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 = '252') AND (category.subclass = '514') ORDER BY date ASC, patent, type

Total of 1 patents found where: Class is '252'; Subclass is '514';

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
 1934
U 1,973,076 September 11, 1934 Insulator
RFI: coat crown with gold, platinum, bismuth & semi-conductive area
HUNT, Marsden H.
RFI Westinghouse Electric & Mfg. Co.

Total of 0.00 seconds