| 摘要 |
PURPOSE:To secure a tallet at a standstill during works by shortening the time for indexing through incorporation of such as arrangement that a reversible tallet is rotated at a high speed in its initial period of rotation and at a low speed immediately before stopping and that a restriction pin finally comes in engagement with the groove in a restriction pin. CONSTITUTION:When a tallet is rotated, a selector valve 63 is operated to send pressure oil to an oil pressure chamber 35. When a switch 61 senses that the tallet shaft 9 has made a leftwise shift, Either solenoid of a reversible selector valve 65 is energized to actuate an oil pressure motor 51 into high speed rotation for rotation of the tallet shaft. The selector valve 63 is deenergized immediately before stopping and the drain from the oil pressure motor 51 is changed over to small rate of flow to give the tallet a low speed of revolutions. At the same time, the pilot pressure is applied to a port 2 of an automatic spool valve 69 to shift the spool 41 leftwise, and then a restriction pin at the tip of the spool 41 comes in engagement with the groove in a restriction gear to fix the tallet. |
