|
GB362444A
|
|
Improvements in electrical signalling apparatus
|
|
GB339308A
|
|
Improvements in electrical signalling apparatus
|
|
DE512039C
|
|
Electric display device
|
|
GB325614A
|
|
Improvements in electrical selectors
|
|
GB324430A
|
|
Improvements in automatic telephone systems
|
|
GB321303A
|
|
Improvements in fire alarm systems in conjunction with telephone exchange systems
|
|
GB320706A
|
|
Improvements in telephone exchange systems
|
|
GB321426A
|
|
Improvements in electric signalling or indicating apparatus
|
|
GB321415A
|
|
Improvements in electric signalling or indicating apparatus
|
|
GB313682A
|
|
Telegraph concentrator
|
|
GB303267A
|
|
Improvements in junction working between exchanges in telephone systems comprising automatic exchanges
|
|
GB303465A
|
|
Improvements in electric signalling devices
|
|
GB302422A
|
|
Improvements in electric relay arrangements
|
|
GB287276A
|
|
Improvements in telephone systems
|
|
GB268150A
|
|
Improvements in private automatic branch telephone exchanges
|
|
GB252226A
|
|
Improvements in railway-platform and other like indicators
|
|
GB243140A
|
|
Improvements in automatic telephone systems
|
|
US1645972A
|
|
Telephone trunking scheme
|
|
GB240217A
|
|
Improvements in and connected with selecting mechanism for electrical signalling apparatus
|
|
US1607387A
|
|
Party-line telephone
|
