DS

David A. Schalk

📍 Festus, MO: #17 of 75 inventorsTop 25%
🗺 Missouri: #5,256 of 23,789 inventorsTop 25%
Overall (All Time): #1,102,311 of 4,157,543Top 30%
4
Patents All Time

Issued Patents All Time

Showing 1–4 of 4 patents

Patent #TitleCo-InventorsDate
11919553 Railroad switch position indicator — 2024-03-05
10766511 Cable driven railroad switch indicator — 2020-09-08
8695928 Railroad switch indicator with distance amplifier — 2014-04-15
7735784 Railroad switch indicator — 2010-06-15