The utility model is characterized in that an elliptic auxiliary part for drawing ellipses is connected to the compasses on the basis of the original compasses.
其特点是在原有圆规上又连接有一个画椭圆的椭圆辅件。
Said diameter plate composed of two pieces is installed in the slot on inner side of compasses' disk. The slide valve and turning handle are on the diameter plate for drawing circle precisely.
圆规盘内侧壁设计了直径片转动槽,直径片分两片组装进入转动槽,直径片上设计有滑动阀与转动柄,从而达到精确划圆的目的。
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