Richard Corey Eschenbach

US Patent:

6452129, Sep 17, 2002

Filed:

Nov 20, 2000

Appl. No.:

09/717487

Inventors:

Wenxian Zhu - San Jose CA
Richard C. Eschenbach - Ukiah CA
Robin A. Lampson - Ukiah CA
John R. Sparkes - Ukiah CA

Assignee:

Retech Systems LLC - Ukiah CA

International Classification:

B23K 1000

US Classification:

2191215, 219 75, 21912151, 31323151

Abstract:

A plasma arc torch is disclosed which has an elongated electrode with an open front and a nozzle with a plasma discharge opening that is coaxial with the electrode. A mounting arrangement includes a ceramic ring that engages the front end of the electrode and a gas ring which concentrically surrounds the ceramic ring. A forward portion of the gas ring, the forward end of the electrode, and the nozzle define a swirl chamber of the torch, and opposing, spaced-apart concentric cylindrical surfaces of the ceramic ring and the gas ring, respectively, form an annulus which extends rearwardly from the swirl chamber. The ceramic ring closes the aft end of the annulus, and the gas ring houses a plurality of plasma gas injection ports which are located immediately forward of the aft end of the annulus. The entire plasma gas for the torch flows from the injection ports generally tangentially into the annulus to prevent a recirculation of gas into the annulus and to impart rotation to the gas after it leaves the ports and as it propagates towards the swirl chamber. The annulus is sufficiently long so that the injected gas spirals through about 5-20 revolutions before it enters the swirl chamber as a substantially uniform, single mass gas flow.

US Patent:

63134292, Nov 6, 2001

Filed:

Aug 27, 1998

Appl. No.:

9/140492

Inventors:

Robin A. Lampson - Ukiah CA
Robert E. Haun - Ukiah CA
Roger S. Brooks - Ukiah CA
Richard C. Eschenbach - Ukiah CA

Assignee:

Retech Services, Inc. - Ukiah CA

International Classification:

B23K 906

US Classification:

21912157

Abstract:

A plasma arc torch that is capable of operating in a non-transferred arc mode and a transferred arc mode, and that is intended for use for use with a plasma arc treatment system. The plasma arc torch includes an electrode, a plasma gas ring and a nozzle. At least one power supply within the plasma arc treatment system is connected to the electrode, the nozzle and a workpiece. While the torch operates in a non-transferred arc mode, the non-transferred arc heats gas supplied by the plasma gas ring to create plasma gas that heats the workpiece to raise its conductivity. Once the workpiece is at an appropriately conductive level, the arc is automatically transferred since the ground point can now be found.