US2409789A - Method of sealing containers - Google Patents

Description

Oct. Z2,v 1946. A. G. OSBORNE 2,409,789

v METHOD OF SEALING CONTAINERS Filed Sept. 21, 1945 N NTQ BYv I ATTO R N Y Patented Oct 22, 1946 Tsb "PATENT o 2,409,789- -Mir]?i161) 6FsEALnITG ooiwr'AiN'nRs Andrew' Osborne, NewKensington, Pa as- Sig 1 .to Aluminum (309 1 391X, 9f. r Americ Pittsburgh, Pa., a corporation of Pennsylvania Aiiiiiiandfs tiilbr 21, E43, serial No. 503,185

{This invention ie'lates tdthe*sealing of containers'and moreparticularlyto"a method of iip yingjcicsui es'w containers.

Infclosures" for" containers, the sealing "action is accomplished "by pressing' the sealingfriiaterial against" one or'inore sealing surfaces of the container finish within the closure. "Co'r'n'pressible or practicallydeformable materials, enemas coil; or soft riibberf'areof' cdurse de'sirable for thispurpose but because "thse"materials are not always readily available or are relatively expensive, the use"ofeheaper"and less compressiblernaterials, siich aspaperypulpboard, orthe like, becomes a 'pra tical neces ity. "These relatively incompressible materials must be held by"anunyielding force in intimate contact with the sealing surface of the container "to' insure tight, positive'sealing. When the pressurefholding the liners of these materials inl'se'aling' engagement is reneved; these liners,"becaus'e'ftlieir slightcompr'es'sibility is permanent; lose their sealingfefliciency; therefore, in the "fise 'bf these"materials as liners every 'ffo'rt'is made tdprei ent any" diminution of the -pressurel'idlding the liners in sealing engage- "rn'ent, This; prbb lemtis' not particularly "serious in "connection "withkcrewftype closures because the 'press'ureds progressively increased in the sealing operation by screwing the closure onto the container, and consequently there is hooppdrtunity for spring back. However, considerable 'diflicultyis'sometimes encountered in the use of "these runway;in em ressiue materials in closuresofthe'shap entype or in closures secured to'the'" container bythe reformation of the 'clos'ureskirt in whichthe securing meansmay yield jsliglitly whenfthe"pressure of 'the sealing apparatus is removed.

For convenience of description, sealing materials suchas paper, cardboard, pulpboard and the'like'may hereinafter be referred to as incompressiblrnaterials even thoug'h'they are slightly but 'perm'anently compressible. As employed throughout this specification and appended claims, container finish refers to the portion ofthe container embraced by the closure, and sealing surface refers to'that portion'of the container'finish contacted by the liner.

The present invention contemplates the formation of a top and side seal between the container finish and a liner'of incompressible "material wherein the liner is reformed around the outside of the container mouth, thereby producing a hermetic seal within broad lifnitsiiof tolerance for any particular-I glass container ifinish, The present invention also contemplates the formaa 6 oiaiiiis. mura s) tion of the aforementioned "top and side 'seal in combination with anymethod involving'the application "of direct downward'pressure to the top of the closure without subjecting the closure to any" turning or screwingunovement.

It is'an'object of the present invention to pro- .Vide' amethodi'ofj forming'a hermetic 'sealrbetween the. container finish andplosure liners'of paper, pulpboard, and other similar incompressible 'materi'a'ls. Anbther object of the 'p'resentinven- 'tion isto' provide themethod of applying closures to containers wherein the liner is reformed 'to" a plurality of "sealing surfaces on the"container finish. Another object isto' provide "a method of "applying closures to' 'cont'ainers wherein "'a closure liner of "incompressible material is "re- 'formedinto' and retained in" sealing engagement with the top and'sides of the "contaiherfinish. Further objects and advantages will be apparent from the folldwing'descriptien ofmy method and of "the specific" embodiment thereof.

Y In the" accompanying drawing:

Fig. 1" isanjjeIevati n of a closure blahk and a 'c'o'ntainer'tq which theblanl; is"to"beapplied, a portion of the blank being shown in section, and

a' pressure block for forcing the closure into seal- 1 ing" relationship being "shown in' positibn' above "the blank;

Fig: is a aptat on-qr acidntainienanda partial sectionof aclosure' after 'the blank of Fig; 1

in rigsis and 4.

According to my invention," a hermetic "seal is produced between the container sealing surface and a liner of incompressible sealing material by reforming the marginal area of the liner into intimate contact" with the 'top'f andsides of the container finishby the application" of direct downward pressure and there retaining the liner by" superposing a portion of the skirt on [the re- Tormedmarginal area of the liner. *Thisp'ortion of the skirt, and consequently the marginal area of the liner, are held, securely in" sealing'relationship tothe' container bya'suitable closure'securing means disposedon the lower portion 'ofthe closure skirt. In practicingthe present invention, the applicant employs a closure blank consisting of a top portion which, is preferably flat or only slightly convex, a depending skirt, an annular shoulder or annular bulge defining a channel opening inwardly in the skirt in spaced relationship to the top portion, and a liner disc or ring seated in the channel or against the annular shoulder and there preferably held by some suitable skirt construction. Before the blank is applied to the container, the liner is a fiat disc or ring of a diameter somewhat larger than the outside diameter of the sealing surface of the container finish to provide sufficient material to form a side seal as well as a top seal and to allow sufiicient marginal area for meeting the maximum limits of tolerance in the container finish.

During the sealing operation the aforementioned blank is placed loosely over a container mouth, and the two are then moved relative to a sealing head having a pressure block the contact end of which has substantially the same contour as the upper portion of the blank. When the loosely applied blank and the pressure block are brought into engagement, sufficient pressure is applied axially to the blank to cause the shoulder or upper wall of the channel of the blank to reform the marginal area of the liner downwardly around the sides of the container finish. This operation also draws or presses the liner into intimate contact with the top sealing surface of the container finish. As the liner is drawn around the sides of the container by the shoulder or bulge, a portion of the skirt above the shoulder or bulge slips over the deformed liner and securely retains the margin thereof in intimate contact with the sides of the container finish. The portion of the skirt above the shoulder or bulge is of a diameter small enough in relation to the total diameter of the container finish and double thickness of the deformed marginal area of the liner to press and hold this marginal area against the side sealing surface. When the foregoing operation has been completed, the closure is secured to the container by any satisfactory means, as for example, by reforming the lower portion of the skirt to a threaded configuration n the container. The closure may be secured to the container by the lug and bead arrangement of a snap-on type closure. In this type of closure the lugs and bead come into engagement during the liner deformation step. During the operation in which the liner is being deformed around the outside of the container mouth any turning or screwing movement of the blank is to be avoided since such movement at that time tends to displace the liner and produce a defective seal.

Referring now to the drawing, wherein two embodiments of my invention are illustrated, the blank of Fig. 1 consisting of a flat top I, plain skirt 2, bead 3 for reinforcing the lower margin thereof, an annular bulge 4, and a flat liner 5 seated in the channel defined by the bulge, is shown resting on the mouth of container 6 preparatory to being pressed into sealing relationship by pressure block B, shown in position over the blank. Before the blank is pressed into sealing relationship with the container, the oversize liner 5 rests snugly in the channel within annular bulge 4 of skirt 2 and is thereby prevented from becoming dislodged from, or displaced in, the blank before the application of the blank to the container.

The pressure block B may form an element in a bottle capping apparatus such as that disclosed in U. S. Patent 1,674,266 to Sharp. The substitution of my pressure block for the one shown in the Sharp patent does not change the mode of operation of that apparatus. With the snap-on type closure, the pressure block may perform the entire operation of pressing the liner into sealing relationship and securing the closure to the container or it may operate in cooperation with a member which forms the lugs in the closure skirt during the sealing operation.

In the sealing operation, container 6, with the closure blank in position over the mouth thereof as shown in Fig. l, and pressure block B, which is designed to conform to the contour of the preformed upper portion of the blank engaged thereby, are moved relative to one another. The pressure applied to top I and annular bulge 4 causes the upper wall of the channel constituting a shoulder 1 to bear against the margin 8 of liner 5 and to reform the margin around the outside of the container finish. The constricted portion 9 of the skirt slips over the reformed margin, further pressing the liner against the side of the container finish and drawing the flat portion of the liner into intimate contact with the top sealing surface. 9 restrains the margin 8 of the liner in the deformed shape and retains it against the sides of the container finish until the closure is removed from the container.-

As shown in Fig. 2, after the liner has been deformed around the outside of the container mouth and the constricted portion 9 of the skirt has been-pressed over the deformed margin of the liner in the foregoing manner, the closure is secured into sealing relationship with the container by reforming the lower portion of the skirt to the threaded configuration of the container finish or to the annular bead on the container. The construction in which the skirt is reformed to an annular bead is not shown in the drawing; however, it will be appreciated that the present method and blank are readily adaptable to such construction. As shown in Fig. 4, wherein the numerals correspond to those of Figs. 1 and 2, the lugs ll) of the closure have been forced beneath the bead l I of the container. This operation was accomplished during the deformation of the liner from the shape shown in Fig. 3 to that of Fig. 4. In this modification the liner is retained in the closure before application thereof by the lugs, as shown in Fig. 5.

By varying the diameter within the constricted portion, the pressure exerted thereby can be made greatest at the point or points of greatest importance, Consequently the pressure against the constricted portion on the margin of the liner, particularly at a point near the lower edge thereof, can be increased somewhat by reducing the diameter of the constricted portion adjacent the annular shoulder or bulge as shown in Fig. 3.

Throughout the specification the description of my invention has been principally directed to the formation of hermetic seals with closures having liners of pulpboard and similar relatively incompressible materials. Reference to these materials has been made primarily because the invention is particularly adapted to the formation of hermetic seals with these materials but this specific reference is in no way intended as a limitation on my invention, more easily compressible or plastic deformable materials such as cork and rubber being entirely suitable in practicing my invention.

I claim:

1. In the art of sealing containers having a side sealing surface with a blank having a top portion,

The constricted portion J a depending skirt, an inwardly extending annular shoulder in said skirt in spaced relation to said top portion, and a liner of greater diameter than the outside diameter of the mouth of the container to be sealed disposed within said skirt below said shoulder, the steps comprising placing said blank over the mouth of said container, applying a pressure means to said blank axially of the container reforming the margin of said liner around the upper part of the container finish and into sealing engagement with said side sealing surface independently of pressure of said top portion against said liner by pressing said shoulder by direct downward pressure against said margin at least until the shoulder passes below the container mouth.

2. In the art of sealing containers having a side sealing surface with a blank having a top portion, a depending skirt, an'inwardly extending annular shoulder in said skirt in spaced relation to said top portion, an annular constricted portion between said shoulder and said top portion, and a liner of greater diameter than the outside diameter of the mouth of the container to be sealed disposed within the skirt below said shoulder, the steps comprising placing said blank over the mouth of said container, applying a, pressure means to said blank axially of the container reforming the margin of said liner around the top of the container finish and into sealing engagement with said side sealing surface independently of pressure of said top portion against said liner by pressing said shoulder by direct downward pressure against said margin at least until the shoulder passes below the container mouth, slipping said constricted portion over the deformed margin to laterally press and retain said margin in sealing engagement with the container finish, and securing the closure to the container.

3. In the art of sealing containers having a side sealing surface with a blank having a top portion, a depending skirt, an inwardly extending annular shoulder in said skirt in spaced relation to said top portion, an annular constricted portion between said shoulder and said top portion, and a liner of greater diameter than the outside diameter of the mouth of the container to be sealed disposed within the skirt below said shoulder, the steps comprising placing said blank over the mouth of said container, applying a pressure means to said blank axially of the container reforming the margin of said liner around the top of the container finish and into sealing engagement with said side sealing surface independently of pressure of said top portion against said liner by pressing said shoulder by direct downward pressure against said margin at least until the shoulder passes below the container mouth, slipping said constricted portion over the deformed margin to laterally press and retain said margin in sealing engagement with the container finish, and securing the closure to the container by reforming the skirt below said shoulder to the contour of the container finish.

4. In the art of sealing containers having a side sealing surface with a blank having a top portion, a depending skirt, an inwardly disposed annular channel in said skirt in spaced relation to said top portion, and a liner disposed in said channel, the steps comprising placing said blank over the mouth of the container to be sealed, applying a pressure means to said blank axially of the container reforming the margin of said liner around the top of the container finish and into sealing engagement with said side sealing surface independently of pressure of said top portion against said liner by pressing a wall of said channel by direct downward pressure against the margin at least until the channel passes below the container mouth.

5. In the art of sealing containers having a side sealing surface with a blank having a top portion, a depending skirt, an inwardly disposed annular channel in said skirt in spaced relation to said top portion, an annular constricted portion between said channel and said top portion, and a liner disposed with its edge resting in said channel, the steps comprising applying a pressure means axially to said blank reforming the margin of said liner around the top of the finish of the container to be sealed and into sealing engagement with said side sealing surface independently of pressure of said top portion against said liner by pressing the upper wall of said channel by direct downward pressure against the margin at least until the channel passes below the container mouth and reforming the lower portion of the skirt to the container finish.

6. In the art of sealing containers having a side sealing surface with a blank having a top portion, a depending skirt, an inwardly extending annular shoulder in said skirt and a liner of greater diameter than the outside diameter of the mouth of the container to be sealed disposed within the skirt below said shoulder, said shoulder being spaced below said top portion a distance greater than the distance between the top of the container finish and said top portion at the completion of the sealing of the container, the steps comprising applying a pressure means to said blank axially of the container bending the margin of the liner into sealing engagement with said side sealing surface by pressing said shoulder against said margin, and thereafter pressing said top portion against said liner while retaining said margin in sealing engagement with said side sealing surface by means of a portion of said skirt intermediate said shoulder and said top portion.

ANDREW G. OSBORNE.

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