Portfolio comparison
Theophilus Van Kannel vs TANN CO
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 387571· 1888
How the Revolving Door Was Invented
Activity by Decade
1880s1
Top Patents1 enriched
US 3351836· 1967
How Intermittent Windshield Wipers Work
Activity by Decade
1960s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.