Patent ID: 7117608
Filing Date: 2006-10-10
Classification: G01C

Abstract:
1. A spirit level comprising: an elongate body that is rectangular in cross-section with a hollow interior and having a level face for setting a surface, a viewing face opposite said level face, and two side faces connecting said level face and said viewing face, said level face, viewing face and side faces determining an internal body area within said body and an external body area outside said body, said elongate body also having two end portions and a central portion between said end portions; a first elongate bubble vial mounted in said internal body area and having a generally longitudinal axis mounted in said central portion of said body such that said first bubble vial longitudinal axis is parallel to said level face, said first bubble vial being viewable when looking at said viewing face for determining if a setting surface is level; at least a second bubble vial mounted in said internal body area and having a generally longitudinal axis mounted in one of said end portions of said body such that said second bubble vial longitudinal axis is perpendicular to said level face, said second bubble vial being viewable when looking at, at least one of, said side faces for determining if a setting surface is plumb; and an optical transfer element fixed to said body and extending beyond said body in said external body area, said optical transfer element transferring an image of at least a central portion of said second bubble vial to a viewing plane generally parallel to said level face.