Patent ID: 6032416
Filing Date: 2000-03-07
Classification: B60J,E05B,E05F,E05Y

Abstract:
A door system for enabling ingress and egress of passengers into and out of a transit vehicle, said door system comprising:a first door mounted for movement in a first door closing direction to a first door closed position to at least partially cover an aperture and for movement in a first door opening direction to a first door open position to at least partially uncover such aperture, said first door opening direction being opposite to said first door closing direction;a motor;a drive means connected to said motor and to said first door for moving said first door to said first door closed position and for moving said first door to said first door open position;a second door connected to said drive means for longitudinal movement opposite to said first door, said second door moving in a second door closing direction to a second door closed position to at least partially cover such aperture when said first door moves in said first door closing direction, said second door moving in a second door opening direction to a second door open position to at least partially uncover such aperture when said first door moves in said first door opening direction, said second door closing direction being generally opposite to said first door closing direction and said second door opening direction being generally opposite to said first door opening direction, so that said first door and said second door cooperate to cover and uncover such aperture and so that longitudinal acceleration loads and longitudinal gravity loads on said first door are at least partially counterbalanced by longitudinal acceleration loads and longitudinal gravity loads on said second door, said longitudinal loads being communicated between said first door and said second door by said drive means;a door biasing means operable when said first door is in said first door closed position and said second door is in said second door closed position, said door biasing means exerting a door biasing force tending to move said first door in said first door opening direction and to move said second door in said second door opening direction, said door biasing force being communicated between said first door and said second door by said drive means;a first door lock member for locking said first door in said first door closed position, said first door lock member being moveable to a first door locking position in which it prevents opening of said first door and moveable to a first door unlocking position in which it allows opening of said first door, said first door lock member having a first lock member biasing force tending to move it towards said first door locking position;a first door unlocking actuator for moving said first door lock member from said first door locking position to said first door unlocking position;a control system for sending a first door unlocking signal to said first door unlocking actuator and for sending a door closing signal to said motor to close said first door and said second door and for sending a door opening signal to said motor to open said first door and said second door; andat least a portion of said door biasing force being reacted by said first door lock member to generate a first door lock member load on said first door lock member, said first door lock member load on said first door lock member preventing movement of said first door lock member from said first door locking position to said first door unlocking position when said motor is not energized in said door closing direction so that unlocking of said first door requires, in addition to said first door unlocking signal to said first door unlocking actuator, said door closing signal to said motor to generate a first door closing force to overcome at least a portion of said door biasing force to remove at least a portion of said first door lock member load from said first door lock member before said first door unlocking actuator is able to move said first door lock member from said first door locking position to said first door unlocking position whereby said door system cannot be unlocked by a single spurious signal to either said motor or to said first door unlocking actuator.