Improvements in Implements for Drawing Circles and Curves with Definite Relation to Straight Lines or Polygonal Forms, and Tangents to Circles and Curves.

摘要

24,597. Swenson, H. A. Nov. 12. Curves, figures, &c., plotting; tangents, laying-off. -Relates to instruments for drawing circles or curves tangentially, or in definite relation to lines or polygonal forms, and for performing the reverse operation. Fig. 1 shows a drawing-curve made of wood, paper, pasteboard, celluloid, vulcanized rubber, steel, aluminium, german silver, or other material, with tangent lines a on one or both faces, perforations a1 being formed at the points of intersection. A tangent gauge may be pivoted to one end of the curve. Fig. 2 shows a modification with two sides c tangent to a curve d, perforations e being formed where this curve intersects the tangent lines a. Fig. 4 shows a set-square in which tangential curves are drawn from two corners, perforations being provided at their points of intersection. In the case of a set-square having the central part cut away, curves proceed from one corner only, and notches are provided in the edges of the square.