US3735917A - Egg carton construction - Google Patents

Egg carton construction Download PDF

Info

Publication number
US3735917A
US3735917A US00154373A US3735917DA US3735917A US 3735917 A US3735917 A US 3735917A US 00154373 A US00154373 A US 00154373A US 3735917D A US3735917D A US 3735917DA US 3735917 A US3735917 A US 3735917A
Authority
US
United States
Prior art keywords
flap
cover
front wall
latching
detent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00154373A
Other languages
English (en)
Inventor
R T Warburton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ExxonMobil Oil Corp
Original Assignee
Mobil Oil Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mobil Oil Corp filed Critical Mobil Oil Corp
Application granted granted Critical
Publication of US3735917A publication Critical patent/US3735917A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D85/00—Containers, packaging elements or packages, specially adapted for particular articles or materials
    • B65D85/30—Containers, packaging elements or packages, specially adapted for particular articles or materials for articles particularly sensitive to damage by shock or pressure
    • B65D85/32—Containers, packaging elements or packages, specially adapted for particular articles or materials for articles particularly sensitive to damage by shock or pressure for eggs
    • B65D85/324—Containers with compartments made of pressed material

Definitions

  • a disposable carton formed of low cost material and adapted for the packaging of eggs and the like is formed with coacting elements of a cover and latching flap which, in combination, afford rigidity to those elements, guide the coacting elements on closure and provide for a secure latching susceptible of easy opening.
  • Recesses are provided in cover and latching flap for guidance and rigidity. Latching is accomplished by a recess extending inwardly from the cover front wall to engage the underside of a latching bar of the flap, which is positioned above a substantially rectangular shaped recess in the latching flap.
  • This invention is concerned with disposable cartons for packaging such merchandise as eggs and characteristically comprises a bottom tray portion formed to provide cells for the packaged goods, a top cover portion hinged to the rear of the tray and a latching flap hinged to the front of the tray.
  • the latching flap is adapted to coact with the cover for retention of the closure.
  • the invention concerns the novel structure of the cover and latching flap to assure proper alignment on closing by automatic closure machinery and to afford rigidity to the elements; all in combination with a novel detent, i.e. inwardly projecting recess, and latching bar integrally formed with the cover and flap.
  • egg cartons are today filled and closed on automatic machinery which imposes certain restrictions on acceptable structures.
  • a further restraint on acceptable structures is imposed by the characteristics of the material from which the carton is formed.
  • Most such cartons are prepared on molding machinery from either wood pulp or thermoplastic material and the structure must be such that it can be formed from these inexpensive materials at high speed and readily stripped from the molds.
  • Each of the two types of material (pulp and thermoplastic) and the types of equipment on which these may be formed has its own idiosyncrasies to which the carton structure must accommodate.
  • a typical prior art improvement on the Schilling carton is shown by Reifers US. Pat. No. 2,990,094, provided with a latch having a protrusion on the outward face of the latching flap which enters into and engages the edge of a hole in the face of the cover.
  • An outstanding character of this structure is that the protuberance of the flap extends downwardly when the carton is in extended position, as it exists in the mold, thus, facilitating formation of the protuberance in molding machinery.
  • a sloping face of the cover makes it easy to strip from the mold a cover having a hole therethrough. It is a characteristic feature of the Reifers carton that the front surface of the cover has a high degree of flexibility necessary for proper latching and closure.
  • the improvement on Schillings structure involves a combination of coacting elements in the front surface of the cover and in the latching flap capable of rapid and efficient formation on automatic molding machinery and affording significant advantages in filling, closing, shipping, marketing and household storage.
  • the front of the cover and the latching flap are provided with a number of complementary recesses extending inwardly from the front of the carton and each defined by relatively flat recess surfaces connected to the front primary plane of each element (cover and flap) by webs essentially planar in nature and sloping sharply toward the recessed surface. This combination of webs and planes set at angles to each other provides a beam effect imparting a high degree of rigidity and strength to these elements.
  • the latching flap is characterized by the recess, which is located adjacent to and immediately below the latching bar of the flap, having a relatively large surface area, preferably rectangular in configuration.
  • Such an enlarged recess insures that the relatively smaller inwardly projecting detent member on the front cover wall will seat properly in the latching flap latch recess, even though the carton closing operations may have twisted the latching elements out of proper alignment for positive latching.
  • Such an arrangement substantially eliminates carton latching difficulties encountered as a result of the latching elements being provided in partial recesses but obstructed by latching elements which interfere with these recesses acting with full effectiveness for guidance purposes.
  • the inwardly projecting detent member on the front wall of the carton may assume a variety of configurations.
  • it may be substantially rectangular to conform symmetrically to the rectangular recess which it engages when the carton is in a closed and latched condition.
  • the width dimension of such detent members must be sufficiently smaller than the width dimension of the rectangular locking flap recess to assure ease of entry of the detent and therefore proper locking engagement of the carton sections in the carton closed position.
  • FIGS. 1 and 2 are perspective views of one form of the carton in varying stages of closure;
  • FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;
  • FIG. 4 is a fragmentary view illustrating a form of the invention in which the latching mechanism is entirely shielded in the closed carton;
  • FIG. 5 is a sectional view taken along line 55 of FIG. 4;
  • FIGS. 6 and 7 are perspective views, similar to FIG. 1, showing other specific embodiments of the carton structures of the present invention.
  • FIG. 8 is a fragmentary view of a carton, similar to FIG. 4, showing still another embodiment of the cartons contemplated by the present invention.
  • FIG. 9 is a cross-sectional view of the carton section illustrated in FIG. 8 and taken on line 99 of FIG. 8.
  • the carton is constituted by a bottom tray portion 1, a cover 2, and a latching flap 3.
  • the tray portion is formed to provide a plurality of cells 4 for reception of eggs and the like molded integrally with dividing surfaces and an upper flange 5 which may lie wholly in one plane.
  • the cover 2 is formed integrally with the tray 1 and connected thereto by a portion of reduced thickness 6 constituting a hinge.
  • the latching flap 3 is formed integrally with "the tray 1 and connected thereto by a line of reduced thickness 7 constituting a resilient hinge.
  • the three portions of the carton are in their greatest extended position such that the flange 8 of the cover lies in the same plane as flange 5 of the tray and the latching flap 3 lies extended out to the other side of the carton as formed. This imparts to the hinges 6 and 7 a bias toward extended position.
  • this is constituted by an upper surface 9 which, in the embodiment shown, is essentially planar except for a recess 10, essentially as shown. Molded integrally with the top surface 9 are side walls 11, a back wall 12 and a front wall 13. Formed in the front wall are recesses constituted by depressed surfaces 14 and webs 15 of a structure such as to impart to the front wall a high degree of strength and rigidity capable of supporting burdens of cartons stacked one above another and of maintaining alignment of the front surface for efficient action of the latching mechanism also characteristic of this invention.
  • the latch elements of the cover are constituted by detents 16 formed of recessed surfaces and webs similar to those of the guiding elements, but terminating in a free edge 17.
  • recesses Formed in the latching flap are recesses constituted by recessed surfaces 18 and webs l9 complementary to the recesses in the cover. It will be noted that the cover recesses and those flap recesses employed for guidance of the cover into locked engagement with the flap are wedge shaped and complementary in form. This structure assures that these guidance elements shall become engaged after cover is rotated into closed position and that as the flanges 5 and 8 approach contact, the complementary recesses fit snugly together and assure positive latch engagement.
  • the latching element of the latching flap is constituted by a rectangular recess which is shorter in extent, than those which impart strength and guidance.
  • a recessed surface 20 is connected to the main body of the flap by webs 21.
  • the essentially rectangular shaped recess terminates short of the upper edge of the flap to provide a latching bar 22 above the recess.
  • FIGS. 1 through 3 The embodiment shown in FIGS. 1 through 3 is characterized by a recess in the latching elements of the cover fully extending to the upper surface of the cover. These are readily formed by molding elements similar to those which form the guidance recesses.
  • the detent is readily formed by cutting from such a recess a rectangular portion of the structure indicated generally at 23. This embodiment of the invention is readily formed on automatic thermoforming machinery followed by a cutting operation. I
  • FIGS. 4 and 5 An embodiment quite different in appearance, but identical in coaction of its elements, is illustrated in FIGS. 4 and 5 wherein the recess to provide detent 16 is not continuous to the top of the cover.
  • FIGS. 2 and 3 it will be seen that the only difference is that the latch is covered in the embodiment of FIGS. 4 and 5 when the carton is closed.
  • a carton of this latter type is preferably formed by a thermoforming operation which molds the guidance and rigidity recesses followed by an operation of cutting a slit 24 in the face of the cover and depressing a portion below that slit to form the detent.
  • detent member 16' is substantially rectangular in shape as contrasted to the wedge-shaped detent configuration of the carton illustrated in FIGS. 1 and 2. It will be noted that the rectangular configuration of the detent member 16 conforms substantially to the rectangular recess 20 of the carton locking flap. As hereinbefore disclosed, when the carton is in a closed and locked position, mating rectangular recesses and 16 assist in preventing lateral shifting of the carton cover section and bottom section during the handling of such cartons.
  • the carton illustrated in FIG. 7 is substantially identical to the carton of FIG. 6, however, it will be noted that the recess in the front wall of the carton cover above aperture 23 has a substantially rectangular configuration, i.e., the side walls of the recessare substantially parallel.
  • Such an arrangement allows for individual cartons to be nested, one within the other, during storage or shipment thereof, more readily than the carton illustrated in FIG. 4.
  • the bottom outward portion of the cells 4 be provided with feet 26.
  • a particular material which has been found to be well suited for fabrication of the present carton structures is foamed polystyrene.
  • the closed cell structure of the foamed polystyrene is a material which rapidly, reaches equilibrium with atmospheric moisture and therefore exerts no drying effect.
  • the foam material itself is extremely light weight permitting ease of handling and transport.
  • a preferred material employed in the formation of the carton structures of the present invention is plastic and in particular foam thermoplastic materials and especially polystyrene foam.
  • the polystyrene foam may be' manufactured utilizing any one of the number of conventional extrusion techniques, for example, extrusion of foamable polystyrene beads, i.e., beads which have a blowing agent already incorporated in them prior to delivery to an extrusion apparatus or, for example, by direct injection extrusion techniques wherein a foaming agent is added to a molten mass of polystyrene contained within an extruder prior to extrusion thereof from a die orifice. See. U. S. Pat. No. 3,444,283, Carlson.
  • the polystyrene foam sheet material After the polystyrene foam sheet material has been produced utilizing conventional extrusion techniques as discussed above, it may be molded to form the carton structures of the present invention. In general, it is desirable to preheat the formed polystyrene sheet before it is molded in order to assure that the sheet will be at a sufficiently elevated temperature to permit rapid forming of the desired structure in the mold.
  • the cartons of the present invention may be conveniently formed utilizing a molding operation such as match molding, for example.
  • the process employed for forming the cartons may best be understood by a description of a specific embodiment as illustrated in the following example, how ever, such a description is solely for purposes of illustration and is not to be construed in a limiting sense.
  • the following embodiment sets forth rather specific process and operating conditions employed when preformed polystyrene foam is employed as the starting material for the structure and, of course, such conditions will normally vary when other plastic materials are employed.
  • EXAMPLE l A preformed sheet of polystyrene foam material with an average density of about 7 pounds per cubic ft. and approximately mils thick was fed into a radiant preheat oven and heated to a temperature of approximately 225F. Upon emerging from the preheat oven, the polystyrene sheet was approximately 200 mils thick as a result of the expanding action of the residual blowing agent, in this case pentane, which remains entrapped within the polystyrene cells after it is extruded. The residence time of the polystyrene-in the oven was approximately 5 to 20 seconds and the average line speed was about 15 ft. per minute.
  • the polystyrene foam sheet passes into a forming mold.
  • the thermoforming mold employed is essentially a temperature controlled female mold maintained at about F. and a lower male forming member maintained at a temperature of about 100F. As the match mold is cycled, the upper and lower mold members are brought together forcing the heated polystyrene foam to assume the configuration of the mold members.
  • the shape of the molds and of the freshly molded carton is essentially that shown in FIG. 1 except that rectangular opening 23 has not been cut.
  • the cover and flap in extended position as would appear on rotation of elements in FIG. 1 is as follows: the cover is rotated to the left to a position in which flange 8 lies in the same plane as flange 5 and the flap is rotated to the right until it also lies in that same plane.
  • Rectangular opening 23 is formed by a second operation in which the carton cover 2 is supported against a surface having a suitable die orifice and the openings 23 are cut out by punches.
  • the openings 23 may be formed in the mold by providing reciprocating elements in the female part of the mold which punch out the opening. Similar elements are used to form the embodiment shown in FIGS. 4 and 5. It will be immediately apparent that a female mold of fixed configuration which will form the recessed surfaces and webs of detent 16 would have a portion overlying that part of the front wall of the cover immediately above the detent 16.
  • the freshly formed carton without such detent may be transferred to a second stage at which the slit 24 is cut and a heated element of suitable shape pressed against the carton to depress a portion under the slit, forming the detent 16.
  • a carton adapted for the packaging of eggs and the like having 1. a bottom tray formed to define a plurality of cells for reception of packaged articles and of a depth such that said articles are enclosed thereby for a portion less that their vertical dimension as packaged,
  • a cover resiliently hinged to the rear upper edge of said tray and having side and end walls fixed to each other and to a top for said cover, all of such dimensions that the packaged articles are substantially enclosed when the edges of said tray, said front wall lying primarily in a plane sloping inwardly toward said top, and
  • a latching flap hinged to the front upper edge of said tray by resilient means biasing said flap toward a position outward of vertical from said front edge; said cover and said flap having coacting means associated therewith capable of engagement upon closure of the carton in a manner to maintain such closure;
  • At least one recess in said front wall defined by a wedge portion extending to and tapering outwardly toward the top of said cover and spaced inwardly from the primary plane of said wall, and rigidity-imparting webs connecting said wedge portion with the main body of said front wall lying in said primary plane,
  • At least one recess in said flap said recess having a substantially rectangular configuration, terminated short of the upper edge of said flap by a latching bar extending along said edge and positioned in the primary plane of said flap arranged and adapted for contact with said detent on closure to depress the flap against resilience of its hinge and for engagement of said detent upon completion of closure.
  • a carton according to claim 1 having said detent formed by removal of a section of said wedge portion.
  • a carton according to claim 1 having said front wall of the cover continuous and lying in the primary plane thereof above said detent.
  • a carton according to claim 1 having a plurality of said recesses spaced along the front wall of said cover.
  • a carton according to claim 1 constituted of a foamed thermoplastic resin.
  • a carton according to claim 1 constituted of foamed polystyrene.
  • a carton according to claim 1 having three said recesses spaced along the front wall of said cover.
  • a carton according to claim 4 having said detent spaced between two of said recesses.
  • a carton according to claim 8 having three said recesses and two said detents.
  • a carton according to claim 9 constituted of foamed polystyrene.
  • a carton according to claim 1 wherein said inwardly projecting detent has a substantially rectangular configuration.
  • a carton according to claim 12 wherein said inwardly recessed portion above said detent is substantially rectangular.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Cartons (AREA)
  • Packaging Frangible Articles (AREA)
US00154373A 1971-04-27 1971-06-18 Egg carton construction Expired - Lifetime US3735917A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US13791571A 1971-04-27 1971-04-27

Publications (1)

Publication Number Publication Date
US3735917A true US3735917A (en) 1973-05-29

Family

ID=22479615

Family Applications (1)

Application Number Title Priority Date Filing Date
US00154373A Expired - Lifetime US3735917A (en) 1971-04-27 1971-06-18 Egg carton construction

Country Status (6)

Country Link
US (1) US3735917A (de)
BE (1) BE782754A (de)
DE (1) DE2220274C3 (de)
FR (1) FR2136759A5 (de)
IT (1) IT959650B (de)
NL (1) NL7205616A (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2128962A (en) * 1982-10-22 1984-05-10 Diamond Int Corp Moulded carton locking system
GB2131398A (en) * 1981-09-29 1984-06-20 Diamond Int Corp Moulded egg cartons
US4612153A (en) * 1984-07-12 1986-09-16 Mobil Oil Corporation Process and apparatus for thermoforming a thermoplastic carton having an aperture therein for latching the cover
US4625905A (en) * 1983-04-01 1986-12-02 Mobil Oil Corporation Hinged cover carton
US4742953A (en) * 1983-04-01 1988-05-10 Mobil Oil Corporation Hinged cover carton with inboard locking extensions
US20050145529A1 (en) * 2003-12-31 2005-07-07 Andrews Alan P. Egg carton
US20140042169A1 (en) * 2011-02-22 2014-02-13 Brødrene Hartmann A/S Egg Package
US10549874B2 (en) * 2010-02-24 2020-02-04 Cmd Corporation Pouch machine with sealer

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3207409A (en) * 1962-09-04 1965-09-21 Diamond Int Corp Molded pulp egg carton
US3215326A (en) * 1963-11-20 1965-11-02 Keyes Fibre Co Molded pulp carton latch
US3259294A (en) * 1963-03-12 1966-07-05 Skandinavisk Emballage Aktiese Moulded pulp packing and method for producing same
US3459360A (en) * 1967-03-08 1969-08-05 Keyes Fibre Co Locking means for carton covers
US3465947A (en) * 1967-03-08 1969-09-09 British Petroleum Co Containers

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2600130A (en) * 1945-12-03 1952-06-10 Shellmar Products Corp Egg carton
US2517465A (en) * 1946-05-30 1950-08-01 Shellmar Products Corp Molded pulp carton
US2990094A (en) * 1957-04-19 1961-06-27 Diamond National Corp Molded pulp egg carton
US3215327A (en) * 1965-03-19 1965-11-02 Keyes Fibre Co Locking aperture for molded pulp container
US3539092A (en) * 1969-01-02 1970-11-10 Thermo Trim Inc Egg carton latch
DE6912825U (de) * 1969-03-29 1971-01-14 Silver Plastics Gmbh & Co Kg Eierverpackung.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3207409A (en) * 1962-09-04 1965-09-21 Diamond Int Corp Molded pulp egg carton
US3259294A (en) * 1963-03-12 1966-07-05 Skandinavisk Emballage Aktiese Moulded pulp packing and method for producing same
US3215326A (en) * 1963-11-20 1965-11-02 Keyes Fibre Co Molded pulp carton latch
US3459360A (en) * 1967-03-08 1969-08-05 Keyes Fibre Co Locking means for carton covers
US3465947A (en) * 1967-03-08 1969-09-09 British Petroleum Co Containers

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2131398A (en) * 1981-09-29 1984-06-20 Diamond Int Corp Moulded egg cartons
GB2128962A (en) * 1982-10-22 1984-05-10 Diamond Int Corp Moulded carton locking system
AU576306B2 (en) * 1982-10-22 1988-08-25 Packaging Corporation Of America Molded egg carton
US4625905A (en) * 1983-04-01 1986-12-02 Mobil Oil Corporation Hinged cover carton
US4742953A (en) * 1983-04-01 1988-05-10 Mobil Oil Corporation Hinged cover carton with inboard locking extensions
US4612153A (en) * 1984-07-12 1986-09-16 Mobil Oil Corporation Process and apparatus for thermoforming a thermoplastic carton having an aperture therein for latching the cover
US20050145529A1 (en) * 2003-12-31 2005-07-07 Andrews Alan P. Egg carton
WO2005065215A2 (en) * 2003-12-31 2005-07-21 Pactiv Corporation Egg carton
WO2005065215A3 (en) * 2003-12-31 2006-02-16 Pactiv Corp Egg carton
US7255231B2 (en) 2003-12-31 2007-08-14 Pactiv Corporation Egg carton
US10549874B2 (en) * 2010-02-24 2020-02-04 Cmd Corporation Pouch machine with sealer
US20140042169A1 (en) * 2011-02-22 2014-02-13 Brødrene Hartmann A/S Egg Package
US8991604B2 (en) * 2011-02-22 2015-03-31 Brødrene Hartmann A/S Egg package

Also Published As

Publication number Publication date
DE2220274A1 (de) 1972-11-09
NL7205616A (de) 1972-10-31
DE2220274B2 (de) 1981-02-26
FR2136759A5 (de) 1972-12-22
DE2220274C3 (de) 1981-10-08
BE782754A (fr) 1972-10-27
IT959650B (it) 1973-11-10

Similar Documents

Publication Publication Date Title
US3648916A (en) Carton
US4240575A (en) Egg carton with crush resistant top
US3333726A (en) Hinge for container
US3732999A (en) Bottle with external compartment
US3675808A (en) Knockdown foamed plastic shipping container
US4612153A (en) Process and apparatus for thermoforming a thermoplastic carton having an aperture therein for latching the cover
US3326443A (en) Egg carton
US3954179A (en) Container
US3441071A (en) Plastic container
US3735917A (en) Egg carton construction
US3967993A (en) Protected container and a process for preparing same
US3687350A (en) Egg carton cell structure
US3392902A (en) Carton with cushioning insert of foam plastic material
US3409199A (en) Packaging tray
US3567107A (en) Egg carton
US4625905A (en) Hinged cover carton
US4419068A (en) Molding apparatus having a vented female mold member for forming foamed egg cartons
IE41706L (en) Egg carton
US4872608A (en) 18 Cell egg carton with angled latch flap
US3779370A (en) Egg carton
US3426890A (en) Tap box
US3448775A (en) Hollow container body
US3908891A (en) Divisible thermoplastic egg carton
US3223275A (en) Cigarette box
US3510049A (en) Egg carton