(under subclass 1) Method to provide the electric lamp or electric space discharge device with special features or means to safeguard against or to prevent inward collapse or bursting of an evacuated hermetically sealed vessel.
SEE OR SEARCH CLASS
313, Electric Lamp and Discharge Devices, appropriate subclasses, note especially
477+, for CRT envelopes, per se, and subclass 634 for envelopes containing gas or vapor having particular envelope structure.
314, Electric Lamp and Discharge Devices: Consumable Electrodes, appropriate subclasses.
