Plastic and Fiber Container

This invention relates to containers and, more particularly, to a plastic and fiber container.

In one form of conventional shipping and storage container, a tubular side wall is formed of fibrous material or other material. Conventionally, metal retaining rings are provided at opposite ends of the side wall for securing closure walls there across. Such metal retaining rings are relatively costly and heavy and are not fully satisfactory in the formation of a low cost shipping and storage container.

Ultimately, the container may be sent to, for example, an incinerator for destruction. If a metal retaining ring is used, then it is necessary to remove the metal from the incinerator.

Further, in the formation of such a prior container, a rolling operation is required to seal the retaining ring to the drum.

An alternative to such prior containers is described in my U.S. Pat. No. 4, 805,798, which discloses a container in the form of a tubular fiber sidewall having a connecting ring molded of synthetic resin in situ in association with an end portion of the sidewall. Such a container requires a die press adapted to support the sidewall while molding the connecting ring to the sidewall.

The present invention is directed to solving one or more of the problems discussed above in a novel and simple manner.

In accordance with the invention, there is disclosed a closure adhered to a sidewall by vibrational welding.

Broadly, there is disclosed a container comprising a tubular sidewall defining a peripherally enclosed space, the sidewall having an annular end portion defining an open end of the space. The end portion is provided with through openings spaced circumferentially about the open end. A plurality of blocks of a synthetic resin of a size and shape corresponding to a size and shape of the sidewall through openings are retained therein. A closure of synthetic resin has a U-shaped annular connecting portion receiving the end portion of the sidewalls. Means are provided for securing the sidewall to the closure by vibrationally welding the connecting portion to the blocks.

In accordance with one aspect of the invention, the closure has a transverse center wall closing the end of the space and connected at its peripheral edge to the connecting portion.

It is a feature of the invention that the openings are spaced equidistantly from a distal end of the sidewall end portion.

It is another feature of the invention that the blocks comprise generally planar blocks having a plurality of raised portions to facilitate vibrational welding to the connecting portion.

It is still another feature of the invention that the blocks comprise generally planar blocks having a plurality of raised ridges on opposite sides to facilitate vibrational welding to the connecting portion.

It is still another feature of the invention that the securing means secures the sidewall to the closure by ultrasonically welding the blocks into the connecting portion.

There is further disclosed herein a method of assembling a container, which comprises providing a tubular sidewall open at one end and including a plurality of circumferentially spaced openings through the sidewall proximate the open end, inserting a block of synthetic resin into each sidewall opening, inserting the open end of the tubular sidewall into an annular channel of a U-shaped closure connecting portion of synthetic resin so that the blocks are entirely received in the channel, and vibrationally welding the closure channel to the blocks to secure the sidewall to the closure.

In the illustrated embodiment, the closure may take one of two forms and is formed of a molded synthetic resin. In one form, the closure includes a transverse center wall connected at its peripheral ridge to a connecting ring. In another form, the closure comprises a connecting ring vibrationally welded to the sidewall. The connecting ring is used in connection with a removable cover for closing the one end of the tubular sidewall. The connecting ring includes a radially outwardly opening annular recess and the closure is removably mounted to the connecting ring by a portion thereof removably interlocked with the connecting ring in the recess.

Further features and advantages of the invention will readily be apparent from the specification and from the drawings.

FIG. 1 is a partial, exploded view of a container in the form of a fiber and plastic drum in accordance with the invention;

FIG. 2 is a perspective view of a tubular sidewall for the container of FIG. 1;

FIG. 3 is a partial, perspective view illustrating a connecting block insertable into a through opening in the sidewall of FIG. 2;

FIG. 4 is a plan, sectional view providing a similar representation to that of FIG. 3;

FIG. 5 is a perspective view of the connecting block of FIG. 3;

FIG. 6 is a side view of the connecting block of FIG. 5;

FIG. 7 is a sectional, exploded view illustrating insertion of the sidewall into a connecting ring;

FIG. 8 is a sectional view showing the sidewall inserted in the connecting ring;

FIG. 9 is a sectional view illustrating the securing of the sidewall to the connecting ring as by vibrational welding; and

FIG. 10 is a partial, sectional view illustrating the fully assembled container according to the invention.

As illustrated in the drawing, a container 20 includes a fibrous tubular sidewall 22. The sidewall 22 defines a right cylinder, it being understood that the sidewall 22 may define other suitable configurations, such as square, oval, etc.

With reference also to FIG. 2, the sidewall 22 includes a lower end portion 24 and an upper end portion 26 and defines an internal storage space 27. The space 27 is closed at a lower end by a bottom closure 28 fixedly secured to the sidewall lower end portion 24, as seen in FIG. 1. The upper end of the space 27 is selectively closed by a second closure comprising a cover 30 removably secured to a chime or connecting ring 32 fixedly secured to the sidewall upper end portion 26.

As seen in FIG. 2, the sidewall lower end portion 24 is provided with an array of through openings 34 adjacent a distal edge 36 thereof. The openings 34 are square in shape and are equidistantly circumferentially spaced about the sidewall lower end portion 24.

Similarly, the sidewall upper end portion 26 is provided with an array of through openings 38 adjacent a distal edge 40 thereof. The openings 38 are equidistantly circumferentially spaced about the sidewall upper end portion 26.

The openings 34 and 38 may be on the order of, for example, one inch square and spaced one inch apart. Further, the openings 34 and 38 may be on the order of 1/4 inch spaced from the respective distal edge 36 and 40.

With reference to FIGS. 1 and 7, the connecting ring 32 is molded of a suitable synthetic resin, such as high density polyethylene The connecting ring 32 is a U-shaped annular ring defining an annular, downwardly opening channel 42. The connecting ring 32 is of a size so that the sidewall upper end portion 26 is receivable therein with the connecting ring 32 entirely covering the through openings 38, as illustrated in FIG. 8. Particularly, in the exemplary embodiment the depth of the channel 42 is at least 1-1/4 inches to account for the one inch square opening 38 being spaced 1/4 inch from the distal edge 40.

To secure the connecting ring 32 to the sidewall upper end portion 26, a plurality of connecting blocks 44 are provided, one for each opening 38. Each connecting block 44 is of a size and shape corresponding to that of the opening 38. In the illustrated embodiment, each block is one inch square with a thickness corresponding to the thickness of the sidewall 22. The blocks 44 are formed of synthetic resin. The block 44 includes opposite planar sides 46, each having three parallel elongate ridges 48. Each ridge 48 may be on the order of 0.025 inches in height with the distal edge 50 of each ridge defining a right angle.

A block 44 is inserted in each opening 38. The blocks 44 are retained therein as by a friction fit Subsequently, the sidewall upper end portion 26 is inserted into the connecting ring channel 42, as illustrated in FIG. 8, with the blocks 44 entirely covered within the channel 42.

The connecting ring 32 is secured to the sidewall 26 by vibrationally welding the blocks 44 to the connecting ring 32 in the channel 42. Particularly, the sidewall 26 is placed over a cylindrical fixture 52, see FIG. 9, which provides a backing against the connecting ring 32. A sonic welding apparatus 54 is placed against the connecting ring 32 opposite the fixture 52 to sonically weld each block 44 to the connecting ring 32 to provide a complete mechanical connection without use of adhesives or the like. Particularly, the welding apparatus 54 is vibrated at ultrasonic frequencies transferred to the connecting ring 32. The vibrations are transmitted through the connecting ring 32 to the joint area with the block 44 where it is converted to heat through friction that melts the plastic. Initially, the ridge edge 50 concentrates the energy to rapidly initiate the softening and melting of the joining surface. This provides rapid welding while achieving maximum strength. After welding, the parts become integral such that the block 44 connects the opposite walls of the connecting ring through the openings 38, as particularly illustrated in FIG. 9.

The connecting ring 32 further includes a peripheral, radially outwardly opening annular recess 46. The cover 30 includes a transverse center wall 48 and a peripheral depending wall 50. The wall 50 includes a radially inwardly projecting flange 52 receivable in the connecting ring recess 46 to be retained thereon.

The bottom closure 28 comprises a unitary element molded of a suitable synthetic resin, such as high density polyethylene. The closure 28 comprises a transverse center wall 54 connected at its peripheral edge 56 to a connecting ring 58. The connecting ring 58 is similar to the connecting ring 32, discussed above, i.e. has a U-shaped annular configuration.

The bottom closure 28 is secured to the sidewall 22 similar to the connecting ring 32. Particularly, a plurality of plastic blocks 44 are inserted into the openings 34. The sidewall lower end portion 24 is then inserted into a channel 60 in the connecting ring 58. Although not specifically illustrated, the blocks 44 are vibrationally welded at ultrasonic frequencies to the connecting ring 58 to provide a securement as illustrated in FIG. 10.

Thus, in accordance with the invention, a container 20 is provided consisting of two component elements, namely plastic and fiber. After the container 20 has completed its useful life, the plastic and fiber parts can be separated and recycled, as necessary. No rolling operation is required to connect a metal ring to the container 20, and no metal remains at the completion of the useful life of the container 20.

The container 20 provides positive securement of the closures 32 and 28 to the sidewall 22 without having to mold the same directly thereon. Moreover, this such securement is accomplished without the use of a glue or other type of adhesive. Such a connection does not loosen at high temperatures, such as can happen with glue, is not messy or toxic such as certain glues, and does not react with the contents stored in the space 28.

The disclosed embodiment of the invention is illustrative of the broad inventive concepts comprehended.