Spirit level

摘要

PCT No. PCT/GB88/00269 Sec. 371 Date Nov. 28, 1989 Sec. 102(e) Date Nov. 28, 1989 PCT Filed Apr. 7, 1988 PCT Pub. No. WO88/08115 PCT Pub. Date Oct. 20, 1988.The spirit level, for use by carpenters, bricklayers or the like has a body comprising an elongate extrusion with at least one flat supporting edge 3. An outer rotatable member 10 is rotatably mounted in a transverse circular aperture in the elongate extrusion, and an inner rotatable member 11 is rotatably mounted in a transverse circular aperture in the outer rotatable member and coaxial therewith. A bubble tube 14 is secured to the inner rotatable member in fixed orientation relative thereto, such that rotation of the inner rotatable member effects coarse rotation of the bubble tube and rotation of the outer rotatable member (together with the inner rotatable member) effects fine rotation of the bubble tube. The angle can be measured by placing edge 3 on a test surface, successively rotating inner member 11 and outer member 10, and reading off the resulting angles on coarse scale 19 and fine scale 24.