally being in a position of angular orientation on the container such that the lug 26 is out of registry with the gap 18. In this position, the lug 26 as well as the diametrically opposed anchor portion 28A of the rib 28 will be in positive holding or locking abutment with the locking rib 16 of the container so that manual removal of the cap in such applied condition is very strongly resisted and for all practical purposes is impossible of achievement by a child.

In order to remove the cap, it may be rotated to its removal position indicated in FIG. 1, in which the lug 26 registers with the gap 18. Such position may be determined either by sense of touch or by means of the indicia 32 and 34. With the cap thus oriented, it is then necessary to apply but a moderate amount of upward finger pressure on the thumb tab 30, to urge the lug 26 upwardly through the gap 18.

Most of such upward movement of the lug 26 and its associated side of the container cap 20 will be permitted as the result of resilient flexing of the cap between the thumb tab 30 and the diametrically opposed ends of the anchor portion 28A which firmly resists upward displacement of its side of the cap. However, as the cap is thus flexed or tilted upwardly, the rib portion 28C first is disengaged in the manner of a snap rib by means of the surface 28' which is cammed outwardly to ride upwardly over the major diameter portion of the locking rib 16. As the tilting continues, the portion 28C guides the symmetrically disposed rib portions 28B upwardly past the locking rib 16. The portions 28B, which merge smoothly with the anchor portion 28A, in turn guide and facilitate the movement of the smoothly merging ends of the anchor rib 28A upwardly over the locking rib 16. After the ends of the rib portion 28A have thus been spread apart and moved past the locking rib 16 and as the movement continues, they exert an increasing removal force by virtue of the increasing area of engagement between the downwardly directed face or surface of the rib 28 with the upwardly diverging cam surface 16' of the locking rib. When the upwardly directed forces exceed the holding forces tending to retain the cap on the container, the cap suddenly snaps or pops off of the container in an axial direction in much the manner of a conventional snap applied cap.

In order to reapply the cap to the container, it may merely be seated on the container in any angular position of orientation and pressed axially downwardly, in which event the camming engagement of the upper cam surface 16' of the container locking rib will exert a spreading and expanding force causing the resilient skirt and its associated rib 28 and lug 26 to spread outwardly and then snap beneath the lug 16.

It is not essential that the releasing portions or segments 28B and 28C of the rib 28 be of constant width and in stepped relation, as in the preferred embodiment, as they may for instance, be of gradually diminishing or tapered width from the ends of the anchor segment 28A to the lug 26.

In the foregoing drawings and specification, there is specifically disclosed only the preferred embodiment of the invention, though it will readily be realized that various modifications may be made without departing from the invention as defined in the accompanying claims.

Claims

Having thus described my invention, I claim:

1. A closure cap for a container comprising a circular end wall for disposition over the neck of the container and a depending cylindrical skirt for telescoping reception of the container neck, a locking lug projecting radially inwardly from said skirt, and a finger tab projecting radially outwardly from said skirt in alignment with the locking lug, a radially inwardly projecting annular rib integral with said skirt around the inner periphery thereof in spaced relation to said end wall and in a common radial plan of the skirt with said locking lug, said skirt and its rib being elastically expansible for snap fitting of the rib downwardly over a cooperating rib of the container neck, said skirt rib having an upwardly presented upwardly diverging cam surface for cooperation with the container neck rib to cam the end wall of the cap downwardly into sealing engagement with the end of the container neck, said skirt rib comprising interconnected arcuate portions of varying radial width, including an anchor portion having its mid-section diametrically opposed to said retainer lug, and releasing portions extending between said retainer lug and the ends of said anchor portion, said retainer lug and the anchor portion being of substantially greater width in a radial plan of the skirt than said releasing portions.

2. The combination of claim 1 in which said anchor portions and said releasing portions are all integrally interconnected as a continuous annular rib, said lug being integral with and projecting radially inwardly from said releasing portion of the rib.

3. A closure cap as defined in claim 2, in which said skirt rib defines a continuous upwardly directed and upwardly diverging cam surface around the entire circumference.

4. A closure cap for a container comprising a circular end wall for disposition over the neck of the container and a depending cylindrical skirt for telescoping reception of the container neck, a radially inwardly projecting annular rib, integral with said skirt around the inner periphery thereof in spaced relation to said end wall, said skirt and its rib being elastically expansible for snap fitting of the rib downwardly over a cooperating rib of the container neck, said skirt rib comprising inter-connected arcuate portions of varying radial width, including an anchor portion of approximately 180.degree. in circumferential extent, and releasing portions extending from the ends of said anchor portion to locations substantially equidistant from said ends, said anchor portion being of substantially greater width in a radial plane of the skirt than said releasing portions.

5. A closure cap as defined in claim 4, including a finger tab projecting radially outwardly from said skirt at a location opposite said anchor portion and equidistant from the opposite ends thereof.

6. The combination of claim 5 in which said anchor portion and said releasing portions are integrally interconnected as a continuous annular rib.

7. A closure cap as defined in claim 6, in which said skirt rib defines a continuous upwardly directed and upwardly diverging cam surface around its entire circumference.