WO1992000889A1

WO1992000889A1 - Sealed snap top cap

Info

Publication number: WO1992000889A1
Application number: PCT/US1991/004933
Authority: WO
Inventors: James G. Finneran
Original assignee: J.G. Finneran Associates
Priority date: 1990-07-13
Filing date: 1991-07-12
Publication date: 1992-01-23
Also published as: CA2087262A1; EP0538388A1

Abstract

A container (10) and cap (1) combination adapted to form a securely sealed closure. The cap (1) is adapted with locking ribs (3) which engage a snap groove (13) between flanges (11) of the container (10). Three axially displaced lines (14, 16, 18), each with three points of contact between the cap (1) and the container (10) self-align the cap (1) on the container (10).

Description

- i -

SEALED SNAP TOP CAP

Field of the Invention

The invention relates to bottles, particularly laboratory sample bottles and dispensers for pharmaceuticals and medicinal agents. Typically, this type of dispenser requires a securely sealed cap which is presently accomplished with a standard snap cap and corresponding bottle neck finish. In the present invention, a variety of safe-guard caps may be used with one bottle.

Background

Many conventional containers have a standard snap cap and neck finish; most aspirin bottles utilize this type of container. In this basic snap cap design, the extended skirt of the cap secures under a protrusion on the neck of the vial such that there is one point of contact between the skirt and vial upon sealing the container. The protrusion on the neck of conventional vials is of increased mass, therefore dimensional tolerance is not closely controlled during the molding process. Furthermore, the basic snap cap design does not allow for self-aligning or secure retention of the cap and the vial. Also, the conventional design of the snap cap does not provide for ease of assembling the cap and the vial.

Another common closure for bottles of this type is a crimp cap, which is securely retained on the neck finish by the crimping of a metallic (usually aluminum) skirt under a lip on the neck of the bottle.

Conventional containers allow only one type of cap per container, requiring suppliers to maintain large inventories of several types of caps and several types of corresponding containers. These containers also are not conducive to simple industrial automation, as the only convenient means of handling the containers is with complicated and expensive equipment.

Brief Description of the Invention

In the present invention, there is provided a container and cap combination. Circumferentially displaced points of contact between the cap and the container at axially displaced lines provide self- alignment and secure retention of the cap and the container. The neck of the container includes a top flange and a lower flange with a snap groove between them. The resilient cap includes a top member and locking ribs which fit into the groove. The inner diameter of the cap and the container flanges on both axially displaced sides of said groove and locking ribs are of sufficiently small tolerance, as are said groove and rib inner diameters (preferably plus or minus 5 thousandths of an inch) to provide multiple axially displaced alignment means.

Brief Description of the Figures

Figure 1 illustrates a container and cap combination in accordance with the claimed invention;

Figure 2 is an expanded, cross-sectional view of the upper part of the cap-container combination shown in Figure l, taken along plane 2-2;

Figure 3 is similar to Figure 2 with the components dissembled; and

Figure 4 is a top view of the inside of the cap of the combination shown in Figure 1, taken along plane 4-4 of Figure 3.

Detailed Description of the Invention

As shown in Figs. 1 and 2, the present invention includes a container and cap combination 20, comprising container 10 and resilient cap l having an axis, a. Three lines of contact 14, 16 and 18 exist between cap l and container 10 which provide self- aligning and secure retention of cap 1 and container 10. Container 10 may be plastic or glass. Cap 1 is a resilient plastic. Now referring to details of this cap-container combination as better seen in Figs. 2-4, cap 1 includes top member 9 with a center opening 4. Cap 1 has the capacity to retain within itself liner 2 which may be composed of silicone rubber, butyl rubber, natural rubber or the like. Thus, liner 2 is resilient and underlies top member 9.

Cap skirt 5, the internal diameter of which corresponds to or is only slightly greater than the outer diameter of the neck of container 10, extends vertically downward from cap top 9 to cap lower flange 6 and facilitates alignment of cap 1 and container 10, as they are assembled. Four locking ribs 3 are located at circumferentially spaced locations around the inside of skirt 5 along contact line 16. Locking ribs 3 are placed at an axially intermediate height inside skirt 5 to provide, in combination with contact lines 14 and 18, alignment between cap 1 and container 10. The angular shape of locking ribs 3 also allows for tolerance variation of liner 2, ± 0.010 of an inch, thus accommodating thick and thin liners. Locking ribs 3, as shown in Fig. 4, retain liner 2 and provide the pull down and lock mechanism which seals container 10.

Circular ridge 26 extends from the underside of top member 9 of cap 1 and aligns with the neck of container 10. Circular ridge 26 applies a slight pressure to liner 2 urging liner 2 outward, thus more securely sealing container 10.

To facilitate alignment, as well as retention of cap 1 on container 10, the neck finish of container 10, includes upper flange 11 and lower flange 12, between which is disposed snap groove 13. When cap 1 is mounted on container 10 and force is applied to top member 9, locking ribs 3 expand past upper flange 11 and engage snap groove 13. Thus, snap groove 13 provides the pull down and lock mechanism in conjunction with locking ribs 3 which seals container 10. Ridge 26 also acts as a fulcrum, when ribs 3 are locked on snap groove 13 between upper flange and lower flange, 11 and 12, pulling downwardly on cap skirt 5.

There are three lines of contact 14, 16 and 18 between skirt 5 of cap 1 and the neck finish of container 10. Locking ribs 3 engage snap groove 13 thus defining line of contact 16, and the enlarged inner diameter of skirt 5 above and below ribs 3 contacts flanges 11 and

12, thus defining lines of contact 14 and 18. The three lines of contact self-align and securely retain cap 1 and container 10.

Also, the snap groove 13 between flanges 11 and

12 causes the neck finish of container 10 to be of reduced mass as compared to conventional neck finishes for receiving a self gripping cap. This facilitates tighter dimensional tolerance in the molding of the neck finish (yet permits mating with the self-aligning cap of the present invention and permits better gripping as well) because thermal expansion and contraction is controlled in the molding of the glass or plastic article. Therefore, closer dimensional tolerance is permitted as compared to conventional containers.

More importantly, the multiple axially displaced alignment features of the mating cap and neck finish of the present invention provide a self alignment. which in turn results in better, i.e. more secure, cap retention, as well as more secure seating and sealing of liner 2 between the mating opposing surfaces of cap l and the top of the neck finish of container 10. To best accomplish this, the dimensional tolerances of the opposing surfaces of the inner diameters of skirt 5 and the outer diameters of the container neck flanges 11, 12 and groove 13 are all tightly controlled, preferably to plus or minus 5 - 10 thousandths of an inch, most preferably 3 - 7 thousandths of an inch.

A crimp seal, not shown, composed of aluminum for example, may also be used to seal container 10 by securing the lower end of skirt 5, under lower flange 12 of container 10. Thus, the container of the claimed invention allows the user a choice of capping, cap 1 or a crimp seal, thus minimizing the container inventory required.

Preferably also, maximum vertical clearance between lower flange 6 of cap 1 and shoulder 8 of container 10 is provided most preferably at least 1/8 - 3/16 of an inch, to allow a point of contact 19, as seen in Fig. 2, for positioning container 10, either manually or by automated equipment, such as robotically.

While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and equivalent variations of this invention may be devised by those skilled in the art without departing from the true spirit and scope of this invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.

Claims

What is claimed is:

1. A container and cap combination adapted to form a securely sealed closure of said container, said combination comprising a container with a neck finish having an axially displaced top flange and an axially displaced lower flange with a groove therebetween said cap formed of a resilient plastic and including a top member and a dependent skirt adapted to surround said flanges and said groove and to mate therewith, with a plurality of locking ribs at an axially intermediate position and at circumferentially spaced locations around said groove, said ribs adapted upon downward movement of said cap over said top flange, to expand and then to contract into said groove, the axial distance from the bottom of said top member to the top of said ribs corresponding to that between the top of said neck finish and the bottom of said top flange.

2. The container and cap combination of claim

1 wherein said axial dimensions and the diametric dimensions of the opposed inner surfaces of said dependent skirt and the outer surfaces of said flanges and interposed groove being of sufficiently small tolerance to securely retain said cap on said container neck and in axial alignment therewith.

3. • The container and cap combination of claim 1 wherein said cap further includes a lower flange and said container further includes a shoulder, such that a maximum vertical clearance exists between said lower flange of said cap and said shoulder of said container as a point of contact for automated equipment.

4. The container and cap combination of claim 1 wherein said combination is adapted to form a securely sealed closure of said container via a pull down and lock mechanism.

5. The container and cap combination of claim 1 wherein said container is composed of material selected from the group consisting of glass and plastic.

6. The container and cap combination of claim

1 wherein said resilient material is plastic.

7. The container and cap combination of claim 1 wherein said cap further includes a liner, which underlies said top member.

8. The container and cap combination of claim 7 wherein the underside of said top member of said cap further includes a ridge, overlying the top of said neck finish.

9. The container and cap combination of claim 6 wherein said liner is composed of material selected from the group consisting of silicone rubber, butyl rubber and natural rubber.

10. A cap, formed of resilient material, comprising a top member and a dependent skirt, said dependent skirt having a plurality of locking ribs located at axially intermediate position and at circumferentially spaced locations around said skirt and adapted to engage a groove in the neck of a container upon downward movement of said cap onto said container.

11. The cap of claim 10 wherein said top member is adapted to retain a liner under said top member.

12. The cap of claim 10 further including a circular ridge on the underside of said top member.

13. A container, comprising a neck finish with an axially displaced top flange and an axially displaced lower flange, with a groove therebetween, said groove adapted to accept locking ribs of a cap upon downward movement of said cap onto said container.