US4479115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fan speed and/or fan failure detector
Assignee: Nokia Bell Labs
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Filing: 1982-12-20
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Granted: 1984-10-23
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Expires: 2002-12-20
Abstract
Abstract A pressure transducer, such as a microphone, is placed in proximity to the blades of a fan, such as a fan used to cool electronic equipment. As each blade passes the transducer, a pressure wave is generated that is converted into an electrical pulse by the transducer. Circuitry responsive to those pulses signals an alarm if the fan is not operating properly.
Inventors
- 👤 Norman H. Holzhauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:23
CPC Classifications
H; H05; H05K; H05K7/00; H05K7/20; H05K7/20009; H05K7/20209; G; G08; G08B; G08B21/00; G08B21/18; G08B21/187
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
85 words
Apparatus for use in conjunction with a fan, said apparatus comprising, transducer means for generating a stream of pulses in response to pressure waves impinging thereon, means adapted for mounting said transducer means in such proximity to said fan that the pressure waves generated by said fan when it is operating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 2
Dependent Claim
85 words
Apparatus for use in conjunction with a fan, said apparatus comprising, transducer means for generating a stream of pulses in response to pressure waves impinging thereon, means adapted for mounting said transducer means in such proximity to said fan that the pressure waves generated by said fan when it is operating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 3
Dependent Claim
88 words
Apparatus for use in conjunction with a fan, said apparatus comprising, transducer means for generating individual signals in response to respective pressure waves impinging on said transducer means, means adapted for mounting said transducer means on said fan in such proximity thereto that the pressure waves generated when said fan is operating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive ones of said individual signals and for providing an indication when said indicative signal reaches a predetermined threshold.
Claim 4
Dependent Claim
88 words
Apparatus for use in conjunction with a fan, said apparatus comprising, transducer means for generating individual signals in response to respective pressure waves impinging on said transducer means, means adapted for mounting said transducer means on said fan in such proximity thereto that the pressure waves generated when said fan is operating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive ones of said individual signals and for providing an indication when said indicative signal reaches a predetermined threshold.
Claim 5
Dependent Claim
50 words
Apparatus comprising a fan, transducer means for generating a stream of pulses in response to pressure waves generated by said fan, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 6
Dependent Claim
50 words
Apparatus comprising a fan, transducer means for generating a stream of pulses in response to pressure waves generated by said fan, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 7
Dependent Claim
60 words
Apparatus comprising a fan having at least one blade, each blade generating pressure waves when said fan is rotating, transducer means for converting said pressure waves into respective signals, and means for generating a signal indicative of the time interval between successive pairs of said respective signals and for providing an indication when said indicative signal reaches a predetermined threshold.
Claim 8
Dependent Claim
60 words
Apparatus comprising a fan having at least one blade, each blade generating pressure waves when said fan is rotating, transducer means for converting said pressure waves into respective signals, and means for generating a signal indicative of the time interval between successive pairs of said respective signals and for providing an indication when said indicative signal reaches a predetermined threshold.
Claim 9
Dependent Claim
87 words
Apparatus comprising a fan having one or more blades, transducer means for generating electrical pulses in response to pressure waves impinging thereon, means for mounting said transducer means in such proximity to said one or more blades that the pressure waves generated by said one or more blades when said fan is rotating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 10
Dependent Claim
87 words
Apparatus comprising a fan having one or more blades, transducer means for generating electrical pulses in response to pressure waves impinging thereon, means for mounting said transducer means in such proximity to said one or more blades that the pressure waves generated by said one or more blades when said fan is rotating impinge on said transducer means, and means for generating a signal indicative of the time interval between successive pairs of said pulses and for providing an indication when said signal reaches a predetermined threshold.
Claim 11
Dependent Claim
18 words
The invention of claims 1, 2, 3, 4 or 5 wherein said transducer means is an audio microphone.
Claim 12
Independent Claim
46 words
A method comprising the steps of generating electrical signals in response to respective pressure waves produced by a fan, generating a signal indicative of the time interval between successive pairs of said electrical signals, and providing an indication when said indicative signal reaches a predetermined threshold.
Claim 13
Independent Claim
46 words
A method comprising the steps of generating electrical signals in response to respective pressure waves produced by a fan, generating a signal indicative of the time interval between successive pairs of said electrical signals, and providing an indication when said indicative signal reaches a predetermined threshold.
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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |