Black American inventionIn 1888, a U.S. patent was issued for the railway signal to the Black American inventor, A.B. Blackburn (No. 376,362). The type of signal was that designed to be operated by the wheels of a train. A lever was depressed as a train wheel travelled over it, to remotely operate an alert through a mechanical linkage upon the passing of the train. It was designed for use upon a single track railway line for trains passing in one direction. To provide a signal for trains passing in the opposite direction, a similar apparatus would be applied on the opposite rail. This patent was an improvement in mechanical design of his earlier patent No. 309,517 on 23 Dec 1884, in which he also described how a gong was activated to provide the alert.«[Image: detail from patent diagram showinf device beside a section of rail.] |
