Portfolio comparison
Marvin C. Stone vs DUAL PARKING METER Co
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 375962· 1888
How the Modern Paper Drinking Straw Was Invented
Activity by Decade
1880s1
Top Patents1 enriched
US 2118318· 1938
How the First Coin-Operated Parking Meter Works
Activity by Decade
1930s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.