US3778797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-station safety monitor having shunt switch
Assignee: PYOTT BOONE Inc
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Filing: 1972-07-10
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Granted: 1973-12-11
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Expires: 1992-07-10
Abstract
Abstract A device for monitoring a plurality of remote stations for disorders in which a high-impedance station line circuit is shunted by a disorder-responsive station switch with a distinctive lower resistance, whereupon a relay actuates an alarm and switches the station line circuit into an ohmmeter circuit. The storage-type digital ohmmeter indicates the location of the responding station; its readout is blocked after receipt of the first reading.
Inventors
- 👤 G Killen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:48
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/018
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
280 words
A multi-station monitoring device for detection of remote conditions comprising: a. a central monitoring unit, including a power source, b. a pair of station lines having a high resistance connected across one end and extending from said central unit to a plurality of remote locations and connected at the other end to said power source via two different connecting circuits in a central unit, c. said central unit including a first connecting circuit having a signal means therein, and a second connecting circuit having an ohmmeter therein, d. means for switching said pair of station lines from said first connecting circuit to said second connecting circuit including: 1. a first switching means being normally open and having means for closing same upon a current surge across said pair of station lines, 2. a second switching means controlled by the closing of said first switching means for electrically connecting said pair of station lines to said second connecting circuit, e. a monitoring station at each remote location, each monitoring station including at least one normally open condition responsive station switch and a station resistance of a distinctive resistance value, each of said distinctive resistance values being much less than the value of said high resistance, f. whereby said second switching means connects said pair of station lines to said first connecting circuit when all said station switches are open, the closing of one of said station switches causing a a current surge across said pair of station lines thus connecting said pair of station lines to said second connecting circuit and providing an indication on said ohmmeter commensurate with the value of the distinctive resistance value at the closed station switch.
Claim 2
Dependent Claim
280 words
A multi-station monitoring device for detection of remote conditions comprising: a. a central monitoring unit, including a power source, b. a pair of station lines having a high resistance connected across one end and extending from said central unit to a plurality of remote locations and connected at the other end to said power source via two different connecting circuits in a central unit, c. said central unit including a first connecting circuit having a signal means therein, and a second connecting circuit having an ohmmeter therein, d. means for switching said pair of station lines from said first connecting circuit to said second connecting circuit including: 1. a first switching means being normally open and having means for closing same upon a current surge across said pair of station lines, 2. a second switching means controlled by the closing of said first switching means for electrically connecting said pair of station lines to said second connecting circuit, e. a monitoring station at each remote location, each monitoring station including at least one normally open condition responsive station switch and a station resistance of a distinctive resistance value, each of said distinctive resistance values being much less than the value of said high resistance, f. whereby said second switching means connects said pair of station lines to said first connecting circuit when all said station switches are open, the closing of one of said station switches causing a a current surge across said pair of station lines thus connecting said pair of station lines to said second connecting circuit and providing an indication on said ohmmeter commensurate with the value of the distinctive resistance value at the closed station switch.
Claim 3
Dependent Claim
35 words
A device as defined in claim 1, including an alarm unit which is operated when said second switching means switches said pair of station lines from the first connecting circuit to the second connecting circuit.
Claim 4
Dependent Claim
148 words
a second switching means controlled by the closing of said first switching means for electrically connecting said pair of station lines to said second connecting circuit, e. a monitoring station at each remote location, each monitoring station including at least one normally open condition responsive station switch and a station resistance of a distinctive resistance value, each of said distinctive resistance values being much less than the value of said high resistance, f. whereby said second switching means connects said pair of station lines to said first connecting circuit when all said station switches are open, the closing of one of said station switches causing a a current surge across said pair of station lines thus connecting said pair of station lines to said second connecting circuit and providing an indication on said ohmmeter commensurate with the value of the distinctive resistance value at the closed station switch.
Claim 5
Dependent Claim
148 words
a second switching means controlled by the closing of said first switching means for electrically connecting said pair of station lines to said second connecting circuit, e. a monitoring station at each remote location, each monitoring station including at least one normally open condition responsive station switch and a station resistance of a distinctive resistance value, each of said distinctive resistance values being much less than the value of said high resistance, f. whereby said second switching means connects said pair of station lines to said first connecting circuit when all said station switches are open, the closing of one of said station switches causing a a current surge across said pair of station lines thus connecting said pair of station lines to said second connecting circuit and providing an indication on said ohmmeter commensurate with the value of the distinctive resistance value at the closed station switch.
Claim 6
Dependent Claim
41 words
A device as defined in claim 1, wherein the signal means in the first connecting circuit is a sensitive microammeter, and the end resistance on the station lines is correspondingly high to minimize power consumption when all station switches are open.
Claim 7
Dependent Claim
21 words
A device as defined in claim 1, wherein said first switching means in the first connecting circuit is a silicon-controlled rectifier.
Claim 8
Dependent Claim
33 words
A device as defined in claim 1, wherein the said pair of station lines lead to more than one type of disorder-responsive station switch, the different switches responding to different kinds of disorders.
Claim 9
Dependent Claim
21 words
A device as defined in claim 5, wherein two or more different disorder-responsive station switches are arranged at a single station.
Claim 10
Dependent Claim
23 words
A device as defined in claim 6, wherein the different switches in one station are arranged in parallel, controlling the same station resistance.
Claim 11
Dependent Claim
42 words
A device as defined in claim 7, wherein each station includes a distinct station resistance for each of its different disorder-responsive station switches, different kinds or levels of disorders thus giving a different readout on the ohmmeter in the second connecting circuit.
Claim 12
Dependent Claim
43 words
A device as defined in claim 1, wherein the ohmmeter in the second connecting circuit is of the storage type, and the second connecting circuit further includes means for disconnecting the ohmmeter from the station lines after receipt of a first resistance reading.
Claim 13
Dependent Claim
46 words
A device as defined in claim 9, wherein the ohmmeter is a storage-type digital ohmmeter and the distinctive resistance values of the several monitoring stations are chosen to give a numerical reading on the ohmmeter which is directly indicative of the relative locaTion of each station.
Claim 14
Dependent Claim
52 words
A device as defined in claim 9, wherein the disconnecting means includes a normally open single-throw relay separating the station lines from the second connecting circuit and a series-connected capacitor closing the single-throw relay for the duration of capacitor charging, which begins when the second switching means connects the second connecting circuit.
Claim 15
Dependent Claim
16 words
A device as defined in claim 1, wherein said second switching means is a double-throw relay.
References Cited (Backward Citations)
US2423649A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |