Systems and methods for applying grid lines to a shaft and sensing movement thereof

Abstract

Methods and apparatus for precisely applying finely spaced grid lines to an existing shaft on site include, in a first embodiment, attachment of a master grid line carrier to the shaft. In preferred embodiments, the carrier is helically wrapped about the shaft or mated at a diagonal seam across the carrier. Photosensitive material is then applied to the shaft at one or more axial locations. The shaft is rotated and passage of the grid lines on the master is sensed. A light source synchronized to the detection of the master grid lines exposes the photosensitive material as the shaft is rotated to create identical sets of finely spaced grid lines at multiple axial locations on the shaft. The invention also includes a synchronous laser Dopper velocimeter (SLDV) which accurately senses the passage of the lines on the shaft. An extremely accurate torsional interferometer can be constructed using the SLDVs.

Dependencies are inferred from the claim text.