Portfolio comparison
Elias Howe vs Theophilus Van Kannel
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 4750· 1846
How Elias Howe Invented the Modern Lockstitch Sewing Machine
Activity by Decade
1840s1
Top Patents1 enriched
US 387571· 1888
How the Revolving Door Was Invented
Activity by Decade
1880s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.