Container having corner post for top to bottom stacking

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a self-locking container formed from a unitary blank of paperboard or fibre, and more particularly to a container having provision for stiffening the comers thereof to provide good stacking properties.

2. Description of the Prior Art

Heretofore, structures for stiffening containers for vertical stacking have required glued flaps (Fallert 2,857,090), a multiplicity of extra panels requiring extra paperboard (Agler, 2,963,211) or extra thicknesses of board stock in the end panels (Morgan 3,116,867).

SUMMARY OF THE INVENTION

The structure according to the present invention comprehends a comer post for a self-locking container, said comer post having elements flanking both the side and end panels and having bearing contact with a top panel and the bottom panel of the container, to the end that the container has good stacking properties.

DRAWINGS

FIG. 1 shows a unitary cut and scored paperboard blank for forming into a container according to the present invention;

FIG. 2 is an isometric view showing some of the steps in setting up the container;

FIG. 3 is a vertical section taken along the line 3-3 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is a horizontal section taken along the line 4-4 of FIG. 2 looking in the direction of the arrows;

FIG. 5 is an isometric view of the container with the closure flap thereof in position;

FIG. 6 is a vertical section taken essentially along the line 6-6 of FIG. 5 looking in the direction of the arrows; and

FIG. 7 is a vertical section taken along the line 7-7 of FIG. 5 looking in the direction of the arrows.

A unitary blank of paperboard or similar material for forming the container according to the present invention is denoted by the reference numeral 10 and comprises a bottom panel 11, opposed side panels 12 foldably connected to bottom panel 11 along score lines 13. Opposed end panels 14 are foldably connected to bottom panel 11 along score lines 16.

Each of the side panels 12 is provided at the ends thereof with flaps 17 foldably connected thereto along score lines 18. Flaps 17 are adapted to be folded at right angles to side panels 12 along the inside of the end panels 14 when the latter are folded to erect position.

End panels 14 are each provided with a top panel 21 hingedly attached thereto along a score line 22. Each end of the top panels 21 has a comer post extension 23 therefrom, the latter including a side element 27 foldably connected to top panel 21 along a score line 24. An end element 26 is hingedly attached to a side edge of element 27 along a score line 28 and extends downward adjacent the inside of a related side panel flap 17.

Elements 26 and 27 provide structure for lending stiffness to the comers of the container as well as good stacking qualities. Moreover, elements 26 and 27 provide additional support for the top panel 21 when the same is in the setup position seen in the several views.

In the setup position of the container, element 26 is adapted to stand along the flap 17 of sidewall 12, while element 27 is '2 adapted to stand along the inner face of sidewall 12, as seen more particularly in FIG. 4.

Structure is provided for locking element 26 in position if desired, and to this end the bottom panel 11 may be scored and crushed as at 32 and 33, (commonly known as a “Walker Lock”) at the comers thereof, while element 26 is provided with a locking tab 31 adapted to be in locking engagement with “Walker Lock” 32.

It will be seen from the description thus far, that the elements 26 and 27, together with the side panel 12 and the flaps 17 thereof, provide extra thickness layers at the corner of the container. By reason of element 27 having good bearing against bottom panel 11, and element 26 having good bearing both against bottom panel 11 and against the underside of top panel 21, good vertical stiffness is provided.

Top panel 21 also enables the container to be stacked one atop another. If desired, the container may be open-topped for display of the contents thereof. If desired, however, it can be provided with a top closure panel 36 foldably connected by a fold line 37 to one of the side panels 12. A tuck-in flap 38 is foldably connected along a fold line 39 to closure panel 36.