公开(公告)号：EP0708250A2

公开(公告)日：1996-04-24

申请号：EP95307093.5

申请日：1995-10-06

申请人： Smiths Industries Public Limited Company

发明人： Davies, Anthony Roger ,  Wallace, Michael John ,  Downward, Stephen James

IPC分类号： F15B11/04 ,  B66B1/04

CPC分类号： B66B1/24 ,  F15B11/048 ,  F15B2211/20515 ,  F15B2211/27 ,  F15B2211/30505 ,  F15B2211/31529 ,  F15B2211/40576 ,  F15B2211/413 ,  F15B2211/41581 ,  F15B2211/426 ,  F15B2211/465 ,  F15B2211/6336 ,  F15B2211/665 ,  F15B2211/6651 ,  F15B2211/6654 ,  F15B2211/7052 ,  F15B2211/755

摘要： An hydraulic lift system has an actuator 2 connected to an hydraulic circuit, having a pump 31, via a supply line 20. A balanced seated valve 50 is connected between the supply line 20 and a reservoir 33, the valve being controlled by a solenoid 51 and an electric drive unit 40. The drive unit 40 supplies a gradually increasing or decreasing voltage to the solenoid 51 to open or close the valve 50 gradually. The valve has a valve member 170 that is displaceable along its length and has a valve head 174 of frusto-conical shape. A passage 176 along the valve member 170 balances fluid pressure across the valve member. The solenoid 51 has an armature 160 with a pole face 161 that can be displaced towards a fixed pole face 167 to unseat the valve member 170. The pole faces 161 and 167 have complementary frusto-conical surfaces 163 and there is a non-magnetic washer 168 between them.