US 4,052,576 A · Contact structure for SF.sub.6 arc spinner

Abstract

A single pressure sulfur hexafluoride circuit interrupter is contained in a bottle or elongated, cylindrical housing filled with gas under moderate pressure. The bottle contains arcing and main contacts arranged generally along the axis of the bottle and arranged to separate from one another in the vicinity of a pair of spaced, conductive rings fixed relative to one another, and which serve as arc runners. Each of the rings is connected in series with a respective coil which is wound on the axis of its respective ring and which encircles the cooperating contact and conductors therefor. The coils and the conductive rings create a magnetic field which spins an arc drawn between the spaced short-circuited rings through the sulfur hexafluoride gas, thereby to extinguish the arc. Each short-circuited ring and its respective coil are fixed relative to one another and are contained within a common insulation body in order to withstand the high electrodynamic forces created between the rings and coils during high current interruption. A small, low capacity puffer cylinder is connected to one of the moving contacts in order to produce at least a limited amount of gas motion through the arc space between the open contacts and the fixed rings when the contacts separate. The arcing contacts are arranged to have a blow-off path directed to cause an arc drawn between the contacts to transfer to the spaced conductive rings. In one embodiment of the invention, only a single coil is used to produce a magnetic field for spinning the arc between the spaced rings. The interrupter structure is useful in connection with a vacuum dielectric medium. Other embodiments of the invention show different forms of arcing contacts and different arrangements for introducing the spaced conductive rings into the circuit during interruption conditions. In another embodiment of the invention, a single conductive ring with a single coil cooperates with the movable contact. In still another embodiment of the invention, the conductive rings which form a gap within which the arc is circulated also serve as movable arcing contacts and are movable relative to one another.

Claims17

Dependent claims

A circuit interrupter comprising an elongated cylindrical housing filled with dielectric gas at a single pressure, first and second cooperable conductive rings operable to define an arcing gap between their opposing surfaces and composed of high conductivity material, and an electrical winding closely magnetically coupled to said first conductive ring;

said first conductive ring defining a short-circuited turn;
said electrical winding being operable with said first conductive ring to produce a magnetic field which is out of phase with the arc current to be interrupted by said circuit interrupter for rapidly spinning an arc around said arcing gap even near instantaneous current zero, first and second terminals fixed to said circuit interrupter;
said first terminal, said winding, said first conductive ring, said second conductive ring and said second terminal being connected in electrical series;
said first and second conductive rings and said winding being coaxial with the axis of said cylindrical housing;
first and second interrupter contacts connected to said first and second terminals respectively and relatively movable parallel to the said axis of said cylindrical housing between an open and a closed position;
said first conductive ring and said electrical winding having internal diameters;
said first and second interrupter contacts being concentrically disposed within the interior of said internal diameters of said first conductive ring and said electrical winding;
said first and second interrupter contacts engaging in a region axially aligned with said arcing gap.

5 more elements

A circuit interrupter comprising a sealed housing filled with a static dielectric gas at a single pressure greater than atmospheric pressure, a first ring of relatively high conductivity material disposed within said housing and serving as a short-circuited winding and as the first of a pair of cooperable interrupter contacts;

a second and ring-shaped interrupter contact which is coaxial with and longitudinally movable along the axis of said first ring and which is movable into and out of engagement with said first ring;
an electrical winding closely magnetically coupled to said first ring and wound about the axis of said first ring;
first and second terminals for said circuit interrupter;
said first terminal, said winding, said first ring, said second interrupter contact and said second terminal being connected in electrical series when said second interrupter contact engages said first ring;
and a pair of cooperable main contacts connected to said first and second terminals respectively and operated relative to said first and second interrupter contacts, whereby said main contacts are opened before said interrupter contacts are opened;
said electrical winding inducing a high circulating current in said first ring when current flows in said electrical winding;
said current in said electrical winding and said circulating current in said ring producing a magnetic field which passes through the arc current drawn between said first ring and said second interrupter contact and which is phase-shifted from the arc current, thereby to cause said arc current to rapidly rotate through the static dielectric gas which is between said first ring and said second interrupter contact, even at low instantaneous arc current values, whereby the relative movement between said static dielectric gas and said arc current assists in the extinction of said arc current.

4 more elements

Dependencies are inferred from the claim text.

Contact structure for SF.sub.6 arc spinner

Life of this patent

Contact structure for SF.sub.6 arc spinner

Life of this patent

Abstract

Claims17