Patent ID: 7604578

Claim:
An adjustable dumbbell system comprising: a dumbbell having a handle having opposed ends and a central extent, a grip rotationally receiving the central extent of the handle, an adjustment wheel secured to each end of the handle, a side cover fixedly secured to each end of the grip, a dowel disk on the handle adjacent to one side cover with fingers and spaces, a plurality of cam bits supported on the handle; a safety lock within the side cover adjacent to the dowel disk, the safety lock having a first end extent and a second end extent with a radial recess and a central extent with an axial projection, a coil spring within the radial recess urging the safety lock radially outwardly; and a plurality of weights, one weight for each cam bit, each weight having openings and each cam bit having a cam surface whereby the weights are adapted to attach to and release from an associated cam bit as a function of the rotational orientation of the shaft and adjustment wheels, each weight having a central primary aperture and primary slot, each weight having a major section and an axially offset secondary minor section, the minor section being formed with a secondary aperture and a secondary slot and wherein each cam plate includes an irregularly shaped polygon with radially enlarged sections providing cam surfaces at maximum radii greater than the radii of the remainder of the cam bit, the radially enlarged sections adapted to releasably couple selectively with the secondary aperture of the weights.