EDITED COMMENTS: Initially, what I thought you had was a Western Flyer Cosmic Flyer, just like the one in this first picture, circa around 1966. Photo credit: Cabe member 'wrongway'. Upon closer inspection I noticed the small blade attachment on your front fender, your rear reflector, and the decals on your forks don't match a Cosmic Flyer.
The correct identity of your bike is an Otasco Flying O. They were built by Murray for Otasco (Oklahoma Tire and Safety Company). Take a close look at yours and see if the identifying features in the other pictures of a Flying O match yours.