| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Canada | 4 | |
| #2 | United States | 4 | |
| #3 | Germany | 3 | |
| #4 | France | 3 | |
| #5 | United Kingdom | 3 |
| # | Industry | |
|---|---|---|
| #1 | Control | |
| #2 | Digital networks | |
| #3 | Audio-visual technology | |
| #4 | Telecommunications |
| # | Technology | |
|---|---|---|
| #1 | Alarm systems | |
| #2 | Registering devices | |
| #3 | Digital information transmission | |
| #4 | Telephonic communication | |
| #5 | Advertising |
| # | Name | Total Patents |
|---|---|---|
| #1 | Rollins Arch D | 4 |
| #2 | Ederer Lothar A | 2 |
| #3 | Calkins Chauncey L | 2 |
| Publication | Filing date | Title |
|---|---|---|
| US2136711A | Dispatcher | |
| US2139466A | Annunciator | |
| GB394371A | Improvements in apparatus for transmitting and recording signals | |
| GB397859A | Improvements in or relating to electrically operated indicator systems | |
| GB397858A | Improvements in electric signalling systems | |
| US1795930A | Switchboard | |
| US1910887A | Transmitting and recording apparatus and process | |
| CA317708A | Dispatcher | |
| CA312651A | Signal transmitting and recording apparatus | |
| CA318120A | Switch board | |
| CA307493A | Annunciator |