Abstract: A tracked mobility device includes a frame, a pair of track drives connected to the frame, and a rear wheel assembly that is independent of the track drives. Each track drive has a flexible track rotating around a set of wheels, with each set of wheels including a rear powered wheel, a central weight-bearing wheel, and a front roller wheel. The wheels are fixed to the frame at a height effective to cause the track drive always to have a “V”-shaped lower surface when viewed from the side. The independent rear wheel is at a fixed and constant height with respect to the frame, with the fixed and constant height being effective to allow the rear wheel to cooperate with the lowered central portion of each of said track drives to provide a three-point contact with a flat surface.

Abstract: The present invention is a training baseball. The training baseball includes elongated fins that cause the training baseball to have a curved flight when thrown in a straight-throw motion. The present invention also includes a method for using the training baseball.

Abstract: A combination ball marker and stroke indicator device (10,20) has a first disc member (12,22) having a ground piercing pin (12b,22b) extending from a bottom face surface rotatably received through a pin receiving aperture (14a,24a) in a second disc member (14,24). Stroke indicating indicia (14b) are arranged on the top face surface of the second disc member and selectively alignable with a window (12a,22a) formed in the first disc member. A ground traction surface configuration (24e,24e′,24e″) is preferably formed on the bottom face surface of the second disc member. An annular recess (22d) may be formed in one of the disc members, for example, in the bottom face surface of the second disc member, to provide clearance between the indicia on the second disc member and the facing surface of the first disc member.

Abstract: A combination ball marker and stroke indicator device (10, 20) has a first disc member (12, 22) having a ground piercing pin (12b, 22b) extending from a bottom face surface rotatably received through a pin receiving aperture (14a, 24a) in a second disc member (14, 24). Stroke indicating indicia (14b) are arranged on the top face surface of the second disc member and selectively alignable with a window (12a, 22a) formed in the first disc member. A ground traction surface configuration (24e, 24e′, 24e″) is preferably formed on the bottom face surface of the second disc member. An annular recess (22d) may be formed in one of the disc members, for example, in the bottom face surface of the second disc member, to provide clearance between the indicia on the second disc member and the facing surface of the first disc member.