90 



ELECTRICAL MACHINERY 



then the coil is impregnated, by the vacuum process, with 

 some good insulating compound. 



Fig. 49 shows several sets of such coils after they have 

 been taken from the impregnating tank some impregnated 



FIG. 50. Small Armature Partially Wound with Formed Coils. Fish 

 board insulation placed in slots before coil is pushed in. Crocker- 

 Wheeler Co. 



field coils may be seen also. Fig. 50 shows an armature 

 core which is partially wound with these formed coils. 

 In Fig. 50 can also be seen the method of preparing the 

 slots before the coil is forced into place. A sheet of 

 tough paper (fiber or fish-board) is bent into the form of a 



