Richard A Madden

US Patent:

6422089, Jul 23, 2002

Filed:

Apr 26, 2001

Appl. No.:

09/842564

Inventors:

Richard Madden - Groton MA
Daniel Joseph McCarthy - Cambridge MA
Gary L. Thomas - Hingham MA

Assignee:

BBNT Solutions LLC - Cambridge MA

International Classification:

G01B 500

US Classification:

73779, 73780

Abstract:

A variable reluctance load cell for measuring the static or slowly fluctuating load, or tension, on devices is contained in a support tube. A sensor in the tube utilizes opposing C and I shaped magnetic cores attached to opposing ends of the support tube. A magnetic circuit is formed having an inductance defined by the size of the gap between the magnetic cores with the reluctance dominated by the gap. The sensor inductance is coupled with a fixed, predetermined capacitance in a resonant LC circuit, and the resonant frequency is a function of the gap. The sensor is in a cavity within the tube, and the cavity is sealed in a manner that prevents water or other damaging agents from entering the sensor. In this manner, mounting the sensor and tube to a static device and measuring the AC voltage at the sensor, the amount of load, or stress can be determined.

US Patent:

6752029, Jun 22, 2004

Filed:

May 3, 2002

Appl. No.:

10/138272

Inventors:

Richard Madden - Groton MA
Daniel Joseph McCarthy - Cambridge MA
Gary L. Thomas - Hingham MA

Assignee:

BBNT Solutions LLC - Cambridge MA

International Classification:

G01L 112

US Classification:

7386269

Abstract:

A variable reluctance load cell for measuring the static or slowly fluctuating load, or tension, on devices is contained in a support tube. A sensor in the tube utilizes opposing C and I shaped magnetic cores attached to opposing ends of the support tube. A magnetic circuit is formed having an inductance defined by the size of the gap between the magnetic cores with the reluctance dominated by the gap. The sensor inductance is coupled with a fixed, predetermined capacitance in a resonant LC circuit, and the resonant frequency is a function of the gap. The sensor is in a cavity within the tube, and the cavity is sealed in a manner that prevents water or other damaging agents from entering the sensor. In this manner, mounting the sensor and tube to a static device and measuring the AC voltage at the sensor, the amount of load, or stress can be determined.

US Patent:

6880408, Apr 19, 2005

Filed:

Feb 28, 2003

Appl. No.:

10/376083

Inventors:

Richard Madden - Groton MA, US
Bruce Stuart Murray - Winchester MA, US

Assignee:

BBNT Solutions LLC - Cambridge MA

International Classification:

G01L001/00

US Classification:

73782

Abstract:

A mechanical amplifier includes first and second amplifier mounting pads () and first and second sensor mounting pads (). At least one of the first and second amplifier mounting pads () receives a load or displacement. The first and second sensor mounting pads () connect to the first and second amplifier mounting pads () via flexible connecting members. A sensor () may connect to the first and second sensor mounting pads to measure the amount of load or displacement.

US Patent:

7493827, Feb 24, 2009

Filed:

Sep 30, 2005

Appl. No.:

11/240683

Inventors:

Richard Madden - Groton MA, US
Daniel Joseph McCarthy - Cambridge MA, US
Gary L. Thomas - Hingham MA, US

Assignee:

Oil States Industries, Inc. - Arlington TX

International Classification:

G01B 5/00

US Classification:

73779

Abstract:

A variable reluctance load cell for measuring the static or slowly fluctuating load, or tension, on devices is contained in a support tube. A sensor in the tube utilizes opposing C and I shaped magnetic cores attached to opposing ends of the support tube. A magnetic circuit is formed having an inductance defined by the size of the gap between the magnetic cores with the reluctance dominated by the gap. The sensor inductance is coupled with a fixed, predetermined capacitance in a resonant LC circuit, and the resonant frequency is a function of the gap. The sensor is in a cavity within the tube, and the cavity is sealed in a manner that prevents water or other damaging agents from entering the sensor. In this manner, mounting the sensor and tube to a static device and measuring the AC voltage at the sensor, the amount of load, or stress can be determined.

US Patent:

8095367, Jan 10, 2012

Filed:

Oct 30, 2007

Appl. No.:

11/929068

Inventors:

Ronald Bruce Coleman - Arlington MA, US
John Scott Knight - Cambridge MA, US
George Shepard - Cambridge MA, US
Richard Madden - Groton MA, US

Assignee:

Raytheon BBN Technologies Corp. - Cambridge MA

International Classification:

G10L 21/00

US Classification:

704272, 704231, 704274, 704278

Abstract:

Methods and systems of parasitic sensing are shown and described. The method includes, measuring, at a first time using one or more electrical elements native to a domain, a parameter of a circuit within the domain and measuring, at a second time using the one or more electrical elements native to the domain, the parameter. The method also includes, comparing the parameter measurement from the first time to the parameter measurement at the second time and determining, in response to the comparison, that an activity occurred within the domain.

US Patent:

20050028606, Feb 10, 2005

Filed:

May 17, 2004

Appl. No.:

10/848525

Inventors:

Richard Madden - Groton MA, US
Daniel McCarthy - Cambridge MA, US
Gary Thomas - Hingham MA, US

Assignee:

BBNT SOLUTIONS LLC - Cambridge MA

International Classification:

G01L001/00

US Classification:

073779000

Abstract:

A variable reluctance load cell for measuring the static or slowly fluctuating load, or tension, on devices is contained in a support tube. A sensor in the tube utilizes opposing C and I shaped magnetic cores attached to opposing ends of the support tube. A magnetic circuit is formed having an inductance defined by the size of the gap between the magnetic cores with the reluctance dominated by the gap. The sensor inductance is coupled with a fixed, predetermined capacitance in a resonant LC circuit, and the resonant frequency is a function of the gap. The sensor is in a cavity within the tube, and the cavity is sealed in a manner that prevents water or other damaging agents from entering the sensor. In this manner, mounting the sensor and tube to a static device and measuring the AC voltage at the sensor, the amount of load, or stress can be determined.

US Patent:

59526211, Sep 14, 1999

Filed:

Apr 15, 1998

Appl. No.:

9/060070

Inventors:

Alan R. D. Curtis - Acton MA
Richard Madden - Groton MA
Paul J. Remington - Sudbury MA

Assignee:

GTE Internetworking Incorporated - Cambridge MA

International Classification:

B64D 3302

US Classification:

181213

Abstract:

The present invention is noise attenuation system and related method for suppressing noise generated by a noise source, such as a jet engine, contained in a housing. An impedance device is positioned in the housing to attenuate the amplitude of sound waves generated by the noise source propagating in one direction and to create a reflected sound wave. The reflected sound wave is out of phase with the sound waves propagating from the noise source away from the impedance device. The reflected sound wave destructively interferes with this sound wave to attenuate the amplitude.

US Patent:

53599020, Nov 1, 1994

Filed:

Jul 15, 1993

Appl. No.:

8/092127

Inventors:

James E. Barger - Winchester MA
Richard Madden - Groton MA

Assignee:

Bolt Beranek and Newman Inc. - Cambridge MA

International Classification:

G01L 100

US Classification:

73862626

Abstract:

In the load cell disclosed herein, relative displacement between bridging members or end caps mounted at different points along the axis of an elastic hollow cylinder is sensed by means of a variable reluctance transducer employing a pair of magnetically permeable core elements. One of the core elements is mounted on one of the bridging members and the other core element is C-shaped and mounted on the other bridging member with the ends of the C-shape in close proximity to the first core member thereby providing magnetic gaps whose widths are aligned with the cylinder axis. Windings around the ends of the C-shaped core provide electrical connection for an inductance which is variable as a function of the widths of the gaps and thus also of the axial displacement between the bridging members.