3392532

Information

• Patent Grant
• 3392532

• References
• Source

• Patent Number

  3,392,532

• Date Filed

  Not available

• Date Issued

  Tuesday, July 16, 1968
  56 years ago

• CPC

  • E21D23/12 - Control
  • E21D17/0206 - Hydraulically operated extension devices
  • E21D23/06 - Special mine caps or special tops of pit-props for permitting step-by-step movement
  • E21D23/14 - Effecting automatic sequential movement of supports
  • E21D23/142 - Measuring the advance of support units with respect to external points of reference

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 091 - Motors: expansible chamber type