Search the Insulator Patent Reference Library:

Build your search criteria. The patent must match all the values specified.
Select patent types: Utility   Design   Reissue
Patent number:
Date:
Year between: and
Patentee starting with:
City:
State:
Assigned To starting with:
Description containing:
Category:
Class:    Subclass:
Click Search when complete:
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 = '236') ORDER BY date ASC, patent, type

Total of 2 patents found where: Class is '425'; Subclass is '236';

View a patent by clicking on the patent number. You can sort by any of the columns by clicking on the column name.

T / S Patent Date Description Patentee Category Assigned To
 1920
U 1,342,053 June 1, 1920 Bushing Forming Machine
Machine to manufacture wall tubes and bushings		 MCKNIGHT, Oscar W.
 Wall Tube Brunt Tile & Porcelain Co.
 1923
U 1,471,907 October 23, 1923 Machine for Heading Porcelain Tubes and the Like
Machine to make porcelain wall tubes		 MASON, Albert G.
BUCKLEY, Lorenzo C.
 Wall Tube The R. Thomas & Sons Co.

Total of 0.00 seconds