Robert L Springer

US Patent:

49689169, Nov 6, 1990

Filed:

Sep 8, 1989

Appl. No.:

7/404805

Inventors:

John M. Davenport - Lyndhurst OH
Rocco T. Giordano - Garfield Heights OH
Richard L. Hansler - Pepper Pike OH
Robert H. Springer - Solon OH

Assignee:

General Electric Company - Schenectady NY

International Classification:

H01J 1720
H01J 1704
H01J 61073
H01J 6140

US Classification:

313571

Abstract:

A xenon metal halide lamp having an improved electrode structure that is particularly suited for automotive applications is disclosed. The electrode is comprises of a tip portion that is located at one end of a shank with the shank having a filament coiled therearound. The tip and shank portions are designed to allow for high initial current during starting and low current during operation. The coil filament is situated in opposite neck portions of an envelope forming the light source so as to; (1) cause the electrodes to be axially aligned within the light source; (2) keep the shank of the electrode from intimate contact with the envelope thereby preventing the condensation of the mercury and allowing for substantial vaporization of the metal halide ingredients at the neck portion; and (3) prevent the thermal expansion of the electrode from cracking the envelope.