Abstract: A process and apparatus for drilling precision small diameter holes in fuel nozzle parts includes the process of directing a laser beam against the nozzle part at a first hole drilling station to form an undersized hole therethrough and thereafter positioning the nozzle part with the laser hole formed therethrough in alignment with a wire electrode of an electrical discharge machine and controlling the energy input to the electrode wire and advancing it with respect to the preformed laser hole so as to form a precision hole diameter and surface finish throughout the length of the laser beam formed hole as EDM particles are flushed through a flow path defined by the laser hole from one face to the opposite face of a part wall.

Abstract: A wire guide directs a wire electrode from a refeed mechanism in an electrical discharge machine EDM to a workpiece. The wire guide has a tension cap and a fixed wire guide body ceramic insert defining a precision guide slot for the electrode and wherein the tension cap is biased by a flex ring mounted on separated ends of the tension cap and body to retain them together. The biased tension cap has tapered surfaces at its exit end which produce a compound tension force on the electrode for maintaining a low friction force thereon during the life of the wire guide.

Abstract: Apparatus and a process for trimming the tip of a spark erosion electrode includes a mirror system for selectively diverting a hole drilling laser beam through a path which intersects the tip of an electrode used to finish laser holes by spark erosion of the walls of the laser formed hole. The apparatus includes one mirror unit which is selectively positioned to intercept the hole drilling laser beam for diverting it for electrode trimming.

Abstract: A wire guide directs a wire electrode from a refeed mechanism in an electrical discharge machine EDM to a workpiece. The wire guide has ceramic inserts defining a precision guide slot for the electrode and wherein one of the inserts is carried by a deflectable member spring biased to damp the electrode so as to maintain concentricity of holes formed by the electrode and thereby closely control the hole diameter.

Abstract: A nozzle apparatus for focusing a beam of collimated radiation from a laser source has a spring mounted nozzle which contains the focusing lens or mirror system for establishing the actual size of the focal spot of the beam on a workpiece. Engagement of the tip of the nozzle with the workpiece or other obstacles will cause the nozzle to tilt away from the obstacle and means are responsive to such tilting movement to stop machine operation in order to clear the obstacle from the programmed path of operation of the spring mounted nozzle. Furthermore, means are provided to cause the entire assembly to be deflected upwardly when encountering an obstacle that is located in a centered relationship below the nozzle tip. The spring mounted nozzle repositions itself when it is free of the obstacle.