Patent ID: 6453568
Filing Date: 2002-09-24
Classification: G01C,Y10S

Abstract:
A protractor comprising a body and an arm rotatably affixed to the body,a first laser affixed to the body and capable of producing a coherent light beam in a specified direction forming a first axis relative to the body, a second laser affixed to the body and capable of producing a coherent light beam in a specified direction forming a second axis relative to the body, wherein the specified direction of the first laser and the specified direction of the second laser, each extended behind the first laser and the second laser, respectively, intersect perpendicularly, and said arm rotatable about a third axis, said third axis passing through the perpendicular intersect and perpendicular to both the specified direction of the first laser and the specified direction of the second laser, a third laser affixed to the arm and capable of producing a coherent light beam in a specified direction relative to the arm, said specified direction of the third laser as extended behind the third laser perpendicularly intersecting the third axis, and means to indicate the angular relationship of the light beam of the third laser relative to at least one of the light beams of the first and second lasers.