Ceramic lamp having electrodes supported by crimped tubular inlead

Abstract From the Canadian patent

A high pressure alkali metal vapor lamp has an envelope of alumina ceramic having an end closure which includes an externally-protecting thin-walled metal tube. The tube serves as an inlead for an electrode and as a reservoir for excess alkalu metal. The electrode is mounted on a tungsten shank which projects into the metal tube and is locked in place by crimping the tube about the shank externally of the envelope. The crimping leaves restricted channels within the tube which allow passage of the alkali metal in vapor form but prevent its movement as a liquid.