2913236

Information

• Patent Grant
• 2913236

• References
• Source

• Patent Number

  2,913,236

• Date Filed

  Not available

• Date Issued

  Tuesday, November 17, 1959
  66 years ago

• CPC

  • E21D9/1053 - for making a slit along the perimeter of the tunnel profile, the remaining core being removed subsequently

• US Classifications

  • 175 - Boring or penetrating the earth
  • 238 - Railways: surface track
  • 299 - Mining or in situ disintegration of hard material