US3441196A - Egg carton - Google Patents

Description

F. L.. BURKETT EGG CARTON April 29, 1969 Sheet of3 Filed Feb.

INVENTOR. Franc/l5 A Burkff ATTORNEYS April 29, 1969 F. L. BURKETT 3,441,196

- EGG CARTON Filed Feb. 5, 1967 Sheet 2 of 3 Egg; 3 x3. 7-

INVENTOR. France L. Burkeff EGG CARTON Sheet Filed Feb. 5, 1967 INVENTOR. Franc/Is- A Burke/i HTTOR/VEYS United States Patent 3,441,196 EGG CARTON Francis L. Burkett, Breckenridge, Mich., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware Filed Feb. 3, 1967, Ser. No. 613,775 Int. Cl. B65d /66, 1/00, 65/16 US. Cl. 22944 8 Claims ABSTRACT OF THE DISCLOSURE A unitary see-through egg carton having a tray with egg cells and a see-through cover hingedly connected to the tray, the cover being secured closed with the tray by either an acute angle latch or a snap-over, flip-open latch This invention relates generally to a unitary, seethrough egg carton preferably formed from plastic foam and plastic film materials. More particularly, this invention relates to a unitary see-through egg carton having a shock absorbing plastic foam tray and a hingedly connected transparent or translucent plastic film or sheet cover. In various embodiments this invention further comprehends an egg carton having especially advantageous and highly secure latch constructions, the latch, plastic foam base, and plastic film cover being in a mutually cooperating relationship to provide an especially attractive, practical and protective egg carton.

Prior to the present invention there has not been a fully satisfactory egg carton. None have offered the convenience and practical advantages of unitary construction and provided adequate structural and shock protection properties, while also providing free viewing of the contained eggs to better facilitate their quick and easy inspection.

Accordingly, it is an object of the present invention to provide a novel and improved unitary, preferably all plastic, egg carton, the construction of which provides adequate structural and shock protection properties, while still allowing for quick and easy inspection of its contents.

Another object of the present invention is to provide a novel and improved unitary, preferably all plastic, egg carton having, in addition to the above advantages, an especially secure latch mechanism between its tray and cover.

Briefly then, the present invention contemplates a preferably all plastic egg carton of advantageous unitary construction having adequate shock resistant and stacking properties while still allowing for free viewing of the eggs contained within. Such an egg carton comprises a shock resistant plastic foam tray and a hingedly connected transparent or translucent plastic film or sheet cover. The tray would customarily contain a dozen egg cells, which can be arranged in two parallel rows defining five pillar structures at the internal cell junctions. The pillar structures, if desired, can be extended upwardly beyond the upper horizontal plane of the egg cells to a position supporting the top horizontal portion of the hingedly connected cover thereby greatly improving the stacking properties of the carton. Further, the more vertical sidewalls of the cover can be recessed at strategic points to a position juxtapositioned with the contained eggs so as to both structurally reinforce the cover and also stabilize or prevent movement of the eggs in their respective cells, The invention further comprises a novel acute angle latch construction to lock the carton shut in an especially secure fashion. In another embodiment, the invention includes a different latch construction whereby the cover is secured by a simple snap-over, flip- Patented Apr. 29, 1969 open latch to provide an especially easy opening and reclosable egg carton.

Yet additional objects and advantages of the present invention, and its numerous cognate benefits and features are even more apparent and manifest in and by the ensuing description taken in conjunction with the accompanying drawing in which, wheresoever possible, like reference characters designate corresponding materials and parts throughout the several views thereof in which:

FIGURE 1 is a plan view of an open egg carton constructed according to the principles of the present invention;

FIGURE 2 is a plan view thereof, when closed;

FIGURE 3 is a front elevation view thereof, when closed;

FIGURE 4 is a cross-sectional view thereof taken along reference line 44 of FIGURE. 2;

FIGURE 5 is a fragmentary front elevation view of a modified form of an egg carton, when closed, including a modified latch construction;

FIGURE 6 is a cross-sectional view thereof taken along reference line 66 of FIGURE 5;

FIGURE 7 is a fragmentary plan view of the modified egg carton; and

FIGURE 8 is a plan view thereof, when opened.

Referring now more particularly to FIGURES 1 to 4, there is shown a thermoplastic egg carton 10 which basically comprises a base or tray portion 12 containing a dozen egg cells 14 and pillars 15 located centrally of each quadrant of egg cells 14. Carton 10 further includes a back hinge flap 16 extending from back portion 13 of tray 12 along score or crease line 18, and a hingedly connected cover or lid 20 longitudinally adhered along its back portion 27 to back hinge flap 16 (as shown in FIG- URE 4). A front flap 22 having a flat outer surface 31 extends from the tray 12 along score or crease line 24. Upon the closing of carton 10 the lid 20 substantially mates with the peripheral extent of rim 52 of tray 12.

Tray 12, back hinge flap 16, and front flap 22 can be formed from a one-piece plastic foam sheet material, such as expanded polystyrene, generally by plug assist and vacuum drawing and then, if desired, scored or creased along lines 18 and 24. Egg cells 14 are preferably formed, when tray 12 is formed from extruded plastic foam sheet, by a matching die technique with the plug grooved and fitted for vacuum operation so that a plurality of side ribs or cushions 26 and a puffed bottom cushion pad 28 are integrally formed, by opposed vacuum drawing, on the inside of the cell walls of each cell 14. Such cushions 26 and pads 28 can add substantially to the shock absorbing capacity of the egg carton.

Lid 20 comprises a flat top portion 53 and a sidewall 36 integral with and extending downwardly and outwardly from the top portion 53. Sidewall 36 has a front wall 34 and back wall 35. The lid 20 is preferably formed of a clear or transparent or translucent polystyrene or other comparable plastic film or sheet material capable of maintaining its own weight and shape generally without additional support. It can be pressure formed to achieve the shape illustrated, which forming technique is well known in the art. Lid 20 can be adhered to hinge 16 of carton 10 by adhesives, heat sealing where possible, e.g., when the plastic materials of the lid and tray are compatible, or by any other well known and suitable technique. This hinged construction as shown above is particularly advantageous, especially when lid 20 is formed from the preferred unexpanded polystyrene plastics. Polystyrene film or sheet materials, of generally self-supporting gauges for application such as those concerned here, were found generally unsatisfactory where a portion thereof took a hinging action as they had a tendency to crack or break when bent too severely. Conversely, polystyrene foam, the preferred tray and hinge material of this invention, Was found to be relatively easily scorable or creasable and when so scored or creased was found to possess both excellent bending and hinging properties. Thus, it was discovered that by placing the hinging and bending stresses involved in the opening and closing of carton in the plastic foam, through its back hinging flap 16, a superior unitary egg carton was provided. It is conceivable, however, that if lid is formed of more pliable materials, such as polyethylene or plasticized polystyrene, it could adequately provide the necessary hinging properties.

Latch projections protrude outwardly from flap 22 at an angle a which is acute to the fiat outer surface 31 of flap 22 (shown most clearly in FIGURE 4). Since the front wall 34 of sidewall 36 of lid 20 is substantially parallel with surface 31 when carton 10 is in its closed position, projections 30 will also be at an acute angle with the front wall 34. In this particular illustration angle a is about 71, it being understood that this angle can vary several degrees in either direction and still accomplish the object of the present invention.

Adapted to mate with each projection 30 is an aperture 32 along the front wall 34 of lid 20. Thus, when a projection 30 extends through aperture 32 it is securely locked in position. That is, the undercut provided by the angle a on the underside of latch projection 30 insures a more positive sealing action with the aperture 32.

The slope of front wall 34 and back wall 35 of sidewall 36, angle b shown in FIGURE 4, can be adjusted, if desired, to cause front flap 22 and back hinge 16 to press against or to be juxtapositioned with the upper walls of the contained eggs (not shown), thus better preventing movement of the eggs within the carton and consequently better insuring against egg breakage.

Modified carton 40, illustrated in FIGURES 5-8, is formed in a similar manner and of similar materials to carton 10. Thus, carton comprises a plastic foam base or tray portion 42, containing a dozen egg cells 14, a back hinge flap 17 extending from base 42 along score or crease line 18, and a hingedly connected transparent or translucent plastic film cover or lid longitudinally adhered to back hinge flap 17, as previously described with regard to carton 10.

Base 42 includes pillars 15, located centrally of each quadrant of egg cells 14, which extend above horizontal rim 52 of the tray 42 to a height which will support the inside of fiat top portion 53 of lid 50. By having such a high pillar structure the strength of the lid 50 is greatly increased, particularly for stacking purposes.

Integral with sidewall 54 of lid 50 are reinforcing recessed portions or indents 56 (most clearly illustrated in FIGURE 8) which can, if desired, be extended inwardly a sufiicient distance to be juxtapositioned with the walls of the contained eggs (not shown) to better prevent movement of the eggs within the carton.

Horizontally disposed shoulders 58 extend outwardly from bottom or lower end portion 55 of indents 56 to substantially mate, when the carton is closed, with similarly disposed shoulders of base 42, the mutual support of shoulders 58 and 60 further strengthening the stacking ability of carton 40.

Latch assembly 64 (most clearly illustrated in FIG- URES 5 and 6) comprises a latch detent 62, preferably extending downwardly from a shoulder 58 of lid 50, and a cutback portion 65 disposed opposite latch detent 62 on rim 52 of tray 42. Shoulder 58 is, for this application, preferably cut back to mate with the cutback portion 65 of rim 52 as shown in FIGURES 6 and 8. It should be noted, however, that, if desired, latch detent 62 can extend directly from a bottom end portion 55 of an indent 56 (not shown).

Latch detent 62 comprises a detent or curl 66 having an inside diameter preferably equal to or slightly in excess of the vertical thickness of rim 52 of tray 42, and

a latch or handle 61 integral with the curl 66 and extending downwardly and outwardly therefrom. Carton 40 is easily closed by snapping curl 66 over the cutback por tion 65 of rim 52, curl 66 being formed sufliciently inwardly to insure a relatively tight pressure fit between itself and the cutback portion 65 of rim 52. Conversely, the carton can be flipped open by a slight upward pressure on the handle 61. It should be noted also that the special recessed design of latch assembly 64 better protects the carton against possible accidental openings.

While the above egg cartons have been described in particularity with reference to a tray comprised of polystyrene foam and a cover comprised of polystyrene film or sheet, other plastics in their respective foam, film or sheet form with similarly satisfactory properties, such as polyethylene, polypropylene, and polyvinyl chloride foam, film or sheet may be readily substituted therefor.

Also, it is conceivable that the tray portion of the carton could'be made of other suitable materials such as molded pulp, paperboard and film or sheet plastics.

While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. Such changes can be made in other structures and materials which serve to achieve the principles of this invention.

Accordingly what is claimed as new is:

1. A unitary see-through egg carton comprising a tray having a plurality of egg cells integrally formed therein, said tray comprising expanded plastic material and including a back flap, said back flap hingedly connected to a back part of said tray, a lid covering said tray and thereby closing said carton, a back portion of said lid fixedly attached to said back flap, said lid comprised of a substantially transparent plastic material to enable visual inspection of eggs contained within said carton without opening the carton.

2. The carton of claim 1 wherein the tray material comprises polystyrene foam and wherein the lid material comprises a non-expanded polystyrene.

3. The carton of claim 1 wherein the lid includes a generally inwardly and upwardly sloped front sidewall and a generally inwardly and upwardly sloped back sidewall, and said tray includes a hingedly connected front flap, said front flap and said back flap extending from said tray inwardly and upwardly behind and generally parallel to said front and back sidewalls, respectively, when the carton is in a closed position, thereby extending the protective cushion-like qualities of said tray material in the form of said front and back flaps to portions of said lid.

4. An egg carton comprising a tray, a plurality of egg cells integrally formed in said tray, a lid hingedly connected to and covering said tray and thereby closing said carton, said lid including a generally inwardly and upwardly sloped sidewall, at least one indent integrally formed in said sidewall at a location remote from said hinged connection between said lid and tray, a generally horizontally disposed shoulder integrally formed with and extending outwardly of said indent adjacent the lower end thereof and wherein said tray includes at least one generally horizontally disposed shoulder located so as to mate with said shoulder of said lid when the carton is closed.

5. The carton of claim 4 wherein eggs are contained within said carton, said indent being in a generally juxtaposed relationship with a wall portion of at least one of said eggs when the carton is closed.

6. The carton of claim 4 wherein said carton includes at least one latch assembly, said latch assembly comprising a detent means resiliently attached to and extending generally downwardly from said shoulder of said lid, said detent means adapted to catch on and resiliently pressure lock into a portion of said tray to fasten to- 5 gether thereat the tray and lid thereby securely locking said carton closed.

7. The carton of claim 4 wherein said carton includes at least one latch assembly, said latch assembly comprising a detent means extending generally downwardly from adjacent the lower end of said indent, a cut back portion extending inwardly of said shoulder of said tray and disposed opposite said detent means, a handle integral with and extending outwardly from said detent means, said detent means adapted to resiliently catch on and locked into said cut-back portion, thereby, securely locking said carton closed.

8. The carton of claim 4 wherein said lid comprises a substantially transparent thermoplastic material and wherein said tray comprises expanded plastic material, said tray including a back flap, said back flap hingedly connected to a back part of said tray, a back portion of said lid being fixedly attached to said back flap.

References Cited UNITED STATES PATENTS 3,193,177 7/1965 Crabtree 229-44 3,285,491 ll/ 1966 Bessett 2292.5 3,298,594 1/ 1967 Makowski et al. 2292.5 X 3,307,765 3/1967 Trimble 2292.5 3,351,270 11/1967 Hohnjec 2292.5 X 3,352,477 11/1967 Eisenbcrg 2292.5 X

DAVID M. BOCKENEK, Primary Examiner.

US. Cl. X.R.

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