| 摘要 |
A plug door 1 for a vehicle such as a railway carriage, is carried and driven by a swinging lever 9 which has a sliding fulcrum mechanism 12 the effect of which is to flatten the arc through which the door is carried. The edge of the door which trails in an opening movement is guided either by means of a relatively long pivot arm 19 or by a curved or straight track. The alternative guide means give different trajectories to the leading edge of the door, and all require much less room than known swinging plug doors. The long pivot arm guide keeps the door closest to the side of the vehicle during opening. A duplicate swinging lever with sliding fulcrum mechanism as a guide for the trailing edge will move the door parallel to the side of the vehicle and the sliding fulcrums will substantially reduce the outward excursion. By mounting the driving swinging lever 9 over-centre, i.e. closer to the trailing edge of the door the plug action is provided for so that a closed door may be flush with the vehicle. In an alternative embodiment (Fig. 2, not shown) a double plug door arrangement is disclosed which is operated by a pneumatic cylinder. <IMAGE> |
