CORRUGATED HORN

PURPOSE:To simplify the structure and to facilitate the manufacture by holding plural rings having a prescribed thickness and outer diameter and having a different corrugated slot on one face laminatingly in a cylinder having the same inner diameter as the outer diameter of the rings. CONSTITUTION:A cylinder 3 having an annular projection 31 is formed to an inner wall of one end by a cut or drawing processing. Then a ring 311 having th similar shape to that of the ring is formed by utilizing the projection 31. The ring 5 has an outer diameter equal to the inner diameter of the cylinder 3, a hole 51 is provided at the center, a slot of prescribed depth is provided at the surrounding of the hole 51 of one face to provide a corrugated slot 52. Plural rings 5 are inserted in the cylinder 3 laminatingly and the diameter of each hole 51 has a difference so as to form the edge of the holes 5a connected in the laminating state as a corrugated form. Plural rings 5 are clipped between the projection 31 of the cylinder 3 and the retainer plate 4 and the retainer 4 is tightened to hold each ring 5 in the laminating state in the cylinder 3.