| 摘要 |
<p>DEVICE FOR CENTERLESS CIRCLE CONSTRUCTION A template set for inscribing a plurality of curvilinear figures with pencil, inking pen or other marking means is disclosed. The invention comprises a two-part unit for small circles, or a three-part unit for larger circles, enabling an individual circle or family of circles to be drawn without a compass, where such circles have a common center. The device can further be used to draw ellipses of varying size, the ellipses having varying sizes and degrees of eccentricity, and having common foci. The device consists of an exterior holder, an interior holder, a large-circle guide portionand a small-circle guide portion. In the embodiment for drawing large circles, a shim is used to maintain the large-circle guide portion in spaced relationship from the drafting medium.</p> |
