American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 602
tion of the pole-clianger and polarized relay will be founddescribed in the chapter on the polar duplex. In Fig. 369 also, SB is the street signal box, in which are shown only a multiplebreak-wheel bw; a pointer f; a cylinder c, with spirally arranged projections/;the answer back bell, g; the… … POLICE PATROL SIGNAL CIRCUIT.- -SHOWING AN ARRANGEMENT FOROFFICE. ANSWER BACK SIGNAL IN CENTRAL /^,/2,/^,/*, are held, by a common support h. Above these flat contacts the cylinder cis placed. The pointer p is attached rigidly to the shaft of c. Thus, wiien thepointer is turned to the right or left…
Telegraph
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