BE440889A - - Google Patents
Info
- Publication number
- BE440889A BE440889A BE440889DA BE440889A BE 440889 A BE440889 A BE 440889A BE 440889D A BE440889D A BE 440889DA BE 440889 A BE440889 A BE 440889A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/02—Constructional features of telephone sets
- H04M1/03—Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/12—Sanitary or hygienic devices for mouthpieces or earpieces, e.g. for protecting against infection
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Public Health (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Telephone Set Structure (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL220359X | 1939-11-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE440889A true BE440889A (en:Method) |
Family
ID=19779319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE440889D BE440889A (en:Method) | 1939-11-22 |
Country Status (4)
| Country | Link |
|---|---|
| BE (1) | BE440889A (en:Method) |
| CH (1) | CH220359A (en:Method) |
| DE (1) | DE737071C (en:Method) |
| FR (1) | FR871481A (en:Method) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1078179B (de) * | 1957-02-01 | 1960-03-24 | Draegerwerk Ag | Mikrophon fuer Gasmasken |
-
0
- BE BE440889D patent/BE440889A/xx unknown
-
1940
- 1940-11-16 DE DEP81547D patent/DE737071C/de not_active Expired
-
1941
- 1941-02-07 CH CH220359D patent/CH220359A/de unknown
- 1941-04-10 FR FR871481D patent/FR871481A/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CH220359A (de) | 1942-03-31 |
| DE737071C (de) | 1943-07-05 |
| FR871481A (fr) | 1942-04-27 |