American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 614
s occur in a block, the levers connected with the switch arecaused to operate a set of contacts properly enclosed, which operate the disc signal ina manner similar to that of the track instrument. Halls Electric Railway Signal for Crossings.By the aid of two track instruments, electric circuits,… … halls railway crossino signal.The interlocking magnets and circuit connections for this purpose are shown inFig. 378. m,m are ordinary electro-magnets provided with armatures a, b as sliown.One end of armature lever b of m passes through a slot e in the armature lever of m.A bar B is pivoted at the…
Telegraph
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