US3694637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting tool wear
Assignee: INTERACTIVE SYSTEMS Inc
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Filing: 1970-10-22
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Granted: 1972-09-26
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Expires: 1990-10-22
Abstract
Abstract A method and apparatus for monitoring tool wear as a function of change in a power-frequency distribution obtained by Fourier analysis of a vibrational characteristic of the tool during use. Optimum tool change time is indicated by comparing a selected power spectrum or a selected portion thereof to a reference spectrum obtained from a test tool. A small general-purpose digital computer is employed in the analysis phase. A specially designed detector circuit for actual tool monitoring is also disclosed.
Inventors
- 👤 Allan I Edwin
- 👤 Thomas L Vlach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:02
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/406; G05B19/4065; G05B2219/00; G05B2219/30; G05B2219/34; G05B2219/34048; G05B2219/37; G05B2219/37256; G05B2219/37351
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
51 words
Apparatus for analyzing the wear characteristics of a machine tool comprising: an accelerometer for producing an output signal representing the vibration characteristic of an element in mechanical contact with the tool, and analyzer means responsive to the signal for providing frequency-power spectrum data of the vibration over a predetermined frequency range.
Claim 2
Dependent Claim
51 words
Apparatus for analyzing the wear characteristics of a machine tool comprising: an accelerometer for producing an output signal representing the vibration characteristic of an element in mechanical contact with the tool, and analyzer means responsive to the signal for providing frequency-power spectrum data of the vibration over a predetermined frequency range.
Claim 3
Dependent Claim
33 words
Apparatus as defined in claim 1 wherein said analyzer means comprises a digital computer for sampling said signal at a rate which is high relative to the highest frequency component in said characteristic.
Claim 4
Dependent Claim
28 words
Apparatus as defined in claim 2 wherein the computer is programmed to perform a Fourier analysis on the signal over a predetermined number of selected contiguous frequency bands.
Claim 5
Independent Claim
175 words
A method for determining the optimum tool wear condition at which to effect a tool change comprising the steps of: coupling a vibration transducer to the tool, obtaining a first relative power distribution representation over a broad frequency range of vibration measured by the transducer when the tool is in a relatively unworn condition; obtaining a second relative power distribution representation over a broad frequency range of vibration measured by the transducer when the tool is in a relatively worn condition; comparing the first and second power distribution representations to determine those relatively narrow frequency bands in which the largest power changes occur as between the worn and unworn tool conditions; coupling a transducer to at least one additional relatively unworn tool, operating the tool, obtaining a third relative power distribution representation comprising at least the said narrow frequency bands, and changing the tool when the power levels in each of said narrow frequency bands has undergone at least a substantial portion of the total change indicated between the first and second power distribution levels.
Claim 6
Independent Claim
175 words
A method for determining the optimum tool wear condition at which to effect a tool change comprising the steps of: coupling a vibration transducer to the tool, obtaining a first relative power distribution representation over a broad frequency range of vibration measured by the transducer when the tool is in a relatively unworn condition; obtaining a second relative power distribution representation over a broad frequency range of vibration measured by the transducer when the tool is in a relatively worn condition; comparing the first and second power distribution representations to determine those relatively narrow frequency bands in which the largest power changes occur as between the worn and unworn tool conditions; coupling a transducer to at least one additional relatively unworn tool, operating the tool, obtaining a third relative power distribution representation comprising at least the said narrow frequency bands, and changing the tool when the power levels in each of said narrow frequency bands has undergone at least a substantial portion of the total change indicated between the first and second power distribution levels.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |