I have no clue where you are going with this. Attached is a drawing of the early style bell I believe you are referring to. If you look at the pole of the electromagnet labeled S you can see how when power is applied the contacts make and break over and over again. It is basically an electro mechanical vibrator action. The switching is automatic.
What exactly are you trying to do?
If you just want to drive a pair of series coils, reversing polarity at some rate, consider using an H bridge circuit.
Ron