| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 15 |
| # | Industry | |
|---|---|---|
| #1 | Telecommunications | |
| #2 | Audio-visual technology | |
| #3 | Electrical machinery and energy | |
| #4 | Control |
| # | Technology | |
|---|---|---|
| #1 | Telephonic communication | |
| #2 | Loudspeakers and microphones | |
| #3 | Installation of electric cables | |
| #4 | Alarm systems |
| # | Name | Total Patents |
|---|---|---|
| #1 | Teichmann Wilfried | 6 |
| #2 | Lenk Friedrich | 2 |
| #3 | Heider F W | 2 |
| #4 | Hermann Lenk Friedrich | 1 |
| #5 | Wilhelm Heider Friedrich | 1 |
| #6 | Teichmann Wilfreid | 1 |
| Publication | Filing date | Title |
|---|---|---|
| DE2141126A1 | COMBINED BELLING, DOOR INTERCOM AND OPENING SYSTEM | |
| DE1926073A1 | Circuit arrangement for combined door intercom and opener systems in single-family houses | |
| DE1923219A1 | Circuit arrangement for connecting one of two door stations to a combined bell, opener and intercom | |
| DE1911540A1 | Circuit arrangement for combined door intercom and door opener systems in apartment buildings |