US 4,229,627 A · Gas puffer type current interrupter and method

Abstract

The invention provides for a gas puffer type current interrupter having a pair of separable contacts, one of which is surrounded by a nozzle formed of electrically insulating material. Upon separation, an arc is drawn between the contacts through the throat of the nozzle. The method of the invention includes permitting the arc to fill and clog the nozzle throat thereby restricting the escape of dielectric gas which is being forced into the nozzle. The clogging of the nozzle by the arc is permitted to an extent sufficient to raise the temperature within the nozzle such that significant ablation of the nozzle material occurs interior of the nozzle. The ablation or evaporation of the nozzle material produces a significant increase in pressure within the nozzle which serves to rapidly extinguish the arc. The interrupter includes a nozzle having a throat size selected so that the cross sectional area of the arc substantially fills the throat. The nozzle will be clogged a sufficient portion of the time between contact separation and arc extinction to produce the desired ablation of the nozzle material.

Claims17

Dependent claims

A method of current interruption for use in a current interrupter having a pair of relatively movable contacts including a first said contact disposed in a nozzle formed of electrically insulating material having a nozzle throat and a second said contact extending into said nozzle throat and engaging said first contact to complete a current path, said method comprising the steps of:

separating said contacts to interrupt current flow such that an arc arises between said contacts, including causing the withdrawal of said second contact from said nozzle throat whereby the arc extends through said nozzle throat substantially filling said nozzle throat, directing dielectric gas into said nozzle under pressure, clogging said nozzle throat with the arc arising between said contacts to restrict escape of said dielectric gas from said nozzle, and continuing the clogging of said nozzle throat to an extent sufficient to raise the temperature within said nozzle such that significant ablation of said nozzle material occurs within said nozzle thereby producing a significant increase in pressure within said nozzle to rapidly extinguish said arc.

A method of current interruption for use in a gas puffer type current interrupter having an enclosure filled with a dielectric gas, a pair of relatively movable contacts in said enclosure including a first said contact disposed in a nozzle formed of electrically insulating material having a nozzle throat and a second said contact extending into said nozzle throat and engaging said first contact to complete a current path, said contacts being separable to permit an arc to arise between said contacts through said nozzle throat, the cross sectional area of said arc being dependent on the current carried by said arc, and a gas compressing chamber in said enclosure communicating with said nozzle, said method comprising the steps of:

passing at least a predetermined magnitude of current through said interrupter when said contacts are engaged, said predetermined magnitude of current being sufficient to cause the arc arising upon contact separation to have a cross sectional area which substantially fills and clogs said nozzle throat, separating said contacts including causing the withdrawal of said second contact from said nozzle throat whereby an arc arises through said nozzle throat, compressing said dielectric gas in said gas compressing chamber and directing the resultant pressurized dielectric gas into said nozzle, clogging said nozzle throat with said arc to restrict escape of said dielectric gas through said nozzle throat, and continuing the clogging of said nozzle throat to an extent sufficient to raise the temperature within said nozzle such that significant ablation of said nozzle material occurs within said nozzle thereby producing a significant increase in pressure within said nozzle to rapidly extinguish said arc.

A current interrupter of the gas puffer type comprising:

a pair of relatively movable contacts, a nozzle formed of electrically insulating material surrounding a first said contact, said nozzle having a nozzle throat, a second said contact which extends into said nozzle throat when engaging said first contact, said first and second contacts being relatively movable to separate said contacts and to remove said second contact from said nozzle throat when said contacts are opened permitting an arc to arise between said contacts through said nozzle throat, and means for directing a dielectric gas into said nozzle for discharge through said nozzle throat, the size of said nozzle throat being selected so that the cross sectional area of said arc will substantially fill and clog said nozzle throat and restrict escape of said dielectric gas therefrom to an extent sufficient to raise the temperature within said nozzle such that significant ablation of said nozzle material occurs within said nozzle whereby a significant increase in pressure is produced within said nozzle to rapidly extinguish said arc.

Dependencies are inferred from the claim text.

Gas puffer type current interrupter and method

Life of this patent

Gas puffer type current interrupter and method

Life of this patent

Abstract

Claims17