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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 = '191') AND (category.subclass = '23R') ORDER BY date ASC, patent, type

Total of 2 patents found where: Class is '191'; Subclass is '23R';

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T / S Patent Date Description Patentee Category Assigned To
 1889
U 402,836 May 7, 1889 Insulator and Holder for Electric Railways
Third rail insulator clamps the rail upsidedown.
JENNINGS, Byron
Third Rail  
 1893
U 503,039 August 8, 1893 Conductor Support and Insulator
miscellaneous wire support for underground trolley wire & insulator with hole in crown
ESSICK, William B.
Miscellaneous  

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