Donald W Carkhuff

D3653455, Dec 19, 1995

May 27, 1994

D/023583

Donald W. Carkhuff - Florence SC

ESAB Welding Products, Inc. - Florence SC

D15144

41058917, Aug 8, 1978

Oct 4, 1976

5/729350

Clifford W. Hill - Florence SC
Donald W. Carkhuff - Florence SC
Frank J. Pilia - Florence SC

Union Carbide Corporation - New York NY

B23K 916

21913743

A metal inert gas welding torch having a wire guide assembly threadably secured at one end to a torch body and a collet nut assembly threadably secured to the other end of the wire guide assembly. A spidered collet is mounted in the collet nut assembly and forms a plenum chamber with the wire guide assembly and collet nut. A contact tip is gripped by the spidered collet and extends into the plenum chamber whereby the shielding gas cools the contact tip prior to the distribution of such gas into a nozzle.

54142377, May 9, 1995

Oct 14, 1993

8/136974

Donald W. Carkhuff - Florence SC

The ESAB Group, Inc. - Florence SC

B23K 1000

21912151

A plasma arc torch for minimizing delay in exchanging gases within the torch. The torch includes a metallic electrode, a conductive nozzle spaced apart from the electrode, and a gas plenum between the electrode and nozzle. Two gas passageways are provided for communicating non-oxidizing and oxidizing gases into the plenum. A plenum inlet check valve is associated with each gas passageway and is located in close proximity to the plenum. The check valves are normally biased in a closed position but may be opened by gas pressure within the passageways to selectively introduce gas into the plenum. Solenoid valves located upstream of the plenum check valves regulate the pressure and flow of gas within the passageways so as to open and close the plenum check valves. Pilot arc and main arc power supplies are provided for generating an arc between the electrode and nozzle while the non-oxidizing gas flows through the plenum and for transferring the arc and sustaining it between the electrode and workpiece when oxidizing gas is introduced into the plenum. Operation of the check valves and power supplies is coordinated so that the oxidizing and non-oxidizing gases are exchanged substantially simultaneously with transfer or termination of the arc.

52162214, Jun 1, 1993

Jan 17, 1992

7/822076

Donald W. Carkhuff - Florence SC

ESAB Welding Products, Inc. - Florence SC

B23K 900

21912151

A plasma arc torch has an outer heat shield removably secured onto the torch body. The heat shield includes an electrically conductive member secured on the interior surface of the heat shield and in electrical contact with the nozzle assembly or a nozzle assembly retainer member when the nozzle assembly and heat shield are secured onto the torch body. A closed loop electrical circuit is completed through a portion of the nozzle assembly and the electrically conductive member of the heat shield when both the nozzle assembly and the heat shield are secured onto the torch body. When the heat shield or the nozzle assembly are removed, the electrical circuit is open and the electrical voltage flow to the electrode is disabled.

43151264, Feb 9, 1982

May 29, 1980

6/154517

Peter R. Schaefer - Florence SC
Donald W. Carkhuff - Florence SC

Union Carbide Corporation - New York NY

B23K 900

219 70

An arc cutting and gouging torch in combination with nozzle assemblies for suspending a carbon electrode and discharging a combined air stream relative to the carbon electrode centerline. The nozzle assemblies include exit orifices which are disposed in a non-parallel alignment relative to one another and the electrode to cause the air jet discharged from each exit orifice to merge at a location upstream of the arc and substantially about the centerline of the electrode.

56814895, Oct 28, 1997

Dec 13, 1995

8/571709

Donald W. Carkhuff - Florence SC

The ESAB Group, Inc. - Florence SC

B23K 1000

21912148

A plasma arc torch includes a torch body defining a discharge axis, an electrode coaxially aligned on the discharge axis, a nozzle assembly positioned adjacent the discharge end of the electrode, and a heat shield removably secured on the torch body. A power supply delivers electrical current to the electrode to create an electrical arc, and a plasma gas is delivered so as to surround the arc. Also, a pressure sensing system is provided for sensing the pressure of the plasma gas and for disabling the power supply if there is insufficient gas pressure, such as when the heat shield is removed.

45800324, Apr 1, 1986

Dec 27, 1984

6/686749

Donald W. Carkhuff - Florence SC

Union Carbide Corporation - Danbury CT

B23K 900

219121PW

The plasma torch of the present invention includes safety control means which responds to the removal or partial removal of the torch heat shield from the torch body for interrupting the flow of plasma gas and a switch system responsive to the interruption of the flow of plasma gas for disengaging the power supply from the torch.

50138855, May 7, 1991

Feb 28, 1990

7/486070

Donald W. Carkhuff - Florence SC
Jeffrey S. Everett - Florence SC
Jule Conner - Marion SC

ESAB Welding Products, Inc. - Florence SC

B23K 900

2191215

A nozzle for use with a plasma arc torch having a first gas flow within the nozzle for engaging an electrode and generating a plasma and a second gas flow in surrounding engagement to the outer surface of the nozzle is disclosed. The nozzle includes an outer surface of substantially hourglass configuration in longitudinal cross-section so that the second gas remains in close contact with the outer hourglass surface of the nozzle to provide efficient heat transfer from the nozzle to the surrounding second gas flow.