[Trade Journal] Publication: Electrical World New York, NY, United States |
OUR ILLUSTRATED RECORD OF ELECTRICAL PATENTS.
U. S. Patents Issued August 19, 1890. · · 434,879. Electric Insulator; Samuel Oakman, of Melrose, Mass. Application filed Sept. 13, 1889. In an insulator, the combination of the petticoat and a series of internal annular projections having inclined tops and flat bases adopted to act as waterstops. · · |
Keywords: | Samuel Oakman |
Researcher notes: | |
Supplemental information: | Patent: 434,879 |
Researcher: | Glenn Drummond |
Date completed: | November 23, 2010 by: Glenn Drummond; |