Commutator design for commutator fusing

One of the biggest problems encountered in the production of universal or D.C. electric motors has been the method and practice of joining the armature's coil wires to the commutator. For years most manufactuers either soft soldered or brazed the coil wires to the commutator. This was fairly acceptable before 1950, when electric motor production was quite low. As consumer demand increased for low cost, reliable and safe motors, to be used in household appliances and automotive applications, most manufacturers realized that the only way to eliminate the problems encountered with soft soldering or brazing was through commutator fusing.