3903988

Information

• Patent Grant
• 3903988

• References
• Source

• Patent Number

  3,903,988

• Date Filed

  Not available

• Date Issued

  Tuesday, September 9, 1975
  49 years ago

• CPC

  • G10K5/02 - Ultrasonic whistles
  • B63H11/12 - the propulsive medium being steam or other gas

• US Classifications

  • 181 - Acoustics
  • 116 - Signals and indicators