Portfolio comparison
Walter Hunt vs DUAL PARKING METER Co
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 6281· 1849
How Walter Hunt Invented the Modern Safety Pin
Activity by Decade
1840s1
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.