Patent US4061445A successfully refreshed from Google Patents.
US4323733A
Expired / Lapsed
US
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Range extender with variable gain for coin telephone loops
Assignee: AT&T Inc
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Filing: 1980-11-28
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Granted: 1982-04-06
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Expires: 2000-11-28
Abstract
Abstract A range extender with gain unit for coin telephone loops is disclosed. When coin control signals to be applied from a central office to the coin loop are detected, an amplifier circuit and a line feed circuit connected to the loop are disconnected thereby directly connecting the central office with the coin telephone. After coin control is completed, the amplifier and line feed circuit are reinserted into the coin loop. Coin tests and off-hook detection are aided by the use of circuits which draw current from the central office.
Inventors
- 👤 Henry W. Ott
- 👤 Bernard A. Tilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:00
CPC Classifications
H; H04; H04M; H04M17/00; H04M17/02; H04M17/023
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
68 words
A method of controlling a coin telephone from a central office over a coin subscriber loop characterized by the steps of detecting the flow of current through a single conductor in said coin subscriber loop, detecting the absence of coin control signal voltages, and in response to said current and voltage detection, inserting an amplifier circuit (100) and a line feed circuit (52) into said coin subscriber loop.
Claim 2
Independent Claim
68 words
A method of controlling a coin telephone from a central office over a coin subscriber loop characterized by the steps of detecting the flow of current through a single conductor in said coin subscriber loop, detecting the absence of coin control signal voltages, and in response to said current and voltage detection, inserting an amplifier circuit (100) and a line feed circuit (52) into said coin subscriber loop.
Claim 3
Dependent Claim
51 words
The method of controlling the coin telephone according to claim 1 further characterized by the steps of detecting the application of said coin control signals from said central office, and directly connecting said central office with said coin telephone, thereby bypassing said amplifier circuit (100) and said line feed circuit (52).
Claim 4
Dependent Claim
33 words
The method of controlling the coin telephone according to claim 1 further characterized by the step of relaying polarity reversals from said central office around said amplifier circuit (100) to said coin telephone.
Claim 5
Dependent Claim
49 words
The method of controlling the coin telephone according to claim 1 further characterized by the step of aiding said central office in detecting the state of said coin telephone by drawing current from said central office for either the loop-start or the ground-start method of detection of call origination.
Claim 6
Independent Claim
67 words
A method of controlling a coin telephone from a central office over a coin subscriber loop characterized by the steps of detecting the removal of current from said central office to said coin loop, disconnecting an amplifier circuit (100) and a line feed circuit (52) from said coin loop in response to said removal of current, and simultaneously directly connecting said central office with said coin loop.
Claim 7
Independent Claim
67 words
A method of controlling a coin telephone from a central office over a coin subscriber loop characterized by the steps of detecting the removal of current from said central office to said coin loop, disconnecting an amplifier circuit (100) and a line feed circuit (52) from said coin loop in response to said removal of current, and simultaneously directly connecting said central office with said coin loop.
Claim 8
Dependent Claim
41 words
The method of controlling the coin telephone according to claim 5 further characterized by the step of drawing current from said central office in response to coin test voltages to enable detection of the presence of coins in said coin telephone.
Claim 9
Dependent Claim
102 words
Apparatus for range extension of direct current supervisory signals and for providing gain for voice frequency signals for a telephone subscriber loop connecting a central office with a coin telephone characterized by means (18) for detecting current flow through one conductor (13,17) in said loop in response to a change in state of said coin telephone, means (22) for detecting the absence of coin control signals transmitted from said central office to said coin telephone, and means (20) responsive to said current and control signal detecting means for connecting an amplifier circuit (100) and a line feed circuit (52) with said loop.
Claim 10
Dependent Claim
102 words
Apparatus for range extension of direct current supervisory signals and for providing gain for voice frequency signals for a telephone subscriber loop connecting a central office with a coin telephone characterized by means (18) for detecting current flow through one conductor (13,17) in said loop in response to a change in state of said coin telephone, means (22) for detecting the absence of coin control signals transmitted from said central office to said coin telephone, and means (20) responsive to said current and control signal detecting means for connecting an amplifier circuit (100) and a line feed circuit (52) with said loop.
Claim 11
Dependent Claim
33 words
The apparatus according to claim 7 further characterized by means responsive to said current and voltage detecting means for connecting a grounded resistor (42) with a conductor (11 or 13) in said loop.
Claim 12
Dependent Claim
23 words
The apparatus according to claim 7 further characterized by means (26,34) for relaying dial pulses from said coin telephone to said central office.
Claim 13
Dependent Claim
39 words
The apparatus according to claim 7 further characterized by means (88,20) for determining whether a coin test should be performed on a ring conductor (13) or on a tip conductor (11), and means (42,74) for aiding said coin test.
Claim 14
Dependent Claim
59 words
A coin range extender with gain for coin telephone loops, said range extender including means (18,20) responsive to current in said loop for inserting a voice frequency gain device (58) into said loop, said extender characterized by means (22,54) for detecting coin control voltages, and means (20) responsive to said detecting means for removing said device from said loop.
Claim 15
Dependent Claim
59 words
A coin range extender with gain for coin telephone loops, said range extender including means (18,20) responsive to current in said loop for inserting a voice frequency gain device (58) into said loop, said extender characterized by means (22,54) for detecting coin control voltages, and means (20) responsive to said detecting means for removing said device from said loop.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-05 | 1985-10-05 | 1986-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-05 | 1989-10-05 | 1990-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-05 | 1993-10-05 | 1994-04-06 | $7700.00 | Window Closed / Lapsed |