Richard A Spaulding

US Patent:

46910948, Sep 1, 1987

Filed:

May 20, 1986

Appl. No.:

6/865256

Inventors:

Bruce O. Hatch - Lebanon NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

International Classification:

B23K 1500

US Classification:

219121PR

Abstract:

A plasma-arc torch includes an interlock in the form of a sliding gas valve which permits interruption of torch operation by closing off fluid flow through the torch when necessary parts such as the electrode, tip, fluid distributor, and/or cup are not in place.

US Patent:

D320975, Jul 11, 1989

Filed:

Feb 3, 1986

Appl. No.:

6/823858

Inventors:

Richard A. Spaulding - Hanover NH
Pearl A. Grant - Grantham NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

US Classification:

D 8 30

US Patent:

46635157, May 5, 1987

Filed:

Nov 4, 1985

Appl. No.:

6/794389

Inventors:

Robert D. Kneeland - Enfield NH
Bruce O. Hatch - Lebanon NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

International Classification:

B23K 1500

US Classification:

219121PT

Abstract:

A plasma-art torch interlock with flow sensing is provided. A flow rate sensor is included within the conduit supplying working fluid to a plasma-arc torch. By sensing an increase in flow rate of the working fluid which is caused by a necessary part being not in place, a control circuit shuts off power to the torch. Pressure in the conduit may also be sensed and the power to the torch shut down if a minimum pressure needed for torch operation is not achieved. In a second embodiment, two conduits are provided to supply fluid to the torch. One conduit supplies the primary working fluid to create the plasma-arc while the other supplies secondary flow for purposes of cooling.

US Patent:

D2993520, Jan 10, 1989

Filed:

Jun 11, 1985

Appl. No.:

6/742291

Inventors:

Richard A. Spaulding - Hanover NH
Pearl A. Grant - Grantham NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

US Classification:

D15144

US Patent:

46635122, May 5, 1987

Filed:

Nov 4, 1985

Appl. No.:

6/794288

Inventors:

Robert D. Kneeland - Enfield NH
Bruce O. Hatch - Lebanon NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

International Classification:

B23K 900
B23K 902

US Classification:

219121PU

Abstract:

A plasma-arc torch interlock with pressure sensing is provided. A pressure sensor is included within the conduit supplying working fluid to a plasma-arc torch. By sensing a decrease in pressure of the working fluid which is caused by a necessary part being not in place, a control circuit shuts off power to the torch. In a second embodiment, two conduits are provided to supply fluid to the torch. One conduit supplies the primary working fluid to create the plasma-arc while the other supplies secondary flow for purposes of cooling.

US Patent:

D2953617, Apr 26, 1988

Filed:

Jun 11, 1985

Appl. No.:

6/742292

Inventors:

Pearl A. Grant - Grantham NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

US Classification:

D 8 30

US Patent:

47483121, May 31, 1988

Filed:

Apr 10, 1986

Appl. No.:

6/850504

Inventors:

Bruce O. Hatch - Lebanon NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

International Classification:

B23K 900

US Classification:

219121PR

Abstract:

A plasma-arc cutting torch housing defines a chamber which has an outlet at the end of the housing. The torch also includes an electrode in the chamber near the outlet and a provision in the chamber for separating the gas flowing towards the outlet of the housing into a primary gas flow adjacent to the electrode for generating a plasma and a secondary gas flow away from the electrode for cooling the torch and the workpiece. The electrode has a centrally disposed bore therethrough for conveying gas. An insert in the workpiece end of the electrode burns away so as to expose the essentially disposed bore therethrough, thereby automatically quenching operation of the plasma arc so as to minimize damage to the torch. In the preferred embodiment, the electrode has a stepped centrally disposed bore which stops short of the insert. In an alternate embodiment, the stepped bore extends through to the insert and accommodating insert bore.

US Patent:

45815160, Apr 8, 1986

Filed:

Jul 20, 1983

Appl. No.:

6/515913

Inventors:

Bruce O. Hatch - Lebanon NH
Richard A. Spaulding - Hanover NH

Assignee:

Thermal Dynamics Corporation - West Lebanon NH

International Classification:

B23K 900

US Classification:

219121PM

Abstract:

In the plasma arc torch of this invention the same gas may be used for generating a plasma and for secondary gas flow for cooling the torch and the workpiece. A torch housing defines a chamber which has an outlet at the end of the housing. The torch also includes an electrode in the chamber near the outlet and means in the chamber for separating the gas flowing towards the outlet of the housing into a primary gas flow adjacent to the electrode for generating a plasma and a secondary gas flow away from the electrode for cooling the torch and the workpiece. In the preferred embodiment, air may be used for both the plasma forming gas and the secondary gas and the electrode has a halfnium insert. The torch has a torch tip adjacent to the electrode and the torch may be started without a pilot arc by touching the workpiece with the torch tip. No standoff between the electrode and the workpiece needs to be maintained and the torch operator simply drags the torch tip on the workpiece resulting in a more accurate cut or weld.