A method of winding disc and drum armatures. It consists in lapping back
each lead of wire towards the preceding lead upon the commutator end of
the armature. Thus taking the letter U as the diagrammatical
representation of a turn of wire in connecting its ends to the
commutator bars they are brought towards each other so as to connect
with contiguous commutator bars. This carries out the principle of
keeping the two members of the U moving in regions of opposite polarity
of field, so that the currents induced in them shall have opposite
directions, thus producing a total current in one sense through the bent
wire.