US4218879A
Expired / Lapsed
US
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Overspeed protection device
Assignee: McDonnell Douglas Corp
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Filing: 1978-10-30
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Granted: 1980-08-26
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Expires: 1998-10-30
Abstract
Abstract An overspeed protection system is provided which utilizes simplified construction for detecting overspeed conditions of a rotating device. In the preferred embodiment, a single up/down counter is employed in an overall sequence which includes a first time period during which the counter is counted up from a preselected value by a series of pulse representations of speed for the rotating device. After the expiration of the first time period of the sequence, the counter value is compared to an overspeed limit selected during the previous sequence. If that limit is exceeded, an overspeed condition is detected by the system. In a second time period of the overall sequence, the counter is down counted by the pulse representations of speed. After the expiration of the second predetermined time period of the sequence, the counter value is compared to the original preset value to determine the rate of change in device speed. If the rate of change exceeds some preselected value, a low overspeed limit is used for the overspeed limit of the next up count for the subsequent sequence. If the rate of change does not exceed the preselected value, a high overspeed limit is used for the overspeed limit of the next up count for the subsequent sequence. The system outputs an overspeed signal only if an overspeed is detected on consecutive up count/down count portions of a sequence.
Inventors
- 👤 Raymond L. Hagrman
- 👤 Jack R. Sandridge
- 👤 Paul D. Soete
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:37
CPC Classifications
F; F01; F01D; F01D21/00; F01D21/02; G; G01; G01P; G01P1/00; G01P1/07; G01P1/08; G01P1/10; G01P1/103; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/489; G05; G05D; G05D13/00; G05D13/02; G05D13/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
89 words
A device for detecting an overspeed condition in an engine having at least one rotating part, comprising: means for sensing the rotational speed of the rotating part and developing an electrical signal based thereon; means for processing the speed signal including means for determining an overspeed indication when the part speed reaches a preselected high RPM value; and means for detecting an overspeed indication when the part speed reaches a lower but above normal RPM value and the rate of change of the RPM value exceeds a predetermined limit.
Claim 2
Independent Claim
89 words
A device for detecting an overspeed condition in an engine having at least one rotating part, comprising: means for sensing the rotational speed of the rotating part and developing an electrical signal based thereon; means for processing the speed signal including means for determining an overspeed indication when the part speed reaches a preselected high RPM value; and means for detecting an overspeed indication when the part speed reaches a lower but above normal RPM value and the rate of change of the RPM value exceeds a predetermined limit.
Claim 3
Dependent Claim
37 words
The device of claim 1 wherein said determining means comprises counter means caused to up count from a preset value for a predetermined period, and means for comparing the count of said counter with a preselected value.
Claim 4
Dependent Claim
48 words
The device of claim 2 wherein said detecting means comprises said counter means, wherein said counter means is caused to down count from the value obtained after said first period for a second period, and means for comparing the down count of said counter with said preset value.
Claim 5
Dependent Claim
30 words
The device of claim 3 further including means for checking operation of said device, said last-mentioned means including signal means for substituting a false speed signal to said processing means.
Claim 6
Dependent Claim
43 words
The device of claim 4 adapted for use in an aircraft, said aircraft including an engine employing engine electronic control means, further including output means for generating a signal to disable said engine electronic control upon the occurrence of an engine overspeed condition.
Claim 7
Dependent Claim
20 words
The device of claim 5 further including means for signalling an overspeed condition occurrence to a pilot of said aircraft.
Claim 8
Dependent Claim
18 words
The device of claim 6 further including means for visually indicating an overspeed condition occurrence at said device.
Claim 9
Dependent Claim
20 words
The device of claim 6 further including means for visually indicating a fault in said overspeed detector to said pilot.
Claim 10
Independent Claim
61 words
A method of detecting an overspeed occurrence on a rotating structure, comprising the steps of; obtaining a signal representation of the speed of said device; processing said signal representation to obtain an overspeed indication based on engine speed and on rate of change of engine speed; and developing an overspeed condition signal output upon the successive occurrence of said overspeed indication.
Claim 11
Independent Claim
61 words
A method of detecting an overspeed occurrence on a rotating structure, comprising the steps of; obtaining a signal representation of the speed of said device; processing said signal representation to obtain an overspeed indication based on engine speed and on rate of change of engine speed; and developing an overspeed condition signal output upon the successive occurrence of said overspeed indication.
Claim 12
Dependent Claim
47 words
The method of claim 9 wherein said process steps include the additional steps of: causing a counter means to up count from a preset value for a first time period; and comparing the count of said counter at the termination of said period with a preselected value.
Claim 13
Dependent Claim
45 words
The method of claim 10 further including the steps of: causing said counter means to down count from the value obtained after said first time period to the termination of a second time period; and comparing the count of said counter with said preset value.
Claim 14
Dependent Claim
15 words
The method of claim 10 wherein said first and said second time periods are equal.
Claim 15
Dependent Claim
93 words
In an avionics system for an aircraft employing an electronically activated control means for controlling an engine, the improvement comprising means for detecting a malfunction of the control means based on the speed of the engine controlled thereby, including means for developing a signal representation of engine speed, means for processing said engine speed representation so as to detect an overspeed indication based on engine speed and on rate of change in engine speed over a predetermined period, and means for disabling the control means upon the occurrence of two successive overspeed indications.
Claim 16
Dependent Claim
93 words
In an avionics system for an aircraft employing an electronically activated control means for controlling an engine, the improvement comprising means for detecting a malfunction of the control means based on the speed of the engine controlled thereby, including means for developing a signal representation of engine speed, means for processing said engine speed representation so as to detect an overspeed indication based on engine speed and on rate of change in engine speed over a predetermined period, and means for disabling the control means upon the occurrence of two successive overspeed indications.
Claim 17
Dependent Claim
37 words
The improvement of claim 13 wherein said processing means comprises counter means caused to up count from a preset value for a predetermined period, and means for comparing the count of said counter with a preselected value.
Claim 18
Dependent Claim
30 words
The improvement of claim 14 further including means for checking operation of said device, said last-mentioned means including signal means for substituting a false speed signal to said processing means.
Claim 19
Dependent Claim
43 words
The improvement of claim 15 adapted for use in an aircraft, said aircraft including an engine employing engine electronic control means, further including output means for generating a signal to disable said engine electronic control upon the occurrence of an engine overspeed condition.
Claim 20
Independent Claim
105 words
A system for detecting an overspeed condition in a device having at least one rotating part, comprises: means for sensing the rotational speed of the rotating part and developing an electrical signal based thereon; means for processing the speed signal including means for determining an overspeed indication when the part speed reaches a preselected high RPM value, and means for detecting an overspeed indication when the part speed reaches a lower but above normal RPM value and the rate of change of the RPM value exceeds a predetermined limit; and means for generating an overspeed condition signal upon the successive occurrence of said overspeed indications.
Claim 21
Independent Claim
105 words
A system for detecting an overspeed condition in a device having at least one rotating part, comprises: means for sensing the rotational speed of the rotating part and developing an electrical signal based thereon; means for processing the speed signal including means for determining an overspeed indication when the part speed reaches a preselected high RPM value, and means for detecting an overspeed indication when the part speed reaches a lower but above normal RPM value and the rate of change of the RPM value exceeds a predetermined limit; and means for generating an overspeed condition signal upon the successive occurrence of said overspeed indications.
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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) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |