Portfolio comparison
Sperry Gyroscope Co Inc vs William F. Semple
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 1242065· 1917
How Elmer Sperry Invented the Gyroscopic Compass for Ships
Activity by Decade
1910s1
Top Patents1 enriched
US 98304· 1869
William Semple's 1869 Patent for Improved Chewing Gum
Activity by Decade
1860s1
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