| 摘要 |
A door operator for opening and closing doors on transit vehicles and the like includes an actuator (50) secured to the transit vehicle (10). The actuator houses a worm drive and a reciprocating air cylinder (52) for imparting rectilinear motion to the worm drive. A door shaft (18) is coupled to a door (14) and mechanically coupled to the worm drive such that rectilinear motion of the system is transmitted by the worm drive into rotary motion to the drive shaft to open and close the door. A cam (90) is secured to the vehicle and adjacent to a cam follower (108) that is secured to the door shaft. The cam follower engages the cam during approximately the initial 80% motion during closing of the door and approximately the final 80% of the door opening. A recycling switch (200) for the door may be mounted in the vehicle adjacent to the cam in a position to be engaged upon engagement of the door with an object to recycle the door. |
