US3805993A - Closure for metal container - Google Patents

Abstract

A metal container having an open top and a sealed bottom panel; the open top of the container is defined by a peripheral flattened bead constructed to receive a closure which is comprised of an innerseal membrane adhesively affixed to the peripheral bead and detachably bonded to a reinforcing backing to form a liner overlayed by a protective plastic snap-on cap which snugly grips the bead and is capable of acting as a reclosure after the innerseal is ruptured or removed.

Description

United States Patent Enzie et a1.

[ Apr. 23, 1974 CLOSURE FOR METAL CONTAINER [75] Inventors: William H. Enzie, Indianapolis. Ind.; Norman A. Vanasse, Mahwah, N.J.; Gerald T. Tracy, Stamford; H. T. Easton, Greenwich. both of Conn.

[73] Assignee: General Foods Corporation, White Plains, NY.

[22] Filed: Apr. 14, 1970 [21] Appl. No.: 28,330

[52] US. Cl 2.20/60 R, 215/40, 220/29 51] Int. Cl... 365d 43/10, B65d 51/18, B65d 53/00 [58] Field of Search 220/60 R, 29; 215/40 [56] References Cited UNITED STATES PATENTS 2.019.376 10/1935 Wilhc1m....... 220/60 R UX 3.329.295 7/1967 Fields 215/40 3.425.388 Z/l969 Wcst.... 220/60 R X 742,325 10/1903 Hull 220/60 2.646.183 7/1953 Pellelt 215/40 2.937.481 5/1960 Palmer 215/40 UX 2.946.471 7/1960 Randlett 215/40 X 3.059.800 10/1962 Mills 215/40 X 3.081.904 3/1963 Pipes 220/60 3,330,720 7/1967 Stevens et a1 215/ X 3,333,728 8/1967 Burdick, Jr... 220/ X 3,367,665 2/1968 Gorman 220/60 X 3,480,177 11/1969 Elliot 220/60 X 3,501,042 3/1970 Risch et a1. 215/40 3.550.803 12/1970 Pelli 215/40 X FOREIGN PATENTS OR APPLICATIONS 317.397 1/1957 Switzerland 220/60 R 6.502.693 9/1966 Netherlands 220/29 Primary Examiner-George E. Lowrance Assistant Examiner-Allan N. Shoap Attorney. Agent, or FirmHoward J. Newby; Bruno P.

Struzzi; Daniel .1. Donovan [57] ABSTRACT A metal container having an open top and a sealed bottom panel; the open top of the container is defined by a peripheral flattened bead constructed to receive a closure which is comprised of an innerseal membrane adhesively affixed to the peripheral bead and detachably bonded to a reinforcing backing to form a liner overlayed by a protective plastic snap-on cap which snugly grips the bead and is capable of acting as a reclosure after the innerseal is ruptured or removed.

10 Claims, 3 Drawing Figures CLOSURE FOR METAL CONTAINER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates, in general, to closures for containers and, in particular, is directed to an easy-opening plastic-type closure assembly for sealing a can-type container and adapted to serve as a reclosure.

2. Description of the Prior Art For the most part, metal containers of the prior art and especially metal containers of the tin can" type are sealed at both top and bottom ends with metal panels. The metal end panels are usually secured to the wall of the container by a combination of crimping and soldering operations. The great majority of containers of this type, especially those containers designed for hermetically packaging foodstuffs for household use,

are opened by cutting away one end panel or by tearing away a portion of the metal of the container along prescored lines.

Within recent years, it has been the practice to include with many of the metal containers a plastic overcap which fits snugly over the end of the container and, being removable and replaceable, is used as a reclosure device after one metal end panel of the container has been removed and discarded.

Although all-metal containers have pronounced advantages, such as excellent structural strength, the capability of hermetically sealing the packaged contents, and the capability of withstanding retorting processing conditions, such containers are relatively expensive to manufacture compared to the cost of manufacturing paper-type containers. Another drawback of the allmetal can is manifest in the difficulty of opening the scaled metal end a chore which, at times, cannot only be troublesome, but also dangerous.

In view of the large number of all-metal containers employed to package foods and other materials, an incremental cost reduction in manufacturing the container would result in an overall large monetary savings. Also, since many materials which do not need all of the protection afforded by all-metal containers are, nevertheless, packaged in containers of this type, there has existed an additional incentive to develop a container sufficiently adequate to effectively protect these materials at a lower cost; that is, a container having many of the attributes of an all-metal container plus the distinct advantage of being more easily opened for access to the contents and, importantly, less costly to manufacture. i

The recent achievement of manufacturing a degassed roasted and ground coffee as disclosed in US, Ser. No. 878,230, assigned to the same assignee as the present application, wherein the coffee does not release excessive amounts of gas after packaging has added further impetus to the development of a more economical metal container with an easy open reclosable closure and with only those features of an all-metal can which are essential for adequately protecting its contents.

SUMMARY OF THE INVENTION Briefly stated, the present invention comprehends a metal container, one end of which is closed and sealed with a conventional metal end panel, and the opposite end (top) closed and sealed with a closure comprising a paper-type innerseal membrane protected with a pulpboard-type liner and a plastic reclosure cap.

The container of this invention is more economical to manufacture than one having both ends closed and sealed with conventional metal end panels, and is intended to satisfy the packaging requirements for a large variety of foodstuffs, pharmaceuticals and like materials.

The container of this invention has surmounted a major difficulty usually associated with the use of flexible membrane seal structures. Surprisingly, it has been found that the container of the invention does not dent in the flexible membrane seal area when subjected to a sharp blow. Instead, the plastic overcap acts as a cushion to prevent denting and leakage of the seal. Also, the sealing membrane, being a flexible material, can distort and maintain its seal if the top of the container is subjected to abusive forces on its side which cause the can to take on an out of-round shape.

Accordingly, it is an object of this invention to provide a container and closure for same which can be employed for packaging comestibles, such as soluble coffee powder and degassed roasted coffee wherein the food is packaged in an atmosphere of carbon dioxide, nitrogen or other inert gas.

It is another object of this invention to provide a metal container-closure combination which offers the distinct consumer advantage of being easy to open.

It is another object of this invention to provide a metal container with an improved tamper-proof closure feature.

It is a further object of this invention to provide a container which has superior structural strength with respect to wall collapse or deformation proximate the open end of the container.

It is still another object of this invention to provide a container having a plastic overcap in which the outer diameter of the plastic overcap covering the top of the container is the same as the outer diameter of the bottom end of the container. Thus, side-by-side cans touch at top and bottom simultaneously so that the top seal area is protected from excessive distribution abuse by the can-to-can contact of bottom-to-bottom. Additionally, with both top and bottom diameters of the container assembly, including the plastic overcap, being the same, the can structure provides for smaller size cases, easier casing of cans and a better shipping unit than that provided with the conventional metal cans when both metal ends have the same diameter, and the addition of the snap on plastic overcap makes the top end larger in diameter than the bottom end.

The objects of the invention are accomplished with a metal container whereof the annular wall has a radially outward projecting bead and the wall, above the bead, is necked inwardly and terminates at the open end in a flattened rolled bead constructed to adhesively receive an innerseal. The innerseal is weakly bonded to a reinforcing backing. The laminate of innerseal and reinforcing backing form a substantially impermeable closure liner for a plastic snap-0n overcap which snugly grips the outer peripheral surface of the bead of the container.

The essence of the invention resides in the unique configuration of the bead surmounting the annular wall at the open end of the can. The rolled flattened bead serves to present a sufficient amount of flat surface contact area for adequately securing the innerseal thereto with an adhesive sealant.

The flat bead also reinforces the annular wall of the metal container at the proximity of the closure end against distortion from radially directed forces and compensates for the loss of any such support created by the substitution of the conventional metal end panel with the resilient closure of the invention. Also, by forming the flat bead with its rolled edge surface projecting radially outward from the indented wall of the container, the bead acts as an excellent gripping surface for the snugly fitting radially depending skirt of the plastic overcap and; additionally, serves to insure a clearance between the skirt of the overcap and the wall of the container, thereby facilitating finger gripping of the skirt for removal of the overcap from the container.

Th foregoing and additional objects and features of this invention will become more fully apparent from the following detailed description of the construction of the open-top can and the plastic closure when taken into consideration with the figures of the drawing wherein like reference characters are employed to designate like part in the application and throughout the several views.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of a container and closure of the invention.

FIG. 2 is an enlarged fragmentary vertical sectional view of FIG. 1 taken through an end portion of the can body illustrating the closure as applied to the flattened rolled bead of the can.

FIG. 3 is a view similar to that of FIG. 2 showing an optional, further tamper-proof version of the closure.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now tothe drawing in detail, it will be seen that there is illustrated in FIG. 1 a container body constructed with a welded seam (11) and having a conventional bottom metal end panel (13). The top of the container is provided with the closure assembly of the invention shown generally as numeral (12). The wall (28) of the container body (10) is formed so as to have a radially outward projecting bead (28A) to which, in one preferred embodiment of the invention, a portion of the closure assembly (12) is in compressible contact as will be described hereinafter.

As shown in greater detail in FIG. 2, the closure (12) is comprised of a membrane innerseal (14) which is laminated to a reinforcing backing (16) to form a liner (40) for the plastic overcap (18). The laminate of innerseal and reinforcing backing is supported in place in the plastic overcap by means of the recess (24) and the beveled circumferential shoulder (20) formed in the upper portion of the depending skirt (22) of the plastic overcap (18).

The innerseal is laminated to the reinforcing backing by any of well-known methods, such as that disclosed in Pellett U.S. Pat. No. 2,646,183. As in standard practice, the inner-seal (14) is detachably laminated to the reinforcing backing (16) with a weak bond which will permit the backing to break away from the innerseal incident to removal of the closure from the container.

In practice, the laminated liner (40) is pressed into the overcap (18) past the shoulder and into the internal peripheral recess (24) of the skirt (22) of the resilient plastic overcap (l8) and is held in place by the contraction of the skirt and the upper shoulder (20) formed therein. The laminated liner and overcap are, therefore, preassembled and applied to the can as a single unit in one closure operation. When the plastic overcap is removed from the container, the projecting shoulder (20) abuts the backing (l6) and the backing is, therefore, removed with the overcap.

The upper wall end (28) of the container (10) is indented above the radially outward projecting bead (28A) and further indented (26) as shown in FIG. 2, and rolled into a flattened bead shown generally as numeral (30). The bead (30) has a substantially flat surface portion or flange (30A) which extends radially outward of the wall (28) of the container and is disposed normal to the axis of the can body. Continuous from the outer periphery of the flange (30A), the bead is rolled to form a depending arcuate or bight portion (30B) and terminates with the edge (30C) of the metal disposed beneath the flange (30A) of the bead.

The lower face of the innerseal (14), is received by the flat portion or flange (30A) of the bead (30) when the closure is applied to the open end of the can (10), Prior to applying the closure assembly, the flat portion of the bead is coated with an adhesive sealing and, as the closure assembly is pressed onto the bead, it is rotated slightly to impart uniform distributionof the sealant and insure maintenance of the inner seal during and after removal of the plastic overcap and the reinforcing backing. The extensive surface area presented by the unique flat configuration of the bead (30) of the invention to the innerseal establishes sufficient contact area to insure an excellent bond between innerseal and bead; a bond which is stronger than the bond between the innerseal and the reinforcing backing. Therefore, when removing the closure assembly, the reinforcing backing, which is retained in the plastic overcap is pulled away from the innerseal. The intact innerseal remains adhered to the bead of the container and may then be ruptured or removed when it is desired to gain access to the contents of the container.

Once again referring to FIG. 2, it can be seen that the arcuate portion (308) of the bead (30) depending from the outer periphery of the flange (30A) of the bead is surrounded by the skirt (22) of the overcap. The skirt is formed with a second, lower shoulder (32) which underlies the portion of the bead inwardly directed beneath the flange. Thus the frictional grip between the inner wall of the depending skirt (22), including the shoulder (32) formed therein, and the bead surface (308) extending from the flange of the bead retains the overcap in place across the top of the container.

The arcuate or curl portion (30B) of the bead (30) has a diameter equal in length to the height of the reof the wall (28) of the container to provide a clearance between the lower portion of the overcap depending skirt (22A) and the container wall (28). The clearance so provided facilitates finger gripping the skirt to remove the plastic overcap (and the reinforcing backing) from the container.

Once the plastic cap is removed, the innerseal is easily ruptured and peeled from the bead for access to the contents and reclosure is effected by snapping the plastic overcap over the bead.

FIG. 3 illustrates an alternate modification of the plastic overcap construction of the invention. As shown in FIG. 3, the depending skirt of the overcap is extended to form a thin section (223) which is in tight compressible contact with the radially outward projecting bead (28A) circling the wall (28) of the container. The thin extension of the skirt must be torn away in order to provide sufficient space below the remaining skirt in order to remove and grasp the overcap. The skirt extension (223) renders the closure assembly further tamper-proof by requiring the user to tear away a visually exposed portion of the closure in the process of removing the overcap from the container.

In practicing the invention, a variety of sheet materials are used for the innerseal membrane depending principally on the degree of impermeability required. Plastic, glassine, and foil laminate innerseals have been employed with the foil laminated innerseal providing the best degree of moisture and gas impermeability.

The reinforcing backing, which together with the innerseal membrane forms the liner for the plastic overcap, can be constructed of pulpboard, newsboard, or plastic having a thickness ranging from about 0.035 inch to about 0.050 inch. The important criterion with respect to the backing is that it need be sufficiently resilient and compressible only to the extent to effect proper cushioning when the closure is applied to the container bead flat surface. The reinforcing backing should have sufficient stiffness to remain held within the recess of the plastic overcap when the overcap is removed from the container.

The primary purpose of the reinforcing backing is to serve as a convenient means to assemble the liner material (paper-thin inner membrane seal adhered to backing) onto the plastic overcap and waxed pulpboard is usually employed because of its low cost and ease of adhering a removal inner seal and insertion into the overcap with high speed assembly equipment The plastic overcap (also referred to as a snap-on lid) can be made from injection-moulded or sheet-formed high impact strength polystyrene or low density polyolefines.

In the manufacture of the plastic overcap, it is customary to mold the overcaps and to cull-out those which are warped. Warped overcaps can be produced by any one of a combination of many process variables in their normal manufacture. Warped overcaps are usually produced when the horizontal wall thickness becomes too thin in relation to the vertical wall (skirt) thickness. Surprisingly, it has been found that such warped liners can be used on the container of the invention providing the innerseal and reinforcing backing are assembled immediately after molding, in which case the liner and backing take the warp out of the overcap, or make it flat again as a result of adding rigidity to the overcap.

Also, because of the reinforcing backing, it is possible to mold the overcap with a very thin clear top wall, which both reduces the cost of the overcap through the use of less plastic raw material, and improves the clar- 5 ity for viewing a sales message printed on the top of the backing and for viewing the contents of the container after the backing is removed from the plastic overcap.

The innerseal is wax laminated to the reinforcing backing and is either coated with a pressure-activated sealant for adherence to the flat flange of the container bead or can be sealed with glue, hot melt, latex or induction sealing methods.

Thus, the number of combinations of innersealing, backing, overcap, and adhesive materials which can be used in the closure constructions of this invention are numerous.

Although the reinforcing backing can accommodate minor irregularities in the flat surface flange of the container bead when the closure assembly is pressed onto the container, and thus assure a continuous sealing, it has been found preferable to weld the seam of the container body wall.

Since the top end (open end) of the container is indented for about the upper one-half inch and the bead is rolled to form a flat surface or flange having a width ranging from about 0.04 inch to about 0.08 inch, welding of the metal container body seam is required, in most instances, to prevent a major irregularity such as a bump on the flat surface of the bead and to permit indenting the top end of the container without fracturing the seam.

The container closure combination of this invention lends itself to the packaging of many foods, drugs, and like materials for household consumption, including soluble coffee and recently developed degassed roasted and ground coffee. The commercial packaging of high quality soluble and degassed" roasted and ground coffee entails packaging the coffee in an inert gas atmosphere usually nitrogen or carbon dioxide. The inert gas at approximately atmospheric pressure, acts to block or otherwise prevent air from outside the container pentrating the substantially impermeable innerseal membrane, to come into contact with the packaged coffee being protected until the closure has been opened and the innerseal membrane ruptured.

In summary, the point of novelty of the invention resides in the unique characteristic of the flange particularly adapted to receive a substantially impermeable membrane together with protective closure elements and, as a result, effects an economical container especially suitable for the packaging of soluble coffee and degassed roasted and ground coffee wherein their high quality aroma and flavor are protected by an inert gas atmosphere. I

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the preferred embodiments are, of course, subject to modifications. Variations in container shapes providing square or rectangular shaped open ends and closures could be employed without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the invention to the particular embodiments illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

What is claimed and desired to be secured by Letters Patent is:

1. In combination, a container and closure device,

a. said container comprising,

1. a metal annular body wall,

2. a metal bottom end panel connected integrally with the body wall,

3. a radially outward projecting first bead formed in the body wall proximate the end of the wall distal the bottom end panel,

4. an inwardly projecting section of body wall above the first bead, and

5. a second bead member defining an opening in the container, said second bead member having an inwardly indented arcuate portion, a flat flange surface normal to the body wall and projecting radially outward therefrom, and an arcuate portion depending from the outer periphery of the flange surface and terminating inwardly beneath the flange surface;

b. said closure device comprising,

2. a membrane-type inner seal, the lower surface of said inner seal adhered along its periphery to the flat surface portion of the second bead member and the upper surface of the inner seal adhered to 2. a reinforcing backing member, and

3. a flexible plastic overcap constructed to provide a snapping-type cap for the container, said overcap having a panel portion and a peripheral depending skirt surrounding the panel portion, said peripheral depending skirt terminating in a shoulder portion which underlies the portion of the second bead member inwardly directed beneath the flange surface thereof and said skirt having an internal peripheral recess proximate the panel within which said inner seal and backing member are press-fit secured, said recess being equal in height and diameter to the arcuate portion of said second bead member,

wherein the second bead member projects radially from the upper section of the body wall a distance sufficient to i. provide clearance between the plastic overcap slirt and the container wall when the plastic overcap is received by the bead member as by snapping the plastic overcap over the bead member, the clearance being of sufficient magnitude to facilitate finger-gripping the skirt to remove the flexible plastic overcap and reinforcing backing member from the container and concomitantly 2. cause the received plastic overcap to extend radially a distance substantially equal to the radial dimension of the bottom closed end of the container, and

3. with the inner seal and reinforcing backing members removed from the plastic overcap, to receive the plastic overcap by pressed-fitting in the recess in the peripheral skirt, thereby providing a combination in which the plastic overcap securely recloses the container both with and without the reinforcing backing member and adhered membrane-type inner seal.

2. The combination of claim 1 further characterized in that the innerseal membrane is glued to the bead.

3. The combination of claim 1 further characterized in that the innerseal membrane is heat sealed. to the bead.

4. The combination of claim 1 further characterized in that the innerseal membrane is of the pressureactivated adhesive type.

5. The combination of claim 1 further characterized in that the innerseal membrane material of construction is selected from the group consisting of glassine, plastic, and foil laminate.

6. The combination of claim 1 further characterized in that the resilient backing material of construction is selected from the group consisting of pulpboard, newsboard and plastic.

7. The combination of claim 1 further characterized in that the plastic cap material of construction is a thermal plastic resin.

8. The combination of claim 1 further characterized in that the plastic cap material of construction is polystyrene.

9. The combination of claim 1 further characterized in that the plastic cap material of construction is a thermal plastic polyolefine.

10. The combination of claim 1 further characterized in that the peripheral skirt of the plastic overcap is formed with an extended section which snugly grips the container wall after the plastic cap has been received by the bead, thereby preventing removal of the plastic cap from the container until the extended section of the skirt is torn away from the container.

Claims (19)

1. In combination, a container and closure device, a. said container comprising, 1. a metal annular body wall, 2. a metal bottom end panel connected integrally with the body wall, 3. a radially outward projecting first bead formed in the body wall proximate the end of the wall distal the bottom end panel, 4. an inwardly projecting section of body wall above the first bead, and 5. a second bead member defining an opening in the container, said second bead member having an inwardly indented arcuate portion, a flat flange surface normal to the body wall and projecting radially outward therefrom, and an arcuate portion depending from the outer periphery of the flange surface and terminating inwardly beneath the flange surface; b. said closure device comprising, 2. a membrane-type inner seal, the lower surface of said inner seal adhered along its periphery to the flat surface portion of the second bead member and the upper surface of the inner seal adhered to 2. a reinforcing backing member, and 3. a flexible plastic overcap constructed to provide a snapping-type cap for the container, said overcap having a panel portion and a peripheral depending skirt surrounding the panel portion, said peripheral depending skirt terminating in a shoulder portion which underlies the portion of the second bead member inwardly directed beneath the flange surface thereof and said skirt having an internal peripheral recess proximate the panel within which said inner seal and backing member are press-fit secured, said recess being equal in height and diameter to the arcuate portion of said second bead member, wherein the second bead member projects radially from the upper section of the body wall a distance sufficient to 1. provide clearance between the plastic overcap slirt and the container wall when the plastic overcap is received by the bead member as by snapping the plastic overcap over the bead member, the clearance being of sufficient magnitude to facilitate finger-gripping the skirt to remove the flexible plastic overcap and reinforcing backing member from the container and concomitantly 2. cause the received plastic ovErcap to extend radially a distance substantially equal to the radial dimension of the bottom closed end of the container, and 3. with the inner seal and reinforcing backing members removed from the plastic overcap, to receive the plastic overcap by pressed-fitting in the recess in the peripheral skirt, thereby providing a combination in which the plastic overcap securely recloses the container both with and without the reinforcing backing member and adhered membrane-type inner seal.

2. a metal bottom end panel connected integrally with the body wall,

2. The combination of claim 1 further characterized in that the innerseal membrane is glued to the bead.

2. cause the received plastic ovErcap to extend radially a distance substantially equal to the radial dimension of the bottom closed end of the container, and

2. a reinforcing backing member, and

2. a membrane-type inner seal, the lower surface of said inner seal adhered along its periphery to the flat surface portion of the second bead member and the upper surface of the inner seal adhered to

3. a radially outward projecting first bead formed in the body wall proximate the end of the wall distal the bottom end panel,

3. a flexible plastic overcap constructed to provide a snapping-type cap for the container, said overcap having a panel portion and a peripheral depending skirt surrounding the panel portion, said peripheral depending skirt terminating in a shoulder portion which underlies the portion of the second bead member inwardly directed beneath the flange surface thereof and said skirt having an internal peripheral recess proximate the panel within which said inner seal and backing member are press-fit secured, said recess being equal in height and diameter to the arcuate portion of said second bead member, wherein the second bead member projects radially from the upper section of the body wall a distance sufficient to

3. with the inner seal and reinforcing backing members removed from the plastic overcap, to receive the plastic overcap by pressed-fitting in the recess in the peripheral skirt, thereby providing a combination in which the plastic overcap securely recloses the container both with and without the reinforcing backing member and adhered membrane-type inner seal.

3. The combination of claim 1 further characterized in that the innerseal membrane is heat sealed to the bead.

4. The combination of claim 1 further characterized in that the innerseal membrane is of the pressure-activated adhesive type.

4. an inwardly projecting section of body wall above the first bead, and

5. a second bead member defining an opening in the container, said second bead member having an inwardly indented arcuate portion, a flat flange surface normal to the body wall and projecting radially outward therefrom, and an arcuate portion depending from the outer periphery of the flange surface and terminating inwardly beneath the flange surface; b. said closure device comprising,

5. The combination of claim 1 further characterized in that the innerseal membrane material of construction is selected from the group consisting of glassine, plastic, and foil laminate.

6. The combination of claim 1 further characterized in that the resilient backing material of construction is selected from the group consisting of pulpboard, newsboard and plastic.

7. The combination of claim 1 further characterized in that the plastic cap material of construction is a thermal plastic resin.

8. The combination of claim 1 further characterized in that the plastic cap material of construction is polystyrene.

9. The combination of claim 1 further characterized in that the plastic cap material of construction is a thermal plastic polyolefine.

10. The combination of claim 1 further characterized in that the peripheral skirt of the plastic overcap is formed with an extended section which snugly grips the container wall after the plastic cap has been received by the bead, thereby preventing removal of the plastic cap from the container until the extended section of the skirt is torn away from the container.

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