David A. Schalk

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Festus, MO, US

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Patents Grantslast 30 patents

Information Patent Grant
Railroad switch position indicator
- Patent number 11,919,553
- Issue date Mar 5, 2024
- David A. Schalk
- B61 - RAILWAYS
Information Patent Grant
Cable driven railroad switch indicator
- Patent number 10,766,511
- Issue date Sep 8, 2020
- David A. Schalk
- B61 - RAILWAYS
Information Patent Grant
Railroad switch indicator with distance amplifier
- Patent number 8,695,928
- Issue date Apr 15, 2014
- David A. Schalk
- B61 - RAILWAYS
Information Patent Grant
Railroad switch indicator
- Patent number 7,735,784
- Issue date Jun 15, 2010
- David A. Schalk
- B61 - RAILWAYS

Patents Applicationslast 30 patents

Information Patent Application
CABLE DRIVEN RAILROAD SWITCH INDICATOR
- Publication number 20180201283
- Publication date Jul 19, 2018
- DAVID A. SCHALK
- B61 - RAILWAYS
Information Patent Application
Railroad Switch Indicator
- Publication number 20080302921
- Publication date Dec 11, 2008
- David A. Schalk
- B61 - RAILWAYS