Inflatable ball, has bladder unit connected to valve unit and operating between inflated state and uninflated state, where inner bladder of bladder unit has percent elongation higher than percent elongation of outer bladder

摘要

The ball has a bladder unit (20) connected to a valve unit (30) with a hollow valve support seat (31) and a hollow seat return element (32), and comprising an inner bladder (22) and an outer bladder (21). The unit (20) operates between an inflated state in which the bladders have a spherical shape and the inner bladder is stopped against the outer bladder, and an uninflated state in which the bladders have a non-spherical shape and defines a space relative to each other in a co-operative manner. The inner bladder has a percent elongation higher than a percent elongation of the outer bladder.