Factory and industrial management . is to enable axles,when on curves, to de-part freely from theirnormal parallelism in re-spect to the transversealinement of the framesand as caused by thesuper-compression of thesprings due to the super-elevation of the outer railand to the centrifugalforce, at high speed, act-i n g against the outerrail. Ordinary axle boxestend to maintain the axle parallel with the transverse line ofthe frames and with the tendency to strain the axle-box guides andframes, as also to cause undue pressure at one extremity or the otherof the journal and brass. Plate frames ha
Factory and industrial management . is to enable axles,when on curves, to de-part freely from theirnormal parallelism in re-spect to the transversealinement of the framesand as caused by thesuper-compression of thesprings due to the super-elevation of the outer railand to the centrifugalforce, at high speed, act-i n g against the outerrail. Ordinary axle boxestend to maintain the axle parallel with the transverse line ofthe frames and with the tendency to strain the axle-box guides andframes, as also to cause undue pressure at one extremity or the otherof the journal and brass. Plate frames have frequently been brokenin service on short-radius curves, the break being attributable to thisaction, which is completely avoided in these oscillating axle boxes. Another improvement by Giuseppe Zara, designer of the new Ital-ian locomotives and of the electromotor trucks of the Italian rail-ways, is the tri-phasic action throttle valve shown in Figure is really a safety device to prevent the ordinary equilibrated throttle. FIG. 29. ZAKA OSCILLATING AXLE BOX. 712 THE ENGINEERING MAGAZINE. valve from opening of itself, or by accident. To avoid such possibil-ity it is usual to fit the lliroltle handle with a latch as shown in Figure7, in June. Briefly explained, the throttle is fitted with a pilotvalve, which may be inside the main valve or fitted outside of thesteam pipe, the opening of which requires but little effort. Closed,the whole pressure of the steam holds the main valve down to itsseat, but the pilot valve admits steam below a loosely fitting cylindricalportion of the main valve, and then part of the steam relieves thel^ressure on the main valve and part of it passes around the outside of the cylindrical valve andescapes to the cylinders socommencing the firstperiod of pressure on thepistons; at this momentthe drop-seat valve at thehead of the throttle islifted from its coned seat-ing and the second periodof pressure is begun; thesectional area of the opening co
Size: 1449px × 1724px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubj, booksubjectengineering
