The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 07, 1989
Filed:
Aug. 10, 1987
Hinrich Heynisch, Graefelfing, DE;
Josef Hauser, Bad Wiessee, DE;
Erwin Hubner, deceased, late of Grafing, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A dispenser cathode such as a metal capillary cathode for electrical discharge devices which has a hollow cylindrical head portion 1 which carries a porous emission wafer 3 of a refractive material at its upper end and covers a cathode cartridge 2 which contains an active material supply 4 and comprises an epoxy helical heater 5 surrounded by a metal sleeve 6. Two part division of the structure allows separate testing possibility of the emission wafer and the heater/supply cartridge and also allows an improvement in the heat transmission from the heater to the emission wafer. For this purpose, a hollow cylindrical head portion 1 is conically-shaped and expands outwardly toward the cathode cartridge 2 and the upper part of the cathode cartridge 2 is conically tapered so as to mate with the hollow cylindrical head portion and the two portions are connected together wherein their conical side walls are attached by welding in the upper portion of the drawn up metal sleeve. The dispenser cathode can be used in travelling wave tubes for example.