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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 = '324') AND (category.subclass = '552') ORDER BY assigned_to ASC, date, patent, type

Total of 4 patents found where: Class is '324'; Subclass is '552';

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T / S Patent Date Description Patentee Category Assigned To
U 1,515,864 November 18, 1924 Method of Testing Insulators
Testing method by extending the flashover distance
LAPP, Grover W.
Testing  
 The Ohio Brass Co.
U 1,750,699 March 18, 1930 Process and Apparatus for Testing Insulators
Apparatus to run a high voltage test on insulators (see 1,796,427)
AUSTIN, Arthur O.
Manufacturing The Ohio Brass Co.
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.
U 1,796,429 March 17, 1931 Apparatus for Testing Insulators
Apparatus to run a high voltage test on insulators (see 1,796,427)
AUSTIN, Arthur O.
Manufacturing The Ohio Brass Co.

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