Circuit interrupting device
A vacuum interrupter ( 1 ) includes a tubular insulating case ( 3, 4 ) extending along a longitudinal axis (AA), two conducting caps ( 51, 52 ) each securely fixed at an open end of the tubular insulating case ( 3, 4 ) at a sealing area ( 7 ) to form a tightly sealed chamber ( 2 ). The vacuum interrupter is characterized in that the tubular insulating case ( 3, 4 ) is shaped so as to enclose the conducting caps ( 51, 52 ) and extend beyond the caps ( 51, 52 ) along its longitudinal axis (AA).
1. A vacuum interrupter ( 1 ) comprising:
a tubular insulating case ( 3 ′, 4 ′) extending along a longitudinal axis (AA); and
two conducting caps ( 51 , 52 ) each securely fixed at an open end of the tubular insulating case ( 3 ′, 4 ′) at a sealing area ( 7 ) to form a tightly sealed chamber ( 2 ),
wherein the tubular insulating case ( 3 ′, 4 ′) comprises two extension portions ( 31 , 41 ) made of insulating material and each essentially extending from the sealing area ( 7 ) along the longitudinal axis (AA) beyond a corresponding one of the two conductive caps ( 51 , 52 ) to wholly enclose and surround said corresponding conductive cap ( 51 , 52 ),
wherein the extension portions ( 31 , 41 ) are made in one piece with the tubular insulating case ( 3 ′, 4 ′), and
wherein the tubular insulating case is formed by two insulating cylinders ( 3 ′, 4 ′) which comprise each an inner flange ( 30 , 40 ) which corresponds to the sealing area ( 7 ) and on which walls ( 61 , 62 ) of the caps 51 , 52 are brazed or suitably sealed; and an angle ( 81 ) between the inner flange ( 30 , 40 ) and walls of the extension portion ( 31 , 41 ) is rounded.
2. A vacuum interrupter ( 1 ) comprising:
a tubular insulating case ( 3 , 4 ) extending along a longitudinal axis (AA); and
two conducting caps ( 51 , 52 ) each securely fixed at an open end of the tubular insulating case ( 3 , 4 ) at a sealing area ( 7 ) to form a tightly sealed chamber ( 2 ),
the tubular insulating case ( 3 , 4 ) being made of ceramic or glass-ceramic, and comprising two extension portions ( 35 , 45 ) made of ceramic or glass-ceramic,
wherein the two extension portions ( 35 , 45 ) are securely affixed to the tubular insulating case and overlap part of the tubular insulating case near the sealing area ( 7 ),
wherein the two extension portions ( 35 , 45 ) each extend essentially from the sealing area ( 7 ) along the longitudinal axis (AA) beyond a corresponding one of the conductive caps ( 51 , 52 ) to wholly enclose and surround said corresponding conductive cap ( 51 , 52 ), and
wherein the tubular insulating case is formed by two insulating cylinders ( 3 ′, 4 ′) which comprise each an inner flange ( 30 , 40 ) which corresponds to the sealing area ( 7 ) and on which walls ( 61 , 62 ) of the caps 51 , 52 are brazed or suitably sealed; and an angle ( 81 ) between the inner flange ( 30 , 40 ) and walls of the extension portion ( 31 , 41 ) is rounded.
3. The vacuum interrupter ( 1 ) according to claim 2 , wherein there is a gap ( 8 ) between the conductive caps ( 51 , 52 ) and the extension portions of the tubular insulating case.
4. The vacuum interrupter ( 1 ) according to claim 3 , wherein the gap ( 8 ) is filled with a filling resin ( 9 ).
5. The vacuum interrupter ( 1 ) according to claim 4 , wherein said filling resin ( 9 ) is either an epoxy-resin or rubber or a semi-conductive resin or ceramic- or metal-filled epoxy resin.