The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 05, 1985
Filed:
Sep. 29, 1982
Seetha R Mannava, Latham, NY (US);
John F McDonald, Clifton Park, NY (US);
Henry A Scarton, Troy, NY (US);
General Electric Co., Schenectady, NY (US);
Rensselaer Polytechnic Institute, Troy, NY (US);
Abstract
The velocity and change in velocity of a rotating or otherwise moving surface is measured by a laser Doppler technique. In particular, a diffraction grating is formed on the moving surface either by machining processes or by affixing a ready-made grating thereto. The grating surface exhibits periodicity in one or more directions, either separately or simultaneously. The presence of the grating produces Bragg order diffraction reflections at specific angles relative to the surface. These Bragg order reflections contain information, in the form of Doppler shifts, concerning the motion of the surface and the body to which it is attached. This Bragg order Doppler shift information is readily analyzable using conventional signal processing apparatus and processes to produce the desired velocity and torsional vibration information.