| 摘要 |
A circular plate used in a time setting device has a through-hole, a plurality of arched protrusions extending downward from the bottom of the same and a pair of arched projections extending upward from the periphery of the through-hole. Each arched protrusion has a first edge spaced parallelly apart from the bottom of the circular plate and a pair of second edges which converge to the free ends of the first edge.
|
