US2261117A - Closure member and method of preparing same - Google Patents

Description

Nov. 4, 1941. G. B. JACK, JR

CLOSURE MEMBER AND METHOD OF PREPARING SAME Filed June 9, 1939 |N VENTOR fiw iefirm/mf f:

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ATTORNEY or cement must be used.

Patented Nov. 4, 1941 CLOSURE MEMBER AND METHOD PREPARING SAME George Brinton Jack, Jr.,,South salem, N. Y., assignor to United States Can Corporation, Brooklyn, N. Y., a corporation of New York Application June 9, 1939, SeriaLNo. 278,258

2 Claims. (01. 220-27) 'This invention relates to improvements in clos- :sure members, and method of making the same, :and more particularly to prescored and preformed closure tabs formed in and integral with closure members, of metal, plastics, laminated materials, iand the like, as well as to novel means of sealing the same.

In the packaging of solid, liquid, and pasty materials, including foodstuffs and beverages, a variety of conditions must be taken care of, Conjtainers of glass, metal, cardboard, plastic mate'- rials, laminated fabrics, and the like, have particular advantages for use under different conditions. A major feature of difficulty in packaged foodstufis and beverages is the usual requirement of a special utensil for opening the packages. For example, metal closure members require special cutting instruments or auxiliary opening devices, which either become detached and lost, or are readily misplaced, or, under certain conditions of use, may give rise to painful cuts. With cardboard, fibre and plastic-impregnated paper and fabric containers, the use of metal closures ofiers the same disadvantages. In the case of containers for beverages, and particularly for carbonated beverages, including pop, beer, ales, and the like, the use of pressure proof and gas tight closures is absolutely necessary, yet there is a crying need for closure members which can be manually or digitally operated as conditions determine.

It has been proposed to avoid these conditions byproviding closure members for containers, which closure members including integral tabs or tongues adapted to be manually or digitally depressed or displaced to permit access to the contents, closures are usually integral therewith and are struck-out therefrom. The edges of the tabs and the closure from which they are struck-out-are in substantially abutting relation, requiring the use of special cementing materials or overlays to provide the necessary seal. Where containers maintain materials under pressure, such as-beer or other carbonated beverages, a shearing or elongating effect is maintained along the line of the scoring, and any suflicient bulk of overlay material requisite for maintaining the tab unrup 'tured under pressure, introduces a prohibitive cost element into an already highly competitive cost situation. Further, appreciable amounts of overlay materials tend to prevent the opening of such members by the fingers. It will thus be :seen that minimal amounts of overlay materials Such tongues or tab sections in the.

It has now been found thatdisplaceable tabs or struck-out tongues forclosure. members of metal, thermo-responsive plastic materials, and the like, may be rendered liquid and pressure proof byproviding seats or nesting shoulders for the tabs, and under conditions such that the shoulders or seats provide a proper and suitable support and bearing surface, The providing of a shoulder of substantial extent and a cooperating tongue edge adapted to mate with and nest in the shoulder assures a structurally eflicient support forthe tongue and a bearing surface which will take care of expansion and contraction of the cover material under extremes of heat or cold. In addition, such bearing surface provides a pressure-resisting shoulder for the assembly and ag'ainst-which the closure tab or tongue is maintained under pressure by the gas in a container, or the atmosphere in the case of vacuum containers, it being understood, that in the latter casefthe usual position of the tongue or tab will be reversed. Theseal thus established can be made truly pressure tight by applying a cementing overlay of plastic material, either as such or in the form of coated or surfaced papers fabrics, and the like. Metallic solders may be used in relatively thin films, or both the plastic materials or solders may be preliminarily coated on the surfaces to be joined, and fused or joined .together under pressure and heat during the sealing operation. In any and all events the materials used are chosen with the view to maintaining a proper seal while permitting the rupture of the same by suitable pressure.

With these and Other desirable objects and advantages in mind, the invention comprehends 'the' treatment of metal closure members or thermally-responsive plastic materials, alone or associated with suitable supports, to form novel closures. In the formation of the novel closures of the present. invention, a closure member,

usually in the, form of ,a panel or disc of appropriate size, andhaving edge sections adapted to be crimped on and over a container,- are made use of. These closures are subjected to mechanical treatments to form tongue or tab sections which are displaceable in a portion thereof while tionsof the closure member.

' remaining attached to or integral with the main body of the closure. This is accomplished by stretching or raising the material 'Whichis to "form the tab, whether of metal or plastic,;and

in providing a seat portion in the adjacent sec- Thereafter the edges of the tab'or I tongue are severed, as by cutting with a die, and-thestretched-out marender the same more readily workable. capitulate, the overlay material mayhave a low .melting metal surface or a finish of an of the terial of the so-formed tab is then forced back into its original flat condition with the overhanging or excess material produced by the doming or cupping or expanding of the tab member being forced outwardly into nesting, mating engagement in the shoulder formed in the main body of the closure member. By providing an excess of edge material in the tab or tongue, positive seating of such member in the shouldered body of the closure is assured, and, under suitable conditions of heat and pressure the mating, abutting sections may be sealed by interfusionv of the abutting surfaces. As has been intimated above, the surfacing materials may be thermo-plastic and thus fiowable under heat and pressure. Separate cementing overlays or discs of'plastics, including solders, may be applied over the surfaces of the closure member, or, if desired, over the edges of the displaceable tab sections. Thetabs are thus sealed off from atmospheric influences and the closures rendered pressure proof by their own structural organization, in combination with the applied overlay material. While the term overlay has been used, it will be understood to include Junderlays or any surfacing whatsoever when applied for the sealing purposes of the present invention. In the case of metal materials terne plate may be used as well as any metal surfaced with a low melting metallicsurfacing, or withany plastic surfacing, as well as natural and synthetic gums, waxes, resins, and mixtures of the same, alone, or insuitable solvent media, or containing merely sufficient solvent matter to To rewell-known plastics available, including the vinylite resins alone, r in various combinations, with other resinous materials, or in suitable solvents and in any degree of viscosity. Other materials which may be used include the well-known phenol-formaldehyde, urea-formaldehyde products, alkyd resins, acrylic acid polymerization and condensation products, and other like materials. These synthetic resins, as well as synthetic waxes, together with natural resins and natural waxes, alone, or in combination, and in any suitableform, such as varnishes, enamels, or filmed materials, coated papers, fabrics, and the like, can be used, and abutting surfaces can be joined by hot fusion or under the influence of solvents to secure a continuous seal. I

The closure members prepared according to the present invention will be surfaced with materials which are known to have no efiect on the product to be packaged, and therefore, will not impart bad taste or flavors to such products. In the choice of such materials a Wide latitude is offered as solid materials, such as cereals, and non-liquid materials, other than salt, and saline chemicals, will have sub'stantially'no solvent action on any coating material. Liquids,'including meat juices, soups, and sea-food juices, will introduce problems of their own, and will necessitate the using of materials which are insoluble. This is likewise true of beverages, including beer, which is particularly susceptible to loss of flavor if exposed to surfaces capable of reacting with any of its constituents.

, As indicated above, the structural organization comprehended in the present invention, involvesthe stretching of at least the edge material of the tab, whether metal or plastic, as by doming or. expanding, and the subsequent fiattening out of .such stretched, domed sectionsto rial, as described above.

overlay the adjacent material of the closure member. To improve the mechanical organization of such closure assembly, the overlay section of the tongue or tab member desirably fits, in a mating fit, into a depressed shoulder in the periphery of the opening of the closure, which shoulder provides a substantially precision seat for the periphery of the tab or tongue, and also assures positive maintenance of the periphery of the tongue in supported condition while permitting mutual expansion and contraction of the abutted and mated parts. In this connection it will be noted that any and all sealing materials will be chosen for use with the knowledge that the co-efiicient of expansion of the same will substantially coincide, within operating limits, with the co-eificient of expansion of the materials forming the operating parts of the closure members.

The doming and shouldering operations and mating of the periphery of the tongue or tab with the shoulder section of the closure may, and, preferably will, be done'with dies, and under conditions such that the closure contains a displaceable tab nesting in the body thereof and mechanically supported thereby against outwardly or inwardly exerted gas and atmospheric pressures, and further rendered gas and liquid proof by the presence of suitable overlay mate- While various natural and synthetic resinous materials, including waxes, enamels and varnishes, alone, 0r supported by or impregnated in supporting members, including textiles, cellulose ester films and the like, are adapted for use as pressure and liquid proof overlays'and sealing members. It is also to be understood that various low-melting metals or solders, may be used, as described above, without departing from the spirit and scope of the invention.

The improvements of the present invention .may best be understood by reference to the accompanying drawing, in which:

Fig. 1 is a top plan view, partly broken, of a completed closure member;

Fig. 2 is a vertical section taken on line 2-'-2 of Fig. -1, showing the closure member associated with the container;

Fig. 3 is a top plan view of an enlarged section of a closure showing the initial doming or expansion of the tab section;

Fig. 4 is a transverse section taken on line 4-4 of Fig. 3 and showing the stretching of the domed section, the view being shown inverted;

Fig. 5 is a view similar to Fig. 4 and showing the tab or closure flattened out .and seated in the cover, and a sealing material applied to the edges of the tab;

Fig. fi is asection taken on line 6-6 of 'Fig. 1 and is similar to the showing of Fig. 5 in inverse relation thereto;

Figs. 7, 8, and 9 are views similar to Fig. 6, andshowing modified forms of closure tabs or tongues;

Fig. 10is a top plan view of a closure member similar to Fig. 1 and showing a self-closing tab having an integral rib or spring section therein; Fig. 11 is a vertical section taken on line I l-ll of Fig. 10; and

Fig. 12 is a view similar to Fig. 11, and showing the ribbed tongue depressed to providean a closure IIl having'a rolled, "crimped edge "II applied on 'andove'r a Container 20 havinga mating crimp'ed edge 2 I, rolled under and secured to'and by the edge I I of the cover in'sealing engagement. glass, coated or impregnated paper, fabrics and the like, all as described hereinabove. In the case of glass containers suitable ribs or annuli will replace the turned over edges 2|. The closures I include the edge securing section II in which is disposed a sealingring or gasket 12. An inner ring or stiffening section I3 is formed on the cover adjacent the rim and serves to stiffen and support the member. The depressible tongue or tab I5 has an edge or periphery I6 fitting, in mating engagement, and seated in shoulder I! of the cover. The tab or tongue I5 may have an extension or tip I8 mating with a conformed section I9 of the cover. A sealing overlay 30 of plastic impregnated or surfaced paper, fabric or other material may be applied over the inner surface of the cover and secured in place as by crimping, as indicated at ill, see Fig. 2, although it will be understood that material may be secured to the cover by the conjoint action of heat and pressure. Where desired, sealing material may form an annulus, as indicated at 32 in Figs. 5, 6, and 9.

In forming the closure tongues of the cover, and with particular reference to Figs. 3, 4 and 5, the metal of the tab section I5 is first expanded or domed and stretched, as indicated at I5a, and in an area sharply outlined by a peripheral margin I6a, which defines the shape of the finished opening. The hinged section I52) remains substantially unaltered and provides a desirable stiffening support for the tabs. After the domed or expanded section I5a is formed, it is slotted around the line indicated at H511, and the stretched metal of IE4: is flattened down to form tab I5 whose periphery I6 fits in a sliding, mating engagement on the conformed shoulder I I, which has been simultaneously formed on the body of the closure. It will be seen that with such a mechanical arrangement, the shoulder I'I provides a broad, continuous seating surface for the periphery I6 of the displaceable tongue I5, and any pressure exerted against the under surface of tab I5 will seat it firmly against shoulder I I. Where the surfaces of shoulder I! and peripheral edge I6 are coated with metallic or plastic materials, mutually fusible under heat and pressure, a perfect gas tight joint is assured. Separate overlays 3|] of coated fabric or paper or annuli or cementing rings 32 may be used to insure the desired pressure-resistant seal. While the description and drawing illustrate the use of the invention with respect to containers adapted to contain materials under pressure, it will be understood, that in the case of vacuum-packaged materials, such as certain cereals, tobacco, and other like materials, the displaceable closure members will be arranged to open outwardly of the container and for this purpose may be provided with rings or pull members to facilitate the opening of the same.

It is to be noted that although the displaceable cover section has been illustrated as opening inwardly of the cover in Figs. 1, 5, and 6, it can be reversed so as to have the opening adjacent the rim of the cover, as illustrated in Figs. 10, 11 and 12. It will be noted further, with reference to these figures, the tab may cover an appreciable portion of the cover, as indicated at I50. With further reference to Figs. 10, 11 and 12, the dis- The container 20 may be of metal,

placeable closure I50 can be made self closingby providing a rib I9 integral therewith and extend ing into and forming a part of the unscored sectionof the cover. This rib or blister. I Sthus serves as an added stiffening for the tab I50, as well as serving as a spring member to restore to its seated position in the cover when'its displacing pressure is released. The containers with such a closure in the cover may be used for condiments, cereals, and other dry or liquidmaterials which are to be maintained and kept in the container. The segment of rib or blister I91 which is struck-out from the cover proper provides a bridging and cantilever section imparting the spring'urge' to'the tab or tongue I50, and maintaining the latter in its normal, seated, closed position.

Referring now to Figs. 7, 8 and 9, there are shown modified closure tabs 40, 50 and 60. Tab 40 is provided with a beaded edge II mating with a conformed shoulder or sleeve IIa in the closure member. In Fig. 8 the tab is provided with a quadrantal bead 5I nesting in mated, seated engagement with conformed shoulder III). In Fig. 9 a dished closure 60 having substantially vertical edges 6I fits in mating engagement with rectilinear shoulder IIc of the cover. An annulus 32 of sealing material may be applied, as illustrated. In every instance suitable sealing material may be incorporated as noted hereinabove.

It will now be appreciated that there has been provided novel closure members having manually or digitally depressible tongues or tabs with associated sealing materials rendering the same gas and liquid tight in association with the novel mechanical organization of the displaceable tab of the closure member. Such closure members have been shown to be particularly suited for use in packages or containers for marketing a variety of discrete solid, liquid and pasty materials, including foodstuffs, beverages, and other classes of merchandise.

What is claimed is:

1. A container cap adapted to close and hermetically seal a container, said cap being of relatively thin material and substantially flat at its upper and lower surfaces within its peripheral portion and provided in such fiat portion with a cut extending entirely through the material to provide a depressible tab having hinged connection at one side with the cap, said cap being indented at its fiat inner surface and interiorly grooved thereby in parallelism with the free edge of the depressible tab and forming a shoulder conforming to the configuration of the adjacent edge of the tab and providing an interior recess for said free edge, the tab being flattened and expanded and having its free marginal portion extending into said recess and into abutting engagement with said shoulder and lying within substantially the plane of the body portion of the cap, the wall of the recess providing an overhanging flange for the marginal portion of the tab and arranged to resist internal pressure and forming an exterior shield for the free edge of the tab, and a film of frangible sealing material overlying and covering the seam existing between the shoulder and free edges on the side of the cap inwardly of the container for sealing the edges of the tab and the shoulder together.

2. A container cap adapted to close and hermetically seal a container, said cap being of relatively thin material and substantially flat at its upper and lower surfaces within its peripheral portion and provided in such flat portion mth a cut extending entirely through the material to provide a depressible tab having hinged connection at one side with the cap, said cap being indented at its fiat inner surface and interiorly grooved thereby in parallelism with the free edge of the depressible tab and forming a shoulder conforming to the configuration of the adjacent edge of the tab and providing an interior recess for said free edge, the tab being flattened and expanded and having its free marginal portion extending into said recess and into abutting engagement with said shoulder and lying within substantially the plane of the body portion of the cap, the wall of the recess providing an overhanging flange for the marginal portion of the tab and arranged to resist internal pressure and forming an exterior shield for the free edge of the tab, said cap having a rib extending completely across the hinge connection and intersecting the axis thereof to stiffen the same and provide for a spring action of the tab to restore the latter to its seated position in the cap with relation to said shoulder upon release of digital pressure, and a film of frangible sealing material overlying and covering the seam existing between the shoulder and free edges on the side of the cap inwardly of the container for sealing the edges of the tab and the shoulder together.

GEORGE BRINTON JACK, JR.

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