CH235154A
(en )
1944-11-15
Telecommunication system.
CH210435A
(en )
1940-07-15
Multiple telephone system.
CH232790A
(en )
1944-06-15
Electric telecommunication system.
GR6019B
(en )
1936-09-28
ELECTRIC CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET NUMBER RECEIVED BY TELEPHONE DISC.
GR6020B
(en )
1936-09-28
ELECTRICAL CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET NUMBER RECEIVED BY TELEPHONE DISC.
CH205038A
(en )
1939-05-31
Rotary selector for electrical telecommunications systems.
CH231614A
(en )
1944-03-31
Electric telecommunication system.
CH239303A
(en )
1945-09-30
Telecommunication system.
GR6021B
(en )
1936-09-28
ELECTRIC CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET NUMBER RECEIVED BY TEN ELECTRIC PUSHY BUTTONS.
CH194900A
(en )
1937-12-31
Telephone receiver.
CH240076A
(en )
1945-11-30
Telephone switchboard.
FR837587A
(en )
1939-02-14
Secret telecommunications system
GR7617B
(en )
1938-08-29
ELECTRIC CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET COMBINATION RECEIVED BY ELECTRIC BUTTONS.
CH234264A
(en )
1944-09-15
Telephone system.
GR8984B
(en )
1940-05-03
ELECTRIC CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET WORD.
GR7574B
(en )
1938-08-05
ELECTRICAL CIRCUIT RESTORATION SYSTEM FOR RECEIVING A SECRET NUMBER OR SECRET WORD RECEIVED BY PUSHING ELECTRIC KEYS.
CH202671A
(en )
1939-01-31
Telegraph system.
CH236317A
(en )
1945-01-31
Repeater circuit for telecommunications installations.
CH210928A
(en )
1940-08-15
Circuit device for carrier-frequency communication.
CH211385A
(en )
1940-09-15
Telecommunication system.
DK56913C
(en )
1939-11-13
Telephone system.
DK57614C
(en )
1940-05-20
Electrical Protection System.
ES146102A1
(en )
1940-12-01
Improvements in electrical communication systems.
GR7662B
(en )
1938-09-21
ELECTRIC CIRCUIT RESTORATION SYSTEM FOR COOLING SECRET COMBINATION RECEIVED BY ELECTRIC BUTTON.
CH217635A
(en )
1941-10-31
Telecommunications exchange system.