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SELECT DISTINCT patent.*, YEAR(date) as year FROM patent LEFT JOIN category ON category.patent = patent.patent AND category.type = patent.type WHERE (category.class = '310') AND (category.subclass = '75B') ORDER BY date ASC, patent, type

Total of 1 patents found where: Class is '310'; Subclass is '75B';

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T / S Patent Date Description Patentee Category Assigned To
 1931
U 1,796,427 March 17, 1931 Process and Apparatus for Testing Insulators
Apparatus to run a high voltage test on insulators (see 1,750,699 and 1,796,427)		 AUSTIN, Arthur O.
 Manufacturing The Ohio Brass Co.

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