| 摘要 |
PROBLEM TO BE SOLVED: To prevent the external surface of a cap main body from being damaged, and in addition, enable a sure and easy positioning in the circumferential direction regardless of the shape of the cap main body by a method wherein the shape of the cross sectional face on the internal surface of the cap main body where an uneven part which is provided for the positioning in the circumferential direction is located, is made asymmetrical with respect to a point axially. SOLUTION: A cap main body 2 is a cylindrical body having bottom, which is obtained by an injection molding of a synthetic resin, and on the external surface of the cap main body 2, a clip attaching hole 26 is made on the front side in the axial direction, and a chip 6 made of a metal is attached by insertion. From the internal surface of the top wall to the internal surface of the peripheral wall of the cap main body 2, a plurality of ribs 25 which extend in the axial direction are integrally provided with equal intervals. At an intermediate part of one of the ribs 25, a protruding part 31 of a step shape, which is thicker than other ribs 25, and greatly protrudes inwardly in the diametrical direction, is formed, and the shape of a cross sectional face of the internal surface of the cap main body 2 where the protruding part 31 is located, is made asymmetrical with respect to a point axially. At the same time, a recessed part 32 is formed around the protruding part 31, and an uneven part 3 is constituted of the protruding part 31 and the recessed part 32. |
