Patent US3597661A successfully refreshed from Google Patents.
US3597661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monitoring and shutdown apparatus
Assignee: Applied Automation Inc
•
Filing: 1970-03-13
•
Granted: 1971-08-03
•
Expires: 1990-03-13
Abstract
Abstract A control circuit for a monitoring device employs two timing elements of different durations. A signal from the monitor actuates the shorter duration-timing element, and the output from this timing elements actuates the longer duration timing element. An alarm or shutdown control is actuated if a second signal is received from the monitor during the timing interval of the longer duration-timing element.
Inventors
- 👤 Sherrill F Isaacs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:24
CPC Classifications
G; G08; G08B; G08B21/00; G08B21/18; G08B21/187
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
236 words
In a monitoring system which includes a transducer associated with a device to be monitored, said transducer establishing a first signal representative of a condition to be measured, and a control element associated with the device to be monitored; control apparatus comprising: actuating means to actuate said control element when current is supplied to said actuating means; a source of current; first, second and third switching means; circuit means connecting said first switching means, said actuating means, and said second switching means in circuit with said source of current so that said actuating means receives current when said first and second switching means are actuated; first timing means to establish a second signal a first predetermined time interval after said first timing means is actuated; second timing means to establish a third signal a second predetermined time interval after said first timing means is actuated, said second time interval being longer than said first time interval; means responsive to said transducer to actuate said third switching means when said first signal exceeds a threshold value; means responsive to said third switching means being actuated to actuate said first timing means and said first switching means; means responsive to said second signal to deactuate said first switching means, actuate said second switching means, actuate said second timing means, and deactuate said third switching means; and means responsive to said third signal to deactuate said second switching means.
Claim 2
Dependent Claim
236 words
In a monitoring system which includes a transducer associated with a device to be monitored, said transducer establishing a first signal representative of a condition to be measured, and a control element associated with the device to be monitored; control apparatus comprising: actuating means to actuate said control element when current is supplied to said actuating means; a source of current; first, second and third switching means; circuit means connecting said first switching means, said actuating means, and said second switching means in circuit with said source of current so that said actuating means receives current when said first and second switching means are actuated; first timing means to establish a second signal a first predetermined time interval after said first timing means is actuated; second timing means to establish a third signal a second predetermined time interval after said first timing means is actuated, said second time interval being longer than said first time interval; means responsive to said transducer to actuate said third switching means when said first signal exceeds a threshold value; means responsive to said third switching means being actuated to actuate said first timing means and said first switching means; means responsive to said second signal to deactuate said first switching means, actuate said second switching means, actuate said second timing means, and deactuate said third switching means; and means responsive to said third signal to deactuate said second switching means.
Claim 3
Dependent Claim
69 words
The apparatus of claim 1 wherein each of said timing means comprises a unijunction transistor, a capacitor connected to the base of said unijunction transistor, and a resistor connected to said capacitor and said base so that current flow through said resistor charges said capacitor to a voltage sufficiently high to fire said unijunction transistor, the firing of said unijunction transistor establishing an output signal from the timing means.
Claim 4
Dependent Claim
77 words
The apparatus of claim 1 wherein said third and first switching means are connected in series between one terminal of said current source and said actuating means, said second switching means comprises a transistor and said third switching means comprises a switch having a relay coil associated therewith which serves to open the switch when current is applied to the relay coil, and wherein said means responsive to said second signal applies current to said relay coil.
Claim 5
Dependent Claim
40 words
The apparatus of claim 3 wherein said means to apply current to said relay coil comprises a silicon controlled rectifier, and wherein said second signal is applied to the gate electrode of said rectifier to cause said rectifier to conduct.
Claim 6
Dependent Claim
43 words
The apparatus of claim 1 wherein said second switching means is a transistor and wherein said means to actuate said second switching means comprises a silicon controlled rectifier, said means responsive to said third signal serving to block current flow through said rectifier.
References Cited (Backward Citations)
US3170689A
Cited
US3441808A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |