90 



ARMATURK CONSTRUCTION 



stamp out a small notch in the inner periphery of the disc, as 

 shown in Fig. 90. This notch is sometimes punched in the 

 key-way displaced from the centre, as in Fig. 89. 



Experience will show the number of core plates of a given 

 thickness which can ultimately be pressed together per centimeter 

 of core length. Hence, when the suitable quantity has been 



FIG. 98. Assembled Armature Core of Fig. 97 with Commutator fixed. 

 Dick, Kerr & Co. 



assembled, a ventilating piece is laid on, and the assembling of 

 the core plates is resumed. When the correct total number of 

 core plates has been reached, the end flange is placed in position. 

 In the case of large armatures, such as those of Figs. 85 and 86, 

 bolts securing the two end flanges and core together may be 

 employed to draw up the core to the correct dimensions; but it is 

 preferable to obtain the necessary pressure by hydraulic power, 

 and afterwards hold the core to these dimensions by the bolts. 



