| Patents for H04M 17 - Prepayment telephone systems (5,258) |
|---|
| 05/25/1982 | CA1124418A1 Digital coin circuit |
| 05/18/1982 | CA1123979A1 Vandal resistant public telephone |
| 04/20/1982 | US4326123 Telephone credit card system |
| 04/20/1982 | US4326103 Coin telephone monitor circuit |
| 04/06/1982 | US4323733 Range extender with variable gain for coin telephone loops |
| 03/17/1982 | EP0047524A1 Communications system, particularly telephone system, for the connection of mobile subscriber terminal equipments |
| 01/06/1982 | EP0043190A1 Cash-box security arrangements |
| 12/09/1981 | EP0041261A1 Electronic-card prepayment telephone |
| 11/17/1981 | CA1112777A1 Coin box removal information processing arrangement |
| 07/21/1981 | CA1105627A1 Telephone station coin memory and control system |
| 07/07/1981 | US4277647 Coin signaling system |
| 05/12/1981 | US4267411 Public telephone security bracket |
| 03/24/1981 | CA1098227A1 Method and apparatus for receiving disparate sequences of spaced tone bursts |
| 03/03/1981 | US4254308 Vandal resistant public telephone |
| 01/06/1981 | US4243841 Digitally activated coin control circuit |
| 10/28/1980 | CA1088688A1 Control circuit for pay telephones and the like |
| 07/29/1980 | CA1082826A1 Called party fraud detection in an automated coin system |
| 07/01/1980 | CA1080865A2 Out-of band signaling method and apparatus to adapt payphones to telephone systems |
| 06/17/1980 | US4208549 Coin surveillance apparatus |
| 06/11/1980 | EP0012102A1 Public telephone sets |
| 06/03/1980 | US4206321 Pay telephone alarm system with audit means |
| 05/29/1980 | WO1980001126A1 Coin-operated telephone apparatus |
| 04/22/1980 | US4199659 Electronic prepay adapter circuit for central office telephone equipment |
| 04/16/1980 | EP0009684A1 A telephone-switching system |
| 04/15/1980 | US4198545 Automatic call timing telephone apparatus |
| 04/02/1980 | EP0009106A1 Circuit arrangement for energizing an electromagnet in a coin-freed telephone station |
| 03/11/1980 | US4192972 Pay-telephone station with deferred collection |
| 01/29/1980 | US4186275 Initial rate override circuit |
| 12/11/1979 | CA1068022A1 Automated coin arrangement providing interference free coin deposit detection during announcements |
| 11/13/1979 | US4174468 Digital coin circuit |
| 10/23/1979 | CA1065074A1 Coin box signaling arrangement |
| 06/19/1979 | CA1056971A2 Telephone pay station with fraudulent chain-dialing prevention circuit |
| 06/12/1979 | CA1056525A1 Pay telephone applique for subscriber carrier telephone system |
| 04/24/1979 | US4151380 Post mounted public telephone |
| 04/17/1979 | CA1052922A1 Telephone pay station providing limited coin-free calls |
| 02/13/1979 | US4139736 Central office coin repeater modification circuit |
| 01/23/1979 | US4136262 Telephone paystation |
| 11/07/1978 | US4124775 Coin box removal information processing arrangement |
| 11/07/1978 | US4124774 Telephone station coin memory and control system |
| 10/31/1978 | US4123623 Pay telephone alarm and audit system |
| 10/24/1978 | US4122308 Telephone call metering device |
| 08/08/1978 | US4105867 Control circuit for pay telephones and the like |
| 02/28/1978 | US4076962 Method and apparatus for receiving disparate sequences of spaced tone bursts |
| 02/14/1978 | US4074079 Coin telephone antifraud system |
| 12/13/1977 | US4063036 Coin telephone system having restricted coin-free dialing capability |
| 09/06/1977 | US4046962 Called party fraud detection in an automated coin system |
| 08/09/1977 | US4041243 Coin box signaling arrangement |
| 08/02/1977 | US4039768 Pay telephone station monitor system |
| 07/19/1977 | US4037067 Anti-vandalism protective attachment device for a pay telephone |
| 06/21/1977 | US4031325 Called party fraud prevention in an automated coin system |
| 06/21/1977 | US4031324 Automated coin arrangement providing interference free coin deposit detection during announcements |
| 06/07/1977 | US4028494 Escrow telephone coin collection circuit and method |
| 03/01/1977 | US4010328 Out-of-band signaling method and apparatus to adapt payphones to telephone systems |
| 12/14/1976 | US3997726 Coin telephone set |
| 11/16/1976 | US3992588 Multiple digit dialing module |
| 05/25/1976 | US3959607 Communications booth with automatic accounting for telephone and booth usage |
| 04/20/1976 | US3952160 Coin telephone arrangement to obviate acoustically coupled fraud |
| 02/10/1976 | US3938093 Coin operated terminal |