Vacuum interrupter

Claim 1

A vacuum interrupter (VI) having an evacuated vacuum vessel comprising: (a) an insulating envelope (12; 25; 32) made of ceramics or crystallized glass having a metallized layer (12a; 25c; 32a) at each end portion thereof; (b) a first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 39; 40) at the periphery of which one metallized layer of said insulating envelope is brazed so as to form a hermetic seal; (c) a second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41) at the periphery of which the other metallized layer of said insulating envelope is brazed so as to form a hermetic seal; (d) a stationary electrode holder (15; 24; 39a) made of copper fixedly and hermetically extending through said first metallic end plate and having a stationary electrode contact (18) brazed to the inner end thereof; (e) a movable electrode holder (16) made of copper extending through said second metallic end plate so as to be able to move in a given direction and having a movable electrode contact (19) brazed to the inner end thereof, said movable electrode contact being in contact with said stationary electrode contact when the vacuum interrupter is closed and separated therefrom when the vacuum interrupter is open; (f) an arc shielding member (20) located within said insulating envelope so as to surround said stationary and movable electrode contacts, and brazed to said second metallic end plate at one end thereof; and (g) a metallic bellows (17) located within said arc shielding member, hermetically brazed to said movable electrode holder at one end thereof and hermetically brazed to said second metallic end plate at the other end thereof; characterised in that said first and second metallic end plates (13, 14; 22, 23; 26,27; 28, 29; 30,31; 33, 34; 35, 36; 37, 38; 38, 39; 40,41) are made of copper which has a thermal expansion coefficient different from and considerably larger than that of the ceramics or crystallized glass of said insulating envelope (12; 25; 32) and that each hermetic fixing and seal between said insulating envelope (12; 25; 32) and said first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 38,39; 40, 41 ) was obtained by plastically deforming both brazing portions of said first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30,31; 33,34; 35, 36; 37, 38; 38,39; 40, 41 ) during a temperature decrease after said first and second end plates (13, 14;.22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 38, 39; 40, 41) were brazed to said insulating envelope (12; 25; 32).

Claim 16

A method of manufacturing a vacuum interrupter (VI), comprising the step of brazing one end of a metallic bellows (17) made of an iron and chromium alloy (such as stainless steel) to a movable electrode holder (16) made of copper, the other end of said metallic bellows (17) to a second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41), an inner extended end of said movable electrode holder to one end of a movable electrode contact (19), one end of an arc shielding member (20) made of an iron and chromium alloy (such as stainless steel) to said second metallic end plate, an inner extended end of a stationary electrode holder (15; 24) made of copper to a stationary electrode contact (18), a peripheral end of a first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 39; 40) made of the same material as said second metallic end plate to a metallized layer (12a; 25c; 32a) provided at one end of an insulating envelope (12; 25; 32) made of ceramics or crystallized glass, a central hole (13c; 22a; 26a; 28a; 30a; 33a; 35a; 37a; 40a) of said first metallic end plate to said stationary electrode holder (15; 24), and a peripheral end of said second metallic end plate to another metallized layer (12a; 25b; 32a) provided at the other end of said insulating envelope uniformly once at a temperature ranging from 900°C to 1050°C under a vacuum pressure, characterised in that the first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 38, 39; 40,41) are made of copper and that the brazing temperature range is from 900°C to 1050°C and the vacuum pressure is below 10- 4 Torr.

Claim 17

A method of manufacturing a vacuum interrupter (VI), comprising the step of brazing one end of a metallic bellows (17) made of an iron and chromium alloy (such as stainless steel) to a movable electrode holder (16) made of copper, the other end of said metallic bellows (17) to a second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41), an inner extended end of said movable electrode holder to one end of a movable electrode contact (19), one end of an arc shielding member (20) made of an iron and chromium alloy (such as stainless steel) to said second metallic end plate, an inner extended end of a stationary electrode holder (15; 24) made of copper to a stationary electrode contact (18), a peripheral end of a first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 39; 40) made of the same material as said second metallic end plate to a metallized layer (12a; 25c; 32a) provided at one end of an insulating envelope (12; 25; 32) made of ceramics or crystallized glass, a central hole (13c; 22a; 26a; 28a; 30a; 33a; 35a; 37a; 40a) of said first metallic end plate to said stationary electrode holder (15; 24), and a peripheral end of said second metallic end plate to another metallized layer (12a; 25b; 32a) provided at the other end of said insulating envelope uniformly once at a temperature ranging from 900°C to 1050°C under a vacuum pressure, characterised in that the first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 38, 39; 40,41) are made of copper and that the brazing temperature range is from 900°C to 1050°C and the vacuum pressure is below 10- 4 Torr.

Claim 18

A method of manufacturing a vacuum interrupter, comprising the steps of (a) brazing one end of a metallic bellows (17) made of an iron and chromium alloy (such as stainless steel) to a movable electrode holder (16) made of copper, the other end of said metallic bellows (17) to a second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41), and one end of an arc shielding member (20) made of an iron and chromium alloy (such as stainless steel) to said second metallic end plate at a temperature ranging from 900°C to 1050°C; and (b) brazing an extended end of said movable electrode holder (16) to one end of a movable electrode contact (19), an extended end of a stationary electrode holder (15; 24) made of copper to a stationary electrode contact (18), a peripheral end of a first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 40) to a metallized layer (12a; 25a; 32a) provided at one end of an insulating envelope (15; 25; 32) made of ceramics or crystallized glass, a central hole (13c; 22a; 26a; 28a; 30a; 33a; 35a; 37a; 40a) of said first metallic end plate to said stationary electrode holder (15; 24), and a peripheral end of said second metallic end plate to another metallized layer (12a; 25b; 32) provided at the other end of said insulating envelope; characterised in that the bellows (17) are brazed to the movable electrode holder (16) and to the second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41) and the arc shielding member (20) is brazed to the second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41) at a temperature ranging from 900°C to 1050°C under a vacuum pressure below 10- 4 Torr or in a hydrogen atmosphere; the movable electrode contacts (18 and 19) are made of any one of a copper alloy, a silver alloy and a beryllium alloy, and the first and second metallic end plates (13, 14; 22, 23; 36, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 40, 41) are made of copper; and each electrode contact (18 and 19) is brazed to the respective electrode holder (15; 16; 24), the peripheral end of each of the first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 40, 41) is brazed to the respective end of the insulating envelope (15; 25; 32), and the first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 40) is brazed to the stationary electrode holder (15; 24) uniformly at a temperature ranging from 600°C to 900°C under a vacuum pressure below 10- 4 Torr.

Claim 19

A method of manufacturing a vacuum interrupter, comprising the steps of (a) brazing one end of a metallic bellows (17) made of an iron and chromium alloy (such as stainless steel) to a movable electrode holder (16) made of copper, the other end of said metallic bellows (17) to a second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41), and one end of an arc shielding member (20) made of an iron and chromium alloy (such as stainless steel) to said second metallic end plate at a temperature ranging from 900°C to 1050°C; and (b) brazing an extended end of said movable electrode holder (16) to one end of a movable electrode contact (19), an extended end of a stationary electrode holder (15; 24) made of copper to a stationary electrode contact (18), a peripheral end of a first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 40) to a metallized layer (12a; 25a; 32a) provided at one end of an insulating envelope (15; 25; 32) made of ceramics or crystallized glass, a central hole (13c; 22a; 26a; 28a; 30a; 33a; 35a; 37a; 40a) of said first metallic end plate to said stationary electrode holder (15; 24), and a peripheral end of said second metallic end plate to another metallized layer (12a; 25b; 32) provided at the other end of said insulating envelope; characterised in that the bellows (17) are brazed to the movable electrode holder (16) and to the second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41) and the arc shielding member (20) is brazed to the second metallic end plate (14; 23; 27; 29; 31; 34; 36; 38; 41) at a temperature ranging from 900°C to 1050°C under a vacuum pressure below 10- 4 Torr or in a hydrogen atmosphere; the movable electrode contacts (18 and 19) are made of any one of a copper alloy, a silver alloy and a beryllium alloy, and the first and second metallic end plates (13, 14; 22, 23; 36, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 40, 41) are made of copper; and each electrode contact (18 and 19) is brazed to the respective electrode holder (15; 16; 24), the peripheral end of each of the first and second metallic end plates (13, 14; 22, 23; 26, 27; 28, 29; 30, 31; 33, 34; 35, 36; 37, 38; 40, 41) is brazed to the respective end of the insulating envelope (15; 25; 32), and the first metallic end plate (13; 22; 26; 28; 30; 33; 35; 37; 40) is brazed to the stationary electrode holder (15; 24) uniformly at a temperature ranging from 600°C to 900°C under a vacuum pressure below 10- 4 Torr.