| 摘要 |
<p>In a bilaterally symmetrical zipper tooth (1n) for opening in two directions which is equipped with attachment tabs (2, 7), two tapered heads (3, 4), and two anchoring slots (5, 6) which make it possible to both open and close the zipper with the aid of either of two slides that face in opposite directions, distance (d) between tops (3a, 4a) of two tapered heads (3, 4) is greater than maximum thickness (t) of the other parts of the tooth itself, such that the heads can act as a support inside of which the tooth can turn under to action of gravity.</p> |
