The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1976
Filed:
Jun. 21, 1974
David Grigorievich Bykhovsky, Leningrad, SU;
Alexandr Yakovlevich Medvedev, Leningrad, SU;
Alexandr Yakovlevich Finkelshtein, Leningrad, SU;
Jury Alexandrovich Bogorodsky, Leningrad, SU;
Mikhail Isaakovich Zax, Leningrad, SU;
Other;
Abstract
In a method for striking a main arc between the electrode and nozzle of a plasmatron there is initiated with the aid of high-frequency discharge an intermittently-arcing pilot arc whose flame bridges under the influence of a gas fed into the plasmatron the gap between the electrode of plasmatron and workpiece, completing thereby the circuit of main arc. The amplitude of pilot arc current is selected so as to be roughly equal to the steady current of the main arc whereas the frequency and on-off time ratio of the current are selected so as to assure that the flame of pilot arc is sustained unceasingly throughout the arcing of visually-monitored pilot arc. The method for striking a main arc is embodied in an apparatus wherein the electrode and nozzle of the plasmatron are connected to opposing terminals of a source of power so that interconnected between the electrode and nozzle of plasmatron there is an oscillator and between the nozzle and source of power is a RC-circuit serving as a switching device in the electrode-to-nozzle circuit and, further, the nozzle and workpiece are interconnected by the RC-circuit and an inductance, L, connected in series.