Lillian C. Karr, US686974A
Railway Signaling Device.
Image credit: Karr, L.C. (1901)
On November 19, 1901, Lillian C. Karr patented an innovative railway signaling device designed to activate an electric signal only when a train passed over it in a specific direction. Her mechanism used a depressible bar and a suction-controlled piston system to time the signal, while preventing activation when approached from the opposite direction.
Date of Application: 20 July 1901
Date of Issuance: 19 November 1901
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Francesca Chiaradia
PhD Student in Economics
My research interests include law and economics, economics of innovation, and information economics.