ARMATURE WINDINGS. 425 



an element of the winding. If we now continue from commu- 

 tator segment No. 2 along inductor No. 3, across the back to in- 

 ductor No. 8, and thence along inductor No. 8 to commutator 

 segment No. 3, we shall have completed the second element of 

 the winding. The rest of "the winding is merely a repetition of 

 the steps just described. It is evident from Figs. 52 and 53, 

 that each winding element consists of an almost closed loop or 

 coil, and that the second element laps over the first, as shown by 

 the heavy lines in Figs. 52 and 53. It is on account of this over- 

 lapping of the elements that this winding is called the lap winding. 



In Figs. 52 and 53 it can be seen that inductor No. I is con- 

 nected at the back to inductor No. 6, inductor No. 3 to No. 8 ; 

 inductor No. 5 to No. 10; and so on, that is, each odd num- 

 bered inductor is connected to the fifth following inductor. This 

 interval between inductors connected at the back end of the 

 armature is called the back pitch of the winding and it is equal to 

 5 in Figs. 52 and 53. In this same figure it can be seen that 

 inductor No. I starts from segment No. I, and that inductor 

 No. 4 is also connected to segment No. I, and in a similar man- 

 ner inductors Nos. 3 and 6 are both connected on the front end 

 to segment No. 2, and so on. This interval between inductors 

 connected together at the front end is called fas front pitch of the 

 winding, and it is equal to 3 in Figs. 52 and 53. 



In tracing through the winding in Figs. 52 and 53, one pro- 

 gresses in one direction at the back, and in the opposite direction 

 at the front of the armature, and therefore one pitch, say the 

 back pitch, is considered positive and the other pitch is consid- 

 ered negative. 



In Figs. 52 and 53 the terminals of an element of the winding 

 are connected to adjacent commutator segments, and the wind- 

 ing is called a simplex or single lap winding. 



In what is called a duplex or double lap winding the terminals 

 of an element of the winding are connected, not to adjacent com- 

 mutator segments, but to every other segment. In what is called 

 a triplex or triple lap winding the terminals of an element of the 



