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:
Jan. 21, 1992
Filed:
Feb. 25, 1991
Applicant:
Inventor:
David Stroud, Bristol, GB;
Assignee:
Rolls-Royce plc, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
21912171 ; 2191217 ; 21912184 ;
Abstract
In the laser drilling of gas turbine engine blades there is provided a method of maintaining constant the distance between a laser nozzle and the surface to be drilled by measuring the topography of the surface and using that data to control the focusing of the laser beam onto the surface. The topography is measured by determining the back pressure of a stream of oxygen blown through the nozzle onto the surface, and relating the back pressure to the distance between the nozzle and the surface. The distance measured is used to control a servo operated table so as to move the surface to the optimum distance from the nozzle.