US2051976A - Closure for packing vessels - Google Patents

Description

Aug. 25, 1936. w. P. WHITE CLOSURE FOR PACKING VESSELS Original Filed Dec. 1, 1933 I Patented Aug. 25, 1936 CLOSURE FOR PACKING VESSELS William P. White, Glencoe, Ill., assignor to White Cap Company, Chicago, 111., a corporation of Delaware Original application December 1, 1933, Serial No. 700,417. Divided and this application April 13, 1934. Serial No. 720,365

' 4 Claims.

This invention relates to closure caps for packing vessels, such as tumblers, jars, cans, etc. utilized for the preservative packing or packaging of food or other materials. The present applica- 5 tion is a division of my co-pending application Serial No. 700,417, filed December 1, 1933. With the steadily increasing popularity of glass vessels for the packaging of various food com-- modities, there has arisen a desire for the use of part of packers has arisen, no doubt, in some measure from 'the fact that a thin glass or tumbler is a more acceptable piece of tableware than a thick one and hence more attractive to the consumer, but more particularly from the fact that a great saving in weight, and hence in shipping cost, may be accomplished by use of thin glassware instead of glassware of the thickness and weight heretofore most generally employed.

The use of thin glassware for such packages has presented various problems, one of which has been the difficulty of providing an economical and easily applied closure for such ware. Obviously, the thin 'ware cannot sustain the degree of mechanical pressure incident to the seating and sealing of the closure thereon, that can be safely assumed by the heavier ware. Moreover, the sealing area presented by the rim of a thin glass is very much less than that afforded by the rim of a thick glass. Furthermore, it is not feasible or desirable to provide thin glassware with various types of sealing beads, ledges, shoulders, or other formations, such as have characterized various thick glass vessels which have been used heretofore. Because of these and various other circumstances, it is not commercially feasible to use on thin glassware various types of closures or caps which have found practicaluse on thick glassware. l

A general object of the present invention is the .provision of a closure cap which may be manufactured at low cost and easily applied in commercial packing practice to thin glass vessels to form an hermetically sealed closure therefor.

A more particular object is the provision of such a closure which will accomodate the contemplated tolerance variations in the form and size of thin glassware, and function with the desired-certainty as to forming a secure hermetic seal. 50 Other and further objects will'be pointed out or indicated hereinafter, or will be apparent to one skilled in the art upon an understanding of the invention or its employment in practice.

.For the purpose of aiding in a disclosure and vessels which are quite thin. This desire on the explanation of the invention, I show in the accompanying drawing forming a part of this specification, and hereinafter describe, a closure cap of a certain construction. While this serves to exemplify the invention, it is to be understood 5 that it is'presented entirely by way of illustra-. tion, as the invention may be embodied in various other forms. Accordingly, the particular exempliflcations herein shown and described are not to be accorded any interpretation calculated to 10 limit the appended claims short of the true and most comprehensive scope of the invention in the art.

In said drawing,

Fig. 1 is a sectional elevation of a closure cap 15 embodying the present invention, the section being taken on a diameter thereof;

Fig. 2 is a side elevation of same;

Fig. 3 is a sectional elevation illustrating the same closure cap as applied to a thin glass vessel 20 of upwardly flaring form;

' Fig. 4 is a similar sectional elevation showing the same closure cap as applied to a thin glass vessel of upwardly converging form;

Fig. 5 is a part bottom view of the closure cap; 5

and

Fig. '6 is a sectional elevation showing the closure cap applied to a relatively thick straight walled vessel.

The present invention provides a form of closure cap in which a suitable sealing gasket is securely retained in proper positionv in a suitable shell, such that the gasket will provide an effective hermetic seal between the shell and the mouth rim of the appropriate vessel when the closure is seated thereon. The shell has a depending annular skirt or flange which is adapted to encompass the vessel, and thegasket, which is of a flat ring type, is of substantial width in the radial directions of the cap, extending a substantial distance outwardly beyond the minimuminternal circumference or compass of the skirt, and extending also to a greater distance inwardly therefrom. A closure of this description may be made by providing a cap shell with an annular depending flange, placing a pre-formed annular gasket of more or less plastic material within the shell, pressing the gasket against the top of the shell adjacent the flange, and contracting the lower portion of the flange circumferentially to a size somewhat less than the circumferential size of the gasket. Incident to the compression of the gasket, its circumferential extent may be somewhat increased, and it. also may be caused to adhere to the shell.

The nature of the invention may be ascertained in more detail by consideration of the illustrated embodiment which will now be described.

In the closure 'cap illustrated in the drawing, a suitable shell having a top panel l0 and an annular skirt portion II is formed of sheet metal having suitable ductility and strength, such as tinned steelplate, the internal diameter of the top panel being somewhat greater than the external diameter across the mouth of. the vessel for which the closure'is designed.

The gasket I2 is formed of a plastic sealing material, such as a rubber composition, and, depending on the intended use of the closure, it may be either a rubber composition which is, free of vulcanizing ingredients, or one which is partly vulcanized or contains a proportion oi vulcanizing material less than that requisite for complete vul-, canization of the rubber content. The gasket composition also properly includes a suitable filler or pigment in proper proportion. The lower portion of the shell skirt is reduced to a lesser diameter than its upper portion, such as to permit freely the introduction of the mouth of the vessel within it, and the upper portion preferably is formed with a bulge or bead adjacent its junction with the top panel. The gasket is of flat ring form and is of substantial thickness, but of considerably greater width than thickness. It is of a diameter such that when lying in contact with the under surface of the top panel, its periphery will "contact, or approximately contact, the upper portion of the skirt, its periphery thus lying outwardly beyond the compass of the lower constricted portion of the skirt. The gasket is of such width that its inner edge lies inwardly to a considerably greater distance beyond the mini- I mum compass of the skirt, so that the gasket will extend entirely across the mouth rim of a suitable vessel on which the closure cap is maintained in approximately coaxial position by cooperation of the constricted portion of shell flange with the periphery of the vessel. The gasket is of thickness such as to allow for the penetration of the rim of a thin walled vessel into it to an extent such as to form a seal for a short distancedown the inner and outer sides of the vessel wall as well as completely across its top margin. Preferably the gasket is adherently attached to the top panel. A closure cap of the construction above described may be employed eflectively to provide a closure and hermetic seal on vessels of various different forms, In Fig. 3 the closure cap is shown sealed on a thin glass vessel F having an upwardly flaring mouth wall, in Fig. 4 it is shown sealed on a thin glass vessel T having an upwardly tapering mouth wall, and in Fig. 6 it is shown sealed on a thick glass vessel S having, an approximately cylindrical mouth wall. The closure cap is sealed on the vessel by inserting the mouth of the latter within the compass ofthe shell skirt, then exhausting air from within the vessel, then pressing the closure. downwardly on the vessel so as to cause the mouth rim to penetrate into the gasket for a distance. It is held in placeon the vessel by the external atmospheric pressure which is superior to the pressure effective on the closure cap internally of the package, and the external atmospheric pressure may cause the top panel to take a more or less concave form, as illustrated in Figs. 3, 4, and 6, thereby pressing the inwardly lying portions of the gasket somewhat'outwardly toward the inner wall surface of the vessel. Va.- rious commodities, such as jellies, are packed while quite hot, the vessel becoming heated from vulcanizedrubber, the heat from the vessel rim may cause the gasket material to become somewhat tacky and stick to the vessel, thus aiding in 5 retention of the closure cap on the vessel. Or, heat may be transmitted to the gasket from the pressing device which forces it to sealed position, and adhesion of the gasket and vessel thereby effected.

The lower portion of the shell skirt functions as a guide or gauge to position the closure cap approximately coaxially on the vessel, and because of its being of a diameter less than the periphery of the gasket, it holds the upper portion of the skirt and the outer margin of the gasket outwardly beyond the periphery of the mouth rim of the vessel, prevents the introduction of the vessel rim between the gasket and skirt and makes it certain that there will be suitable area of sealing contact between the gasket and vessel rim gasket width being such that the portion of the gasket material in contact with the vessel rim is well supported .by that located inwardly therefrom, so that a firm sealing contact between the gasket and vessel may be effected by light pressure on the cap. I

It will be appreciated, therefore, that due to the form of the closure, the ease with which it may be applied to a vessel, the liberal tolerances in size and form which the closure accommodates, and the certainty which it afiordsthat all portions of the vessel rim will be surrounded by the .sealing material, the closure possesses distinct advantages and utility, particularly in commercial packing in which rapid operation isdesired. Moreover, due to the fact that but very little force is required for the efiective sealing of the closure on the vessel, it is particularly qualified for use on thin glassware.

The closure cap may be readily'removed from the vessel by puncturing it, to accomplish equalization of the external and internal pressures, and then pushing it upwardly from the vessel.

What I claim is:

1. A closure cap for forming an hermetic seal on the mouth rim of a packing vessel, comprising a shell having a top panel with a continuous annular depending skirt, and a ring gasket of plastic sealing material secured in contact with the top panel with its periphery adjacent the upper portion of the shell skirt, said skirt being pre-formed in such proportions that it converges downwardly below the gasket to a minimum compass substantially smaller than the circumference of the gasket but such as to accommodate introduction of the mouth of the vessel freely, and the gasket being of such width as to extend a substantial distance, inwardly beyond the mouth rim of the vessel when the closure cap is guided by the skirt in approximately coaxial relationship therewith, the lower portion of such skirt cooperating with the peripheral'surface of the vessel to prevent lateral movement of theskirt into contact with the peripheryfiof the vessel 76 mouth rim when the gasket is resting on the mouth rim.

2. A-ciosure cap as specified in claim 1 and wherein the thickness of the gasket is such as to accommodate the instrusion of the mouth rim of a vessel into it to an extent such that it will overlap the inner and outer wall surfaces of the vessel.

3. A closure cap for forming an hermetic seal on the rim of a thin glass vessel, comprising a shell having a top panel and a substantially rigid annular skirt depending from the peripherythereof, said skirt being of downwardly tapering form so that it is of smaller diameter at its lower margin than it is at its upper portion, and a ring gasket of plastic sealing material adherently attached to the under surface of the top panel, said gasket being of substantially greater width than thickness and having its periphery lying outwardly beyond the lower margin of the skirt and its inner margin lying a substantial distance inwardly therefrom, whereby the lower portion of the shell is adapted to accommodate introduction 01' the vessel freely and by engagement with the periphery of the vessel below its mouth position the periphery of the gasket outwardly beyond the periphery of the mouth rim of the vessel and the inner margin of the gasket a substantial distance inwardly from the mouth rim oi the vessel so as to permit intrusion of the mouth rim into the gasket at a distance inwardly from the periphery'thereof and yutwardly from the inner,

margin thereof.

4. Thecombination with a packing vessel having a thin mouth rim, of a closure cap comprising a shell having a top panel and a substantially rigid annular skirt depending therefrom, said skirt being of downwardly tapering form so that its diameter at its lower margin isless than that or its upper portion but is suflicient to accommo date the upper portion of the vessel loosely, and a ring gasket of plastic sealing material adherently attached to the under surface of the top panel with its inner margin lying inwardly from the lower margin of the skirt to a distance substantially greater than the thickness of the mouth rim of the vessel, and its periphery lying outwardly beyond the lower margin of the skirt to a distance such that when the lower portion of the skirt is in contact with the periphery of the vessel at any point the periphery of the gasket will be outwardly beyond the periphery of the mouth rim of the vessel.

WILLIAMP. WHITE.

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