Heritage Community Foundation Presentss
Alberta Online Encyclopedia
Alberta Inventors and Inventions - A Century of Patents homeinfosearchsitemapcontactedukit
inventors
inventions
innovation
patents

     

Heritage Community Foundation
Alberta Innovation and Science
Canada's Digital Collections
Visit AlbertaSource.ca

Wood Slope-of-Grain Indicator (Patent No: 943187)

Inventor: McLauchlan, Thomas A.

Location: Vancouver, BC

Comments: N/A

Description: [52] CLASS 324-2
[11] 943,187
[54] WOOD SLOPE-OF-GRAIN INDICATOR
[72] Norton, John A. P., Calgary, Alberta, Canada, McLauchlan, Thomas A., Vancouver, British Columbia, Canada, and Kusec, Davor J., Richmond, British Columbia, Canada
[73] Granted to Majesty (Her) in right of Canada as represented by the Minister of the Environment, Ottawa, Ontario, Canada
[21] Application No. 147,037
[22] Filed June 29, 1972
6 Claims

[57] A method and apparatus for detecting wood grain slope by measuring the direction of the maximum and minimum electrical capacitance with respect to the axis of a piece of lumber. The method comprises rotating a pair of electrically energized capacitor plates closely adjacent a surface of the piece of lumber under test, measuring the sinusoidal variations in the capacitance value obtained as an analogue signal, comparing this signal as to phase with a reference signal related in frequency to the rotation of the capacitor plates, said phase relation being indicative of the direction of grain. The apparatus comprises a pair of spaced flat capacitor plates formed in the surface of a circular disc over which the wood workpiece would travel, means for rotating the disc at a precise rotation speed, means for measuring the sinusoidally varying capacitance in the form of a voltage, means for comparing the phase of this voltage with the phase of a reference AC voltage whose frequency is directly related to the rotation speed of the disc, and whose phase corresponds to zero slope-of-grain, means for measuring variations in phase displacement, said variations being directly related to variations of the grain slope of the wood from parallel to the wood piece axis. For three dimensional indicators two similar devices are placed at right angles such that two surfaces of the lumber are scanned at the same time.

[<<back]


Albertasource.ca | Contact Us | Partnerships
For more on innovation and invention in Alberta , visit Peel’s Prairie Provinces.
Copyright © Heritage Communty Foundation All Rights Reserved