BALL TAKE-OUT STRUCTURE FOR TRACK BALL

摘要

PROBLEM TO BE SOLVED: To provide a ball take-out structure for a track ball, capable of taking out a ball together with a ring while keeping the entire track ball fixed to medical equipment or the like without disassembling a case and easily cleaning the ball. SOLUTION: In this structure, (1) a plurality of holding arms are provided on a circumference below the ring. Each holding arm has a projection in an inner side direction on its lower end. When plotting a virtual circle with top ends of a plurality of the projections as a part of the circumference, the virtual circumference is smaller than the maximum circumference of the ball, and (2) the holding arm has elasticity so that the virtual circumference can be made wider than the maximum circumference of the ball.