| 摘要 |
PROBLEM TO BE SOLVED: To provide an inner plug fixing structure for prevention of fraudulence in which the inner plug is prevented from being easily removed by shielding an outer circumferential portion becoming a hook to be engaged with the inner plug. SOLUTION: A spout 11 is formed of a middle step 11a at its distal end rather than a forming part of a threaded portion 14, an outer diameter at a distal end rather than the middle step 11a is narrowed to form a large step 11b. The inner plug 12 is provided with a fitting segment 16 of double-walled structure comprised of an inner annular piece 16a and an outer annular piece 16b protruded in a concentric manner at a rear surface circumferential edge of a closing plate 15. The inner plug 12 is fitted under a state in which the large step 11b is held by both annular pieces 16a, 16b. A shielding wall 23 brought into substantially close contacted with and enclosing an outer circumference of the outer annular piece 16b becoming a hook to be engaged with a finger is fitted to an outer part of the middle step 11a. An annular protrusion 24 and an annular notch 25 engaged to each other are formed between an inner circumference of a base end of the shielding wall 23 and an outer circumference of the middle step 11a to enable the shielding wall 23 to be removed. |
