| 摘要 |
PURPOSE:To make a backup ball unessential and, what is more, secure a large output, by using an oil chamber filled with oil. CONSTITUTION:A ball caster 1 is fitted with a ball 2 rotatable at the inside of its body 3 via a backup ring 4 and an O-ring 5. At the inner part of the body 3, an intermediate body 6 with an arc-shaped face to the circumferential face of the ball 2 is screwed in at the inside of the body 3 movably for vertical motion via the backup ring 4 and the O-ring 5 and an arc-shaped oil chamber 7 is set in between the intermediate body 6 and the ball 2. In addition, at the center of the intermediate body 6, there is provided with an inner hole 8 leading into the oil chamber 7 and a blind plug 10 is set in the bottommost part of an oil filler port 9. |
