← Back to Companies

Electrical Research Products Inc

Electrical

Active Patents

0

Total Holdings

4

Patent Holdings

Filter in Explorer →

Patent No.	Title	Status	Filing Date	Grant Date	Claims	Actions
US2249606A	Stereophonic sound recording system	Expired / Lapsed	1938-03-22	1941-07-15	0	Details
US2008881A	Motion picture projecting and sound reproducing apparatus	Expired / Lapsed	1931-06-01	1935-07-23	0	Details
US1939074A	Sound picture recording system	Expired / Lapsed	1931-02-27	1933-12-12	0	Details
US1814263A	Electrical control system	Expired / Lapsed	1927-04-01	1931-07-14	0	Details