Devendra Kumar

US Patent:

6454877, Sep 24, 2002

Filed:

Jun 28, 2000

Appl. No.:

09/582607

Inventors:

Devendra Kumar - Rochester Hills MI
Satyendra Kumar - Troy MI
Michael L. Dougherty - Rochester Hills MI

Assignee:

Dana Corporation - Toledo OH

International Classification:

B23K 2614

US Classification:

148222, 148224, 148239, 148565, 21912166, 21912185

Abstract:

A method and apparatus are provided for treating the surface of a metal body through phase transformation, ion implantation, and/or diffusion and to form new phases of metallic materials. The method and apparatus have been shown to be particularly useful to improve the hardness and corrosion resistance of ferrous and non-ferrous metals. Generally, the method comprises irradiating a portion of the metal body ( ) with a laser ( ), and directing a stream of gas ( ) onto the same portion of the metal body simultaneously with and preferably for a duration after the laser is turned off. Preferably, the laser ( ) is a carbon dioxide laser operated in a pulsed mode to control heating of the metal ( ). The gas ( ) is preferably carbon dioxide to quickly cool the metal when the laser is off, and to provide carbon atoms for deposition onto the body. The entire process may be carried out in an environment at atmospheric pressure, obviating the need for a vacuum chamber or pressure controlled furnace or similar apparatus.

US Patent:

6658118, Dec 2, 2003

Filed:

Dec 6, 1999

Appl. No.:

09/445373

Inventors:

Satyendra Kumar - Troy MI
Devendra Kumar - Rochester Hills MI
Michael J. Dougherty - Rochester Hills MI

Assignee:

Dana Corporation - Toledo OH

International Classification:

A61F 1106

US Classification:

381 711, 181206

Abstract:

Apparatus for suppressing fluid-borne noise in a fluid conduit ( or ) that includes a vibration sensor ( or ) for operative coupling to the conduit for providing an electrical sensor signal as a function of fluid pressure fluctuations in the conduit. A piezoelectric actuator ( or ) is adapted to be mounted on the conduit for imparting pressure fluctuations to fluid in the conduit. An electronic controller ( or ) is responsive to the sensor signal for energizing the actuator 180Â out of phase with fluid pressure fluctuations sensed by the sensor. The sensor may be either closely coupled to the actuator, or separate from the actuator and disposed upstream of the actuator with respect to the direction of fluid flow through the conduit. The sensor in the preferred embodiments of the invention comprises a piezoelectric sensor, and the actuator comprises a stack of piezoelectric elements.

US Patent:

6870124, Mar 22, 2005

Filed:

May 7, 2003

Appl. No.:

10/430414

Inventors:

Devendra Kumar - Rochester Hills MI, US
Satyendra Kumar - Troy MI, US

Assignee:

Dana Corporation - Toledo OH

International Classification:

B23K009/02

US Classification:

21912146, 21912136, 219693

Abstract:

Methods and apparatus for plasma-assisted joining of one or more parts together are provided. The joining process may include, for example, placing at least first and second joining areas in proximity to one another in a cavity, forming a plasma in the cavity by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst, and sustaining the plasma at least until the first and second joining areas are joined. Plasma catalysts, and methods and apparatus for igniting, modulating, and sustaining a joining plasma, are provided. Additional cavity shapes, and methods and apparatus for selective plasma-joining, are also provided.

US Patent:

7132621, Nov 7, 2006

Filed:

May 7, 2003

Appl. No.:

10/430426

Inventors:

Satyendra Kumar - Troy MI, US
Devendra Kumar - Rochester Hills MI, US

Assignee:

Dana Corporation - Toledo OH

International Classification:

B23K 10/00

US Classification:

21912159, 21912141, 21912157, 118723 MW, 1563454, 20428838

Abstract:

Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for various plasma processes and treatments. In one embodiment, a plasma is ignited by subjecting a gas in a multi-mode processing cavity to electromagnetic radiation having a frequency between about 1 MHz and about 333 GHz in the presence of a plasma catalyst, which may be passive or active. A passive plasma catalyst may include, for example, any object capable of inducing a plasma by deforming a local electric field. An active plasma catalyst can include any particle or high energy wave packet capable of transferring a sufficient amount of energy to a gaseous atom or molecule to remove at least one electron from the gaseous atom or molecule, in the presence of electromagnetic radiation.

US Patent:

7189940, Mar 13, 2007

Filed:

Jun 2, 2003

Appl. No.:

10/449600

Inventors:

Satyendra Kumar - Troy MI, US
Devendra Kumar - Rochester Hills MI, US

Assignee:

BTU International Inc. - N. Billerica MA

International Classification:

B23K 10/00

US Classification:

21912143, 2191214, 21912159, 21912136, 373 18, 588900

Abstract:

Apparatus and methods for plasma-assisted melting are provided. In one embodiment, a plasma-assisted melting method can include: (1) adding a solid to a melting region, (2) forming a plasma in a cavity by subjecting a gas to electromagnetic radiation having a frequency less than about 333 GHz in the presence of a plasma catalyst, wherein the cavity has a wall, (3) sustaining the plasma in the cavity such that energy from the plasma passes through the wall into the melting region and melts the solid into a liquid, and (4) collecting the liquid. Solids that can be melted consistent with this invention can include metals, such as metal ore and scrap metal. Various plasma catalysts are also provided.

US Patent:

7214280, May 8, 2007

Filed:

May 7, 2003

Appl. No.:

10/430416

Inventors:

Devendra Kumar - Rochester Hills MI, US
Satyendra Kumar - Troy MI, US

Assignee:

BTU International Inc. - N. Billerica MA

International Classification:

C22F 3/00

US Classification:

148525, 148565, 20415744

Abstract:

Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for at least partially decrystallizing a surface of an object. In one embodiment, a method is provided for decrystallizing a surface of an object by forming a plasma (such as by subjecting a gas to an amount of electromagnetic radiation, optionally in the presence of a plasma catalyst) and exposing the surface of the object to the plasma.

US Patent:

7227097, Jun 5, 2007

Filed:

May 7, 2003

Appl. No.:

10/430415

Inventors:

Satyendra Kumar - Troy MI, US
Devendra Kumar - Rochester Hills MI, US

Assignee:

BTU International, Inc. - N. Billerica MA

International Classification:

B23K 10/00

US Classification:

21912143, 21912141, 21912148, 21912157, 15634538

Abstract:

Plasma-assisted methods and apparatus that use multiple radiation sources are provided. In one embodiment, a plasma is ignited by subjecting a gas in a processing cavity to electromagnetic radiation having a frequency less than about 333 GHz in the presence of a plasma catalyst, which may be passive or active. A controller can be used to delay activation of one radiation source with respect to another.

US Patent:

7309843, Dec 18, 2007

Filed:

Oct 21, 2004

Appl. No.:

10/971180

Inventors:

Devendra Kumar - Rochester Hills MI, US
Satyendra Kumar - Troy MI, US

Assignee:

BTU International, Inc. - N. Billerica MA

International Classification:

B23K 9/02

US Classification:

21912159, 21912146, 21912136

Abstract:

Methods and apparatus for plasma-assisted joining of one or more parts together are provided. The joining process may include, for example, placing at least first and second joining areas in proximity to one another in a cavity, forming a plasma in the cavity by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst, and sustaining the plasma at least until the first and second joining areas are joined. Plasma catalysts, and methods and apparatus for igniting, modulating, and sustaining a joining plasma, are provided. Additional cavity shapes, and methods and apparatus for selective plasma-joining, are also provided.