US4172252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monitoring arrangement for monitoring a change from a normal condition of any one of a plurality of condition sensing devices
Assignee: PREDICTOR SYSTEMS AB
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Filing: 1977-06-15
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Granted: 1979-10-23
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Expires: 1997-06-15
Abstract
Abstract A monitoring arrangement for monitoring a change from a normal condition of any one of a plurality of condition sensing devices. It includes a common two conductor circuit connecting the condition sensing devices. A central monitoring apparatus is connected to the common two conductor circuit and supplies current to the circuit. Each of the condition sensing devices includes a device for limiting the amount of current flowing therethrough from the common two conductor circuit; a mechanism to detect and to react to any change from a normal condition being sensed; and a mechanism to interrupt the current to at least all following condition sensing devices in the circuit upon reaction of the condition sensing device to a change in a condition being sensed. An apparatus is formed as part of the central monitoring apparatus for measuring and indicating a magnitude of current being supplied to the common two conductor circuit at any given time.
Inventors
- 👤 Leif Wiberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:05
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/018
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
151 words
A monitoring arrangement for monitoring a change from a normal condition of any one of a plurality of condition sensing devices including: a common two conductor circuit connecting said condition sensing devices, a central monitoring apparatus connected to said common two conductor circuit and supplying current to said circuit, each of said condition sensing devices including: (a) means to limit the amount of current flowing therethrough from said common two conductor circuit, (b) means to detect and react to any change from a normal condition being sensed, and (c) means to interrupt the current to at least all following condition sensing devices in said circuit upon reaction of the condition sensing device to a change in a condition being sensed, and means formed as a part of said central monitoring apparatus for measuring and indicating the magnitude of current being supplied to said common two conductor circuit at any given time.
Claim 2
Dependent Claim
151 words
A monitoring arrangement for monitoring a change from a normal condition of any one of a plurality of condition sensing devices including: a common two conductor circuit connecting said condition sensing devices, a central monitoring apparatus connected to said common two conductor circuit and supplying current to said circuit, each of said condition sensing devices including: (a) means to limit the amount of current flowing therethrough from said common two conductor circuit, (b) means to detect and react to any change from a normal condition being sensed, and (c) means to interrupt the current to at least all following condition sensing devices in said circuit upon reaction of the condition sensing device to a change in a condition being sensed, and means formed as a part of said central monitoring apparatus for measuring and indicating the magnitude of current being supplied to said common two conductor circuit at any given time.
Claim 3
Dependent Claim
33 words
The monitoring arrangement of claim 1 in which said means to limit the amount of current flowing through each condition sensing device limits the current to essentially equal values for each sensing device.
Claim 4
Dependent Claim
52 words
The monitoring arrangement of claim 1 in which said means to interrupt the current to at least all following condition sensing devices in said circuit includes a switch located in one conductor of said circuit with the switch movable between circuit closing and circuit interrupting positions by the operation of a relay.
Claim 5
Dependent Claim
31 words
The monitoring arrangement of claim 3 in which the operation of said relay is controlled by said means to detect and react to any change from a normal condition being sensed.
Claim 6
Dependent Claim
32 words
The monitoring arrangement of claim 4 in which said relay is magnetized when said means to detect and react to any change from a normal condition being sensed detects a normal condition.
Claim 7
Dependent Claim
32 words
The monitoring arrangement of claim 4 in which said relay is de-magnetized when said means to detect and react to any change from a normal condition being sensed detects a normal condition.
Claim 8
Dependent Claim
37 words
The monitoring arrangement of claim 6 in which said means to detect and react to any change from a normal condition being sensed changed its electrical resistance in response to a change in the condition being sensed.
References Cited (Backward Citations)
US3477019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |