Thomas Robert Howarth

Author:

Thomas Howarth

ISBN #:

0710085389

Author:

Thomas Howarth

ISBN #:

0919876455

US Patent:

8030825, Oct 4, 2011

Filed:

Sep 19, 2008

Appl. No.:

12/284479

Inventors:

Thomas R. Howarth - Portsmouth RI, US

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

H01L 41/113

US Classification:

310339, 310329

Abstract:

An apparatus and method is provided to produce energy from movement of a user. At least one pair of plates is utilized to secure an array of cymbal transducers therebetween. The array of cymbal transducers is electrically interconnected with signal conditioning circuitry and power storage member. Electrical interconnections may comprise parallel and/or series connections between ones or groups of the cymbal transducers.

US Patent:

20020176592, Nov 28, 2002

Filed:

May 23, 2001

Appl. No.:

09/862345

Inventors:

Thomas Howarth - Portsmouth RI, US
James Tressler - Alexandria VA, US
Joseph Bucaro - Herndon VA, US

International Classification:

H04R025/00

US Classification:

381/190000, 381/152000, 381/173000

Abstract:

An acoustic actuator comprises a radially poled piezoelectric or electrostrictive drive element which is electroded on its inner and outer faces, and an acoustic diaphragm coupled to the upper surface of the piezoelectric drive element. As a voltage is applied to the electrodes, the piezoelectric drive element expands and contracts in the radial direction and the acoustic diaphragm displaces upward or downward, generating a sound wave. In an alternative embodiment, the piezoelectric or electrostrictive drive element is comprised of several subelements laid end to end and radially poled. In another embodiment, the piezoelectric or electrostrictive drive element is comprised of several subelements laid end to end which are thickness-poled reduced and internally biased oxide wafers of piezoelectric material.

US Patent:

47034645, Oct 27, 1987

Filed:

May 10, 1985

Appl. No.:

6/732332

Inventors:

Thomas R. Howarth - Portsmouth RI
Peter F. Flanagan - Cranston RI
William J. Harrold - Kingston RI
Kenneth Rodberg - East Providence RI

Assignee:

Raytheon Company - Lexington MA

International Classification:

H04R 1500

US Classification:

367156

Abstract:

A transducer which uses paramagnetic magnetostrictive rods or bars, e. g. , compositions of the lanthanide series of elements such as Tb. sub. 3 Dy. sub. 7 Fe. sub. 2, has the bars biased with a lengthwise flux by a permanent magnet, e. g. samarium-colbalt, of high resistance to demagnetization by the alternating field applied to the bars by alternating current in a coil surrounding the bar. The magnet is outside the coil to reduce the ac field to which it is subjected. Uniformity of flux density along the length of the bars is enhanced by having adjacent ends of the bars subjected to like-polarity poles of the permanent magnets associated with each bar.