When we use our Whirlpool washer it causes the breaker switch to stop the washer. Why has it started this. We have to go out the turn the switch back on several times during the washing cycle?

You either have a bad breaker, loose connection(s) at breaker. Or problem with washer,
OR washer could be on with other loads, exceeding breaker capacity.
Swaping breaker easiest test, with out a Meter.

You either have a bad breaker or an electrical problem with unit. I would call in a tech for this repair. Unless you are very handy and have electrical experience,I would say it may be over your head and unsafe to do

How do I change a breaker switch