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)

Publications (1)

Family

ID=19779319

Family Applications (1)

Country Status (4)

Families Citing this family (1)

• 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

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