Patent US4975970A successfully refreshed from Google Patents.
US3585477A
Expired / Lapsed
US
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Motor speed control device including fail safe monitor
Assignee: Bendix Corp
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Filing: 1968-12-16
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Granted: 1971-06-15
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Expires: 1988-12-16
Abstract
Abstract A monitor for motor speed control apparatus, and which apparatus affects control by applying pulses of varying frequency to the motor. If the controlling output is a steady state output or if there is an interval monitor failure, a relay is affected for actuating an alarm.
Inventors
- 👤 George A Shacknow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:55
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34; G01R31/343; H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833; H02H7/0844; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/909
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
177 words
For a system including a motor, a motor speed control means in combination with a monitor, comprising: a pulse source for providing pulses of varying frequency and including means for effecting said pulses so that they have a constant on time and a varying off time; means connected to the pulse source for shaping the pulses therefrom; the motor connected to the pulse shaping means so that the speed of the motor corresponds to the frequency of the pulses therefrom; the monitor connected to the pulse shaping means for detecting a loss of said pulses and for thereupon activating an alarm, said monitor including; a resistor, a first current flow control device, a first capacitor and switching means connected in parallel with the pulse shaping means; a second capacitor connected in series with the pulse shaping means and connected intermediate the resistor and the first current flow control device; and a second current flow control device connected in series with the pulse shaping means and connected intermediate the first current flow control device and the first capacitor.
Claim 2
Dependent Claim
177 words
For a system including a motor, a motor speed control means in combination with a monitor, comprising: a pulse source for providing pulses of varying frequency and including means for effecting said pulses so that they have a constant on time and a varying off time; means connected to the pulse source for shaping the pulses therefrom; the motor connected to the pulse shaping means so that the speed of the motor corresponds to the frequency of the pulses therefrom; the monitor connected to the pulse shaping means for detecting a loss of said pulses and for thereupon activating an alarm, said monitor including; a resistor, a first current flow control device, a first capacitor and switching means connected in parallel with the pulse shaping means; a second capacitor connected in series with the pulse shaping means and connected intermediate the resistor and the first current flow control device; and a second current flow control device connected in series with the pulse shaping means and connected intermediate the first current flow control device and the first capacitor.
Claim 3
Dependent Claim
70 words
Apparatus as described by claim 1 wherein: the first current flow control device is conductive during the on time of the pulses from the pulse shaping means for providing a path for the second capacitor to charge; and the second capacitor discharges during the off time of said pulses causing the first capacitor to charge through the second current flow control device and the load of the pulse shaping means.
Claim 4
Dependent Claim
35 words
Apparatus as described by claim 2, wherein: the switching means is energized by the voltage across the first capacitor; and a loss of said voltage causing the switching means to deenergize for activating the alarm.
Claim 5
Dependent Claim
39 words
Apparatus as described by claim 3, wherein: the second current flow control device is effective for isolating the first capacitor and the switching means so that the only discharge path for said first capacitor is through the switching means.
Claim 6
Dependent Claim
42 words
Apparatus as described by claim 4, wherein: a steady state output provided by the pulse shaping means is blocked by the second capacitor causing the first capacitor to discharge through the switching means for deenergizing the switching means to actuate the alarm.
Claim 7
Dependent Claim
35 words
Apparatus as described by claim 5, wherein: a zero output provided by the pulse shaping means causes the first capacitor to dischargE through the switching means for deenergizing the switching means to actuate the alarm.
Claim 8
Dependent Claim
52 words
Apparatus as described by claim 2, wherein: a failure in the second capacitor renders said second capacitor ineffective for storing a charge and for discharging to the first capacitor during the off time of the pulses from the pulse shaping means, whereupon the first capacitor will not charge during said off time.
Claim 9
Dependent Claim
45 words
Apparatus as described by claim 6, wherein: an open second current flow control device destroys the discharge path from the second capacitor to the first capacitor; and a shorted second current flow control device destroys the isolation of the first capacitor and the switching means.
Claim 10
Dependent Claim
31 words
Apparatus as described by claim 2, wherein: an open first diode prevents the second capacitor from charging; and a shorted first diode causes the second capacitor to discharge through the short.
Claim 11
Dependent Claim
34 words
Apparatus as described by claim 9, including: said resistor being open destroying the discharge path from the second capacitor to the first capacitor; and said resistor being shorted providing zero input to the monitor.
Claim 12
Dependent Claim
27 words
Apparatus as described by claim 2, wherein: a failure in the first capacitor renders said capacitor ineffective for storing a charge whereupon the switching means is deenergized.
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) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |