US3858008A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line busying circuit
Assignee: PHONE AID CO Inc
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Filing: 1973-05-21
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Granted: 1974-12-31
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Expires: 1993-05-21
Abstract
Abstract A line busying circuit for busying sequentially subsequent subscriber lines of a telephone system in response to use of a first line in order to prevent completion of a call by line hunt equipment to a nonbusy and unattended telephone set. The circuit includes a ringing signal recognition arrangement operable in response to a ringing signal of predetermined duration on the first line but not in response to transients or other spurious signals. When a ringing signal is detected, a control circuit places subsequent sequential subscriber lines in a false busy condition for a limited period of time.
Inventors
- 👤 M Remec
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:03
CPC Classifications
H; H04; H04Q; H04Q3/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
A line busying circuit for use with a plurality of sequential telephone lines associated with a telephone system having line hunt equipment, said circuit comprising: sensing means coupled to a sequentially first line for sensing use of said first line; a false busy circuit connected to at least one line subsequent to said first line; means for normally maintaining said subsequent line in an undisturbed condition; and control means coupled between said sensing means and said false busy circuit and operable in response to the sensing of use of said first line for operating said false busy circuit to place said subsequent line in a busy condition; said sensing means including first detecting means for detecting the inception of a signal on the first line, second detecting means for detecting the persistance of the signal after a predetermined time delay, and means for providing an output signal only when inception and persistance of a signal are detected.
Claim 2
Dependent Claim
157 words
A line busying circuit for use with a plurality of sequential telephone lines associated with a telephone system having line hunt equipment, said circuit comprising: sensing means coupled to a sequentially first line for sensing use of said first line; a false busy circuit connected to at least one line subsequent to said first line; means for normally maintaining said subsequent line in an undisturbed condition; and control means coupled between said sensing means and said false busy circuit and operable in response to the sensing of use of said first line for operating said false busy circuit to place said subsequent line in a busy condition; said sensing means including first detecting means for detecting the inception of a signal on the first line, second detecting means for detecting the persistance of the signal after a predetermined time delay, and means for providing an output signal only when inception and persistance of a signal are detected.
Claim 3
Dependent Claim
27 words
The line busying circuit of claim 1, said first and second detecting means comprising means for detecting the presence of a ringing signal on said first line.
Claim 4
Dependent Claim
33 words
The line busying circuit of claim 1, said control means including timer means for returning said subsequent lines to the undisturbed condition a predetermined time after sensing of use of said first line.
Claim 5
Dependent Claim
22 words
The line busying circuit of claim 1, said false busy circuit including resistance means and switching means coupled to said subsequent line.
Claim 6
Dependent Claim
118 words
A line busying circuit for use with a plurality of sequential telephone lines associated with line hunt equipment, said line busying circuit comprising: an amplifier coupled to the sequentially first line; a gate having two inputs and an output; one gate input being coupled to said amplifier for operation in response to presence of a signal on the first line; a time coupled between said amplifier and the second gate input for operating the second gate input a predetermined time after presence of a signal on the first line; and means connected between the gate output and at least one sequentially subsequent line for busying said subsequent line in response to simultaneous operation of both said gate inputs.
Claim 7
Dependent Claim
118 words
A line busying circuit for use with a plurality of sequential telephone lines associated with line hunt equipment, said line busying circuit comprising: an amplifier coupled to the sequentially first line; a gate having two inputs and an output; one gate input being coupled to said amplifier for operation in response to presence of a signal on the first line; a time coupled between said amplifier and the second gate input for operating the second gate input a predetermined time after presence of a signal on the first line; and means connected between the gate output and at least one sequentially subsequent line for busying said subsequent line in response to simultaneous operation of both said gate inputs.
Claim 8
Dependent Claim
60 words
The line busying cirCuit of claim 5, said last mentioned means including a second timer coupled to said gate output, a relay winding energized for a predetermined interval upon operation of said second timer, at least one set of normally open relay contacts controlled by said winding, and resistive means in circuit with said contacts and with said subsequent line.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |