WINDING OF CONTINUOUS-CURRENT ARMATURES 261 



wound coils, such as the barrel type or diamond-shaped coils. 

 With coils of these types, supporting end flanges were added to 

 the armature core construction. 



These coils could he wound in a simple form of some such 

 type as that indicated in Fig. 300. The central elongated- 

 formed block of wood in Fig. 300 is provided with holes for the 

 reception of two bolts with wing nuts which clamp the central 

 block between two side blocks. The central block and side blocks 



FIG. 302. Simple Hand-spreading Apparatus. 



are so recessed as to provide spaces for a number of lead or soft 

 iron strips which are laid in place prior to winding the coil. After 

 winding the coil the lead strips are bent up over the coil, which 

 thus remains held in shape after removing it from the form. At 

 this stage the coil presents the appearance indicated in Fig. 301. 



Fig. 302 illustrates a simple way by which it may be next spread 

 out to a so-called diamond-shaped coil. The apparatus consists 

 simply of a wooden dummy of the same diameter as the armature, 

 and having one slot into which one side of the coil is placed ; the 

 other side is taken into the groove in a piece of wood, with handles 

 at each end, which is pulled round on the surface of the dummy 



