Method of forming a reclosable package

Abstract

 A reclosable food package (1) of deformable, semi-­rigid plastic material with indents, forming a locking means (18, 19), formed into the package container body (3) and closure member (2) simultaneously after filling and sealing to insure that both the body container (3) and closure member (2) snap together to close the package after opening.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[0001] This invention relates generally to food packages. More specifically, this invention relates to food packages having a cover and base defining a cavity for receiving foodstuff and locking means added into the vertical walls of the base and cover to providing snap or interference locking of base and cover in telescopic engagement with each other.

[0002] More specifically, this invention pertains to a food package having a base and a transparent cover. The food package has a sealing means for hermetically sealing the base to the transparent cover and a reclosable means in addition to the sealing means for snap locking the base and the transparent cover in telescoping relationship with each other. More specifically, this invention relates to packages for sliced food arranged in stacks, especially stacks of sliced luncheon meat.

[0003] In one embodiment of this invention, packages are formed from a semi-rigid base and cover, the base and cover mating to form an enclosed product receiving cavity surrounded by a hermetically sealed flange.

DESCRIPTION OF THE PRIOR ART

[0004] Two component packages of this general type are known commercially and are in the patented art. In this connection the packages of the present invention may be viewed as improvements of the sliced food packages described in the Cornish et al. U.S. Patent No. 4,411,122, patented October 25, 1983 and the Seiferth et al. U.S. Patent No. 3,498,018, patented March 3, 1970. Sliced food packages disclosed in U.S. Patent No. 3,595,428 to Mounts et al. patented July 27, 1971 discloses a somewhat raised pedestal on the base but does not provide for telescoping action between pedestal and cover. U.S. Patent No. 3,556,337 to Harmon et al. patented January 19, 1971 discloses packages which contain a locking means designed in the planar flanges and spaced a distance from the cover wall. U.S. Patent No. 4,202,464 Mohs et al. issued May 13, 1980 discloses a locking means contained in a minor portion of the flange. None of these patents provide locking means in the vertical walls of the base and cover, designed to allow the pedestal of the base to telescopically lock into the cover cavity.

[0005] The packages of the present invention may also be viewed as improvements of the sliced food packages described in the Scott U.S. Patent No. 4,498,588, issued February 12, 1985. The Scott, 4,498,588 patent discloses but does not claim the inclusion of ridges and grooves in the packaging chamber for "interlocking engagement". None of the above patents disclose a means for forming interference-locking indents in the walls of the base and cover after the package has been filled with product and assembled and sealed.

[0006] The food package of the present invention thus exhibits certain improvements over the food package disclosed in U.S. Patent No. 3,498,018 to Seiferth et al. or U.S. Patent No. 4,411,122 to Cornish et al. or U.S. Patent No. 4,498,588 to Scott in that the product can be properly pressed and evacuated within the cover by means of pressure on either the cover or pedestal base because of the telescopic movement of the pedestal base into the cover. By then produc­ing a locking means on the vertical walls of the cover and base there is obtained an attractive food product in a container providing reclosable and locking means.

[0007] Many problems exist with the prior art, such as difficulties manufacturing the indents, tabs, grooves, beads or other locking means in the engaging walls of the base and cover due to the close tolerences needed to ensure proper mating of corresponding locking means and proper reclosure and sealing. Additionally, it is quite difficult to mold indents or locking means in the base and cover and then be able to strip them from the mold.

SUMMARY OF THE INVENTION

[0008] In general, it is an object of the present invention to provide a method for the manufacture of a package that comprises a cup shaped container body and a closure member telescopically engaging one another to seal in a product. After the assembly of the container body, a predetermined amount of product and the closure member a snap or interference locking means can be formed by the use of male and female tooling dies in the area of the body and closure member that are telescopically engaged.

[0009] These and still further objectives are addressed hereinafter.

[0010] In general, the foregoing objectives are achieved by filling the container body with a predetermined amount of product then sealing the container body and product with a closure member as described in U.S. Patent No. 3,498,018 issued to Seiferth et al. and incorporated herein by reference. After the package is filled and sealed snap-locking means are formed in the package so that upon opening and reclosing of the package by the consumer the container body and closure member snap-lock together.

[0011] For a more complete understanding of the nature and scope of the invention, reference may be had to the following detailed description the preferred embodiment taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 

Figure 1 is a perspective view of an embodiment of a sliced food package;

Figure 2 is a vertical sectional view of an embodiment broken away in the center and differing from that of Figure 1;

Figure 3 is a side view of a third differing embodiment of a container body having conduit means;

Figure 4 is a view of the base closure member;

[0013] In Figures 1 and 2, a sliced luncheon meat package (indicated generally as 1) is formed by a semi-rigid base closure member 2 and a semi-rigid container body 3. Slice luncheon meat is contained between the container body 3 and the base closure member 2 and may constitute any of the usual sliced sausage or luncheon meat such as bologna, salami, New England Brand Sausage, etc. and non-meat products such as sliced cheese. While particularly suitable for sliced food products the package of the invention can also be used for non-sliced compressible items. The base closure member 2 and container member 3 may be formed in any known manner from semi-rigid material such as aluminum laminated or impregnated paper which is moisture resistant and gas impermeable, or plastics. Examples of suitable plastic materials are polyvinylchloride, cellulose acetate, nylon, polycarbonate, high impact polystyrene, high impact polypropylene, high impact polyethylene, polyester, acrylonitrile copolymers, extruded plastics, etc. These plastic materials may be coated with saran or other coating if desired. Copolymers of these various plastics may be used in order to obtain desired properties.

[0014] The semi-rigid base closure member 2 includes a raised pedestal generally indicated in Figure 2 at 5. This raised pedestal allows the food product to be pressed by force applied to either the base member 7 and/or the container 10 of Figure 2 so that product is forced between the base 7 and cover 11 of Figure 2. The telescoping action of base and cover compress the meat product between them such that voids are removed while at the same time the vacuum applied to the interior generally shown as 15 of Figure 2 draws together the container body and base closure member and further compresses the meat products so that the contents or food product touches all inner surfaces that contact or could contact the food product.

[0015] Deforming means generally shown at 16 and 21 of Figure 2 allows the cover or base or both to deform under the pressure and vacuum applied to the product thus insuring that the entire contents of the package closely touch the inner surfaces of the package and provide a pleasing appearance free of voids and open spaces which cause a poor quality looking product on sealing the flange areas 22.

[0016] Deforming means generally shown at 16 allow the semi-rigid plastic material to flex and deform sufficient to provide a tight fit of product against the inner face of the cover upon application of pressure and vacuum and final sealing of product.

[0017] The raised pedestal and side wall of the container body are shown to have interference closure means, generally indicated as 18 and 19 in Figures 2, 3 and 4 formed in them. The locking means is formed into the raised pedestal and side wall after filling with product, assemblage and sealing. The locking means consists of corresponding indents formed simultaneously in the container body and the raised pedestal portion of the closure member after sealing and by mechanical means such as, for example, tooling dies.

[0018] Figures 3 and 4 illustrate in more detail the indents 18 and 19 of the specific locking means of this invention on both a container body and a closure member. Figure 3 illustrates an embodiment of a container body of the package showing the indents 18 formed after sealing and also having a slightly narrower diameter (shown at 30) above the point were the pedestal shown in Figure 4 will stop. The container body continues above this narrowed portion at 30 which provides for full advancement of the pedestal into the container body 31 up to a position below the narrowed section at 30. Also shown in this embodiment are vertical passageways or conduits 32 designed to provide rigidity to the semi-rigid container body and also to provide a passageway for gases to be drawn off during evacuation thus ensuring a good contact of the food with the inner surfaces of the package. While these conduits are shown to cover the entire length of the vertical portion of the container body they need not do so if able to carry away sufficient gas to produce a desirable looking product. While the indents are shown to protrude outward on the wall of the container body and closure member pedestal they may be formed in a reverse manner and indent inward.

[0019] While the embodiments discussed and illustrated provide for sealing under pressure and vacuum of the base and cover, the packages may be filled with an inert gas if desired. Once vacuum is pulled the gas would be introduced through the same vertical passage­ways 32 in Figure 3 prior to heat or adhesive sealing. Gas packaging provides for a loose fit of the meat against each other and the package. The vertical wall locking feature of this invention is applicable to all gas packaging for telescoping cover and base packages.

[0020] This invention can be embodied in various forms and therefore is to be construed and limited only by the scope of the following claims.

Claims

1. A method of forming a package which has a preformed cup-­shaped container body of deformable semi-rigid plastic material in combination with a closure member of deformable material, characterised by using a container and closure member having means to permit variation of internal package volume in response to external mechanical pressure, said container body having margin portions adapted for sealing, said closure member having portions overlying the mouth of said container body and being adapted for sealing said cup-shaped body in telescopic engagement therewith, said method comprising placing a predetermined quantity of product in said container, placing said closure member on said body member, applying sufficient mechanical pressure to said closure member to force the same into intimate engagement with said product and said container body so as to form therewith a rigid unitary package, sealing said margin portions and thereafter forming an interference closure means.

2. A method according to claim 1, wherein said closure means is provided by applying sufficient mechanical pressure to permanently deform said closure member and said container body at a predetermined section where said container body and said closure member are telescopically engaged, said permanent deformed section being sufficient in depth, width and length to function as a friction or interference closure means.

3. A method of forming a package as claimed in either of claims 1 and 2 wherein said interference closure means is mechanically formed by tooling dies.

4. A method of forming a package as claimed in any one of claims 1 to 3 wherein said cup-shaped container body is rectangular.

5. A method of forming a package as claimed in any of claims 1 to 4 wherein said cup-shaped container body contains conduit means.

Drawing