Paper lunch box

A paper lunch box includes a box body, at least one longitudinal partition member and at least one transverse partition members respectively installed in the box body to support the box body in shape and to separate the holding space of the box body into separated compartments, the box body being formed of a patterned cardboard folded up into a rectangular container having vertical peripheral walls of double-layer construction, the transverse and longitudinal partition members being formed of a respective patterned cardboard, each having a .andgate.-like cross section and reinforcing end flaps for mounting.

BACKGROUND OF THE INVENTION 
The present invention relates to a paper lunch box, and more particularly 
to such a paper lunch box, which has multiple compartments for holding 
different food and vertical peripheral walls of double-layer design. 
FIG. 1 shows a conventional paper lunch box. This structure of paper lunch 
box 1 comprises a base panel 2, four vertical side panels 3, and four rim 
flaps 4. Because the holding space of the paper lunch box 1 is an open 
space, different food cannot be separately kept in the paper lunch box 1. 
Further, because the vertical side panels 3 are of a single layer design, 
the paper lunch box 1 tends to be deformed. FIGS. 2A and 2B show another 
structure of paper lunch box according to the prior art. This structure of 
paper lunch box is formed of a patterned cardboard 10. The patterned 
cardboard 10 comprises bottom panels 11, 12 and 13, side panels 110, 111, 
112, 113, 114, 115 and 116, partition panels 120, 121 and 123, and 
extension flaps 14. After the patterned cardboard 10 has been folded up 
and adhered into shape, the finished paper lunch box provide three 
separated compartments for holding different food. However, this structure 
of paper lunch box still has drawbacks as outlined hereinafter. 
1. Because the side panels 110, 111, 112, 113, 114, 115 and 116 are of a 
single-layer construction, the paper lunch box is not very strong for 
carrying much food. 
2. The paper lunch box provides only a limited number of compartments for 
holding different food. 
3. The partition panels 120, 121 and 123 cannot support the side panels 
110, 111, 112, 113, 114, 115 and 116 firmly in shape when the paper lunch 
box receives a compressive force. 
SUMMARY OF THE INVENTION 
It is one object of the present invention to provide a paper lunch box, 
which has a strong structural strength. It is another object of the 
present invention to provide a paper lunch box, which provides multiple 
separated compartments for holding different food. According to the 
present invention, the paper lunch box comprises a box body, at least one 
longitudinal partition member and at least one transverse partition 
members respectively installed in the box body to support the box body in 
shape and to separate the holding space of the box body into separated 
compartments, the box body being formed of a patterned cardboard folded up 
into a rectangular container having vertical peripheral walls of 
double-layer construction, the transverse and longitudinal partition 
members being formed of a respective patterned cardboard, each having a 
.andgate.-like cross section and reinforcing end flaps for mounting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. from 3 through 6, a paper lunch box in accordance with 
the present invention is shown comprised of a box body 601, two transverse 
partition members 401, and a longitudinal partition member 501. The box 
body 601, the transverse partition members 401 and the longitudinal 
partition member 501 are made of respective patterned cardboards 60, 40 
and 50. The patterned cardboards 60, 40 and 50 are bent into shape and 
adhered together. The transverse partition members 401 and the 
longitudinal partition member 501 each have a .andgate.-like cross 
section. The longitudinal partition member 50 (501) comprises two locating 
notches 52 at two opposite lateral sides, and reinforcing end flaps 51 at 
two opposite ends. The transverse partition members 40 (401) each comprise 
a plurality of reinforcing end flaps 41 at two opposite ends. The box body 
60 (601) comprises a rectangular base panel 65, four side panels 61 
respectively extended from the four sides of the base panel 65, four 
peripheral reinforcing panels 62 respectively extended from the side 
panels 61, four inner rim portions 610 respectively connected between the 
side panels 61 and the reinforcing panels 62, four outer rim portions 620 
respectively connected between the inner rim portions 610 and the 
reinforcing panels 62, a longitudinal line of cut L1 formed on the base 
panel 65, two transverse lines of cut L2 respectively formed on the base 
panel 65 and perpendicularly extended from the longitudinal line of cut L1 
in reversed directions, and reinforcing strip portions 63 respectively 
formed integral with the base panel 65 along two opposite sides of each of 
the lines of cut L1 and L2. After the patterned cardboard 60 having been 
folded up, the reinforcing panels 62 are respectively adhere to the side 
panels 61, and the outer rim portions 620 are respectively adhered to the 
inner rim portions 610 (see FIG. 4), and then the longitudinal partition 
member 501 and the transverse partition members 40 (401) are respectively 
adhered to the reinforcing strip portions 63 and side panels 61 of the box 
body 601. When installed, the reinforcing end flaps 51 of the longitudinal 
partition member 501 are adhered to two opposite side panels 61 of the box 
body 601 on the inside, the reinforcing end flaps 41 of the transverse 
partition members 401 are respectively adhered to one corresponding side 
panel 61 of the box body 601 and the inside wall of the longitudinal 
partition member 501 around the locating notches 52. 
Because the partition members 401 and 501 have a substantially 
.andgate.-like cross section and are used as stretcher means to support 
the side panels 61 of the box body 601 in shape, the structure of the 
lunch box is strong. Because the reinforcing panels 62 are respectively 
adhere to the side panels 61 and the outer rim portions 620 are 
respectively adhered to the inner rim portions 610, the vertical 
peripheral walls of the paper lunch box have a double-layer construction, 
which is strong enough against deformation. Further, the partition members 
40 and 50 separate the holding space of the paper lunch box into separated 
compartments for holding different food. 
FIGS. 7 and 8 show two alternate forms of the present invention. In FIG. 7, 
the transverse partition members 401 have different lengths, the 
longitudinal partition member 501 is connected between the longer 
transverse partition member 401 and one side panel of the box body 601, 
and the shorter transverse partition member 401 is connected between the 
longitudinal partition member 501 and one side panel of the box body 601. 
In FIG. 8, two transverse partition members 401 and two longitudinal 
partition members 501 are installed in the box body 601. 
It is to be understood that the drawings are designed for purposes of 
illustration only, and are not intended for use as a definition of the 
limits and scope of the invention disclosed.