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 = '423') AND (category.subclass = '422') ORDER BY date ASC, patent, type

Total of 1 patents found where: Class is '423'; Subclass is '422';

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
 1919
U 1,312,053 August 5, 1919 Process of Decomposing Potassium Silicates
Process of extracting potassium to be used in glass manufacture (see patent 1,327,781; 1,327,782)		 SCHOLES, Samuel R.
 Glass H. C. Fry Glass Co.

Total of 0.00 seconds