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. 22, 1983
Filed:
Feb. 27, 1981
Paul E Faville, Renton, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
In a method and apparatus for determining runout in a cylindrical object, particularly a cutting or boring tool such as a drill bit or reamer, the object is rotated and a collimated beam of light is directed transversely at the rotating object so as to cast a shadow on a photosensor which produces an electrical signal having a current level representative of the area illuminated. Runout in the cylindrical object is manifested as a reciprocal variation in the area of the shadow cast on the photosensor, with a resulting periodic variation in the the output signal of the photosensor. The amplitude of this variation is determined to provide a measure of the total indicated runout of the object. In the preferred embodiment, a pair of photocells is positioned behind the rotating object and a differential amplifier and low-pass electronic filter are employed in series to separate variable signal components arising from runout from variable signal components due to profile variations in the object, for example, flutes in a twist drill.