Karl A Stetson from Coventry, CT, age 87

Processing Technique For Digital Speckle Photogrammetry

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US Patent:

20050228838, Oct 13, 2005

Filed:

Apr 10, 2003

Appl. No.:

10/409713

Inventors:

Karl Stetson - Coventry CT, US
Mark Rosenthal - Arlington MA, US

International Classification:

G06F007/00

US Classification:

708200000

Abstract:

An improved numerical technique is disclosed for processing digital photo-graphs for measuring surface strain by speckle photogrammetry. The data to be processed is obtained by recording two digital photographs of speckle patterns of the image of the surface of an object where one photograph is recorded before a stress is applied and the other recorded afterward. In the case of a vibratory stress, the recordings are made by illuminating the object stroboscopically first at one extreme of its vibration cycle for the first photograph and then at the other extreme for the second photograph. Each photograph is divided into sectors and digital Fourier transforms are performed on each sector. The phase of these transforms is calculated for each image sector on both photographs, the resulting phase functions from the unstressed recording are subtracted from the corresponding phase functions on the stressed recording, and the results wrapped into a numerical range of −pi to plus pi. The slopes in the x and y directions of the resulting difference functions are calculated for each sector and related by a scale factor to the displacement of the speckles in that sector of the recording. The x and y speckle displacements in the neighboring sectors forming two-by-two arrays are subtracted to obtain relative speckle displacements from which to calculate x strain, y strain, shear, and rotation about the surface normal.

Stringed Instrument With An Improved Back Plate Construction

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US Patent:

40610683, Dec 6, 1977

Filed:

Dec 17, 1975

Appl. No.:

5/641447

Inventors:

Karl A. Stetson - Coventry CT
Carl Hugo Agren - 184 00 Akersberga, SW

International Classification:

G10D 102

US Classification:

84275

Abstract:

A violin, as representative of any of the members of the viol and violin families, has a soundbox with an improved back plate construction. The back plate is substantially flat and has affixed to it braces for resonance balancing with the top plate. The braces include an elongate, primary brace disposed parallel to the longitudinal axis of the back plate, and first and second sets of secondary braces which are longitudinally spaced from each other. Each set of secondary braces comprises a pair of short, brace segments which are laterally disposed on the other side of the primary brace and in oppositely registering positions with respect thereto.

Apparatus For High Frequency Optical Beam Oscillation

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US Patent:

42616360, Apr 14, 1981

Filed:

Jan 4, 1979

Appl. No.:

6/001101

Inventors:

Karl A. Stetson - Coventry CT
Conrad M. Banas - Bolton CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

G02B 2717

US Classification:

350 66

Abstract:

A mechanical scanning apparatus adapted for oscillating the focus zone of a beam of radiation having high power to modify and control the nature and extent of the interaction zone on a workpiece is disclosed. The apparatus includes a compound beam adapted for being vibrated in a vibratory mode resulting in oscillatory motion of at least a first end of the compound beam; a reflective surface attached to the first end of the compound beam and adapted for focussing radiation incident thereon to a focus zone, and means for vibrating the compound beam to induce oscillatory motion of the reflective surface resulting in oscillatory motion of the focus zone. For vibration frequencies greater than the characteristic thermal response time of the workpiece material, the effect is a broadening of the interaction zone with a beam-material interaction characteristic of a reduced incident average power intensity while maintaining a high local intensity essential to the establishment of effective radiation-material coupling.

Optical Head For Shearography

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US Patent:

52570894, Oct 26, 1993

Filed:

Jun 15, 1992

Appl. No.:

7/898590

Inventors:

Karl A. Stetson - Coventry CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

G01B 902

US Classification:

356353

Abstract:

An optical head for a shearography system includes any standard TV camera lens 56, such as a wide-angle lens, which views a region of a test object 50 that is illuminated by coherent light 52. The lens 56 creates an image at an image plane where a field lens 80 is located. The field lens 80 redirects the light so as to allow substantially all the light of the image to pass through a first relay lens 86, thereby projecting the image with uniform brightness, i. e, no vignetting. The lens 86 provides collimated light 88,90 to a shearing element, such as a Michelson interferometer, comprising a beamsplitter 92 and two mirrors 94,96. Use of collimated light minimizes aberrations typically caused by beamsplitters. Collimated output light 102,104 from the shearing element is refocused onto a TV camera sensor plate 112 where the sheared interfered image is electronically detected for processing and viewing. The invention allows the shearing element to be sized independent of the size of the region on the object 50 to be imaged.

Optical Strain Gauge

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US Patent:

44364199, Mar 13, 1984

Filed:

Feb 16, 1982

Appl. No.:

6/349238

Inventors:

Karl A. Stetson - Coventry CT
Irene R. Harrison - Manchester CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

G01B 902

US Classification:

356 355

Abstract:

A noncontact optical strain gauge may be used for high temperature objects and objects having a small radius of curvature in the area of interest. The gauge works by means of interferometry applied to the speckle patterns of radiation reflected from two points on the object surface.

Method And Apparatus For High Frequency Optical Beam Oscillation

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US Patent:

43693482, Jan 18, 1983

Filed:

Sep 12, 1980

Appl. No.:

6/186867

Inventors:

Karl A. Stetson - Coventry CT
Conrad M. Banas - Bolton CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B23K 2700

US Classification:

219121LP

Abstract:

A mechanical scanning apparatus adapted for oscillating the focus zone of a beam of radiation having high power to modify and control the nature and extent of the interaction zone on a workpiece is disclosed. The apparatus includes a compound beam adapted for being vibrated in a vibratory mode resulting in oscillatory motion of at least a first end of the compound beam; a reflective surface attached to the first end of the compound beam and adapted for focussing radiation incident thereon to a focus zone, and means for vibrating the compound beam to induce oscillatory motion of the reflective surface resulting in oscillatory motion of the focus zone. For vibration frequencies greater than the characteristic thermal response time of the workpiece material, the effect is a broadening of the interaction zone with a beam-material interaction characteristic of a reduced incident average power intensity while maintaining a high local intensity essential to the establishment of effective radiation-material coupling.

Airflow Detection System Using Fiber Optics

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US Patent:

46395938, Jan 27, 1987

Filed:

Oct 29, 1984

Appl. No.:

6/665845

Inventors:

Karl A. Stetson - Coventry CT
John Palecki - Northampton MA

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

H01J 514
G01D 530
G01L 1100
G01F 166

US Classification:

250227

Abstract:

An airflow detection system comprising a light source for generating an optical signal that is propagated in an optical guide having a plurality of sensors responsive to the presence of airflow, each of which modulates the intensity of the optical signal at a frequency characteristic of that sensor such that a detection apparatus can receive the optical signal and identify activated sensors using frequency domain multiplexing techniques.