| 摘要 |
A fluid pressure operated actuating device for opening and closing a door comprises a double- acting piston 5 and cylinder 4 arrangement. The door is moved by a driven rotary spindle 16 and a screw transmission in the form of rollers 8, 9 operating in inclined slots 15, 10 in inner and outer tubes 12, 11 respectively converts linear movement of the piston into rotary movement of the spindle. The screw transmission is self-locking and in end position. Pusher means move the screw transmission out of the end position on failure of the piston and cylinder arrangement. In the end closure region, a piston rod 6 pushes against a spring plate 19 and as soon as the pressure of the working fluid under the piston 5 is relieved a compression spring 18 moves the piston rod 6 with a yoke 7 downwardly. <IMAGE> |
