US3877294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibration technique for rot detection in wood poles and trees
Assignee: Fanner Manufacturing Co Pty Ltd
•
Filing: 1973-03-14
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Granted: 1975-04-15
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Expires: 1993-03-14
Abstract
Abstract A method of detecting for the presence of decay in a wooden pole, and which involves subjecting the pole to a mechanical vibrational force at a frequency falling within the sonic frequency range, measuring the level of energy emerging from the pole at a number of axially spaced points along the length of the pole (the energy being measured in terms of R.M.S. velocity or acceleration of vibrations) and comparing the measurements of the emergent energy at the respective points.
Inventors
- 👤 Alan Douglas Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:57
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/11; G01H; G01H5/00; G01N2291/00; G01N2291/02; G01N2291/023; G01N2291/0238
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
A method of detecting the presence of decay in a wooden pole, the method comprising the steps of: exciting said pole by a source of mechanical vibration at frequencies falling within the sonic frequency range, said source of mechanical vibration being applied at a selected peripheral one point along the length of said pole; measuring emergent energy transmitted through said pole at a number of selected longitudinally spaced other points along the length of the pole, including at a point substantially opposed to said one point of application of said vibrations; comparing the relative emergent energy levels at the respective said other points; and detecting for a predetermined relative increase in the level of emergent energy at selected ones of the longitudinally spaced said other points, such an increase in emergent energy level being an indication of the presence of decay within the pole.
Claim 2
Independent Claim
144 words
A method of detecting the presence of decay in a wooden pole, the method comprising the steps of: exciting said pole by a source of mechanical vibration at frequencies falling within the sonic frequency range, said source of mechanical vibration being applied at a selected peripheral one point along the length of said pole; measuring emergent energy transmitted through said pole at a number of selected longitudinally spaced other points along the length of the pole, including at a point substantially opposed to said one point of application of said vibrations; comparing the relative emergent energy levels at the respective said other points; and detecting for a predetermined relative increase in the level of emergent energy at selected ones of the longitudinally spaced said other points, such an increase in emergent energy level being an indication of the presence of decay within the pole.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1 wherein said spaced other points are located along a peripherally axial line which is diametrically opposed to said one point.
Claim 4
Dependent Claim
55 words
A method as claimed in claim 1 wherein the emergent energy levels at said respective axially spaced other points is measured by a transducer which provides an output signal representative of the R.M.S. velocity or the acceleration of mechanical vibrations occuring at said other points, said transducer being connected in circuit with a read-out device.
Claim 5
Dependent Claim
14 words
A method as claimed in claim 3 wherein said transducer comprises a piezo-electric device.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 3 wherein a single said transducer is applied in succession to each of said axially spaced other points.
Claim 7
Dependent Claim
36 words
A method as claimed in claim 3 wherein a said transducer is applied to each of said axially spaced outer points, each transducer being selectively connected in circuit with said read-out device by a switching mechanism.
Claim 8
Dependent Claim
19 words
A method as claimed in claim 2 wherein said mechanical vibrations are applied by way of an electro-magnetic vibrator.
Claim 9
Dependent Claim
20 words
A method as claimed in claim 7 wherein said vibrator is energised by a signal delivered by a square-wave oscillator.
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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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |