WO1993011053A1

WO1993011053A1 - Sealed snap top cap with locking collar and pull tab

Info

Publication number: WO1993011053A1
Application number: PCT/US1992/010442
Authority: WO
Inventors: James G. Finneran
Original assignee: J.G. Finneran Associates
Priority date: 1991-12-02
Filing date: 1992-11-30
Publication date: 1993-06-10

Abstract

A cap (1) adapted to form a securely sealed closure when used in combination (20) with a container (10). The cap (1) has locking ribs (3) which engage a snap groove (13) between flanges (11, 12) of the container (10). Three axially displaced lines define three points of contact (14, 16, 18) between the cap (1) and the container (10) and self-align the cap (1) on the container (10). In addition, a locking collar (30) can be placed over the cap (1) to increase the pressure at the three points of contact (14, 16, 18). A pull tab (60) can be used in conjunction with the cap (1) (with or without the locking collar (30)) to facilitate removal of the cap (1) from the container (10).

Description

SEALED SNAP TOP CAP WITH LOCKING COLLAR AND PULL TAB

Field of the Invention

The invention relates to bottles, particularly laboratory sample bottles and dispensers for injectable pharmaceuticals and medicinal agents. Typically, this type of dispenser requires a securely sealed cap which is presently accomplished with a standard snap cap or a crimped aluminum cap and corresponding bottle neck finish. In the present invention, a more secure snap cap and mating neck finish is provided, the neck finish also facilitating use of the same bottle with a conventional crimped aluminum cap.

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. In addition, those designs which have more than one point of contact do not generally have tight dimensional tolerances between the cap and container contact points. Moreover, the materials used to form the cap and container are not very rigid so that, even with multiple points of contact, the designs cannot provide a seal able to withstand contents under high pressure or provide for long term storage without leakage. 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 or for ease of removing the cap from 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 a cap (optionally with locking collar, a pull tab, or both) . 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 angular locking ribs which fit into the groove. The inner diameter of the cap and the container flanges on both axially displaced sides of the groove and angular- locking ribs are of sufficiently small tolerance, as are the groove and angular locking rib inner diameters (preferably plus or minus 5 thousandths of an inch) to provide multiple axially displaced alignment means.

Optionally, a collar can be used in conjunction with the cap and container to increase the radial pressure against the points of contact between the cap and container. The collar is basically a sleeve which slips over the cap urging the skirt of the cap inward to enhance the engagement between the cap and the bottle. This collar can be formed integrally with the cap and detachably secured thereto so that after the cap is snapped onto the container, the collar is separated from the cap and slid into position over the skirt of the cap by the use of axially downward pressure on the collar when the cap is placed on the container. The collar can also be formed separately, allowing the collar to be a more rigid material and thus enhancing the radial pressure exerted by the collar against the cap towards the container. The collar may also be a preselected color for container identification purposes.

Also optionally, a pull tab can be used in conjunction with the cap (with or without the locking collar) and container to facilitate removal of the cap from the container.

Brief Description of the Figures

FIG. 1 illustrates a container and cap combination in accordance with the claimed invention; FIG. 2 is an expanded, cross-sectional view of the upper part of the ca -container combination shown in FIG. 1, taken along plane 2-2;

FIG. 3 is similar to FIG. 2 with the components dissembled;

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

FIG. 5 is an expanded cross-sectional view of the upper part of the container of the present invention with the alternative crimp cap for which it is adapted;

FIG. 6 is an expanded cross-sectional view of the crimp cap prior to assembly;

FIG. 7 is an expanded cross-sectional view of the cap-container combination with collar in accordance with the claimed invention;

FIG. 8 is an expanded cross-sectional view of the one piece cap with optional collar placed on the container just prior to assembly therewith to effect sealing of the container;

FIG. 9 is bottom view of the one piece cap with collar taken along the plane 9-9 of FIG. 8;

FIG. 10 is a side view of a cap-container combination with collar in accordance with the claimed ^■ invention;

FIG. 11 is an expanded view of a cap with a collar partially slid over the cap;

FIG. 12 is an expanded view of a separate collar; FIG. 13A is a top view of a cap without a collar but with a pull tab; FIG. 13B is a side view the cap shown in FIG. 13A;

FIG. 13C is side view, in partial cross- section, of a cap-container combination with a cap pull tab in accordance with the claimed invention, taken along plane 13C-13C of FIG. 13A;

FIG. 14A is a side view of a cap with a pull tab in the closed position;

FIG. 14B is a side view of a cap-container combination with a pull tab in the open position;

FIG. 14C is a front view of a cap with a pull tab in the open position;

FIG. 15A is a top view of a cap with both a collar and a pull tab; and FIG. 15B is side view, in partial cross- section, of a cap-container combination with a cap pull tab in accordance with the claimed invention, taken along plane 15B-15B of FIG. 15A.

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 1 having an axis, a. Three lines of contact 14, 16, and 18 exist between cap 1 and container 10 which provide self- aligning and secure retention of cap 1 and container 10. Container 10 may be plastic, glass, or other similar material. Cap 1 is a resilient material such as 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. It is possible to access the contents of container 10 without removal of cap 1 by, for example, inserting a syringe into center opening 4 and through perforatable liner 2.

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 (axially) downward from cap top member 9 to cap lower end 6, to be substantially flush laterally with the bottom of the lower flange 12 of container 10, and facilitates alignment of cap 1 and container 10 as they are assembled. Four angular locking ribs 3 project from skirt 5 and 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 in 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, formed between the apex of each rib 3 and the inner surface of groove 13, 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. (Although the top angled surface of each rib 3 may engage under flange 11, depending on the dimensions of the various components and, specifically, of the liner 2, such engagement is viewed as a continuation of contact line 14 and not as a discrete line of contact.) The three lines of contact self-align and securely retain cap 1 and container 10..

The snap groove 13 has a substantially rectangular cross-section (rectangular with some latitude allowed for tolerance variation) , formed between the top flange 11 and the lower flange 12, to accept locking ribs 3 while allowing tolerance variation upon downward movement of cap 1 onto 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 5 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 1 and

10 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

15 plus or minus 5-10 thousandths of an inch, most preferably 3-7 thousandths of an inch.

A cap with a crimp seal 53, as shown in FIG. 6, composed of aluminum, for example, may also be used to seal container 10 by securing the lower end 6 of skirt 5, •20 as shown in FIG. 5, under lower flange 12 of container

10. The skirt 5 of the crimp seal 53 provides two points of contact, 14 and 18, between the skirt 5 and the upper flange 11 and the lower flange 12 of the container 10 in addition to the point of contact between the lower end 6 25 of the crimp cap skirt 5 and the bottom of lower flange 12.

Thus, the container of the claimed invention allows the user a choice of capping, cap 1 or a crimp seal 53, thus minimizing the container inventory 30 required.

FIGS. 7-12 show the use of a collar 30 in conjunction with a cap 1, where FIGS. 7-9 show a one- piece cap with collar 37 and FIGS. 10-12 show the use of a separate collar 30 or the use of the collar 30 shown in 35 FIGS. 7-9 once detached from the cap 1. FIG. 7 is a detailed view of the configuration of the container 10, cap 1, and collar 30 in combination. As shown in FIG. 7, the use of the collar creates an area of continuous contact 33 around the entire circumference of the cap 1, from the upper edge 31 of the collar 30 to the lower edge 32 of the collar 30. The continuous contact 33 provides radial pressure against the cap 1 and from the cap 1 against the container 10 since the inner diameter 35 of the collar 30 is slightly smaller than, but in tight tolerance with, the outer diameter of the cap 1.

In detail, the continuous contact 33 enhances the perpendicular pressure, relative to axis a, of the three points of contact, 14, 16, and 18, between the cap 1 and the container 10. The additional pressure against the points of contact increases the ability of the container-cap combination 20 to withstand high internal pressure and improves sealability for long term storage.

FIG. 7 shows the upper edge 31 of the collar 30 flush with the top member 9 of the cap 1 and the lower edge 32 of the collar 30 even with the bottom of the angular locking ribs 3 on the inner diameter of the cap 1. The upper edge 31 of the collar 30 could be placed in a range of positions along the cap, from the top of the angular locking ribs 3 on the inner diameter of the cap 1 to the top member 9 of the cap 1, and the lower edge 32 of the collar 30 could be placed in a range of positions along the cap, from the bottom of the angular locking ribs 3 on the inner diameter of the cap 1 to the lower end 6 of the cap 1, while still providing increased perpendicular pressure to the three contact points between the cap 1 and the container 10--although the amount of pressure could vary as a function of the choice of positions chosen for the lower and upper edge of the collar, 31 and 32. On the lower edge 32 of the collar 30 there can be a tab 36. The tab 36 is used to allow pulling on (for easy assembly) or pushing off (for easy removal) of either the cap 1 and collar 30 at one time or just the 5 collar 30 by a user or automated equipment.

FIGS. 8 and 9 illustrate an exemplary form of a one-piece cap with collar 37. FIG. 8 shows the one-piece cap with collar 37 placed on the container 10 in preparation for sealing the container 10 by snapping the

10 cap 1 over the container 10. FIG. 9 shows an exemplary method of detachably securing the ^"collar 30 to the cap 1. The collar 30 in FIG. 9 is attached to the cap 1 by tabs 34. The collar 30 could also be attached to the cap 1 by a continuous membrane, or a continuous membrane with a

15 thin score line.

The securing means described above allows the user or automated equipment, by placing downward axial pressure on the entire upper edge 31 of the collar 30, to: snap the cap 1 onto the container 10, separate the

2.0 collar 30 from the cap 1, and slide the collar 30 into position alongside ^"the cap 1 with only one, single, downward action. This allows the cap 1 and collar 30 to seal the container 10 with only one operation. The one- piece cap with collar 37 is formed in a single molding 5 operation and, thus, is of the same material.

FIGS. 10-12 show an exemplary use of a separate collar 30, or a collar 30 as shown in FIGS. 7-9 once detached from the cap 1, to enhance the points of contact between the cap 1 and the container 10. FIG. 10 shows 0 the collar 30 in place over the cap 1 and is similar to FIG. 7. FIG. 11 shows a version of the cap and a separately formed collar, or a collar 30 as shown in FIGS. 7-9 once detached from the cap 1, where the combination is preassembled. FIG. 12 shows an exemplary separately formed collar 30 or a collar 30 as shown in FIGS. 7-9 once detached from the cap 1.

There are additional advantages to the use of a separately formed collar in conjunction with the cap and container combination 20 described above. The separately formed collar 30 can be formed of more rigid material than the cap 1, thereby increasing the radial pressure when the collar 30 is in position, thus further enhancing the sealability of the container 10 and the long-term storage potential. The separately formed collar 30 may also be a pre-selected color for container content identification purposes.

Preferably, the cap and container combination 20, with or without a collar 30, should have a maximum vertical clearance between lower end 6 of cap 1 and shoulder 8 of container 10 of 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 robo ically) . Turning to FIGS. 13A-15B, the cap-container combination 20 is illustrated with a pull tab 60. The reason for providing pull tab 60 is as follows.

To provide an adequate seal between cap 1 and container 10, especially when highly volatile solvents will be stored, a solvent-resistant material such as polypropylene must be used to form cap 1. Container 10 is formed of glass, plastic, or the like--as described above. The cap-container combination 20 is assembled by aligning cap 1 with the top surface 7 of container 10 (see FIG. 3) and applying downward pressure on cap 1.

Such downward pressure enables locking ribs 3 to expand past upper flange 11 and to engage snap groove 13. With locking ribs 3 engaging snap groove 13, liner 2 seals against top surface 7 of container 10. The user can accomplish such assembly of the cap-container combination 20 with relative ease using, for example, the thumb. Automated equipment could also be used to assemble the cap-container combination 20.

The seal formed between cap 1 and container 10 often is so good, however, that a problem arises: removal of cap 1 from container 10 is difficult. The user may be unable to push upward (using, for example, the thumb) on the cap lower end 6 with sufficient force to disengage locking ribs 3 from snap groove 13. Consequently, an external tool, such as a bottle opener, pliers, or the like, may be required to generate the force required. Of course, automated equipment would overcome the removal problem created by the excellent seal.

To facilitate removal of cap 1 from container 10 by the user, a pull tab 60 is provided. Pull tab 60 may be molded integrally with cap 1. If so, the preferable molding position of pull tab 60 relative to cap 1 is shown by the dashed lines in FIG. 13C. Thus, pull tab 60 may be of the same material as cap 1. Pull tab 60 has a central locking ring 62.

When pull tab 60 is in its closed position, as shown in FIGS. 13A, .13C, and 14A, locking ring 62 frictionally fits within opening 4 in cap 1. The friction fit between locking ring 62 and opening 4 holds pull tab 60 in place over cap-container combination 20.

Pull tab 60 has an outer rim 64 which extends laterally beyond top member 9 of cap 1. The user can easily push upward on outer rim 64 (using, for example, the thumb) to remove locking ring 62 from opening 4. Such action will displace pull tab 60 along the path of arrow "A¹¹ in FIG. 13C, from its closed position (shown in solid lines) to an open position (shown in dashed lines) .

Once locking ring 62 disengages opening 4, and preferably when pull tab 60 is in a completely vertical position parallel to axis a (as shown in FIGS. 14B and 14C) , the user can pull upward on pull tab 60 in the direction of arrow "B" in FIG. 14B. Pull tab 60 allows the user to generate more upward force than was possible without pull tab 60. Consequently, the user can displace locking ribs 3 from snap groove 13, thereby disengaging cap 1 from container 10, without the need for external tools.

For many applications, cap 1 is removed from container 10 only once; cap 1 is not required to re-seal container 10 after container 10 is first opened. Especially for such applications, cap 1 may be provided with one or more tear grooves 66 defining a tear ring 68. Tear ring 68 may be integrally formed with pull tab 60. Once locking ring 62 disengages opening 4, and preferably when pull tab 60 is in a completely vertical position parallel to axis a (as shown in FIGS. 14B and 14C) , the user can pull downward on pull tab 60 in the direction of arrow "C" in FIG. 14B. The downward force on pull tab 60 breaks tear ring 68 along tear grooves 66 (which are weaker than the remainder of cap 1) . Because cap 1 then has a gap where tear ring 68 has been removed, cap 1 can easily be removed from container 10.

Pull tab 60 on cap 1, described above with reference to FIGS. 13A-14C for a cap-container combination 20 without a collar 30, can also be applied to a cap-container combination 20 with a collar 30--as shown in FIGS. 15A and 15B. Collar 30 is preferably made of a relatively rigid material, such as polypropylene, enabling collar 30 to apply circumferential pressure against the softer and more resilient material of cap 1 (which is, for example, low density polyethylene) . Pull tab 60 may be molded integrally with collar 30. Thus, pull tab 60 may be of the same material as collar 30. Collar 30 can be removed from cap 1 by pushing upward on outer rim 64 of pull tab 60, until locking ring 62 disengages opening 4, and then pulling upward on pull tab 60 until collar 30 is removed from cap 1. Because cap 1 is typically formed of a resilient material when used with collar 30, slight upward pressure against cap 1 will enable the user to remove cap 1 from container 10 once collar 30 is removed from cap 1.

Collar 30 may also be provided with tear grooves 66 defining a tear ring 68, as described above. Tear grooves 66 and tear ring 68 allow the user to break collar 30 upon exerting downward pressure on pull tab 60. Note that, as described above, collar 30 (with or without pull tab 60) may be preassembled with cap 1 or added later.

Although 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 cap having a vertical axis and an outer diameter and adapted for combination with a container which has a neck finish including a top flange, a lower flange with a bottom, and a groove formed between said flanges, said cap formed of resilient material and comprising: (a) a top member having an underside, and (b) a dependent skirt, said dependent skirt: (i) extending axially downward to be substantially flush laterally with said bottom of said lower flange of said container upon completed downward movement of said cap onto said container, (ii) having a first substantially flat surface disposed concentrically with said vertical axis for engaging said upper flange of said container, a second substantially flat surface located axially below said first surface and disposed concentrically with said vertical axis for engaging said lower flange of said container, and a plurality of angular locking ribs located at an axially intermediate position between said first and second surfaces and at circumferentially spaced locations around said skirt and adapted to engage said groove in said neck finish of said container upon downward movement of said cap onto said container, and (iii) being sufficiently stiff to effect alignment and sealing engagement with said container by contact above, at, and below said locking ribs.

2. The cap as recited in claim 1 further including a resilient liner disposed between said angular locking ribs and said top member.

3. The cap as recited in claim 2 wherein said liner is disk-shaped, perforatable, and composed of a material selected from the group consisting of silicone rubber, butyl rubber, and natural rubber.

4. The cap as recited in claim 1 further including a circular ridge on the underside of said top member.

5. The cap as recited in claim 1 in combination with a collar adapted to surround and frictionally engage the outer diameter of said cap, said collar being adapted thereby to exert inward pressure on said cap.

6. The cap as recited in claim 5 wherein said collar is made of a more rigid material than said cap.

7. The cap as recited in claim 5 wherein said collar is made of the same material as said cap.

8. The cap as recited in claim 5 wherein said collar is different in color from said cap.

9. The cap as recited in claim 5 wherein said collar includes a pull-on/push-off tab.

10. The cap as recited in claim 1 further including a pull tab facilitating disengagement of said angular locking ribs from said groove in said neck finish of said container.

11. The cap as recited in claim 10 wherein said pull tab is integral with said cap.

12. The cap as recited in claim 10 wherein said pull tab is made of the same material as said cap.

13. The cap as recited in claim 10 wherein said top member has a central opening and said pull tab has a central locking ring adapted to frictionally engage said opening when said pull tab is in its closed position.

14. The cap as recited in claim 10 wherein said pull tab has an outer rim extending laterally beyond said top member.

15. The cap as recited in claim 10 further including a breakable tear ring defined by tear grooves, said tear ring integrally formed with said pull tab.

16. The cap as recited in claim 5 further including a pull tab facilitating disengagement of said collar from said cap.

17. The cap as recited in claim 16 wherein said pull tab is integral with said collar.

18. The cap as recited in claim 16 wherein said pull tab is made of the same material as said collar.

19. The cap as recited in claim 16 wherein said top member has a central opening and said pull tab has a central locking ring adapted to frictionally engage said opening when said pull tab is in its closed position.

20. The cap as recited in claim 16 wherein said pull tab has an outer rim extending laterally beyond said top member.

21. The cap as recited in claim 16 wherein said collar has a breakable tear ring defined by tear grooves and said tear ring is integrally formed with said pull tab.

22. A cap adapted for combination with a container which has a groove, said cap formed of resilient material and comprising: (a) a top member; (b) a dependent skirt having an outer diameter and a plurality of angular locking ribs located at an axially intermediate position and at circumferentially spaced locations around said skirt and adapted to engage said groove in said container upon downward movement of said cap onto said container, said dependent skirt being sufficiently stiff to effect- alignment and sealing engagement with said container by contact above and below said locking ribs; (c) a resilient rubber disk-shaped liner disposed between said angular locking ribs and said top member; and (d) a collar member above said top member and detachably secured thereto and adapted upon separation from said top member to matingly engage said outer diameter of said skirt and exert inward pressure thereon.

23. The cap as recited in claim 22 detachably secured to said collar by a connecting member adapted to fracture under a predetermined axial force downward on said collar.

24. The cap as recited in claim 23, said cap adapted to mate with said container by a predetermined downward axial snap-on force on said cap, said predetermined downward axial snap-on force is less then said connecting member fracture force.

25. A cap as recited in claim 22 wherein said cap and attached collar member comprise a unitary molded body.