US 4,900,985 AGranted

High-voltage input terminal structure of a magnetron for a microwave oven

AssigneeKabushiki Kaisha Toshiba

InventorsNorio Tashiro, Masaki Adachi, Toshio Ikeda, Hisao Saito, Saburo Matsushita, Masataka Komine

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Abstract

In a magnetron for microwave oven, a high-voltage input terminal structure 30 is provided on a shield box 26 mounted on a magnetron unit 22. The high-voltage input terminal structure 30 has a cylindrical earth electrode 33, a cylindrical high potential inner electrode 32 and a central conductor 31a. The cylindrical earth electrode 33 is secured to the shield box 26 and the cylindrical high potential inner electrode 32 is coaxially arranged in the cylindrical earth electrode 33. The central conductor 31a is connected through an inductor 28 to a cathode lead 27 of the magnetron unit 22. An insulating resin 34b is filled in a gap between the cylindrical earth electrode 33 and the highpotential electrode 32 to form a capacitor section C. Cylindrical insulating sheaths 37, 38 are formed by the resin on the both sides of the capacitor section C. The capacitor section C and the cylindrical insulating sheaths, 37, 38 are integrally formed and continuously extended along a straight line.

Claims18

Dependent claims

A high-voltage input terminal structure of a magnetron for a microwave oven, said magnetron including a magnetron body having a cathode lead terminal for supplying power to the magnetron body and a shield box enclosing the cathode lead terminal, comprising:

a cylindrical earth electrode having one end secured to the shield box;
a cylindrical high potential inner electrode having a cover section provided with an insertion bore and coaxially arranged in said cylindrical earth electrode with a gap therebetween;
a central conductor fitted in the insertion bore, electrically connected to the inner electrode, longitudinally extending in said cylindrical high-potential electrode and having one end and the other end as an external terminal;
an inductor connected between the cathode lead terminal and one end of the central conductor;
an insulating resin layer for defining a capacitor portion, which is formed by a resin filled in the gap, in one direction vectorially so as to prevent the occurrence of cracks and voids, between the cylindrical earth electrode and the high-potential electrode;
and
cylindrical insulating sheaths formed with the insulating resin layer by the resin, extending from both sides of the insulating resin layer, covering a part of the cylindrical earth electrode and having a cup section in which a part of the central conductor is located to electrically insulate the central electrode from the cylindrical earth electrode, the insulating resin layer and the cylindrical insulating sheaths being continuously formed and substantially extending along a straight line.

4 more elements

Dependencies are inferred from the claim text.