3717844

Information

• Patent Grant
• 3717844

• References
• Source

• Patent Number

  3,717,844

• Date Filed

  Not available

• Date Issued

  Tuesday, February 20, 1973
  51 years ago

• CPC

  • E21B33/0355 - Control systems
  • C09B67/0025 - Crystal modifications; Special X-ray patterns
  • E21B47/14 - using acoustic waves
  • G08C23/02 - using infrasonic, sonic or ultrasonic waves
  • H04B11/00 - Transmission systems employing sonic, ultrasonic or infrasonic waves
  • H04Q9/12 - using combinations of frequencies
  • Y10S367/901 - Noise or unwanted signal reduction in nonseismic receiving system

• US Classifications

  • 367 - Communications, electrical: acoustic wave systems and devices
  • 128 - Surgery
  • 375 - Pulse or digital communications
  • 455 - Telecommunications