Patent ID: 6219926
Filing Date: 2001-04-24
Classification: G01B,G01C

Abstract:
A ruler for measuring and marking lengths and angles relative to a horizontal plane by utilizing gravity, said ruler comprising:a) a substrate for being oriented relative to a horizontal plane and for measuring and marking lengths; said substrate being generally rectangular-shaped, elongated, thin, and flat with a pair of parallel edges being beveled for easy marking of measurements read from incremental length markings extending along at least one edge of said pair of parallel edges of said substrate, on its front surface; andb) an angle measuring assembly associated with said substrate for measuring and marking angles; said angle measuring assembly comprising:i) said front surface of said substrate having a longitudinal axis and at least one point along said longitudinal axis thereof, a boss with a bore axially therein;ii) said front surface of said substrate having a circumferential shoulder extending concentrically and completely around said boss on said front surface of said substrate; andiii) a cap being transparent and detachably engaging in said circumferential shoulder on said front surface of said substrate and in said bore in said boss on said front surface of said substrate; said cap of said angle measuring assembly being cup-shaped with a circumferential perimeter detachably engaging in said circumferential shoulder on said front surface of said substrate, with its concave surface facing said front surface of said substrate; said cap of said angle measuring assembly further having a post extending axially from said concave surface of said cap of said angle measuring assembly, at its center, to detachably engaging in, said bore and in said boss on said front surface of said substrate, which together with said circumferential perimeter detachably engaging in said circumferential shoulder on said front surface of said substrate allowing said cap of said angle measuring assemble to be detached from said substrate; said post of said cap of said angle measuring assembly being integral with said concave surface of said cap of said angle measuring assembly and being plastic which forms a natural bearing surface.