|
US2735083A
(en)
*
|
|
1956-02-14 |
|
Finlay |
|
US2733433A
(en)
*
|
|
1956-01-31 |
|
morrison |
|
US2674734A
(en)
*
|
1950-07-20 |
1954-04-06 |
Automatic Elect Lab |
Electronic ringing frequency generator
|
|
NL82729C
(en:Method)
*
|
1951-07-14 |
|
|
|
|
NL88838C
(en:Method)
*
|
1951-12-01 |
|
|
|
|
US2717279A
(en)
*
|
1951-12-28 |
1955-09-06 |
Bell Telephone Labor Inc |
Multiparty selective signaling and identification system
|
|
BE520260A
(en:Method)
*
|
1952-06-13 |
|
|
|
|
US2746028A
(en)
*
|
1952-08-05 |
1956-05-15 |
Bell Telephone Labor Inc |
Air raid warning system
|
|
DE1039595B
(de)
*
|
1952-08-30 |
1958-09-25 |
Siemens Ag |
Verfahren zur Ortsbestimmung undichter Stellen in mit einem gasfoermigen oder fluessigen Druckmedium gefuellten Rohren, insbesondere Kabelmaenteln
|
|
US2751578A
(en)
*
|
1953-02-04 |
1956-06-19 |
Ericsson Telefon Ab L M |
Fault indicator for plural connected devices
|
|
US2790965A
(en)
*
|
1953-12-17 |
1957-04-30 |
Bell Telephone Labor Inc |
Voice frequency alarm and remote control system
|
|
US2842753A
(en)
*
|
1954-06-08 |
1958-07-08 |
Harold I Ewen |
Monitoring systems
|
|
US2890281A
(en)
*
|
1954-09-27 |
1959-06-09 |
Friedmann Louis Martin |
Telephone alarm system
|
|
DE1067708B
(de)
*
|
1956-05-09 |
1959-10-22 |
Siemens Ag |
Anordnung zur Kennzeichnung des Herkunftsortes von Signalen in wechselstromgespeisten Meldeleitungen
|
|
US3029310A
(en)
*
|
1956-08-03 |
1962-04-10 |
Itt |
Frequency-controlled switch
|
|
US3058065A
(en)
*
|
1956-11-07 |
1962-10-09 |
Nielsen A C Co |
System for determining listening habits of wave signal receiver users
|
|
US2981940A
(en)
*
|
1957-03-11 |
1961-04-25 |
Ibm |
Communication systems
|
|
US3034099A
(en)
*
|
1958-12-15 |
1962-05-08 |
Gen Railway Signal Co |
Code communication system
|
|
US3122723A
(en)
*
|
1959-05-25 |
1964-02-25 |
Westinghouse Brake & Signal |
Remote control systems
|
|
US3137847A
(en)
*
|
1959-11-04 |
1964-06-16 |
Link Aviation Inc |
Signalling system
|
|
US3109068A
(en)
*
|
1960-01-25 |
1963-10-29 |
Gen Dynamics Corp |
Data handling system
|
|
US3263217A
(en)
*
|
1960-04-05 |
1966-07-26 |
Philips Corp |
Remote control system
|
|
US3099816A
(en)
*
|
1960-05-18 |
1963-07-30 |
Westinghouse Air Brake Co |
Remote indication systems
|
|
US3179931A
(en)
*
|
1960-11-18 |
1965-04-20 |
American Telephone & Telegraph |
Alarm transfer system
|
|
US3130277A
(en)
*
|
1960-12-29 |
1964-04-21 |
Bell Telephone Labor Inc |
Order wire and alarm circuits
|
|
CH404774A
(de)
*
|
1963-03-25 |
1965-12-31 |
Electrometre |
Einrichtung zur Fernübertragung von Signalen über ein Versorgungsnetz für elektrische Energie
|
|
US3678512A
(en)
*
|
1970-10-21 |
1972-07-18 |
Atomic Energy Commission |
Telemonitoring system
|
|
US4268822A
(en)
*
|
1978-10-18 |
1981-05-19 |
The Foxboro Company |
Apparatus for determining the state of each of a plurality of bi-state devices
|