Patent US4375014A successfully refreshed from Google Patents.
US4375014A
Expired / Lapsed
US
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Current sensing trigger for a telephone system
Assignee: GREAT LAKES COMMUNICATION Co
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Filing: 1981-02-17
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Granted: 1983-02-22
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Expires: 2001-02-17
Abstract
Abstract In a loop closure seizure step-by-step telephone system, a pulsing circuit is provided comprising a current sensing trigger having first and second semiconductor barrier elements disposed in a series circuit relationship for receiving dial pulses generated by a first subscriber telephone set. The dial pulses establish a current through the first and second semiconductor barrier elements and a circuit is provided for sensing a trigger voltage established between first and second semiconductor barrier elements. A circuit is also provided for amplifying this trigger voltage and operating a stepping switch to interconnect the first subscriber telephone set and a second subscriber telephone set pursuant to a number dialed on the first subscriber telephone set.
Inventors
- 👤 Allen C. Horak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:19
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/32
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
142 words
A loop closure seizure step-by-step telephone system comprising: a first subscriber telephone set; a central switching station; means for interconnecting said first subscriber telephone set and said central switching station; a stepping switch for connecting said first subscriber telephone set to a second subscriber telephone set; means for generating dial pulses representative of a number being dialed on said first subscriber telephone set; first and second semiconductor barrier means disposed in a series circuit relationship for receiving said dial pulses, said dial pulses establishing current therethrough; means for sensing a trigger voltage between said first and second semiconductor barrier means when a current is established therethrough; and means for amplifying said trigger voltage and operating said stepping switch to connect said first subscriber telephone set and a second subscriber telephone set pursuant to a number dialed on said first subscriber telephone set.
Claim 2
Dependent Claim
142 words
A loop closure seizure step-by-step telephone system comprising: a first subscriber telephone set; a central switching station; means for interconnecting said first subscriber telephone set and said central switching station; a stepping switch for connecting said first subscriber telephone set to a second subscriber telephone set; means for generating dial pulses representative of a number being dialed on said first subscriber telephone set; first and second semiconductor barrier means disposed in a series circuit relationship for receiving said dial pulses, said dial pulses establishing current therethrough; means for sensing a trigger voltage between said first and second semiconductor barrier means when a current is established therethrough; and means for amplifying said trigger voltage and operating said stepping switch to connect said first subscriber telephone set and a second subscriber telephone set pursuant to a number dialed on said first subscriber telephone set.
Claim 3
Dependent Claim
47 words
The telephone system of claim 1 wherein said first and second semiconductor barrier means comprise a transistor trigger having a base, a collector and an emitter, said dial pulses being applied such that a current is established through said collector and said emitter of said transistor trigger.
Claim 4
Dependent Claim
22 words
The telephone system of claim 2 wherein said transistor trigger comprises an NPN transistor that is forward biased by said dial pulses.
Claim 5
Dependent Claim
21 words
The telephone system of claim 3 wherein said means for sensing a trigger voltage comprises said base of said transistor trigger.
Claim 6
Dependent Claim
20 words
The telephone system of claim 1 wherein said first and second semiconductor barrier means are first and second trigger diodes.
Claim 7
Dependent Claim
37 words
The telephone system of claim 5 wherein said first and second trigger diods and said means for generating dial pulses are connected such that said first and second trigger diodes are forward biased by said dial pulses.
Claim 8
Dependent Claim
52 words
The telephone system of claim 1 wherein said means for amplifying said trigger voltage and operating said stepping switch comprises: a normally closed first switching means for applying power to said stepping switch; and a normally open second switching means for isolating an enabling relay, for enabling operation of said stepping switch.
Claim 9
Dependent Claim
53 words
The telephone system of claim 7 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises means for opening said first switching means and closing said second switching means, when a trigger voltage is sensed, to isolate said stepping switch and apply power to said enabling relay, respectively.
Claim 10
Dependent Claim
49 words
The telephone system of claim 8 wherein said normally closed first switching means and said normally open second switching means are both connected to ground for alternately connecting ground to electrical circuits containing said stepping switch and said enabling relay, respectively, whereby a set of break/make contacts are simulated.
Claim 11
Dependent Claim
61 words
The telephone system of claim 8 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a normally open third switching means for isolating a second relay, said means for opening said first switching means and closing said second switching means further comprising means for closing said third switching means when a trigger voltage is sensed.
Claim 12
Dependent Claim
63 words
The telephone sytem of claim 1 wherein said means for amplifying said trigger voltage and operating said stepping switch comprises a forward biased PNP first amplifier transistor having a base, emitter and collector, said base of said first transistor being connected to said means for sensing a trigger voltage such that said first transistor is switched on when a trigger voltage is sensed.
Claim 13
Dependent Claim
67 words
The telephone system of claim 11 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a forward biased PNP second amplifier transistor having a base, emitter and collector, said base and said emitter of said second transistor being connected to said collector and said emitter of said first transistor for switching said second transistor off when a trigger voltage is sensed.
Claim 14
Dependent Claim
61 words
The telephone system of claim 12 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a forward biased PNP third amplifier transistor having a base, emitter and collector, said base of said third transistor being connected to said emitter of said second transistor for switching said third transistor off when a trigger voltage is sensed.
Claim 15
Dependent Claim
53 words
The telephone system of claim 13 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises: a normally closed first switching means for applying power to said stepping switch; and a normally open second switching means for isolating an enabling relay, for enabling operation of said stepping switch.
Claim 16
Dependent Claim
47 words
The telephone system of claim 14 wherein said first, second and third amplifier transistors comprise means for opening said first switching means and closing said second switching means, when a trigger voltage is sensed, to isolate said stepping switch and apply power to said enabling relay, respectively.
Claim 17
Dependent Claim
49 words
The telephone system of claim 15 wherein said normally closed first switching means and said normally open second switching means are both connected to ground for alternately connecting ground to electrical circuits containing said stepping switch and said enabling relay, respectively, whereby a set of break/make contacts are simulated.
Claim 18
Dependent Claim
54 words
The telephone system of claim 16 wherein said normally closed first switching means comprises a forward biased NPN fourth amplifier transistor having a base, emitter and collector, said base of said fourth transistor being connected to said collector of said third transistor for switching said fourth transistor off when a trigger voltage is sensed.
Claim 19
Dependent Claim
54 words
The telephone system of claim 17 wherein said normally open second switching means comprises a forward biased PNP fifth amplifier transistor having a base, emitter and collector, said base of said fifth transistor being connected to said collector of said second transistor for switching said fifth transistor on when a trigger voltage is sensed.
Claim 20
Dependent Claim
53 words
The telephone system of claim 18 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a normally open third switching means for isolating a second relay, said first, second and third amplifier transistors comprising means for closing said third switching means when a trigger voltage is sensed.
Claim 21
Dependent Claim
54 words
The telephone system of claim 19 wherein said normally open third switching means comprises a forward biased PNP sixth amplifier transistor having a base, emitter and collector, said base of said sixth transistor being connected to said collector of said third transistor for switching said sixth transistor on when a trigger voltage is sensed.
Claim 22
Dependent Claim
79 words
A current sensing trigger and amplifier for sensing the dial pulses from a first subscriber in a step-by-step telephone system comprising: first and second semiconductor barrier means disposed in a series circuit relationship for receiving said dial pulses, said dial pulses establishing current therethrough; means for sensing a trigger voltage between said first and second semiconductor barrier means; and means for amplifying said trigger voltage and operating a stepping switch to connect said first subscriber to a second subscriber.
Claim 23
Dependent Claim
79 words
A current sensing trigger and amplifier for sensing the dial pulses from a first subscriber in a step-by-step telephone system comprising: first and second semiconductor barrier means disposed in a series circuit relationship for receiving said dial pulses, said dial pulses establishing current therethrough; means for sensing a trigger voltage between said first and second semiconductor barrier means; and means for amplifying said trigger voltage and operating a stepping switch to connect said first subscriber to a second subscriber.
Claim 24
Dependent Claim
50 words
The current sensing trigger and amplifier of claim 21 wherein said first and second semiconductor barrier means comprise a transistor trigger having a base, a collector and an emitter, said dial pulses being applied such that a current is established through said collector and said emitter of said transistor trigger.
Claim 25
Dependent Claim
25 words
The current sensing trigger and amplifier of claim 22 wherein said transistor trigger comprises an NPN transistor that is forward biased by said dial pulses.
Claim 26
Dependent Claim
24 words
The current sensing trigger and amplifier of claim 23 wherein said means for sensing a trigger voltage comprises said base of said transistor trigger.
Claim 27
Dependent Claim
23 words
The current sensing trigger and amplifier of claim 21 wherein said first and second semiconductor barrier means are first and second trigger diodes.
Claim 28
Dependent Claim
38 words
The current sensing trigger of claim 25 wherein said first and second trigger diodes and said means for generating dial pulses are connected such that said first and second trigger diodes are forward biased by said dial pulses.
Claim 29
Dependent Claim
55 words
The current sensing trigger and amplifier of claim 21 wherein said means for amplifying said trigger voltage and operating said stepping switch comprises: a normally closed first switching means for applying power to said stepping switch; and a normally open second switching means for isolating an enabling relay, for enabling operation of said stepping switch.
Claim 30
Dependent Claim
56 words
The current sensing trigger and amplifier of claim 27 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises means for opening said first switching means and closing said second switching means, when a trigger voltage is sensed, to isolate said stepping switch and apply power to said enabling relay, respectively.
Claim 31
Dependent Claim
52 words
The current sensing trigger and amplifier of claim 28 wherein said normally closed first switching means and said normally open second switching means are both connected to ground for alternately connecting ground to electrical circuits containing said stepping switch and said enabling relay, respectively, whereby a set of break/make contacts are simulated.
Claim 32
Dependent Claim
64 words
The current sensing trigger and amplifier of claim 27 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a normally open third switching means for isolating a second relay, said means for opening said first switching means and closing said second switching means further comprising means for closing said third switching means when a trigger voltage is sensed.
Claim 33
Dependent Claim
66 words
The current sensing trigger and amplifier of claim 21 wherein said means for amplifying said trigger voltage and operating said stepping switch comprises a forward biased PNP first amplifier transistor having a base, emitter and collector, said base of said first transistor being connected to said means for sensing a trigger voltage such that said first transistor is switched on when a trigger voltage is sensed.
Claim 34
Dependent Claim
70 words
The current sensing trigger and amplifier of claim 31 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a forward biased PNP second amplifier transistor having a base, emitter and collector, said base and said emitter of said second transistor being connected to said collector and said emitter of said first transistor for switching said second transistor off when a trigger voltage is sensed.
Claim 35
Dependent Claim
64 words
The current sensing trigger and amplifier of claim 32 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a forward biased PNP third amplifier transistor having a base, emitter and collector, said base of said third transistor being connected to said emitter of said second transistor for switching said third transistor off when a trigger voltage is sensed.
Claim 36
Dependent Claim
56 words
The current sensing trigger and amplifier of claim 33 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises: a normally closed first switching means for applying power to said stepping switch; and a normally open second switching means for isolating an enabling relay, for enabling operation of said stepping switch.
Claim 37
Dependent Claim
50 words
The current sensing trigger and amplifier of claim 34 wherein said first, second and third amplifier transistors comprise means for opening said first switching means and closing said second switching means, when a trigger voltage is sensed, to isolate said stepping switch and apply power to said enabling relay, respectively.
Claim 38
Dependent Claim
52 words
The current sensing trigger and amplifier of claim 35 wherein said normally closed first switching means and said normally open second switching means are both connected to ground for alternately connecting ground to electrical circuits containing said stepping switch and said enabling relay, respectively, whereby a set of break/make contacts are simulated.
Claim 39
Dependent Claim
57 words
The current sensing trigger and amplifier of claim 36 wherein said normally closed first switching means comprises a forward biased NPN fourth amplifier transistor having a base, emitter and collector, said base of said fourth transistor being connected to said collector of said third transistor for switching said fourth transistor off when a trigger voltage is sensed.
Claim 40
Dependent Claim
57 words
The current sensing trigger and amplifier of claim 37 wherein said normally open second switching means comprises a forward biased PNP fifth amplifier transistor having a base, emitter and collector, said base of said fifth transistor being connected to said collector of said second transistor for switching said fifth transistor on when a trigger voltage is sensed.
Claim 41
Dependent Claim
56 words
The current sensing trigger and amplifier of claim 38 wherein said means for amplifying said trigger voltage and operating said stepping switch further comprises a normally open third switching means for isolating a second relay, said first, second and third amplifier transistors comprising means for closing said third switching means when a trigger voltage is sensed.
Claim 42
Dependent Claim
57 words
The current sensing trigger and amplifier of claim 39 wherein said normally open third switching means comprises a forward biased PNP sixth amplifier transistor having a base, emitter and collector, said base of said sixth transistor being connected to said collector of said third transistor for switching said sixth transistor on when a trigger voltage is sensed.
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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) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |