US20020144971A1

US20020144971A1 - Sealing disc with flexible annular ring

Info

Publication number: US20020144971A1
Application number: US09/826,075
Authority: US
Inventors: Clas Nilstoft; Todd Mathes
Original assignee: Silgan Plastic Food Containers Corp
Current assignee: Silgan Plastic Food Containers Corp
Priority date: 2001-04-04
Filing date: 2001-04-04
Publication date: 2002-10-10
Also published as: CN1378957A

Abstract

A closure for a container consists of a top wall with an annular skirt depending therefrom and extending downwardly to a terminating edge. An inner surface of the annular skirt has a retaining bead in an upper portion of the inner wall. If threads are to used on a finished closure, then such threads, as desired, replace the retaining bead. Additionally, the top wall has a flexible annular ring formed axially along an inner surface and depending downwardly therefrom and spaced inwardly of the skirt. A sealing disc is disposed above the retaining bead and below the flexible annular ring. The flexible annular ring has a diameter larger than the inner diameter of the retaining bead. Furthermore, the flexible annular ring is the same diameter as a container rim of a container to be sealed by the closure of the present invention. Another preferred closure substitutes a glue post mounted along an inner surface of the top wall for the retaining bead in order to attach the sealing disc to the inside of the closure.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to safety closures for use on containers which remain sealed during the backing up of the closure onto a container. More particularly, this invention relates to providing a sealing disc on a closure which is held in place by a retaining bead formed on an upper portion of an interior of a side wall of the closure.

2. Discussion of the Prior Art

Current closures with sealing features often utilize some form of sealing disc. In addition, some closures utilize retaining beads or the like to keep the sealing disc from falling out upon opening. Some current closures have an annular ring of a narrower diameter than the neck and therefore not generally in line with a sealing land on an upper surface of the container neck. Such an annular ring is formed in order to secure the sealing disc onto the neck. A closure of the type as taught in FIG. 2 of U.S. Pat. No. 4,460,428 to Chang displays visible distortion to the sealing disc by virtue of the fact that its annular ring is of a smaller diameter than the neck diameter of the corresponding container. Such distortion can result in leaks as the closure is backed down to lock. Because of this fact, if sealing is desired after the closure is fully locked onto the container, the sealing disc must be made thicker and therefore more resistant to unwanted distortion as a result of mismatch of diameters. Therefore, there is a need for a closure which provides for physical alignment of structural parts which reduces distortion of sealing discs and which as a consequence includes thinner sealing discs which are less expensive to manufacture and easier to produce than those found currently in the art.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a sealing disc on a closure for a container which is held in place by a retaining mechanism formed on an upper portion of an inner side wall of the closure.

Another object of the present invention is to provide a closure which has a flexible annular ring fixedly attached inside the top of the closure wherein the flexible annular ring is aligned directly over a container lip, thereby keeping the seal in contact with the container lip as the closure backs up to lock onto the container.

An even further object of the present invention is to provide a closure for a container which includes said retaining mechanism being a glue post.

A further object of the present invention is to provide a closure for a container including a retaining mechanism being either a retaining bead or a glue post and which includes helical threads formed on an interior of a side wall and which correspondingly mate to threads formed on a container neck finish.

Yet another object of the present invention is to provide a closure for a container including a retaining mechanism being either a glue post or an upper surface of helical threads formed on an interior of a side wall and which correspondingly mate to threads formed on a container neck finish.

More particularly, the present invention provides a sealing disc on a closure which is held in place by a retaining mechanism formed on an upper portion of an inner side wall of the closure. The closure can be either a single-wall or double-wall closure, as desired. The retaining mechanism is preferably a retaining bead. However, another preferred embodiment includes helical threads formed upon the closure. An upper surface of the helical threads of such a closure may serve, as desired, either as a replacement for a retaining bead, or in combination with a retaining bead, as the retaining mechanism to secure the sealing liner within the closure.

A flexible annular ring is fixedly attached inside the top of the closure wherein the flexible annular ring holds the sealing disc in contacting relation with a container rim in order to seal the container as the closure backs up to lock. The flexible annular ring is placed inside the top of the closure in direct vertical alignment with the container rim. The flexible annular ring is of the same diameter as the container rim. Of particular benefit, less leakage past the sealing disc occurs due to minimal distortion of the sealing disc as the closure backs up to lock. Alternatively, a glue post is used as a retaining mechanism instead of a retaining bead in order to secure the sealing disc to the closure. Closures of the present invention incorporate helical threads, locking lugs, and other structure in order to fasten the closure to the container. Additionally, closures having features of the present invention are further fitted with tamper-indicating and child resistant structure as required.

Further objects and advantages of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings forming a part of the specification wherein like reference characters designate corresponding parts into several views.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein: [0013]
FIG. 1 is a perspective view of a preferred closure of the present invention; [0014]
FIG. 2 is a sectional view of FIG. 1 taken along lines [0015] 2-2 and, additionally, with a container neck shown in contacting relation with the closure for clarity;
FIG. 3 is a sectional view of another preferred closure of the present invention; [0016]
FIG. 4 is a sectional view of another preferred closure of the present invention; [0017]
FIG. 5 is a sectional view of another closure of the present invention wherein the sealing disc is annular; and, [0018]
FIG. 6 is a top view of the annular disc shown in FIG. 5.[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the FIGS. is shown a [0020] closure 10 formed in accordance with the present invention. Closure 10 may be single-wall or double-wall, as desired. FIG. 2 shows a single-wall closure 10 having a top wall 12, and an annular skirt 11 depending therefrom and extending downwardly to a terminating edge. It is clear that if a double-wall closure is desired, then the annular skirt 11 described above and hereinafter is actually an inner wall of such a double-wall closure 10.
The [0021] annular skirt 11 includes an outer surface 14 and an inner surface 16. A circumferentially extending retaining mechanism such as a retaining bead 20 is disposed along an upper portion of the inner surface 16.
If an embodiment of the [0022] closure 10 is intended to have threads 50 as shown in FIG. 4, then the threads 50 themselves serve, as desired, as the retaining mechanism, and the retaining bead 20 is not necessary on such an embodiment.
Referring back to FIG. 2, a flexible [0023] annular ring 18 is formed axially inside the top wall 12 and extending downward therefrom with its downwardmost edge pointing inwards towards the center of the closure 10. A sealing disc 30 is located below, but in contact with flexible annular ring 18, and above, but in initial contact with the retaining bead 20. The sealing disc 30 is placed in contacting relation with a container rim 42 in order to seal a container 40 as the closure 10 backs up to lock. As the closure 10 backs up to lock, the annular skirt 11 may move downwards in relation to the location of the sealing disc 30 when the closure 10 is not fastened to the container 40. As such motion occurs, the retaining bead 20 may move down and away from the sealing disc 30. The seal between the closure 10 and the container 40 remains unbroken throughout this axial movement due to the downward pressure exerted upon the sealing disc 30 by the flexible annular ring 18. In fact, such downward pressure increases as the closure 10 backs up to lock and the annular skirt 11 moves downwards in relation to the location of the sealing disc 30 which is seated on the container rim 42.
As shown in FIG. 3, an alternative embodiment of a closure of the present invention utilizes a [0024] glue post 22 instead of a retaining bead 20 of FIGS. 1 and 2. The glue post is shown as a projection downwards from a surface of the top wall 12, and positioned axially inside of the flexible annular ring 18. Ideally, the glue post 22 projects downwards only so far as to allow the flexible annular ring 18 to exert enough pressure on the sealing disc 30 to create and maintain a seal between the closure 10 and the container 40. Adhesives and methods including induction sealing are used to secure the sealing disc 30 to the glue post 22.
FIG. 4 shows a closure which utilizes threads [0025] 50 in place of the retaining bead 20 of FIGS. 1 and 2, or the glue post 22 of FIG. 3. The threads 50 are formed to correspond with container threads 44, as desired, and so that they retain the sealing disc 30 inside of the closure 10. Such threads 50 include helical threads, as desired.
In a preferred embodiment, the diameter of the flexible [0026] annular ring 18 is the same as the diameter of the container rim 42 in order to minimize distortion of the rotary sealing liner 30. Without such distortion, the sealing disc 30 is allowably thinner and thereby more readily inserted into the closure 10 during manufacture.
As depicted in FIGS. 5 and 6, alternatively the [0027] sealing disc 130 may be annular with an opening 126 centrally formed therein. The post 122 of the closure 100 may extend downward through the opening 126. Retention bead 120 may be formed on the interior side wall of the closure to hold the sealing disc 130 in place. Matching retention bead 124 may extend outwardly from the post 122 in order to contact the underside interior portion of the sealing disc adjacent the opening 126. Bead 124 may also be utilized to seal internally the neck 40 of the container. As in the prior embodiments, ring 18 extends downwardly and contacts the top surface of the ring 130 and compresses it against the top rim 42 of the container.
The detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention and scope of the appended claims. [0028]

Claims

What is claimed is:

1. A closure for a container comprising:

a top wall with an annular skirt depending therefrom and extending downwardly to a terminating edge;

an inner surface of said annular skirt having a retaining mechanism;

said top wall having a flexible annular ring formed along an inner surface and depending downwardly therefrom, said flexible annular ring spaced inwardly of said skirt;

a sealing disc disposed above said retaining mechanism and below said flexible annular ring.

2. The closure for a container of claim 1, said retaining mechanism being a retaining bead.

3. The closure for a container of claim 1, said retaining mechanism being an upper surface of at least one thread formed on an upper portion of said inner wall.

4. The closure for a container of claim 3, said thread including at least one helical thread.

5. The closure for a container of claim 1, said flexible annular ring compressively contacting an upper surface of a container neck.

6. The closure of claim 1 wherein said sealing disc has a diameter which is larger than an inner diameter of said retaining mechanism.

7. The closure of claim 1 further comprising a central post extending downward from said top wall, said sealing disc having an aperture formed centrally there through, said central post extending through said aperture.

8. The closure of claim 7 wherein said retention mechanism further comprises an outwardly extending bead extending from said central post and contacting a lower interior surface of said sealing disc.

9. A closure for a container comprising:

a top wall with an annular skirt depending therefrom and extending downwardly to a terminating edge, said top wall having an inner surface;

an inner surface of said annular skirt having a retaining mechanism;

a compressible annular ring formed on said top wall inner surface and depending downwardly therefrom, said compressible annular ring spaced inwardly of said skirt;

a downwardly extending central post formed on said top wall inner surface interior from said compressible annular ring;

a sealing disc disposed above said retaining mechanism and below said flexible annular ring and having an aperture formed therethrough;

said post extending through said aperture in said sealing disc.

10. A closure for a container, said closure consisting of:

said top wall having a flexible annular ring formed along an inner surface and depending downwardly therefrom;

said top wall of said closure having a post located on an inner surface of said top wall, said post depending downwardly therefrom, and located inboard of said flexible annular ring;

a sealing disc attached to said post and below said flexible annular ring;

said sealing disc having a diameter larger than said flexible annular ring.

11. The closure for a container of claim 10, said flexible annular ring having a diameter equal to a diameter of a container rim of a container to be sealed by said closure.