3821609

Information

• Patent Grant
• 3821609

• References
• Source

• Patent Number

  3,821,609

• Date Filed

  Not available

• Date Issued

  Friday, June 28, 1974
  50 years ago

• CPC

  • E21F9/00 - Devices preventing sparking of machines or apparatus
  • E21C35/04 - Safety devices

• US Classifications

  • 361 - Electricity: electrical systems and devices