Fold-top closure and method therefor

A leak-proof container comprising:

• a flexible container having an upper portion, said upper portion having front and back sheets of flexible material, each said sheet having lateral sides and a top edge, said sheets joined together at said sides, said top edges in detached planar apposition,
• a semi-rigid splint attached to said back sheet below said top edge extending approximately from one side to the other of said back sheet, said splint having upper and lower edges, said splint further having a linear rest position and a physical memory which urges it to return to said linear rest position after being flexed,
• an upper section of said sheets bounded by said top edge on top and by said upper edge of said splint on bottom, and a lower section of said sheets having a top boundary at said upper edge of said splint,
• said sheets having an open configuration in which said splint is flexed and said sheets are separated defining an opening for said container, said opening large enough to admit a hand therethrough into said container,
• said sheets having a closed configuration defined by a first fold formed by folding said upper section of said sheets forward over said splint at a first fold line coincident with the upper edge of said splint thereby bringing said upper section into apposition with said splint, and a second fold formed by folding said upper and lower sections of said sheets forward at a second fold line coincident with said lower edge of said splint thereby folding said upper section back upon itself, thereby defining a reverse fold of said upper section converse to said first fold adjacent said lower edge of said splint, said reverse fold trapped between said splint and said lower section of said sheets, and
• a fastening flap attached to said front sheet below said splint, said fastening flap having a securing panel, said back sheet further including a cooperating panel, in said closed configuration said securing panel of said fastening flap demountably secured to said cooperating panel of said back sheet so that said front and back sheets and said splint are secured in said closed configuration.

A method for leak-proof closing of a container, which comprises:

• a. joining together sides of a front sheet of flexible material with sides of a back sheet of flexible material, the sheets having bottom portions for attachment to the container, so that a top edge of each sheet is adjacent but not sealed to the other top edge,
• b. attaching to the back sheet below the top edge thereof a semi-rigid splint extending approximately from one side of the back sheet to the other side, such that a passage to the container is provided by flexing the splint and separating the sheets,
• c. folding an upper section of the sheets, bounded by the top edge of the sheets on top and by an upper edge of the splint on bottom, over the splint at a first fold line coincident with the upper edge of the splint thereby forming a first fold and bringing the upper section of the sheets into apposition with the splint,
• d. folding the upper section of the sheets and a lower section of the sheets forward at a second fold line coincident with a lower edge of the splint, the lower section of the sheets bounded on top by the upper edge of the splint, thereby forming a reverse fold of the upper section of the sheets adjacent the lower edge of the splint and converse to the first fold and trapping the reverse fold between the splint and the lower section of the sheets, and
• e. securing the sheets and the splint in their folded configuration.

A method for leak-proof closing of a container, which comprises:

• a. joining together sides of a front sheet of flexible material and of a back sheet of flexible material of an upper portion of a flexible container, leaving a top edge of each sheet apposite but not sealed to the other top edge,
• b. attaching to the back sheet below the top edge thereof and extending approximately from one side of the back sheet to the other side a semi-rigid splint having in cross-section a thickness and an elongated width relative to the thickness, the splint further having a linear rest position and a physical memory which urges it to return to said linear rest position after being flexed, such that a passage large enough to admit a hand therethrough into the container is provided by flexing the splint and separating the sheets, an upper edge of the splint spaced at least twice the width of the splint from the top edge of the back sheet,
• c. folding an upper section of the sheets, bounded by the top edge of the sheets on top and by the upper edge of the splint on bottom, over the splint at a first fold line coincident with the upper edge of the splint thereby forming a first fold and bringing the upper section of the sheets into apposition with the splint,
• d. folding the upper section of the sheets and a lower section of the sheets forward at a second fold line coincident with a lower edge of the splint, the lower section of the sheets bounded on top by the upper edge of the splint, thereby forming a reverse fold of the upper section of the sheets adjacent the lower edge of the splint and converse to the first fold and trapping the reverse fold between the splint and the lower section of the sheets, and
• e. attaching a fastening flap having a securing panel to the front sheet below the splint, and demountably securing the securing panel to a cooperating panel on the back sheet.