US3900796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotational speed monitor
Assignee: Unisys Corp
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Filing: 1974-03-07
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Granted: 1975-08-19
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Expires: 1994-03-07
Abstract
Abstract A circuit is disclosed for monitoring the velocity of a rotating member and determining when its speed is below a predetermined value. The circuit arrangement is designed to compare the rotational speed of the member with an asynchronous AC line frequency. Signals produced by the circuitry are utilized for control purposes.
Inventors
- 👤 Andrew M Rose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:42
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/56; G01P3/60; G01P1/00; G01P1/07; G01P1/08; G01P1/10; G01P1/106
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
199 words
The method of monitoring the speed of a rotating member including the steps of a. sampling the number of revolutions of said rotating member within a first designated time period; b. sampling the number of cycles produced by an accurate frequency source with a second designated time period which is longer than said first time period, the cycles of said frequency source and the revolutions of said rotating member being asynchronous with respect to one another; c. generating a first control signal based on said first mentioned sampling when the number of preselected revolutions is not counted within said second designated time period, said first control signal causing a resampling of said number of revolutions and cycles; d. generating a second control signal based on said second mentioned sampling when the number of preselected revolutions is counted within said second designated time period, said second control signal indicating that a safe operating speed has been achieved; e. providing a third designated time period which is longer than second time period, whereby when said number of preselected revolutions is counted within said second designated time period, the number of preselected revolutions is thereafter counted within said third designated time period.
Claim 2
Independent Claim
199 words
The method of monitoring the speed of a rotating member including the steps of a. sampling the number of revolutions of said rotating member within a first designated time period; b. sampling the number of cycles produced by an accurate frequency source with a second designated time period which is longer than said first time period, the cycles of said frequency source and the revolutions of said rotating member being asynchronous with respect to one another; c. generating a first control signal based on said first mentioned sampling when the number of preselected revolutions is not counted within said second designated time period, said first control signal causing a resampling of said number of revolutions and cycles; d. generating a second control signal based on said second mentioned sampling when the number of preselected revolutions is counted within said second designated time period, said second control signal indicating that a safe operating speed has been achieved; e. providing a third designated time period which is longer than second time period, whereby when said number of preselected revolutions is counted within said second designated time period, the number of preselected revolutions is thereafter counted within said third designated time period.
Claim 3
Dependent Claim
36 words
The method in accordance with claim 1 and including the step of a. switching the time to said second period when the speed of the rotating member decreases to the count provided by said third period.
Claim 4
Dependent Claim
173 words
A rotational speed monitor comprising, a. first means for counting the number of revolutions produced by a rotating member and producing a first control signal when said means has counted a certain number of revolutions; b. second means for counting the number of pulses produced by an asynchronous frequency source wherein said means produces a second control signal after counting a number of cycles; c. reset means; d. means for transferring said first and second signals to said reset means whereby when said first means has counted a certain number of revolutions in a first prescribed time period, said first control signal will be directed to the reset means for clearing both said first and second counting means, and wherein said first means does not count said revolutions within said first designated time period, the reset means will be activated by said second control signal within a second designated time period which is longer than said first time period, said second control signal causing said first and second counting means to be cleared.
Claim 5
Dependent Claim
173 words
A rotational speed monitor comprising, a. first means for counting the number of revolutions produced by a rotating member and producing a first control signal when said means has counted a certain number of revolutions; b. second means for counting the number of pulses produced by an asynchronous frequency source wherein said means produces a second control signal after counting a number of cycles; c. reset means; d. means for transferring said first and second signals to said reset means whereby when said first means has counted a certain number of revolutions in a first prescribed time period, said first control signal will be directed to the reset means for clearing both said first and second counting means, and wherein said first means does not count said revolutions within said first designated time period, the reset means will be activated by said second control signal within a second designated time period which is longer than said first time period, said second control signal causing said first and second counting means to be cleared.
Claim 6
Dependent Claim
71 words
A rotational speed monitor in accordance with claim 3 and further comprising, a. means for providing a third designated period which is longer than said second time period and for producing a third control signal, whereby said signal reset means will be activated by said third control signal upon said rotating member reaching said second designated period, said third control signal causing said first and second counting means to be cleared.
Claim 7
Dependent Claim
20 words
A rotational speed motor in accordance with claim 3 wherein said frequency source is provided by an AC line frequency.
Claim 8
Dependent Claim
17 words
A rotational speed motor in accordance with claim 3 when said counting means comprise 4-bit ripple counters.
Claim 9
Dependent Claim
34 words
A rotational speed monitor in accordance with claim 4 wherein and including means for switching the time period to said second period when the speed of said rotating member decreases to said third period.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |