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:
Jun. 25, 1991
Filed:
Feb. 28, 1986
Ralph M Somers, West Chester, OH (US);
Diana R Compton, Cincinnati, OH (US);
General Electric Company, Cincinnati, OH (US);
Abstract
An apparatus and method for detecting when a hole has been drilled through a workpiece by way of a pulse laser drilling process having a machine control for controlling whether the pulse laser drill emits laser pulses. The apparatus detects the laser pulse and produces an output signal representative thereof. The output signal is clipped and compared to a first reference signal for producing a compared output signal when the clipped output signal is greater than the first reference signal. The compared output signal triggers an enabling output signal representative of a pulse having a predetermined interval. The apparatus also detects reflected radiation from an entrance of the hole being drilled to produce an output signal which is then clipped and compared to a second reference signal to produce a disabling output signal when the output signal representative of the reflected radiation is greater than the second reference signal. When the disabling signal terminates before the enabling signal a gating pulse indicative of when a hole is drilled is generated for stopping any further laser pulse.