US3842574A

US3842574A - Method for applying a container closure

Info

Publication number: US3842574A
Application number: US00380207A
Authority: US
Inventors: J Dickey
Original assignee: Aluminum Company of America
Current assignee: Howmet Aerospace Inc
Priority date: 1971-12-27
Filing date: 1973-07-18
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

A container closure having a top end wall and a depending peripheral skirt which includes an outwardly projecting land with sealing material disposed on its under surface is positioned on a container entrance mouth which has inclined closure retaining means thereon and an outwardly projecting bead below the retaining means, the closure skirt is deformed against the inclined closure retaining means on the container mouth, substantially downward pressure is applied against the closure skirt overlying the container bead to press the sealing material in the closure skirt against the container bead, and a lower edge of the closure skirt is turned under the container bead to maintain pressure between the sealing liner and the container bead.

Description

[11 3,842,574 1 Oct. 22, 1974 1 1 METHOD FOR APPLYING A CONTAINER CLOSURE [75] Inventor: John J. Dickey, Richmond, 1nd.

{731 Assignee: Aluminum Company of America, Pittsburgh, Pa.

[22] Filed: July 18, 1973 [21] Appl. No.: 380,207

Related US. Application Data [62] Division of Ser. No. 212.235, Dec. 27, 1971, Pat. No.

3,479,790 11/1969 Barge 53/42 3,645,062 2/1972 Hannon ..53/42 Primary ExaminerRichard J. Herbst Attorney, Agent, or FirmDavid W. Brownlee l 5 7 1 ABSTRACT A container closure having a top end wall and a depending peripheral skirt which includes an outwardly projecting land with sealing material disposed on its under surface is positioned on a container entrance mouth which has inclined closure retaining means thereon and an outwardly projecting bead below the retaining means, the closure skirt is deformed against the inclined closure retaining means on the container mouth, substantially downward pressure is applied against the closure skirt overlying the container bead to press the sealing material in the closure skirt against the container bead, and a lower edge of the closure skirt is turned under the container bead to maintain pressure between the sealing liner and the container head.

3 Claims, 5 Drawing Figures METHOD FOR APPLYING A CONTAINER CLOSURE This is a division of application Ser. No. 212,235, tiled Dec. 27, I971, which has now issued as U.S. Pat. No. 3,771,683 on Nov. l3, 1973.

BACKGROUND OF THE INVENTION In closing a container with a closure or cap, it is conventional to provide a gasket or seal which seals the container against escape of the container contents and against entry of contaminants. This seal may be provided in a number of locations, with the usual seal being provided near the mouth opening of the container and with retaining means on the container and closure outwardly of the seal. Other combinations have provided a seal below the retaining means so that contaminants cannot collect in the closure around the retaining means in the combination. It is also known as disclosed in US. Pat. Nos. 3,286,868 and 3,286,867 to provide two sealing gaskets, one of which seals the closure against the container adjacent the container mouth opening and the other of which seals the closure against the container outwardly of the closure retaining means. As described in those patents, the dual sealing means prevents insect infestation into the area of the retaining means and also prevents the contents of the container from collecting on the retaining means.

Although the closure container combinations described in U.S. Pat. Nos. 3,286,868 and 3,286,867 have been useful in preventing infestation into the area of the retaining means, the outer seal in this combination may not prevent water or other gaseous or liquid contaminants from reaching the area of the retaining means when the exterior of the sealed container is exposed to a relatively high pressure as happens when such a combination is subjected to autoclaving by high pressure steam or the like. Accordingly, an improved closure-container combination is desired which will provide a high pressure seal on both sides of the closure retaining means to substantially preclude contamination of the contents of the container and the retaining means.

SUMMARY OF THE INVENTION This invention provides a closure which has a top end wall and a depending peripheral skirt therearound with sealing material on the inner surface of the skirt near its bottom edge and which is applied to a container entrance mouth having inclined closure retaining means thereon and an outwardly projecting bead below the retaining means by deforming the closure skirt against the closure retaining means, applying substantially downward pressure against the closure skirt overlying the container head to press the sealing material against such container bead, and turning a lower edge of the closure skirt under the container bead to maintain pressure between the sealing material and the container bead.

Accordingly, an object of the invention is to provide a container closure which can be applied to a container entrance mouth with high pressure hermetic seals on both sides of the closure retaining means.

Another object of the invention is to provide a closure having a depending peripheral skirt with a ring of sealing material on its inner surface which is pressed against a bead on a container mouth below closure retaining means thereon to provide a hermetic seal outwardly of the closure retaining means on the container.

Another object of the invention is to provide a method of applying a closure to a container by deforming the closure skirt against retaining means on the container mouth and pressing a ring of sealing material around the inner surface of the closure skirt against a container bead below the closure retaining means and turning a lower edge of the closure skirt under the container bead.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the invention will be more fully understood and appreciated with reference to the following description and the drawings attached thereto:

FIG. 1 is a cross sectional view of a preferred embodiment of a closure of the invention on a container entrance mouth prior to sealing;

FIG. 2 is a cross sectional view similar to FIG. 1 illustrating deforming of the closure skirt against closure retaining means on the container entrance mouth;

FIG. 3 is a cross sectional view similar to FIGS. 1 and 2 illustrating the application of top pressure against a shoulder on the closure skirt to press sealing material in the skirt against a bead on the container entrance mouth;

FIG. 4 is a cross sectional view similar to FIGS. 1-3 illustrating turning of a lower edge of the closure skirt under the bead on the container entrance mouth; and

FIG. 5 is a cross sectional view similar to FIGS. 1-4 illustrating a sealed closure container combination.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION A preferred embodiment of the invention is illustrated and described as comprising as a roll-on pilferproof closure which is particularly adapted for sealing a container for intravenous solutions for hospital use.

Referring more particularly to FIGS. l-5, FIG. 1 illustrates a closure 10 formed from sheet metal or other permanently deformable material, and preferably from sheet aluminum, which is loosely positioned over an entrance mouth 12 of a container 14. Container 14 is preferably comprised of glass although other permanently moldable materials known to the container industry such as plastic and metal may be utilized. Container 14 has an entrance mouth 12 with inclined retaining means 16 thereon, which are threads in the preferred embodiment although other commonly known retaining means may be used. A circumferential bead 18 is disposed below the retaining means 16 and preferably extends outwardly from the container main body beyond the inclined retaining means 16 although this is not considered to be critical of the invention. Bead 18 is essentially rectangular in cross section having a relatively small radius R on its top outward corner and another radius R on its bottom outward corner. Radius R on bead 18 is approximately 5 /64 in. in the preferred embodiment which is selected for illustration, however the invention is not limited thereto. Radius R is relatively small to permit effective sealing of closure 10 to container 14 at this location as will hereinafter be discussed. Radius R functions to accept a pilferproof band 20 at the bottom of closure and the dimensions of radius R are not critical and may vary as is obvious to one skilled in the art.

Closure 10 is comprised of a top end wall 22 and a depending peripheral skirt 26 and may have a knurled band 24 formed therein on the corner between said top end wall and skirt to facilitate gripping of the closure to remove or reapply it. Said depending skirt 26 extends downwardly from top end wall 22 and may have an inwardly directed circumferential rib 27 formed therein adjacent top end wall 22, said rib 27 functioning to retain a sealing composite liner 28 against undersurface 30 of the top end wall.

Sealing liner 28 which has been selected for illustration comprises a composite of materials which are particularly adapted for sealing intravenous solution. It will be apparent, however, that other sealing means known in the art may also be used in a closure of the invention for sealing containers. Composite sealing liner 28 may comprise a bottom layer of gilsonite 32, an intermediate layer of rubber 34, a flanged metal disc 36, and a top layer of high density polyethylene synthetic fiber 38 such as marlex facing top end wall 22 of the closure. Metal disc 36 is especially designed to restrain rubber layer 34 around its periphery so that the rubber cannot extrude outwardly when top sealing pressure is applied against closure 10. Variations in the composition, application and arrangement of the sealing liner may be made such as coating inner surface 30 of the top end wall with a uniform sealing material or providing a disc of polyvinyl chloride or other like material thereagainst as is commonly known in the container industry.

Depending peripheral skirt 26 of closure 10 includes a substantially vertical top portion to be deformed against closure retaining means on a container mouth, an outwardly extending shoulder or sealing land 40 and a lower band portion 20 projecting downwardly from the outer edge of the sealing land. As illustrated, a rounded corner 58 may be provided in closure skirt 26 between its upper portion and sealing land 40, and a second rounded corner 60 may be provided between the sealing land and band 20. The dimensions of

such radii

58 and 60 are not being considered material to the invention.

It is a feature of this invention that sealing material 44 is provided on the inner surface of closure skirt 26 around its entire circumference in corner 60 between sealing land 40 and lower portion 20 of the skirt so that it will contact top radius R, of container bead 18 when closure 10 is secured to container 14 as hereinafter described. An example of such sealing material 44 is plastisol which may be coated onto the inner surface of closure skirt 26 in corner 60 of sealing land 40. Flowable plastisol may be deposited in the corner 60 of sealing land 40 with a machine conventionally used in the closure-container industry and the coated closure may then be heated to cure the plastisol in place. As cured, the plastisol will preferably be adhered to closure skirt 26 so that compressible liner 44 will not fall out of do sure 10 during handling. Plastisol is used by way of example, it being apparent that other materials may also be disposed in the skirt 26 such as for example rubber O-rings or polyvinex chloride gaskets, among others.

Band portion 20 of skirt 26 extends downwardly from the corner 60 of sealing land 40 and is adapted to have at least a bottom edge thereof formed under outwardly projecting bead 18 on container 14, and may have a line of weakening 46 such as a line of slits and bridges located circumferentially therearound separating a locking band on the bottom of the closure from the remainder of the closure. The bridges in the closure skirt are designed to rupture upon closure removal to leave the locking band on container 14. Such a locking band is commonly referred to as a pilferproof band since it provides evidence that a container-closure combination has been opened or pilfered.

The aforementioned description of a closure with a locking or pilferproof band thereon is a preferred embodiment of the invention, it being recognized that there are other means of making a closure pilferproof. For example, a closure of the invention may have a line of slits and bridges therearound separating a locking band on the bottom of the closure from the reaminder of the closure, and also may have a plurality of vertical lines of weakening such as scores in the locking band which rupture on removal of the closure from a container to divide the band into segments between the ruptured vertical lines. On removal of such a closure from a container, the segments may bend on the line of bridges and be flared outwardly by the camming action of the locking shoulder of the container. The segments remain attached to the closure skirt and are removed with the closure. A closure of the invention may also have only a plurality of vertical score lines in the lower portion of the closure skirt which is adapted to be turned under a locking shoulder on a container to form a locking effect therewith, and includes no circumferential line of slits and bridges. When such a closure is removed from a container, the vertical score lines rupture to divide the bottom portion of the closure skirt into segments between the ruptured scores. These segments may be flared outwardly by the camming action of the locking shoulder on a container to permit removal of the closure with the segments attached thereto.

FIG. 2 illustrates closure 10 in the first step of securing the closure to container entrance mouth 12. Closure 10 is positioned over container entrance mouth 12 and downward pressure of approximately 200-700 pounds, and preferably about 300 pounds, is applied to closure 10 with pressure block 50 or the like attached to a standard capping machine (not shown). The top portion of depending peripheral skirt 26 is then deformed against inclined closure retaining means 16 on container 14 by means of rollers 52 while the top pressure is maintained on closure 10 with pressure block 50. To effect this deformation, rollers 52 are moved against and around closure skirt 26 to reform it permanently against container retaining means 16 and thereby form threads in closure skirt 26. The top pressure initially seals closure 10 at container entrance mouth 12 and deformation of closure skirt 26 against inclined retaining means 16 holds closure 10 on container 14 in addition to holding top sealing liner 28 against closure 10 and container entrance mouth 12 thereby providing container14 with a high integrity top seal. Alternatively, it is also believed to be possible to secure a closure having threads embossed therein on a container by turning such a closure onto the container without the application of any external pressure other than the closure itself as it turns onto container.

According to the present invention, a second capping machine (not shown) next seals closure 10 against container 14 to provide a lower seal outwardly of the closure retaining means as illustrated in FIG. 3. Downward pressure is applied against sealing land 40 with a collar or bushing 54 which preferably has a tapered throat therein to direct a substantially downward pressure against the land 40 and the rounder corner R of container bead 18. Application of the substantially downward pressure against closure at sealing land 40 compresses sealing liner 44 against the relatively small top radius R of container bead 18 to form a seal therebetween. Pressures of approximately 300 pounds have been found to work well for such purposes, although it is believed that pressures in the range of 100500 pounds may be used.

FIG. 4 illustrates the final step of securing closure to container 14 wherein a bottom portion of band is tucked under container bead 18 with a forming tool 56 while collar 54 maintains substantially downward pres sure against sealing land of closure 10. After band 20 has been tucked under bead 18 at radius R the pressure of collar 54 against land 40 is released, and the inwardly turned edge of closure 10 against container bead 18 holds the bottom portion of the closure in a restrained condition with sealing material-compressed against an upper surface of container bead 18.

From the above description, it should now be apparent that the present invention provides a tight compression seal at the interface of closure sealing land 40 and container bead 18 as shown in FIG. 5. Sealing material 44 is maintained in compression by the downward restraint provided by the bottom portion of band 20 once this portion is tucked under container bead 18 at corner R Though some previously known closures are sealed against containers at this relative location today, the prior art closures have relied upon sealing pressures produced by an interference fit of the seal against the container and have not been sealed with the assistance of an external force which compresses the seal against the container and such compressed seal thereafter being maintained by the rolled edge of pilferproof band on the closure. The previously known seals therefore could have their integrity violated when the container and its attendant contents are exposed to relatively high internal or external pressures such as are produced during autoclaving of a sealed container. With the present invention, however, high pressures developed during sterilization in autoclave apparatus will not violate the seal outwardly of the closure retaining means since this sea] is maintained under compression by the rolled edge of the closure under the container head. The lower seal in the present invention is substantially impervious to all contaminants, be they solid, liquid or gaseous, both at room temperature and pressure and elevated temperatures and'pressure normally used to sterilize medical supplied in an autoclave because the lower seal is positively compressed against and partially around the container bead relatively small radius. This is a substantial improvement over prior closures which did not include compression of a seal outwardly of the closure retaining means.

Removal of closure 10 from container 14 may be effected by turning closure 10 relative to container 14. Since the lower edge of pilferproof band 20 is turned under container bead 18 and the band has no vertical weakening in the closure selected for illustration, the band cannot be removed from the container. Instead, pilferproof band 20 separates from the remainder of closure 10 at the parting line around its circumference formed by breaking of bridges 48. Pilferproof band 20 remains on container 14 after closure 10 is completely removed. However, in some of the previously described alternative forms of a closure of the invention which include vertical scores in the locking band portion of the closure, the vertical scores are intended to be ruptured upon removal of the closure to divide the band into segments which are removed with the closure.

Closure 10 may be re-secured to container 14 by screwing it onto container 14. When closure 10 is resecured on container 14, a seal is made both at the container entrance mouth 12 and container bead 18, although the seal at container bead 18 is not held under compression as it was prior to initial opening. This is not important, however, since the container-closure combination will not normally be subjected to autoclaving or high pressure differentials subsequent to initial opening thereof. Pilferproof band 20 is separate from closure 10 such that visual inspection of package will reveal that the closure-container combination has been previously opened.

It is therefore seen that an improved closure and a method of applying the same to a container have been illustrated and described in which a seal is provided outwardly of the container retaining means on the container to prevent ingress of contaminants into the space between closure skirt and container finish. By preventing contaminants from entering this area, the closure retaining means on the container is maintained in a sterile condition and will not contaminate the containers contents when emptied from the container.

Whereas a preferred embodiment of the invention has been illustrated and described, it will be apparent to those skilled in the art that numerous variations can be made therein without departing from the scope of the appended claims.

What is claimed is:

l. A method of sealing a closure on a container comprising in sequence the steps of providing a container having an entrance mouth with closure retaining means thereon and an outwardly projecting circumferential bead below said retaining means, positioning a closure on the entrance mouth, said closure having a top end wall, a depending peripheral skirt extending therefrom including an upper portion, a land directed outwardly from the bottom of the upper portion and a band depending from an outer edge of the land, said closure further having a sealing material disposed therein overlying the upper surface of said container bead,

forming said closure skirt against said retaining means on the container mouth,

applying substantially downward pressure against said closure skirt overlying the container bead to press the sealing material against the container bead, and

turning at least a portion of the band on the closure skirt under said container bead to hold the sealing material in the closure skirt pressed against the container bead.

2. A method of sealing a closure on a container according to claim 1 wherein 7 8 said closure is provided with sealing material therein upper seal between the container and closure.

adjacent the container entrance mouth above the 3. A method of sealing a closure on a container acclosure retaining means and cording to claim 1 wherein a pressure in the range of substantially downward pressure is applied against 300-500 pounds is applied against the closure land said top end wall prior to, and during, deformation overlying the container bead to press the sealing mateof said closure depending skirt against said retainrial thereagainst.

ing means on the container mouth to provide an

Claims

1. A method of sealing a closure on a container comprising in sequence the steps of providing a container having an entrance mouth with closure retaining means thereon and an outwardly projecting circumferential bead below said retaining means, positioning a closure on the entrance mouth, said closure having a top end wall, a depending peripheral skirt extending therefrom including an upper portion, a land directed outwardly from the bottom of the upper portion and a band depending from an outer edge of the land, said closure further having a sealing material disposed therein overlying the upper surface of said container bead, forming said closure skirt against said retaining means on the container mouth, applying substantially downward pressure against said closure skirt overlying the container bead to press the sealing material against the container bead, and turning at least a portion of the band on the closure skirt under said container bead to hold the sealing material in the closure skirt pressed against the container bead.

2. A method of sealing a closure on a container according to claim 1 wherein said closure is provided with sealing material therein adjacent the container entrance mouth above the closure retaining means and substantially downward pressure is applied against said top end wall prior to, and during, deformation of said closure depending skirt against said retaining means on the container mouth to provide an upper seal between the container and closure.

3. A method of sealing a closure on a container according to claim 1 wherein a pressure in the range of 300-500 pounds is applied against the closure land overlying the container bead to press the sealing material thereagainst.