3372551

Information

• Patent Grant
• 3372551

• References
• Source

• Patent Number

  3,372,551

• Date Filed

  Not available

• Date Issued

  Tuesday, March 12, 1968
  56 years ago

• CPC

  • E21D23/081 - forming parts of the roof supports
  • E21D15/55 - of prop heads or feet
  • E21D23/0069 - without essential advancing shifting devices
  • E21D23/06 - Special mine caps or special tops of pit-props for permitting step-by-step movement

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 091 - Motors: expansible chamber type
  • 248 - Supports
  • 254 - Implements or apparatus for applying pushing or pulling force