(under subclass 121) wherein the tube includes means such as getters, regulators, and pumps to permit variation of the
vacuum within the tube or which act continuously to maintain the vacuum, e.g., by scavenging.
SEE OR SEARCH THIS CLASS, SUBCLASS:
125+, and 135, for X-ray tubes with movable electrodes which may include vacuum seals for the electrode moving means.
SEE OR SEARCH CLASS
313, Electric Lamp and Discharge Devices,
547, for related subject matter used in discharge devices generally.
445, Electric Lamp or Space Discharge Component or Device Manufacturing, 38+, and 73 for related subject matter used in the manufacture and repair of discharge devices.
