US3151766A - Pull tab tear strip combination for metal can end - Google Patents

Description

Oct. 6, 1964 J. HENCHERT 3,151,766

PULL TAB TEAR STRIP COMBINATION FOR METAL. CAN END Filed Feb. l0, 1961 2 Sheets-Sheet 1 INVENTOR )QHN HENCH Elzr Wauw, VME@ MA T02 N EYS J. HENCHERT Oct. 6, 1964 PULL TAB TEAR STRIP COMBINATION FOR METAL CAN END 2 Sheets-Sheet 2 Filed Feb. l0, 1961 INVENTOR. cmq H ENcHEzT ATTOQN EYS kan lL'e PULL TAB TEAR SEP?) Cltihiltnfilhl FR h'EiJ-a Cih .ENE John iienchert, River Fnrest, assigner to Continental Can Company, inc., New Yaris, N Y., a corporation of Ne Yerlr Filed 19, 3191.51, Ser. No. 88,473 l Qlainr. (Qi. E-S4) This invention relates in general to new and useful improvements in means for opening containers, such as cans, and more particularly is directed to a novel tear strip arrangement for containers including metal can ends wherein a container may be opened by merely grasping a pull tab attached to a tear strip and removing the tear strip to thereby remove a panel of the container.

One of the primary objects of this invention is to provide a novel tear strip and pull tab combination wherein the pull tab is rmly anchored to one end of the tear strip and is of a greater width than the tear strip whereby the pull tab rests upon the associated container member on opposite sides or" the tear strip to reinforce the tear strip at its starting end to eliminate the accidental rupture of the container member at the starting end of the tear strip.

Another object of this invention is to provide a novel tear strip and pull tab arrangement wherein the pull tab is provided with an end which is merely passed through an opening in the starting end of the pull tab and is thus interlocked with the pull tab, with the mechanical connection between the tear strip and the pull tab being sun ciently great to prevent the accidental removal of the pull tab from the tear strip during a tear strip removal operation.

Another object of the invention is to provide a novel connection between a tear strip and a pull tab therefor, wherein the tear strip is in no way punctured and a good mechanical connection is obtained between the tear strip and the pull tab without the utilization of a welding process.

A further object of this invention is to provide a pull tab and tear strip connection wherein the pull tab is provided with a simple boss which is passed through an opening in a tear strip and the boss upset to both form an interlock between the tear strip and the pull tab and to seal the opening in the tear strip.

Another object of the invention is to provide a novel mechanical connection between a metal pull tab and a metal tear strip wherein the pull tab and tear strip are provided with interloclred bosses and with portions of the pull tab extending into the tear strip to thus provide the desired mechanical connection without rupturing or otherwise puncturing the tear strip.

Still another object of this invention is to provide a novel connection between a tear strip and a pull tab wherein the tear strip is provided with an upstanding boss which is passed through an opening in the pull tab, after which the boss is upset, to provide a good mechanical connection between the tear strip and the pull tab and at the same time eliminate the necessity of rupturing or puncturing the tear strip.

A still further object of this invention is to provide a novel mechanical connection between a plastic pull tab and a metal tear strip wherein the tear strip is provided with an opening into which a plug portion of the pull tab is snapped and the connection between the plug portion and the adjacent metal of the tear strip being such that as the pressure on the plug portion for removal thereof is increased, the gripping of the plug by the metal of the tear strip is likewise increased to prevent the separation of the tear strip and the pull tab.

Still another obiect of this invention is to provide a novel plastic pull tab and metal tear strip connection United States Patent O 3,151,766, Patented @et 6, 1954 wherein the metal tear strip is provided with an opening through which a plug portion of the pull tab is passed, and after which the plug portion is curled to provide the necessary mechanical interlock between the pull tab and the tear strip.

A still further object of the invention is to provide a novel tear strip arrangement which includes a pull tab, the pull tab being formed of plastic and being adhesively bonded to the metal tear strip.

This invention also proposes to provide means to facilitate the starting of the tearing of a tear strip from the adjacent metal whereby the tear strip is provided with a generally semi-circular end portion which is scored more deeply than side edge portions of the tear strip, whereby a lesser starting force is required to rupture the tear strip along the score lines.

A iinal object of this invention is to provide a novel punch and die assembly for facilitating the insertion of plug portions of plastic tear strips in openings in relatively thin metal tear strips without undesirably deforming the tear strip in a manner to prevent the forming of the desired mechanical interlock.

With the above, and other objects in View that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIGURE 1 is a perspective View or an upper portion of a can having a metal can end which is provided with a tear strip and pull tab in accordance with this invention.

FEGURE 2 is a perspective view similar to FlGURE l and shows the tear strip partially removed.

FIGURE 3 is an enlarged plan View of the upper end of the can of FIGURE 1 and shows further the details of the tear strip and pull tab.

FIGURE 4 is an enlarged fragmentary vertical sectional view taken along the line 4-4 of FiGURE 3, and shows the specific details of one form of connection between the pull tab and the tear strip.

FGURE 5 is an enlarged fragmentary transverse vertical sectional View taken along the line 5 5 of FIGURE 3 and shows further the details of the connection between the pull tab and tear strip, including the fact that the pull tab overlies the metal can end on opposite sides of the tear strip to prevent the accidental rupturing of the can end along the outline of the tear strip by a downward pressure.

FGURE 6 is an enlarged fragmentary vertical sectional view taken through the metal can end and shows a modified form of connection between a metal pull tab and a metal tear strip.

FGURE 7 is an enlarged fragmentary perspective view showing the general details of a modified form of tear strip and pull tab combination.

FIGURE 8 is an enlarged fragmentary vertical sectional view taken along the line 8 8 of FIGURE 7 and shows the specific details of the connection between the tear strip and the pull tab, the shape of a connecting portion of the tear strip prior to the connection of the pull tab to the tear strip being shown by dotted lines.

FEGURE 9 is an enlarged fragmentary perspective view similar to FGURE 7, and shows a modified form of tear strip and pull tab combination.

FGURE l0 is an enlarged fragmentary sectional View taken along the line iti-l0 of FlGURE 9, and shows the specific details of the tear strip and pull tab combination including the interlock between the pull tab and the tear strip.

FGURE 1l is an enlarged fragmentary sectional view taken along the line iiil of FlGURE 9 and shows further the details of the connection between the plastic pull tab and the tear strip, including the fact that the pull tab is of suihcient width to extend outwardly of the score lines deiining the tear strip to prevent the accidental rupturing of the can end by a downward pressure on the end portion of the tear strip.

FIGURE 12 is an enlarged fragmentary vertical sectional view similar to FIGURE 11 and shows a modified form of connection between a plastic pull tab and a metal tear strip.

FIGURE 13 yis another vertical sectional view on a large scale similar to FIGURE 11 and shows a still further modied connection between a plastic pull tab and a metal tear strip.

FIGURE 14 is another enlarged vertical sectional view similar to FIGURE 11 and shows still another form of connection between a plastic pull tab and a metal tear strip. A

FIGURE 15 is a fragmentary exploded view with parts shown in section of appaartus for inserting plug portions of pull tabs, such as the pull tab of FIGURE 12, into the tear strip. FIGURE 16 is a fragmentary exploded perspective view showing still another form of pull tab and tear strip combination wherein the pull tab is adhesively secured to the tear strip.

FIGURE 17 is a fragmentary plan view showing the general outline of the tear strip at the starting end thereof and the formation of the score lines defining the same.

FIGURE 18 is an enlarged fragmentary vertical sectional view taken along the line 18-18 of FIGURE i7, and shows the specific arrangement of the scores in the various portions of the metal can end along the outline of the tear strip. Reference is now made to the drawing in detail, wherein there is illustrated in FIGURES l through 5, inclusive, a rst form of the invention. In FIGURES 1, 2 and 3, there is illustrated a conventional type of can which is generally referred to by the numeral 2G, and which includes a can body 21. and a can end 22. The can end 22 is preferably formed of a light gauge metal, and it is de- Vsirable that the metal be easily rupturable. As a result, normally the can end 22 will be formed of aluminum, although the usual metals employed in the making of the can ends may be utilized. The can end 22 is secured to the can body 21 by a conventional seam 23. The can is illustrated and described only to set forth one euvironment of the invention. The present invention is not restricted to cans, but may be used in all types of containers, etc., where it is desired to remove a portion thereof without utilizing any opening equipment, such as a can opener in the case of a can.

Reference is now made to FIGURE 3 in particular, wherein the can end 22 is illustrated as having a circumferential tear strip 24 which is defined by a pair of score lines 25, 26 with the score line 25 being disposed outermost and being disposed adjacent the seam 23 so that when the tear strip 24 is removed, substantially the entire can end 22 within the seam 23 will be removed. The score lines 25, 26 are disposed generally in concentric relation for the most part of their lengths and the score line 26 generally defines an inner panel 27.

, In order to facilitate the tearing and removal of the tear strip 24 from the can end 22, there is provided a pull tab, generally referred to by the numeral 28. The pull tab 28 is relatively elongated andis of a greater width than the tear strip 24. The peripheral edges of the pull tab 28 are reinforced by a narrow peripheral flange 29 which is bent over the upper surface of the pull tab 28, as is best shown in FIGURES 3, 4 and 5. p The pull tab 28 is provided adjacent one end thereof with a boss 3i) which projects downwardly through an opening 31 formed in the starting end portion of the tear strip 24 and crimped therebeneath, as at 32. Thus, a highly desirable mechanical connection is provided between the pull tab 28 and the tear strip 24. Although the opening 31 is formed in the tear strip 24, the can 2li remains sealed due to the effectiveness of the connection between the pull tab 2S and the tear strip 24, as is clearly shown in FIGURES 4 and 5. It is to be noted from FIGURE 5 in particular that the pull tab 28 is of a greater width than the tear strip 24 so that an accidental downward pressure on the pull tab 28 will not result in the rupturing of the can end 22 of the starting end of the tear strip 24.

The end of the pull tab 2S remote from the tear strip 24 is provided with an opening 33 therethrough. The opening 33 is for the purpose of facilitating the gripping of the pull tab 23 and may be replaced by other suitable grip facilitating means.

Reference is now made to FIGURE 6, wherein there is illustrated a slightly modiiied form of pull tab-to-tear strip connection. This connection includes a tear strip 34 which is substantially identical to the tear strip 24, but in lieu of being provided with the opening 31 is provided with a boss 35. The pull tab, which is associated with the tear strip 34, is generally referred to by the numeral 36 and includes a depending boss 37 which extends through the plane of the tear strip 34 and is seated in the boss 35 of the tear strip 34. The bosses 35 and 37 are crimped, as at 38', to interlock the bosses 35 and 37 and thus firmly mechanically connect the pull tab 36 to the tear strip 34.

Reference is now made to FIGURES 7 and 8 of the drawings, wherein there is illustrated a can, generally referred to by the numeral 3S. The can 3S, like the can Ztl, includes a can body 39 which has the upper end thereof closed by a can end 49 secured to the can body 39 by a seam 41 in the conventional manner. The can end 40 is provided with a tear strip 42 which is identical in outline to the tear strip 24.

The tear strip 42 is provided with an upstanding boss 43 which is received through an opening 44 in a pull tab associated therewith, the pull tab being generally referred to by the numeral 45. The boss 43 is initially upstanding, as indicated by dotted lines in FIGURE 8, and is crimped, as at 45, to provide the desired mechanical interlock between the tear strip 42 and the pull tab 45. By providing a boss 43 in lieu of an aperture, the problem of sealing the opening in the tear strip is eliminated. At the same time, the desired eti'icient mechanical connection is obtained.

It is to be noted that the pull tab 45 remote from the tear strip 42 is vertically offset, as at 47, to define a grip portion 48. It is also to be noted that the width of the pull tab 45 is greater than the width of the tear strip 42 so that the pull tab 45 overlies the can end 40 outside of the area of the tear strip 42 at the starting end thereof to eliminate any accidental rupturing of the can end 40 by a downward pressure being exerted on the starting end of the tearstrip 42. The pull tab 45 may be formed of any suitable material including a light gauge metal or plastic.

Reference is now made to FIGURES 9, 10 and 11, wherein there is illustrated in FIGURE 9 another can, generally referred to by the numeral 49. The can 49 includes the conventional can body 5t) having a can end 51 secured thereto by means of the customary double seam 52. The can end 50 is provided with a tear strip 53 of the same outline as the tear strips 24 and 42. The starting end of the tear strip 53 is provided with a pull tab, generally referred to by the numeral 54, and formed of a resilient deformable plastic.

The starting end of the tear strip 53 is provided with an opening 55 therethrough which is in part deiined by a downwardly and inwardly sloping annular flange 56. The pull tab 54 is formed with an integral plug 57 which is recessed, as at 58, to be hollow, the plug 57 extending through the opening 55 defined by the ange 56. The lower portion of the plug 57 is provided with an annular rib 59 which has an upwardly :flared lower portion 60 and an inwardly tapering upper portion defining a shoulder 61. The flaring of the lower portion 60 facilitates the insertion of the plug 57 through the opening 55. The terminal edge of the flange 56 rests upon the shoulder 61 and prevents the accidental withdrawal of the plug 57 through the tear strip 53.

It will be readily apparent that the pull tab 54 may be connected to the tear strip S3 by simply pressing the plug portion 57 through the opening 55 until the annular rib 59 snaps beneath the flange 56. It is also to be noted that the pull tab 54 is of a greater width than the tear strip 53 whereby the main portion of the pull tab 54 serves to support the starting end of the tear strip 53 against accidental inward displacement by a force exerted on the starting end of the tear strip 53. The end portion of the pull tab 54 remote from the tear strip 53 is provided with an upper transverse rib 62 and a lower transverse rib 63 to facilitate the grasping of the pull tab 54 and exert a tear strip tearing and removal force thereon.

In FIGURE l2, there is illustrated a slightly modified form of the tear strip to pull tab connection illustrated in FIGURE 1l. In this form, the pull tab is generally referred to by the numeral 64 and the tear strip is generally referred to by the numeral 65. The tear strip 65, like the tear strip 53, is provided with an opening therethrough defined by a flange. The opening of the connection of FIGURE l2 is referred to by the numeral 66, and is defined by an annular-flange 67 which rst extends downwardly and inwardly and then is turned inwardly at a greater angle, as at 68.

The pull tab 64 is provided with a hollow plug portion 69 which is provided adjacent the lower end thereof with an annular rib 70 having an upwardly flaring lower portion 71 and a generally square cut upper shoulder 72. The flared lower portion 71 facilitates the insertion of the plug 69 through the opening 66 and the engagement of the lower porton of the flange 67 with the shoulder 72 prevents the accidental withdrawal of the plug portion 69 through the opening 66. The lower portion of the annular flange 67 is inwardly directed, and as an upward pull is exerted on the pull tab 64, the lower portion of the annular ange 67 will be cammed inwardly to more firmly grip the plug portion 69 and thus prevent accidental removal of the pull tab 64 from the tear strip 65.

Reference is now made to FIGURE 15, wherein there is illustrated an apparatus, generally referred to by the numeral 73, for facilitating the assembling of the pull tab 64 with the tear strip 65. When the plug portion 69 of the pull tab 64 is snapped into the tear strip 65, there is a tendency for the flange 67, particularly the lower portion thereof, to straighten out. This is undesirable in that the flange 67 should retain the configuration illustrated in FIGURE l2 to provide the desired connection with the plug portion 69 of the pull tab 64. It is to this end that the apparatus 73 is provided.

The apparatus 73 includes a base 74 and a relatively movable punch 76. A bore 75 is formed in the base 74 and has an enlarged upper portion 77. The bore 75 is aligned with the punch 76 and has a coil spring 78 in the lower portion thereof. The coil spring 7S has its upper end bearing against an enlarged bottom portion 79 of an ejector pin 80. The lower portion of a die ring 81 is seated in the bore portion 77. The die ring 81 has a bore 82 into which the ejector pin 80 projects. The upper portion of the die ring 81 is provided with a seat 83 which corresponds generally to the exterior surface of the flange 67 and on which the flange 67 is intended to rest. The die ring 81 is undercut, as at 84, below the seat 83 to receive the rib 70 and may also be used to limit the upward movement of the ejector pin St).

When it is desired to assemble the pull tab 64 with the tear strip 65, the can end of which the tear strip 65 is a part is seated on the die ring 81 and the pull tab 64 is seated on the can end in the desired position with the plug portion 69 thereof aligned with the opening 66 defined by the flange 67. The punch 76 is then moved downwardly to eXert a pressure on the upper surface of the pull tab 64 which forces the plug portion 69 thereof through the opening 66. However, since the flange 67 is rseated on the seat 83, deformation of the flange 67 is prevented. As the plug portion 69 of the pull tab 64 passes through the opening 66 in the tear strip 65, it engages the upper end of the ejector pin St) and moves the same downwardly against the resistance of the coil spring 73. Vhen the punch 76 again moves upwardly, the ejector pin 89 forces the plug portion 69 upwardly with the result that the can end and the pull tab 64 are stripped from the die ring 81 as an assembly.

Reference is now made to FIGURE 13 wherein the tear strip is provided with a modified form of pull tab, generally referred to by the numeral 85. The pull tab has a plug portion 86 which is passed through the opening 66 defined by the flange 67 and after it has passed therethrough, the plug portion S6 is curled upwardly, as at 87, around the flange 67 to provide a mechanical interlock therewith. In this manner, the pull tab S5 is firmly connected to the tear strip 65. It is to be noted that the width of the pull tab 85 is greater than that of the tear strip 65 so as to resist any downward deflection of the starting end of the tear strip 65 in the event a pressure is exerted either on the pull tab 85 or directly on the tear strip 65.

in FIGURE 14, there is illustrated a can end S3 which is provided with a tear strip S9 having a simple opening 90 formed therethrough. A pull tab, generally referred to by the numeral 91, is connected to the tear strip S9 to facilitate the tearing and removal thereof. The pull tab 91 has a sleeve portion 92 which may be in the form of a hollow plug, which is passed through the opening 99 and which is reversely and outwardly curled, as at 93, to form an enlargement which underlies the tear strip 89 surrounding the opening 96. In this manner, a highly effective mechanical connection between the pull tab 91 and the tear strip 89 is formed. It is to be noted that the pull tab 91 is of a greater width than the tear strip $9 so that downward deflection of the tear strip 89 out of the plane of the can end 88 in the vicinity of the pull tab 91 is prevented.

Reference is now made to FIGURE 16, wherein there is illustrated a modified form of can construction generally referred to by the numeral 94. The can 94- includes the usual can body 95 to which a can end 96 is connected by the usual seam 97 The can end 96 is provided with a tear strip 9S which is torn from the can end 96 and removed in the opening of the can 94. The tear strip 9S is provided with an imperforate starting end 99 which is coated with a suitable thermoplastic or thermosetting adhesive 10%). The adhesive 105) is utilized in the securement of a pull tab, generally referred to by the numeral 101, to the starting end 99 of the tear strip 98. The pull tab 161 may be of any configuration, and has been illustrated as being identical to the pull tab 54, with the exception that the unnecessary plug 57 thereof has been omitted. It is to be understood that the pull tab 101 will be of suicient width to support the starting end 99 and prevent the accidental downward deflection thereof.

Reference is now made to FIGURES 17 and 18, wherein the details of the score lines defining the various tear strips at the starting end of each tear strip, are shown. For identification purposes only, the partial can end illustrated in FIGURE 17 will be considered to be the can end 22, and the tear strip, the tear strip 24. As was previously described, the tear strip 24 is defined by a pair of score lines 25, 26. As is best illustrated in FIGURE 18, these score lines 25, 26 are relatively shallow. The score lines 25 and 26 will preferably be of a depth so that the remaining metal to be torn in the removal of the tear strip 24 will have a thickness of 0.003 inch. The

ends of the score lines 25, 26 are connected together by a generally semi-circular score line 102 which has a greater base width and is of a greater depth, as is best illustrated in FIGURES 17 and 18. The depth of the score line 102 will be such that in most instances, the remaining thickness of metal to be torn will range between 0.001 inch and 0.0015 inch. By making the score line 102 much deeper than the score lines 25, 26, it will be readily apparent that a sharp upward pull on the starting end of the tear strip 24 by means of the pull tab 28 will result in the rupturing of the metal of the can end 22 along the score line 102. Once the initial rupturing has been accomplished, the tear strip 24 may be removed by continuously exerting an upward pull thereon with the tear strip 24 being torn from the can end 22 along the tear lines 2S, 26.

The advantage of the relatively deep score line 102 coupled with the supporting feature of the individual pull tab is obvious. Applicant has made the initially torn portion of the can end of sufficient weakness to facilitate the ease of tearing the starting end of the tear strip therefrom. On the other hand, by making each pull tab of a sufficient width to engage the can end outwardly of the tear strip, the tear strip is prevented from deecting inwardly due to any accidental force exerted thereon, whereby the can 20 would be opened prematurely.

It is to be noted that in some instances, the score lines defining the tear strips are formed in the upper surfaces of the can end, whereas in other instances, the score lines are formed in the undersurfaces of the can ends. This may be varied as desired, depending upon the partisular materials involved. It is also to be understood that if it is so desired, the score line 102 maybe of the same depth as the score lines 25, 26, although this would make it more difficult to initially start the tearing of the tear strip. It is also to be understood that the present invention is not intended to be limited to can ends, although this will most probably be the major use of the invention.

From the foregoing, it will be seen that novel and Vadvantageous provision has been made for carrying out the desired end. However, attention is again directed to the fact that variations may be made in the examples appended claim.

I claim:

In a container, a tear striprassembly for facilitating the opening of said container without the use of any additional device, said tear strip assembly being formed in a panel of said container and comprising a tear strip forming an integral part of said container panel, said tear strip being primarily deiined by two spaced score lines in said panel and Vincluding a starting end, a pull member overlying said tear strip starting end for facilitating the manual tearing of said tear strip from said container panel to effect the opening of said container, a permanent connection joining the tear strip starting end to the pull member, said two score lines being joined by a starting score line portion at least partially dening said tear strip starting end, said starting score line portion being of a greater depth than said two score lines and presenting a line of least resistance to rupture to facilitate the starting of the tearing of said tear strip from said container panel, and said pull member protectively overlying said starting end portion and being adapted to rest on said container panel outwardly of said tear strip to resist accidental rupture of said container panel along said starting score line portion by an accidental inward Vdisplacement of said tear strip starting end.

References Cited in the tile of this patent UNITED STATES PATENTS 2,029,329 Ljungstrom et al. Feb. 4, 1936 2,147,004 Wark et al. Feb. 14, 1939 2,670,871 Spiess et al i Mar. 2, 1954 2,792,145 Sowter Mar. 14, 1957 2,870,935 Houghtelling Jan. 27, 1959 2,946,478 V. Clair et al. July 26, 1960 2,961,755 Prince Nov. 29, 1960 2,968,864 Lee Jan. 24, 1961 2,974,824 Mansho Mar. 14, 1961 2,978,140 Walsh Apr. 4, 1961 3,034,680 teinberg May 15, 1962 3,080,088 Corrinet Mar. 5, 1963

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