United States Patent (19)
`Kaminski et al.
`
`Patent Number:
`11
`(45) Date of Patent:
`
`4,465,204
`Aug. 14, 1984
`
`54
`75
`
`73
`21
`22)
`(51)
`(52)
`58
`
`PULL TAB FOR EASYOPEN END
`Inventors: Elton G. Kaminski, Sidney; Carl F.
`McEldowney, Russia, both of Ohio
`Assignee: The Stolle Corporation, Sidney, Ohio
`Appl. No.: 513,447
`Filed:
`Jul. 13, 1983
`Int. Cl. .............................................. B65D 17/34
`U.S. Cl. .................................................... 220/269
`Field of Search ................................ 220/269-273;
`413/12
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`3,462,042 8/1969 Stolle ..............
`... 220/54
`3,762,597 10/1973 Kaminski et al.
`... 22.0/54
`... 220/54
`3,795,342 3/1974 Ashton ...........
`... 220/269
`4,096,967 6/1978 Kaminski ........
`... 220/269
`4,372,462 2/1983 Dassher et al.
`... 220/269
`4,387,827 6/1983 Ruemer, Jr. ...
`4,402,421 9/1983 Ruemer, Jr. ........................ 220/269
`
`Primary Examiner-George T. Hall
`Attorney, Agent, or Firm-Frost & Jacobs
`57
`ABSTRACT
`An easy open can end having a retained tear strip ex
`tending diametrically partly across the can end defined
`by a score line, and a graspable pull tab adjacent and
`outside the open end of the score line. The pull tab is
`provided with a nose portion to initiate a tear along the
`score line upon lifting of the pull tab. The edges of the
`nose portion are curled into a cylindrical cross-sectional
`shape to provide a high beam strength and to rigidize
`the nose portion and to prevent failure by bending be
`fore the tear strip is opened. A method for manufacture
`of the pull tab includes forming at least one relief knotch
`in the peripheral edge of the pull tab blank at the nose
`end thereof, whereby to relieve compressive forces
`when the edge is curled, and curling the peripheral edge
`of the nose portion in successive steps to form an edge
`portion of continuous cylindrical cross-sectional shape.
`7 Claims, 16 Drawing Figures
`
`
`
`EX-1011 IPR2024-01000
`
`

`

`U.S. Patent
`Aug. 14, 1984
`U.S. Patent Aug. 14, 1984
`
`Sheet 1 of 3
`Sheet 1 of 3
`
`4,465,204
`4,465,204
`
`
`
`
`
`EX-1011 IPR2024-01000
`
`EX-1011 IPR2024-01000
`
`

`

`U.S. Patent Aug. 14, 1984
`
`Sheet 2 of 3
`
`4,465,204
`
`
`
`
`
`Paya Zeta/
`
`S2S2SSess2
`AYA1a1sala
`As2a343 M
`
`
`
`
`
`loye
`
`N:
`are areas a
`SS 24-4444444 ZV2
`7
`
`EX-1011 IPR2024-01000
`
`

`

`U.S. Patent
`Aug. 14, 1984
`U.S. Patent Aug. 14, 1984
`
`Sheet 3 of 3
`Sheet 3 of 3
`
`4,465,204
`4,465,204
`
`
`
`
`
`EX-1011 IPR2024-01000
`
`EX-1011 IPR2024-01000
`
`

`

`1.
`
`PULL TAB FOR EASY OPEN END
`
`4,465,204
`2
`provides a recess for the retracted pull tab against the
`surface of the can end.
`The present invention also provides for the manufac
`ture of a pull tab having a nose portion and being sub
`jected to a plurality of successive forming operations as
`it is formed from a blank, which includes the steps of
`forming a pull tab blank, forming at least one knotch in
`the peripheral edge of the blank at the nose end thereof,
`to relieve compressive forces when the edge is curled,
`and curling the peripheral edge of the nose portion in
`successive steps to form an edge portion of continuous
`cylindrical cross-sectional shape so as to provide a high
`beam strength, to rigidize the nose portion, and to pre
`vent failure of the pull tab by bending.
`The manufacture may also include the step of coining
`a "V" shape in the pull tab immediately in front of the
`tab rivet hole to keep the tab in which the rivet hole is
`pierced from tearing during the stress of opening.
`In a preferred embodiment, the knotches are semi-cir
`cular in shape and may comprise two in number, one on
`either side of the nose portion.
`Other features of the invention will become apparent
`from the detailed description which follows.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a top plan view of an easy open can end
`incorporating the improved pull tab of the present in
`vention.
`FIG. 1A is a cross-sectional view taken on the line
`1A-1A of FIG. 1.
`FIG. 1B is a cross-sectional view taken on the line
`1B-1B of FIG. 1.
`FIG. 1C is a cross-sectional view taken on the line
`1C-1C of FIG. 1.
`FIG. 2 is a bottom plan view of the can end of FIG.
`1.
`FIG. 3 is a cross-sectional view through the can end
`of FIG. 1 taken on the line 3-3.
`FIG. 4 is a cross-sectional view through the can end
`of FIG. 1 taken on the line 4-4.
`FIG. 5 is a cross-sectional view similar to FIG. 3
`showing the initiation of opening the tear strip.
`FIG. 6 is a cross-sectioal view similar to FIG. 5
`showing the can end with the tear strip in the fully
`opened position.
`FIG. 7 is a cross-sectional view similar to FIGS. 5
`and 6 showing the can end with the tear strip in the fully
`opened position and the pull tab in its retracted position.
`FIG. 8A is a plan view of a prior art pull tab blank
`during the forming operation prior to curling of the
`peripheral edge thereof.
`FIG. 8B is a perspective view of a partially, mal
`formed pull tab formed from the pull tab blank of FIG.
`8A.
`FIG. 9A is a plan view of a pull tab blank of the
`present invention.
`FIGS. 9B through 9D are perspective views showing
`the curling of the peripheral edge of the nose portion of
`the pull tab of the present invention in successive steps
`to form an edge portion of continuous cylindrical cross
`sectional shape.
`DETAILED DESCRIPTION
`The can end of the present invention is illustrated
`generally at 1 in FIG. 1, and is of generally circular
`shape including a circumferentially extending raised
`edge 2 for attaching can end 1 to a suitable cylindrical
`
`50
`
`65
`
`25
`
`30
`
`35
`
`SUMMARY OF THE INVENTION
`The present invention is directed to a pull tab for a
`metallic beverage-type can end or the like, and more
`particularly to a pull tab which is retained to the can
`end after opening.
`Many metallic cans for holding beverages or other
`liquid products are provided with easy open ends hav
`10
`ing a pull tab attached to a tear strip defined by a score
`line in the can end which can be pulled to provide an
`opening in the end for dispensing the can contents.
`For ecological and safety reasons, many areas now
`15
`require that the tear strip and attached pull tab be re
`tained to the can end after opening. In order to meet
`these requirements, various ways have been suggested
`for insuring that the tear strip and pull tab do not be
`come separated from the can end. There are a number
`of prior art easy open can ends available, but the pri
`20
`mary problem therewith is that the retained tab ends are
`difficult to open, require use of thick metal gauges and
`complicated and low productivity tooling. Since these
`versions are difficult and expensive to produce, the
`higher production costs are usually passed on to the
`COSle.
`The present invention has developed a pull tab for use
`on retained pull tab easy open can ends which requires
`less tooling stations, utilizes less metal, is conducive to
`higher production rates and makes the can end easier to
`open. In the preferred embodiment illustrated, an easy
`open can end is provided having a score line defining a
`tear strip. The score line is generally U-shaped with the
`open end of the U towards the center of the can end and
`being interrupted so that the tear strip will be captively
`retained on the underside of the can end when torn
`open. An integral rivet is provided adjacent the open
`end of the U outside the score line, and the pull tab is
`secured to the can end by means of the rivet.
`The pull tab is provided with a nose portion to initiate
`a tear along the score line upon lifting of the pull tab.
`The edges of the nose portion are curled into a cylindri
`cal cross-sectional shape to provide a high beam
`strength and to rigidize the nose portion and to prevent
`failure by bending before the tear strip is opened.
`45
`When the pull tab is raised, the nose portion thereof
`initiates the tear along the score line, causing the tear
`strip to bend downwardly along a transverse line in
`front of the rivet, and when raised further, causing the
`score line to tear therearound, except for the inter
`rupted portion thereof, so that the tear strip is captively
`retained on the underside of the can end, and when the
`tear strip is fully open, to be retracted so as to lie sub
`stantially flush against the surface of the can end.
`In a preferred embodiment of the present invention,
`55
`the curl extends completely around the peripheral edge
`of the nose portion of the pull tab. Additionally, the pull
`tab is provided with a finger end opposite the nose
`portion and the curl fades into a conventional hem
`toward the finger end on either side of the nose portion.
`A coined “V' shape may be provided in the pull tab
`immediately in front of the tab rivet hole to keep the tab
`in which the rivet hole is pierced from tearing during
`the stress of opening.
`Finally, a recessed portion may be provided in the
`can end and the score line may be located within the
`recessed portion. The recessed portion preferably ex
`tends from the open end of the U across the can end and
`
`EX-1011 IPR2024-01000
`
`

`

`4,465,204
`3
`4.
`the difficulty in producing this type of curl is this ti;
`beverage can 3 or the like as is well known in the art. In
`general, can end will be manufactured of a relatively
`metal must compress as the curl is formed. In practice,
`ductile metal, such as aluminum, for example, but may
`the curled edge portion 23 is discontinuous and mal
`be made from plastic or other materials as required.
`formed, caused by the metal attempting to relieve the
`compressive forces.
`A retained tear strip 4 extends across the can end 1
`from a position spaced just inwardly of the raised edge
`The manufacture of the pull tab 10 of the present
`2 to approximately the center of the can end 1. Tear
`invention is shown in FIGS. 9A through 9D. During
`strip 4 is defined by a score or tear line 5 being generally
`the manufacturing process, at least one pull tab blank 24
`U-shaped with the open end 6 of the U towards the
`is formed, perferably in a metallic strip 25, as shown in
`center of the can end. Score line 5 is interrupted at 7 so
`FIG. 9A. At least one relief knotch 26 is then formed in
`10
`that the tear strip will be captively retained on the un
`the peripheral edge 27 of the blank 24 at the nose por
`derside 8 of the can end 1 when torn open.
`tion 28 thereof. The knotches 26 may be semi-circular in
`An integral rivet 9 is positioned adjacent the open
`shape, which is achieved by punching circular holes
`end 6 of the U-shaped score line 5 outside the score line
`into the strip 25. It will, of course, be understood that
`5, and a graspable ring-like pull tab 10, which may be of
`these relief knotches 26 may be of a shape other than
`15
`any desired size and configuration, is secured to the can
`circular and that the number may vary, although prefer
`end 1 by means of the rivet 9. The pull tab 10 is pro
`ably the knotches 26 comprise two in number, one on
`vided with a nose portion 11 to initiate a tear along the
`either side of the nose portion 28.
`score line 5 upon lifting of the pull tab 10 to tear open
`In FIGS. 9B through 9D, it will be seen that the
`the tear strip 4 as is well known in the art. The periph
`peripheral edge 27 of the nose portion 28 of the pull tab
`20
`eral edge 12 of the nose portion 11 is curled into a cylin
`blank 24 is curled in successive steps to form an edge
`drical cross-sectional shaped curl or edge portion 13 to
`portion 11 of continuous cylindrical cross-sectional
`provide a high beam strength and to rigidize the nose
`shape, so as to provide a high beam strength, to rigidize
`portion 11 and to prevent failure by bending before the
`the nose portion 28 and to prevent failure of the pull tab
`tear strip 4 is opened. The curl 13 preferably extends
`10 by bending. The compressive forces during curling
`completely around the peripheral edge 12 of the nose
`are relieved by the relief knotches 26. As will be seen,
`portion 11 of the pull tab 10. As can be seen, the pull tab
`when the metal is curled, when the relief knotches 26
`10 is provided with a finger end 14 opposite the nose
`are provided, the curl forms nicely and the knotches 26
`portion 11. The curl 13 preferably fades into a conven
`are almost closed in the final curl.
`tional hem 15 toward the finger end 14 on either side of
`The pull tab construction of the present invention
`30
`the nose portion 11.
`provides a curled edge portion 11 which is very strong
`As best seen in FIGS. 1, 1B and 1C, a coined 'V'
`and allows use of aluminum in the 0.014 inch to 0.016
`shape 29 is provided in the pull tab 10 immediately in
`inch thickness range as opposed to the 0.016 inch to
`front of the tab rivet hole 30 to keep the tab 24 in which
`0.018 inch thickness range now in commercial use. Fur
`the rivet hole 30 is pierced from tearing during the
`ther, the number of operations required to produce the
`35
`stress of opening.
`pull tab 10 can be reduced to ten as compared to the
`A recessed portion 16 is provided in the can end 1
`sixteen or more operations used for other prior art re
`with the score line 5 being located therein. As can be
`tained pull tabs.
`seen, the recessed portion 16 extends from the open end
`It will also be seen that during the manufacture of the
`6 of the U-shaped score line 5 across the can end 1 to
`pull tab 10, a coined “V' shape 29 is provided in the pull
`provide a recess for the retracted pull tab 10.
`tab 10 immediately in front of the tab rivet hole 30 to
`In a preferred embodiment, the tear strip 4 may be
`keep the tab 24 in which the rivet hole is pierced from
`provided with a suitable raised strengthening rim 17 of
`tearing during the stress of opening.
`any desired configuration, but which, as shown, is gen
`It will be understood that the changes in the details,
`erally U-shaped with the open end 18 of the U toward
`materials, steps and arrangements of parts, which have
`45
`the rivet 9.
`been herein described and illustrated or to explain the
`At this point, the pull tab 10 and tear strip 4 will
`nature of the invention, may be made by those skilled in
`appear as shown in FIGS. 5 and 6.
`the art within the principle and scope of the invention as
`expressed in the appended claims.
`Turning to FIG. 5, it will be seen that when the pull
`tab 10 is raised, the nose portion 11 thereof initiates a
`What is claimed is:
`50
`tear along the score line 5, causing the tear strip 4 to
`1. In an easy open can end having a score line defin
`bend downwardly along the line indicated at 19. The
`ing a tear strip, said score line being generally U-shaped
`exact position of this bend may vary from a point sub
`with the open end of the U towards the center of said
`stantially tangent to the front of the rivet 9 to a point
`can end, said open end being interrupted so that said
`perhaps 1/16th inch or more behind the rivet 9, i.e.
`tear strip will be captively retained on the underside of
`away from the nose portion 11. As the pull tab 10 is
`said can end when torn open, an integral rivet adjacent
`raised further, the score line 5 is caused to tear there
`the open end of the U outside said score line, and a pull
`around, except for the interrupted portion 7, as best seen
`tab secured to said can end by means of said rivet, said
`in FIG. 6. Accordingly, the tear strip 4 is thus captively
`pull tab having a nose portion to initiate a tear along
`said score line upon lifting of said pull tab, the edges of
`retained on the underside 8 of the can end 1. When the
`pull tab 10 has been raised so that the tear strip 4 is fully
`said nose portion being curled into a continuous cylin
`open, as best seen in FIG. 6, it may be retracted so as to
`drical cross-sectional shape to provide a high beam
`lie substantially flush against the surface of the can end
`strength and to rigidize said nose portion and to prevent
`1 within the recessed portion 16, as best seen in FIG. 7.
`failure by bending before said tear strip is opened,
`A prior art pull tab 20 is shown in FIGS. 8A and 8B.
`whereby said pull tab, when raised, the nose portion
`Note that the pull tab 20 is formed from a blank and that
`thereof initiates a tear along said score line, causing said
`the peripheral edge 21 of the nose portion 22 is curled in
`tear strip to bend downwardly along a transverse line in
`successive steps to form an edge portion 23. However,
`front of said rivet, and when raised further, causing said
`
`60
`
`65
`
`25
`
`55
`
`EX-1011 IPR2024-01000
`
`

`

`4,465,204
`6
`5
`4. The can end according to claim 1, wherein a
`score line to tear therearound, except for said inter
`coined "V" shape is provided in said pull tab immedi
`rupted portion thereof, said tear strip thus being cap
`ately in front of said rivet to keep said pull tab from
`tively retained on the underside of said can end, and
`tearing during the stress of opening.
`when said tear strip is fully opened, to be retracted so as
`5. The can end according to claim 1, wherein a re
`to lie substantially flush against the surface of said can
`cessed portion is provided in said can end and said score
`line is located within said recessed portion, said re
`end.
`cessed portion extending from said open end of the U
`2. The can end according to claim 1, wherein said
`across said can end to provide a recess for said retracted
`curl extends completely along the peripheral edge of
`pull tab.
`said nose portion.
`6. The can end according to claim 1, wherein said tear
`3. The can end according to claim 1, wherein said pull
`strip is provided with a raised strengthening rim.
`tab is provided with a finger end opposite said nose
`7. The can end according to claim 6, wherein said
`portion and said curl fades into a conventional hem
`strengthening rim is generally U-shaped with the open
`toward said finger end on either side of said nose por
`end of the U toward said rivet,
`15
`sk
`k
`k
`tion.
`
`10
`
`k
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`EX-1011 IPR2024-01000
`
`