US3848241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test and integrity equipment for a mcculloh system
Assignee: Baker Industries Inc
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Filing: 1973-03-15
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Granted: 1974-11-12
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Expires: 1993-03-15
Abstract
Abstract An interrogation unit is connected between the feed and return line of a McCulloh alarm circuit (i.e. between a McCulloh receiver and a plurality of McCulloh transmitter) to maintain the line current relatively constant and not disturb or interfere with the basic McCulloh alarm function. The interrogation unit transmits a command signal to receive units which are serially connected with selected McCulloh transmitters in the basic McCulloh circuit. The command signal is a pulse having a polarity opposite that of the normal McCulloh alarm signal. During the command pulse time period, the McCulloh receiver is disconnected from the telephone line and connected to a circuit that maintains the previous current flowing into the McCulloh receiver. This provides substantially no interference with the normal alarm function of the McCulloh circuit. Each McCulloh transmitter initiates a reply pulse. Each reply pulse, which is at a magnitude much lower than the normal McCulloh alarm signal, provides information such as line integrity and alarm ''''set'''' information. The reply pulse level is sufficiently low to assure that there is no interference with normal McCulloh alarm signals.
Inventors
- 👤 T Lenay
- 👤 D Hadden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:01
CPC Classifications
G; G08; G08B; G08B29/00; G08B29/02; G08B29/12
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
160 words
In a McCulloh circuit having a feed line and a return line including a DC voltage source powering a McCulloh receiver at a central station and a plurality of McCulloh transmitters with their associated set contacts located at subscriber locations, a test system therefore comprising; an interrogation means releasably connected at the central station in the feed line and the return line to maintain the normal current in the McCulloh circuit when connected therein, said interrogation means including means for generating a command signal of the opposite polarity of a McCulloh alarm signal and means for receiving a reply signal; and a plurality of receiver units, each of said receiver units connected in series with a McCulloh transmitter and its associated set contacts at various subscriber locations, each of said receiver units including means for receiving the command signal and means for sequentially responding with a reply signal to said interrogation means without interfering with reception of McCulloh alarm signals.
Claim 2
Dependent Claim
160 words
In a McCulloh circuit having a feed line and a return line including a DC voltage source powering a McCulloh receiver at a central station and a plurality of McCulloh transmitters with their associated set contacts located at subscriber locations, a test system therefore comprising; an interrogation means releasably connected at the central station in the feed line and the return line to maintain the normal current in the McCulloh circuit when connected therein, said interrogation means including means for generating a command signal of the opposite polarity of a McCulloh alarm signal and means for receiving a reply signal; and a plurality of receiver units, each of said receiver units connected in series with a McCulloh transmitter and its associated set contacts at various subscriber locations, each of said receiver units including means for receiving the command signal and means for sequentially responding with a reply signal to said interrogation means without interfering with reception of McCulloh alarm signals.
Claim 3
Dependent Claim
29 words
The system as in claim 1 wherein said means for receiving the reply signal includes a first sense amplifier electrically connected in the return line of the McCulloh circuit.
Claim 4
Dependent Claim
7 words
charging storage means to a predetermined level;
Claim 5
Dependent Claim
7 words
charging storage means to a predetermined level;
Claim 6
Dependent Claim
34 words
connecting an interrogation unit to the feed and return line of the McCulloh circuit when the storage means reaches the predetermined level to maintain the current in the McCulloh circuit at a constant level;
Claim 7
Dependent Claim
34 words
connecting an interrogation unit to the feed and return line of the McCulloh circuit when the storage means reaches the predetermined level to maintain the current in the McCulloh circuit at a constant level;
Claim 8
Dependent Claim
38 words
The system as in claim 2 including a clamp circuit wherein said clamp circuit is electrically connected to said first and second sense amplifiers to reset said first and second sense amplifiers between replies from said receiver units.
Claim 9
Dependent Claim
22 words
The system as in claim 1 wherein said interrogation means is capable of being sequentially connected to a plurality of McCulloh circuits.
Claim 10
Dependent Claim
34 words
transmitting a command signal of the opposite polarity of a McCulloh alarm signal from the interrogation unit to a plurality of receiver units associated with McCulloh transmitters and set contacts at various subscriber locations;
Claim 11
Dependent Claim
34 words
transmitting a command signal of the opposite polarity of a McCulloh alarm signal from the interrogation unit to a plurality of receiver units associated with McCulloh transmitters and set contacts at various subscriber locations;
Claim 12
Dependent Claim
10 words
receiving the command signal at the plurality of receiver units;
Claim 13
Dependent Claim
10 words
receiving the command signal at the plurality of receiver units;
Claim 14
Dependent Claim
38 words
The system as in claim 1 wherein said means for generating a command signal provides separate reception of reply signals on the feed line and on the return line in order to determine the location of a fault.
Claim 15
Dependent Claim
31 words
transmitting a reply signal sequentially from each receiver unit to the interrogation unit, the reply signal being of a magnitude so chosen to prevent interference with the McCulloh alarm signal; and
Claim 16
Dependent Claim
31 words
transmitting a reply signal sequentially from each receiver unit to the interrogation unit, the reply signal being of a magnitude so chosen to prevent interference with the McCulloh alarm signal; and
Claim 17
Dependent Claim
47 words
The system as in claim 1 wherein said means for generating a command signal also is capable of generating a second command signal longer in duration than the command signal, said second command signal being sensed in said selected receiver unit thereby remotely causing a test therein.
Claim 18
Dependent Claim
39 words
receiving the reply signal at the interrogation unit at its central station, the reply signal containing at least one pulse, the reply signal containing information as to line integrity and the set condition of the set contacts associated therewith.
Claim 19
Dependent Claim
39 words
receiving the reply signal at the interrogation unit at its central station, the reply signal containing at least one pulse, the reply signal containing information as to line integrity and the set condition of the set contacts associated therewith.
Claim 20
Dependent Claim
28 words
The system as in claim 6 wherein the McCulloh transmitter is connected to the selected receiver unit being tested and is prevented from being activated by the test.
Claim 21
Dependent Claim
43 words
The system as in claim 1 wherein said means for receiving the reply signal includes a first sense amplifier electrically connected in the return line of the McCulloh circuit, thereby allowing system operation in the presence of a single fault on the line.
Claim 22
Independent Claim
51 words
A method for testing equipment on a McCulloh circuit having a feed line and a return line without interference with the McCulloh alarm signal including a McCulloh receiver at a central station and a plurality of McCulloh transmitters with their associated set contacts located at subscriber locations, comprising the steps of:
Claim 23
Independent Claim
51 words
A method for testing equipment on a McCulloh circuit having a feed line and a return line without interference with the McCulloh alarm signal including a McCulloh receiver at a central station and a plurality of McCulloh transmitters with their associated set contacts located at subscriber locations, comprising the steps of:
Claim 24
Dependent Claim
19 words
The method of claim 9 wherein said system operates in the presence of a single fault on the line.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |