Axis definition apparatus
AssigneeThe Secretary of State for Industry in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorFrancis Richard Tolmon
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Abstract
There is disclosed an apparatus for defining a vertical axis by means of a reely suspended optical system acting as a plumb line. In equilibrium, the optical system has a vertical optical axis about which real images can be detected at distances of the order of a thousand feet above or below the optical system. The apparatus is capable of considerable accuracy in generating a vertical axis for alignment purposes.
Claims16
Axis definition apparatus including a laser operable to produce an output beam, focussing means for defining a point source of light from the said output beam, an optical image forming device having an optical center and being adapted to operate on light when diverging from the said point source to produce at least one real image, the said optical image forming device and point source of light defining an optical axis in terms of a line through the said optical center and point source of light, an axis control member to control the positions of the said optical center and point source of light and thereby that of the optical axis, the axis control member being freely suspended from a rotatably mounted relatively fixed member to pivot about a pivotal point whereby rotation of the relatively fixed member produces a corresponding rotation of the axis control member about a vertical axis, the said corresponding rotation producing motion of the optical axis to sweep out a conical surface characterised by a semi-angle, and means for adjusting the relative positions of the optical image forming device and the point source of light to reduce the said semi-angle to zero.
Dependencies are inferred from the claim text.