Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki Kaisha

Tadaki Murakami

Kazuharu Kato

Isao Ishii

Shinji Yamagata

Hiroshi Adachi

Fumiaki Baba

Osamu Hiroi

Takao Mitsuhashi

Kazunori Fukuya

Shunichi Katsube

Kenichi Nishina

Itsuo Nishiyama

Shoji Yamaguchi

Hiroshi Takayanagi

Mitugu Takahasi

Hitoshi Yamazaki

Kazuo Okahashi

Takao Takeda

Takashi Shirazawa

Yoshikazu Utsumi

Yoshiaki Sakamoto

Tatsuharu Nakamura

Takasi Shirazawa

Yasuhiko Ikeda

Toyoshi Takeuchi

Yoshihiro Murakami

Kiyoshi Takata

A switch containing a switch case, contacts adapted to be opened and closed, an arc extinguishing chamber disposed in the vicinity of the contacts, and an arc extinguishing material capable of reducing the amount of metal particles and free carbons to be scattered from components disposed within the switch by an arc generated when the contacts are opened or closed or capable of insulating the metal particles and the free carbons to convert into an insulator, thereby inhibiting a decrease in arc resistance expected to occur upon the generation and extinction of the arc and a decrease in insulation resistance expected to occur within and around the arc extinguishing chamber and at inner wall surfaces of the switch case upon and after the extinction of the arc. The switch is applicable to a switch expected to generate an arc upon interruption of electric current flowing therethrough such as a circuit breaker, current-limiting device or electromagnetic contactor and is capable of immediately extinguishing the arc and inhibiting the decrease in insulation resistance within and around the arc extinguishing chamber and at inner wall surfaces of the switch case.

Switch and arc extinguishing material for use therein

A switch comprising a switch case, contacts adapted to be opened and closed, an arc extinguishing chamber disposed in the vicinity of the contacts, and an arc extinguishing material capable of reducing the amount of metal particles and free carbons to be scattered from components disposed within the switch by an arc generated when the contacts are opened or closed or capable of insulating the metal particles and the free carbons to convert into an insulator, thereby inhibiting a decrease in arc resistance expected to occur upon the generation and extinction of the arc and a decrease in insulation resistance expected to occur within and around the arc extinguishing chamber and at inner wall surfaces of the switch case upon and after the extinction of the arc. The switch according to the present invention is applicable to a switch expected to generate an arc upon interruption of electric current flowing therethrough such as a circuit breaker, current-limiting device or electromagnetic contactor and is capable of immediately extinguishing the arc and inhibiting the decrease in insulation resistance within and around the arc extinguishing chamber and at inner wall surfaces of the switch case.

Mica-containing ceramic composite having excellent characteristics such as capability of machining work, a small thermal expansion coefficient, high heat-shock resistant temperature difference as well as high heat deformation temperature, is prepared by: a) preparing powder mixture by blending 20 to 50% by weight of mica powder, 15 to 40% by weight of zinc oxide powder, 10 to 20% by weight of silica powder, 8 to 20% by weight of boric acid powder, and 4 to 20% by weight of cordierite powder; b) heating the powder mixture at a temperature of from 940.degree. C. to 1,050.degree. C. to prepare baked product; c) pulverizing the baked product into very fine powder to thereby obtain a shaping material; d) adding an organic binder to the shaping material to prepare a shaping composition; and e) shaping the shaping composition into a shaped body and heating a shaped body at a temperature ranging from 940.degree. C. to 1,050.degree. C. with simultaneous application of pressure to the shaped body to render the same into a baked body.

Process for preparing mica-containing ceramic composite

A method of manufacturing readily machinable high strength glass ceramics includes the steps of: preparing a powder mixture by mixing glass powders 1 and 2, each having a predetermined composition, with each other; and producing a calcined product by granulating, molding, and heating the powder mixture. This method makes it possible to obtain readily machinable high strength glass ceramics of a novel composition, which exhibit a heat resistance of not less than 1000.degree. C., which excel in mechanical strength and electrical insulation performance, and which allow precision machined parts and large-sized products to be produced with ease.

Method of manufacturing readily machinable high strength glass ceramics

A method for producing an air-tight, heat-resistant plate for a particular use in manufacturing bulbous fluorescent lamp, which comprises: preparing a shaping material by mixing an inorganic filler composed of alumina powder and silica powder in a specified compositional ratio, and glass powder having a thermal expansion coefficient of 8.5 to 11.5.times.10.sup.-6 /.degree.C., both inorganic filler and glass material being blended at a predetermined ratio then, forming the shaping material into a shaped product of any desired configuration by a known shaping method; thereafter heating this shaped body to a temperature, at which the glass powder used becomes molten and fused, thereby rendering it to be a burned body.

Method for producing air-tight, heat-resistant plate

A process for preparing a heat resistant soft composite which comprises hot-pressing a mixture comprising talc powder and mica powder as major components and a bonding material composed of normal boric acid, boric acid anhydride and zinc oxide, at a temperature of from 160.degree. to 200.degree. C. under pressure of from 50 to 100 kg/cm.sup.2 to form a composite, and subjecting the composite to heat treatment at a temperature of from 450.degree. to 500.degree. C.

Process for preparing a heat resistant soft composite

The present invention is a heat treatment jig for use in the baking process, the frit seal process, and the evacuation process during the manufacture of cathode-ray tubes. It comprises a base and one or more support members formed from a novel material comprising mica, talc, orthoboric acid, boric acid anhydride, and zinc oxide molded under heat and pressure. This novel molded material is superior in its mechanical properties to the substances (asbestos tape, asbestos cement, or boron nitride) used for the support members of conventional heat treatment jigs. In addition, it does not pose a danger to health like asbestos products and it is far lower in cost than boron nitride.

Heat treatment jig for use in the manufacture of cathode-ray tubes

An arc resistant insulator composed of a composite composition comprising an insulating base material and a zinc borate hydrate. The insulating base material is composed of aluminum oxide and/or aluminum hydroxide and mica power. The zinc borate hydrate is composed essentially of 2ZnO.3B.sub.2 O.sub.3.3H.sub.2 O. The arc resistant insulator is prepared by mixing the insulating base material with a zinc borate hydrate forming material composed of normal boric acid, boric acid anhydride and zinc oxide and heating and compacting the mixture thus obtained in a closed system at a temperature of at least 155.degree. C. under pressure of at least 50 kg/cm.sup.2.

Arc resistant insulator

Growing community of inventors

Amagasaki, Japan

Tadaki Murakami