PORTABLE APPARATUS AND TRACK BALL USED FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a track ball that allows a user to replace a ball easily by himself/herself to meet the user's taste without causing any trouble in operability such as a positional shift of the main body by the replacement.

SOLUTION: A cover 51 of the main body 42 of the track ball has a central hole 52 larger in diameter than the ball 61, so that only the ball 61 is removable. A lower cylinder part 73 is provided for a pressing lid 71 having a circular hole 72 for preventing the ball 61 from slipping off upward. The lower cylinder part 73 is engaged with an inner edge of the central hole 52 of the cover 51 to correct the position of the main body 42 in the horizontal direction. It is thereby possible to maintain satisfactory operability without misalignment of the ball 61 with respect to the main body 42 even if the ball 61 is replaced.

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