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 WHERE (category = 'Spark Gap') ORDER BY date ASC, patent, type

Total of 1 patents found where: Category is 'Spark Gap';

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
 1946
U 2,392,342 January 8, 1946 Combined Spark Gap and Insulator
CD 186, CD 186.1, CD 186.2; Transparent glass insulator with spark gap within the insulator for signal circuits		 STEINMAYER, Alwin G.
 Spark Gap Line Material Co.

Total of 0.01 seconds