Gte Sylvania Incorporated

Bernard Cohen

Emery G Audesse

Donald E Armstrong

Ronald E Sindlinger

John E Tozier

A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having a beadless ignition structure comprising a pair of spaced apart lead-in wires with spherically shaped terminations, a glass frit coating over the lead-in wires with scraped-off portions exposing the bare metal of the wire adjacent each termination, and a coating of primer material over the frit-coated terminations and bared portions of the wires. The primer may bridge the wire terminations or comprise separate spaced apart coatings on the respective terminations, with the filamentary combustible being in contact with both terminations to provide a conducting path therebetween. The frit coating is thick enough to prevent preignition short circuits. Also disclosed is a method of making the lamp including the steps of applying a flame to melt down the ends of the lead-in wires to provide smooth and rounded terminations, dipping the wires in a liquid suspension of glass frit, air drying, passing a blade between the wires to scrape away portions of the frit coating and expose bare wire adjacent the terminations, sealing the lead-in wires into one end of a length of glass tubing, dipping the coated lead-in wires into a primer cup to provide a coat of primer over the terminations and scraped portions, and then finishing the lamp.

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Williamsport, PA, United States of America

Bernard Cohen