Patent ID: 6963284
Filing Date: 2005-11-08
Classification: G01C

Abstract:
1. A level apparatus for indicating the orientation relative to vertical of a surface of an object extending along a user line of sight, comprising: a fluid vessel containing an indicator fluid including a liquid and having a fluid surface, said fluid vessel having a vessel abutment region with a rearward abutment wall for placing against a surface of an object to be evaluated for tilt and with a forward display wall including a fluid display window extending generally perpendicular to the user line of sight, the fluid surface being visible in the fluid display window when said abutment wall is substantially upright, and includes a vessel reservoir region extending at least one of: rearwardly and forwardly from the vessel abutment region along the user line of sight, said vessel abutment region and said vessel reservoir region being in mutual fluid communication such that said fluid surface extends across said fluid display window and from said fluid display window into said vessel reservoir region and such that said fluid in said vessel reservoir region flows into and out of said vessel abutment region depending on the tilt of said apparatus along the user line of sight and thereby alters the elevation of the fluid surface in said fluid display window; wherein said reservoir region contains a sufficient quantity of said fluid that substantial tilting of said abutment wall in one of a forward direction and a rearward direction creates a readily apparent change in the position of the fluid surface visible in said fluid display window to make the tilt of said apparatus and of the surface of the object noticeable to the user.