Portfolio comparison
John L. Mason vs Energy Partners Inc
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 22186· 1858
John Mason's 1858 Patent for the Mason Jar Lid
Activity by Decade
1850s1
Top Patents1 enriched
US 5346778· 1994
Boosting Fuel Cell Power for Vehicles Using Oxygen Injection
Activity by Decade
1990s1
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