摘要 |
A rail house car with side openings and doors for closing the openings by movement of the doors longitudinally along the car sides and laterally into and out of the openings. Cranks moveably support and retain the doors on longitudinal tracks below the doors and within longitudinal retainers above the doors. The cranks are selectively manually driven for lateral movement of the doors. The top cranks include combination skid and roller devices which permit the doors to move easily because of the rollers when they are longitudinally moved along the track and retainer but which permit the locating of the rollers within recesses in the surfaces of the retainers when the doors are located laterally substantially within their openings along the car sides. The skids provide minimal wear of the surfaces of the retainers when the doors are so located because of the relatively large areas of the skid surfaces in face to face engagement with the retainers' surface portions adjacent the recesses as compared to wear normally created by the rollers' tangential lines of contact with the retainers' surfaces. This wear is usually present in those situations where insufficient structural support for the roof causes vertical vibrations in the longitudinal retainers. The skid and roller combination is also associated with any auxiliary cranks which are in engagement with surfaces of the longitudinal retainers. |