Circle drawing and measuring device

A drafting and measuring compass for the drafting and measuring of circles, which comprises:

• (a) a template adapted to be disposed on a sheet of paper in parallel relationship to said paper and adjacent thereto,
• (b) means associated with said template to enable the same to be rotated about a predetermined center which is fixed relative to said sheet of paper,
• (c) a multiplicity of holes provided in said template and each adapted to receive a drafting instrument which will make a line on said paper in response to rotation of said template about said predetermined center so that a circle is drawn on said paper,
• said holes lying along an Archimedes spiral centered at said predetermined center,
• all holes located a first predetermined fraction of each whole number of the particular distance scale employed on said template being disposed along one radial line extending from said center,
• all the holes located a second and next-higher predetermined fraction of each whole number of the particular distance scale employed on said template being disposed along a radial line extending from said center and adjacent said one radial line, all of the holes located numerous additional fractions lying generally along additional radial lines from said center, and
• (d) indicating means on said template to indicate the particular one of said fractions which each of said radial lines represents.

A drafting compass for drafting of circles, in either pencil or ink, which comprises:

• (a) a template adapted to be disposed on a sheet of paper in parallel relationship to said paper and adjacent thereto,
• (b) point means provided on said template and adapted to be inserted into said paper to provide a center point,
• (c) low-friction protuberances provided on the lower side of said template and adapted to slide along said paper in low-friction manner to thereby achieve the conjoint benefits of reducing friction during rotation, and maintaining said template spaced from said paper whereby to prevent smearing of ink,
• (d) a multiplicity of holes provided in said template and each adapted to receive a drafting instrument which will make a line on said paper in response to rotation of said template about said point means, so that a circle is drawn on said paper, said holes being so located that those representing different fractions of whole numbers are in different sectors of a circle centered at said point means, and
• (e) indicia indicating which fraction each sector represents.

A drafting and measuring compass device with which the user can, without using a ruler, (a) first rapidly select the precise circle he desires to draw or measure and (b) then quickly and easily draw or measure said circle, said compass comprising:

• (a) a template adapted to be disposed on a sheet of paper in parallel relationship to said paper and adjacent thereto,
• (b) centering means associated with said template to enable the same to be rotated about a predetermined center which is fixed relative to said paper,
• (c) a multiplicity of holes provided in said template and each adapted to receive a drafting instrument which will make a line on said paper in response to rotation of said template about said predetermined center so that a circle is drawn on said paper,
• a first plurality of said holes each representing a first predetermined fraction of a whole number on the particular distance scale being used on said compass,
• said holes in said first plurality being so spaced, at different distances from said predetermined center, that one such hole will draw a circle the size of which is a whole number plus said first fraction on said particular distance scale;
• that a second such hole will draw a circle the size of which is a different whole number plus said first fraction on said scale;
• and so forth,
• a second plurality of said holes each representing a second predetermined fraction of a whole number on said scale,
• said holes in said second plurality being so spaced, at different distances from said predetermined center, that one such hole will draw a circle the size of which is a whole number plus said second fraction on said particular distance scale;
• that a second such hole will draw a circle the size of which is a different whole number plus said second fraction on said scale;
• and so forth,
• third, fourth, fifth, sixth and additional pluralities of said holes being similarly spaced and related as set forth above in this clause and representing, respectively, third, fourth, fifth, sixth and additional predetermined fractions of a whole number on said scale,
• all of said holes in said first plurality being so located in predetermined relationship to each other that the eye of the user will immediately and easily recognize that all such holes represent the same predetermined fraction of a whole number on said scale;
• all of said holes in said second plurality being so located in predetermined relationship to each other that the eye of the user will immediately and easily recognize that all such holes represent the same predetermined fraction of a whole number of said scale, all of said holes in said third, fourth, fifth, sixth and additional pluralities being so located in predetermined relationship to each other that the eye of the user will immediately and easily recognize that all such holes in each such plurality represent the same predetermined fraction of a whole number on said scale, and
• (d) indicia provided on said template to indicate quickly and easily to the user the particular fractions which, respectively, said first, second, third, fourth, fifth, sixth and additional pluralities represent.