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:
Oct. 31, 2000
Filed:
Jun. 18, 1998
Ralph M Somers, Cincinnati, OH (US);
John M Crow, Morrow, OH (US);
General Electric Company, Cincinnati, OH (US);
Abstract
In a pulse laser drilling process having a machine control for controlling a laser, an apparatus is provided to detect when a hole is drilled through a workpiece. The apparatus detects a laser pulse, where the laser pulse emits a laser light upon drilling impact with the workpiece. A second detection step detects sparks emitted by the workpiece, and a spark signal amplitude representative thereof is produced. The sparks produce visible wavelength light. A filter blocks the laser light and transmits the visible wavelength light. A photosensor associated with the filter senses when the spark signal amplitude diminishes below a predetermined threshold level. An output signal, responsive to the photosensor indicates when a through hole is complete and indicates to the machine control to stop any further laser pulse.