| 摘要 |
<p>PURPOSE: To take a track ball out of a case only by removing a ring for supporting the ball to freely rotate it, and to clean the inside of the case by making the ring freely attachable and detachable to the case. CONSTITUTION: A base part 1 is almost box-shaped as a whole and opens the upper part, a cover 3 having a circular hole 1 is integrally fitted onto this base part 1, and a case 5 is composed of the base part 1 and the cover 3. A ball 13 provided inside the case so as to be freely rotated is interlocked in contact with rotary detection plates 11 and 12. One part of the ball 13 is exposed from the circular hole 2 to the outside and with a screw part 2A of the circular hole 2, a ring screw part 3Aa of a ring 3A is screwed. The ball 13 is provided so as not to get out of the circular hole but to be freely rotated. Since one part of the ball 13 is a little protruded from the ring 3A as well, when the ring 3A is removed from the cover 3 of the case 5, the ball 13 can be easily removed from the case 5.</p> |
