Abstract: A high pressure metal halide discharge lamp having a containment sleeve closed by a pair of metallic end caps for containing arc tube fragments in the event of explosive failure of the arc tube. Insulators secured in the end caps electrically insulate the arc tube lead-throughs from the end caps. Metallic tubes fixed on the lead-throughs butt against the insulators to secure the arc tube between the end caps and hold the end caps against the containment sleeve. Photoelectric emission from the end caps is avoided by electrically isolating the end caps or by providing a dielectric coating on end cap surfaces exposed to ultraviolet radiation.

Abstract: A high pressure discharge lamp having a partially collapsible frame for holding an arc tube at a predetermined angle to the lamp axis and being insertable through the neck portion of a standard bulged tube outer envelope. The frame has a first frame section welded to a standard stem assembly, a second frame section rotatably joined to the first frame section for holding the arc tube, and a third frame section rotatably joined to the second frame section for engaging the outer envelope opposite the lamp cap. The frame sections are joined by rotary locking joints and are aligned such that they pivot during insertion of the frame sections when the third frame section engages the dome portion of the outer envelope. The rotary locking joints lock with the arc tube at the desired angle.