US3687099A - Scoring metal container components - Google Patents

Scoring metal container components Download PDF

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Publication number
US3687099A
US3687099A US882451A US3687099DA US3687099A US 3687099 A US3687099 A US 3687099A US 882451 A US882451 A US 882451A US 3687099D A US3687099D A US 3687099DA US 3687099 A US3687099 A US 3687099A
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US
United States
Prior art keywords
scoring
component
score
blade
faces
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
US882451A
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English (en)
Inventor
Jozef Tadeusz Franek
Peter Rhodes
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.)
Crown Packaging UK Ltd
Original Assignee
Metal Box PLC
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Filing date
Publication date
Application filed by Metal Box PLC filed Critical Metal Box PLC
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Publication of US3687099A publication Critical patent/US3687099A/en
Anticipated expiration legal-status Critical
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects
    • B21D51/16—Making hollow objects characterised by the use of the objects
    • B21D51/38—Making inlet or outlet arrangements of cans, tins, baths, bottles, or other vessels; Making can ends; Making closures
    • B21D51/383—Making inlet or outlet arrangements of cans, tins, baths, bottles, or other vessels; Making can ends; Making closures scoring lines, tear strips or pulling tabs

Definitions

  • a tool for scoring a metal container component has a scoring blade having two faces which define the shape of the score and which as viewed in section converge substantially to a point.
  • the angle between the two faces is of the order of 75 to 120 and is preferably at least 90, the optimum angle being 90.
  • the specification also described a method of scoring the component in which the scoring blade is engaged with a portion of the component which is radiused upwards towards the blade. 4
  • the scoring tool In addition to the considerable energy needed, the scoring tool must be made with precision and is thus expensive to produce, the tool is found in practice to have a relatively short life when used for scoring ferrous metals such as tinplate and to be subject to breakage at the corners thereof which are subject to the shearing stresses, and due to excessive work-hardening the scores produced are often such that when the components are secured to containers the scores are apt to fracture if the containers are subjected to mis-use as by dropping or knocking thereof. It is further found that the scoring process tends to cause disintegration of the protective film, usually a coating of lacquer, which is applied to the surface of the component opposite that in which the scoring is effected.
  • the scoring tool comprises a head portion connectable to the ram of a press and extending from the head a scoring blade having two faces which define the shape of the score to be formed in the component, which faces in section converge substantially to a point, and the angle between which is of the order of 75 to 120. Desirably the angle between the faces is at least 90 and in the preferred embodiment the angle between the faces is substantially 90.
  • FIG. 1 diagrammatically illustrates scoring when using the known form of scoring tool provided with a trapezoid shape scoring blade
  • FIG. 2 illustrates the manner in which the scoring blade of FIG. 1 tends to fail
  • FIG. 3 illustrates the method of scoring when using a scoring tool according to the invention
  • FIG. 4 diagrammatically illustrates the mode of operation of the scoring tool of FIG. 3,
  • FIG. 5 illustrates the manner in which the blade of FIG. 3 avoids the tendency to failure of the blade of FIG. 1,
  • FIG. 6 illustrates a part of a can end seamed to a can body
  • FIG. 7 is a top plan of the can end of FIG. 6.
  • FIGS. 1 and 2 are illustrative of the known form of scoring tool provided with a trapezoid shaped scoring blade 1.
  • this blade When this blade is used for scoring a tinplate can end 2 the compound angle between the blade flanks 3, 4 is usually of the order of between 50 and 60 and the width of the blade face 5 depends on the nature of the tinplate.
  • the blade 1 induces high stresses in the can end 2 and the action of scoring produces primarily compressive stress equal to the characteristic plastic stress of the can end which gradually work hardens as the deformation progresses.
  • the material beneath the face 5 undergoes an extrusion process which is resisted by the friction forces between the scoring blade and the die face, not shown.
  • FIG. 1 where the original rectangle a0, b0, 00, d0 of material has been transformed by reduction of thickness to rectangle a1, bl, cl, d1 with considerable lateral movement of material as indicated at al, d1, a2, d2 and b1, cl, b2, 02.
  • the pressure exerted by the material being scored on the face 5 of the scoring blade is accentuated when work hardening material such as tinplate is used, and is influenced by the surface finish of both the scoring blade 1 and the support anvil, not shown, and by the width of the face 5.
  • This pressure may reach a critical magnitude which is manifested by a phenomenon sometimes referred to as a Stress Hill.
  • the pressure in the scored material, combined with the frictional stresses on the face 5, induce shear stresses in the scoring blade.
  • the relevant directions of these shear stresses are inclined at 45 to the face 5, as shown in FIG. 2, and create lines 7, 8 of potential failure which often result in the breaking off of the corners 9, 10 of the blade.
  • a scoring tool which comprises a head portion 11, FIG. 3, connectable to the ram, not shown, of a press and extending from the head 11 is a scoring blade having two faces 12, 13 which define the shape of the score, for example the score 14, FIG. 7, to be formed in the component 15 which for the purposes of this description is considered to be a tinplate can end for a container 16, FIG. 6.
  • the two faces l2, l3 converge substantially to a point 17 and the angle between the faces 12, 13 is substantially
  • the point 17 is slightly radiused; for example the radius is of the order of less than 0.0005 inch.
  • the blade so constructed has the strength to resist the shear stresses during a scoring operation because the potential failure lines 7, 8 do not emerge from the faces 12, 13 of the blade. This also has the effect of diminishing the Stress Hill condition because the scored material is cut by the blade, rather than extruded as is the case with the known kind of blade I discussed above.
  • the scoring tool of FIG. 3 is more economical to manufacture than is the blade 1 because the tool of FIG. 3 has only two faces 12, 13 to be shaped and finished to a high degree as compared with the three faces 3, 4 and 5 of the tool 1. It is further found that efficient scoring can be efiected by the use of the tool of FIG. 3 with much lower pressures as compared with those necessary when using the tool of FIG. 1.
  • the method of scoring a tinplate container component comprises locating the component 15 on a stationary anvil 18, FIG. 3, having a radiused upper surface to engage the component; and cutting into the component the desired score 14 by impelling against the component the scoring blade having the two faces 12, 13 which define the shape of the score 14, which as described above in section converge substantially to a point 17, and the angle between which is substantially 90.
  • the scoring tool may be stationary and the anvil impelled against a component 15 located on the scoring tool. It is of importance that the surface 11a of the head 1 l and the surface 18b of the support 180 for the anvil 18 to be accurately machined in order to obtain proper control of the thickness of the residual metal forming the score 14.
  • angles greater than 90 can be as high as about 120. If the angle is slightly less than 90 there will be a theoretical tendency for slight blade fracture to occur, but in some instances in practice this tendency may be sufficiently negligible for an angle in the range 75 to 90 to be acceptable.
  • the portion 19, FIG. 3, of material to be scored is bent.
  • a radiused portion 19 is formed in the component 15 to be directed upwards towards the scoring tool and to be engaged by the scoring tool as shown in FIG. 3.
  • the radiused portion 19 is formed by conforming it to the profile of the radiused upper surface of the anvil 18.
  • the component 15 is a can end and the can end has a chuck wall 20 which is connected with a seaming panel 21 and through a chuck radius 22 with a central panel 23.
  • the radiused portion 19 is formed in the central panel 23.
  • the score 14 is conformed substantially to the shape of the perimeter of the can end and is located near to the chuck radius 22.
  • the seam would be central panel 23 with an annular portion 25 for the attachment thereto, as by soldering 26, of a wire opening tab 27 having an end portion 28 located over the score 14 and arranged when the can end is seamed to the can 16 to effect initial rupturing of the score.
  • the annular portion 25 slopes downwards, FIGS. 3 and 6, from the radiused portion 19 to a depression 2! in the central panel.
  • the finger gripping portion 30, FIG. 7, of the opening tab 27 extends over the depression 29 to be capable of being easily raised by the fingers of a hand.
  • Another advantage of the use of a scoring tool as described with reference to FIGS over that of FIG. 1 is that when the portion bounded by the score is removed the raw edge left by said removal is less apt to cut or damage the hand of the consumer, for example while extracting the contents from the container.
  • a method of scoring a metal container component comprising cutting into the component the desired score by locating the component relative to one of a pair of scoring tools of which one is an anvil and the other a scoring head having a scoring blade formed by two faces which define the shape of the score to be formed in the component, which faces in section converge substantially to a point and the angle between which is of the order of between to and impelling against the component the other of the tools, together with the further step of preforming the component by forming therein a radiused portion arranged to be directed upwards towards the scoring tool and said radiused portion being engaged by the scoring blade.
  • the component is a can end having a chuck wall connected with a seaming panel and through a chuck radius with a central panel, wherein said radiused portion is formed in the central panel.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Packages (AREA)
  • Cartons (AREA)
  • Rigid Containers With Two Or More Constituent Elements (AREA)
US882451A 1969-01-10 1969-12-05 Scoring metal container components Expired - Lifetime US3687099A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0700/69A GB1249687A (en) 1969-01-10 1969-01-10 Improvements in scoring metal container components

Publications (1)

Publication Number Publication Date
US3687099A true US3687099A (en) 1972-08-29

Family

ID=9726510

Family Applications (1)

Application Number Title Priority Date Filing Date
US882451A Expired - Lifetime US3687099A (en) 1969-01-10 1969-12-05 Scoring metal container components

Country Status (8)

Country Link
US (1) US3687099A (enrdf_load_stackoverflow)
BE (1) BE744070A (enrdf_load_stackoverflow)
DE (1) DE2000610A1 (enrdf_load_stackoverflow)
FR (1) FR2028084B1 (enrdf_load_stackoverflow)
GB (1) GB1249687A (enrdf_load_stackoverflow)
MY (1) MY7200117A (enrdf_load_stackoverflow)
NL (1) NL7000198A (enrdf_load_stackoverflow)
ZA (1) ZA698486B (enrdf_load_stackoverflow)

Cited By (5)

* 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
US4122791A (en) * 1977-06-30 1978-10-31 Dayton Reliable Tool & Manufacturing Company Method and apparatus for scoring an enameled metal surface
AU2002346591B8 (en) * 2001-11-27 2003-06-10 Omnitech International, Inc. Easy-open container end
US6761281B2 (en) 2002-11-26 2004-07-13 Rexam Beverage Can Company Modified score for smooth openability
WO2013090235A3 (en) * 2011-12-12 2013-09-12 Sonoco Development, Inc. Easy-open metal end for a container, and method for making same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3688718A (en) * 1969-10-23 1972-09-05 Aluminum Co Of America Method and apparatus for scoring metal container ends
US4006700A (en) * 1975-05-05 1977-02-08 Usm Corporation Method for making container closures
WO2008144893A1 (en) * 2007-05-25 2008-12-04 Magna International Inc. Integrated die trim and method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB557256A (en) * 1943-07-02 1943-11-11 Easycantop Ltd Improved means for scoring sheet material or of containers or other articles of sheet material
US2777410A (en) * 1950-10-17 1957-01-15 Walensky Benno Apparatus for scoring can lids
US3334777A (en) * 1965-06-16 1967-08-08 Fraze Ermal C Container with pre-incised tear strip
US3359773A (en) * 1964-03-03 1967-12-26 Metal Box Co Ltd Scoring of thin sheet metal
US3411470A (en) * 1965-01-22 1968-11-19 Ermal C. Fraze Can top
US3416699A (en) * 1967-09-05 1968-12-17 Continental Can Co Vented easy opening can

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1414660A (fr) * 1964-11-26 1965-10-15 Continental Can Co Clef de tirage, pour l'ouverture des extrémités de boîtes de conserve

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB557256A (en) * 1943-07-02 1943-11-11 Easycantop Ltd Improved means for scoring sheet material or of containers or other articles of sheet material
US2777410A (en) * 1950-10-17 1957-01-15 Walensky Benno Apparatus for scoring can lids
US3359773A (en) * 1964-03-03 1967-12-26 Metal Box Co Ltd Scoring of thin sheet metal
US3411470A (en) * 1965-01-22 1968-11-19 Ermal C. Fraze Can top
US3334777A (en) * 1965-06-16 1967-08-08 Fraze Ermal C Container with pre-incised tear strip
US3416699A (en) * 1967-09-05 1968-12-17 Continental Can Co Vented easy opening can

Cited By (8)

* 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
US4122791A (en) * 1977-06-30 1978-10-31 Dayton Reliable Tool & Manufacturing Company Method and apparatus for scoring an enameled metal surface
AU2002346591B8 (en) * 2001-11-27 2003-06-10 Omnitech International, Inc. Easy-open container end
US20030116570A1 (en) * 2001-11-27 2003-06-26 Olson Christopher J. Easy-open container end
US6817819B2 (en) * 2001-11-27 2004-11-16 Omnitech International, Inc. Easy-open container end
AU2002346591B2 (en) * 2001-11-27 2007-06-07 Omnitech International, Inc. Easy-open container end
US6761281B2 (en) 2002-11-26 2004-07-13 Rexam Beverage Can Company Modified score for smooth openability
WO2013090235A3 (en) * 2011-12-12 2013-09-12 Sonoco Development, Inc. Easy-open metal end for a container, and method for making same

Also Published As

Publication number Publication date
DE2000610A1 (de) 1970-07-30
MY7200117A (en) 1972-12-31
ZA698486B (en) 1971-09-29
FR2028084B1 (enrdf_load_stackoverflow) 1974-02-15
NL7000198A (enrdf_load_stackoverflow) 1970-07-14
GB1249687A (en) 1971-10-13
BE744070A (fr) 1970-07-06
FR2028084A1 (enrdf_load_stackoverflow) 1970-10-09

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