Cartons and blanks for forming cartons

Abstract

A carton has side walls provided with opposed end flaps which form the top and bottom of the carton, a pair of opposed end flaps one end of the carton being disposed in face-to-face relation in the closed condition of the carton. The upper of said pair of end flaps is formed with two lines of weakness so that, to open the carton, the user can effect separation along the two lines of weakness. The lines of weakness in the upper of said pair of end flaps each extend from a corner of the side wall associated with said end flaps at an inclination of, for example, 45.degree. to the line of juncture between the end flap and the side wall.

Description

This invention relates to cartons and to blanks for forming cartons. The present invention is of application both to cartons provided with internal preformed lining sleeves and to cartons not provided with such sleeves.

The present invention is concerned with that kind of carton which includes side walls provided with opposed end flaps which provide the top and bottom of the carton and in which a pair of opposed end flaps at one end of the carton are disposed in face-to-face relation in the closed condition of the carton and the upper of said pair of end flaps is formed with a pair of lines of weakness whereby, to open the carton, a user may effect a separation operation along said lines of weakness, such separation operation providing a tab for engagement in a slot in the lower of said pair of end flaps for effecting reclosing of the carton.

Such cartons are hereinafter referred to for convenience as cartons of the kind specified. Blanks provided with lines of weakness, fold lines and a slot and whose configurations are such that they can be assembled to form cartons of the kind specified are hereinafter referred to for convenience as carton-forming blanks of the kind specified.

The objects of the present invention include the provision of an improved carton of the kind specified and an improved carton-forming blank of the kind specified wherein said pair of lines of weakness are so disposed as to facilitate gluing of the blank.

According to a first aspect of the invention there is provided a carton of the kind specified in which the pair of lines of weakness in the upper of said pair of end flaps each extend from a corner of the side wall associated with said end flap at an inclination to the line of juncture between the end flap and the side wall.

Each of said lines of weakness may extend from the respective corner to a free edge of said end flap. The free edge of said end flap is preferably formed with a pair of spaced rebates intermediate the ends thereof and the lines of weakness preferably extend to said rebates.

The lines of weakness are preferably inclined throughout their lengths to said line of juncture, though they may include portions which extend parallel to said line of juncture. The lines of weakness may extend at 45.degree. to said line of juncture.

To secure the upper of said pair of end flaps to the lower of said pair of end flaps, adhesive is preferably applied to the under surfaces of those portions of the upper end flap defined between each line of weakness and the adjacent end of said upper end flap. That portion of the upper end flap between the pair of lines of weakness provides the tab for engagement in the slot in the lower end flap for effecting reclosing of the carton and said tab-affording portion may be spot-glued to the lower end flap.

According to a second aspect of the invention there is provided a carton-forming blank of the kind specified in which the pair of lines of weakness of the in situ upper of said pair of end flaps each extend from a corner of the side wall associated with said end flap at an inclination to the line of juncture between the end flap and the side wall, that portion of the end flap between said pair of lines of weakness constituting a tab-defining portion.

According to a third aspect of the invention there is provided a carton of the kind specified having a preformed tubular lining sleeve fastened into the carton for protrusion beyond the ends of the side walls thereof and in which the lower of said pair of opposed end flaps extends between and is hingedly connected to a pair of opposed end flaps which are so shaped and have fold lines so arranged that each can be folded inwardly in such way that a triangular part based on the fold line between the flap and the adjoining side wall of the carton is overlapped by a pair of parts of the flap which are doubled back on a fold line, said lower end flap and the pair of end flaps hingedly connected thereto serving, on closure of the carton, to shape the end of the lining sleeve with a pleat in each side and to fold it over to nip the pleated end extremity of the lining sleeve against the upper end flap at its hinged connection with the adjoining side wall of the carton and wherein the pair of lines of weakness of the upper end flap each extend from a corner of the side wall adjoining said upper end flap at an inclination to the line of juncture between the end flap and the side wall, that portion of the end flap between the lines of weakness constituting a tab-defining portion.

The invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a part plan view of one form of carton-forming blank of the kind specified,

FIG. 2 is a perspective view of the upper part of an erected carton formed from the blank of FIG. 1 prior to closure thereof,

FIG. 3 is a plan view of a second form of carton-forming blank of the kind specified,

FIG. 4 is a perspective view of the upper part of an erected carton formed from the blank of FIG. 3 prior to closure thereof, and

FIG. 5 is a view corresponding to FIG. 4 but illustrating partial closure of the carton.

The blank shown in FIG. 1 includes four wall-forming panels 10, 11, 12 and 13 which are provided at one end with lower end flaps (not shown) adapted to be secured together adhesively to form the base of the carton. A glue flap 14 is provided integral with wall-forming panel 10 and an upper end flap 10a, 11a, 12a, 13a is connected to each wall-forming panel 10, 11, 12, 13 by a fold line 15, with fold lines 16 between the glue flap 14 and panel 10 and between adjacent panels 10, 11, 12 and 13. Panel 11a is formed with a pair of lines of weakness 17 each of which extends from the junction between the fold lines 15 and 16 at an inclination of 45.degree. to the fold line 15 between the flap 11a and panel 11.

The free edge of the flap 11a is formed with a pair of triangular cut-outs 18 which are so positioned that the lines of weakness 17 extend to the apices of the cut-outs 18. Each free corner of the flap 11a is cut away as shown in FIGS. 1 and 2. The end flap 11a is thus divided by the lines of weakness into three portions, indicated as A, B and C in FIG. 2. Portion A is a tab-defining portion and portions B and C are attachment portions which have adhesive applied to the underside thereof for closing of the carton.

In closing the carton, end flaps 10a and 12a are first folded inwardly and then flap 13a is folded inwardly followed by flap 11a. The two outermost end flaps 11a and 13a are secured together adhesively to close the carton, the adhesive being applied over the portions B and C of the flap 11a, with possibly pin-point application of adhesive to some parts of the tab portion A. To open the carton, the free edge of the tab portion A is moved away from flap 13a to rupture the lines of weakness 17. To reclose the carton, the free end portion of the tab A is inserted in a reclosure slit 19 in the end flap 13a.

The carton-forming blank shown in FIG. 3 is capable of use with a paper sleeve-like liner (not shown) and has a number of features in common with the blank of FIG. 1 and accordingly like reference numerals indicate corresponding parts of the blank. It is to be noted that the lines of juncture between the various parts of the blank are constituted in part by fold lines indicated by broken lines 20 and partly by spaced perforations indicated by castellated lines 21. It is also to be noted that the line of juncture between each end flap 11a and panel 11 is offset from the lines of juncture between the other flaps and panels; the purpose of this offsetting is to accommodate the liner.

The glue flap 14 is connected by fold lines 20 both to panel 10 and to end flaps 10a and end flap 12a is connected to end flap 13a by a fold line 20. When, therefore, the carton is erected, end flaps 10a, 12a and 13a are foldably connected together. Each flap 10a, 13a has fold lines 21 arranged so that the flap can be folded inwardly in such way that a triangular part 22 whose base is constituted by the fold line between the flap 10a or 12a and the panel 10 or 12 is overlapped by the other two parts 23 and 24 of the flap. When a sleeve-like liner is employed whose ends project beyond the panels 10, 11, 12 and 13, the end flaps 10a, 12a and 13a serve to shape the pleated end of the liner so as to fold it over and nip it against the line of juncture 20 between flap 11a and panel 11.

The flap 11a at the upper end of the carton is formed as described above with lines of weakness 21 inclined at 45.degree. to the line 20 between the flap and the panel and the flap 13a at the upper end of the carton has a reclosure slit 19. Attachment of the end flap 11a to end flap 13a to close the carton, opening of the carton and reclosure thereof are as described above with reference to the embodiment of FIGS. 1 and 2.

Claims

I claim:

1. A carton having side walls, respective end flaps attached to each end of each side wall to provide the top and bottom of the carton and a preformed lining sleeve fastened into the carton for protrusion beyond the ends of the side walls thereof, a pair of opposed end flaps at one end of the carton being disposed in face-to-face relation in the closed condition of the carton, the upper of said pair of end flaps being formed with a pair of lines of weakness whereby, to open the carton, a user may effect a separation operation along said lines of weakness, thereby providing a tab for engagement in a slot in the lower end of said pair of end flaps for effecting reclosure of the carton, and the lower of said pair of opposed end flaps extending between and being hingedly connected to a pair of opposed end flaps which are so shaped and have fold lines so arranged that each can be folded inwardly in such way that a triangular part based on the fold line between the flap and the adjoining side wall of the carton is overlapped by a pair of parts of the flap which are doubled back on a fold line, said lower end flap and the pair of end flaps hingedly connected thereto serving, on closure of the carton, to shape the end of the lining sleeve with a pleat in each side and to fold it over to nip a pleated end extremity of the lining sleeve against the upper end flap at its hinged connection with the adjoining side wall of the carton and wherein the pair of lines of weakness each extend from a corner of the side wall adjoining said upper end flap at an inclination to the line of juncture between the end flap and the side wall, that portion of the end flap between the lines of weakness constituting a tab-defining portion.

2. A carton according to claim 1, wherein each of said lines of weakness extends from the respective corner of a free edge of said end flap.

3. A carton according to claim 2, wherein the free edge of said end flap is formed with a pair of spaced rebates intermediate the ends thereof and the lines of weakness extend to said rebates.

4. A carton according to claim 3, wherein the rebates are triangular and the lines of weakness extend to the apices of the triangles.

5. A carton according to claim 1, wherein the lines of weakness are inclined throughout their lengths to said line of juncture.

6. A carton according to claim 5, wherein the lines of weakness extend at 45.degree. to said line of juncture.

7. A lined carton according to claim 1, wherein a free edge of said upper end flap is chamfered at its ends and is formed with a pair of triangular cut-outs intermediate its ends, the lines of weakness extending to the apices of the triangles and adhesive being applied to the under surfaces of those portions of said flap between each line of weakness and the adjacent end of the flap.

8. A carton as claimed in claim 1, in which the line of juncture between the upper of said pair of end flaps and its side wall is outwardly off-set from the line of juncture between the other of said pair of end flaps and its side wall.