| 摘要 |
848,589. Thermionic cathode constructions. SIEMENS EDISON SWAN Ltd. May 28, 1959 [June 10, 1958], No. 18535/58. Drawings to Specification. Class 39(1). [Also in Group XI] A cathode heater comprises a coiled heating element embraced by a sleeve of refractory electrically insulating material having an external helical protuberance, preferably of hollow form extending along it, which determins the minimum spacing of the heater from the cathode sleeve. The heater may be of hairpin or M-shaped configuration, suitable dimensions being given. |
