Classifications

• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D3/00—Hot-water central heating systems
  • F24D3/02—Hot-water central heating systems with forced circulation, e.g. by pumps

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9003155

Family Applications (1)

Country Status (2)

• 0
  • BE BE362471D patent/BE362471A/xx unknown
• 1927
  • 1927-07-09 FR FR649156D patent/FR649156A/fr not_active Expired

Also Published As

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