Patent ID: 7147580

Claim:
A warm-up bat comprising: a tubular shell with a handle section, a barrel section, and a tapered section connecting the handle section with the barrel section; a handle attached at an end of the handle section of the bat; an end cap attached to an end of the barrel section of the bat opposite said tapered section; a sliding weight mechanism; said sliding weight mechanism being entirely contained within the barrel section of the bat, and positioned within the barrel section of the bat; said sliding weight mechanism comprising: an elongated shaft having a first end and a second end, said shaft first end affixed to said end cap, said shaft extending within the barrel section of said bat and terminating at said second end, said second end being located proximate to said tapered section of said bat; a magnet affixed to the second end of said shaft by a bolt extending through said magnet and axially engaging said shaft second end; a foam ball positioned on said shaft, said foam ball being located adjacent to said end capt; and a magnetically attractable weight slidably supported on said shaft by at least one bushing disposed between said weight and said shaft, said weight being slidable along said shaft from said magnet to said foam ball; wherein said weight is configured for being held by the magnet until a predetermined amount of force is applied to the weight through a swing of the bat, whereby the force of the magnet is overcome allowing the weight to slide on the shaft.