2720390

Information

• Patent Grant
• 2720390

• References
• Source

• Patent Number

  2,720,390

• Date Filed

  Not available

• Date Issued

  Tuesday, October 11, 1955
  69 years ago

• CPC

  • E21B43/292 - using steerable or laterally extendable nozzles

• US Classifications

  • 175 - Boring or penetrating the earth
  • 299 - Mining or in situ disintegration of hard material
  • 405 - Hydraulic and earth engineering