Chun Li

US Patent:

7135792, Nov 14, 2006

Filed:

May 11, 2005

Appl. No.:

11/127469

Inventors:

Thomas J. Devaney - Watchung NJ, US
Chun Li - Plainview NY, US

Assignee:

Dexter Magnetic Technologies, Inc. - Fremont CA

International Classification:

H02K 41/00

US Classification:

310 12

Abstract:

An embodiment of the invention is a particular arrangement of permanent magnets that generates a higher strength and more uniform magnetic field than existing permanent magnet arrangements for a voice coil motor. The permanent magnet arrangement of an embodiment is based on the Halbach arrangement of permanent magnets. The increased magnetic field strength and uniformity allows for a voice coil motor that is both capable of higher frequency actuations as well as more uniform force over the full stroke of the actuation.

US Patent:

8305177, Nov 6, 2012

Filed:

Jan 5, 2010

Appl. No.:

12/652621

Inventors:

Chun Li - Plainview NY, US
David Choit - Dix Hills NY, US

Assignee:

Dexter Magnetic Technologies, Inc. - Elk Grove Village IL

International Classification:

H01F 7/02

US Classification:

335306

Abstract:

A magnet assembly for decoupling a plurality of different types of magnetically operated security devices includes a center pole magnet having a magnetic orientation along a first direction. A plurality of magnets adjacent to and surrounding the center pole magnet define an opening above the center pole magnet. Each adjacent magnet has a magnetic orientation orthogonal to the first direction. An end pole magnet is disposed adjacent to one of the magnets adjacent to the center pole magnet. The end pole magnet has magnetic orientation opposed to the first direction.

US Patent:

8520333, Aug 27, 2013

Filed:

Apr 11, 2011

Appl. No.:

13/084012

Inventors:

Chun Li - Plainview NY, US

Assignee:

Dexter Magnetic Technologies, Inc. - Elk Grove Village IL

International Classification:

G11B 5/03
H01F 13/00

US Classification:

360 66, 361149

Abstract:

A structure for erasure of magnetic media in a hard drive includes a main field pole magnet polarized in a direction toward a drive spindle motor in the hard drive. At least two quadrature magnets are disposed adjacent the main field pole magnet and polarized in a direction toward the main field pole magnet. The main field pole magnet and the at least two quadrature magnets are shaped to provide a slot for insertion of the magnetic media. At least two inverse polarity magnets are disposed on portions of the main pole and quadrature magnets forming the slot. The inverse polarity magnets are polarized in a direction opposed to the direction of the main field pole magnet.

US Patent:

49804499, Dec 25, 1990

Filed:

Jul 14, 1988

Appl. No.:

7/219290

Inventors:

Joachim B. Kohn - Highland Park NJ
Chun Li - Piscataway NJ

Assignee:

Rutgers, The State University - Piscataway NJ

International Classification:

C08G 7300
C08G 6540

US Classification:

528211

Abstract:

Novel polyiminocarbonates having molecular weights exceeding 70,000 daltons. Novel solution polymerization and interfacial polymerization processes for the preparation of polyiminocarbonates in which cyanate compounds are reacted with diphenol compounds in the presence of a strong base catalyst.

US Patent:

51400944, Aug 18, 1992

Filed:

Jul 13, 1990

Appl. No.:

7/553224

Inventors:

Joachim B. Kohn - Highland Park NJ
Chun Li - Piscataway NJ

Assignee:

Rutgers, The State University - Piscataway NJ

International Classification:

C08G 7300
C08G 6540

US Classification:

528211

Abstract:

Novel polyiminocarbonates having molecular weights exceeding 70,000 daltons. Novel solution polymerization and interfacial polymerization processes for the preparation of polyiminocarbonates in which cyanate compounds are reacted with diphenol compounds in the presence of a strong base catalyst.

US Patent:

52645371, Nov 23, 1993

Filed:

Mar 5, 1992

Appl. No.:

7/846603

Inventors:

Joachim B. Kohn - Highland Park NJ
Chun Li - Piscataway NJ

Assignee:

Rutgers, The State University - Piscataway NJ

International Classification:

C08G 7300

US Classification:

528211

Abstract:

Novel polyiminocarbonates having molecular weights exceeding 70,000 daltons. Novel solution polymerization and interfacial polymerization processes for the preparation of polyiminocarbonates in which cyanate compounds are reacted with diphenol compounds in the presence of a strong base catalyst.

US Patent:

52429970, Sep 7, 1993

Filed:

Nov 19, 1992

Appl. No.:

7/978787

Inventors:

Joachim B. Kohn - Highland Park NJ
Chun Li - Piscataway NJ

Assignee:

Rutgers, The State University of New Jersey - New Brunswick NJ

International Classification:

C08G 6700

US Classification:

525534

Abstract:

Poly(N-phenyl urethanes) and methods of preparing same by heating poly(N-phenyl iminocarbonates) to a temperature above 250. degree. C. so that the backbone of the polyiminocarbonate rearranges to form the poly(N-phenyl urethane). Poly(N-substituted iminocarbonates and methods of preparing same by suspending a dialkaline diphenol in an aprotic solvent at a basic pH and adding to the suspension an N-substituted iminophosgene. Methods for making heat-stable articles by forming an article from a poly(N-phenyl iminocarbonate) while heating the article to a temperature above about 250. degree. C. so that the poly(N-phenyl iminocarbonate) rearranges to form a poly(N-phenyl urethane).