. Railway age . is unenergized. andthis condition only obtains when the brushes 1 and 2 are not short-circuited. When the brushes are on a metallic bar, say A, there-fore, the bell is silent, but as soon as they pass off the bars it com-mences to ring. In addition to passing through the electromagnets A and C, asdescribed, the current to the brush 1 passes through the springsc (l\ and c^ d, each pair of which is normally in contact Thesesprings are opened by the raising of the armatures of D and Drespectively. Opening the circuit at either c V of c eT obviouslyreleases the armature of A-, and,
. Railway age . is unenergized. andthis condition only obtains when the brushes 1 and 2 are not short-circuited. When the brushes are on a metallic bar, say A, there-fore, the bell is silent, but as soon as they pass off the bars it com-mences to ring. In addition to passing through the electromagnets A and C, asdescribed, the current to the brush 1 passes through the springsc (l\ and c^ d, each pair of which is normally in contact Thesesprings are opened by the raising of the armatures of D and Drespectively. Opening the circuit at either c V of c eT obviouslyreleases the armature of A-, and, as a consequence, stops the ring-ing of the bell and lowers the semaphore arm. Currents passing through D are collected from the line hy thebrush 2, currents passing through D are collected from the line byone or the other of the brushes 3 and 4. Between the poles of I) .md D are placed magnetized n. pivoted to imn iimlfr iln- iiolariiy of the poles when the eb-ctro 1 i —-1 mrk Iij,^* u . ~^^^^x^^. Fig. 4—Brushes. Fig. 2—Apparatus in Cab of Engine. magnets are energized. The spindles carry the pointers shown InFig. 1. Each spindle also carries a small metal sector, slotted asshown by Figs. 9 and 5, in which rides a small metallic loop, piv-oted at the other end. The passage of a current through, say, Ddeflects the needle to one side, and the loop drops into a recess atthe end of the slot and locks the needle and pointeir on the frontof the instrument in the deflected position. At the same time thatthis occurs the lifting of the armature of D breaks the contact c lowers the semaphore arm and stops the bell as already stated. Auxiliary Apparatus on i)nginc.—The engine carries, in addi-tion to the apparatus described, two rotary switches, the arrange-ment of which is shown in Fig. 6. Each switch consists of a ca-st-steel wheel free to rotate, the spindle of which carries a two-partcommutator, on which bear two springs. The wheel is weighted soas to tjike
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Keywords: ., bookcentury1800, bookdecade1870, bookidrailwayage44, bookyear1870
