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| Number | Title | Issue Date |
| 5144895 | Hopper door apparatus for a railway car A door apparatus for a railway hopper car for discharging bulk material from the car has an elongated flexible hollow body positioned in a discharge opening. A pair of end walls are attached to opposite ends of the body. Each end wall has a first pivot po... | 09/08/1992 |
| 5115748 | Hopper door and operating apparatus for a railway car A door and operating apparatus for railway hopper cars includes a door having a first pivot point for rotary attachment to the hopper. A second pivot point is formed on the door and a cross beam is positioned adjacent to the door for movement in a vertica... | 05/26/1992 |
| 4493266 | Railway hopper car and center sill construction therefor A railway hopper car has a through center sill including an elongated central section substantially A-shaped in transverse cross section, two end sections substantially hat-shaped in transverse cross section and two transition sections respectively connec... | 01/15/1985 |
