Closure and Method for Easy Opening of Cans

An application for U.S. patent Ser. No. 908,733, filed May 23, 1978 in the names of John S. Kelley et al relates to a method of making easy-open can ends.

Easy-open can closures have been proposed in a great many different designs and constructions. In general those types which permit a closure or pull tab to be separable from a can have encountered public disfavor because of potential litter. Some can closures have been depressible into their containers and remain attached thereto; of these, various opening tabs of the pull or depressor types have been provided. The consequent arrangements have been complex and costly.

In U.S. Pat. Nos. 3,881,437 and 3,881,630, both issued in the names of Lovell and Grise, a relatively simple and economical digitally operable can end and method of making it are disclosed. Opening a can end closure according to these patents requires mere finger depression to rupture a unique weakening line. It has been found, however, that often consumers, having become accustomed to the usage of pull tabs and the like for opening purposes, are reluctant to simply apply finger pressure directly to a closure to depress it relative to a can end, apparently feeling that they might scratch a finger on a sharp edge even when no sharp edge is present. It therefore is desirable to provide, in combination with a depressible easy-open can end closure, a simple and easy-to-operate and saft-to-use opening means. Such means is proposed herein though it will be recognized as not necessarily limited to use with the Lovell-Grise closure.

It accordingly is a main object of this invention to provide an easy-open can end of the type having a closure at least partly defined by a weakening line with a simple, yet effective and safe-to-use means for manually operating the closure.

More specifically it is an object of this invention to provide a can end with a novel finger-bendable depressor for rupturing a closure portion of the end without finger contact with the closure.

To these ends, and as herein shown, there is mounted on a can end having a closure defined at least partly by a weakening line, a lever having a handle portion and a twistable depressor portion. The latter, sometimes referred to as a "gooseneck" is disposed adjacent to the weakening line when inoperative but may be lifted from the can end in a substantially 90.degree. twist about an axis generally parallel to the can end and closure thus to position an extremity or "beak" at a point of the line to be ruptured. An arcuate flange of the depressor portion is then arranged to be engaged digitally, for instance, by a thumb, and pressed toward the interior of the can. The beak consequently disrupts the weakening line at an initial point and progressively to both sides thereof as the closure is deflected into the can. The flange is stopped from entering the can by reason of an edge of the closure abutting the depressor portion. Accordingly the thumb or other digit is barred from entry and contact with sharp or rough edges. Now the handle portion may, on being urged about a pivot of the lever, swing the depressor laterally to clear the can end opening. This latter maneuver is usually optional since ordinarily the width of the depressor portion of the handle and its thickness will not afford resistance or blockage to flow of the can contents.

It is not essential to pivotally mount the lever on the can end, but when it is so secured, a small ridge or stop formation in the can end may limit rotation of the lever in one direction. A detent in the handle portion releasably mating with a corresponding protrusion in the can end may serve to initially position the lever angularly.

The foregoing and other features of the invention will now be more particularly described in connection with an illustrative embodiment and with reference to the accompanying drawings thereof, in which:

FIG. 1 is a perspective view of a typical can end having a closure defined by a weakening line, and a finger-operating means in inoperative position for opening the closure;

FIG. 2 is a view similar to FIG. 1, the opening means being shown as a lever and at its next stage wherein a depressor portion of the lever has been lifted and in part twisted to position if for disruption of the closure;

FIG. 3 is a view similar to FIGS. 1 and 2 but showing the opening lever at a subsequent stage wherein the closure has been deflected inwardly; and

FIG. 4 is a view largely corresponding to FIGS. 1-3 but showing the lever lastly shifted angularly to more fully clear the can opening.

Referring first to FIG. 1, a typical sheet metal can 10 is provided with a can end 12 which is generally planar and includes therein a closure generally designated 14. Although the latter is herein shown by way of example as being of the type disclosed in the mentioned Lovell and Grise patents and hence at least partly defined by a weakening line 16 which comprises a fractured but integral section, it is to be noted that the present invention is not limited to usage with closures of any particular type but has application to any closure defined at least in part by a disruptible weakening line however made. It will also be understood that the closure 14 is herein shown as circular for the sake of simplicity, but it need not be of any particular configuration.

As indicated by the point of an arrow A, the closure 14 may have a selected locality along its weakening line 16 whereat it is desirable to commence disruption of the sheet metal for opening the can. In many instances, including the illustrative arrangement, the selected locality is close to the rim of the can end where the sheet metal is apt to be more rigid. Substantially diametrically opposite from this locality and adjacent to the closure 14, a closure opening tab or lever 20 preferably of deformable sheet metal, for instance steel, is pivoted to the can end 12 as by a fastener such as a rivet 22. The rivet or other suitable pivotal connection enables the lever to be turned about an axis normal to the end 12 for a purpose subsequently explained. The lever comprises a depressor portion 24 to one side of the rivet, and a handle portion 26 extending on the opposite side thereof.

As shown in FIG. 1 the depressor portion 24 in its flat inoperative condition, is generally S-shaped, extends adjacent to the closure 14, and terminates in a pressure point or beak 28. It will be appreciated that the lever 20 may have other configurations for other shapes of closures to be opened thereby. A rounded flange 30 projects downwardly (as shown in FIG. 1) from a convex midsection of the depressor portion and may engage the can end to bias the beak 28 toward the point of the arrow A. As a first step in opening the closure 14, fingers may pry or seize the depressor portion 24 at the flange 30 to lift it above the can end as shown in FIG. 2. The portion 25 is accordingly twisted about 90.degree. about an axis approximately parallel to the can end in order to position the beak 28 substantially in engagement endwise with the weakening line 16 at the tip of the arrow A.

The shape and movement of the usually slender depressor portion 24 is somewhat suggestive of that of the neck of a goose. Little resistance is met in bending the portion 24 to its raised position, yet when next finger pressure is brought to bear downwardly on the flange 30 to assert force edgewise via the portion 24, the beak 28 is effective to transmit disruptive pressure on the weakening line 16 at the point of the arrow A. Continued depression of the flange 30 causes the beak to deflect the closure 14 inwardly as the line 16 is progressively broken along opposite sides from the initial rupture point. It is to be observed, though, that as indicated in FIG. 3, the flange 30 is barred from entering the can opening since an edge of the opening serves as a stop upon engaging a locality 32 on the underside of the lever 20 adjacent to the rivet 22. Accordingly, the finger which had been pushing on the flange 30 is barred from contact with an edge of the can opening.

The can top opened as shown in FIG. 3 is often acceptable for pouring out of contents without any further step. If it is desired to further clear the bent depressor portion 24 from the can opening, the handle portion 26 may be swung about the rivet axis as indicated in FIG. 4. This causes the beak 28 to move laterally to one side of the closure opening where very little if any interference is offered to pouring of the can contents.

In order to facilitate the proper angular positioning of the lever 20 on the can end 12, it may be desirable to provide a small ridge 33 in the can end to serve as a stop for a flange 34 formed on the handle portion 26. A detent 36 in the portion 26 may releasably engage a correspondingly shaped protrusion in the can end to fix the initial lever position against the ridge (not shown) as indicated in FIG. 3.

Operation of the closure opening device described will be apparent from the foregoing. In addition to being easy to use effectively, the device features both safety and low cost. Basically the user does a 1-2 step procedure: he lifts the depressor portion of the lever 20 from its flat or prone position to a raised position over the closure as shown in FIG. 2, and then pushes the depressor portion in a rocking motion downwardly. In this opening process he is first partly twisting the rather slender sheet metal neck adjacent to the rivet 20 to transfer the depressor portion from a flexible parallel relation to the can end to a stiffened normal relation thereto. Downward thrust on the flange 30 to rock the beak inwardly of the can will not buckle the depressor portion prior to the beak 28 effecting rupture along the weakening line.

It is apparent from the foregoing that the invention further provides a stackable can end which is also easily openable without endangering a finger or thumb. Moreover, since the depressor portion will be pushed into the can, no portion of the can end or its tab is likely to be broken off to be scattered.