A non-spherical object that responds on impact and rebounds as a spherical ball of a size ranging from one to twelve inches in length and weighing approximately one pound to three pounds in weight.

An inflatable sport ball, such as a basketball, a football, a soccer ball, a volley ball or a playground ball, is provided with self-contained inflation means for inflating or more likely adding pressure to the ball. The inflation means is a vessel inside of the ball containing a high pressure gas which may be bled form the vessel into the interior of the ball surrounding the vessel such as by valve means operable from the outside of the ball.

A cat toy comprised of at least a partially transparent and generally spherical hollow external ball within which a second smaller opaque ball is suspended so as to form a uniform continuous gap between the two balls. The external ball is provided with an opening through which small balls having diameters only slightly smaller than the height of the gap may be inserted or removed from the gap. The opening is normally covered by a removable section. The external ball is also provided with at least one access opening having a diameter smaller than the diameter of the small balls but large enough to allow a cat to insert a single cat paw there through in order to bat at the small balls.

A dual-bladder inflatable ball includes: a valve unit; an outer cover defining a confining chamber therein and connected sealingly to the valve unit; a bladder unit enclosed in the confining chamber in the outer cover, connected to the valve unit, and including an inner bladder and an outer bladder enclosing the inner bladder and disposed between the outer cover and the inner bladder. The bladder unit is operable between an inflated state, where the inner and outer bladders are spherical in shape and the inner bladder abuts against the outer bladder, and a deflated state, where the inner and outer bladders are non-spherical in shape and cooperatively define a gap therebetween. The outer bladder has a first elongation percentage, and the inner bladder has a second elongation percentage greater than the first elongation percentage of the outer bladder.

A variable-weight ball that is particularly useful for the development of motor skills in children of all ages is disclosed. A first inflatable bladder filled with a first gas and a second inflatable bladder filled with a second gas are disposed within an outer casing. The relative weight of the ball can be adjusted by using gases of different densities in the first and second bladders and by adjusting the amount of gas in each bladder.