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. The Street railway journal . ings, which are very strong, aresecurely bolted to the cast-iron arms of the hub, and to them thepole pieces are secured also by Dolts. The pole piece has a T-shaped section and is constructed of rather thick laminae of iron,which are tightly compressed together and securely riveted, enab- The vertical division of the frame serves to hold the laminae inplace. These are exceptionally large stampings of iron, deeplynotched at proper intervals to receive the coils of the laminae in sizes up to and even exceeding 100 , consistof but a single piece
. The Street railway journal . ings, which are very strong, aresecurely bolted to the cast-iron arms of the hub, and to them thepole pieces are secured also by Dolts. The pole piece has a T-shaped section and is constructed of rather thick laminae of iron,which are tightly compressed together and securely riveted, enab- The vertical division of the frame serves to hold the laminae inplace. These are exceptionally large stampings of iron, deeplynotched at proper intervals to receive the coils of the laminae in sizes up to and even exceeding 100 , consistof but a single piece for a half circumference. They are stackedtogether with the slots coincident and with suitable separatorplates at intervals to provide for ventilation. The cast-iron halvesof the frame are cored out sufficiently to admit of an air chamberbehind the outer circumference of the laminae. The ventilatingholes in the side of the casting, which appear in the photographs,give access to the outer air. The lanihue are insulated with pa-. FIG. 4.—REVOLVING FIELD MAGNET per and a sufficient number of them are placed in the armatureframe, so that when the latter is set up by bolts parallel to theshaft they will be tightly clamped together. These bolts are neverintended to be removed, and so they are set up with great pres-sure and the ends are closely filed off to the nuts. Fig. 2, an en-graving of the lower half of an armature frame, displays its con-struction to good advantage. This frame is that of a single phasemachine and is similar in construction to those to be used at theCarbide Works. If the machine were to be two phase, there August, 1898.] STREET RAILWAY JOURNAL. 463 would be intermediate notches at 90 degs., with slots for the singlephase coils, and both sets of coils would have to be slightly bentin order to avoid each other. The coils are wound on forms and are very heavily insulated, soheavily, indeed, that there is no necessity of insulating the arma-ture core in any way;
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884