Electronic stethoscope

• US 3,160,708 A
• Filed: 07/13/1961
• Issued: 12/08/1964
• Est. Priority Date: 07/13/1961
• Status: Expired due to Term

• Current Assignee: Center John L, Francis M. Andries, Gordon J. Rabalais
• Original Assignee: Center John L, Francis M. Andries, Gordon J. Rabalais
• Inventors: Andries, Francis M., Center, John L., Rabalais, Gordon J.
• Application Number:
  US04/123,848
• Time in Patent Office: 1,244 Days
• US Class Current: 381/67
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Claims

1. SOUND-DETECTING APPARATUS COMPRISING A CONE-SHAPED BELL BEING OPEN AT THE WIDE END, A HOLLOW CHAMBER POSITIONED ADJACENT TO AND AXIALLY ALIGNED WITH SAID BELL, SAID CHAMBER HAVING AN OPENING COMMUNICATING WITH THE SMALL END OF SAID BELL, A THIN FLEXIBLE DIAPHRAGM HAVING A DIAMETER APPROXIMATING THAT OF SAID WIDE END OF SAID BELL AND POSITIONED WITHIN SAID CHAMBER CLOSELY ADJACENT SAID OPENING, SAID DIAPHRAGM SEPARATING A SMALL PORTION OF SAID CHAMBER FROM THE REMAINDER THEREOF, A FIRST NARROW AIR PASSAGE CONNECTING SAID SMALL PORTION TO ATMOSPHERE, A SECOND NARROW AIR PASSAGE CONNECTING SAID REMAINING PORTION OF SAID CHAMBER TO ATMOSPHERE, A COIL SECURED TO SAID FLEXIBLE DIAPHRAGM AND POSITIONED IN A MAGNETIC FIELD, AND AMPLIFYING MEANS HAVING AN INPUT CONNECTED TO SAID COIL.