2903252

Information

• Patent Grant
• 2903252

• References
• Source

• Patent Number

  2,903,252

• Date Filed

  Not available

• Date Issued

  Tuesday, September 8, 1959
  65 years ago

• CPC

  • E21D1/06 - with shaft-boring cutters
  • E21B4/18 - Anchoring or feeding in the borehole
  • E21B7/28 - Enlarging drilled holes
  • E21D3/00 - Raising shafts
  • E21D9/10 - Making by using boring or cutting machines

• US Classifications

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