WINDING OF CONTINUOUS-CURRENT ARMATURES 259 



For quick repairs a form could be improvised with four round 

 nails or pins driven into a board, together with two corner-pieces 

 shaped step fashion out of fibre or metal, as in Fig. 296. The coil 

 when wound is of the shape shown in Fig. 297, and after leaving the 

 form it has to be " spread." This may be done by means of a 

 form constructed on the general principles illustrated in Fig. 297. 

 This form may consist of a board with two cavities into which the 



FIG. 297. Simple "Spreading" Apparatus for Armature Coils. 



FIG. 298. Coil after Spreading. 



bottom loops of the coil are inserted, and then by means of a 

 hinged spreader the top and bottom portions of the coil are swung 

 apart. The coils thus formed are of the general shape indicated 

 in Fig. 298, and in this shape the coils are then taped, after which 

 the coils are pressed into their final shape by means of a third 

 form. This is shown in Fig. 299, and consists of two blocks 

 between which the coil is pressed. 



The desire to avoid the payment of royalties under the Eickmeyer 

 patents served as an incentive toward the perfection of other form- 



