| 摘要 |
PURPOSE:To shift a horizontal wheel shaft to a turning position with a simple construction by providing an actuator which moves said horizontal wheel shaft in a horizontal direction and shift its crossing position with a vertical shaft with which a wheel supporting body rotates, on a machine body side which supports said wheel supporting body. CONSTITUTION:A wheel supporting body 6 on which a vertical shaft 7 is rotatably supported via a bearings 3, 4, are provided on a machine body 1. And, a pair of wheels 9 while rotate around a horizontal wheel shaft 8, are supported by the wheel supporting body 6, while the horizontal wheel shaft 8 is supported by supporting links 12a, 12b of a linear link mechanism 11 through a pair of long holes 10. A wheel shaft forcibly shifting mechanism 18 which is operated by a sliding rod 17 which slides in the vertical shaft 7 of the wheel supporting body 6, is used to drive the link mechanism 11. And, an actuator 25 which makes a sliding rod 17 slide in the axial direction, is provided on a machine body 1 side which rotatably supports the vertical shaft 7. Thereby, a power transmitting means to the actuator 25 can be simplified. |
