US3743129A - Tear-off closure with reinforcing rib - Google Patents

Abstract

A tear-off closure is provided which has a top end wall and a depending skirt and having a tear strip defined by scoring divisive of the end wall and into the skirt, the tear strip having at least one embossed rib therein which extends from a location toward the center of the closure radially outward to a location adjacent the shoulder of the closure between its end wall and the skirt to ensure severance of the tear strip over such shoulder of the closure. The closure may further have a raised rim around a recessed central panel in its top end wall, with the rib in the tear strip extending from the recessed central panel into the rim of the closure.

Description

United States Patent [191 Willis et all TEAR-OFF CLOSURE WITH REINFORCING RIB [75] Inventors: WiIburn C. Willis, Richmond, 1nd.;

Robert L. LaBal-ge, Ben Avon, Pa.

[73] Assignee: Aluminum Company of America, Pittsburgh, Pa.

[22] Filed: Mar. 5, 1971 [21] Appl. No.: 121,467

[52] US. Cl. 215/46 A, 220/54 [51] Int. Cl B6511 43/02 [58] Field of Search 215/46 A; 220/54,

[56] References Cited UNITED STATES PATENTS 3,556,336 1/1971 Coop 215/46 A [451 July 3,1973

Primary Ekaminer-GeorQe T. Hall Atlorney-David W. Brownlee 5 7 ABSTRACT A tear-off closure is provided which has a top end wall and a depending skirt and having a tear strip defined by scoring divisive of the end wall and into the skirt, the tear strip having at least one embossed rib therein which extends from a location toward the center of the closure radially outward to a location adjacent the shoulder of the closure between its end wall and the skirt to ensure severance of the tear strip over such shoulder of the closure. The closure may further have a raised rim around a recessed centralpanel in its top end wall, with the rib in the tear strip extending from the recessed central panel into the rim of the closure.

9-Claims, 10 Drawing Figures PATENIEIJJUL 3191a 3.743.129

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INVENTORS. W/LBURN C. WILL/5 8 ROBERT L. LABARGE QMW AI forney TEAR-OFF CLOSURE WITH REINFORCING RIB BACKGROUND OF THE INVENTION It is known to provide a tear-off closure which has a tear strip across its end wall and into its skirt, and a pull tab attached to the tear strip as is shown in LaBarge et al. US. Pat. No. 3,441,163 and Schay US. Pat. No. 3,353,739. Such closures frequently include means such as a recessed panel in the end wall and a rim around the recessed panel to protect the tab from accidental opening. With this closure structure, there has been some difficulty in ensuring that severance of the tear strip will follow the score line over the rim of the closure between its end wall and skirt. The rim of the closure produces a resistance to rupture of the score line which may result in premature severance of the tear strip from the closure. An attempt was made to correct this problem by providing an upwardly embossed island in the tear strip adjacent to, but not extending into, the rim of the closure toform a lever in the tear strip. Although this embossed island improved the opening characteristics of the closure, the closure was not completely foolproof. In some cases, the tear strip would be severed from the closure at the top of SUMMARY OF THE INVENTION This invention provides a tear-off closure which has a tear strip across its end wall and into its skirt, and which has at least one embossed rib in the tear strip starting in a center portion of the closure and extending outwardly to a location adjacent the shoulder of the closure between its end wall and skirt to aid in severing the tear strip over the corner of the closure and form a partially split closure member which can be lifted from the container.

Accordingly, an object of the invention is to provide an improved tear-off closure which eliminates the problem of premature separation of the tear strip from the closure.

Another object of the invention is to provide a closure which has at least one embossed rib in its tear strip to aid in severing the tear strip over the corner of the closure.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the invention will be further understood and appreciated with reference to the following description and drawings attached thereto wherein;

FIG. 1 is a top plan view of a closure of the invention on a container;

FIG. 2 is a partial elevation view of the closure and container of FIG. 1;

FIG. 3 is a partial cross-sectional view of the closure and container of FIG. 1 taken along line III-III;

FIG. 4 is a partial cross-sectional view of the rib in the closure of FIG. 1 taken along line IV-IV;

FIG. 5 is a partial perspective view of the closurecontainer combination showing partial opening of the closure;

FIG. 6 is a partial cross-sectional viewsimilar to FIG. 5 showing further severance of the tear strip;

FIG. 7 is a top plan view of an alternative form of closure of the invention;

FIG. 8 is a partial cross-sectional view of the closure and container of FIG. 7 taken along line VIII-VIII;

FIG. 9 is a partial cross-sectional view of a rib in FIG. 7 taken along line IX--IX; and

FIG. 10 is a partial vertical cross-sectional view of the closure-container of FIGS. 7 and 8 showing severance of the tear strip.

DESCRIPTION OF PREFERRED EMBODIMENTS In the several illustrations appended hereto, metal closures or closure fitments are shown in the form of permanently deformable drawn metallic shells each of which has a top portion and a depending skirt terminating in a circumferential bead, and having a tear strip with a lever type pull tab affixed thereto divisive of the closure fitment to facilitate removal of the fitment. A cup-shaped liner of a resilient plastic material may be provided within such a fitment to form a closure assembly. A container with entrance mouth is illustrated as a conventional open top jar, bottle, or the like, made of glass, plastic or like material, and suited to have such a closure assembly affixed thereto.

Referring to the illustrations, FIGS. 1, 2 and 3 showa a closure fitment 10 formed from sheet metal or other permanently deformable material, and preferably from a thin sheet of aluminum or an alloy thereof, which is adapted to be secured over the entrance mouth of acontainer 12. Closurefitment 10 is comprised of atop end wall 14 and a dependingskirt 16 terminating in acircumferential bead 18. Theclosure fitment 10 is weakened or scored alongline 20 to form or define atear strip 22 divisive of the closure top from a starting location adjacent or towards the periphery of the top relative to its center, to a generally opposite location, and from there divisive of the closure fitment along one side of thetear strip 22 all the way to the edge of the sheet material of the fitment, and along the other side of thetear strip 22 to a location short of the edge of the sheet material leaving a bridge or ligament of unscored metal between its end and the bottom of theskirt 16. Theclosure fitment 10 may also be scored outwardly of and adjacent to the starting end of thetearing strip 22 by means of twoscores 24.Scores 24 intersect theprimary score 20 on opposite sides of the apex of thetear strip 22, and extend from the primary score outwardly to the shoulder or corner between theend wall 14 and theskirt 16 of the closure. Alternatively, a single score could be provided which intersects theprimary score 20 at or near the apex of the tear strip and which extends outwardly to the skirt of the closure.Fitment 10 may further include a downwardly embossedcircular depression 26 in which atab 30 may be seated and a number of upwardly embossedarcuate ribs 28 onend wall 14 around its periphery to facilitate stacking containers on top of one another, and to protect the tab from accidental opening of the closure.

Pulltab 30, illustrative of the type of tab that may be employed, is attached to thetear strip 22 in its starting end by means of anintegral rivet 32.Pull tab 30 is a reverse acting, double-lever type having a centrallyopen ring body 34 with atongue 36 for affixation of therivet 32. Thetongue 36 is bendable at its junction with thetab body 34 so that the tab can be easily initially lifted from the surface of the fitment top for severance of thetear strip 22. As affixed to the tear strip, thetab 30 lies substantially flush with the surface of the bottom wall ofdepression 26, andribs 28 protect the opening structure from accidental opening or rupture of the score lines.

Aliner 38 may be provided within the fitment for effecting a seal when the assembly is affixed to acontainer 12, and may serve as a reclosure for the container after opening.Liner 38 may be formed from any of a variety of materials such as rubber, paper, cardboard, or a synthetic plastic such as polyethylene, polypropylene or polyvinyl chloride.Liner 38 has a complete spanning top portion including a recessedcentral panel 40 and a raisedrim 42 with askirt 44 depending therefrom, and is dimensioned to fit or nest inclosure fitment 10. An upwardlyopen groove 45 may be provided on the closure skirt for engagement offitment head 18 so that an assembly of the fitment and liner will not separate during handling prior to affixation to a container.

The container mouth entrance illustrated in FIGS. 3 and 6 is representative of a structure suitable for affixation of aclosure fitment 10 andliner 38. It will be observed thatcontainer 12 provides an entrance mouth defined by an outwardly projectingclosure securing head 46 having an upwardly facing sealing surface, a laterally facing side sealing surface and a shoulder having an undersurface blending into the container wall therebelow.

In the embodiment illustrated in FIGS. 1-6,tear strip 22 has an upwardly embossedrib 48 centrally located therein which extends from centrally in an essentially fiattop end wall 14 outwardly to a location adjacent the corner of the fitment between its end wall and skirt to structurally strength the tear strip during opening. As shown in FIG. 4,rib 48 has a generally arcuate transverse cross section, and extends outwardly at least to, and preferably beyond, a chordal line X-X drawn through the intersections of score line with the corner of the closure between theend wall 14 and the closure skirt 16 (FIG. 1).Rib 48 in combination with the curved arc of the closure skirt between the two legs ofscore 20 reinforcestear strip 22 to substantially eliminate bending of the tear strip between the end wall and skirt of the closure during opening.Bead 18 around the bottom edge of the closure skirt also helps to reinforcetear strip 22 and prevent bending of the tear strip during opening. By eliminating bending of the tear strip during opening,rib 48 greatly facilitates severance of the tear strip over the corner of the closure.

In prior art closures which had tear strips which were not reinforced against bending at the corner between the top end wall and skirt of the closures, the tear strips would sometimes bend at the corner of the closure during opening and this would subject the metal in the tear strip in the immediate area of severe bending to much higher than average bending stresses. Such excessively high localized bending tend to weaken the metal along the line of bending in the tear strip, so that when they are superimposed on top of the normal tensional stresses induced in the tear strip during opening the path of tearing may be directed inwardly of the score into the tear strip to cause premature severance of the tear strip. However, withrib 48 extending at least to chordal line X-X in a closure of the invention, bending of the tear strip 22at the corner of the closure is substantially avoided and the creation of excessively high localized bending stresses in the tear strip is substantially avoided. Tearstrip 22 may flex slightly during opening, but the central portion of tear strip remains substantially rigid against bending. By avoiding bending and excessively high localized bending stresses intear strip 22, premature severance of the tear strip is avoided.Metal fitment 10 is ruptured alongscore 20 as it desired rather than rupture the unscored metal in the tear strip between the score lines. Accordingly, severance oftear strip 22 will convertclosure fitment 10 into a partially split member which can be easily removed from a container as will be described.

To open a container having a closure of the invention affixed thereto, the free end of thepull tab 30 is lifted to fulcrum the tab about a point outwardly ofscore line 20, causingtongue 36 on the tab to bend or flex at its juncture with the tab body and exert an upward force onrivet 32 andtear strip 22. This causes initial rupture ofscore 20 around the attachment rivet at the starting end of, the tear strip. After initial rupture ofscore 20 around the starting end oftear strip 22, continued pulling oftab 30 ruptures the score along both sides of the tear strip into theclosure skirt 16. During such rupture,rib 48 reinforces the portion of the tear strip in which it is located and maintains the tear strip as a substantially rigid member as shown in FIG. 6, although it may flex slightly between thetop end wall 14 andskirt 16 of the closure. Initially,rib 48 may fulcrum or pivot about its outer end adjacent the corner of the closure as permitted by the resilience and slight flexing of the tear strip at such corner. However, the tear strip is quickly flexed to its maximum as limited byrib 48 and by the curved skirt portion in the tear strip, and the point of fulcruming moves to bead 18 on the bottom edge of the tear strip as illustrated in FIG. 6 to rupturescore 20 down the closure skirt. During such fulcruming of the rigid portion oftear strip 22, score 20 along both sides of the tear strip is subjected to an almost optimum combination of shear and tension which ensures that the tear strip is not prematurely severed from the closure at the corner between its top end wall'14 andskirt 16.

Astab 30 is pulled, tearing stops at the end of the short leg of scoring in the skirt of the closure, but continues along the length of the other leg of scoring which preferably extends all the way to the edge of the skirt throughbead 18 to convert the closure into a still unitary, partially split member with the tear strip attached to the skirt of the closure fitment by a ligament or bridge of metal between the end of the short leg of scoring and the bottom of the skirt. This results in confronting ends of the severed sectors of the closure fitment. Spreading such confronting ends will rupture at least one of thescores 24 adjacent the starting end of the tear strip and cause hinge-like opening of the closure without dismemberment thereof. The closure can then be lifted from thecontainer leaving liner 38 which can be removed with ones fingers.

Referring to FIGS. 7, 8, 9 and 10, an alternative embodiment of the invention is illustrated in the form of a sheetmetal closure fitment 50 which is adapted to be secured over the entrance mouth of acontainer 52.Closure fitment 50 is comprised of a spanning top portion or end wall with a recessedcentral panel 54, a raisedrim 56 around the central panel, and a dependingskirt 58 terminating in acircumferential bead 60.

Central panel 54 includes anincline 62 at its periphery which connectscentral panel 54 andrim 56.Closure fitment 50 is weakened or scored alongline 64 to define atear strip 66 divisive of the closure top from a starting location adjacent or towards the periphery of the top relative to its center, to a generally opposite location, and from there divisive of the closure fitment along one side of thetear strip 66 all the way to the edge of the sheet material of the fitment, and along the other side of the tear strip to a location short of the edge of the sheet material leaving a bridge or ligament of unscored metal between its end and the bottom of theskirt 58. Theclosure fitment 50 may also be scored outwardly of and adjacent to the starting end of thetear strip 66 by means of twoscores 68 which intersect theprimary score 64 on opposite sides of the apex of the tear strip, and extend from the primary score outwardly to the shoulder between therim 56 and theskirt 58 of the closure.

Apull tab 70 similar to the one that was shown on the closure illustrated in FIGS. 1-6 is attached to thetear strip 66 in its starting end by means of anintegral rivet 72.Pull tab 70 is a reverse acting, double-lever type having a centrallyopen ring body 74 with abendable tongue 76 for affixation of therivet 72. As affixed to the tear strip, thetab 70 lies substantially flush with the surface of the recessedpanel 54, and closure rim 56 protects thetab 76 and score 64 from accidental rupture.

Aliner 78 may also be provided withinfitment 50 for effecting a seal when the assembly is affixed to acontainer 52, and may also serve as a reclosure for the container after opening. It has a complete spanning top portion including a recessedcentral panel 80 and a raisedrim 82 with askirt 84 depending therefrom, and is dimensioned to fit or nest inclosure fitment 50. The bottom of theliner skirt 84 may include an upwardlyopen groove 85 for engagement ofcontainer bead 60 so that an assembly of the fitment and liner will not separate prior to application to a container.

The container mouth entrance illustrated in FIG. 8 is similar to that illustrated in FIG. 3, and is defined by an outwardly projectingclosure securing bead 86 having an upwardly facing sealing surface, a laterally facing side sealing surface, and a shoulder having an undersurface blending into the container wall therebelow.

In the embodiment shown in FIGS. 7-10,tear strip 66 has three upwardly embossed ribs in it which extend fromcentral panel 54 into raisedrim 56 around the central panel to structurally strengthen the tear strip during opening. The three ribs comprise acenter rib 88 extending from a central portion of the container end wall into the rim of container, and twoshort ribs 90, one of either side of thecenter rib 88, which also extend from the recessedcentral panel 54 into the rim of the closure. As shown, the twoshorter ribs 90 may diverge from thecenter rib 88 toward the periphery of the closure to form a rigid triangular-shaped zone in the closure. Referring to FIGS. 8 and 9,ribs 88 and 90 are inclined upwardly from the recessedcentral panel 54 to the area of therim 56 and have generally arcuate transverse cross sections as did the rib of FIG. 4.

All three ribs in thetear strip 66 preferably extend outwardly to, and preferably beyond, a chordal line X-X drawn through the intersections ofscore line 64 and the comer of the closure betweenrim 56 andskirt 58.. By extending theribs 88 and 90 at least to chordal line X-X, the ribs, in combination with the closure skirt, will reinforce the tear strip so that it can bend very little if any as it is severed over the rim of the closure. As a result, the creation of excessively high, localized bending stresses in the metal intear strip 66 is substantially avoided. This ensures that the metal in the fitment is ruptured alongscore lines 64 as is desired rather than rupture the unscored metal in the tear strip.Bead 60 around the bottom edge of the closure skirt also helps to reinforce the tear strip and ensures that the tear strip is not completely severed from the closure.

To open a container having a closure of the invention affixed thereto, the free end ofpull tab 70 is lifted to fulcrum the tab about a point outwardly ofscore line 64, causing tongue '76 on the tab to bend or flex at its juncture with the tab body, and exert an upward force onrivet 72 andtear strip 66. This causes initial rupture ofscore 64 around the attachment rivet at the starting end of the tear strip. After initial rupture ofscore 64, continued pulling oftab 70 ruptures score 64 along both sides of the tear strip into theclosure skirt 58. During such rupture,ribs 88 and 90 reinforce the portion of the tear strip in which they are located and maintain the tear strip as a substantially rigid member as shown in FIG. 6. This places thescore 64 along the sides oftear strip 26 in an almost optimum combination of shear and tension, and ensures that the tear strip is not prematurely severed from the closure atrim 56.

Astab 70 is pulled, tearing stops at the end of the short leg of scoring in the skirt of the closure, but continues along the length of the other leg of scoring which extends all the way to the edge of the skirt throughbead 20 to convert the closure into a still unitary, partially split member with the tear strip attached to the skirt of the closure fitment by a ligament or bridge of metal between the end of the short leg of scoring and the bottom of the skirt. This unitary, partially split member can then be removed from the container as was described with respect to the closure illustrated in FIGS. 1-6.

It will be apparent to those versed in the art to which the invention is addressed that particular embodiments have been selected for purposes of specific illustration and description, but that numerous variations can be made in the structural details of the selected embodiments without departing from the invention.

What is claimed is:

1. In a sheet metal closure having a top end wall and a depending skirt with a tear strip divisive of the top end wall and extending into the skirt, and further having a tab attached to the starting end of the tear strip, the improvement comprising at least one embossed rib in the tear strip extending from a central portion of the end wall outwardly at least to a chordal line drawn across the top of the closure through the intersections of the sides of the tear strip with the corner of the closure between its end wall and skirt to form a rigid section in the tear strip to resist bending thereof between the end wall and skirt of the closure whereby severance of the tear strip over the corner of the closure is facilitated.

2. A closure as set forth in claim 1 in which said rib is upwardly embossed.

3. A closure as set forth in claim 1 which includes a curled bead on the bottom edge of the closure skirt.

4. A closure as set forth in claim 1 in which said tear strip is defined by a U-shaped score having one leg which extends to the bottom edge of the closure skirt and a second leg which terminates short of the bottom wardly embossed ribs extending from the recessed central panel into the rim of the closure.

8. A closure as set forth in claim 7 in which said ribs extend outwardly at least to a chordal line drawn across the top of the closure through the intersections of the sides of the tear strip with the corner of the closure between its rim and skirt.

9. A closure as set forth in claim 7 including a center rib which extends from a central portion of the closure into the rim and two shorter ribs, one on either side of said center rib and diverging from the center rib as they extend toward the periphery of the closure.

Claims (9)

1. In a sheet metal closure having a top end wall and a depending skirt with a tear strip divisive of the top end wall and extending into the skirt, and further having a tab attached to the starting end of the tear strip, the improvement comprising at least one embossed rib in the tear strip extending from a central portion of the end wall outwardly at least to a chordal line drawn across the top of the closure through the intersections of the sides of the tear strip with the corner of the closure between its end wall and skirt to form a rigid section in the tear strip to resist bending thereof between the end wall and skirt of the closure whereby severance of the tear strip over the corner of the closure is facilitated.

2. A closure as set forth in claim 1 in which said rib is upwardly embossed.

3. A closure as set forth in claim 1 which includes a curled bead on the bottom edge of the closure skirt.

4. A closure as set forth in claim 1 in which said tear strip is defined by a U-shaped score having one leg which extends to the bottom edge of the closure skirt and a second leg which terminates short of the bottom of the skirt.

5. A closure as set forth in claim 1 in which said top end wall is substantially flat and said rib is substantially equidistant between the sides of the tear strip.

6. A closure as set forth in claim 5 in which said top end wall includes a circular depression in which said tab is seated.

7. A closure as set forth in claim 1 in which said top end wall includes a recessed central panel with a raised rim therearound and the tear strip includes three upwardly embossed ribs extending from the recessed central panel into the rim of the closure.

8. A closure as set forth in claim 7 in which said ribs extend outwardly at least to a chordal line drawn across the top of the closure through the intersections of the sides of the tear strip with the corner of the closure between its rim and skirt.

9. A closure as set forth in claim 7 including a center rib which extends from a central portion of the closure into the rim and two shorter ribs, one on either side of said center rib and diverging from the center rib as they extend toward the periphery of the closure.

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