US3715052A - Full panel self-opening end closure - Google Patents

Full panel self-opening end closure Download PDF

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Publication number
US3715052A
US3715052A US00196670A US3715052DA US3715052A US 3715052 A US3715052 A US 3715052A US 00196670 A US00196670 A US 00196670A US 3715052D A US3715052D A US 3715052DA US 3715052 A US3715052 A US 3715052A
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US
United States
Prior art keywords
score
rupturable
end closure
steel
residual
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00196670A
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English (en)
Inventor
C Kinkel
T Phalin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rexam Beverage Can Co
Original Assignee
American Can Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by American Can Co filed Critical American Can Co
Application granted granted Critical
Publication of US3715052A publication Critical patent/US3715052A/en
Assigned to AMERICAN NATIONAL CAN COMPANY reassignment AMERICAN NATIONAL CAN COMPANY MERGER (SEE DOCUMENT FOR DETAILS). Assignors: AMERICAN CAN PACKAGING INC., NATIONAL CAN CORPORATION (CHANGED TO), TRAFALGAR INDUSTRIES, INC. (MERGED INTO)
Assigned to AMERICAN CAN PACKAGING INC. reassignment AMERICAN CAN PACKAGING INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AMERICAN CAN COMPANY, A NJ CORP.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D17/00—Rigid or semi-rigid containers specially constructed to be opened by cutting or piercing, or by tearing of frangible members or portions
    • B65D17/28—Rigid or semi-rigid containers specially constructed to be opened by cutting or piercing, or by tearing of frangible members or portions at lines or points of weakness
    • B65D17/404—Details of the lines of weakness

Definitions

  • the rupturable score is formed near the periphery of the central panel to define a large removable portion within the central panel, and the non-rupturab1e score is disposed closely adjacent to but radially inwardly of the rupturable score.
  • the present invention broadly relates to improved self-opening or easy opening end closures for containers, and is more particularly concerned with the combination of a rupturable score and a non-rupturable score both being formed in the interior, or productfacing, surface of an end closure made of tin-free steel or tin-plated steel sheet metal.
  • end closures of the self-opening variety each having a rupturable score which defines a remova- 'ble panel portion within the end closure, have predominately been made of aluminum rather than of steel.
  • Aluminum has been preferred over steel because it has less tendency to work harden and it has much lower tear strength than steel. Because of less work hardening which results in lower scoring forces aluminum causes less long-term wear in scoring dies, in commercial operation.
  • the comparative weakness of aluminum permits a broader range of residual metal thicknesses for the rupturable score while insuring satisfactory performance of the scored aluminum end closure from the standpoint of ease of opening.
  • US. Pat. No. 3,543,961 discloses a full panel, self-opening steel end closure wherein a single rupturable score defining the removable portion is formed in the interior surface of the end closure at the juncture between the central panel and the annular, seam-defin ing peripheral portion of the steel end closure
  • US. Pat. No. 3,527,377 discloses a full panel, selfopening steel end closure wherein a single rupturable score defining the removable portion is formed in the exterior surface of the end closure adjacent to the periphery of the central panel.
  • the combination of a peripheral rupturable score and a closely associated non-rupturable or anti-fracture score both being formed in the exterior surface of an end closure is disclosed in US. Pat. No. 3,406,866, and U.S. Defensive Publication Ser. No. 793,231.
  • the range of residual steel metal thicknesses for any rupturable score must be wide enough to allow for the variations in the depth of scoring which will normally be experienced in any high speed commercial manufacturing operation, such variations being caused by inherent limitations on the precision of scoring tools and by long-term wear of scoring dies, which is an especially critical problem in the scoring of steel metal.
  • Manufacturing experience has shown that a range of score residual thicknesses of approximately 0.001 inch or greater is required for the high speed commercial scoring of steel sheet metal.
  • the residual metal of any rupturable score must meet the acceptable commercial standards of score integrity and ease of opening, as well as the manufacturing requirements imposed by the high speed commercial scoring operation. These two characteristics, integrity and ease of opening (also referred to as openability), of the score are both greatly influenced by the residual metal thickness of the score. This is particularly true when the score is formed in steel sheet metal.
  • score residual integrity mainly refers to the structural quality of this residual steel metal.
  • the thinner the residual metal thickness the greater the likelihood that microfractures or minute cracks will be propagated through the residual steel metal by the scoring operation and the greater the likelihood that the thin residual metal will be prematurely and inadvertently fractured by the normal abuse which the end closure will subsequently receive during the packing, shipping and other handling required of the container incorporating the end closure before the container reaches the consumer. Therefore, the minimum value of the range of the residual score metal thicknesses must be the minimum residual thickness to which the steel metal can be scored without introducing microfracture defects which are detrimental to the integrity or abuse resistance of the score.
  • the maximum value of' the range of score residual steel metal thicknesses will be determined by the maximum amount of work that a consumer can be expected to expend in opening the end closure. For example, in the case ofa 2 1 l/16th inch diameter steel end closure, experience has shown that the maximum amount of work that a consumer can be expected to expend in opening the full panel end closure without finding the opening operation objectionable or unpracticable is approximately 18 inch-pounds, as measured on an Instron tensile tester.
  • an operating residual thickness range of from approximately 0.0024 to 0.0036 inch is preferable in that it assures acceptable ease of opening and integrity of the rupturable score residual and provides sufficient latitude for the commercial scoring operation, and this range, which is included in the 0.0019 to 0.0036 inch range given above, is easily obtained with this construction.
  • the preferred residual score metal thickness is thus 0.0030 inch with a plus or minus 0.0006 inch variation in the residual score thickness being acceptable.
  • the present invention relates to the combination of a rupturable score and a shallower, non-rupturable score formed in the interior surface of a generally flat central end panel of a self-opening end closure made of a steel basis sheet metal.
  • the rupturable score is formed near the periphery of the central end panel to define a large removable portion within the end panel.
  • the non-rup turable score is formed adjacent to the periphery of the removable portion of the central end panel inwardly from, and substantially concentric with, the rupturable score.
  • the thickness of the residual steel sheet metal of the non-rupturable score is substantially greater than that of the rupturable score.
  • Both scores have a generally trapezoidal cross-sectional profile.
  • the residual steel metal thickness of the rupturable score may vary within the range of from approximately 0.00l9 to 0.0036 inch, and, preferably, from 0.0024 to 0.0036 inch which insures a high speed commercial manufacturing capability, while still maintaining satisfactory performance of the steel end closure from the stand-point of score residual integrity and openability.
  • FIG. 1 is a plan view of the interior surface of a full panel, self-opening steel end closure having formed therein the peripheral, rupturable score and closelypositioned, shallower, non-rupturable score;
  • FIG. 2 is a plan view of the exterior surface of the full panel, self-opening steel end closure of FIG. 1;
  • FIG. 3 is an enlarged fragmentary sectional view of the double score combination taken substantially along line 3-3 of FIG. 2.
  • FIGS. 1 and 2 A full panel, self-opening end closure, generally designated 10, embodying the instant invention is shown in FIGS. 1 and 2.
  • the self-opening end closure is made of a steel basis sheet metal which may be either tin-free steel or tin-plated steel, and, preferably, has a circular configuration.
  • the steel sheet metal of the end closure 10 has a thickness within the range of from approximately 0.006 to 0.012 inch, and, preferably within the range of from approximately 0.007 to 0.009 inch.
  • the self-opening end closure 10 includes a peripheral outwardly extending annular curled flange 12 which may be interfolded with an end flange of a container body (not shown) to form an end seam (not shown).
  • the peripheral flange 12 merges into an annular countersink wall 14 which extends downwardly from the peripheral flange 12 to an imperforate central end panel 16.
  • a rupturable score 18 and a nonrupturable score 20 are formed in the interior surface 22 of the central end panel 16.
  • the radially outer rupturable score 18 is positioned adjacent to the periphery of the central end panel 16 to define a large removable portion 24 within the central panel 16 which becomes detached from the end closure 10 when the score 18 is completely ruptured.
  • the radially inner non-rupturable score 20 is positioned adjacent to the periphery of the removable portion 24 inwardly from, and preferably substantially concentric with, the rupturable score 18.
  • the non-rupturable residual steel metal section 26 of the non-rupturable score 20 has a substantially greater thickness than the rupturable residual steel metal section 28 of the rupturable score 18, the differential in the thicknesses preferably being approximately 0.0025 inch.
  • the center-to-center spacing between the rupturable score 18 and the non-rupturable score 20 is preferably approximately 0.060 inch.
  • the non-rupturable score 20 functions to protect the rupturable score 18 from premature, inadvertent rupture in the manner described in U. S. Pat. No. 3,406,866 herei nbefore mentioned.
  • the thickness of the rupturable residual steel metal section 28 of the rupturable score 18 ranges from approximately 0.0019 to 0.0036 inch, which permits satisfactory performance of the steel end closure from the standpoint of score residual integrity and openability and provides sufficient latitude for the commercial scoring operation. Actually, an operating residual thickness range of from approximately 0.0024 to 0.0036 inch is preferable in that it assures acceptable ease of opening and integrity of the rupturable score residual section 28' while still providing sufficient latitude for the commercial scoring operation.
  • the thickness of the rupturable residual steel metal section 28 of the rupturable score 18 is preferably approximately 0.0030 inch.
  • the thickness of the non-rupturable residual steel metal section 26 of the non-rupturable score 20 may vary within a range comparable to that of the rupturable residual steel metal section 28 of the rupturable score 18 so that the differential in the thicknesses of the respective residual metal sections 26, 28 will be maintained at approximately 0.0025 inch.
  • an opening tab 30 is fastened to the removable portion 24 on the exterior surface 32 of the central end panel 16 at a location ad- 5 jacent to the exterior surface 34 of the rupturable residual steel metal section 28 of the rupturable score 18 by a hollow rivet 36.
  • the rivet 36 is integral with the removable portion 24 and has a peripheral portion 38 which overlies and bears down on the opening tab 30 to secure it on the removable portion 24.
  • the opening tab 30 has a handle portion 40 into which the finger of a user may be inserted and a nose portion 42 which will be urged downwardly into contact against the exterior surface 34 of the rupturable residual steel metal section 28 of the rupturable score 18 when the user raises the handle portion 40 of the opening tab 30 to initiate pop or rupture of the rupturable score residual steel metal section 28.
  • both the rupturable score 18 and the non-rupturable score 20 preferably have a generally trapezoidal cross-sectional profile.
  • the rupturable score 18 includes two steeply inclined, and oppositely disposed, side walls 44 which convergently extend from the interior surface 22 of the central end panel 16, and a substantially flat base wall 46 which is in a plane generally parallel to the interior surface 22 of the central end panel 16 andmeets the side walls 44 preferably at generally sharp corners of intersection 48. Alternatively, the corners of intersection 48 could be arcuate-shaped instead of being sharp.
  • the base wall 46 preferably has a width within the range of 0.0015 to 0.0035 inch.
  • the non-rupturable score 20 has substantially the same structural features as" the rupturable score 18 except for the above-described substantial difference between the thickness of the non-rupturable residual steel metalsection 26 and the thickness of the rupturable residual steel metal section 28.
  • the rupturable score 18 in being formed in the interior surface 22 of the central end panel 16 acts as a notch which concentrates stresses applied when completely opening or rupturing of the rupturable residual steel metal.
  • section 28 by means of pulling the opening at a substantially greater score residual metal thickness than attainable with the exterior rupturable score where the stresses are spread over a larger area of the interior surface of the residual section opposite to the outside rupturable score.
  • the end closure 10 of the present invention is made of a steel basis sheet metal, such as tin-free steel or tinplated steel.
  • the substrate of steel sheet metal has a layer of tin on the steel surface which is to become the interior surface of the end closure.
  • the substrate of steel sheet metal has a layer of tin on the steel surface which is to become the exterior surface of the end closure.
  • Each of the tin layers may have a weight within the range of approximately 0.25 pound/base box to 1.35 pound/base box.
  • the tin layer on the interior surface of the steel sheet metal has a weight of approximately 0.75 pound/base box
  • the tin layer on the exterior surface of the steel sheet metal has a weight of approximately 0.25 pound/base box.
  • the tin layers respectively preferably have nonmetallic protective coatings applied thereon.
  • the protective coatings are preferably applied to respective tin layers when the steel metal is in the web form before the blank has been punched from the web of steel material.
  • the protective coatings may be applied to the tin layers by any suitable process of application, for example, by a conventional rolling or spraying process.
  • the double score combination of the end closure 10 is formed by a conventional double scoring tool which is impressed into the central end panel 16 while the end closure 10 is supported on a suitable anvil.
  • the double scoring tool preferably has a cross-sectional profile which is substantially complementary to the desired profiles of the double scores.
  • a rupturable score formed in the interior surface of a central end panel of the end closure adjacent to, and radially inwardly from, the periphery of said end panel to define a removable portion within said end panel, said rupturable score having a generally tra ezoidal cross-sectional profile; and a non-rupturab e score formed in the in error surface from the standpoint of score residual integrity and openability.
  • the combination according to claim 1 wherein the thickness of the residual steel metal of said rupturable score preferably ranges from approximately 0.0024 to 0.0036 inch, which permits satisfactory performance of the steel end closure from the standpoint of score residual integrity and openability.
  • the com- 1 bination according to claim 1 wherein the thickness of the residual steel metal of said rupturable score is preferably approximately 0.0030 inch, which permits satisfactory performance of the steel end closure from the standpoint of score residual integrity and openability.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Containers Opened By Tearing Frangible Portions (AREA)
  • Closures For Containers (AREA)
US00196670A 1971-11-08 1971-11-08 Full panel self-opening end closure Expired - Lifetime US3715052A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US19667071A 1971-11-08 1971-11-08

Publications (1)

Publication Number Publication Date
US3715052A true US3715052A (en) 1973-02-06

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ID=22726352

Family Applications (1)

Application Number Title Priority Date Filing Date
US00196670A Expired - Lifetime US3715052A (en) 1971-11-08 1971-11-08 Full panel self-opening end closure

Country Status (7)

Country Link
US (1) US3715052A (cs)
JP (1) JPS572277Y2 (cs)
CA (1) CA964604A (cs)
CH (1) CH557266A (cs)
FR (1) FR2159335B1 (cs)
GB (1) GB1403037A (cs)
IT (1) IT972393B (cs)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946683A (en) * 1972-12-26 1976-03-30 Aluminum Company Of America Tabless container opening device and method and tools for forming the same
US4890130A (en) * 1986-10-17 1989-12-26 Fuji Photo Film Co., Ltd. Lens-fitted photographic film package
EP0693429A2 (en) 1994-07-22 1996-01-24 Rheem Empreendimentos Industriais E Comerciais S/A Can body anti-cut protection and process for obtaining a can body with anti-cut protection
US6447176B2 (en) 1999-03-05 2002-09-10 West Bend Film Company, Llc Film canister device for use in a film package assembly and a method for loading a camera therewith and a camera loadable thereby

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3891116A (en) * 1972-12-14 1975-06-24 American Can Co Full-open easy-open container
DE2727737C2 (de) * 1977-06-21 1982-07-29 Franz Pohl, Metall- und Kunststoffwarenfabrik GmbH, 7500 Karlsruhe Bördelkapsel

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3501046A (en) * 1968-08-02 1970-03-17 Continental Can Co Pull tab configuration
US3576272A (en) * 1969-06-30 1971-04-27 Procter & Gamble Score-line structure

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3248003A (en) * 1961-05-29 1966-04-26 Continental Can Co Easy opening tapered can
US3272166A (en) * 1964-05-07 1966-09-13 Continental Can Co Method of assembling a pull element and a can end

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3501046A (en) * 1968-08-02 1970-03-17 Continental Can Co Pull tab configuration
US3576272A (en) * 1969-06-30 1971-04-27 Procter & Gamble Score-line structure

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946683A (en) * 1972-12-26 1976-03-30 Aluminum Company Of America Tabless container opening device and method and tools for forming the same
US4890130A (en) * 1986-10-17 1989-12-26 Fuji Photo Film Co., Ltd. Lens-fitted photographic film package
EP0693429A2 (en) 1994-07-22 1996-01-24 Rheem Empreendimentos Industriais E Comerciais S/A Can body anti-cut protection and process for obtaining a can body with anti-cut protection
US6447176B2 (en) 1999-03-05 2002-09-10 West Bend Film Company, Llc Film canister device for use in a film package assembly and a method for loading a camera therewith and a camera loadable thereby

Also Published As

Publication number Publication date
CH557266A (de) 1974-12-31
FR2159335A1 (cs) 1973-06-22
FR2159335B1 (cs) 1976-10-29
GB1403037A (en) 1975-08-13
IT972393B (it) 1974-05-20
JPS4865670U (cs) 1973-08-20
JPS572277Y2 (cs) 1982-01-14
CA964604A (en) 1975-03-18

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Legal Events

Date Code Title Description
AS Assignment

Owner name: AMERICAN NATIONAL CAN COMPANY, STATELESS

Free format text: MERGER;ASSIGNORS:AMERICAN CAN PACKAGING INC.;TRAFALGAR INDUSTRIES, INC. (MERGED INTO);NATIONAL CAN CORPORATION (CHANGED TO);REEL/FRAME:004835/0354

Effective date: 19870430

Owner name: AMERICAN NATIONAL CAN COMPANY

Free format text: MERGER;ASSIGNORS:AMERICAN CAN PACKAGING INC.;TRAFALGAR INDUSTRIES, INC. (MERGED INTO);NATIONAL CAN CORPORATION (CHANGED TO);REEL/FRAME:004835/0354

Effective date: 19870430

Owner name: AMERICAN CAN PACKAGING INC., CONNECTICUT

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AMERICAN CAN COMPANY, A NJ CORP.;REEL/FRAME:004835/0338

Effective date: 19861107

Owner name: AMERICAN CAN PACKAGING INC., AMERICAN LANE, GREENW

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMERICAN CAN COMPANY, A NJ CORP.;REEL/FRAME:004835/0338

Effective date: 19861107