Carton with easy opening reclosure

Abstract

A carton end closure comprises major flaps and minor flaps hingedly connected to walls of the carton. The outer major flap contains a first pair of diagonally extending lines of weakness for partially opening the carton and a second pair of diagonally extending lines of weakness which are utilized to complete the opening thereof.

Description

BACKGROUND OF THE INVENTION

Efficient and expeditious opening of sealed paperboard cartons has long been a problem in the packaging industry. One method for opening such cartons is to provide a removable tear strip which may be ripped away. A second method is to provide lines of weakness in one of the carton end closures to facilitate opening, as exemplified in U.S. Pat. Nos. 1,985,590, 2,151,202 3,366,311 and 3,438,566. The recently developed usage of very strong adhesives, for example hot melt adhesives or polyethylene coatings, has accentuated the problem. The bond formed by these adhesives is stronger than the paperboard itself and use of ordinary opening features is unsatisfactory, particularly when a tight, vermin-proof seal may be required as in the packaging of raisins, prunes and the like.

SUMMARY OF THE INVENTION

It is an object of the invention to solve the above briefly noted problems by providing an opening device in the closure flaps of a tightly sealed carton whereby the carton may be opened easily and expeditiously.

In the preferred embodiment, the carton comprises front, back and side walls and a manufacturer's glue lap hingedly connected to one of said walls so that the carton may be formed into a tubular structure. Any suitable end flap configuration may be utilized for the bottom closure of the carton. The top end closure comprises minor flaps hinged to each of the side walls, an inner major flap hinged to the front wall and an outer major flap hinged to the back wall. The configuration of the inner major flap and the minor flaps is such that when these flaps are folded inwardly and the outer major flap is then folded down on top of them to form the closure the inner surface of the outer major flap contacts and is sealed to the inner major flap adjacent the front edge of the carton and to the minor flaps adjacent the sides of the carton.

A tab is formed near the center of the front edge of the outer flap and a pair of lines of weakness lead from the tab diagonally backwardly and outwardly toward the rear corners of said flap. When the tab is grasped and pulled upwardly, said flap tears along the lines of weakness releasing the center section thereof from the inner flaps. A second pair of lines of weakness lead from points intermediate the ends of said first pair diagonally forwardly and outwardly toward the front corners of the outer major flap. After completion of the aforementioned partial opening of the closure, the inner major flap may be grasped and pulled upwardly, tearing the remainder of the outer major flap along the second pair of lines of weakness to complete the opening. Means may be provided in the inner major flap to cooperate with the tab to form a reclosure feature.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects of the invention will become apparent from the following description and accompanying drawings wherein

FIG. 1 is a plan view of the outer surface of a paperboard blank adapted to be erected into a carton embodying the invention;

FIG. 2 is a perspective view, in part, of the erected carton with the top closure partially formed;

FIG. 3 is a similar view of the completed carton;

FIG. 4 is a similar view showing the carton after the first step in opening the carton has been completed;

FIG. 5 is a similar view showing the carton completely opened, and

FIG. 6 is a similar view showing the reclosure feature in operation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The blank of FIG. 1 comprises side wall 11, back wall 12, side wall 13, front wall 14 and manufacturers glue lap 15 connected consecutively along scorelines 16, 17, 18 and 19. Bottom closure flaps 21, 22, 23, and 24 are hinged respectively to said walls along scoreline 20. The top closure flaps are hingedly connected to the walls along scoreline 25, which is parallel to scoreline 20, with minor flaps 26 and 28 hinged respectively to side walls 11 and 13, outer major flap 27 hinged to back wall 12 and inner major flap 29 hinged to front wall 14.

The side edges of minor flaps 26 and 28 remote from outer major flap 27 are partially cut away to form inwardly extending diagonal side edges 31 and 32 and vertically extending side edges 33 and 34 respectively. In a similar manner, the side edges of inner major flap 29 are cut away to form diagonal inwardly extending edges 36, 36 and vertically extending edges 37, 37.

A cutout area 38 is formed in the medial area of the free edge of inner major flap 29 remote from scoreline 25. A first cut line 39 extending through inner major flap 29, is formed parallel to scoreline 25, medially with respect to the side edges of said flap. Cut line 39 is spaced from scoreline 25 and is of a length suitable to receive a closure tab on outer major flap 27, to be described hereinafter. Second cut line 41 is formed in scoreline 25 medially of inner major flap 29 with respect to its side edges, and preferably slightly shorter than cut line 39. In contrast to cut line 39 which extends entirely through the flap, cut line 41 extends only partially through the paperboard forming that flap. A pair of third cut lines 42, 42, also extending only partially through the paperboard forming inner major flap 29 extend inwardly of the flap from the end edges of cut line 41 to junctures with the aforementioned cut line 39.

A closure tab 43 is formed in outer major flap 27 medially of its edge which is remote from and parallel to scoreline 25. Closure tab 43 is formed by two cuts, 44, 44 extending from the aforementioned edge of outer closure flap 27 inwardly to scoreline 45 which is parallel to said edge and joins the inner edges of said cuts 44, 44. In the final sealed carton the area of closure tab 43 corresponds to the area of inner major flap 29 inside cut lines 39, 42, 41 and 42 and is sealed thereto. A first pair of lines of weakness 46, 46 in outer major flap 27 extend from the ends of scoreline 45 diagonally outwardly and rearwardly of the flap to the points where the side edges of said flap meet scoreline 25, that is, at the junctures of said scoreline 25 with scorelines 16 and 17 respectively. A second pair of lines of weakness 47, 47, extend from the medial area of said first pair of lines of weakness 46, 46 diagonally forwardly and outwardly to the ends of the free edge of outer major flap 27 which is remote from scoreline 25.

Lines of weakness 46, 46, are shown as consisting of a series of J-cuts and lines of weakness 47, 47, are shown as a series of straight line cuts in the drawings. It should be understood that these respective types of cuts are not critical and that any type of lines of weakness which will permit the type of tearing required is suitable.

To utilize the carton the blank may be folded suitably along scorelines 18 and 16 and manufacturer's lap 15 then is sealed to the inner surface of side wall 11 to form a tubular structure. The tubular structure may then be squared up, the bottom closure flaps suitably folded up and sealed and the contents inserted.

Referring now to FIG. 2 the carton is shown set up in tubular form with the bottom closure sealed and ready for sealing of the top closure. In this configuration, minor flaps 26, 28 have first been folded inwardly and then inner major flap 29 has then been folded inwardly to overlie said minor flaps. It should be understood that the closure will perform equally well if the inner major flap is folded first. As shown in FIG. 2, the aforementioned cutaway areas at the sides of inner major flap 29 expose areas of minor flaps 26 and 28 adjacent their scorelines to contact with outer major flap 27 during sealing. Further, diagonal side edges 31, 32 of minor flaps 26 and 28 substantially coincide with diagonal side edges of inner major flap 29 so that there is substantially no overlap along these contacting areas. This results in what is essentially a single layer of paperboard at this juncture which assists in obtaining a tight seal.

To complete the closure, outer major flap 27 is folded flat against the inner flaps and sealed thereto. Preferably, this seal is effected substantially only in areas adjacent the free edges of outer major flap 27, that is, the areas in FIG. 2 where said outer major flap contacts minor flaps 26 and 28, and in an area of inner major flap 29 adjacent scoreline 25 having a width substantially equal to the distance between scoreline 25 and cut line 39.

Any number of methods may be utilized to effect this selective sealing. Conventional adhesives or hot melt may be selectively pattern applied in the requisite areas. If the blank is coated with a heat activatable adhesive, the areas not to be sealed may be coated with an ink or other substance which inhibits sealing. Alternatively, sealing may be effected by a properly shaped heated bar which contacts only that portion of outer major flap 27 which overlies the area to be sealed, or hot air may be directed only on the requisite area for selective activation of the adhesive.

The closed and sealed carton is shown in FIG. 3. To open the carton, tab 43 is grasped and pulled upwardly. The free edge of tab 43 may be formed to extend slightly beyond the corresponding edge of outer major flap 27, if desired, to facilitate such grasping. Upon pulling upwardly of tab 43, the area of inner major flap 29 between cut lines 39, 42, 41 and 42, which is sealed to said tab, will delaminate from said inner major flap and thus release the tab.

Upon further exertion of an upward pull on tab 43, outer major flap 27 will tear along lines of weakness 46, 46, permitting the central portion of said flap to be pulled into an upright position perpendicular to the original closure. It should be noted that due to the selective sealing hereinbefore described, this portion of outer major flap 27 between lines of weakness 46, 46, is substantially not adhered to the underlying flaps, so that there is little or no resistance to lifting of this portion.

At this point, after partially opening the closure, the carton is in the configuration shown in FIG. 4. The central portion of outer major flap 27 between lines of weakness 46, 46, extends upwardly perpendicular to the original closure and the remaining portions thereof lying outside said lines of weakness remain sealed to minor flaps 26 and 28 and inner major flap 27. In order to complete the opening one need only insert a finger in cut away portion of inner major flap 29 and pull upwardly. Exertion of an upward force on this flap causes those portions of outer major flap 27 which are still sealed to the underlying flaps to tear along weakened lines 47, 47, permitting the inner major flap to be pulled upwardly and open. At this point one need only fold the inner minor flaps outwardly to finish opening of the carton to the configuration of FIG. 5.

It should be noted that in the completed closure, lines of weakness 47, 47 substantially overlie the junctures formed by diagonal edges 31 and 32 of minor flaps 26 and 28 with diagonal edges 36, 36 of inner major flap 29. Thus when tearing takes place along lines of weakness 47, 47, the remaining portions of outer major flap 27 which remain sealed are separately sealed to minor flap 26, minor flap 28 and inner major flap 29, and are all separated from each other so as not to inhibit opening of all flaps.

If it is desired to reclose the carton after partial removal of the contents, the inner flaps may be folded into closed position, tab 43 may be bent inwardly along scoreline 45 and the upright portion of outer major flap 27 to which the tab is attached may be folded to the closed position, with the tab inserted in cut line 39 to lock the reclosure in place.

As can be seen from the foregoing, an efficient and easily operated opening feature is provided for a tightly sealed carton. Further, a reclosure feature may be incorporated therein.

Claims

What is claimed is:

1. A carton structure having an easy opening feature, said carton structure comprising side walls, a front wall, a back wall, a bottom closure and a top closure, said top closure comprising

a. minor flaps hinged to said side walls,

b. an inner major flap hinged to said front wall,

c. an outer major flap hinged to said back wall, said outer major flap folded over and sealed to said other flaps only in areas closely adjacent its side edges and a front edge thereof to form said top closure,

d. a tab formed in said outer major flap medially of the front edge thereof,

e. a first pair of lines of weakness extending diagonally outwardly and backwardly from said tab toward the corners of said outer major flap remote from said front edge,

f. a second pair of lines of weakness extending from medial portions of said first pair of lines of weakness diagonally outwardly and forwardly towards the corners of said outer major flap adjacent said front edge, and

g. cutaway portions at side edges of at least one of (1) said inner major flap and (2) both of said minor flaps, so arranged that said outer major flap is sealed only to said inner major flap in areas adjacent its front edge and only to said minor flaps in areas adjacent its side edges, whereby said closure may be opened by first grasping said tab and pulling upwardly to split said outer major flap along said first pair of lines of weakness and then grasping said inner major flap and pulling upwardly to split the remaining sealed portions of said outer major flap along said second pair of lines of weakness.

2. The carton of claim 1 further comprising releasable means securing said tab to said inner major flap.

3. The carton of claim 2 wherein said releasable means comprises cut lines in said inner major flap extending only partially therethrough.

4. The carton of claim 1 further comprising reclosure means formed in said inner major flap to receive said tab and reclose said carton.

5. The carton of claim 1 further comprising means in said inner major flap for grasping and pulling said flap upwardly.

6. The carton of claim 1 wherein said cutaway portions are only at the side edges of said inner major flap whereby, when said minor flaps are folded inwardly first to form said top closure, portions of said minor flaps are exposed to contact with said outer major flap.

7. The carton of claim 1 wherein said cutaway portions are only at the edges of said minor flaps proximate to said inner major flap.

8. A carton blank comprising

a. a first side wall, a back wall, a second side wall, a front wall and a manufacturer's glue lap serially connected to each other along first parallel scorelines,

b. bottom closure flaps connected to said walls along a second scoreline, and

c. top closure flaps connected to said walls along a third scoreline, and including

d. minor flaps connected to said side walls, an inner major flap connected to said front wall and an outer major flap connected to said back wall,

e. cut means forming a tab at the medial portion of a free edge of said outer major flap remote from said third scoreline,

f. a first pair of lines of weakness in said outer major flap extending diagonally toward the corners of said outer major flap proximate to said third scoreline, and

g. a second pair of lines of weakness in said outer major flap extending from medial portions of said first pair of lines of weakness diagonally toward the corners of said flap proximate said free edge thereof, and

h. cutaway portions at side edges of at least one of (1) said inner major flap and both said minor flaps so arranged that when said outer major flap is folded over on top of said other flaps to form a top closure it contacts only said minor flaps along its side edges and only said inner major flap along its front edge.

9. The carton blank of claim 8 further comprising cut means in said inner major flap adapted to receive said tab and thereby to reclose a carton formed from said blank.