Patent ID: 8393981

Claim:
A device for modifying the travel of a strikeable object, comprising: a suspension line configured for attaching said device to an external anchor; a sail configured for producing aerodynamic resistance, said sail having a first end, a second end, a first side and a second side, said first end of said sail being connected to said suspension line; a spreader, said spreader configured for maintaining a preferred distance between said first side of said sail and said second side of said sail; an adjustable aperture passing through said sail from a front surface of said sail to a back surface of said sail, said adjustable aperture configured to be selectively opened to decrease said aerodynamic resistance produced by said sail and selectively closed to increase said aerodynamic resistance produced by said sail; and a strikeable object coupled to said second end of said sail; wherein, when said strikeable object is in a rest position, said device is vertically suspended from the external anchor by said suspension line, with said strikeable object suspended below said sail; wherein, when said strikeable object is set in motion, aerodynamic resistance produced by said sail reduces the speed and distance traveled by said strikeable object; and wherein, when said strikeable object reaches a limit of travel, said strikeable object returns to said rest position due to a weight of said strikeable object, and aerodynamic resistance produced by said sail reduces the speed of the return of said strikeable object to said rest position.