Patent ID: 6594913
Filing Date: 2003-07-22
Classification: G01B

Abstract:
A protractor comprising:a body, said body having at least one reference surface, said body having a first measuring point thereon, a pivot on said body, said first measuring point on said body being a straight surface which is radial to said pivot pin; a dial, said dial being rotatably mounted on said pivot, a second measuring point on said dial, a reference surface on said dial, indicia between said dial and said body to indicate the angular position of said reference surface on said dial with respect to said reference surface on said body; said first and second measuring points being positioned so that said first and second measuring points move with respect to each other as said dial is rotated with respect to said protractor body and so that the ratio of the distance between said first measuring surface on said body and said second measuring point on said dial divided by the distance between said second measuring point on said dial and said pivot pin is the sine of the angle of said reference surface on said dial to said reference surface on said body.