3927731

Information

• Patent Grant
• 3927731

• References
• Source

• Patent Number

  3,927,731

• Date Filed

  Not available

• Date Issued

  Tuesday, December 23, 1975
  49 years ago

• CPC

  • F01N1/125 - in combination with sound-absorbing materials

• US Classifications

  • 181 - Acoustics