Method and apparatus for position orientation of a metal halide lamp base assembly

A method for position orienting a base assembly with respect to a curved arc tube of a high intensity discharge lamp, said base assembly including a base shell having an eyelet and a locator structure attached thereto, said method comprising the steps of:

• providing within said discharge lamp an arc tube support structure coplanar with said arc tube;
• providing means for welding said locator structure to said base shell, said welding means capable of separately receiving and supporting each of said lamp and said locator structure;
• disposing said locator within said welding means and positioning said lamp within said welding means such that said base shell and said locator are in operative contact before welding;
• providing a light source proximate to said welding means and aligning the light beam of said light source perpendicular to both the longitudinal axis of said lamp and to the plane formed by said arc tube and said locator structure;
• providing a screen opposite said lamp such that a shadow image of said arc tube support structure is formed thereon when the light beam passes through the center of the neck of said lamp and impinges on said screen;
• rotating said lamp radially within said welding means until the plane formed by said arc tube and said support structure is perpendicular to said arc tube-locator plane;
• and
• activating said welding means to weld said locator structure to said base shell, thereby forming a base assembly that is position oriented with respect to said arc tube.