US2978140A - Container opening devices - Google Patents

Description

April 1961 J. E. WALSH 2,978,140

CONTAINER OPENING DEVICES Filed May 10, 1960 Inventor: Jq/m Z. Wa/s/z .By hmflffo/"my 2,978,140 CUNTAINER OPENING DEVICES Filed May 10, 1960, Ser. No..28,039 s Claims. 01. 220-52 This invention relates to opening devices for covers of metallic containers which utilize tear strips and opening keys. One such opening device has a tear strip lying in the plane surface of the cover and extending around the cover just inwardly of its perimeter with the key permanently secured as a second class lever to one end of the tear strip. The end to which the key is attached is in the form of an inwardly projecting tab. To open the cover, the inner end of the key is lifted pivoting it about the other end as a fulcrum which pulls up on the tab and breaks the end of the tab from the container. Thereafter, the remainder of the tab and the tear strip is removed by either a continuous pull on the key or by turning the key bodily about its own axis. vIn the latter operation the key is first pivoted upwardly about its fulcrum until the lifting end turns over and projects beyond the outer margin of the container, whereupon the key is wound about its own axis with the tear strip forming a coil about the fulcrum end. However, on relatively small containers with diameters not much larger than the axial length of the key, the tear. strip is formed with a continuous sharp curve of small radius making the accurate formation of the coil about the key difiicult. This causes the coil to have a tendency to slip off the key which is obviously undesirable in that it impedes the opening process. Also in instances where the tear strip has straight runs plus sharp bends, as for example, at the corners of flat rectangular sardine cans, the strip is extremely difficult to coil and likewise as a tendency to slip. off the key.

One object of this invention is to provide a cover for a metallic container having a'tear strip and opening key permanently secured thereto, shaped and positioned rela tive to each other and to the cover so thatwhenthe strip is broken open and the key .wound there' is an accurate formation of coil about its end without slipping from the key. i

Another object of this invention is to provide acover having an opening key permanently secured to a tear strip which has a small radius of curvature relative to the size of the key with means on the key for controlling the formation of a coil of the tear strip material on the as the key is turned bodily about its axis.

When the width of the key at the fulcrum end is equal to or less than the width of the inwardly projecting tab of the tear strip there is a tendency for the fulcrum to puncture the tear strip or depress it into the can which is obviously undesirable. I

Accordingly, it is another object of this invention to provide a cover for a container having a tear strip and an opening key permanently secured thereto, which key is adapted to break open the tear strip without depressing it into the container.

In accordance with these objects and as a feature of this invention, there is provided a cover for a metallic container having a prescor ed tear strip formed in its surface and extending around the cover just inside'its pe- United States Patent key i atented Apr. 4, 1961 ripheral edge. The tear strip has an inwardly projecting tab or starting portion provided with a permanently secured opening key in the form of a second class lever to pry the tab from the cover. The key has a lifting portion at one end adapted to be gripped by the fingers and a fulcrum on the other end separated by a narrow intermediate portion. The key is secured to the tear strip by a spot weld intermediate of its ends. The fulcrum of the key may be either a bar extending transverselyof the axis of the key or a straight edge including projecting ears, the fulcrum being of a greater width than both the tab and the intermediate portion of the key so that when the key is lifted, pivoted about the fulcrum and extended beyond the edge of the can, the tab overlies the upturned underside of the key and the ends of the fulcrum or the ears extend outwardly from beneath the tab.

The fulcrum in whatever form it may be constructed, must be located inwardly of the inner edge of the peripheral portion of the tear strip an amount equal to its own breadth (or half its circumference if it is a bar or rod) such that when the key is pivoted 180 about the fulcrum, the ends of the fulcrum or ears are still within the inner edge of the peripheral portion of the tear strip. These projecting portions of the fulcrum bar or ears then serve as guides for the formation of the coil of the tear strip as it is wound about the key, thereby assuring that the coil does not slip off the key particularly where it proceeds around sharp bends or curves having small radii. As long as the fulcrum end of the key is wider than the projecting tab of the tear strip insofar as preventing the tear strip from being depressed into the container, it is immaterial whether it is greater than, equal to or less than the intermediate and lifting portions of the key. The single requirement for preventing depression is that the fulcrum be wider than or bridge the tab of the tear strip.

The above and other features of the invention, including various novel details of construction and combinations of parts will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular cover embodying the invention is shown by way of illustration only and not as a limitation of the inven tion. The principles and features of this invention may be employed in varied and numerous embodiments without departing from the scope of the invention.

' In the drawings,

Fig. 1 is a plan view of a circular cover for a metallic container having a tear strip and opening key embodying I the invention;

. Fig. 2 is a plan view of the container opening device shown in Fig. l with the opening key lifted and turned to the outside of the cover;

Fig. 3 is a plan view similar to Figs. 1 and 2 with the 4 key having been rotated and a portion of the strip severed from the cover and wound on thekey;

Fig. 4 is an alternative form of opening key; and, Fig. 5 is a showing of a rectangular container cover embodying the invention.

The invention is illustrated in Figs. 1 through 3 in g a circular cover 2 adapted to be secured by double-seaming or any other convenient means to the body of a container. The cover 2 is provided with a prescored tear strip 4 which is located adjacent the inner edge of the crest 6 which, after double-seaming, forms the uppermost portion of the cover. The tear strip 4 extends around the perimeter of the cover being formed by two concentric peripheral score lines 8 and 10. Contiguous with the peripheral portion of the tear strip is an inwardly projecting tab 12 which is terminated by an arcuate portion 14 of the inner score line 10. An open- 4 ing key 16 overlies the arcuate portion of the tab 12 crum portion "of the key s of greater width than the tab 12 so that the fulcrum member (including the ears 2 6) extends'outwardly on both sides of'the projecting 'A spot weld 28 joins the intermediate portion of the key 20 to the tab .12 to secure the key permanently to the tab and thus making the key a second class lever.

The edge 24 of the fulcrum end of the key is spaced inwardlyfrom the inner peripheral score line "an amount equal to or greater than the breadth'of the f uieruni member, said breadth being defined as the dimension' of the ears 26 taken axially ofthe key 'which is between the fulcrum and lifting ends. 1 Fig.4 illustrates an alternative form of key wherein the fulcrum member isa bar or rod 30 of any desired crosssection secured to the intermediateportion32 of the key.' The lifting portion of the key 33 may be of any configuration, fiat'or contoured without departing from the'scope of this invention. Whetherthe crosssection of the fulcrum bar is circular, square, rectangular or any 'other configuration, its left-hand end 34 must be spaced inwardlybf the inner peripheral score line '10 of .a' cover ar'nountequal to at least one-half the circumference of'thefulcrum bar.

The spacing of the edge of the fulcrum member, as well"as the width of the member (orlthe ea'rs" 26), is critical as will now beapparent from an inspection of Figsj 2 and 3. When the lifting end '18 ofthe key is raised and the entire key pivoted about the'fulci'um member 22, the arcuate portion 14of the tab 12isbrpken away from' the cover. After the tab has been broken out the key may either be pulled from the cover to sever the remaining or peripheral portion of the tear strip from the cover, or' the pivotal movement maybe continued until the key occupies'the Fig. 2 position withthe tear strip overlying the then upturned undersurface of the key. Note at this time, the ears 26 or the ends of the'fulcrum bar, as the case may be, project outwardly from beneath the tab but are located wholly within means-er :arcu'ate score line 10. The key is then in'position 'to be turned bodily about its own "axis to assume, first, the "solid line and then the dotted line position shown in Fig. 3 while the tear strip 4 is coiled about the intermediate portion of the key. Due to thepresence ofthe prbjecting ears 26 or ends of thefulcrum bar, the coil is maintained on the key'and is pre'vented fromf sliding nw o he @an- W nd n i c fi me iu e t t i -he' ee ser sd o until i s e itt t- "(ms of the tear strip'havebeen gevered' su'clfthatlthe cover can readily be removed? Should, however, the .edge of the fulcrum be' positioned adjacent the'score line 10, after one turn the ears'would be covered by thethe coil. a

Fig. 5 illustrates the tear strip andkey secu edtoa cover .on a rectangular or sardineit'ypefcani' "Itf'will e n h 'th y qu'n .arq inl th f h p som r the an ther w be]ss sider bl fi n q for the tear strip coilj'to slide olf the keyand in snch applications the benefits" ac'co rded by the projecting bars or projectingends offthe ruler'm'n memberfvlvill as 36st ig y ppm partially coiled strip andbe of no value 'in controlling "While thiinve'ntion has been described as embodied in covers for; metallic" containers, it "will be unde'rstoodthat it is'e'ciually applicableftbjcovers for containers e walls of which may"b formed parfiauyer ehtlrelyfof ma erials a 1 n-w" m w:

. 4 new and desire to secure by Letters Patent of the United States is:

l. A cover for a metallic container having in its surface score lines defining an inwardly extending tab, a rigid class two lever adapted to break open instantaneously the inner end of the tab, said lever being located on the cover and having at one end a fulcrum wider than the inner end of the tab to bear on the cover surface on both sides of the score lines defining the tab, an interslsqi p Rad a 9f t lever being pe a nt y se u ed only a h fa v.t an area dia snt't rum Sa lever having a lifting portion at the end opposite "the fulcrum whereby when the lifting portion is raised the fulcrum endbears downwardly on the cover thereby using the full mechanical advantage of the lever to pry up the inner end of the tab and initiate the tearing out of said tab.

2. A cover for a metallic container having in its surface 'scoije'dines defining'a tear strip with a continuing inwa'rldlyexte'nding'tab portion, a' rigid class'two lever adapted tofbreak open instantaneously the inner endio'f theft'ab, 'said lever being'located on the cover and having at"orie'end"a' fulcrum wider than the tab to bear on the eoversnrf ce on both sides of the score lines defining the"tab,'fan intermediate portion ofthe lever being permanently"s'ecur"ed onl y'to' th'e tab at an area adjacent the fulcrum;"said lever having a'lifting' portion at the end opposite the fulcrum whereby when the lifting portionis raised'the fulcrum end bears downwardly on the cover thereby'using the'full' mechanical advantage of the lever to pry up the inner end ofthe tab and initiate the'tearing r .1. It. r .4. c.-

"'3;"'A"cover for a metallic container having in its surfacescoreilines defining a peripheral tear strip with a continuing inwardly extending tabportion, a' rigid class two'tlever' adapted to break open instantaneously theijnner 'end 'of'the'tab, said leverbeing located on the cover andzha'vingat'one end'a fulcrum 'wider'than the tab with at;leasta'portion bearing on the cover surface inside the peripheralportion of the tear 'strip and laterally of said tab portion," an intermediate p'ortionof the lever being permanently secured only to the tab at an area adjacent the fulcrum, said 'lever having a .lifting'portion at the end opposite the .fulcrum whereby when the lifting portion is raised theifulcrum end 'bears downwardly 'on the cover thereby'using the full mechanical advantage of the leverto' pry up the inner end of the tab to initiate tearing out of said strip without depressing the tab into'the co'ntainer; l

.4. A cover for a metallic container having in its surface score lines" defining a peripheral tear 'strip' with a continuingin'wardly extending tab portion, av rigid class two:,lever adapted to. break open instantaneously the linne're'n'd ofthetab, saidlever having a lifting portion at one end, an intermediate portion permanently secured onlytothef'tab and atthe end opposite the' lifting portion a.f ulcrum member wider than both the tab and the intermediate portion of the.lever, said fulcrum member being located outhe coverto bear on the coversurface. inside the peripheral portion of the tear strip and laterally of said tab portion whereby when the lever is lifted, pivoted about v thefulcrurn member and the lifting portion extendedtogthe outside of the; cover the tab portion is instantaneouslyibroken open from the cover-and overlies thejthen,upturnedunderside of the lever-with a portion of the fulcrum member extending outwardlyfrom'ben athlthetab/ Ac rn: to rnetal c conta r having in t su iaesdetir in aperip ra tea st n t 3 9 n...a away. P 9i9t aa t b q gn. arenas. tw leer adapted to break open instantaneously theinner end ofthe tab, said lever, having alifting portion at one iori'p'ermanentlysecured only flaving thus described my invention, what I claim as itbftiddofih lever, 'said fulcrummember' being located on the cover to bear on the cover surface on guides for the formation of a coil of tear strip material both sides of the score lines defining the tab portion and when the lever is subsequently turned about its axis.

inwardly of the inner edge of the peripheral portion of the tear strip an amount at least equal to its breadth References Cited in me file of this pa measured in a direction toward the lifting portion, where- 5 1 UNITED STATES PATENTS by when the lever is lifted, pivoted about the fulcrum member and the lifting portion extended to the outside 3 Speidel 1938 .t 2,946,478 Cla1r et a1. July 26, 1960 of the cover .the fulcrum member 1s wholly inside the c inner edge of the peripheral portion of the tear strip with FOREIGN PATENTS 7 its ends extending outwardly 'from beneath the tab as 10 97,620 Sweden Dec. 12, 1939

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