Roll-top closure pack

Abstract

A pack that includes a bottom, a front side, a back side, and a top opening for allowing insertion of articles to, and removable from, inside the pack. The front and back sides of the pack are adjacently affixed to each other at their left and right edges. The pack further includes a closure arrangement to close the top opening, such closure arrangement including an upper front flap, adjacently connected to the front side and an upper back flap adjacently connected to the back side. The pack is closed when the upper front flap and the upper back flap are pressed against each other and then rolled down together along the pack until a rolled state of the upper front flap and the upper back flap is reached. The pack further includes an expansion arrangement allowing, on one hand, separation of the front side from the back side when the expansion arrangement is in a open state and, on the other hand, abutment of the front side to the back side when the expansion arrangement is in a closed state, the expansion arrangement having a lower extremity and a upper extremity. The upper extremity of the expansion arrangement is positioned between the junction of the front side and the upper front flap and the junction of the back side and the upper back flap.

1 . A pack comprising:
 a bottom, a front side, a back side, and a top opening for allowing insertion and removable of articles inside or from the pack;   said front side and said back side having respective edges adjacent to each other;   a closure arrangement to close said top opening;   said closure arrangement comprising an upper front flap, adjacently connected to said front side and an upper back flap adjacently connected to said back side;   said closure arrangement being movable between a first position and a second position, in said first position, the pack is open and in said second position, the pack is closed;   in the first position of said closure arrangement, said upper front flap and said upper back flap are pressed against each other and are together rolled along the pack into rolled state of the upper front flap and the upper back flap;   an expansion device movable between an open state and a closed state;   in said open state, the expansion device allowing separation of the front side from the back side and, in said closed state, the front side and the back side are in abutment;   said expansion device having a lower extremity and an upper extremity;   said upper extremity of said expansion device being positioned between a junction of said front side and said upper front flap and a junction of said back side and said upper back flap.   
   
   
       2 . A pack according to  claim 1 , wherein:
 said expansion device comprises a slit provided between said front side and said back side.   
   
   
       3 . A pack according to  claim 2 , wherein:
 said expansion means device comprises a gusset;   said gusset limits opening of said slit when said expansion device is in the open state and provides a waterproof quality to said slit when said expansion device is in closed state.   
   
   
       4 . A pack according to  claim 1 , wherein:
 said expansion device further comprises a slide fastener.   
   
   
       5 . A pack according to  claim 1 , wherein:
 said expansion device includes a structure connected to the back side and structures connected to respective ones of a left upper edge and a right upper edge of the front side of the pack.   
   
   
       6 . A pack according to  claim 1 , wherein:
 said upper front flap comprises a front supple portion and a front firm portion, and said upper back flap comprises a back supple portion and a back firm portion;   said front firm portion and said back firm portion are shaped as elongated strips, each of said strips having a length at least equal to a width of the front side;   said front supple portion and said back supple are shaped as elongated strips, each of said strips having a breadth at least equal to a breadth of the front firm portion.   
   
   
       7 . A pack according to  claim 6 , wherein:
 in said first position of said closure arrangement, the front firm portion and the back firm portion are pressed against each other and are folded together against the back supple portion, thereby being in a rolled state of the upper front flap and the upper back flap.   
   
   
       8 . A pack according to  claim 6 , wherein:
 the front firm portion includes a stiffener and the back firm portion comprises a stiffener.   
   
   
       9 . A pack according to  claim 7 , wherein:
 the closure arrangement further comprises a retaining mechanism to retain the upper front flap and the upper back flap in their rolled state.   
   
   
       10 . A pack according to  claim 9 , wherein:
 said retaining mechanism comprises a pair of tensioning straps, each of said tensioning straps being attached on the front supple portion.   
   
   
       11 . A pack according to  claim 1 , further comprising:
 a handle to allow the pack to be carried with a hand of a user.   
   
   
       12 . A pack according to  claim 1 , further comprising:
 a pair of shoulder straps to allow the pack to be carried by shoulders of a user.   
   
   
       13 . A pack according to  claim 1 , wherein:
 the lower extremity of the expansion device is positioned in a vicinity of the bottom of the pack.