Portfolio comparison
ELECTRO STRING INSTR CORP vs Central Investment Corp
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Company A
ELECTRO STRING INSTR CORP
Patents indexed
1
Year range
1937
Most recent
1937
consumer_electronicsmechanical
Top Patents1 enriched
US 2089171· 1937
How the Frying Pan Guitar Created the Electric Guitar
Activity by Decade
1930s1
Company B
Central Investment Corp
Patents indexed
1
Year range
1973
Most recent
1973
consumer_electronicsmechanical
Top Patents1 enriched
US 3735375· 1973
How Vacuum Tubes Detect Tiny Changes in High-Resistance Sensors
Activity by Decade
1970s1
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