Patent EP0592091A2 successfully refreshed from Google Patents.
Patent US3699274A successfully refreshed from Google Patents.
US3699274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for identifying telephone cable pairs
Assignee: Perkins Res & Manufacturing Co
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Filing: 1971-07-22
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Granted: 1972-10-17
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Expires: 1991-07-22
Abstract
Abstract An apparatus for identifying telephone cable pairs which may be in use by the customer without disturbing service, including a tone source, a simplex device and a switch circuit working in conjunction with the simplex device using the pair capacity to operate the circuit only when the proper electrical connection is made between the tapping wires of the device and each of the pair wires.
Inventors
- 👤 Richard L Bennett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:40
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/50; G01R31/58; G01R31/60
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
An apparatus for identifying telephone cable pairs which may be in use by the customer without disturbing user service comprising: a simplex device; a tone source; a pair of tapping leads for electrically connecting said simplex device and tone source to the telephone pair; and capacity responsive switch circuit means for permitting application of the simplexed tone to the pair only when both of said pair of tapping leads are electrically connected to the telephone pair.
Claim 2
Independent Claim
76 words
An apparatus for identifying telephone cable pairs which may be in use by the customer without disturbing user service comprising: a simplex device; a tone source; a pair of tapping leads for electrically connecting said simplex device and tone source to the telephone pair; and capacity responsive switch circuit means for permitting application of the simplexed tone to the pair only when both of said pair of tapping leads are electrically connected to the telephone pair.
Claim 3
Dependent Claim
109 words
The apparatus of claim 1 wherein said switch circuit means comprises: a source of electrical power; an oscillator providing a signal having a frequency above the audible range; a transformer having a primary winding connected to said oscillator and to said other tapping lead; a relay switch connected to the secondary winding of said transformer; and a transistor switch circuit connected between said relay switch and said secondary winding for controlling said relay switch, whereby the telephone pair capacitance completes the circuit means to operate the relay and permit application of the tone to the pair only when both of the tapping leads are electrically connected to the pair.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2 wherein said transformer is tunable and connected in parallel with a capacitor.
Claim 5
Dependent Claim
16 words
The apparatus of claim 2 wherein said oscillator is coupled to said circuit through a transformer.
Claim 6
Dependent Claim
19 words
The apparatus of claim 2 wherein said transformer is connected to the other tapping lead through a blocking capacitor.
Claim 7
Dependent Claim
49 words
The apparatus of claim 2 wherein said transistor switch circuit includes a variable resistance for biasing one transistor to control the on/off level of said switch such that the capacitance load of at least a 50 foot length of telephone pair wires will cause the switch to turn on.
Claim 8
Dependent Claim
27 words
The apparatus of claim 6 wherein the switch level is such that the resistance load of a person''s body will not cause the switch to turn on.
Claim 9
Dependent Claim
18 words
The apparatus of claim 1 wherein said tone source produces an audible tone of approximately 500 cycle frequency.
Claim 10
Dependent Claim
88 words
In an apparatus for identifying telephone cable pairs which may be in use by the customer without producing an audible signal on the pair comprising a signal source, a simplex device, a pair of manually attachable tapping leads for electrical connection of the apparatus to the telephone pair, the improvement comprising, a capacity responsive switch circuit for permitting a signal to be sent on the pair only when both tapping leads are electrically connected to the pair wires so that the capacitance of the pair provides a load.
Claim 11
Dependent Claim
88 words
In an apparatus for identifying telephone cable pairs which may be in use by the customer without producing an audible signal on the pair comprising a signal source, a simplex device, a pair of manually attachable tapping leads for electrical connection of the apparatus to the telephone pair, the improvement comprising, a capacity responsive switch circuit for permitting a signal to be sent on the pair only when both tapping leads are electrically connected to the pair wires so that the capacitance of the pair provides a load.
Claim 12
Dependent Claim
22 words
The improvement of claim 9 wherein said switch circuit includes an oscillator producing a signal having a frequency above the audible range.
References Cited (Backward Citations)
US3536864A
Cited
US3581008A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |