SummaryA 3D model of U.S. Pat. No. 804,585. Cutting edge 1905 door stop technology from the original Thingiverseâ€”the U.S. PTO. "To all whom it may concern: Be it known that I, HAROLD T> DEPUE, a citizen of the United States, and a resident of Kensington, in the county of Montgomery and State of Maryland, have invented certain new and useful Improvements in Door-Stops, of which the following is a specification."