2420755

Information

• Patent Grant
• 2420755

• References
• Source

• Patent Number

  2,420,755

• Date Filed

  Not available

• Date Issued

  Tuesday, May 20, 1947
  77 years ago

• CPC

  • E21C27/14 - breaking-down effected by force or pressure applied to side of slit
  • E21D23/0073 - with advancing shifting devices connected therewith

• US Classifications

  • 299 - Mining or in situ disintegration of hard material
  • 180 - Motor vehicles