| 摘要 |
<p>PROBLEM TO BE SOLVED: To remove dust or the like existent between a ball inside a case and a detection shaft or the like without disassembling the case by providing an opening formed on the side part or the bottom part of the case. SOLUTION: Inside a round hole 1b formed on an upper face 1a of a case 1, a ball 2 is provided so as to be freely rotated. Inside the case 1, two detection shafts 3 and 4 are provided so as to be freely rotated. At a side part 1c of this case 1, an opening 7 is formed and from this opening 7, the dust or the like stuck on the surface of the ball 2 and the detection shafts 3 and 4 is removed by a hand or by a brush, etc. Besides, the place to form the opening 7 is not limited only at the side part 1c of the case 1 but even when it is formed on a bottom part 1d, the similar operation is provided. Therefore, the inside is extremely easily maintained/cleaned through the opening 7 without disassembling the case 1.</p> |
