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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 = '263') ORDER BY date ASC, patent, type

Total of 2 patents found where: Class is '425'; Subclass is '263';

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T / S Patent Date Description Patentee Category Assigned To
 1928
U 1,677,498 July 17, 1928 Apparatus for Undercutting Pinholes in the Center Shells of Insulators
Machine to undercut the pinhole for the suspension pin to prevent the pin from pulling out of the insulator.
SMITH, William Henry
Suspension Electric Service Supplies Co.
 1929
U 1,732,339 October 22, 1929 Apparatus for Finishing Insulator Shells
Machine to form the opening in the bottom of a top shell and form grooves in the sides of the opening to aid in cement adhesion between the top shell and the second shell.
OSBORNE, David H.
Manufacturing Electric Service Supplies Co.

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