Patent US4399701A successfully refreshed from Google Patents.
US4399701A
Expired / Lapsed
US
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Method and means for detecting decay in wood
Assignee: Unisearch Ltd
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Filing: 1981-05-29
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Granted: 1983-08-23
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Expires: 2001-05-29
Abstract
Abstract A method and apparatus for detecting degradation in wood by applying acoustic waves along the wood grain and measuring the bandwidths and frequencies or standing wave resonances induced in the wood as the frequency of the applied waves is varied. Good quality wood exhibits a substantially harmonic relationship between the frequencies at which resonances occur and the bandwidths of the resonances are relatively small.
Inventors
- 👤 John I. Dunlop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:53
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/12; G01N29/34; G01N29/348; G01N33/00; G01N33/46; G01N2291/00; G01N2291/02; G01N2291/023; G01N2291/0238; G01N2291/025; G01N2291/0258; G01N2291/04; G01N2291/042; G01N2291/0421
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
48 words
A method of detecting degradation in wood articles comprising the steps of applying acoustic waves along the wood grain, and measuring the band widths and frequencies of the acoustic or standing wave resonances in said articles as the frequency of said waves is varied over a predetermined range.
Claim 2
Independent Claim
48 words
A method of detecting degradation in wood articles comprising the steps of applying acoustic waves along the wood grain, and measuring the band widths and frequencies of the acoustic or standing wave resonances in said articles as the frequency of said waves is varied over a predetermined range.
Claim 3
Dependent Claim
16 words
A method as claimed in claim 1 wherein the acoustic waves are applied via a transducer.
Claim 4
Dependent Claim
43 words
Means for detecting degradation in wood articles comprising means for applying longitudinal acoustic waves to a wood article along the wood grain over a predetermined range of frequencies and means for detecting and recording the standing wave frequencies and resonance bandwidths associated therewith.
Claim 5
Dependent Claim
43 words
Means for detecting degradation in wood articles comprising means for applying longitudinal acoustic waves to a wood article along the wood grain over a predetermined range of frequencies and means for detecting and recording the standing wave frequencies and resonance bandwidths associated therewith.
Claim 6
Dependent Claim
23 words
Means for detecting degradation as claimed in claim 3, wherein the means for applying acoustic waves and the means for detecting are transducers.
Claim 7
Dependent Claim
18 words
Means for detecting degradation as claimed in claim 4, wherein said transducers are piezo electric bender disc transducers.
Claim 8
Dependent Claim
18 words
Means for detecting degradation as claimed in claim 4, wherein said transducers are rectangular bimorphic piezo-electric strip transducers.
Claim 9
Dependent Claim
23 words
Means for detecting degradation as claimed in claim 4, wherein the acoustic wave applying transducer is driven by a variable frequency voltage generator.
Claim 10
Dependent Claim
19 words
Means for detecting degradation as claimed in claim 4, wherein the detecting transducer is connected to voltage recording means.
References Cited (Backward Citations)
US3023609A
Cited
US3043132A
Cited
US3345861A
Cited
US3531983A
Cited
US3521483A
Cited
GB1302028A
Cited
US3877294A
Cited
US4297872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |