Packaging box assembly

Abstract

A packaging box assembly includes a box body and a cover body. The box body has a box base plate connected to four box side plates, and extension plates that have the same with as and that are connected respectively and foldably to the box side plates. The box body defines a small volume space and the cover body surrounds the box side plates when the extension plates are folded over the box side plates. The box body defines a large volume space and the cover body surrounds the extension plates when the extension plates are unfolded. In a preferred embodiment, an auxiliary case is attached to the box base plate of the box body.

1 . A packaging box assembly comprising:
 a box body including a box base plate having four box lateral sides respectively connected to four box side plates, said box side plates respectively having movable lateral end disposed away from and parallel to said box lateral sides of said box base plate, respectively, and extension plates having the same width as said box side plates and connected respectively and foldably to said movable lateral ends, two opposite ones of said box side plates each having two opposite box lateral ends connected respectively to box reinforcing plates, the remaining two of said box side plates each having box adhesion parts which are proximate to two opposite box lateral ends thereof and to which said box reinforcing plates can be attached after being folded; and   a cover body including a cover base plate having four cover lateral sides respectively connected to four cover side plates, two opposite ones of said cover side plates each having two opposite cover lateral ends connected respectively to cover reinforcing plates, the remaining two of said cover side plates each having cover adhesion parts which are proximate to two cover lateral ends thereof and to which said cover reinforcing plates can be attached after being folded,   wherein, when said extension plates are folded over said box side plates, said box body defines a small volume space that can receive a small size article therein, and said cover body surrounds said box side plates, and   wherein, when said extension plates are unfolded, said box body defines a large volume space that can receive a large size article therein, and said cover body surrounds said extension plates.   
   
   
       2 . The packaging box assembly of  claim 1 , wherein
 said box body further includes a pair of box insert slots respectively extending through two of said box lateral sides of said box base plate where said two of said box side plates having said box reinforcing plates are connected to said box base plate, and locking tongue plates associated respectively with said box insert slots, and wherein   said packaging box assembly further comprises an auxiliary case which includes a case base plate having four case lateral sides respectively connected to four case side plates, two opposite ones of said case side plates each having two opposite case lateral ends connected respectively to case reinforcing plates, the remaining two of said case side plates each having two opposite case lateral ends provided respectively with case adhesion parts to which said case reinforcing plates are attached after being folded, said auxiliary case further including case tabs projecting respectively from distal ends of two opposite ones of said case side plates connected to said four case lateral sides of said case base plate, said case tabs respectively having case insert slots extending therethrough at said distal ends, and wherein,   said auxiliary case is disposed over said box base plate of said box body, said case tabs being inserted respectively into said box insert slots in said box base plate, said locking tongue plates being inserted respectively into said case insert slots so that said auxiliary case is fixed to said box base plate.   
   
   
       3 . The packaging box assembly of  claim 1 , wherein each of said box body and said cover body is made from corrugated paper. 
   
   
       4 . The packaging box assembly of  claim 1 , wherein said cover body further includes fold lines in two of said cover side plates connected to two opposite ones of said cover lateral sides of said cover base plates, said fold lines in each of said cover side plates extending obliquely and convergingly from two corner points where each of said two opposite ones of said cover lateral sides meet said cover reinforcing plates and said cover lateral ends of the respective one of said cover side plates. 
   
   
       5 . The packaging box assembly of  claim 1 , wherein said box body is composed of two foldable plates each having first and second plate components, each of said first and second plate components having a sub-base, a sub-side plate having a bottom end connected to a top end of said sub-base, and a sub-extension plate having a bottom end connected to a top end of said sub-side plate, said sub-side plate of each of said first and second plate components having first and second sides between said top and bottom ends of said sub-side plate, said sub-side plate of said first plate component being connected to said second side of said sub-side plate of said second plate components, said second side of said sub-side plate of said first plate component having a connecting plate projecting therefrom in a direction away from said first side, said two foldable plates being connected to each other, said connecting plate of said first plate component of one of said foldable plates being adhered to said first side of said second plate component of the other one of said foldable plates, said sub-bases of said first and second plate components are folded to overlap each other and are adhered together. 
   
   
       6 . The packaging box assembly of  claim 5 , wherein said sub-side plate of each of said first and second plate components further has an insert slot at said top end thereof where said sub-side plate is connected to said sub-base of a respective one of said first and second plate components, and a locking tongue plate associated with said insert slot of said sub-side plate. 
   
   
       7 . A packaging box assembly comprising:
 a box body including a box base plate having a plurality of box lateral sides, a plurality of box side plates projecting respectively from said box lateral sides and connected to each other, a pair of box insert slots respectively extending through said box base plate, locking tongue plates associated respectively with said box insert slots; and   an auxiliary case which includes a case base plate having a plurality of case lateral sides, a plurality of case side plates projecting respectively from said case lateral sides, and two case tabs projecting respectively from two opposite ones of said case side plates and each having a case insert slot, said auxiliary case being attachable to said box body, said case tabs and said case insert slots being interlockable with said box insert slots and said locking tongue plates to attach said auxiliary case to said box body.