wHIRLPOOL dRYER NEEDS HELP

I Have A Whirlpool Dryer That The Heat Will Not Work After 10 Minutes Of Running. The Dryer Vent Was Full And I Cleaned That Out. I Cleaned The Back Of The Unit Also. I Think There May Be A Hi-limit Switch That May Be Out. If I Let The Dryer Set For 15 Minutes It Will Work Again For 10 Minutes And Heat Will Become Cold. Can Anyone Help?
Thanks
Wayne

turn on dryer .go out side +check for good air exhaust, also kinked venting at back of dryer,it could also be timer contact problem

Could be a bad breaker.