Optical transit square with focusable crossing telescopes

Abstract

A precision optical square instrument for use in optical tooling to accurately determine lines and planes at right angles to each other, such as horizontal and vertical lines and planes. The instrument employs focusable telescopes mounted at right angles to each other and supported between spaced arms of a standard rotatably mounted on a spindle connected to a base, such as for rotation about a vertical axis. The standard has opposed arms with trunnions therein supporting a first telescope for rotation about an axis, such as horizontal, for creating a first plane of view and positioned perpendicularly of the axis of rotation of the standard about the spindle. The optical axis of a second telescope perpendicularly crosses the optical axis of the first telescope at the juncture of rotative axis of the spindle with the first telescope and is rotatable orthogonally to the optical axis of the first telescope for creating a second plane of view perpendicular to the first plane. Both telescopes have focusing capability and include objective lenses, eyepiece lenses, erector lenses, adjustable focusing lenses, and reticles. Use of the instrument permits a technician to set the spindle of the standard perpendicular to any object by alignment with at least two known points by use of either or both of the telescopes in coordination. In many applications, the present instrument obviates the necessity for a second optical tooling instrument and operator.