3771978

Information

• Patent Grant
• 3771978

• References
• Source

• Patent Number

  3,771,978

• Date Filed

  Not available

• Date Issued

  Tuesday, November 13, 1973
  51 years ago

• CPC

  • B21C37/185 - starting from sheet material
  • B21C37/124 - the tubes having a special shape
  • Y10S29/041 - Taper tube making
  • Y10T428/12201 - Width or thickness variation or marginal cuts repeating longitudinally
  • Y10T428/12236 - Panel having nonrectangular perimeter
  • Y10T428/12285 - Single taper [e.g., ingot, etc.]
  • Y10T428/12333 - Helical or with helical component

• US Classifications

  • 428 - Stock material or miscellaneous articles
  • 029 - Metal working
  • 219 - Electric heating