Portfolio comparison
John L. Mason vs DUAL PARKING METER Co
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 22186· 1858
John Mason's 1858 Patent for the Mason Jar Lid
Activity by Decade
1850s1
Top Patents1 enriched
US 2118318· 1938
How the First Coin-Operated Parking Meter Works
Activity by Decade
1930s1
How to use
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