Hollow walled carton structure

Abstract

A folding box comprises hollow side and end walls, each with parallel outer and inner panels and an interconnecting top panel. A pair of gusset panels connected along fold lines between the top side panel, the outer side panel, and the outer end panel, form a continuous, reinforcing bellows interconnecting said panels when the carton is assembled.

Description

BACKGROUND OF THE INVENTION

Hollow walled folding cartons have achieved some degree of popularity for packaging certain items, such as pen and pencil sets, which are advantageously displayed on a sales counter or the like, framed within the hollow wall enclosure. Such hollow walled boxes are exemplified by the structure of my own U.S. Pat. No. 2,714,483 granted Aug. 2, 1955, and include hollow side and end walls, each comprising upright inner and outer panels and an interconnecting top panel. In the structure of that patent, the outer side and end walls are interconnected by a gusset panel having a diagonal fold line, which in the folded carton is embraced by the hollow end wall. This structure has proven to be highly successful but there have been experienced some structural weaknesses in that the hollow side wall is not rigidly braced against outward collapse.

OBJECTS OF THE INVENTION

It is an object of this invention to provide a hollow walled folding carton, the corner structure of which is rigid and durable.

It is a further object of this invention to provide a hollow walled folding carton which lends itself readily for high production machine folding.

Other objects and advantages of this invention will become apparent from the description to follow when read in conjunction with the accompanying drawing.

BRIEF SUMMARY OF THE INVENTION

In carrying out this invention I provide a hollow walled carton having a bottom panel framed by hollow end and side structures formed of parallel outer and inner panels, which are upright in the completed box, and an interconnecting top panel. Flaps at the ends of the inner panels are adhered to the bottom panel from a fold line spaced from the outer panel to complete and secure hollow side walls in such box configuration. In the corner structure, a gusset panel having a diagonal fold line interconnects the adjacent outer panels of the end and side structures and a second gusset panel, also with a diagonal fold line unifies the structure by connecting the first gusset to the end of the top panel. Hence, there is a continuous bellows structure connecting, reinforcing and tying together the top side panel through tabs on the ends thereof, and the outer panels of both the side and end structures. In assembly, these bellows configurations, together with the small tabs on the ends of the top side panels to which they are tied, are enclosed and secured within the hollow end walls, with locking tabs on the sides of the inner end panels engaged behind the ends of the inner side panels. The result is a rigid, well reinforced corner structure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a plan view of a partially folded carton blank embodying features of this invention;

FIGS. 2 and 3 are partial views in perspective showing the carton in progressive stages of assembly; and

FIG. 4 is a perspective view of the assembled carton.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to FIG. 1 the box blank 10 of this invention comprises a bottom panel 12 bounded by side fold lines 14 and end fold lines 16. Articulated to the bottom panel from the fold line 14 is a series of wall panels making up the side wall structure and including an outer side wall panel 18, a top side wall panel 20 an inner side wall panel 22 and a base flap 24 to which a suitable adhesive 26 is applied.

Also articulated to the bottom panel 12 from fold line 16 is a series of panels making up the end wall construction and comprising an outer end panel 28, a top end panel 30, an inner end panel 32 with side locking tabs 34, and a base flap 36.

The ends of the top side wall panels 20 extend beyond the inner side panels 22 to form small tabs 40, which are separated from the inner panels by cuts 42. Hingedly connected to the outer end and side walls 18 and 28 is a first gusset panel 44 having a diagonal fold line 46 therein. A second gusset panel 48 with a similar diagonal fold line 50 is hingedly connected between the first gusset panel 44 and the tab 40 at the adjacent end of the top side panel 20.

Prior to assembly, the series of side wall panels 20, 22 and 24 are folded inwardly along the fold line 52 between the outer and topside wall panels 18 and 20 and the base 24 flap is adhered to the face of the bottom panel 12, as shown at the lower portion of FIG. 1. In this position, the second gusset panel 47 overlies the first gusset panel 44 to form a continuous bellows connection, tying the outer side wall panel 18 to both the top side wall panel tab 40 and the outer end wall panel 28. The box blanks may be shipped as so folded and delivered to conventional box making machinery where assembly is completed.

Referring now to FIGS. 2 and 3, assembly commences by folding the side wall assembly 18, 20 and 22 along the bottom panel fold line 14 to upright position as shown, and the continuous, double gusset panels are collapsed along the diagonal fold lines 46 and 50 to the double bellows configuration while the series of panels making up the end wall are initially folded upward, again along the bottom panel fold line 16.

When the outer end panel is upright, as shown in FIG. 3, the sidewall structure is rigidly supported against collapse, by reason of the double bellows reinforcement 44, 48. That is, outward collapse of the hollow side wall is resisted by the triangular bellows connection 48 to the top panel tabs 40 and inward collapse is resisted by the double bellows connection 44 to the side edges of the outer end panel 28.

When the end wall structure 28, 30, and 32 is folded further, the top end panel overlies the tabs 40 and nested double bellows 44 and 48. The inner end panel 32 encloses such tabs and bellows and the small locking tabs 34 are inserted along the edges 42 of the inner side panels 22 in the assembled carton shown in FIG. 4.

While this invention has been described in conjunction with a preferred embodiment thereof, it is obvious that modifications and changes therein may be made by those skilled in the art without departing from the spirit and scope of this invention as defined by the claim appended hereto.

Claims

What is claimed as invention is:

1. A hollow walled carton corner comprising:

a bottom panel having perpendicular end and side fold lines;

outer, top and inner side panels, respectively, connected to said bottom panel along said side fold line with parallel fold lines therebetween;

the length of said inner side panel terminating short of the end of said bottom panel;

a flap articulated to said inner side panel;

means adapted to secure said flap to said bottom panel;

a tab extending inward from the end of said top side panel to overlie said bottom panel;

outer, top and inner end panels, respectively, connected to said bottom panel along said end fold line with parallel fold lines therebetween;

the improvement comprising:

a first gusset panel having a diagonal fold line articulated to said outer end and side panels; and

a second gusset panel having a diagonal fold line articulated to said top side panel tab and said first gusset panel.

2. The hollow walled carton corner defined by claim 1 including:

a locking tab articulated to the said of said inner end panel;

so that when said box end structure is erected:

said top end panel overlies said tab; and

said locking tab is inserted normal to and against the end of said inner side panel.

3. The hollow walled carton corner defined by claim 2 wherein when said box end structure is erected:

said first and second gusset panels are folded together as articulated and along said diagonal fold lines to be disposed against with said outer end panel.