Portfolio comparison
Theophilus Van Kannel vs Research Corp
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 1948384· 1934
How Ernest Lawrence Invented the Cyclotron Particle Accelerator
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.