In a hopper outlet gate assembly for bulk material carrying railroad hopper cars in which the car hopper has an outlet opening, with the assembly including a frame forming an outlet port of quadrilateral configuration, a door plate of quadrilateral configuration for closing the port, a slideway for the door plate, which slideway extends in a substantially horizontal plane sidewise and across the outlet port, with the door plate defining opposed side edge portions that parallel the slideway and define the width of the door plate, and gear and rack means for moving the door plate longitudinally of the slideway between a first position in which it is disposed across the port to close same and a second position in which it is disposed to one side of the port to open same for discharge of the bulk materials therefrom,
- the improvement wherein said frame comprises:
- a pair of spaced apart parallel longitudinal frame members paralleling the slideway,
- a pair of spaced apart parallel transverse frame members fixed between said longitudinal frame members to form the outlet port,
- said frame members being formed to each define a shelf portion on which the door plate rides,
- said frame member shelf portions being in substantial coplanar relation and being coplanar with the slideway,
- with the door plate side edge portions riding on the shelf portions of said longitudinal frame members, respectively, in sliding relation thereto,
- and with the slideway having a centerline extending longitudinally thereof that is centered between said longitudinal frame member shelf portions,
- said longitudinal frame members projecting laterally of the port from one side of the port beyond one of said transverse members,
- a bridge member fixed between said longitudinal frame members above and spaced from said one transverse member,
- said bridge member defining a header portion overlying said one transverse member shelf portion in closely spaced relation thereto to define a window opening through which the slideway extends and in which said door plate is mounted in closely spaced relation to said header portion,
- said door plate being proportioned lengthwise of said slideway to project exteriorly of the assembly through the window opening to define an outwardly projecting portion thereof when said door plate is in its first position,
- said gear and rack means comprising:
- a shaft journalled in said frame below the slideway and adjacent said bridge member, and extending crosswise of the slideway and paralleling said transverse frame members,
- and a pair of gear and rack sets coupling said shaft to said door plate for translating rotational movement of said shaft into linear movement of said door plate between said positions,
- said gear and rack sets each comprising:
- an elongate plate member fixed to the underside of said door plate and extending longitudinally of the slideway,
- said plate members being spaced from and vertically below said door plate and paralleling the slideway,
- said plate members being disposed between said shelf portions of said longitudinal frame members and being in spaced apart coplanar relation transversely of the door plate, and being substantially equally spaced from the slideway longitudinal centerline,
- said plate members each being formed to define a row of uniformly spaced apart through apertures, which row extends longitudinally of the respective said plate members,
- first and second gears keyed to said shaft in coaxial relation thereto,
- with said first gear being below one of said plate members and defining gear teeth in meshing relation with said row of apertures of said one plate member,
- and with said second gear being below the other of said plate members and defining gear teeth in meshing relation with said row of apertures of said other plate member,
- said meshing relation of said gear and rack sets comprising coupling means for effecting linear movement of the door plate between said positions, through said sets, on rotational movement of said shaft,
- and means for rotating said shaft in either direction to move the door plate between said position,
- said teeth of each of said gears being spaced from and below the door plate and protruding through, respectively, the respective said apertures of said plate members, respectively, in self cleaning relation thereto from the underside of same, when in said meshing relation, respectively, with the respective plate members, whereby said sets are self cleaning on rotation of said shaft, by the linear movement effecting action of said coupling means, and said sets in being on the underside of the door plate, the door plate thereby remains free of lifting bias induced by operation of said coupling means whereby the door plate rides level with the slideway,
- said plate members of said sets having end portions extending adjacent to said door plate one edge,
- with said plate members each including adjacent said end portions of same a bulk material dam for blocking bulk material discharge into said sets.