EP2170721A1

EP2170721A1 - Child resistant snap on closure having improved opening features

Info

Publication number: EP2170721A1
Application number: EP08781694A
Authority: EP
Inventors: Don F. Yaeger; Richard A. Lappine; Peter M. Zielinski; Richard Francis Reifers; Robert John Mileti
Original assignee: Alcan Global Pharmaceutical Packaging Inc
Current assignee: Amcor Pharmaceutical Packaging USA Inc
Priority date: 2007-07-12
Filing date: 2008-07-11
Publication date: 2010-04-07
Also published as: WO2009009736A1; US20090020493A1; JP5121929B2; JP2010533109A; CA2692905A1; BRPI0813562A2; CN101765549A; EP2170721A4

Abstract

A child resistant package comprising a container and a snap-on closure. The container having a neck finish including an annular locking ring with at least one notch having a locking rib and notch locating indicium. The snap-on closure disposed for rotary movement on the neck finish and comprising an end wall, a resilient peripheral skirt, and a crown extending from the end wall and the skirt to form a surface with a locking lug extending radially inwardly for alignment with said notch upon rotation of the closure for removal, snap beads which are co-planar with the locking lug and extending inwardly from the skirt are longer than the notch is wide, and a finger tab comprising indicium and extending from said skirt in alignment with said locking lug, wherein said snap beads cooperate said locking ring and skirt and being interengaged with locking lug upon applying and removing the closure.

Description

CHILD RESISTANT SNAP ON CLOSURE HAVING IMPROVED OPENING

FEATURES

BACKGROUND OF THE INVENTION

[01] The invention relates to a snap-on closure adapted for use with a container available as a child-resistant package. More particularly, the improved snap-on closure of the invention has a feature which retains the integrity of the seal and snap-on fitment with the container neck finish while rendering the closure easier to open in the unlocked position.

DESCRIPTION OF RELATED ART

[02] Child resistant snap closures are widely known and are of many different varieties. In its simplest form, such as that disclosed in U.S. Pat. No. 3,627,160, the closure skirt has an inner locking lug adapted to be aligned upon closure rotation with a notch, i.e., a gap or discontinuity located in an annular locking ring on the neck finish of the container to permit closure removal. In such position, known as the "fire" position, the closure is effectively unlocked to facilitate its removal. The closure skirt likewise has a pair of circumferentially extending snap beads on its inner wall with the midpoint diametrically opposite the lug for snap locking engagement with the annular locking ring. The locking lug lies in the same plane as the locking beads to likewise snap fit beneath the locking ring when the cap is manually pressed down over the container neck.

[03] The closure skirt has an outer finger tab in alignment with the locking lug to provide a bearing surface for the operator's thumb or finger in lifting off the closure when the thumb tab and locking lug are oriented into alignment with the notch in the annular locking ring. Indicia which may be in the form of a triangle serving as a pointer is normally provided on the container neck to indicate when the locking lug is accurately in registry with the notch or gap of the annular locking ring.

[04] The closure skirt is relatively stiff and rigid although sufficiently resilient such that it flexes radially outwardly upon closure removal as co-acting cam surfaces between the snap beads and the locking ring permit the beads to ride upwardly over the major diameter portion of the locking ring in the process of disengaging the beads from the ring during closure removal in the fire position. However, the inherent hoop strength offered by the closure skirt limits its resilient expansion, thus rendering the closure difficult to remove. In particular, elderly people or those having finger dexterity or strength problems have difficulty opening such a package because of the force required, especially for the removal of small-sized snap-on closures from small-sized containers. Because of their smaller size, such closures resist flexing to a greater extent compared to larger-sized closures, hence requiring a greater removal force.

[05] Also, during closure removal, the locking lug impacts against the outer peripheral edge of the neck finish, despite the unobstructed passage of the locking lug through the notch in the annular locking ring. Because the locking lug is located at a spaced axial distance from the closure end wall and is in the same plane as the snap beads (to underlie the locking ring in the snapped-on position), the lug strikes the upper peripheral edge of the neck finish at the container opening as the closure is tilted upwardly. The lug moves in an arc as the opposite side of the closure is used as a fulcrum. This impact against the neck finish peripheral edge offers some resistance in the opening process as the lug rides upwardly over such edge. During this process the closure skirt at the finger tab elastically expands radially outwardly as limited by the inherent hoop strength of the skirt.

[06] This resistance may be overcome by those having the strength and finger dexterity to remove the cap in the fire position without much difficulty, although it may present a problem for others.

[07] Another closure design is disclosed in US Patent No. 5,292,017. This cap closure is provided with at least one break or disruption in the skirt to make it easier to open and close the closure by reducing the hoop tension.

[08] However, there remains a need for an improved, easily-opened and -closed safety closure that is child resistant.

SUMMARY OF THE INVENTION

[09] An embodiment of the present invention provides a child-resistant, snap-on closure for snap fitment with the neck finish of the container. [10] The improved snap-on closure is simple and economical to produce and operate, yet highly effective in rendering the snap closure easier to remove in the fire position while retaining its child-resistant capability.

[11] In this embodiment, the closure is a cap that snaps over the opening of a package. The neck finish of the container has an annular locking ring having a notch. The closure has a lug on the interior of the skirt and two snap beads centered diametrically opposite the locking lug on the interior of the skirt. The snap beads are located in the same plane as the locking lug. The snap beads and the lug snap-fit over the annular locking ring to secure the closure on the container. In the fire position, the lug is co- located with the notch on the annular ring to allow removal of the closure.

[12] In an embodiment, the closure also has a crown that tapers upwardly and outwardly from the skirt to make grasping the closure easier. The crown provides additional leverage than could be obtained by the prior art closures, thus reducing the lift-off force. A finger tab is located on the outside of the skirt in alignment with the locking lug to indicate the location of the lug. The notch in the annular ring is in alignment with indicium on the container. Thus, to put the closure in the fire position, the cap is rotated as required to put the finger tab into alignment with the indicium on the container, thus putting the locking lug on the closure into alignment with the notch in the annular ring.

[13] In an optional embodiment, the closure skirt may be provided with at least one accordion segment that permits the skirt to resiliently flex radially outwardly beyond the limits of its inherent hoop strength as the snap beads ride upwardly over the major diameter portion of the locking ring in the process of closure removal at the fire position. The outward expansion or flexing of the skirt as facilitated by the optional accordion segments reduces the hoop tension, thereby permitting the snap beads to more readily disengage from the annular locking ring in this optional embodiment.

[14] If desired, at least one accordion segment may be provided at one or more desired locations in the closure skirt for relaxing the hoop strength to facilitate easier disengagement of the snap beads/locking lug. Locating the optional accordion segment at or adjacent to the finger tab enables the skirt portion at the tab to flex radially outwardly as the locking lug impacts against the upper peripheral edge of the neck finish at the container opening during the process of closure removal in the fire position. When the inherent hoop strength of the closure skirt is relaxed or reduced by the provision of the at least one optional accordion segment, the locking lug can more easily ride up over the upper peripheral edge of the container neck finish to make closing easier.

[15] Because the closure skirt is resilient, the optional accordion segment in the skirt will not, when present, interfere with the ability of the closure skirt to tightly and securely snap fit with the annular locking rib on the neck finish. As will be described more fully hereinafter, more than one accordion segment in the closure skirt can be provided and different forms and shapes thereof are possible in different embodiments.

[16] In an embodiment, the cap is useful as a simple snap-on cap that is not child-resistant.

BRIEF DESCRIPTION OF THE DRAWINGS

[17] FIG. 1 is perspective view of a prior art snap closure removably mounted on the neck finish of the container and shown in the fire position.

[18] FIG. 2 is a view similar to FIG. 1 but showing the closure completely removed.

[19] FIG. 3 is a sectional view taken substantially along the line 3—3 of FIG. 1.

[20] FIG. 4 is a partial section view of a second prior art snap closure illustrating flexure of the closure during removal.

[21] FIG. 5 is a view of the second prior art disclosure illustrating discontinuities in the skirt adjacent to the tab containing the locking lug.

[22] FIG. 6 is a view of an alternative embodiment of the second prior disclosure illustrating an accordion section.

[23] FIG. 7 is a view of the cap of FIG. 6 along section 12-12.

[24] FIG. 8 is a schematic view of an embodiment of the invention, further illustrating an optional accordion section. [25] FIG. 9 is a side view of an embodiment of the closure skirt illustrating an optional accordion section, the removal tab, and the crown.

[26] FIG. 10 is a front view of the closure of FIG. 9.

[27] FIG. 11 is a bottom view of the closure of FIG. 9.

[28] FIG. 12 is a section view along A-A of FIG. 11.

[29] FIG. 13 is a detailed view of section C of FIG. 12.

[30] In the drawings, like reference characters refer to like and corresponding parts throughout the several views.

DETAILED DESCRIPTION OF THE INVENTION

[31] A prior art child resistant snap closure 20 is shown in FIGS. 1, 2, and 3 removably mounted to neck finish 21 of container 22. Both the closure and container may be of a molded high density polyethylene material or other appropriate plastic material, although the container could be formed of conventional glass or other material.

[32] The neck finish has a radially outwardly extending annular locking ring 25 with at least one notch 26 therein forming a gap, and triangular indicia 27 or the like on the neck finish in alignment with the notch.

[33] The closure has an end wall 23 and a peripheral annular skirt 24 generally of uniform cross-section. Skirt 24 of the closure has a radially inwardly extending locking lug 28 and a radially outwardly extending finger tab 29 in alignment with the locking lug. The closure skirt likewise has radially inwardly extending rib structure which may be in the form of spaced snap beads 31 having a midsection diametrically opposite locking lug 28. The snap beads are circumferentially spaced from the locking lug and lie in substantially the same radial plane therewith.

[34] The closure is snap fitted to the neck finish as locking lug 28 and snap beads 31 engage beneath locking ring 25 upon manual application of a downward force against end wall 23 with the closure in any rotative orientation relative to the container except for its orientation shown in FIGS. 1, 2, and 3, in which locking lug 28 is in alignment with notch 26. In this position, the snap beads alone engage beneath the locking rib for snap closing the closure in place.

[35] In the rotative position of FIGS. 1 , 2, and 3, with the finger tab aligned with indicium 27, the user applies an upward force against the finger tab for urging lug 28 upwardly through notch 26 incident to removal of the closure.

[36] The locking lug and/or snap beads as well as the locking ring are appropriately rounded to effect cooperative camming action as the cap is both snap fitted to the neck finish and as the closure is removed therefrom. The closure skirt resiliently expands upon flexing during the process of both snap fitting the closure in place and upon closure removal.

[37] The cap skirt has an inherent hoop strength which limits resilient expansion and flexing of the skirt in a radially outwardly direction upon snap fitting the locking lug and snap beads to the locking ring and upon releasing the snap beads from the locking ring. Further, the finger tab is close to the locking ring, providing little leverage for removal of the closure. This structural characteristic of the closure oftentimes renders it difficult to open and remove the closure by especially the elderly and/or those lacking finger dexterity and/or strength. Also, closures of a relatively small size are found difficult to open due to the added stiffness of the small sized closure.

[38] Therefore, a second prior art closure, illustrated in prior art Figs. 4-7, was developed. This closure is rendered somewhat easier to open and to remove by the provision of at least one non-frangible break or disruption in closure skirt 24 for essentially relaxing the inherent hoop strength of the closure skirt, permitting the skirt to flex from its initial position shown in solid outline in Fig. 4 outwardly to its phantom outline position shown in Fig. 4 upon releasing the snap beads from the locking ring as the beads cam outwardly to ride upwardly over the major diameter portion of the locking rib and back to its initial solid outline position as permitted by the inherent characteristics of the known plastic material employed for snap closure 20. The break or disruption may be in the form of a narrow slit or a slot 32 shown in FIG. 5 as extending from edge 33 of the skirt toward its end wall 23. More than one such slit or slot may be provided in the cap skirt to permit the closure skirt to flex radially outwardly. [39] Thus, with locking lug 28 aligned with notch 26 in readiness for closure removal, i.e., in the fire position, as shown in Figs. 1-3, finger tab 29 is manually pressed upwardly whereupon snap beads 31 disengage from locking ring 25 as the beads cam outwardly so as to ride upwardly over the major diameter portion of locking ring 25. During the process of snap bead disengagement, skirt 24 is caused to resiliently flex slightly in a radially outward direction assuming the provision of at least one slit or slot 32 in or at the vicinity of the finger tab. Figs. 6 and 7 illustrate an alternative disruption in the form of a corrugated or crimped section 35 of the cap skirt.

[40] Although this second prior art closure is somewhat easier to operate than the first prior art closure, it is still less than satisfactory. The finger tab is located in the same position relative to the locking ring and snap beads, thus providing little leverage, and thus requiring great force, for removal. Also, slots cut into the skirt, similar to those indicated in Fig. 5 (prior art), significantly reduce hoop strength and resilience of the closure, thus significantly impairing the ability of the prior art cap to return to the original shape after each time it is opened. Further, these prior art designs do not camouflage the fire position.

[41] An embodiment of the invention is an improvement over these prior art closures. This embodiment includes a crown design that adds a large, smooth surface on the outside of the closure. This surface enlarges the diameter of the closure, as the crown extends upwardly and outwardly from the top of the closure. This feature moves the lift-off movement point upwardly and laterally further away from the locking ring. Moving the fulcrum point in this way increases the leverage the user has to snap the closure off the top of the container. Increasing the leverage decreases the lift-off force required. The crown also provides a slightly larger finger tab. Also, vendors prefer a closure having the same diameter as the container and this crown design can match container diameter. Optionally, at least one accordion segment is incorporated into the skirt of the closure to further reduce the lift-off force required to open the container.

[42] In an embodiment, the indicia on both the closure and the container are made safer by elimination of sharp edges and corners to reduce any tendency to cause injury to the user while making alignment in the fire position easier in difficult conditions as, for example, in low light conditions, or when the user has limited ability to align the closure into the fire position. Thus, all corners and edges of the indicia on both the closure and the container are rounded and have no sharp edges. This design thus essentially eliminates the opportunity to cut or break the skin when handling the container or closure.

[43] Optionally, to further make the indicia safer, an embodiment of the invention forms the indicia from a composition softer and more flexible than the more rigid material from which the container and closure are made. In accordance with this embodiment, material softer than that used to form the container and the closure is overmolded onto the indicia. The skilled practitioner knows methods by which such a flexible plastic can be over-molded onto the container, closure, or both, in accordance with the guidance provided herein.

[44] Fig. 8 is a schematic view of an embodiment of the invention in relation to a container. Fig. 8 also illustrates some optional features that can be included with a closure.

[45] As shown in Fig. 8, container 22 and closure 20 include safened raised indicia (here, in the form of an arrow) 27 and 29, respectively. The indicia have no sharp edges or corners. Optionally, indicia 27 and 29 can be overmolded with material softer than the material from which the container and closure are made. Closure 20 includes crown 40 and optional accordion features 35. As shown, crown 40 can have a diameter essentially equal to the diameter of container 22.

[46] Fig. 8 also illustrates locking ring 25 disposed near the edge 36 of container 22.

Notch 26 in locking ring 25 is shown in alignment with indicium 27. Notch 26 has a shallow locking rib segment 50 continuous with the bottom (i.e. the part closer to the container) of the locking ring. This shallow locking rib segment serves to impede a child from locating the fire position. Shallow locking rib segment 50 has a height and depth significantly less than the annular locking ring. Shallow locking rib segment 50 engages the locking lug and requires the user to snap the cap off the container. Studies have shown that children often defeat the locking feature of the prior art by putting the closure in the mouth and biting it to hold the closure in one position and rotating the container while pulling it outward or bending it away from the cap. The prior art closure would pop off when the locking lug was aligned with the notch. In the embodiment of the invention having a shallow locking rib, a small force is required to overcome the resistance of the snap when in the firing position. However, the force required is sufficient to camouflage the fire position, thus making the closure significantly safer.

[47] Fig. 8 also shows optional features, such as RFID disc A, optional advertising or otherwise customizable (as, for example, with a logotype) disc B, optional dosage timing disc C, optional labeling disc with Braille indicia D, or optional programmable dosage timing reminder disc E.

[48] Fig. 9 shows a side view of the closure 20 illustrating one embodiment of the relative positions of indicium 29, one optional accordion segment 35, and crown 40 at the top of the closure.

[49] Fig. 10 is a front view of closure 20 with two optional accordion sections 35 disposed on the sides of closure 20. Indicium 29 and crown 40 also are illustrated.

[50] Fig. 11 is a bottom view of the closure 20 showing two optional accordion sections 35 centered in the skirt around indicium 29. Crown 40 also is visible. Snap beads 31 are shown diametrically opposite locking lug 28, which is aligned with indicium 29.

[51] Further, locking lug 28 is shown in alignment with indicium 29. Locking lug 28 snaps over shallow locking rib segment 50. Snap beads 31 are shown centered around a point diametrically opposite the locking lug. Optional accordion sections 35 also are shown, as is crown 40. Crown 40 extends above end 23 of the closure. The greater diameter at the top of crown 40, together with the location thereof above end 23 of the closure and a larger finger tab 29, provide a different fulcrum point that provides additional leverage that makes removal of the closure easier than either of the prior art disclosures.

[52] Snap beads 31 are longer than notch 26 is wide so that the cap cannot be removed by aligning a snap bead with the notch 26. Locking lug 28 is only slightly narrower than notch 26 so that the lug can move through notch 26 and over shallow locking rib segment 50 for removal. [53] Locating optional accordion section 35 closer to the snap beads enables the cap skirt to flex radially outwardly in the process of closure removal.

[54] The conventional child-resistant snap closure package presents another problem which oftentimes renders it difficult for some operators to remove the closure. For example, in the process of removing the prior art closure from its FIG. 1 position to that of FIG. 2, locking lug 28 (FIG. 3) impacts against upper peripheral edge 36 of the neck finish (FIG. 2) while the diametrically opposite side of the closure, as at 37 (FIG. 3), acts as a fulcrum. Lug 28 and its closure skirt cam outwardly as the lug rides upwardly over peripheral edge 36. The closure skirt flexes resiliently outwardly during this process, as limited by the inherent hoop strength of the skirt. This invention overcomes this difficulty of opening the prior art closures by addition of the crown to move the fulcrum and provide greater leverage for removal of the cap. This embodiment affords the ability to remove the cap against the force of the hoop strength of the skirt.

[55] In an optional embodiment of the invention, an accordion section is located adjacent one or both sides of finger tab or indicium 29 to further reduce the force required to open the closure. This feature permits the closure skirt at the finger tab to flex radially outwardly. As lug 28 impacts against edge 36 in the process of opening the closure, the interference between lug 28 and edge 36 is ameliorated by the accordion sections, which enable easier opening of the closure. After opening, the closure skirt at the finger tab is used to return to its normal position by the inherent characteristics of the known plastic material employed for the snap closure.

[56] Another optional embodiment of the invention includes lugs 53 illustrated in Fig. 12 and 13 on the interior surface of crown 40. As shown in Fig. 12, these lugs 53 extend circumferentially around the interior of crown 40, but are discontinuous. The discontinuities serve to provide some flexibility in the closure. The lugs are sized to engage annular locking ring 25 firmly, but to open relatively easily. In particular, there is no need to align a locking lug with the notch in the annular ring. This embodiment does not provide a child resistant closure. However, it is more easily removed than the child-resistant closure embodiment. [57] Fig. 13 shows lug 53 in detail at a spot co-incident with indicium 29. The lug snaps over the annular locking ring to close the container.

[58] From the foregoing, it can be seen that a simple yet highly effective improvement for a child resistant snap closure has been provided. The crown provides additional leverage for removal and to facilitate easier opening. Yet, in the snap-fitted condition of the closure, the snap beads and locking lug tightly and positively inter-engage with the annular locking ring on the neck finish for locking and sealing the closure in place. The shallow locking rib segment obscures the opening notch at the fire position to make it more difficult for a child to open the closure inappropriately.

[59] In particular, the safely-shaped alignment indicia reduce energy and afford easier identification of the fire position. The location and diameter of the crown makes removal easier. Also, the cap can be used as a non-safety cap by engaging lugs on the crown with the annular locking ring. Obviously, many other modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims

What is claimed is:

1. A child resistant package comprising a container having a neck finish including an annular locking ring with at least one notch having a locking rib therein and indicium indicating the location of the notch, and a snap-on closure of rigid and stiff material disposed for rotary movement on the neck finish, said snap-on closure comprising an end wall, a resilient peripheral skirt, and a crown extending upwardly and outwardly from the end wall and the skirt to form a surface that provides leverage for removal of the snap-on closure from the container with a locking lug extending radially inwardly from said skirt in alignment in a fire position with said notch upon rotation of the snap-on closure to permit removal of said snap- on closure only when in the fire position, and snap beads co-planar with the locking lug and extending inwardly from the skirt, said snap beads being longer than the notch is wide, a finger tab comprising indicium and extending radially outwardly from said skirt in alignment with said locking lug, said snap beads camming over said locking ring and resiliently expanding said skirt and the locking lug passing over the locking ring upon snap locking the snap-on closure to the neck finish and upon removal of said snap-on closure, said locking lug and said snap beads being interengaged with said locking ring upon snap locking and said locking ring becoming disengaged from said snap beads upon the removal of said snap-on closure, and said indicia being formed without sharp edges and corners.

2. The package of claim 1, wherein the indicia are formed of soft material.

3. The package of claim 1, wherein the skirt further comprises an accordion-like structure adjacent a lower peripheral edge thereof, and spaced apart from the locking lug and the snap beads to allow the skirt to flex from an initial unflexed position thereof radially outwardly and back to the initial position as said snap beads disengage from said locking ring upon the removal of said snap-on closure and as said snap beads engage said locking ring upon the snap locking of the snap-on closure to the neck finish.

4. The package of claim 3, wherein the skirt comprises two accordion-like structures located adjacent the locking lug.

5. The package of claim 1, wherein the crown has a diameter approximately equal to a diameter of the container.

6. The package of claim 1, further comprising lugs extending inwardly at a top of the crown, wherein the closure can be inverted and attached to the container securely but without child resistance.

7. A snap-on closure of rigid and stiff material disposed for rotary movement on a neck finish of a container, said snap-on closure comprising an end wall, a resilient peripheral skirt, and a crown, with a locking lug extending radially inwardly from said skirt in alignment in a fire position with a notch in the neck finish upon rotation of the snap-on closure to permit removal of said snap-on closure from said container only when in the fire position, and snap beads co-planar with the locking lug and extending inwardly from the skirt, said snap beads being longer than the notch is wide, a finger tab comprising indicium formed without sharp edges and corners and extending radially outwardly from said skirt in alignment with said locking lug, said snap beads camming over said locking ring and resiliently expanding said skirt and the locking lug passing over the locking ring upon snap locking the snap-on closure to the neck finish and upon removal of said snap-on closure, said locking lug and said snap beads being interengaged with said locking ring upon snap locking and said locking ring becoming disengaged from said locking ring upon the removal of said snap-on closure, said crown extending upwardly and outwardly from the end wall and the skirt to form a surface that provides leverage for removal of the closure from the container.

8. The closure of claim 7, wherein the indicia are formed of soft material.

9. The closure of claim 7, wherein the skirt further comprises having an accordion-like structure adjacent a lower peripheral edge thereof, and spaced apart from the locking lug and the snap beads to allow the skirt to flex from an initial unflexed position thereof radially outwardly and back to the initial position as said snap beads disengage from a locking ring on the container neck finish upon the removal of said snap-on closure and as said snap beads engage said locking ring upon the snap locking of the snap-on closure to the container neck finish.

10. The closure of claim 9, wherein the accordion-like structures are located adjacent the locking lug.

11. The closure of claim 7, wherein the crown has a diameter approximately equal to a diameter of the container.

12. The closure of claim 7, further comprising lugs extending inwardly at the top of the crown, wherein the snap-on closure can be inverted and attached to the container securely but without child resistance.