| 摘要 |
PURPOSE:To prevent occurrence of an accidental hazard like the falling of an elevator or other, by employing such an arrangement that a valve element disposed in a valve box in a freely slidable manner is urged onto a valve seat formed around the marginal part of a valve port by the force of a spring loaded at the back of the valve element. CONSTITUTION:When operation of a hydraulic elevator is normal, a valve element 6 in an automatic stop valve 1 is held at a poition away from a valve seat 9 by the hydraulic pressure of work oil against the force of a spring 8. Here, if some damage is caused in the hydraulic system located on the side of a hydraulic pump 19 from the automatic stop valve 1, the level of hydraulic pressure in the valve 1 is dropped drastically, so that the force of the spring 8 overcomes the hydraulic pressure. As the rsult, the valve element 6 is urged onto the valve seat 9, and outflow of work oil from a jack 13 is stopped. Thus, an elevator cage is held at the position. |
