Patent ID: 7343769

Claim:
A corrugation forming method of forming streaky recesses and projections on a thin metal plate, the method comprising the steps of: providing a first pair of meshing members that mesh with each other with a predetermined clearance therebetween, the predetermined clearance being greater than the thickness of the thin metal plate; placing the thin metal plate between the first meshing members; displacing one of the first meshing members relative to the other of the first meshing members in synchronism while the thin metal plate is placed between the first meshing members to successively form streaky recesses and projections along the entire width of the thin metal plate; and removing the thin metal plate having successively formed recesses and projections, wherein the first meshing members are driven in synchronism with a displacement synchronization mechanism that includes a second pair of meshing members, wherein one of the second meshing members is fixed relative to the one of the first meshing members and the other of the second meshing members is fixed relative to the other of the first meshing members, and wherein the second meshing members mesh with each other with no allowance therebetween to accurately displace the one of the first meshing members relative to the other of the first meshing members.