Portfolio comparison
Almon B. Strowger vs Theophilus Van Kannel
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 447918· 1891
How Almon Strowger Invented the Automatic Telephone Switch
Activity by Decade
1890s1
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.