CA2851191C - Reduced gauge bottle cap - Google Patents

Abstract

A reduced gauged crown for a container opening includes a corrugated panel portion such that the corrugation strengthens the crown material and allows less material to be used for the crown than would be used for an uncorrugated bottle cap.

Description

REDUCED GAUGE BOTTLE CAP
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001]
FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to caps and crowns: for beverage bottles and other containers, and in particular, to a reduced gauge corrugated bottle cap.
BACKGROUND

[0003] Published US patent application ser. No.
12/597,385(U.S. Publication No. 2010-0326949 Al) to Merino Caballero ("Caballero") discloses a low gauge crown cap in which the top panel exhibits grooves in various shapes, depending co the embodiment, to achieve corrugation and obtain a crown that hap a low gauge of crown material such as steel. Although not prior art due a priority date subsequent to the priority date of the present disclosure, the present inventor acknowledges the Caballero application because it was published prior to the filing date of the present disclosure.

[0004] Related application serial number 12/903,533 (U.S.
Publication No. 2011-0024381 Al), and its parent 11/698,247 (U.S Publication No. 2007-0181526 Al which issued as US patent no. 8,061,544), referenced above, disclose a bottle crown that has a seat in which rests a pull tab assembly so that the pull tab assembly is flush with the top of the crown. The seat is formed by means of a depression or recess in the top of the crown. A benefit of the recessed top is that the recess functionally acts to corrugate the top of the crown. As is well understood, corrugation has the advantage of stiffening a sheet of material against forces that are perpendicular to the direction of corrugation. That is, a corrugated sheet is harder to pend than a non-corrugated sheet, at least in , certain. directions. A bottle crown that has corrugation across its top will. be stiffer than a non-corrugated crown.
therefore, to achieve the same degree of stiffness of a non-corrugated crown, a corrugated crown may be thinner, or nave a lower gauge, of crown material such as steel or tinplate.
The advantages of corrugation that are implicitly inherent in the crown of tte 1533 application are made explicit in the present disclosure. The present da;sc1051re4 therefore, deStl'qbes a corrugated. oroWn and the advantages- thereof.
BRIEF DESCRIPTION OP THE DRAWINGS

(0005] The .detalled description that follows, by way of nOn-limiting examples of embodiments, makes reference to the .noted d.raw ns in which. reference- nutherals represent the same parts throughout the several views of the drawings, and in which:
100601 Figure is an iackietric side view illustration of a reduced gauge crown of the preSett mention.
100073 Figure 2A is a top view illustration of the crown of rig- 1.
10008] Figure al: is a side cross-section view c fthe cmoTgla of Fig. 2A.
10-0091 Fi4ute 3A is a top view illustration of an alternative embodiment of a crown of the present dfsclosure.
(0010] Figure 33 is a side cross-section view of the crown Of Fig. 3A.
100113 Figure 4A is a top view illustration of another alternative embodiment of a crown of the. present disclosure.

0 0 12] Figure 4B is a side cross-section view- of the -crown of lig. 4Aõ
Detailed Description of Exemplary Embodiments f0013] Figure 1 is. an isometric: side view illustration of a reduced qauga crown ,of the present. invention. Crown 100 includes top portion 110 contiguoUs with retesS .120 which terminates .panel 130.
Skirt 140 downwardly extends. from top 120. rn same specific embodiments a flange extends obliquely- from skirt 140. Alternating flutes 150 and lands 152 are formed on a circumferential portion of skirt 140. Crown 100, and other .crowns i shown in the figures, is shown pry-off type that is opened with a lever, The Vreset invention also encompasses a tit-of! type (not shown in. the figures) that is opened by twisting, as will be understood by persons familiar with crown Cap technology. FInally, Crown 100 is suitable for use with pull tab type aes.emblies mamited to panel 130 with effective- score lines embossed on on crown 100.
POW Panel 130 is recesst:Ri, that is, it .is lower thsn top 110 but is contiguous with top 110 by virtue of transition surface I20i which will be referred to herein for convenience as. recess 120. Recess 120 may formed in crown 100 in a variety of suitable way to provide advantageous shapes. For example, in specific exemplary embodiments- concentric tiers, grooves .0t- steps are integrally formed in the crown 1-00 material until the desired depth dr. Panel 130 is obtained, as illustrated in Fig. 1- In alternative ambOdiments, recess 120 is formed with a smoothly curved. surface. from top 110- to panel 130.
The 6orM of. recess 12( functions as ribs or structural reinforcements that, it is surmised, help. to stiffen panel 1.30 against -deflection- or deformation-mist Skirt 140- -descends frOm top 110 along the external perimeter of crown 100 and in specific exemplary embodiments smoothly merges into downwardly and radially outwardly extending flange. The skirt 140 is preferably adapted to be crimped onto the neck of a bottle for sealing. Specific exemplary embodiments of skirt 140 are divided into undulating, repeating portions that define the flutes 150 and lands 152. Preferably, the repeating portions are citowilferentially evenly spaced apart such that eath tiutAt 150 is ideptical to all other flutes 150 around tte circumference of the crown cap 100, and each land 152 is identical tO-all. other lands 152 atoOnd. 'the circumference. of the crown cap 100.. It should be understood that the crown cap 100 may include any number of flutes 150 and lands 152.
t00161 Referring to now to Figs 2A and 2114. ap, and 38 and 4.A and 413, the "B" fiaure of each depicted. embodiment is the horizontal cross section of its "A" counterpart

6 througll. U:rie "5-B, Echembodiment, designated 2A/B, 3A/B
and 4A/B, is characreri2ed by a particular diameter of Ats pan4l 130i, as represented by width 13 210.; 310-and 41fl.
of each embodiment, respeCtively, and depth A of recess 120 represented by depths 220, 320- and 420, respectively.
100173 A specific- amolInt of material strengthening from corrugation is achieved by aelecting an embodiment, with a particular combination of panel diameter 210, 310 -nr 410, for example, and -recese depth. 220, 320 Or 420, for example-. Exemplary embodiment 2A/B, for instance, has panel diameter 210, Which is relative Wide, and recess depth 220, which is intermediately deep. Exemplary embodiment 3A/B has panel width 310, which of intermediate width, and recess depth 520, which is the deepest of the. three. exemplary embodiments. Exemplary embodiment 4A/B- has panel diameter 410, which is the narrowest of the embodiments, and r3ecess depth 420, which is the shallowest depth of the three eMbodiments.
To obtain a desired- ammint of material strengthendng from corrugatiOn, a- combination of panel width 21.1), 310, or 410, for akample, and recess depth 220, 320 or 420, for example, iB selected to achieve a specific embodiment.
100181 Corrugation strengthens materials. This is partioolarly true. tyt laminar materials formed into a sheet or plane. A laminar product can use les$ of a material if the material is corrugated to provide lateral

7 strengt11,, A bottle Zap is a :laminar produZt in which the sheet msterial, often steel or tin plate, is shaped to be affil(ed to the too ot a bottle Or Other centainer. A
standard pry-off or twist Off cap has a thickness of that is predominantly determined by oonSideratiOns of 'leak prevention and the secureness pf the attachment of the zap to the: container.
[0019] Billions Of bottle Caps are used Wofidwide end the coS-t pr the Caps iS largely dermined by the amount of material requited for the caps. Corrugation allows caps that use leaa material to have the equivalent strength of a standard thick crown. A corrugated crown is thinner, that is, it has a reduced gauge, in comparison to a standard bottle cap. An advantage of a reduced gauge Cap= is the money savings obtained by using less material.
100201 Another advantage of 4 reduced gauge corrugated cap conies into play with innovated "pull-off" caps-, which have d pulL tab astembly attached to the crown as described it the related patent applications. The Tull tab breaks the cap material And the crown iS torn off the bottle using the pUli tab. A reduced gauge cap facilitates the teat off because the cap material is thin and the tearing action is parallel to the: direction of material strengthening provided by the corrugation and therefor the tearing force does not have to overcome the material strengthening of the corrugation. Corrugation

8 affords material strengthening. perpendicular to the direction cf corrugation.
100211 In addition to the structures illustrated in the figures herein, it is understood that other structures will imbue a cap of the present diSolosure with the advantages of corrugatoh and provide a reduced gauge crown for a bottle.. For Instance, concentric rings, which progress from the top of the skirt toward the center of the panel, and decorative. shapes such as stars, brand logos, sports team logos, religious insignia, and the like, formed in the plane of the cap, are embraced in the present disclosure. [0022] Corrugation forms may be provided to a bottle tap by a variety means, including without limitation, metal stamping, pressing, embossing and: so forth. Non-metal crowns of the present disclosure may be formed by injection- molding for plastic_crowns, or by other suitable means of production.
(0023] The crown caps 100 preferably ate formed with steel of increased: hardneas compared. with conventional crown caps presently in. commercial production. For example, conventional crown caps are often formed Of single redUced, T4, tinplate having A thickness of from 0.21 mm. to 0.23 mM. Such tinplate has an average hardness (that is4. the eparted hardness value regardless of +i variations) of Approximately 61 on a 3057 hardness scale, in accordance with ASTM 623. Crown caps 100 described

9 herein may be made thinner and lighter weight compared with the prior art, for example, crown caps 100 may be.
fOrmed Of A Materiai having a thickness Or about 0.16 mm to 0.18 mm that have the same or roughly equal p0Olormance as T;:onventional, thicker caps. These decreases in metal usage. are more eaally achieved- wbon the structure of crown caps 10 are made.. with steel. having increased hardness. For examplei the. inventor has demonstrated. the effectiVeness of low gauge crowns having grooves using DR8- ..according to AT -623) or DR550 (according- to EN 10-203. , Optionally, the- inventor surmises that other materials may be used, such as single reduced tinplate or like material having enhance tempering., tin-free steel having similar properties as those described herein, and the like.
00243 The crown- caps 100 preferably have an average hardness of greater than 62 on the 30T scale (conforming to ASTM 25)-, More preferably greater than about 65, more preferably greater than about 68 more preferably greater than about 71,. The embodiments shown in rIG. 1 and FIG.
3A were. 40monStrated to be effective Using steel having a hardness of 73. The upper limit of hardness is set by the maximum stress acceptable to the glasa bottle during the crimping process or the spring back (which may tend to urge the crimped flanges toward an: uncrimped state) associated with harder plate, 10025) The- croWn. caps 100 :slay be Eermed with conventional press eguipment, with only -minor changes to parts of the tOoling to for the structure (such. As the grooves, crosses,- stars, and dimples) : And crown. Caps 109 may be crimped with conventional eguipment only modified. to have a. smaller throat coMpared. with existing, conventional crimpers, 09261 Because hardness has. a. relationship to strength.as reflected in the point, the aspect of the. hardness of the crown may be expressed in yield point on a correspondinq scale. For example, DR 8 or DR550 tinplate may has- a yield point (in a. tensile: test) of 550 MPA. The inventor believes that the most advantageous crown cap has a combination of one- or more of the structured described herein and harder plate as 4escribd herein- A
crown of the present disclosure, however, encompasses orown caps that do not have ail of the structures materials, and/or advantages in this specification.
100271 -According to this description, comercially acceptable crown- caps forMed according to the present disclosure can be commercially made with up to 25 percent less steel compared With many conventional crown caps, which has corresponding- advantages in carbon emissions.
The savings- in steel weight. are approximately proportionate to the reduction in metal thickness.
Further, even though energy required to cool an individnal crown is tiny, the energy required to cool the total number of crowns produced each year (approximately 45 billion it Nerth America And approximately 300 billion throughout the worldY, and the corresponding reduction in ..hat energy is sign/flea-a, [0028] In addition to the various structures described herein, certain Advantages over the prior art are beetoWed on the present cron by the recomMended specifications shown in Table 1.

Items' Acceptable Ranoe 1 Taraet 1. Appearance DisC properly adhering White :liner Complete liner -Cleat liner 'Clean crown and ring No rust and scratch for crown and ring Two cut lines on the downward surface of Crown Rivet Crown 2. Dims ions Thickne :(03): 0..24-0.28 1.nicie diameter .mm): 32.08 32.12 Outside diameter (mm); 2'6.60 - 20.90 Radius o:f angle (mm) t! 1,9 Number of angels': 21 no DiaMetet (11110 21,1 - 21.5 Thickness fmmI: 0-.28 ¨ 0.32 Liner 'Diameter Om0.:: 20.00 3. Rockwell Hardness T4-on. the Rockwell 30T scale 4.- Secure Seal Greater than/equal to 150 PSI
for 1 minute 5. Finish Verdness Should not scratch with "H"
pencil 6. Sensory No significant differences with an identified control after 12 weeks at 20 degrees C.
7. Lubricant Migration No particles Or lubricant should be present:
imulated. Palletizing. CO2 loss should not differ against control caps when stored for 1 week with max weight of 45 Egs over each bottle 9. Corrosion Maximum corrosion:. slight to moderate

10. Odor No off odors detected

11. ?uliin4 Force of Ring (kg) 2.5kg

12. Composition of Material Tinplate crown and ring; food class non-PVC for liner

13. Package 5000 Crowns per box

14. Pressure. (kg) 10kg 22,, Container Loading 1,000 Master Carton*
16. Printing Logo/other design may be printed on the. Easy Pulio Cap 17. Crown. Anti-Oxidation Material. used is 'food grader' PET; clear, with no. odor, 1.2 UM (micrometers) [0029] In particular, a tinplate Material which demonstrates an approximate hardness of T-4 on the Rockwell 30T Hardness Scale is preferred for. the present cap (sea item 1 IA table 1), Tht$ may be contrasted against the prior art Which typically uses tinplate having a hai:dne:7,14 of rõ---3- On the Rockwell scale. The preferred softer tinplate material requires less force to open and tear with the opener assembly of the present crown while still providing sutficient sealing of the cohtents. For the purposesof this disclosure, tinplate refers the any material, including tin or tin , alloys, from which a Crown May be fabricated and does not necessarily mean that the crown is made from:. tip or a tin 00301 The foregoing description IS provided for the purpose Of :explanation and.. is not to be: construed as limiting the invention. While the invention has been destribed 4ith reference to preferred embodiments or preferred methods, it is understood that the words which have been used herein are words of deSoription and rather than words Of limitation.
Furthermore, although the invention has been described herein with reference to particular structure, methods, and embodiments, the invention is not intended to be liMited to the partiOulars disclosed herein, as the invention extends to ail structures, methods and uses that are within the scope of the appended claims. Those skilled in the relevant Art, having the benefit of the teachings of this specification, may effect numerous modifications to the invention as described herein, and :i.ianges may be made without departing from the scope and spirit of the invention as defined by the appended claims. Furthermore, any features of one described embodiment can be applicable to the other- eMbodiments described herein.
Such: embodiments of the inventive subject matter may be referred to he.r.in, 4.1101,vidua¶y and/or colleOtively, by the tetM 'invention merely for 66nvenienbe and without intending to volUntarily limit the scope of this application to any single inVention or inventive. concept if more than one is in fact disclosed.
Thus, although specific embodiments- have been illbstrated and described herein, it should be appreciated that any amranOement calculated to achieve the same purpose may be substituted for the specific embodiPents shown. This disclosure is intended to cover any and all adaptations or variations of various emboditents. Combinations cf the above embodiments nd other embodiments not specifically described herein, will be apparent to those of skill in the. art upon- reviewing the above description.
[00.321 In summary, the present disclosure describes. a =1 for a container opening. The Crown has a top prtion and an inner portion contiguous with the top portion.. The inner is portion formed into a panel. An outer portion contiguous with the top portion is formed into a skirt that descends from the top portion. The crown has corrugation formed- in the panel,

15 [0033] The present disclosure also contemplates methods tor mating the crown described above. Methods include the steps of shaping a sheet of crown material to provide a top portion and an inner portion contiguous with the top portion and formed into a panel. An outer portion contiguous with the top portion is formed into a skirt that descends from the top portion. The methods also include forming corrugation in the panel.
[0034] In specific embodiments the stop of forming corrugation in the panel consists of forming a recess that descends from the top portion to the panel, in the inner por Lion.
[0035] In addition, in the foregoing Detailed Description, it can be seen that various features, are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

16 [0036] The description, has made reference to several exemplary embodiments. It is understood, however, that the words that have been used are words of description and illustration, rather than words of limitation. Although description makes reference to particular means, materials and embodiments, the disclosure is not intended to be limited to the particulars disclosed; rather, the disclosure extends to all functionally equivalent technologies, structures, methods and uses such as are within the scope of the appended claims.

Claims (9)

Claims

1. A crown for a container, the crown comprising:
a top portion, an inner portion contiguous with the top portion, an outer portion contiguous with the top portion, the outer portion formed into an annular skirt that descends from the top portion, CHARACTERIZED IN THAT:
the inner portion comprises corrugation comprising a recessed panel formed in the top portion of the crown to a desired depth; and the crown has a thickness gauge in the range of 0.16mm to 0.18mm, and the crown comprises material having an average hardness of greater than 62 on a 30T
hardness scale;
wherein the recessed panel comprises a uniform thickness across its entirety and is positioned such that a top surface of the recessed panel is below a bottom surface of the top portion by an amount greater than the thickness of the recessed panel, the corrugation formed in the top portion sufficient to provide reinforcement to stiffen the inner portion against deflection by providing material strengthening perpendicular to the corrugation.

2. The crown of claim 1, wherein the corrugation comprises transition portions contiguously formed from the top portion to the recessed panel.

3. The crown of the claim 2, wherein the corrugation comprises one or more shapes formed in the recess.

4. The crown of claim 1, wherein the recessed panel comprises a single surface parallel with a top surface of the top portion of the crown.

5. The crown of claim 1, wherein the corrugation comprises concentric rings formed in the top portion to the recessed panel at descending depths that progress from the skirt toward a center of the crown.

6. A method for making a crown for a container, the method comprising:

shaping a sheet of crown material to provide a top portion, an inner portion contiguous with the top portion, and an outer portion contiguous with the top portion and formed into an annular skirt that descends from the top portion;
CHARACTERIZED IN THAT the crown has a thickness gauge in the range of 0.16mm to 0.18mm, and the crown comprises a material having an average hardness of greater than 62 on a 30T hardness scale, and that the method further comprises:
forming the inner portion to include corrugation comprising a recessed panel formed in the top portion of the crown to a desired depth, wherein the recessed panel comprises a uniform thickness across its entirety and is positioned such that a top surface of the recessed panel is below a bottom surface of the top portion by an amount greater than the thickness of the recessed panel; and wherein the corrugation formed in the inner portion is sufficient to provide reinforcement to stiffen the inner portion against deflection by providing material strengthening perpendicular to the corrugation.

7. The method of claim 6, wherein the step of forming the inner portion to include corrugation consists of forming transition portions contiguously formed from the top portion to the recessed panel.

8. The method of claim 6, wherein the recessed panel comprises a single surface parallel with a top surface of the top portion of the crown.

9. The method of claim 6, wherein the corrugation comprises concentric rings formed in the top portion to the recessed panel at descending depths that progress from the skirt toward a center of the crown.