BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an exercise ball, and more particularly to an exercise ball with an air layer provided between the inner bladder and a yam lining, a swaddled lining around the yam lining to strengthen the rigidity of the bladderand a sponge lining to maintain the soft feel of the surface of the ball.
2. Description of Related Art
A basketball, a volleyball, a handball or any large ball used for sports activities usually has an inner bladder and an outer rubber or leather surface mounted outside the bladder. Consequently, the hardness or softness of the ball is determinedby the air pressure inside the inner bladder. When the air pressure in the bladder is too high, the user is easily hurt by the impact of the ball. When the pressure in the bladder is too low, the ball responds sluggishly to being bounced, hit ordribbled and slows down the sporting activity. Therefore, it is quite difficult for the user to determine when the pressure inside the bladder is correct especially when there is no pressure gauge at hand to measure the pressure inside the bladder.
To overcome the shortcomings, the present invention tends to provide an improved exercise ball to mitigate and obviate the aforementioned problems.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide an exercise ball having an air layer and a sponge lining inside the ball so that the ball is able to be soft even if the pressure inside the bladder is higher than what is needed.
Another objective of the present invention is to provide a yarn lining mounted on an outer periphery of the bladder and a swaddled lining around the yarn lining, such that the rigidity of the ball is ensured.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the exercise ball in partial section showing the interior structure of the ball; and
FIG. 2 is a cross sectional view of the exercise ball in FIG. 1 showing different layers inside the ball.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1 and 2, a preferred embodiment of the exercise ball (1) in accordance with the present invention comprises a bladder (11), an air layer (12), a yarn lining (13), a cloth layer (14), an adhesive layer (16) and a surfacelayer (17).
To make the exercise ball (1), first a layer of methylbenzene solution is applied to the outer face of the bladder (11). Then a layer of yarn (13) is loosely wound on the bladder (11). After the yarn layer (13) is applied on the outer face ofthe bladder (11) to sandwich the methylbenzene solution, a cloth layer (14) is wound on the yarn layer (13) to strengthen the rigidity of the bladder (11). Thereafter, a sponge layer (15) is bonded to the cloth layer (14). After an outer surface (17)is attached to the sponge layer (15), the entire ball is vulcanized. During the vulcanization process, the methylbenzene solution sandwiched between the yam lining (13) and the bladder (11) is vaporized and thus forms an air layer (12) and the outersurface (17) made of leather or other suitable material is securely attached to the sponge layer (15).
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, thedisclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which theappended claims are expressed.
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