Patent US3843848A successfully refreshed from Google Patents.
US3843848A
Expired / Lapsed
US
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Telephone looptest system
Assignee: Magnetic Controls Co
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Filing: 1973-01-12
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Granted: 1974-10-22
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Expires: 1993-01-12
Abstract
Abstract Apparatus is provided for remote testing of the condition of a telephone communication line to the point of interfacial connection between the line and customer equipment. The apparatus includes sensing means responsive to a trigger signal inserted onto the line at the telephone company end, the trigger signal being an alternating current tone burst of a given frequency, given minimum time duration, and given minimum voltage level. The sensed trigger signal activates a switch means at the point of customer interface, with the switch means in its quiescent, first condition maintaining the integrity of the line and in its second, activated condition disconnecting the line and inserting onto the line for a given period of time a given electrical impedance and a disconnect indicator. The sensing means is responsive to the presence of the trigger signal independent of the condition of any equipment beyond the point of customer interface when the switch means is in its first condition. Means for testing the condition of the telephone line with the given electrical impedance on the line are provided at the telephone company end of the line.
Inventors
- 👤 R Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:24
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/30; H04M3/301
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
197 words
In apparatus for remote testing of the condition of a telephone communication line which comprises a pair of conductors to the interface connection point to customer equipment in which apparatus there is an electrical impedance of given value at the interface connection point, switch means responsive to a trigger signal on the telephone communication line changeable in response to the trigger signal from a first condition in which the customer''s equipment is normally connected to the communication linE to a second condition in which the given electrical impedance is connected thereto for a given length of time, and means for testing the condition of the telephone line with a given electrical impedance connected thereto, the improvement comprising: means for applying an alternating current trigger signal to the line for at least a predetermined period of time; and inductive sensing means connected in series between a first and second section of one of the conductors responsive to the presence of the alternating current trigger signal for said predetermined period of time for operating the switch means independently of the condition of any equipment beyond the point of interface connection when the switch means is in its first condition.
Claim 2
Dependent Claim
197 words
In apparatus for remote testing of the condition of a telephone communication line which comprises a pair of conductors to the interface connection point to customer equipment in which apparatus there is an electrical impedance of given value at the interface connection point, switch means responsive to a trigger signal on the telephone communication line changeable in response to the trigger signal from a first condition in which the customer''s equipment is normally connected to the communication linE to a second condition in which the given electrical impedance is connected thereto for a given length of time, and means for testing the condition of the telephone line with a given electrical impedance connected thereto, the improvement comprising: means for applying an alternating current trigger signal to the line for at least a predetermined period of time; and inductive sensing means connected in series between a first and second section of one of the conductors responsive to the presence of the alternating current trigger signal for said predetermined period of time for operating the switch means independently of the condition of any equipment beyond the point of interface connection when the switch means is in its first condition.
Claim 3
Dependent Claim
45 words
The apparatus of claim 1 wherein the sensing means includes means responsive to the current flow in the line resulting from the application of said alternating current trigger signal to the line for changing the switch means from its first condition to its second condition.
Claim 4
Dependent Claim
64 words
The apparatus of claim 2 including: a capacitor between the conductors at a point between the inductive sensing means and the customer equipment; and an analyzing system responsive to the presence of current flow in said sensing means resulting from the application to the line of said alternating current trigger signal for changing the switch means from its first condition to its second condition.
Claim 5
Dependent Claim
103 words
The apparatus of claim 2 wherein the sensing means comprises: a first inductor means in series in at least one of the conductors; and further including a capacitor in series with a second inductor means, the combination of the capacitor and the second inductor means connected between the conductors at a location between the first inductor means and the customer equipment; and an analyzing system responsive to the presence of current flow in said first inductor means resulting from the application to the line of said alternating current trigger signal for changing the switch means from its first condition to its second condition.
Claim 6
Dependent Claim
41 words
The apparatus of claim 1 including analyzing means responsive to the voltage across the line resulting from the application of said alternating current trigger signal to the line for changing the switch means from its first condition to its second condition.
Claim 7
Dependent Claim
31 words
The apparatus of claim 5 wherein the sensing means further includes an inductor means in series in at least one of the lines between the analyzing system and the customer''s equipment.
Claim 8
Dependent Claim
43 words
The apparatus of claim 1 wherein the sensing means includes: a band pass amplifier responsive only to a trigger signal within a given frequency range; and a time delay circuit responsive only to a trigger signal of a greater than given time duration.
Claim 9
Dependent Claim
27 words
The apparatus of claim 1 further including a disconnect indicator for placing a given signal on the line while the switch means is in its second condition.
Claim 10
Dependent Claim
202 words
Apparatus for remote testing of the condition of a pair of telephone communication lines to the interface connection point to customer equipment comprising: switch means responsive to a trigger signal on the telephone communication lines movable in response to the trigger signal from a first condition in which the customer''s equipment is normally connected to the communication lines to a second condition; an electrical impedance of given value at the interface connection point; means operative when said switch means is in said second condition to connect said impedance across said telephone lines; means for testing the condition of the telephone lines with the electrical impedance connected thereto; means for applying an alternating current trigger signal to the lines for at least a predetermined time, and sensing means responsive to the presence of the alternating current trigger signal for operating the switch means, the sensing means including an inductor means in series in at least oNe of the lines, a capacitor across the lines at a point between the inductor means and the customer equipment, and an analyzing system including a band pass amplifier and a time delay circuit responsive to the presence of the alternating current trigger signal in the inductor means.
Claim 11
Dependent Claim
202 words
Apparatus for remote testing of the condition of a pair of telephone communication lines to the interface connection point to customer equipment comprising: switch means responsive to a trigger signal on the telephone communication lines movable in response to the trigger signal from a first condition in which the customer''s equipment is normally connected to the communication lines to a second condition; an electrical impedance of given value at the interface connection point; means operative when said switch means is in said second condition to connect said impedance across said telephone lines; means for testing the condition of the telephone lines with the electrical impedance connected thereto; means for applying an alternating current trigger signal to the lines for at least a predetermined time, and sensing means responsive to the presence of the alternating current trigger signal for operating the switch means, the sensing means including an inductor means in series in at least oNe of the lines, a capacitor across the lines at a point between the inductor means and the customer equipment, and an analyzing system including a band pass amplifier and a time delay circuit responsive to the presence of the alternating current trigger signal in the inductor means.
Claim 12
Dependent Claim
106 words
Apparatus for the remote testing of a telephone communication line comprising a pair of conductors up to the customer equipment connection comprising: means to apply an alternating current trigger signal to said line; an inductive pickup means in series in the circuit defined sequentially by one of said pair of conductors, the customer equipment, and the other of said pair of conductors at a point just before the customer equipment so as to detect the alternating current trigger signal; and switch means connected to said inductive pickup means responsive to the detection of said trigger signal to connect a known impedance across the pair of conductors.
Claim 13
Dependent Claim
106 words
Apparatus for the remote testing of a telephone communication line comprising a pair of conductors up to the customer equipment connection comprising: means to apply an alternating current trigger signal to said line; an inductive pickup means in series in the circuit defined sequentially by one of said pair of conductors, the customer equipment, and the other of said pair of conductors at a point just before the customer equipment so as to detect the alternating current trigger signal; and switch means connected to said inductive pickup means responsive to the detection of said trigger signal to connect a known impedance across the pair of conductors.
Claim 14
Dependent Claim
40 words
The apparatus of claim 10 in which said inductive pickup means comprises a pair of balanced inductors, one in each of the conductors, and a third inductor magnetically coupled to said balanced inductors and electrically connected to said switch means.
Claim 15
Dependent Claim
28 words
The apparatus of claim 11 including a capacitor connected across the pair of conductors containing the balanced inductors at a point between the inductors and the customer equipment.
Claim 16
Dependent Claim
55 words
The apparatus of claim 10 in which said inductive pickup means comprises: a first inductor means in series in at least one of said conductors; a capacitor in series with a second inductor means, the combination thereof connected between said pair of conductors at a point between the first inductor means and the customer equipment.
Claim 17
Dependent Claim
61 words
The apparatus of claim 10 wherein the inductive pickup means comprises an inductor in series in at least one of said conductors and voltage sensing means responsive to the voltage across the pair of lines resulting from said trigger signal, said voltage sensing means connected to said switch means so as to connect the known impedance to said pair of lines.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |