Self-supporting and spill resistant food carton

A one piece blank is provided which may be erected into a generally hollow self-supporting food carton. The blank includes a base panel having first and second opposing score line edges, and first and second upright panels which are hingedly connected to corresponding scored edges of the base panel. The base panel also includes connecting side edges which extend between the opposing scored edges. Each upright panel includes bottom edge sections which extend outwardly from inwardly spaced locations on the connecting side edges. Cuts are provided which extend from the intersection of the connecting side edges and the bottom panel sections to the scored base panel edges. The carton is assembled by pivoting the first and second upright panels about the scored base edges, and attaching the upright panels at outwardly extending lateral edges. The arrangement and placement of cuts raises the base relative to the upright panels to provide arcuate supports for the carton.

DESCRIPTION 
1. Technical Field 
This invention relates generally to the art of folding paperboard cartons, 
and more particularly to cartons useable as food and beverage containers, 
blanks for their formation and processes for their manufacture and use. 
2. Background Art 
Cartons of the general type contemplated by the invention are basically 
well known and have been used for many years. Such cartons have found 
widespread use in restaurants, particularly those known as "fast food" 
restaurants for the dispensing of food such as french fried potatoes, 
meat, fish and poultry products. For purposes of accommodating their 
various applications, such cartons have been provided in a diversity of 
geometric configurations with both open and closed top end constructions. 
Carton constructions of this type are represented by U.S. Pat. No. 
3,684,157 to Mendez and U.S. Pat. No. 4,267,955 to Struble. 
The present invention is directed to an improved carton which has 
self-supporting, spill resistant as well as a more structurally sturdy 
construction than provided in the prior art. It will be appreciated that a 
carton structure with improved sturdiness and tilt tolerance is most 
desirable in "fast food" applications where containers are used for 
serving as well as packaging. 
Accordingly, it is a broad object of the present invention to provide an 
improved food carton of economical design which is structurally sturdy. 
A more specific object of the invention is to provide a food carton which 
has self-supporting and spill resistant features in a structurally 
uncomplex design. 
DISCLOSURE OF THE INVENTION 
In the present invention, these purposes, as well as others which will be 
apparent, are achieved generally by providing a blank which may be erected 
into a generally hollow upright non-collapsible, self-supporting carton. 
The carton blank includes a base panel having first and second generally 
opposing edges which are bordered by score lines, and first and second 
upright panels which are, respectively, hingedly connected to 
corresponding scored edges of the base panel. The base panel also includes 
connecting side edges which extend between the opposing scored edges. In 
the erected carton, the base panel forms a closed flat carton end, and the 
first and second upright panels, when secured together at opposing lateral 
edges, form the carton boundary wall. 
Two features in the blank contribute to the structural integrity and 
sturdiness of the carton. Firstly, the first and second upright panels 
include bottom edge sections which extend outwardly from inwardly spaced 
locations on the connecting side edges. Secondly, cuts are provided in the 
bottom edge sections, extending from the intersection of the connecting 
side edges and the edge sections to the scored base panel edges. In the 
erected carton, the connecting side edges of the base are oriented 
inwardly relative to the base plane to provide stabilizing supports. 
Further structural rigidity in the carton is obtained by employing a base 
panel which has a greater longitudinal width than the base dimension of 
the carton. During assemblage of the carton this result is obtained by 
biasing lateral edges of the upright panels against connecting side edges 
of the base panel. A moisture venting feature is provided by recessing the 
connecting side edges into the carton to define openings between the base 
panel and upright panels. This recessed side edge arrangement also 
provides a shelf which facilitates separation of the cartons when they are 
stacked in nested relation. 
In a preferred embodiment of the invention, the carton has an oval 
configuration, and the base panel has arcurate connecting side edges which 
are recessed into the carton at an approximately thirty degree angle. The 
oval configuration of the carton is maintained by outward pressure applied 
to the upright panels by the recessed edges. This effect is pronounced 
when the cartons are stacked in nested relation with supports in the 
cartons contacting and pressing downward on the side edges of underlying 
cartons. In this embodiment, the first upright panel is also provided with 
a wider longitudinal dimension than the second upright panel. The relative 
dimensions of the upright panels position connecting side seams in the 
carton offset towards the second upright panel for further carton 
stability. 
In a further preferred embodiment of the invention, each upright panel is 
provided with a closure flap which flexes inwardly at upwardly opening 
arcuate score lines. 
Other objects, features and advantages of the present invention will be 
apparent when the detailed description of the preferred embodiments of the 
invention are considered in conjunction with the drawings, which should be 
construed in an illustrative and not limiting sense, as follows:

BEST MODE OF CARRYING OUT INVENTION 
Referring now to the drawings, a blank and a self-supporting and spill 
resistant carton formed from the blank, respectively designated 10,20, are 
illustrated in FIGS. 1-5. The blank 10 comprises a base panel 30 which 
forms a closed end in the erected carton, and first and second upright 
panels 50,60 which form an enclosing boundary wall in the carton. For fast 
food applications, the carton blank is preferably fabricated of 
conventional folding carton paperboard in the 12 pt. to 16 pt. range and 
where appropriate grease resistant or laminated board. 
The base panel 30 includes first and second opposing edges 32,34 which are 
bordered by score lines, and connecting side edges 36,38 which have an 
outwardly oriented arcuate configuration. Each connecting side terminates 
in angled legs 40,42 which respectively meet the first and second opposing 
edges 32,34 of the base panel. 
The first and second upright panels 50, 60 each include bottom edges 52,62, 
a pair of opposing lateral edges 54,64 which extend outwardly from the 
bottom edge, and top end edges 56,66. 
Each bottom panel edge 52,62 includes opposing sections 53,63 which extend 
outwardly from respective connecting side legs 40,42 of the base panel 30. 
For reasons which will be discussed hereinafter, the panel sections 53,63 
are spaced substantially like distances inwardly from scored base panel 
edges 32,34, and provided with cuts, designated by the letter C in FIG. 1, 
which extend from the intersection of legs 40,42 and bottom panel sections 
53,63 to scored base panel edges 32,34. At their exterior ends, bottom 
panel edges 52,62 are provided with inwardly angled sections 53a, 63a for 
purposes which will also be discussed below. 
FIGS. 2-5 show the blank of FIG. 1 erected to form a generally oval 
non-collapsible container 20 with a closed bottom end and open top end. As 
may be seen with reference to FIG. 1, the first upright panel 50 includes 
areas designated 55 which receive glue or other conventional adhesive for 
securing the first and second upright panels 50,60 together at opposing 
lateral edges 54,64. It will be appreciated that upright panels 50,60 
pivot about score lines 32,34 to facilitate construction of the flat 
bottom carton 20. According to an important feature of the invention, the 
bottom edges 52,62 of the upright panels project outwardly from base panel 
30 to provide arcuate supports 70, best shown in FIG. 3. Arcuate supports 
70 result from the arrangement of cut scores C which cause the bottom 
edges 52,62 of the upright panels 50,60 to be spaced downwardly relative 
to the base panel 30 when the carton is erected. Inwardly angled section 
53a, 63a of the upright panel bottom edges further contribute to define 
the arcuate supports 70 by depending downwardly below base panel 30 in the 
erected carton, see FIG. 4. 
Further structural rigidity in the carton 20 is obtained by dimensioning 
the erected carton so that it has a longitudinal width in its base area, 
which is smaller than the width of base panel 30, thereby biasing opposing 
lateral edges 54,64 of the upright panels against connecting side edges 
36,38 of the base panel 30. As best shown in FIG. 3, the side edges 36,38 
are recessed into the scoop on approximately a thirty degree angle to 
provide openings 36a, 38a between the base panel 30 and upright panels 
50,60. It will be recognized that the orientation of the angled legs 40, 
42 relative to opposing edges 36, 38 of the connecting sides define the 
vent openings 36a, 38a, see FIG. 5. These openings provide venting 
channels from the bottom to top of the carton, allowing hot moist air to 
escape and maintain the crispness of packaged foodstuffs. 
Still further advantage is obtained by providing the first upright panel 50 
with a wider longitudinal dimension than the second upright panel 60. The 
relative dimensions of the upright panels position connecting side seams 
74 offset towards the second upright panel 60 for enhanced carton 
stability. 
In practice the carton 20 is provided to the consumer in the erected form 
illustrated FIG. 2. Its oval configuration, and outwardly tapered side 
walls facilitate storage in stacked or nested fashion, and ready 
separation for use, see FIG. 10. In this connection, it will be 
appreciated that recessed side edges 36, 38 define a shelf which 
facilitates separation of stacked cartons. 
The recessed side edges also exert outward pressure on the upright panels 
50, 60 to maintain the oval configuration of the carton. This effect is 
pronounced when the cartons are stacked in nested relation with the 
supports 70 of each carton contacting and pressing downward on the side 
edges 36, 38 of an underlying carton. It will be appreciated that 
provision of a base panel 30 which is wider than the longitudinal 
dimension of the carton base, and the downward pressure applied to the 
side edges 36, 38 by the nesting arrangement coact to maintain the side 
edge edges at approximately thirty degree angles. 
FIGS. 6-9 illustrate an alternative blank embodiment, designated 100, for 
forming a self-supporting and spill resistant container 200 in accordance 
with the invention. Referring to FIG. 6, it will be seen that the blank 
includes a base panel 130 and first and second upright panels 150,160, 
corresponding to the arrangement of FIG. 1. This alternative embodiment of 
the invention differs in the provision of closure flap panels 180 which 
are joined to the first and second upright panels 150,160 at inwardly 
scalloped or arcuate score lines 182. 
In the erected carton 200, illustrated in FIGS. 7-9, it is seen that 
closure flap panels 180 flex inwardly to provide closure flaps. 
Advantageously, the closure functions to prevent spillage as well as 
insulate the carton against heat loss. 
From the foregoing, it will be appreciated that the present invention 
provides a food carton which achieves the objectives stated heretofore. In 
particular, a food carton construction is provided which is sturdy and 
durable, and which may be readily erected from a one piece carton blank. 
Advantageously, improved sturdiness and spill resistance in the carton is 
obtained by providing arcuate supports 70 which stabilize the carton. In 
this connection upright panels 50,60 are provided with inwardly angled 
sections 53a, 63a which depend downwardly from base panel 30 in the 
erected carton. Further sturdiness in the carton is obtained by biasing 
the base panel connecting edges 36, 38 against the upright panels when 
erecting the carton. Recessing side edges 36,38 into the carton provides 
openings 36a, 38a for venting moisture and defines a shelf which 
facilitates separation of nested cartons. The recessed side edges also 
exert outward pressure on the upright panels 50, 60 to maintain the oval 
configuration of the carton. 
Numerous modifications are possible in light of the above disclosure. For 
example, the drawings show closure flaps 180 which partially close the top 
end of the container 200. It will be appreciated that the construction of 
the closure flaps may vary to provide for full carton closure or to 
incorporate vent openings. In similar manner, although the cartons 20, 200 
are illustrated as having generally oval configurations, other geometric 
configurations are within the scope of the disclosure. It is to be 
understood, therefore, that the above-described embodiments are merely 
illustrative, and other embodiments may be devised by those skilled in the 
art, without departing from the spirit or scope of the present invention, 
as set forth in the appended claims.