[Trade Journal]
Publication: Western Electrician
Chicago, IL, United States
vol. 41, no. 20, p. 403, col. 3
ILLUSTRATED ELECTRICAL PATENT RECORD.
Issued (United States Patent Office) November 5, 1907.
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| No. 870,187. — Wall Insulator |
870,187. Wall Insulator. Fred M. Locke, Victor, N. Y. Application filed July 18, 1907.
A wall insulator comprises an entrance tube and a pair of concavo-convex disks surrounding the tube and each provided with a series of concentric annular flanges projecting from their concave faces. (See cut.)
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