3887236

Information

• Patent Grant
• 3887236

• References
• Source

• Patent Number

  3,887,236

• Date Filed

  Not available

• Date Issued

  Tuesday, June 3, 1975
  49 years ago

• CPC

  • E21B10/04 - with core destroying means
  • E21B10/06 - Roller core bits
  • E21B25/10 - Formed core retaining or severing means
  • E21D9/11 - with a rotary drilling-head cutting simultaneously the whole cross-section

• US Classifications

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