US4123702A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for classifying and measuring of timbers
Assignee: Individual
•
Filing: 1977-09-22
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Granted: 1978-10-31
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Expires: 1997-09-22
Abstract
Abstract Lumber is classified in terms of knots. The method used employs high frequency radio energy and a detector responsive to phase to detect the energy passing through the lumber. The knots exhibit a different dielectric constant, the real part of which is different from normal wood, and the difference in phase of the radiation detected effects the measurement. Preferably, the frequency radiation is near 10 GHz.
Inventors
- 👤 Ilmari Kinanen
- 👤 Jim Duncker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:06
CPC Classifications
G; G01; G01N; G01N22/00; G01N33/00; G01N33/46; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2617; G01R27/2635; G01R27/2658
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
119 words
A method for sorting out and classifying timber in terms of knots characterized in that frequency modulated radio energy in the microwave range is applied from at least one transmitting antenna to one side of the lumber, which is passed in front of the antenna; on the other side of the lumber is a receiving antenna; a portion of the frequency modulated signal applied to the lumber is delayed so that at operating frequency the phase of this reference signal is, opposite to the phase of signal coupled through the receiving antenna, the change of frequency at which the sum of the two detected signals is at minimum is a measure of the phase shift caused by the knot.
Claim 2
Independent Claim
119 words
A method for sorting out and classifying timber in terms of knots characterized in that frequency modulated radio energy in the microwave range is applied from at least one transmitting antenna to one side of the lumber, which is passed in front of the antenna; on the other side of the lumber is a receiving antenna; a portion of the frequency modulated signal applied to the lumber is delayed so that at operating frequency the phase of this reference signal is, opposite to the phase of signal coupled through the receiving antenna, the change of frequency at which the sum of the two detected signals is at minimum is a measure of the phase shift caused by the knot.
References Cited (Backward Citations)
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US3534260A
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US3498112A
Cited
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Cited
US3810005A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-30 | 1982-05-01 | 1982-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-30 | 1986-05-01 | 1986-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-30 | 1990-05-01 | 1990-10-31 | $7700.00 | Window Closed / Lapsed |