METHOD OF MANUFACTURING PLAIN ROOF TILE

PROBLEM TO BE SOLVED: To provide a method of manufacturing a plain roof tile which can be used for shortening the machining time and suppressing the occurrence of dust associated with machining when grinding a bottom side end surface for self-supportingly calcining a roof tile substrate. SOLUTION: The plain roof tile substrate 55 where a pair of right and left hook claw parts 14 projecting downward side on the bottom part end surface 12 and an engaging hook 13 projecting upward between them are formed, is molded by pressing a clay material. A projection part projecting rearward side is formed at the position of both hook claw parts 14 and the engaging hook 13 on the bottom part end surface 12. The molded plain roof tile substrate 55 is contracted in a drying process, but in the result of contraction, only the projection part is projected to the further rearward side than the reference plane to be the target of the bottom part end surface 14 of the plain roof tile substrate 55. On the plain roof tile substrate 55 obtained in these ways, the projection part is projected from the reference plane of the bottom part end surface 12. These projection parts are ground in a grinding process until it becomes approximately flush with the reference plane to form a rectangular area 18 and a hook shape area 19. COPYRIGHT: (C)2009,JPO&INPIT