US3110409A

US3110409A - Closure cap for glass containers

Info

Publication number: US3110409A
Application number: US147926A
Authority: US
Inventors: George F Chaplin
Original assignee: Continental Can Co Inc
Current assignee: Continental Can Co Inc
Priority date: 1961-10-26
Filing date: 1961-10-26
Publication date: 1963-11-12
Anticipated expiration: 1980-11-12
Also published as: DE1214562B; OA01141A; GB962607A; NL275632A

Description

Nov. 12, 1963 G. F. CHAPLIN 3,110,409

CLOSURE CAP FOR GLASS CONTAINERS Filed ocr. 2e, 1961 2 sneek-sheet 1 rEN TOR.

Nov. 12, 1963 G. F. cHAPLlN cLosuRE CAP FOR GLASS CONTAINERS 2 Sheets-Sheet 2 Filed OCT.. 26, 1961 The present 'invention is primarily concerned with the particular conformation of the cap shell in the region ol the `corner -orrned in pant by the top panel portion "i and in part by the depending skirt portion 3 together with the special conformation of the gasket lil lodged in place therein. Reference is now made to FIGS. 6 and 7 for a detailed description Iof these features of the closure cap t3. Adjacent Athe outer periphery of the top panel portion 7 and forming the outer margin thereof, the cap shell has a down-turned chan-nel portion indicated generally at l5 in FIGS. 6 and 7 with the inner wall thereof being indicated at 16, the outer wall portion being indicated at 3.7, and with the flat interconnecting portion of the channel being indicated at l. The outer wall portion 17 integrally merges with a downwardly, and outwardly tapered skirt portion 2.6* which at its lower end merges with a reversely 'curved portion of the skirt 2l. The skirt portion 21 which connects with the lower end of the skirt portion Ztl is both outwardly and downwardly ilared and the middle of this double-curved portion 2l constitutes a shoulder intermediate the inner step portion 2% or the skirt and the outer, substantially straight or vertical, portion 22 thereof which carries the bead 1l and lugs l2.

The gasket lll includes a main cushion portion 23 which completely tills the downward channel l5, and a downwardly and outwardly tapered elongated portion L4 which follows `down along the inside of the tapered portion 20 of the cap shell. terminates in an outwardly ilared feather edge portion 25 which actually ends at approximately 26 underneath the shoulder portion of the shell. it will be seen that the upper edge of the gasket lli terminates on the underside yof the top panel portion 7 adjacent the bottom end of the channel forming wall i6, as indicated at 27.

The gasket ltlmay be formed of various known rubber-like resilient gasket materials having the desired physical and chemical properties. A preferred class of materials from which the gaskets lo may be formed are the resin compositions known in the art as plastisols A preferred plastisol type gasket composition is described in detail in Unger :and Zipper Patent No. 2,874,863. The gaskets itl may be deposited in the cap shells by various known techniques, one being the so-called ilowed-in technique wherein the plastisol composition is uncured, paste-like condition is squirted' from one or more nozzles into the cap shells (at position 8 cap shell portion FIG. 5) whichare turned upside down on a chuck rotating at high speed. Due to centrifugal force the gasket material will assume the desired contour und shape. After being thus deposited or flowed-in the gaskets are cured or set by a heating operation according to known procedures and using known equipment. rThe cured gaskets will permanently adhere to the interior `of the shell.

According to another technique the proper amount of gasket material can be deposited in the corner portion and then it can be correctly shaped by a forming die which may also be heated `so as to simultaneously shape and cure the gasket material.

The present invention is not particularly concerned with either the details of the gasket composition or the particular technique used in forming it into the gaskets 1t?. Rather, any suitable rubber-like resilient gasket material having the proper physical and chemical properties may lbe used, and any suitable manufacturing techniques may be employed.

The sealing finish of the glass jar 5 comprises a top edge portion 3G which merges with a :beveled ortapered side seal portion 3l. The relative relationship of the gasket lil, and the glass finish when the closure cap 6 is in'fully sealed position are shown .in FIG. 7. The closure caps d are applied to the iilled glass jars S and turned Y down to fully sealed position thereon in known manner using lnown high speed capping equipment. Generally, this 4combined capping and sealing operation begins with applying the caps loosely onto the mouths of the jars At its lower end, the gasket lo f CIT passing through an atmosphere of steam, and then turning the caps down lightly to position with the lugs 12 engaging underneath the glass lugs l. Then while the jars re restrained from turning, the caps 6 are turned down to their ifull `down and sealing position bringing about the relationship of the gasket and sealing iinish shown in HG. 7. The head space in each of the jars is iilled with `steam during the capping operation so that when this trapped steam condenses after capping, a vacuum is created within the head space which enhances the hermetic seal between the gasket l@ and the glass finish.

Referring to FlG. 7 it will be seen that the top edge of the sealing nish of the glass container has upwardly compressed the gasket material in the cushion area 23 with the result that an inner part of lthe gasket material is bulged inwardly as indicated at 32 in FlG. 7. However, the bulged portion 32 is under compression so that there is no tendency to lift or loosen the seal formed between the `gasket and the interior of the shell in the vicinity of the lower end of the chan-nel wall lo where the gasket edge terminates at 27. At the same time the tapered pontion 2li of the gasket is upwardly ironed or drawn out so as to completely blanket the inclined side sealing area 3l of the glass finish and extend downwardly there beyond to the vertical portion of the glass eX- terior indicated at 33. lt will be seen that the gasket material is :materially thinned out where it is caught between the `glass iinish 3l a-nd the opposing skirt portion area Zt of the cap shell. As a matter of fact the cap shell in this area is placed under hoop tension as a result of sealing. This condition is indicated in FlG. 7 wherein the original contour of the unapplied cap shell is shown in broken lines while the distended applied condition is shown in fall lines as indicated at 35. rThis hoop tension in the shell places the adjacent gasket material under compression and brings about a very high degree of sealing action in this region.

As indicated above, there are three main sealing areas provided by the gasket lil in combination with the cap shell and the sealing nish on the rim of the container. The rst seal is formed at the feather edge 26. Since this seal is located at a relatively remote distance from the portions of le gasket which are engaged with the glass iinish, and because of the thinness of the feather edge portion and the inability thereof to transmit compression forces, this feather edge seal at Z6 is fully protected and easily maintained so that no part of the atmosphere has an opportiunity to gain entrance between the gasket l@ and the cap shell portion S.

The second portion of the seal is in the area where the thinned out, tapered skirt portion 24 of the gasket is maintained under radial compression between the distended portion 35 ol the cap shell and the unyielding opposing tapered nish 3l. The leakage rate in this portion of the seal is reduced to a minimum since it will be seen that for any part of the atmosehere to pass this seal it will have to traveL through the gasket, not cross-wise or transversely in the narrow direction but lengthwise and parallel to the drawn out portion. Hence, for practical purposes there is no leakage to speak of through this portion of the seal.

Thirdly, there is the cushion seal formed between the upper edge portion 3G orr the glass finish and the thick portion Z3 of the gasket. This is the portion oi the gasket which `hears the greatest load when the package undergoes retorting with high overriding or dilerential pressures.

Heretofore, withother caps having thinner cushions ofv gasket material in this region, it was not uncommon for the high overriding pressures to result in the'gasket being completely penetrated so that the glass linish in eect severed the cushion and reached the metal shell itself. in the gasket lll the amount of material disposed in the channel l5' is sutlicient so as to prevent such penetration from occurring.

arreglos By reason of the padding and cushioning 4action provided by the thick portion 23 of the gasket, the sealed package is able to withstand substantial and repeated impacts and shocks received in generally axial direction. Since the tapered, elongated portion 24 of the gasket is maintained under compression in confined relationship between the glass finish and the cap shell, it is able to withstand substantial impacts from a generally lateral direction. The net result is that a package sealed with the closure cap 6 is more resistant to shocks and impacts without the hermetic seal being 'oroken than caps of this type heretofore provided. Y

The closure cap 6 described above in detail in connection with the accompanying drawings represents the presently preferred embodiment of my invention. However, certain changes may 'be made in it. For example, the cap shell on the lower portion of the skirt could be provided with thread formations rather than the lugs l2 so as to he a screw cap for cooperation with exterior threads on the glass finish. The exterior diameter of the bottom or outermost skirt portion 22 may be reduced somewhat, and -minor variations may he made in the contour of the upper `stepped portion of the shell. Minor variations may he made in proportions.

Since the above and certain other minor changes 4may be made without departing from the spirit and scope of the invention, the foregoing description is intended to be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

l. In a closure cap of the -top and side seal type for use in establishing and maintaining a hermetic seal on a glass container of the type in which the upper edge of the rim together with a portion of the side surface thereof constitute the hermetic sealing finish, and said cap coniprising a generally cup-shaped shell having a top panel portion with the margin having a down-turned channel formation to register with said upper edge and having a stepped skirt portion with the upper inner step thereof integrally joining the outer wall of said channel formation as a continuation thereof and providing a downwardly and outwardly tapered side portion the bottom of which directly joins an outwardly flared shoulderportion, the improvement comprising an annular sealing gasket located generally within the corner of said shell having its upper and inner edge located on the underside of said top panel portion adjacent the bottom of the inner side wall of said channel formation with its lower and outer edge terminating in `a feather edge on the under-side of said outwardly flared shoulder portion, with said gasket filling said channel formation and having a downwardly and outwardly tapered portion which .rapidly diminishes in cross-section below said channel formation and follows said tapered side portion and said outwardly flared shoulder portion and extends to said feather edge, said downwardly and outwardlyr tapered portion being at least several times longer than the thickness of said channel filling portion; said channel filling portion of said gasket sealingly engaging said upper edge of the sealing finish of said container when said closure cap is hermetically sealed thereon with said tapered portion of said gasket being at least partially thinned out by compressed sealing engagement with said side portion of said sealing finish, and said feather edge lying substantially outwardly of said sealing finish.

2. in a closure cap of the combination top and side seal type for use in establishing and maintaining a hermetic seal on a glass container of the type in which the top edge of the rim together with a contiguous downwardly tapered side surface portion having a height approximately equal to the width of said top edge constitute the hermetic sealing finish, and said cap comprising a generally cupsliaped shell having a top panel portion with the margin thereof having a down-turned channel formation to register with said upper edge and having a stepped skirt portion with the upper inner step thereof integrally joining the outer wall of said channel formation as a downwardly and outwardly tapered continuation portion the lower end of which directly joins an outwardly and `downwardly flared shoulder portion of said skirt which connects with the lower outer step of the skirt which carries inwardly projecting formations for retaining the cap on a container, the improvement which comprises an annular sealing gasket located generally within the corner of said shell having its lupper and inner edge located on the underside of said top panel portion adjacent the bottom of the inner side wall of said channel formation and its lower and outer edge terminating in a feather edge on the underside of said shoulder portion, said gasket having an upper cushion portion which fills said channel formation and a downwardly and outwardly ltapered portion which rapidly diminishes in cross-section 1oelow said channel formation and follows said tapered continuation portion of the shell skirt and connects with said feather edge said downwardly and outwardly tapered portion being at least several times longer than the thickness of said channel filling portion, the inner contour of said gasket when uncompressed being generally arcuate from its upper inner edge to the lower end of said downwardly and outwardly tapered portion thereof, said channel filling portieri of said gasket sealingly engaging said top edge of the container rim when said closure cap is hermeticaliy sealed thereon with said tapered portion of said gasket being at least partially thinned out and radially compressed into sealing engagement with said tapered side surface of the sealing finish, and said feather edge portion being disposed substantially outwardly of any portion of said sealing finish, said radial compression on said tapered portion of said gasket being provided by outward flexing of said downwardly and outwardly tapered continuation portion of said skirt.

3. The improvement called for in claim 2 wherein said gasket is formed of a cured plastisol.

4. The improvement called for in claim 2 wherein the inner contour 'of said gasket when uncompressed is generally S-shaped starting at said upper and inner edge and ending at said feather edge.

5. A sealed package comprising a glass container having a hermetic sealing finish provided in part by the top edge of the rim and in part by a contiguous downwardly tapered side surface and having protruding cap-retaining means helow said finish and a closure cap in hermetically sealed relationship on the top of sai-d container, said cap comprising a generally cup-shaped shell having a top panel portion with the margin thereof having a down-turned channel formation in registry with said top edge of said sealing finish and having a stepped skirt portion with the upper inner step thereof integrally joining the outer wall of said channel formation as a downwardly and outwardly tapered continuation portion which telescopes over said tapered side surface of said sealing nish with the lower end thereof directly joining an outwardly and downwardly flared shoulder portion of said skirt which in turn directly joins a lower outer step portion of the skirt which has inwardly protruding `cap-retaining means in engagement with said cap-retaining means on said finish, and an annular sealing gasket locate-d generally within the corner of said shell having its upper inner edge located on the underside of said top panel portion adjacent the bottom of the inner side -wall of said channel formation and its lower and outer edge terminating in a feather edge on the underside of said shoulder portion, said gasket in its compresse sealing condition being generally ladle-shaped in cross-section having an upper cushion portion corresponding to a ladle howl and lling said :channel lfor-ination and having a downwardly `and outwardly tapered portion corresponding to a ladle handle which follows said tapered side portion and said outwardly flared shoulder portion of said shell skirt and extends to said feathered edge, said upper cushion portion sealingly engaging said top edge of sai-d finish and that section of the length of said tapered portion of the gasket which lies between said tapered side surface of the ysealing finish and said 1 ogn-,409

tapered side porion of said skirt being radially thinned Refeemes Ce in the io of this paten out and compressed into saiing engagement with said r QT tapsred side surface by hoop `tonsion provided lby outward UNTLD @LATES PATENTS L- v l f g i a e n rg 0 S51 d d0 @Hardly an@ @1 y f rrdlij raw d Comm 2,453,791; Krueger Man 8, 1949 nation portion of sa1d skirt, and said Ieatner edge portion 5 3 n, 7 04S Foye Jan 16 1962 f um ,L x i ,L L ybolug disposed substanumiy ou-ward1y of amJ porton of 1328,65 Geddes "i APL 3 1962 said seaing finish.

Claims

1. IN A CLOSURE CAP OF THE TOP AND SIDE SEAL TYPE FOR USE IN ESTABLISHING AND MAINTAINING A HERMETIC SEAL ON A GLASS CONTAINER OF THE TYPE IN WHICH THE UPPER EDGE OF THE RIM TOGETHER WITH A PORTION OF THE SIDE SURFACE THEREOF CONSTITUTE THE HERMETIC SEALING FINISH, AND SAID CAP COMPRISING A GENERALLY CUP-SHAPED SHELL HAVING A TOP PANEL PORTION WITH THE MARGIN HAVING A DOWN-TURNED CHANNEL FORMATION TO REGISTER WITH SAID UPPER EDGE AND HAVING A STEPPED SKIRT PORTION WITH THE UPPER INNER STEP THEREOF INTEGRALLY JOINING THE OUTER WALL OF SAID CHANNEL FORMATION AS A CONTINUATION THEREOF AND PROVIDING A DOWNWARDLY AND OUTWARDLY TAPERED SIDE PORTION THE BOTTOM OF WHICH DIRECTLY JOINS AN OUTWARDLY FLARED SHOULDER PORTION, THE IMPROVEMENT COMPRISING AN ANNULAR SEALING GASKET LOCATED GENERALLY WITHIN THE CORNER OF SAID SHELL HAVING ITS UPPER AND INNER EDGE LOCATED ON THE UNDERSIDE OF SAID TOP PANEL PORTION ADJACENT THE BOTTOM OF THE INNER SIDE WALL OF SAID CHANNEL FORMATION WITH ITS LOWER AND OUTER EDGE TERMINATING IN A FEATHER EDGE ON THE UNDER-SIDE OF SAID OUTWARDLY FLARED SHOULDER PORTION, WITH SAID GASKET FILLING SAID CHANNEL FORMATION AND HAVING A DOWNWARDLY AND OUTWARDLY TAPERED PORTION WHICH RAPIDLY DIMINISHES IN CROSS-SECTION BELOW SAID CHANNEL FORMATION AND FOLLOWS SAID TAPERED SIDE PORTION AND SAID OUTWARDLY FLARED SHOULDER PORTION AND EXTENDS TO SAID FEATHER EDGE, SAID DOWNWARDLY AND OUTWARDLY TAPERED PORTION BEING AT LEAST SEVERAL TIMES LONGER THAN THE THICKNESS OF SAID CHANNEL FILLING PORTION; SAID CHANNEL FILLING PORTION OF SAID GASKET SEALINGLY ENGAGING SAID UPPER EDGE OF THE SEALING FINISH OF SAID CONTAINER WHEN SAID CLOSURE CAP IS HERMETICALLY SEALED THEREON WITH SAID TAPERED PORTION OF SAID GASKET BEING AT LEAST PARTIALLY THINNED OUT BY COMPRESSED SEALING ENGAGEMENT WITH SAID SIDE PORTION OF SAID SEALING FINISH, AND SAID FEATHER EDGE LYING SUBSTANTIALLY OUTWARDLY OF SAID SEALING FINISH.