Patent ID: 7839066

Claim:
In an arc discharge lamp having a longitudinal axis and comprising: an arc tube having a hollow body containing an arc generating and sustaining medium; electrodes extending into said hollow body, one from each end of said arc tube, said electrodes and said hollow body being arrayed along said longitudinal axis; a sealed shroud surrounding said arc tube, said shroud and said arc tube forming an arc tube assembly; a lamp envelope surrounding said arc tube assembly, said envelope including a base portion having a cylindrical part, a side wall and a top opposite said base portion; electrical lead-ins extending through said base portion and mechanically and electrically connected to said arc tube electrodes; the improvement comprising: a strengthening member for preventing said arc tube assembly from displacement from said longitudinal axis as a result of forces applied in a direction substantially normal to said axis, said strengthening member being free of contact with said top of said envelope and comprising: an elongated element having first and second ends; said first end engaging said sealed shroud of said arc tube assembly and said second end engaging said cylindrical part of said base portion of said arc lamp.