US Patent 8210970 Expandable arrow broadhead with rotating cutting blades and shaft

An expandable arrow broadhead used for releasable attachment to one end of a hollow arrow shaft. The broadhead includes a rotating, sliding shaft with a spirally wound, scalloped grooved, pointed tip and tip base having two or more of cutting blades mounted thereon. A portion of the sliding shaft is slidably received inside a hollow collar attached to a sliding shaft housing. The sliding shaft housing is attached to an arrow shaft insert adapted for receipt inside one end of the arrow shaft. In a retracted position, the blades are disposed next to and parallel to the length of the sliding shaft. When the pointed tip engages a target, the sliding shaft moves inwardly and rearwardly sliding inside the collar. As the sliding shaft moves rearwardly, a beveled cam surface of the blades engages a portion of the collar, which moves the blades outwardly in an extended and locked position.