Locking and unlocking apparatus for access door on a passenger railway vehicle

An apparatus for mechanically locking and unlocking a passenger access door panel on a railway vehicle, said apparatus comprising:

• (a) a movable door panel disposed in a generally vertical plane and adapted for opening and closing movement in a generally horizontal plane of movement;
• (b) a locking lever arm having a first end pivotally secured to a first of said movable door panel and a structure adjacent said movable door panel, and having a roller rotatably secured to a second end, said locking lever arm pivotally secured such that pivotal movement of said locking lever arm will cause said roller to move in an arc generally perpendicular to said horizontal plane of movement;
• (c) a biasing means to pivotally bias said locking lever arm about said first end, such that said roller is biased in a biasing direction generally perpendicular to said horizontal plane of movement;
• (d) a locking support structure secured to a second of said movable door panel and said structure adjacent said movable door panel, said locking support structure having a first rail surface portion at least a part of which is at an inclined angle to said horizontal plane of movement, and a second rail surface portion substantially perpendicular to said horizontal plane of movement, such that said first and second rail surface portions intersect and form a rail surface intersection;
• the relative positions of said locking lever arm and said locking support structure being such that when said door panel is moved towards a closed position, said roller on said locking lever arm is caused to engage and roll along said first rail surface portion towards said rail surface intersection, and such that when said roller is rolling along said part of said first rail surface portion that is at an inclined angle to said horizontal plane of movement, said locking lever arm is caused to be pivoted in a direction opposite to said biasing direction caused by said biasing means, and such that when said door panel reaches a fully closed position, said roller will have rolled beyond said rail surface intersection, so that said locking lever arm is biased by said biasing means sufficient to pivot said roller to a position adjacent to said second rail surface portion to thereby lock said door panel in said fully closed position;
• (e) means for automatically pivoting said locking lever arm in a direction opposite to said biasing direction of said biasing means and away from said locking support structure to thereby unlock said door panel;
• and
• (f) means for manually pivoting said locking lever arm in a direction opposite to said biasing direction of said biasing means and away from said locking support structure to thereby unlock said door panel.