| 摘要 |
<p>PURPOSE:To completely shut out the intrusion of seawater or the like by covering a cup-shaped bellows formed of elastic members from the upper face of a track ball over the upper face of a housing so that a clearance can be held. CONSTITUTION:A waterproof cover 10 of a track ball 2 is equipped with a cup-shaped bellows 12 formed of the elastic members, and the bellows 12 is covered from the upper face of the ball over the upper face of the housing so that a clearance epsilon can be held. Then, plural projecting parts are provided at the lower face of the top part of the bellows 12. And also, the bellows 12 are formed of the transparent elastic members. Therefore, the cup-shaped bellows 12 formed of the elastic members covered over the ball 2, waterproofs the entire track ball 2, and it is easily transformed by the tip of a finger, and also by the movement of the ball 2, and quickly recovered to the original position where the clearance epsilon can be held when the finger is detached. Then, the plural projecting parts provided at the lower face of the top part of the bellows 12, can reduce a contact part with the ball 2, and prevent the adhesion to the ball 2, and the transparent bellows allows the ball 2 to be seen.</p> |
