Refractory composite material based on Al.sub.2O.sub.3 in the form of corundum, SiO.sub.2 in the form of quartz and sodium aluminate having the formula NaAl.sub.11O.sub.17 or Na.sub.2O-11Al.sub.2O.sub.3, method for preparing the same, use thereof for preparing manufactured items, as well as manufactured items made thereby and use thereof.

A gas circuit breaker includes a rod-shaped fixed arc contact, a cylindrical movable arc contact to contact or be separated from the fixed arc contact, a heat puffer chamber storing an arc-extinguishing gas to be blown to an arc generated between the fixed arc contact and the movable arc contact, and an insulator received within a receiving hole formed in a distal end part of the fixed arc contact. An end surface of the insulator on a side of the movable arc contact faces the side of the movable arc contact via an opening end of the housing hole, the end surface on the side of the movable arc contact is disposed closer to the inside of the housing hole than the opening end is, and the insulator is made of an ablation material that is vaporized by heat of the arc.

A gas circuit breaker includes a rod-shaped fixed arc contact, a cylindrical movable arc contact to contact or be separated from the fixed arc contact, a heat puffer chamber storing an arc-extinguishing gas to be blown to an arc generated between the fixed arc contact and the movable arc contact, and an insulator received within a receiving hole formed in a distal end part of the fixed arc contact. An end surface of the insulator on a side of the movable arc contact faces the side of the movable arc contact via an opening end of the housing hole, the end surface on the side of the movable arc contact is disposed closer to the inside of the housing hole than the opening end is, and the insulator is made of an ablation material that is vaporized by heat of the arc.

An arc extinguishing gas filtering device for electrical current switchgear includes a porous central body including longitudinal channels and transverse channels which fluidically connect the longitudinal channels together, the longitudinal channels having a bent form; and a tight outer skin which surrounds the central body and which includes inlet orifices and outlet orifices, each longitudinal channel extending between an inlet orifice and an outlet orifice, the outer skin and the central body forming a rigid part in a single piece produced in a metallic material.

An arc extinguishing gas filtering device for electrical current switchgear includes a porous central body including longitudinal channels and transverse channels which fluidically connect the longitudinal channels together, the longitudinal channels having a bent form; and a tight outer skin which surrounds the central body and which includes inlet orifices and outlet orifices, each longitudinal channel extending between an inlet orifice and an outlet orifice, the outer skin and the central body forming a rigid part in a single piece produced in a metallic material.

An arc shield apparatus for an electrical switching device. Arc shield apparatus includes a body having an abutting portion including a first side configured to abut against a lateral side of a contact arm of an electrical switching device, and a second side opposite from the first side, an aperture passing between the first and second side, the aperture configured to receive a spring tab of the contact arm therein, and an arc shield including a first shield portion extending from the first abutting portion, the first shield portion including a first contact surface configured to abut against a contact arm edge, and a second shield portion configured to shield at least some of the spring tab and spring hook. Shielded contact arm assemblies and methods of protecting a contact arm of an electrical switching device during an arcing event, are disclosed, as are other aspects.

An arc shield apparatus for an electrical switching device. Arc shield apparatus includes a body having an abutting portion including a first side configured to abut against a lateral side of a contact arm of an electrical switching device, and a second side opposite from the first side, an aperture passing between the first and second side, the aperture configured to receive a spring tab of the contact arm therein, and an arc shield including a first shield portion extending from the first abutting portion, the first shield portion including a first contact surface configured to abut against a contact arm edge, and a second shield portion configured to shield at least some of the spring tab and spring hook. Shielded contact arm assemblies and methods of protecting a contact arm of an electrical switching device during an arcing event, are disclosed, as are other aspects.

The present disclosure describes an apparatus and method for quenching the arc developed during the interruption of a current carrying path by use of an arc quenching apparatus with a contiguous chamber that shapes and directs the gas pressure and other associated arc components through a set of splitter plates located at the ends of the chamber. The contiguous chamber contains the gas pressure and other associated arc components for the duration of the quenching process.

The present disclosure describes an apparatus and method for quenching the arc developed during the interruption of a current carrying path by use of an arc quenching apparatus with a contiguous chamber that shapes and directs the gas pressure and other associated arc components through a set of splitter plates located at the ends of the chamber. The contiguous chamber contains the gas pressure and other associated arc components for the duration of the quenching process.

A mechanical breaker apparatus for breaking an electric circuit comprises two electrodes that are movable relative to each other, and including an electric arc splitter device having a multitude of distinct conductive elements that are spaced apart and electrically insulated relative to one another. The splitter device has a first portion and a second portion that are movable relative to each other between: an electrical contact position; and a spaced-apart position of the two portions. The splitter device has at least one series of the distinct conductive elements that, in an electrically closed position of the electrodes of the mechanical apparatus, are arranged along the continuous electrically-conductive path for the nominal electric current through the apparatus as defined by the two portions of the splitter device in the electrical contact position.