US 3281001 A
Description (OCR text may contain errors)
Oct. 25, 1966 R. STUART 3,
CROWN CAP Filed Feb. 14, 1964 3 Sheets-Sheet l 1 I! it ilk.
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4O \\\\Q [I I 47 33 34 42 l 34% INvENT'Q 44 ROVBERT STUART H by:
R. STUART CROWN CAP Oct. 25, 1966 5 Sheets-Sheet 2 Filed Feb. 14, 1964 ATTV,
I NVEN'I'OR ROBERT STUART R. STUART Oct. 25, 1966 CROWN CAP 5 Sheets-Sheet 5 Filed Feb. 14, 1964 INVENTOR Roses-r STUART ANY.
3,281,001 Patented Oct. 25, 1966 3,281,001 CROWN CAP Robert Stuart, Chicago, Ill., assignor to National Can Corporation, Chicago, 11]., a corporation of Delaware Filed Feb. 14, 1964, Ser. No. 345,019 8 Claims. (Cl. 215-46) This invention relates to caps known as crown caps, for bottles and other types of containers, that is, a cap that has a skirt provided with nibs for engaging an annular bead at the mouth of a container to 'hold the cap in sealing position over the end of the container, the skirt having orirnps to permit stretching of the skirt for releasing the nibs from the bead to remove the cap from the bottle.
This invention is particularly directed to crown caps of the type constructed to facilitate removal of the cap from the container without the use of a special tool, or any tool.
In a crown cap it is the hoop strength of the skirt that is a major factor in holding the nibs against radially outward movement which, if it occurs, will free the nibs from under the bead of the container and permit removal of the cap. In order to remove the cap the skirt must be manually flared outwardly. The prior art contains crown caps that have a number of precut tear tabs which extend from adjacent the junction of the crown portion of the cap with the skirt portion thereof down to a point spaced slightly above the bottom edge of the skirt. When a tab is pulled, the skirt of the cap is torn and its hoop strength is therefore lost. At least two such tear tabs are severed, whereupon the portion of the skirt between two adjacent tabs may be manually forced upwardly to free the intervening nibs from engagement beneath the bead of the pull.
It is one of the objects of the present invention to provide a cap construction which will facilitate the gripping of the tear tab to its tearing position, and which will facilitate the upward forcing of the skirt that is to be forced upwardly.
It is a further object of the present invention to provide an arrangement wherein the .tear tab is so cut or scored that upon pulling of the same to tear the skirt of the cap the tab itself lremains attached to the skirt.
It is a still further object of the present invention to provide a cap of the above mentioned character wherein the operation of placing the cap in its final position on the bottle, that is, capping of the bottle, results in opening of the cut or slit between the edge of the tear tab and the rest of the cap a small amount to facilitate inserting something under the tear tab to flex it into position where it can be gripped. The thing thus inserted under the tear tab may be ones fingernail.
It is still further object of this invention to provide a cap of the above mentioned character wherein the width of the tear tab and the distance between two adjacent pull tabs is such as to facilitate the removal of the cap from the bottle when two tear tabs have been ripped.
It is still further object of invention to provide a tear tab for a crown cap of the above mentioned character wherein the tear tab has one or two wings on the side thereof to facilitate gripping of the tear tab from the sides instead of the ends thereof.
It is a still further object of this invention to provide a crown cap of the above mentioned character wherein score lines or slit lines are provided between adjacent tabs in a particular manner in order to facilitate removal of the cap firom the bottle.
It is .still further object of this invention to provide a cap of the above mentioned character wherein the tear tab produces none or minimal weakening of the pressure of the cap again-st the end of the bottle, thereby maintaining a seal between the end of the bottle and the sealing material on the inside of the cap, even at the tear tabs.
It is still a further object of the present invention to provide an improved blank for caps of the type here involved wherein the additional needed blank material is provided from what was hereto the waste resulting from the stamping operation so that no additional stock is required.
The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the following drawings forming a part thereof.
In the drawing:
FIG. 1 is an enlarged plan view of a cap embodying the present invention;
FIG. 2 is a side view of the cap of FIG. 1;
FIG. 3 is a section taken along the line 33 of FIG. 1 and showing the cap before capping of the bottle;
FIG. 4 is a section taken along the line 4-4 of FIG. 3 before the cap has been placed on a bottle;
FIGS. 5 and 6 are views similar respectively to FIGS. 3 and 5 showing the cap after it has been placed on the end of a bottle;
FIGS. 7 and 8 are views similar to FIGS. 3 and 5 showing a modification of the bottom ends of the pull tab of FIG. 1;
FIGS. 9, l0, and 11 are views similar to FIGS. 3, 4 and 6 respectively showing an alternate construction;
FIG. 12 is a fragmentary plan view corresponding to a portion of FIG. 1, showing a modification of the push tab portion;
FIG. 13 is a fragmentary side view taken along the line 1313 of FIG. 12;
FIGS. 14, 15, 16, 17 and 18 are plan views similar to FIG. 1 but illustrating other embodiments of the present invention;
FIG. 19 is a side view of the cap of FIG. 18;
FIG. 19A is an enlargment of a portion of FIG. 19;
FIGS. 20 and 21 are respectively, plan and side views of a cap illustrating still another embodiment of the present invention:
FIG. 22 is an end view of a cap illustrating another embodiment of the present invention;
FIG. 23 is a section taken along the line 2323 of FIG. 20 after the cap has been fully positioned onto a bottle, and corresponds to the section of FIG. 5;
FIG. 24 is a side view of a cap of still another embodiment of the present invention;
FIG. 25 is a plan View showing the stamping layout for caps having pull tabs and push tabs, as shown in FIG. 1; and
FIG. 26 is an enlargement of a portion of FIG. 25.
Reference may now be had more particularly to the drawings wherein like reference numerals designate like parts throughout.
The caps of the present invention are made of resilient metal, the usual metals being blackplate or tinplate, or aluminum.
In FIGS. 1 through 7, 1 designates a crown cap having a top or crown 5 and an annular skirt 7 that depends from the periphery of the crown and terminates in a rim or free end 9. The bottom portion 13 of the skirt 7 is outwardly and downwardly directed, and, before the cap is placed on a bottle, while the upper portion 15 of the skirt follows a generally cylindrical shape. The skirt 7 is corrugated by circumferentially spaced flutes or ridges 17 separated by valleys 18, as is customary in crown caps. A standard cap has twenty one flutes and twenty one valleys.
Two or more, in this instance three, identical tear tabs 20 are formed in the cap. The tabs are preferably uniformly spaced apart. Each tab is formed by a continuous line of cut 21 that extends between points 23-23 on adjacent flute-s or tabs continuously toward the crown along lines 25, said line of cut then extending outwardly to form short Wings 27-27, the line of out being continuous along a length 28 which is at or near the juncture of the crown with the skirt. The line 28 has a short radially inwardly projecting portion 29. The entire line of cut preferably extends through the entire thickness of the metal of the cap. Theends 23-23 terminate a short distance from the end 9 of the cap, leaving uncut bridges 31-31. These bridges maintain the hoop strength of the skirt, notwithstanding the line of cut 21.
As an optional feature, the cap may, if desired, be formed with uniformly spaced push tabs 33 midway between the tear tabs 20. Each push tab extends across one ridge and approximately one-half of the valley on each side of the ridge.
On the inside of the cap there may be provided any of the usual means for sealing the cap against the top of a bottle such as for instance a flexible gas impervious yielding circular sealing liner 34 which underlies the crown 5. The liner may be cork with an impermeable plastic disk adhesively secured to the underside thereof, and held in place in the cap in any desired manner, or it may be, as is sometimes used, a plastisol sealing coating (polyvinyl chloride of a plastisol grade having a high molecular weight) on the under surface of the crown, the sealing coating being of yielding plastic material which can conform itself to small irregularities in the top surface of the bottle to which the cap is to be secured. This surfacing layer may comprise a disk or only a circular ring coating of plastic (such as plastisol) on the underside of the crown, all of which is standard in the art.
Opposite each tear tab 20 the bottom of the skirt is provided with a short extension 36 which span-s the valley 18 that is included within the circumferential width of the tear tab at the bottom of the skirt. Each extension preferably terminates along lines 38-38 that are in line with the ends of the tear tab cuts 25-25 but spaced therefrom by the bridge portions 31-31. Before the cap is completely applied to a bottle, each extension 36 constitutes a continuation of its corresponding inclined portion 13 of the skirt. During the capping operation the capping tool forces each extension 36 downwardly from the position illustrated in FIGURE 3 to the position illustrated in FIGURE 5. This causes each tab to swing slightly about its bridges 31-31, in a direction counterclockwise with respect to the position illustrated in FIG- URE 3, so that the line of cut tends to open and thereby create a gap 40 between the center of the tear tab and the crown for facilitating fingernail insertion under the line of cut at 29 of the tab 21, when it is desired to remove the crown cap from a bottle, as will hereinafter be explained more fully.
FIGURE shows a portion of the circular top of a bottle 42 to which the cap has been secured. The bottle as, is standard, has an outward-1y extending peripheral bead 43. As is customary, the liner 34 seats on the top of the bottle and is mechanically pressed downwardly during the capping operation to form a seal around the top circular opening of the neck 44 of the bottle. Thereafter, the capping apparatus forces each of the valleys 18 of the skirt of the cap radially inwardly to produce nibs 45 to lock the cap onto the bottle, all as is customary in the art.
Each of the push tabs 33 has a portion 46 projecting downwardly from the bottom portion of the skirt of the cap. This downwardly projecting portion 46 is mechanically flexed radially inwardly to a position 47, during the capping operation. This provides a push-up surface, for the finger, thus avoiding the cutting action of the sharp metal edge of the skirt of the cap.
When it is desired to remove the cap from a bottle to which it is affixed, the user bends each of tabs outwardly. This may be accomplished by inserting his fingernail under the projecting portion 29 at the gap 40 and first flexing the tab radially outwardly and then pulling the tab downwardly to tear the bridge portions 31-31, as in United States Patents 3,118,556 or 1,889,210. As an alternate, the wings 27-27 may be utilized for accom plishi-ng the same result. The gap 40 that is created at each tab extends along the wings 27. The Wings facilitate a bridging action on the tab by inserting the fingernail of the thumb and forefinger under the two .wings simultaneously.
Once one of the tabs has been severed, the hoop strength of the skirt is destroyed, and it is then possible to push upwardly on the base of the crown at the section therof that is between adjacent gaps formed by removal of the tabs, to force the corresponding sector of the skirt upwardly olf the bottle bead 43. To facilitate this upward pushing action, the push tabs 33 are, optionally, provided. The inwardly flexed end 46 of the tab that is in the position illustrated at 47 in FIG. 6 prov-ides a push up surface for the operators finger.
If desired, the wings 27-27 may be omitted from the tabs 20 so that the line of cut at 29 of FIG. 1 is a direct continuation of the lines of cut 25-25.
It is further understood that the push up tabs 33 may be used on crown caps having specifically differently constructed pull tabs, for instance on crown caps having pull tabs, the construction of which is illustrated in Patent 3,118,556.
FIGURES 7 and 8 illustrate a modification of the base of the pull tab of a cap such as shown in FIGS. 1 and 2. In this instance the bottom extension 36 of the tab is initially bent downwardly as illustrated in FIG. 7. During the capping operation this portion 36 may, optionally, be flexed inwardly as illustrated at 36a in FIG. 8. This slight inward flexing may produce a slight opening 40' (FIG. 8) as the tab pivots about the bridges 31-31 of FIG. 2 Late-r, when the cap is to be removed from the bottle, the portion 36a may be pushed manually radially inwardly towards the bottle, thus enlarging the opening 40', or at that time creating it if there is no such opening.
FIGS. 9, 10 and 11 show a modification of the push up tab 33 of FIG. 1. This modification consists of providing a curl 50 at the bottom of the push up tab 46 to reduce the possible cutting action of the metal of the push up tab on the finger that is exerting pressure to push it upwardly. This push up tab is in the position illustrated in FIGS 9 and 10 before capping of the bottle and in the position illustrated in FIG. 11 after the bottle has been capped.
FIGS. 12 and 13 illustrate a still further modified form of push up tab for a cap such as shown in FIG. 1. In this instance the push up tab is provided with a slot 52 in line with ridge 17 that is spanned by the push up tab. This avoids any possible interference of the push up tab with the crown forming operation-during the forming of the cap. Each push up tab now comprises two short tabs 53-53, each of which may, optionally, have a curl formed at the base thereof corresponding to the curl 50 of FIGS. 9 and 10.
The crown cap of the present invention may be provided with score or groove lines to facilitate removal of the cap from the bottle. In FIG. 14 the cap is shown provided with lines of cut 56 extending radially inwardly from the centers of the respective tabs as in United States Patent 3,118,556. The lines 56 may be cut through the entire thickness of the metal, or they may be merely score lines extending through approximately one half I the thickness of the metal, Which will accomplish the weakness 62. This line of weakness may be a score line extending through half the thickness of the metal or may be a line of perforation extending through all or half of the thickness of the metal. There may be three, two, or only one line 62. In each of the constructions of FIGS. 14 and 15 and 16, the lines 56 or 60' or 62 extend to the centers of their associated tabs.
In FIG. 17 the line of weakness 63 extends between adjacent wings 21 of the tear tabs instead of between the centers of the tear tabs.
FIGS. 18 and 19 show a crown cap of the type illustrated in FIG. 1 wherein the line of cut which defines the tear tab terminates closer to the bottom of the rim at one end of the line of cut than at the other. The line of cut defining the tear tab is indicated at 70. The bridges 31a and 31b which correspond to the bridges 31-31 of the cap of FIG. 1, are here of difierent widths. Here only one wing 27 is provided, although two such wings, as in FIG. 2, may be provided, or none may be provided. One end of the line of cut terminates at 73 and the other end terminates at 74. The terminus 73 is closer to the bottom of the cap than is the terminus 74. As a result, when the tab is being pulled the bridge 31a will be the first to tear and, by making the bridge 31 sufliciently great, that bridge will not tear at all. This is facilitated by providing the one (instead of two) wings 27 for the tab. When the tab is pulled at the wing 27 and the bridge 31a tears, the hoop strength of the skirt is lost and thereupon the cap may be removed as in the case of the cap of FIG. 1, or in the case of the caps of the patents hereinabove referred to. The pull tab 20 itself remains attached to the cap so that there are no severed small pieces of metal. In other respects the cap of FIGS. 18 .and 19 may be the same as the cap of FIG. 1 or, for that matter, it may be the same as the cap of Patent 3,118,556 except that the bridges 31a and 31b are made of unequal lengths so that the tab remains affixed to the rest of the cap when the tab has been torn preparatory to removal of the cap from the bottle.
FIGS 20 and 21 show another arrangement of crown cap of the present invention. In this case the cap has three pull tabs 20b each of which spans the distance between the centers of three adjacent ridges 17. The line of cut in this instance is indicated by the reference numeral 80 which spans two valleys 18-48 of the cap skirt. The line of out follows the apices of the corresponding spaced ridges 1717 with an intervening ridge 17 between them. In this instance, as in the previous caps, the skirt of the cap has twenty one ridges 17. There are, therefore, five valleys between adjacent tabs. If two of the tabs are severed, the gaps in the skirt that is thereupon produced, is of an arcuate width of of the arcuate extent of the skirt or somewhat more than 150 degrees. The space on the skirt between the pulled off tabs is only of the arcuate extent or somewhere in the order of 90 degrees. It is, therefore, quite easy to push up on the portion of the skirt between two pulled away tabs. The remaining portion of the skirt on the other side of the pulled off tabs is only a small amount more than 180 degrees, and can readily be pushed off of the bottle.
In crown caps of the type mentioned above, where the tab extends to the crown, there is necessarily a reduction in the pressure of the cork sealer 34 against the top of the bottle 42 at the place where the tab is cut. It may be desirable to reduce the possibility of leakage at those places where the metal of the cap is less restrained against outer flexing caused by gas pressure of the product in the bottle, as in the case of a carbonated beverage. The embodiment of FIGS. 22 and 23 serves to reduce any tendency for leakage past the liner 34 at the pull tab. In this embodiment the top of each pull tab 200, which corresponds to the pull tab 20 of FIGS. 1 and 2, terminates along the line 290 which is appreciably below the top of the crown so that the gap 40c which corresponds to the gap 40 of FIG. 5, is below the top of the crown and leaves a flange projecting below the top of the crown and a continuation of the skirt at the pull tab. This flange resists outward flexing of the metal of the crown cap at the pull tab.
FIG. 24 shows a crown cap that utilizes the pull tabs heretofore described and which is of the construction such as was heretofore described, differing therefrom only in that the push up tabs are entirely omitted, and in lieu thereof a film 86 of plastic material coats the bottom of the skirt and thereby inhibits cutting of ones finger when ones finger is used to push upwardly on the skirt after the tabs have been torn away as above described and as described in Patent 3,118,556 to which the principles of FIG. 24 are also applicable. The coating of plastic 86 at the rim of the cap may be a thickness of the order of a few hundredths of an inch. It may be a clear transparent plastic which would be only very slightly visible, if atall. The coating may be of any plastic material which will not chip from the cap during the capping operation. A suitable plastisol grade of polyvinyl chloride of high molecular weight may be used, the film being one which is resilient but not tacky. It may be coated on the surface of the cap upon completion of the fabrication thereof and before the bottle is capped, at the same time that a similar plastisol is being applied as a sealing ring or sealing disc on the inner surface of the crown cap, as described in United States Patent 2,937,404 to which reference may be had.
The present invention contemplates the application of a thin layer of plastic material to the bottom edge of any standard type of crown cap to reduce the sharpness of the crown cap. It may be a standard crown cap without pull tabs, or it may be a crown cap with pull tabs, such as hereinabove described or as described in the prior art of which United States Patents 1,899,210 and 3,118,556 are representative. The film may be applied to the rim of the cap in any desired manner.
Reference may now be had more particularly to FIG. 25 which shows a plan view of a sheet of metal from which blanks are stamped to form the cap of FIG. 1. The blanks, indicated at 95, are stamped from a sheet of metal 96 which may be of a width sufiicient to form many blanks, for instance six such blanks. The sheet is stamped in the customary manner so as to provide a minimum of waste, as illustrated in FIG. 25. There is a certain amount of waste material at each crotch where three blanks are adjacent to one another. This is indicated by the reference numeral -97. It is out of this waste material that a small piece of metal 98 is taken, that piece being left as part of each of the three blanks meeting at that corner. These pieces of metal 98 constitute the lowermost parts 36 of the tear tabs or the lowermost parts of the push up tabs. Each one of these tabs may be made of an arcuate length not to exceed the maximum arcuate length available in the waste space 97 while allowing the usual amount of clearance between adjacent stampings. For instance, in one cap wherein the diameter of the blank for making the crown cap was 1.5 inches, each one of the six tabs formed on each blank was of a circumferential width approximately A inch and projected beyond the periphery of the blank a distance of .08 inch with the corners suitably rounded. In this blanking operation, the minimum distance between adjacent stampings (which was determinative of the amount of scrap) was .03 inch.
It is understood that the invention is not limited to the precise embodiments herein shown, the same being merely illustrative of the principles of the invention. What is considered new and sought to be secured by Letters Patent is:
1. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting from the crown, said skirt forming a continuous hoop distendable radially inwardly into gripping engagement under a bead on a container neck to hold the cap in place on the container neck, and said body having tear tabs to facilitate removal of the cap from the container neck, said tabs projecting from adjacent to the base of the skirt toward the crown and each being defined by a generally U-shaped slit in the body with the bight of the U adjacent to the juncture of the skirt and crown, one of said terminal points being closer to the base of the skirt than the other, said bight including a portion thereof that extends within the skirt laterally of the side of the tab that is defined by that portion of the slit that terminates closest to the free end of the skirt to define a tab wing extending circumferentially of the skirt only from said last-mentioned side of the tab and adjacent to said crown to facilitate tearing of the tab by initiating a pull on the tab wing and then pulling the tab radially and circumferentially, thereby to break the skirt in the region of the skirt between said free end and said closest terminal points while leaving the tab attached to the skirt in the region of said other terminal points.
2. A crown cap according to claim 1 in which there is a score line extending from each said bight into the crown.
3. A crown cap according to claim 1 in which the body has a slit extending from each said bight into the crown.
4. A crown cap according to claim 1 in which there is a score line extending across the crown from approximately the center of one bight to the corresponding point on an adjacent slit.
5. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown, said skirt being corrugated by circumferentially spaced flutes formed in and extending from adjacent to the free end of the skirt toward the crown with the skirt forming a continuous hoop sothat the skirt may be distended radially inwardly along its circumference into gripping engagement with a bead on a container neck to .hold the cap in place on the container neck, and tear tabs on the body to facilitate removal of the cap from the container neck, said tabs each being circumferentially spaced around the skirt and each being joined to the skirt by means that leaves hoop strength in the skirt so that each tab may be pulled to rupture said means, said free end of the skirt being a raw edge of metal that is substantially entirely enclosed by plastic.
6. A crown cap comprising a body having a crown and a peripheral skirt surrounding and projecting away from the crown, said skirt forming a continuous hoop that may be distended radially inwardly into gripping engagement with a bead on a container neck to hold the cap in place on the container neck, and tear tabs on the body to facilitate removal of the cap from the container neck, said tabs each being defined by a line of weakness with the ends of the line defining the sides of the tab and terminating at spaced points adjacent to but spaced from said free end of the skirt and extending from there toward the crown so that each tab may be pulled to tear the part of the skirt between at least one end of the slit and the free end of the skirt, each tab being approximately coincident with said body piror to mounting of the cap onto the container neck and with the end of the tab opposite to said spaced points forming a narrow gap when the cap is mounted on said bead, each tab including an extension that projects generally axially beyond said free end of the skirt and is of a width approximately equal to the width of said tab at said spaced points, each extension constituting a force receiving surface for a capping tool to facilitate bending its associated tab radially outwarly to widen the gap between the end of the tab and the adjacent part of the crown when the skirt is distended into gripping engagement with said bead.
7. A crown cap according to claim 6 in which the extension, prior to said distention of the skirt, is a generally frusto conical element.
8. A crown cap according to claim 7 in which said extension further includes a generally cylindrical element at the end of said conical element.
References Cited by the Examiner UNITED STATES PATENTS 1,131,676 3/1915 Cake 113-121 1,257,992 3/1918 Gavaza 113-121 1,899,210 2/1933 Ramsay 215--46 1,996,554 4/1935 Shearwood 215-46 2,156,258 5/1939 Atwood 215-46 2,433,629 12/1947 Shannon 215-46 2,563,176 8/1951 Kline 215-46 3,118,556 1/1964 Amato et a1. 215-46 3,145,869 8/ 1964 Ritzenhoif 220-54 3,155,262 11/1964 Cros 215-46 THERON E. COND-ON, Primary Examiner.
FRANKLIN T. GARRETT, Examiner.
J. B. MARBERT, Assistant Examiner.