US3207351A - Crown cap - Google Patents

Description

Sept. 21, 1965 R. STUART 3,207,351

CROWN CAP Filed May 5, 1964 @xvwv QA@ '1mg 9 mvENToR.

United States Patent O Filed May 5, 1964, Ser. No. 365,040

15 Claims. (Cl. 21S-46) The present invention is a continuation-impartv of my copending application, Serial No. 352,619, filed March 17, 1964, and the entire disclosure in that application is by reference incorporated herein.

This invention relates to improvements in crown caps of the type that may be removed from a container upon which the cap is mounted without the use of an opening tool.

It is an object ofthe present invention to provide a crown cap having tear tabs which may be manually grasped and by which the body of the cap may be torn ina plurality of places to break the hoop strength of the cap so that the cap may thereafter be readily removed from the container.

It is a further object of the present invention to provide a crown cap of the type stated in which the tabs are spaced circumferentially about the skirt of the cap body, and wherein there is a generally linear zone of weakness in the body that extends from each tab to an adjacent tab, which zone of weakness runs chord-wise across the crown of the cap so that after tearing of the tabs,`one part of the cap body may be bent upwardly relative to another part of the body along the zone of weakness to facilitate removal of the cap from the container.

It is a more specific object of the present invention to provide a crown cap of the type stated in which each chord-wise extending zone of weakness is of variable weakness with the greater weakness being either at the periphery of the crown or at the central part of the crown. If the weaker part of the zone is at the periphery of the crown and the stronger part is at the central part of the crown, the crown has improved strength at its central part to inhibit bulging of the crown thereat when the interior of the container is under pressure, as for instance, when the container is filled with a carbonated beverage. Conversely, if the weaker part of the zone is at the central part of the crown, some sacrifice of the strength of the central part of the crown is made,but at the same time,

it is easier t-o bend the cap'around the zone of weakness. In accordance with the principles of the present invention, the variation in weakness in the zones of weakness may be accomplished by forming in the crown a chordal score line of a depth which varies from a minimum or leven zero at one end of the chord to a maximum at the other end of the crown. The zone of weakness may also be formed by a score line extending from the periphery of the crown inwardly thereof for only a short distance or by scoring a part of the crown such that the ends of the score line stop short of the periphery.

The attainment of the above and vfurther objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawing forming a part thereof.

In the drawing;

FIG. 1 is a top plan view of a crown cap constructed in accordance with and embodying the present invention;

FIG. 2 is a perspective view of the crown cap shown mounted on a container;

FIG. 3 is a fragmentary side elevational view on an enlarged scale of the cap and container shown in FIG. 2;

FIG. 4 is `a fragmentary sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a fragmentary sectional view taken along line 5-5 of FIG. 2;

FIG. 6 is a fragmentary sectional view similar to FIG.

3,207,351 Patented Sept. 2l, 1965 ICS 5 but showing a modified form of the present invention;

FIG. 7 is a perspective view of another modified form of cap shown mounted upon a container;

FIG. 8 is a fragmentary sectional view taken along line 8-8 of FIG. 7; and

FIGS. 9 and l0 are sectional views similar to FIG. 8 and showing two additional modified forms of the present invention.

Referring now in more detail to the drawing, 1 designates a crown cap that comprises a body 3 of metal, such as aluminum, tinplate, blackplate or the like, having a circular top or crown 5 and an annular skirt 7 that depends from the periphery of the crown 5 and terminates in a rim or free end 9. The bottom portion 13 of the skirt 7 is outwardly directed and generally conical while the upper portion 15 of the skirt is generally cylindrical. The skirt 7 is corrugated by circumferentially spaced flutes 17 that extend from the free end 9 upwardly toward the crown 5. The utes 17 extend across the lower porcurved juncture of the skirt 7 and crown 5. The end portions 25, 27 of each slit define the sides of a tab 21, and the end portions 25, 27 terminate at spaced points above the free end 9 of the skirt 7, thereby to leave bridges 29, 31 of solid metal between the terminals of the end portions 25, 27 and the free end 9 of the skirt. The end portion 25 terminates closer to the free end 9 than does the end portion 27 whereby the bridge 29 is shorter than the bridge 31, and for purposes presently more fully appearing. The end portions 25, 27 may lie along the ridges of two adjacent flutes, or where a wider tab is desired, may lie along two alternate utcs so that a ute lies between the end portions 25, 27.

Formed in the body and extending across the crown 5 from each tab 21 to an adjacent tab, are three generally linear zones of weakness 33, 33, 33. In the form of the invention shown in FIGS. l-5, each zone of weakness 33 comprises a score line 35 that extends chord-wise across the crown 5. The three score lines 35, 35, 35 intersect to form an equi-lateral triangle with the apices 37, 37, 37 of the triangle lying in the crown or approximately in the curved region of the juncture of the skirt 7 and crown 5L A line of weakness in the body 3, such as a score line 39, extends from each apex 37 downwardly along the upper portion 15 of the skirt 7 to approximately the middle of the slit 19 of the adjacent tab 21. In the drawing, the widths of the score lines are shown exaggerated for purposes of clarity of illustration.

Each score line 35 is of variable depth so that each zone 33 is of variable weakness across the crown. As shown in FIG. 5, the depth of the score line 33 is a maximum at each apex 37 and tapers to a minimum depth at 41 midway between the two apices 37, 37. The score line 39 may have a depth which is approximately the same as that at the apex 37. By way of example but not of limitation, the maximum depth of the score line 33 may be about three fourths the depth of the metal, and the minimum depth may be about one half the depth of the metal. Accordingly, crown 5 has greater strength in its central portion than at its periphery.

FIGURE 6 shows a modified zone of weakness in a cap which is otherwise identical to the cap previously described. However, in a cap of the type shown in FIG. 6,

Conventionally the cap has twenty one l the depth of each score line 43, y44 diminishes to zero at the midpoint 41 of the chord so that, in effect, the score lines are short Vs extending from each apex 37.

FIGS.,7 and 8 show a further modified form of cap which is identical to the cap of FIGS. lexcept as to the construction of the zone of weakness 33a. In FIG- URES 7 and 8, score lines 45, 47 form a V extending from each apex 37 into the crown. Each score line 45 is in alignment with the score line 47 running from the adjacent apex 37. As best seen in FIG. 8, the score lines v45, 47 are of uniform depth for substantially the fulll length of each, and with each score line 45, 47 extending approximately one third the distance between apices 37, 37 so as to leave in the crown an unscored region 49 in the zone of weakness 33a between the adjacent terminals 51, 53 of the score lines 45, 47. The depths of the score lines 45, 47 may, however, taper from the apices to a lesser depth at their terminals 51, 53 or the depths may taper to zero at the terminals 51, 53.

FIGS. 9 and 10 show zones of variable weakness extending between tabs 21 in which each zone is weaker -at the central part of the crown 5 than at the periphery thereof, to enhance the ease of bending the cap about the zone of weakness 33b after tearing the tabs 21, as will presently be more fully described. In FIG. 9 a score line lies approximately midway between two apices 37 with the ends of the score line terminating in spaced relation to the apices 37. The score line 61 may have any suitable depth that is the same or greater than the depth of score at the apices 37, 37 of the-zones of weakness 33b. These apices 37, 37, 37 are, however, in this form of the invention merely the upper ends of the score lines 39, 39, 39.

In FIG. l0 the cap has a zone of weakness 33e that i is defined by a score line 63 that extends between apices 37, 37 and has a depth that increases from a maximum at the center 65 of the score line to a minimum at the apices 37, 37. By way of example but not of limitation, the depth of the score line 63 may be about three fourths the thickness of the metal as a maximum and about one half the depth of the metal as a minimum.

Thev cap 1 has a conventional flexible, gas impervious yielding sealing liner underlying the crown 5 of a diameter approximately that of the internal diameter of the skirt at the crown. The liner 55 may be of cork Withan impermeable plastic disc adhesively secured to the underside thereof and held onto the cap in any standard manner. Alternatively, the liner 55 may be a vinyl plastisolof the type disclosed in U.S. Patent 2,937,404.

The cap 1 may be mounted on the container 57 by conventional high speed capping machinery. During the capping operation, the skirt 7 is radially outwardly flexed to snap over the container bead S9 and then moves under its natural resiliency, or is mechanically moved, radially inwardly into gripping engagementwith the underside of the container bead 59 to hold the cap onto the container bead 59 by the hoop strength of the distended cap skirt. A gap 61 is formed between the upper end 23 of the tab 21 and the part of the skirt therebehind. The portions of the skirt between the flutes 17 engage the bottle bead, and the gripping of the container at the skirt also presses the sealing liner 55 downwardly into firm sealing engagement with the top of the container bead 59.

When it is desired to remove the cap 1 from the con- -tainer bead 59, the tear tabs 21 are grasped by inserting the linger-nail behind the upper ends 23 of the tabs, as at gaps 61, whereupon the tabs are pulled outwardly and downwardly. This tears one or more of the bridges 29, 31 of metal adjacent to each of the respective tabs 21 and thereby breaks the hoop strength of the skirt. Since the bridge 29 is shorter than the bridge 31, tearing of the bridge 29 is more easily effected, and there is a great likelihood that only the region 29 will be completely torn, leaving the tab attached to the skirt ut the region 31. The cap 1 may then be removed from the container bead 59, and to facilitate such removal, a part of the body may be bent upwardly along one or more of the zones of weakness 33, or 33a, 33b, or 33C, as the case may be.

While I have herein illustrated three tabs equally spaced about the cap body with three zones of weakness extending across the cap, a greater or lesser number of tabs may be used. For example, if four tabs are used, the four zones of weakness will intersect at apices and lform a quadrilateral. If two tabs are used, they may be spaced degrees apart with a single zone of weakness extending between them and across the crown 5. Moreover, where more than two tear tabs are used they need not be equally spaced about the cap body but no two adjacent tabs should be more than about 180 degrees apart.

In compliance with the requirements of the patent statutes, I have herein shown and described a preferred embodiment of the present invention. It is, however, to be understood that the invention is not limited to the precise construction herein shown, the same being merely illustrative of the principles of the invention. What is new and considered to be secured by Letters Patent is:

1. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for gripping engagement with a container neck to retain the cap thereon, tear tabs on the body to facilitate removal of the cap from the container neck, said tabs being circumferentially spaced about the body and each being defined by a line of weakness with the end portions of the line dening the sides of the tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown, and means forming a zone of weakness in the body extending substantially from each tab to an adjacent tab and through the crown, each zone being of variable weakness and constituting a line about which the body may be folded after tearing of the body by the tear tabs and with at least part of each line of fold being formed by a score in the crown.

2. A crown cap according to claim 1 in which the depth of the score varies from the part of the zone remote from the tabs to the parts of the body adjacent to the tabs.

3. A crown cap according to claim 1 in which the zone of weakness includes an unscorcd region in the crown.

4. A crown cap according to claim 1 in which the zone is of greater weakness adjacent to the tabs and is of lesser weakness in the crown remote from each tab.

'5. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for gripping engagement with a container neck to retain the cap thereon, at least three tear tabs on the body to facilitate removal of the cap from the container neck, said tabs being circumferentially spaced about the body and each being defined hy a line of-weakness Iwith the end portions of the line defining the sides of the -tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown, and means forming a zone of weakness in the .body extending substantially from each tab to each adjacent tab and through the crown, the zones intersecting to deline a polygon having apices respectively adjacent to each talb, each zone being of variable weakness and constituting a line about which the body may be folded after tearing of the tear tabs, and a line of weakness in the 'body extending from eac-h apex to the adjacent tab.

6. A crown cap according to claim 5 in which at least one of the zones of Weakness is formed 'by a score line extending between two apices, the depth of the score varying from each apex toward the part of said zone ap proximnlcly midway between the two apices.

7. A crown cup according to claim S in which n zone 5 of weakness includes a score line in the crown and an unscored region in the crown.

8. A crown cap according to claim in which the zone of weakness includes a score line between the apices and an unscored part of the crown between the ends of the score line and the adjacent apices.

9. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for grippingengagement with a container neck to retainthe cap thereon, tear tabs on the body to' facilitate removal of the cap from the container neck, said tabs being circumferentially spaced about `the body and each being defined by a line of weakness with the end |portions of the line defining'the sides of the tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown and with an intermediate portion of the line defining an end of the tab that is within the skirt, a line of weakness extending from each said end of the tab and terminating in the crown, and a zone of weakness extending over the crown from t-he crownterminal of each of said .last mentioned score lines to the crown-terminal of an adjacent score line and constituting a generally linear zone about which the cap may be folded to 'facilitate removal of lthe cap lfrom the container after tearin'g of the tear tabs, each zone of weakness including at least one score line and being of variable weakness with the greater weakness being at said crown terminals and a lesser weakness intermediate said cro-wn terminals.

10. A crown cap according to claim 9 in which the score line intersects two of said crown terminals and is of progressively decreasing depth in a direction away from eac-h said crown terminal.

' 1'1. A crown cap Iaccording to claim 9 in which there is a score line extending from each of the crown terminals toward another crown terminal and ending in spaced relation to each other.

. 12. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for gripping engagement with a container neck to retain the cap thereon, tear tabs `on the body to rfacilitate removal of the cap from the container neck, said tabs being-circumferentially spaced about the body and each being defined by a line of weakness with the end portions of the line defining the sides ot the tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown, and means forming a zone of weakness in the body 'between two tabs and about which one part of the body may be bent relative to the other after tearing of the skirt by the tear tabs, said zone of weakness including a score line extending chordwise across the crown and Vbeing of variable depth with the depth of the score being a maximum at the ends of the chord and being a minimum substantially at the middle of the chord.

13. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for gripping engagement with a container neck to retain the cap thereon, tear tabs on the ibody to facilitate removal of the ca'p from the container neck, said tabs being circumferentially spaced about the body and each being defined by a line of weakness with the end portions 0f the line defining the sides of the tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown, and means forming a zone of weakness in the body between two adjacent tabs and about which one part of the body may be bent relative to the other after tearing of the skirt by the tear tabs, said Zone of weakness extending chord-wise across the crown and including two aligned score lines extending from the periphery of the crown toward each other and terminating at spaced points within the crown and leaving the part of the crown therebetween Unscored.

.14. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown and adapted for gripping engagement with a container neck to retain the cap thereon, tear. tabs on the body to facilitate removal ofthe cap from the container neck, said tabs being circtunferentially spaced about the body and each being defined by a line of weakness with end portions of the line defining the sides of the tab and terminating at spaced points adjacent to but spaced from the free end of the skirt and extending from there toward the crown, and means forming a zone of weakness between two tabs and constituting a line about which one part of the lbody may be bent relative to the other after tearing of the skirt by the tabs, said zone being of variable weakness with the greater weakness being in the part of the zone remote from the tabs and the lesser weakness ibeing in the part of the zone adjacent to the tabs.

15. A crown cap according to claim 14 in which the zone of weakness is formed by a score line the depth of which progressively increases from a lesser depth adjacent to each tab to a greater depth in the part of zone Vremote from the tabs.

References Cited by the Examiner UNITED STATES PATENTS kFRANKLIN T. GARRETT, Primary Examiner.

Claims (1)

1. A CROWN CAP COMPRISING A BODY HAVING A CROWN AND A PERIPHERAL SKIRT SURROUNDING AND PROJECTING AWAY FROM THE CROWN AND ADAPTED FOR GRIPPING ENGAGEMENT WITH A CONTAINER NECK TO RETAIN THE CAP THEREON, TEAR TABS ON THE BODY TO FACILITATE REMOVAL OF THE CAP FROM THE CONTAINER NECK, SAID TABS BEING CIRCUMFERENTIALLY SPACED ABOUT THE BODY AND EACH BEING DEFINED BY A LINE OF WEAKNESS WITH THE END PORTIONS FOR THE LINE DEFINING THE SIDES OF THE TAB AND TERMINATING AT SPACED POINTS ADJACENT TO BUT SPACED FROM THE FREE END OF THE SKIRT AND EXTENDING FROM THREE TOWARD THE CROWN, AND MEANS FORMING A ZONE OF WEAKNESS IN THE BODY EXTENDING SUBSTANTIALLY FROM SAID TAB TO AN ADJACENT TAB AND THROUGH THE CROWN, EACH ZONE BEING OF VARIABLE WEAKNESS AND CONSTITUTING A LINE ABOUT WHICH THE BODY MAY BE FOLDED AFTER TEARING OF THE BODY BY THE TEAR TABS AND WITH AT LEAST PART OF EACH LINE OF FOLD BEING FORMED BY A SOCRE IN THE CROWN.

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