| 摘要 |
PCT No. PCT/FI86/00043 Sec. 371 Date Dec. 19, 1986 Sec. 102(e) Date Dec. 19, 1986 PCT Filed Apr. 30, 1986 PCT Pub. No. WO86/06359 PCT Pub. Date Nov. 6, 1986.An electrically controlled valve apparatus includes an inlet conduit (2) for pressurized fluid, an outlet conduit (12) connected to a tank (T) and an outlet conduit (19) connected to an actuator, or cylinder (5). The valve apparatus comprises a chamber (5) connected to the inlet conduit (2) and provided with two openings (10, 11) each having operating spindles (6, 7). Pressurized fluid flows from the chamber (5) through the two openings via the outlet conduits (12, 19) onto the cylinder and into the tank, or from the cylinder into the tank according to the position of the operating spindles. The valve apparatus also comprises two throttle valves (42) for constricting conduits (52, 53; 40, 45) located between the back chambers (31, 24) of the operating spindles (6, 7) and the fluid tank (T). The operation of the throttle valves is adjusted by means of one or several electric actuators (55). The valve apparatus also comprises at least one sensor (58) for measuring the motional velocity of a lift cage, and a control unit (57), which is employed for adjusting the throttle valves, through the actuators, based on information received from the sensors so that the position of the operating spindles and the fluid flow is regulated such that the lift cage (HS) is moved in a predetermined way.
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