Laser beam stop sensor for automatically detecting the presence of laser beam stop material

Abstract

A method for safeguarding regions of an airfoil adjacent to a work area from collateral damage as a result of laser operations. The method utilizes apparatus that includes a sensor assembly. The sensor assembly is fixedly attached to the laser nozzle assembly and moves with the laser nozzle assembly. The laser operations are controlled by a preprogrammed CNC controller. A fixture is used to position the workpiece in relationship to the nozzle on a laser table, the table movable in response to instructions from the controller. A beam stop material is placed over the regions of the airfoil adjacent to the work area to prevent back wall burn or to absorb reflected laser beam energy and to protect the region from other collateral damage such as stray material. The beam stop material is held in place on the workpiece and the workpiece is held in position on the fixture by elastomeric bands. On activation of the CNC program to perform the sequence of operations to accomplish preselected tasks, the laser nozzle performs as one of the operations in the sequence of operations an initial movement. The initial movement of the laser nozzle also causes movement of the sensor assembly. The sensor assembly detects the presence or absence of the elastomeric straps during the initial movement. If the elastomeric straps are detected, a signal is generated and sent to the controller, which then executes the remaining operations in the sequence of operations. If no signal is received by the controller, then the controller does not permit the sequence of operations to continue.

Dependencies are inferred from the claim text.