Jeffrey Mine Insulator ( CD 185 ) French Drain Slit & Duct Hole Apparatus (6 of 6)

By Michael Gibbons; posted March 30, 2024

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CD# 185

Special Mine Insulator

Jeffrey MFG Co., Columbus, Ohio

Magazine Reference: Malleable Iron Pins for Mine Feeder System, from Electrical Review, June 8, 1904, page 206.

Dates:

Patent applied for November 29, 1993

Government Patented September 25, 1894

Insulators say Patent Sep. 25, 1894

Advertisement from 1904 says Pat. Sept. 25, 1898.

Mounting pin says Patented "Dec. 7-15"… IE Dec. 7, 1915 ?

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