Folding machine and method of pressing a fold

Claim 1

A folding machine for pressing a fold along a predetermined straight line into a sheet material, comprising a machine frame, supporting means in said frame for forming a supporting surface for said sheet material, conveying means for conveying said sheet material to a predetermined position on said supporting surface, at least a first pressure jaw, and a second pressure jaw both being arranged beneath said supporting surface movable relative to each other and each having a first and a second surface and arranged so that, when said pressure jaws are separated from each other, said first surfaces define a pressure slot extending along both sides of said straight line and adapted to receive a loop of said sheet material, said second surfaces of said pressure jaws forming parts of said supporting surface adjacent to said pressure slot, means mounting at least the first pressure jaw for reciprocating movements parallel to said supporting surface relative to the second pressure jaw between an open position and a closed position of said jaws and for thereby closing and opening said pressure slot, means for influencing the formation of said loop so that said loop will be formed within said pressure slot, holding means for holding said sheet material tightly on said second surfaces of said pressure jaws so that when at least the first pressure jaw moves from its open position to a position near its closed position, driving means for actuating all of said movable means including said conveying means, said holding means, and at least said first pressure jaw and for thereafter returning the same to their original positions, so that when said sheet material is placed by said conveying means in said predetermined position on said supporting surface, it will be held by said holding means tightly on said second surfaces of said pressure jaws, whereupon said pressure slot is closed by the closing movement of at least said first pressure jaw and the loop formed during said closing movement in said pressure slot is compressed to form the fold, whereupon by the movement of said pressure jaw from its closed position to an at least partly open position, the sheet material in folded condition is released by said holding means from said jaws to permit it to be removed from said machine, gripping means, means for mounting said gripping means so as to be movable back and forth between a first position, in which they are located outside of said pressure slot and beneath said second surfaces of said jaws, and a gripping position in which said gripping means are moved into said pressure slot, and means for operatively connecting said gripping means to said driving means so that, when said pressure slot is at least partly opened after said sheet material has been folded between said first surfaces of said pressure jaws, said gripping means after said sheet material has been released by said holding means withdrawing said folded sheet material through said slot.

Claim 8

A method of producing a folded sheet material, comprising the steps of placing said sheet material in a predetermined position upon a supporting surface of a pair of pressure jaws, holding said sheet material in tight engagement with a pair of holding means on the surface of said jaws forming a part of said supporting surface, said pressure jaws in an open position being separated by a pressure slot, maintaining the pressure jaws in a fixed open position and while the jaws are stationary, lowering a folding plate against the sheet material generally centrally of the span thereof extending across the pressure slot, moving said pressure jaws from said open position toward each other when said folding plate is lowered towards said sheet material, and only after the folding plate has been raised out of the gap completing the movement of said pressure jaws from said open position toward each other to close said pressure slot and thereby forming a loop in said material by pressing said pressure jaws against each other so as to close said pressure slot and compress said loop into a fold, opening the pressure jaws following the compressing of the loop into a fold, thereafter engaging the fold by gripping means inserted between the open pressure jaws from below, and lowering the gripping means and the folded sheet material to remove the sheet material from between the pressure jaws.

Claim 9

A method of producing a folded sheet material, comprising the steps of placing said sheet material in a predetermined position upon a supporting surface of a pair of pressure jaws, holding said sheet material in tight engagement with a pair of holding means on the surface of said jaws forming a part of said supporting surface, said pressure jaws in an open position being separated by a pressure slot, maintaining the pressure jaws in a fixed open position and while the jaws are stationary, lowering a folding plate against the sheet material generally centrally of the span thereof extending across the pressure slot, moving said pressure jaws from said open position toward each other when said folding plate is lowered towards said sheet material, and only after the folding plate has been raised out of the gap completing the movement of said pressure jaws from said open position toward each other to close said pressure slot and thereby forming a loop in said material by pressing said pressure jaws against each other so as to close said pressure slot and compress said loop into a fold, opening the pressure jaws following the compressing of the loop into a fold, thereafter engaging the fold by gripping means inserted between the open pressure jaws from below, and lowering the gripping means and the folded sheet material to remove the sheet material from between the pressure jaws.