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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 = '425') AND (category.subclass = '423') ORDER BY date ASC, patent, type

Total of 3 patents found where: Class is '425'; Subclass is '423';

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T / S Patent Date Description Patentee Category Assigned To
U 1,556,440 October 6, 1925 Press for Making Insulators and the Like
Press for forming threads in porcelain insulators and to prevent damaging the threaded pinhole once formed
HIBBARD, Robert L.
U 1,625,514 April 19, 1927 Apparatus for Forming Plastic Materials
Improved press to form insulator shape from wet process clay and cut in threaded pinhole
AUSTIN, Arthur O.
MACLEOD, Donald Keith
Press The Ohio Brass co.
U 1,663,329 March 20, 1928 Forming and Tapping Machine
Machine to form threads in plastic clay bodies
AUSTIN, Arthur O.
Manufacturing The Ohio Brass Co.

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