US4361731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coin telephone control circuit
Assignee: AT&T Inc
•
Filing: 1981-02-13
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Granted: 1982-11-30
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Expires: 2001-02-13
Abstract
Abstract Coins deposited in a coin telephone are collected or refunded by selectively discharging one of a plurality of capacitors (10,12) through a current limiter (46) for a period just long enough to operate the coin control relay (38) in the telephone. Use of this current limiter minimizes the drain of power from the remote terminal of a subscriber loop carrier system which derives all of its power from a telephone central office. A second current limiter (24) limits the rate at which the capacitors are charged.
Inventors
- 👤 Lanny S. Smoot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:10
CPC Classifications
H; H04; H04M; H04M17/00; H04M17/02; H04M17/023
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
41 words
A coin telephone control circuit CHARACTERIZED BY means for providing a constant current pulse to effect collection or refund of coins in said coin telephone (38), said means including a plurality of capacitors (10, 12) connected in parallel for storing energy.
Claim 2
Dependent Claim
41 words
A coin telephone control circuit CHARACTERIZED BY means for providing a constant current pulse to effect collection or refund of coins in said coin telephone (38), said means including a plurality of capacitors (10, 12) connected in parallel for storing energy.
Claim 3
Dependent Claim
23 words
The coin telephone control circuit according to claim 1 further CHARACTERIZED BY means (34,36,20,22) for selectively discharging said capacitors one at a time.
Claim 4
Dependent Claim
25 words
The coin telephone control circuit according to claim 2 further CHARACTERIZED BY means (30) for limiting the discharge of said capacitors for a selected period.
Claim 5
Dependent Claim
25 words
The coin telephone control circuit according to claim 2 further CHARACTERIZED BY means (16,18) for limiting the discharge of said capacitors below a threshold voltage.
Claim 6
Dependent Claim
24 words
The coin telephone control circuit according to claim 1 further CHARACTERIZED BY means (24) for limiting the rate at which said capacitors are charged.
Claim 7
Dependent Claim
29 words
The coin telephone control circuit according to claim 1 further CHARACTERIZED BY means (46) for limiting the rate at which said capacitors are discharged to produce said current pulse.
Claim 8
Dependent Claim
26 words
The coin telephone control circuit according to claim 1 further CHARACTERIZED BY means for detecting whether said coins were collected in response to said current pulse.
Claim 9
Dependent Claim
25 words
The coin telephone control circuit according to claim 7 further CHARACTERIZED BY means (32) for providing said current pulse repeatedly until said coins are collected.
Claim 10
Dependent Claim
70 words
A coin telephone control circuit for collecting or refunding coins, said circuit comprising a plurality of capacitors (10,12), means (30,32,34,36,20,22) for selectively discharging said capacitors one at a time through said coin telephone, means (46) for limiting the flow of discharge current through said coin telephone, means (24) for limiting the current for charging said capacitors, and means (16,18) for preventing the discharge of said capacitors below a threshold value.
Claim 11
Dependent Claim
70 words
A coin telephone control circuit for collecting or refunding coins, said circuit comprising a plurality of capacitors (10,12), means (30,32,34,36,20,22) for selectively discharging said capacitors one at a time through said coin telephone, means (46) for limiting the flow of discharge current through said coin telephone, means (24) for limiting the current for charging said capacitors, and means (16,18) for preventing the discharge of said capacitors below a threshold value.
References Cited (Backward Citations)
US4010328A
Cited
US4197433A
Cited
US4152546A
Cited
US4174468A
Cited
US4197432A
Cited
US4243841A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-29 | 1986-05-31 | 1986-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-29 | 1990-05-31 | 1990-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-29 | 1994-05-31 | 1994-11-30 | $7700.00 | Window Closed / Lapsed |