Manual and motor actuated railway car door

A sliding door for railroad cars comprising:

• (a) a horizontal support member fixed on the car and on which the door is reciprocably slidably operable between open and closed positions;
• (b) a pneumatically operable cylinder device including a piston reciprocably operable therein and separating front and rear pressure chambers in the cylinder device;
• (c) a piston rod connected to said piston and having a free end extending exteriorly of the cylinder device, said cylinder device being arranged on said support member longitudinally parallel to the direction of travel of the door;
• (d) a catch device carried by the door and including a first catch element so positioned as to be engageable by a second catch element carried by the free end of the rod, said catch elements cooperating with each other for effecting power operation of the door by the cylinder device during closing and emergency opening of the door;
• (e) an electropneumatic control circuit operable, when energized, for effecting pressurization of the rear pressure chamber of the cylinder device and consequently extension of the piston rod from a retracted position in the cylinder devices to an extended position thereoutof in which said first and second catch elements abuttingly engage, upon a predetermined distance of travel of the rod out of the cylinder device, to effect consequent operation of the door from its said open position toward its said closed position;
• (f) first release means operably associated with said catch device and operable for disengaging said first and second catch elements when the door has reached a certain predetermined distance from its closed position;
• (g) a lock mechanism carried by the door adjacent the upper leading edge thereof and automatically operable, upon attainment of the closing position of the door, for locking said door in its said closed position until manually released;
• and
• (h) a normally closed electrical switch carried on the door operably connected to said lock mechanism and operable in the closed position of the door to an open position in which the electropneumatic control circuit is deenergized, said control circuit being effective, when deenergized, for venting said rear pressure chamber to atmosphere and pressurizing the front chamber for causing operation of the cylinder device and consequent retraction of the piston rod.