3439954

Information

• Patent Grant
• 3439954

• References
• Source

• Patent Number

  3,439,954

• Date Filed

  Not available

• Date Issued

  Tuesday, April 22, 1969
  55 years ago

• CPC

  • E21C37/04 - by devices with parts pressed mechanically against the wall of a borehole or a slit
  • E21C37/02 - by wedges

• US Classifications

  • 299 - Mining or in situ disintegration of hard material