# US 2014/0151345 A1 · Method for magnetic control of plasma arc > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151345 A1 - Document ID: US20140151345A1 - Status: Published application - Kind: A1 - Application number: 13/900,983 - Filed: 2013-05-23 - Published: 2014-06-05 - Earliest claimed: 2012-05-24 - Assignees: Thermal Dynamics Corporation - Applicants: Thermal Dynamics Corporation - Inventors: Pieter Willen Jozef Zelis - Web page: https://patentgrep.com/patent/US20140151345A1 ## CPC - H05H 1/40: using applied magnetic fields, e.g. for focusing or rotating the arc {(cf. B23K9/08, B23K9/073)} - B23K 9/08: Arrangements or circuits for magnetic control of the arc - B23K 10/006: {Control circuits therefor} - H05H 1/50: and using applied magnetic fields, e.g. for focusing or rotating the arc - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM ## Abstract A device for controlling a plasma arc is provided that includes a plurality of magnetic poles disposed around a distal end portion of a plasma arc torch. A plurality of electrical coils are wound around a proximal end portion of each of the plurality of magnetic poles, and a plurality of lead wires are connected to the plurality of electrical coils. A control system for controlling a current supplied to the plasma arc torch through the lead wires is also provided that changes at least one of a strength of a magnetic field produced by the magnetic poles, a polarity of the magnetic poles, and a movement of a magnetic force between the plurality of magnetic poles, such that a size and location of the plasma arc is controlled. ## Claims ### Claim 1 A device for controlling a plasma arc comprising: a plurality of magnetic poles disposed around a distal end portion of a plasma arc torch; a plurality of electrical coils wound around a proximal end portion of each of the plurality of magnetic poles; a plurality of lead wires connected to the plurality of electrical coils; and a control system for controlling a current supplied to the plasma arc torch through the lead wires to change at least one of: a strength of a magnetic field produced by the magnetic poles, a polarity of the magnetic poles, and a movement of a magnetic force between the plurality of magnetic poles, such that a size and location of the plasma arc is controlled. ### Claim 2 (depends on 1) The device according to claim 1, wherein at least one of a current strength and a current waveform are controlled. ### Claim 3 (depends on 1) The device according to claim 1 further comprising four magnetic poles spaced radially and evenly around the distal end portion of the plasma arc torch. ### Claim 4 (depends on 1) The device according to claim 1, wherein each of the magnetic poles define a body extending axially along the plasma arc torch, the body having a distal end defining a radial projection, the radial projection extending inwardly towards the plasma arc. ### Claim 5 (depends on 4) The device according to claim 4, wherein the projection defines a tapered geometry. ### Claim 6 (depends on 4) The device according to claim 4, wherein the radial projections of the magnetic poles lie in a common plane. ### Claim 7 (depends on 1) The device according to claim 1, wherein the magnetic poles are disposed around an exterior of the plasma arc torch. ### Claim 8 (depends on 1) The device according to claim 1, wherein the magnetic poles are disposed around an interior of the plasma arc torch. ### Claim 9 (depends on 1) The device according to claim 1, wherein the magnetic poles comprise an iron steel. ### Claim 10 (depends on 1) The device according to claim 1, wherein the electrical coils define approximately six to approximately ten windings per inch. ### Claim 11 A method of controlling a plasma arc comprising: applying a current signal to a plurality of magnetic poles disposed around a plasma arc torch; controlling the current signal to change at least one of: a strength of a magnetic field produced by the magnetic poles, a polarity of the magnetic poles, and a movement of a magnetic force between the plurality of magnetic poles, such that a size and location of the plasma arc is controlled. ### Claim 12 (depends on 11) The method according to claim 11, wherein at least one of a current strength and a current waveform are controlled. ### Claim 13 (depends on 12) The method according to claim 12, wherein the current waveform comprises modulated DC waveforms offset 180 degrees from one magnetic pole to an adjacent magnetic pole. ### Claim 14 (depends on 11) The method according to claim 11, wherein the plurality of magnetic poles are selectively energized. ### Claim 15 A plasma arc torch comprising: a torch head defining a proximal end portion and a distal end portion; a plurality of magnetic poles disposed around the distal end portion of the torch head; a plurality of electrical coils wound around a proximal end portion of each of the plurality of magnetic poles; a plurality of lead wires connected to the plurality of electrical coils; and a control system for controlling a current supplied to the plasma arc torch through the lead wires to change at least one of: a strength of a magnetic field produced by the magnetic poles, a polarity of the magnetic poles, and a movement of a magnetic force between the plurality of magnetic poles, such that a size and location of a plasma arc is controlled. ### Claim 16 (depends on 15) The device according to claim 15, wherein each of the magnetic poles define a body extending axially along the plasma arc torch, the body having a distal end defining a radial projection, the radial projection extending inwardly towards the plasma arc. ### Claim 17 (depends on 16) The device according to claim 16, wherein the projection defines a tapered geometry. ### Claim 18 (depends on 16) The device according to claim 16, wherein the radial projections of the magnetic poles lie in a common plane. ### Claim 19 (depends on 15) The device according to claim 15, wherein the magnetic poles are disposed around an exterior of the torch head. ### Claim 20 (depends on 15) The device according to claim 15, wherein the magnetic poles are disposed around an interior of the torch head.