| 摘要 |
<p>PURPOSE: To speedily and smoothly perform engagement action, to prohibit excessive invasion of an engagement head part of a counter part, and to hold a stable condition of engagement. CONSTITUTION: A coil fastener element 2 is formed of an engagement head part 4 swollen on both sides, upper and lower leg parts 5, 6 continuous with the engagement head part 4, and a connection part 7 connecting the upper and lower leg parts 5, 6 to each other. A step part is provided at a center of the upper leg part 5 to form the side of the engagement head part 4 thicker and the side of the connection part 7 thinner, an engagement space part 9 is provided between the upper and lower leg parts 5, 6, a protruded part 10 protruded into the engagement space part 9 is provided on the back side of the step part of the upper leg part 5, a slope part 12 where the engagement space part 9 is gradually enlarged is formed from an upper inner part of the engagement head part 4 toward a base part 11 of the protruded part 10, a core cord 28 is inserted between the upper and lower leg parts 5, 6, they are sewn to each other by means of a fixed yarn 14 and a double chain sewing yarn 15, a side edge of the core cord 28 is protruded toward the engagement head part 4, the engagement head part 4 is speedily engaged along the slope part 13 in engagement, and excessive invasion is prevented by the protruded part 10 and the core cord 28, thereby engagement is stabilized.</p> |
