Reusable Plastic Snap-on Closure

Abstract

A snap-on type closure which includes, generally, an annular inverted U-shaped channel about its top wall structure into which the upper edge of the open end container is received. This upper edge of the container has a bead or curl on it, and the annular outer wall of the U-shaped channel has interlocking means on its interior surface which interlock with the curl on the container to affix the closure to the container. At least one gripping and pulling handle is affixed to the annular outer wall of the U-shaped channel, for removing it. It has been found that by placing a knee on the top of the closure, gripping the bail normally provided on such containers with one hand, and the handle on the closure with the other hand, a portion of the edge of the closure can be pulled free sufficiently to break the interlocking seal, and once broken, the closure can be pulled or peeled off of the container. Thereafter, the closure can be replaced, with a resulting sealed-tight engagement which is as virtually as good as the original seal. A single handle can be provided, but a pair of handles preferably are provided. Alternatively, with a single handle, an extended interruption can be provided in the interlocking means on the closure. The second handle and/or the extended interruption permit the closure to be more easily pulled or peeled off the container.

Description

This invention relates, in general, to an improved container and, in particular, to an improved reusable plastic closure, for closing and sealing plastic containers.

The plastic closure of the present invention is of the so-called snap-on type, that is, one which is affixed to a plastic container in a fashion such as to effect a sealed-tight closure thereon, without the need of additional securement means such as, for example, a metal ring seal. Plastic closures of this type usually are provided with an annular inverted U-shaped channel about its top wall structure into which the upper edge of the open end container is received. An annular bead or curl is provided about the periphery of the upper edge of the container, and one wall of the U-shaped channel is provided with interlocking means which interlock with this bead or curl to affix the closure to the container. The U-shaped channel furthermore generally is relatively deep so that the upper edge is deeply seated therein, to effect a sealed-tight engagement. In fact, in most cases, the upper edge of the container, the bead or curl, the U-shaped channel and the interlocking means are so proportioned that one wall of the U-shaped channel must be cut or slit about its periphery, in order to break the sealed-tight engagement between the container and the closure, to remove the latter. Alternatively, some constructions are adapted to receive a tool such as a screwdriver or other special instrument beneath and between the container and the closure to effect removal.

Snap-on type closures generally are preferred over those types requiring the use of additional securement means such as ring seals, for the latter can be eliminated. This fact provides several economic advantages, including the savings in the cost of the ring seal itself and the labor costs associated with affixing it to the container. However, the fact that the closures are so difficult to remove has, to some extent, discouraged their use. The fact that the one wall of the U-shaped channel has to be cut or slit to remove the closure prevents the closure from being reused to preserve or protect the product within the container which has not been removed, and this fact has contributed greatly to the lack of acceptance of this type of closure.

Accordingly, it is an object of the present invention to provide an improved reusable plastic closure of the above-described snap-on type, for use with plastic containers.

Another object is to provide a plastic container and a snap-on reusable plastic closure which can be removed without the need of additional implements or tools, such as a screwdriver.

A still further object is to provide an improved snap-on type closure which, in accordance with a preferred embodiment, can be removed without cutting or slitting the one wall forming the U-shaped channel formed thereon.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The above objects are accomplished with a snap-on type closure which includes, generally, an annular inverted U-shaped channel about its top wall structure into which the upper edge of the open end container is received. This upper edge of the container has a bead or curl on it, and the annular outer wall of the U-shaped channel has interlocking means on its interior surface which interlock with the curl on the container to affix the closure to the container. The upper edge of the container, the bead or curl, the U-shaped channel and interlocking means, like most presently available similar arrangements, are so proportioned that considerable force or pressure must be exerted uniformly over the upper surface of the closure and particularly about its upper peripheral edge, to affix the closure to the container. In this respect, the arrangement is substantially like presently existing arrangements.

The snap-on closure of the present invention differs from these existing arrangements in that at least one gripping and pulling handle is affixed to the annular outer wall of the U-shaped channel, for removing it. It has been found that by placing a knee on the top of the closure, gripping the bail normally provided on such containers with one hand, and the handle on the closure with the other hand, a portion of the edge of the closure can be pulled free sufficiently to break the interlocking seal, and once broken, the closure can be pulled or peeled off of the container. Thereafter, the closure can be replaced, with a resulting sealed-tight engagement which is as virtually as good as the original seal.

A single handle can be provided, but as explained more fully below, a pair of handles preferably are provided. Alternatively, with a single handle, an extended interruption can be provided in the interlocking means on the closure. The second handle and/or the extended interruption permit the closure to be more easily pulled or peeled off the container.

The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a top plan view of a closure exemplary of the invention;

FIG. 2 is a side plan view of the closure of FIG. 1;

FIG. 3 is a partial bottom plan view of the closure of FIG. 1;

FIG. 4 is a partial sectional view illustrating the manner in which the closure and the container interlock to effect a sealed-tight engagement; and

FIG. 5 is a plan view illustrating the manner in which the closure is removed from the container.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to the drawing, in FIG. 5 there is illustrated an open end container 10 having a bottom wall 11 and side wall 12. A pair of bail flange supports 15 (only one of which is shown) are provided on the side wall 12 in diametrically opposed positions, for supporting a wire bail 14. This open end container 10 can be of metal or plastic, and of a type having a bead or curl 19 (FIG. 4) provided about the peripheral edge of the side wall 12 at the open end of the container. In this respect, the container 10 is of a generally standard construction. As indicated above, the invention is particularly directed to plastic containers and closures, however, the container could be of metal.

The container 10 is sealed, by means of a plastic closure or lid 13. This closure 13 has a top wall 21 and a inverted U-shaped channel provided at the periphery of the top wall 21 formed by an annular outer wall 22 and a concentric inner wall 23, with a top section 24 connecting them. Interlocking means in the form of an annular bead 28 is provided on the interior surface of the annular outer wall 22, which bead 28 interlocks with the bead or curl 19 on the container to affix the closure 13 to the container 10, as described more fully below.

An upstanding annular support rib 25 (FIGS. 1 and 4) provides additional rigidity to the closure 13, and this support rib 25, as can be best seen in FIG. 4 extends downwardly beneath the top wall 21 and terminates in a curved section which merges with the annular inner wall 23, thereby forming a U-shaped channel 27. Within this U-shaped channel 27 there are provided a number of ribs 31 which provide additional support and rigidity to the closure 13. A number of stress relieving grooves 33 also are provided centrally of the top wall 21 of the closure.

The closure 13 as thus described is substantially similar to presently available snap-on type closures and, as indicated above, a sealed-tight engagement with a container normally is effected by forcing the peripheral edge of the open end of the container within the U-shaped channel of the closure, until the bead or curl 19 on the container interlocks with the bead 28 on the annular outer wall 22. The container and the closure normally are proportional such that the peripheral edge of the container is deeply seated within the U-shaped channel, and such that a substantial force or pressure must be exerted on the closure to forcibly urge the peripheral edge of the container into the U-shaped channel. In fact, the force or pressure required normally is of such magnitude that the closure cannot be fitted thereon by hand, and a mallet or the like or a machine must be used. In a production-type operation, the closure normally is loosely seated in position on the container, and both then are positioned within a press including a hydraulic cylinder having a circular-shaped pressing disc of a diameter slightly larger than that of the closure affixed to its piston. Upon operating the hydraulic cylinder, the pressing disc engages the closure and forcibly urges it into sealed-tight engagement with the container.

Normally, as indicated above, snap-on closures of this type are removed by first cutting or slitting the annular outer wall 22 in a number of places about its periphery or, alternatively, the closure is designed to receive a special tool for effecting the removal. In the instant case, the closure 13 is provided with at least one handle 36 which is integrally formed with the annular outer wall 22, along its lower edge. The handle 36 has a hand-opening 37 in it, to permit it to be easily gripped.

To remove the closure 13, the handle 36 is gripped with one hand and the wire bail 14 is gripped with the other to hold the container 10. Then, the handle 36 is simultaneously pulled upwardly and rearwardly. Preferably and advantageously the knee is placed in the center of the closure 13 while pulling on the handle 36, as generally illustrated in FIG. 5. In pulling the handle 36 upwardly and rearwardly, the handle being affixed to the lower edge of the annular outer wall 22 functions much like a lever would when used to pry the closure loose to remove it. In pulling the handle 36 upwardly and rearwardly, the interlocking seal between the bead or curl 19 and the bead 28 is broken about a small portion of the lower end of the annular outer wall 22. Initially, a fairly substantial force is required to break the interlocking seal, but once it is broken, the closure 13, because of its resiliency or flexibility, will bend upwardly and a progressively larger portion of the interlocking seal is pulled or peeled free, as the same force is exerted on the handle, until the closure is entirely removed.

While the closure 13 can be removed with the use of only a single handle 36, it is preferred to provide at least two handles. This second handle can be diametrically opposite the handle 36, as in the case of the handle 38 shown in phantom in FIG. 1, and in such cases, first one then the other handle is manipulated in the manner described above, to effect removal of the closure. Preferably and advantageously, however, the second handle is radially displaced only within a range of 90.degree. from the first handle, a preferred radial displacement being within a range of 30.degree. to 45.degree. from the first handle, as in the case of the handle 39 shown in phantom in FIG. 1.

If the two handles are diametrically opposite one another, there is a tendency to use these handles to carry the containers. In view of the weight of these containers when filled, the possiblity exists that the closure may be accidentally dislodged, either completely or partially, in which case the product may be spilled or caused to deteriorate if the air-tight seal is broken. Accordingly, it is preferred to discourage the use of the handles being used to carry the container. By offsetting the handles at an angle less than 180.degree., preferably 90.degree. or less, the container is extremely ackward to carry by means of the handles, because of the resulting unbalanced condition.

Also, when the closure is removed using only one handle, such as the handle 36, it is found that the closure will bend and the interlocking seal will disengage relatively easily until a portion of the periphery of the closure extending approximately 20.degree.-30.degree. radially on each of the opposite sides of the handle are free. At this point, there is a tendency for the closure to "hang-up," or stick, for further bending of the closure tends to resist the releasing action of the interlocking seal. The closure, of course, can be completely removed simply by exerting a sufficient force to overcome this resistance, but a second handle properly positioned permits the closure to be removed far more easily.

The second handle therefore preferably and advantageously is radially displaced from the first handle at or approximately at the location on the annular outer wall 22 where the closure 13 bends and tends to resist the releasing action of the interlocking seal. As indicated above, this location is approximately 20.degree. to 30.degree. radially displaced on one side or the other of the first handle.

With the second handle located as described above, the closure 13 is removed by first manipulating the first handle until further removal is resisted. Then, the second handle is manipulated to complete the removal. By being positioned at the location where the closure binds and hence resists removal, pulling on the second handle exerts a force on the closure at the location of the binding. The resistance, therefore, is lessened, and less force therefore is required to remove the closure.

The closure 13 can be made more easily removable, without any substantial sacrifice to the seal between the closure and the container, by providing extended interruptions 41 and 42 in the annular bead 28 on the interior surface of the annular outer wall 22. These interruptions 41 and 42 can be used in combination with a second handle, however, they can be used as an alternative thereto. These interruptions 41 and 42, like the second handle, preferably and advantageously are positioned to be radially displaced within a range of 30.degree. to 45.degree. from the handle 36, on each of the opposite sides of the latter, at the location where there is a tendency for the closure to "hang-up," or stick, during removal. By eliminating the annular bead 28 at these locations, the closure is automatically released since there is no interlocking between the closure bead 28 and the curl 19, hence the resistance to removal is eliminated. These interruptions 41 and 42 should be approximately 1 inch to 2 inches in length, to effect the release.

Once the closure 13 is removed, it can be used to reclose the container 10, since the annular outer wall 22 is in tact, not having been cut or slit to effect removal of the closure, as in the past.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description are efficiently attained and certain changes may be made in the above article. Accordingly, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

Now that the invention has been described, what is claimed as new and

1. In combination with an open end container having at its open end a bead-like curl extending about the periphery of the upper edge of its side wall: a snap-on plastic closure adapted for removable replacement over the open end of said container comprising a center top wall structure, a perimetrical inverted U-shaped channel provided at the periphery of said top wall structure; said U-shaped channel being formed by an inner and a concentric outer annular wall and a top section interconnecting the inner and outer walls; at least one handle integrally affixed to the lower edge of said annular outer wall and extending downwardly as an extension thereof; and interlocking means formed on the interior of said outer annular wall and lockingly engaged beneath said bead-like curl to provide an interlocking seal between them to removably secure said closure over the open end of said container, said interlocking means extending substantially completely about the interior of said outer annular wall and having at least two extended interruptions therein each within a range of length so as not to cause any substantial sacrifice to the seal between the closure and the container and each radially displaced within a range of 30.degree. to 45.degree. on opposite sides of said handle, said handle when pulled upwardly and rearwardly with said container held stationary functioning as a lever to break said interlocking seal and thereafter as said handle is pulled to remove said closure from said container, said interruptions substantially eliminating the tendency of said closure to "hang-up" or stick during removal, whereby said closure can be removed without the need of additional implements and without first having to cut or slit said annular outer wall about its periphery.