Portfolio comparison
DUAL PARKING METER Co vs Standard Oil Co
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 2118318· 1938
How the First Coin-Operated Parking Meter Works
Activity by Decade
1930s1
Top Patents1 enriched
US 1049667· 1913
How William Burton Invented Modern Gasoline Refining
Activity by Decade
1910s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.