Patent ID: 7950314

Claim:
A method of cutting sheet members, comprising the steps of: a) stacking a plurality of sheet members having air impermeability for cutting out a pattern piece from each of the sheet members; b) fixing the stack of sheet members by vacuum suction; c) welding the sheet members together vertically to fix upper and lower sheet members with respect to one another, said welding comprising locally heating at a weld location in a region of the sheet members near a predetermined cutting line of each pattern piece by frictional heat generated by contact between the sheet members and a knife or a punch of a cutting head, said welding includes piercing the stack with the knife or the punch at the weld location, moving the knife or the punch at the weld location to generate the frictional heat, and removing the knife or the punch from the stack at the weld location, wherein the region is a seam allowance of each pattern piece or a region outside the seam allowance of each pattern piece; and d) after performing step c, cutting the sheet members along the predetermined cutting line to cut out each pattern piece, wherein the predetermined cutting line extends along each pattern piece.