US4013839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for monitoring dialled telephone numbers
Assignee: TELSTOP SA
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Filing: 1974-11-08
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Granted: 1977-03-22
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Expires: 1994-11-08
Abstract
Abstract A system for monitoring dialled numbers is disclosed which provides a subscriber with a record of numbers dialled over his telephone line or lines. The system provides a monitoring unit inductively coupled to each line which tapes the dial pulses as they are dialled. Aslo included is a control processing unit which processes the individual tapes to provide a written record. The system thus eliminates the need for duplicating costly equipment such as discriminators and printers at each line.
Inventors
- 👤 Arthur Stewart Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:36
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/60; H04M3/64; H04M15/00; H04M15/04; H04M15/06; H04M15/10; H04M15/26
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
90 words
A system for monitoring numbers dialled over a telephone line the system comprising at least one recording means for sensing dial pulses representative of numbers dialled as well as pulses bearing no relationship to to said numbers dialled on a monitored telephone line and for recording each of the sensed pulses on a recording medium, and processing means for playing-back the recorded pulses on the recording medium, for analysing the pulses recorded thereon to determine the numbers dialled on the monitored line and for producing a display of numbers dialled.
Claim 2
Independent Claim
90 words
A system for monitoring numbers dialled over a telephone line the system comprising at least one recording means for sensing dial pulses representative of numbers dialled as well as pulses bearing no relationship to to said numbers dialled on a monitored telephone line and for recording each of the sensed pulses on a recording medium, and processing means for playing-back the recorded pulses on the recording medium, for analysing the pulses recorded thereon to determine the numbers dialled on the monitored line and for producing a display of numbers dialled.
Claim 3
Dependent Claim
13 words
A system according to claim 1 wherein the recording medium is magnetic tape.
Claim 4
Dependent Claim
16 words
A system according to claim 2 wherein the magnetic tape is contained in a standardized cassette.
Claim 5
Dependent Claim
16 words
A system according to claim 2 wherein the magnetic tape is contained in a standardized cartridge.
Claim 6
Dependent Claim
38 words
A system according to claim 1 wherein the recording means has a control circuit for starting the recording at the beginning of a call on the monitored line and for stopping the recording after dialling has been completed.
Claim 7
Dependent Claim
32 words
A system according to claim 5 wherein the control circuit includes a time-out circuit arranged to stop the recording when a predetermined period of time has elapsed after the last sensed pulse.
Claim 8
Dependent Claim
17 words
A system according to claim 6 wherein the predetermined period of time is at least ten seconds.
Claim 9
Dependent Claim
25 words
A system according to claim 1 wherein the recording means has a maximum recordable frequency which is in the lower part of the audio range.
Claim 10
Dependent Claim
23 words
A system according to claim 8 wherein the maximum recordable frequency is determined by the speed at which the recording medium is used.
Claim 11
Dependent Claim
17 words
A system according to claim 8 including a low pass filter to determine the maximum recordable frequency.
Claim 12
Dependent Claim
16 words
A system according to claim 8 wherein the maximum recordable frequency is 600 Hz or less.
Claim 13
Dependent Claim
46 words
A system according to claim 1 wherein the recording means is adapted only to record signals on its monitored telephone line which are above a predetermined threshold level lying in the range of 10dB to 30dB less than the level of dial pulses on the line.
Claim 14
Dependent Claim
23 words
A system according to claim 1 wherein the recording means includes an inductive pick-up for sensing dial pulses on the monitored telephone line.
Claim 15
Dependent Claim
33 words
A system according to claim 1 wherein the processing means includes play-back means adjusted to play-back the recording medium at a higher speed than the speed at which the dial pulses are recorded.
Claim 16
Dependent Claim
19 words
A system according to claim 14 wherein the said play-back speed is five or more times the recording speed.
Claim 17
Dependent Claim
56 words
A system according to claim 1 wherein the processing means includes a pulse discriminator and a counter, the discriminator being arranged to analyse the recorded pulses by determining the duration of recorded pulses and passing recorded pulses to the counter only if the recorded pulses are of a duration falling within acceptable tolerance for dial pulses.
Claim 18
Dependent Claim
48 words
A system according to claim 16 wherein the discriminator further includes means for determining the spacing of dial pulses and for passing pulses after the first pulse of any dialled digit to the counter only if they also arrive at time intervals with acceptable tolerances for dial pulses.
Claim 19
Dependent Claim
31 words
A system according to claim 1 wherein the processing means is arranged to ignore single pulses in any recorded number until after a digit of two or more pulses is detected.
Claim 20
Dependent Claim
54 words
A system according to claim 1 wherein said recording means includes a plurality of recording units for sensing said pulses on a plurality of respective monitored telephone lines and for recording each sensed pulse on a respective recording media, said processing unit playing back and analyzing the pulses on each of said recording media.
Claim 21
Dependent Claim
93 words
A recording unit for use in a system for monitoring numbers dialled over a monitored telephone line, the recording unit comprising: means for constraining a portion of the individual conductors of the telephone line in an untwisted state; an inductive pick-up for sensing signals in said portion of the monitored telephone line; recording means for recording pulses sensed by the pick-up; and an automatic control circuit for starting the recording means at the beginning of a call on the monitored telephone line and for stopping the recording means after dialling has been completed.
Claim 22
Dependent Claim
93 words
A recording unit for use in a system for monitoring numbers dialled over a monitored telephone line, the recording unit comprising: means for constraining a portion of the individual conductors of the telephone line in an untwisted state; an inductive pick-up for sensing signals in said portion of the monitored telephone line; recording means for recording pulses sensed by the pick-up; and an automatic control circuit for starting the recording means at the beginning of a call on the monitored telephone line and for stopping the recording means after dialling has been completed.
Claim 23
Dependent Claim
82 words
A processing unit for use in a system for monitoring numbers dialled over monitored telephone lines, the processing unit comprising play-back means for playing-back a recording medium on which pulses including dial pulses from the monitored telephone line have been recorded, a discriminator for accepting recorded pulses which fall within acceptable dial pulse tolerances, a counter for counting dial pulses accepted by the discriminator and an automatic printer responsive to the counter for displaying the numbers dialled over the monitored telephone lines.
Claim 24
Dependent Claim
82 words
A processing unit for use in a system for monitoring numbers dialled over monitored telephone lines, the processing unit comprising play-back means for playing-back a recording medium on which pulses including dial pulses from the monitored telephone line have been recorded, a discriminator for accepting recorded pulses which fall within acceptable dial pulse tolerances, a counter for counting dial pulses accepted by the discriminator and an automatic printer responsive to the counter for displaying the numbers dialled over the monitored telephone lines.
Claim 25
Independent Claim
93 words
A system for monitoring numbers dialled over a telephone line, the system comprising at least one recording unit for sensing dial pulses on a monitored telephone line and for recording the sensed pulses on a recording medium, a processing unit for playing-back the recording medium, analysing the recorded dial pulses and producing a display of numbers dialled, said recording unit including means for only recording signals on the monitored telephone line which are above a predetermined threshold level in the range of 10dB to 30dB less than the level of the dial pulses.
Claim 26
Independent Claim
93 words
A system for monitoring numbers dialled over a telephone line, the system comprising at least one recording unit for sensing dial pulses on a monitored telephone line and for recording the sensed pulses on a recording medium, a processing unit for playing-back the recording medium, analysing the recorded dial pulses and producing a display of numbers dialled, said recording unit including means for only recording signals on the monitored telephone line which are above a predetermined threshold level in the range of 10dB to 30dB less than the level of the dial pulses.
Claim 27
Independent Claim
82 words
A system for monitoring numbers dialled over a telephone line, the system comprising at least one recording unit for sensing dial pulses on a monitored telephone line and for recording the sensed pulses on a recording medium, and a processing unit for playing-back the recording medium, analysing the recorded dial pulses and producing a display of numbers dialled, said processing unit including means for ignoring single pulses in any recorded number until after a digit of two or more pulses is detected.
Claim 28
Independent Claim
82 words
A system for monitoring numbers dialled over a telephone line, the system comprising at least one recording unit for sensing dial pulses on a monitored telephone line and for recording the sensed pulses on a recording medium, and a processing unit for playing-back the recording medium, analysing the recorded dial pulses and producing a display of numbers dialled, said processing unit including means for ignoring single pulses in any recorded number until after a digit of two or more pulses is detected.
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) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |