METHOD FOR MANUFACTURING CONCRETE FLOOR BOARD WITH COTTER RECESS, COTTER MOLDING MACHINE USED THEREFOR, APPARATUS FOR MANUFACTURING CONCRETE FLOOR BOARD WITH COTTER MOLDING MACHINE AS WELL AS COTTER CONCRETE BOARD MANUFACTURED BY THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a concrete floor board in which hollow holes are perforated having sufficiently large area and depth of cotter recesses, capable of easily and surely forming the cotter recesses with sufficient supporting force, no skin roughness on its surface, and having not only safety in transporting and hanging works but also smooth appearance, high commodity value. SOLUTION: The method for manufacturing the concrete floor board with the cotter recesses comprises the steps of forming two crude mortar layers C on a surface of a cotter roller 35 and the concrete floor board P in the case of molding the floor board P, pushing the roller 35 having cotter molding protrusions 36 to the layers C via a soft synthetic resin film band F.