Patent Publication Number: US-8534204-B2

Title: Hatch assembly for a railcar and method for assembling the same

Description:
BACKGROUND OF THE INVENTION 
     The embodiments described herein relate generally to a hatch assembly for railcars and, more particularly, to a hatch assembly for a railway hopper car that includes a mechanical timing device that is configured to unlock a hatch just prior to moving the hatch from a closed position to an open position. 
     Railroad cars generally have one or more compartments for storing and transporting materials. Each compartment includes a floor that defines an opening that facilitates removing materials from the compartments through the floor. At least some known railroad cars include a hatch assembly that selectively provides access to the materials through the opening in the floor. Known hatch assemblies include a frame that is coupled to the floor and a hatch that is coupled to the frame to selectively cover the opening. At least some known hatch assemblies include a rack and pinion assembly that is coupled to the hatch to selectively position the hatch between an open and closed position. During operation of known railway cars, the hatch assembly may be subjected to various forces and moments that impart vibrations to the hatch and to the rack and pinion assembly that may cause the hatch to shift position and open when the railroad car is traveling. These unexpected shifts in position may cause the hatch to open and allow the material in the railcar to undesirably spill through opening. 
     At least some, known hatch assemblies include a locking assembly for locking the hatch in a closed position, and a separate positioning system for moving the hatch between the open and closed positions. At least some known positioning systems are actuated with large torque actuators that impart a large force to the positioning system to open the hatch. These known positioning systems can be damaged when the positioning system is actuated with the locking assembly engaged in the locked position. Moreover, at least some known locking assemblies are manually locked and unlocked prior to moving the hatch between the open and closed position. These known locking assemblies are oftentimes damaged when an operator actuates the positioning system to open the hatch before moving the locking assembly to an unlocked position. A hatch system is needed that facilitates unlocking the hatch before moving the hatch to an open position. Specifically, a hatch assembly is needed with a mechanical timing device that is configured to automatically unlock the hatch just prior to moving the hatch from the closed position to the open position. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one aspect, a hatch assembly for use with a railway hopper car is provided. The railway hopper car includes sidewalls, end walls, and bottom walls for defining an interior volume. The bottom walls define a cargo well that has an opening for discharging materials transported by the hopper car. The hatch assembly includes a support frame that is coupled proximate to a bottom of the cargo well. A hatch is slideably coupled to the support frame. The hatch is moveable between a closed position and an open position for selectively covering the cargo well opening. A locking bar is coupled to the support frame for locking the hatch in the closed position. A hatch positioning system including a drive shaft that is coupled to the support frame, a locking assembly that is coupled to the drive shaft and is configured to selectively engage the locking bar, a positioning assembly that is coupled to the drive shaft, and a drive assembly that is coupled to the drive shaft. The hatch positioning system is configured to unlock the hatch when the drive shaft is rotated through a first angle of rotation to cause the locking assembly to disengage the locking bar, and to move the hatch to the open position when the drive shaft is further rotated after the first angle of rotation. 
     In another aspect, a hatch control apparatus for controlling an operation of a discharge hatch assembly that is coupled to a railway hopper car is provided. The hatch assembly includes a support frame that is coupled to a cargo well that defines an opening on the railway hopper car. A hatch is slideably coupled to the support frame and is moveable between a closed position and an open position for selectively covering the cargo well opening. A locking bar is coupled to the support frame for locking the hatch in the closed position. The hatch control apparatus includes a locking assembly that includes a locking member that is pivotably coupled to the hatch. The locking assembly is configured to unlock the hatch by selectively displacing the locking member from engagement with the locking bar. A positioning assembly is coupled to the hatch. The positioning assembly is configured to move the hatch between the closed position and an intermediate position that is between the open position and the closed position. A drive assembly is coupled to the hatch. The drive assembly is configured to selectively move the hatch between the intermediate position and the open position. A drive shaft is operatively coupled to the locking assembly, to the positioning assembly, and to the drive assembly. The hatch control apparatus is configured to unlock the hatch when the drive shaft is rotated through a first angle of rotation causing the locking assembly to disengage the locking bar, and to move the hatch from the closed position to the open position when the drive shaft is further rotated after the first angle of rotation. 
     In yet another aspect, a method of assembling a railway hopper car is provided. The method includes coupling first and second opposing sidewalls extending along a longitudinal axis to first and second opposing end walls extending substantially perpendicularly to the longitudinal axis to form an upper portion of the hopper car. A plurality of well panels are coupled to the upper portion of the hopper car for forming a lower portion of the hopper car. The lower portion includes one or more cargo wells. Each of the well panels slopes inwardly from the upper portion to an opening. A support frame is coupled to the cargo well. A hatch is coupled to the support frame. The hatch is moveable between a closed position and an open position along the longitudinal axis to selectively cover the cargo well opening. A locking assembly is coupled to the hatch to selectively lock the hatch in the closed position. A positioning assembly is coupled to the hatch for moving the hatch between the open position and an intermediate position that is between the open position and closed position. A drive assembly is coupled to the hatch for moving the hatch between the intermediate position and the open position. 
     In a further another aspect, a railway hopper car is provided. The railway hopper car includes an upper portion that includes a first sidewall, an opposing second sidewall, a first end wall, and an opposing second end wall. A lower portion is coupled to the upper portion to define an interior volume of the hopper car. The lower portion includes one or more cargo wells. Each cargo well includes a plurality of inwardly sloping well panels that extend between an inner edge an outer edge. The outer edge defines an opening that provides access to the interior volume. A support frame is coupled proximate to a bottom of the cargo well. A hatch is slideably coupled to the support frame. The hatch includes a leading edge and a trailing edge. The hatch is moveable between a closed position and an open position for selectively covering the cargo well opening. A locking bar is coupled to the support frame for locking the hatch in the closed position. A drive shaft is coupled to the support frame. A locking assembly is coupled to the drive shaft. The locking assembly includes a locking member that is pivotably coupled to the hatch to selectively engage the locking bar to lock the hatch, and a cam that is coupled to the drive shaft and is configured to contact the locking member during rotation of the drive shaft to unlock the hatch. A positioning assembly is coupled to the drive shaft to move the hatch from the closed position to an intermediate position that is between the closed position and the open position. The positioning assembly includes a positioning rack that is coupled to the hatch and a positioning pinion that is coupled to the drive shaft. The positioning pinion includes at least one tooth that extends outwardly from an outer surface of the positioning pinion. The at least one tooth is positioned on the drive shaft relative to the cam such that the cam unlocks the hatch before the tooth contacts the positioning rack. A drive assembly is coupled to the drive shaft for moving the hatch between the intermediate position and the open positioned. The drive shaft is rotated through a first angle of rotation to cause the locking assembly to disengage the locking bar. The drive shaft is rotated through a second angle of rotation after the first angle of rotation to cause the positioning assembly to move the hatch from the closed position to the open position, and is rotated through a third angle of rotation after the second angle of rotation to cause the drive assembly to move the hatch from the intermediate position to the open position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1-11  show exemplary embodiments of the apparatus described herein. 
         FIG. 1  is a side view of an exemplary railway hopper car having a cargo well assembly in accordance with the present invention. 
         FIG. 2  is a partial cross-sectional view of the railway hopper car shown in  FIG. 1  and taken along line  2 - 2 , with an exemplary embodiment of the cargo well assembly. 
         FIG. 3  is an enlarged front-side view of the cargo well assembly shown in  FIG. 1  and taken along area  3 , with an exemplary hatch assembly. 
         FIG. 4  is a cross-sectional view of the hatch assembly shown in  FIG. 3  and taken along line  4 - 4 , with hatch assembly shown in a closed position. 
         FIG. 5  is a cross-sectional view of the hatch assembly shown in  FIG. 3  and taken along line  5 - 5 , with hatch assembly shown in an open position. 
         FIG. 6  is partial bottom sectional view of the hatch assembly shown in  FIG. 3  and taken along line  6 - 6 . 
         FIG. 7  is a partial perspective view of the hatch assembly shown in  FIG. 3 , with hatch assembly shown in an intermediate position. 
         FIG. 8  is an enlarged side view of the hatch assembly shown in  FIG. 3  and taken along area  8 . 
         FIG. 9  is a partial cross-sectional view of the hatch assembly shown in  FIG. 8  and taken along line  9 - 9 , showing an exemplary positioning assembly of the exemplary hatch assembly. 
         FIG. 10  is a partial cross-sectional view of the hatch assembly shown in  FIG. 8  and taken along line  10 - 10 , showing an exemplary drive assembly of the exemplary hatch assembly. 
         FIG. 11  is a partial cross-sectional view of the hatch assembly shown in  FIG. 8  and taken along line  11 - 11 , showing an exemplary locking assembly of the exemplary hatch assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of a hatch assembly for use with a railway hopper car are described herein. The hatch assembly includes a mechanical timing device that enables an operator to rotate a shaft for unlocking a hatch just before moving the hatch from a closed position to an open position. More specifically, the hatch assembly includes a single drive shaft that is coupled to each of a locking assembly, a positioning assembly, and a driving assembly. The hatch assembly described herein includes a drive shaft that unlocks the hatch through a first rotation of the shaft, and opens the hatch through a second rotation of the shaft. This hatch assembly allows the operator to automatically unlock the hatch and move the hatch to the open position by manipulating a single drive shaft though a predefined angle of rotation, reducing time and cost associated with unloading material and reducing damage to the railcar. 
       FIG. 1  is a side view of an exemplary railway hopper car  10 .  FIG. 2  is a partial cross-sectional view of railway hopper car  10  taken along line  2 - 2  shown in  FIG. 1 . Identical components shown in  FIG. 2  are labeled with the same reference numbers used in  FIG. 1 . Railway hopper car  10  can be used to store and/or transport materials, such as dried distillers grains, dried distillers grains with solubles, and/or any other granular, semi-granular, or other flowable material. 
     In the exemplary embodiment, railway hopper car  10  includes an upper portion  14  that is coupled to a lower portion  16 . Lower portion  16  includes a front sill assembly  18 , a rear sill assembly  20 , and a cargo assembly  22  that extends between front sill assembly  18  and rear sill assembly  20 . Each sill assembly  18  and  20  includes a truck  24  that has a pair of axles  26  that are coupled to a pair of wheels  28 . Upper portion  14  includes a front end structure  30 , a rear end structure  32 , and two opposing sidewalls  34  extending therebetween. Front end structure  30  includes a front sloped sheet  36  that is coupled to a first end wall, i.e. a front end wall  38 . Front sloped sheet  36  extends obliquely inwardly from front end wall  38  towards rear end structure  32 . Rear end structure  32  includes a rear sloped sheet  40  that is coupled to a second end wall, i.e. a rear end wall  42 . Rear sloped sheet  40  extends obliquely inwardly from rear end wall  42  towards front end structure  30 . Front end structure  30  is coupled to front sill assembly  18  and to a forward portion  44  of cargo assembly  22 . Rear end structure  32  is coupled to rear sill assembly  20  and to a rear portion  46  of cargo assembly  22 . Sidewalls  34  are coupled between front end wall  38  and rear end wall  42 . A forward section  48  of sidewalls  34  is coupled to front end wall  38  and to front sloped sheet  36 . A rearward section  50  of sidewalls  34  is coupled to rear end wall  42  and to rear sloped sheet  40 . A bottom section  52  of sidewalls  34  is coupled to cargo assembly  22 . 
     A roof assembly  54  is coupled to a top section  56  of sidewalls  34  such that sidewalls  34  extend between roof assembly  54  and cargo assembly  22 . Roof assembly  54  is further coupled to a top  58  of front end wall  38  and a top  60  of rear end wall  42 . In an alternative embodiment, roof assembly  54 , sidewalls  34 , front end wall  38  and rear end wall  42  are formed integrally to form upper portion  14 . In the exemplary embodiment, at least one sill  62  is coupled to an outer surface  64  of cargo assembly  22  and an outer surface  66  of sidewalls  34 . Sill  62  extends between front end structure  30  and rear end structure  32 . At least one chord beam  67  extends between front end wall  38  and rear end wall  42  and is coupled to an outer surface  68  of roof assembly  54  and to sidewall outer surface  66 . Sidewalls  34 , roof assembly  54 , and cargo assembly  22  together define an interior volume  70  extending between front end wall  38  and rear end wall  42 . Interior volume  70  includes a length  72  extending along a longitudinal axis  74  defined between front end wall  38  and rear end wall  42 . 
     In the exemplary embodiment, cargo assembly  22  includes a plurality of cargo well assemblies  76  that are each coupled to an adjacent cargo well assembly  76  such that cargo assembly  22  extends along longitudinal axis  74  between front end structure  30  and rear end structure  32 . Each cargo well assembly  76  includes a cargo well  78  and a hatch assembly  80  that is coupled to cargo well  78 . Cargo well  78  includes two opposing side well panels  82 , a front well panel  84 , and a rear well panel  86 . Side well panels  82  are coupled between front well panel  84  and rear well panel  86  to form cargo well  78 . In the exemplary embodiment, side well panels  82 , front well panel  84 , and rear well panel  86  each extend between an inner edge  88  and an outer edge  90  of cargo well  78 . Side well panels  82 , front well panel  84 , and rear well panel  86  each include an inner surface  92  that extends downwardly and/or inwardly sloping from inner edge  88  to outer edge  90  to form cargo well  78  having a trapezoidal shape. In an alternative embodiment, cargo well  78  is formed having a conical shape. In the exemplary embodiment, front well panel  84  is coupled to an adjacent rear well panel  86  to form at least one longitudinal boundary  94  between adjacent cargo well assemblies  76  at the intersection of front well panel  84  and rear well panel  86 . Outer edge  90  of cargo well  78  defines an opening  96  that is sized to provide access to interior volume  70  through opening  96 . Hatch assembly  80  is slideably coupled to cargo well  78  and is sized to at least partially cover opening  96 . Hatch assembly  80  is configured to move with respect to cargo well  78  to selectively provide access to interior volume  70  through opening  96 . 
     In the exemplary embodiment, hatch assembly  80  includes a hatch  98 , a support frame  100 , and one or more hatch positioning systems  102 . Hatch  98  is slideably coupled to support frame  100  and is positionable along longitudinal axis  74 . Hatch  98  includes an inner surface  106  and an outer surface  108 , and is substantially rectangular extending between a first side  110  and an opposite second side  112 , and between a leading edge  114  and a trailing edge  116  along longitudinal axis  74 . Hatch  98  has a length  118  that is defined between first side  110  and second side  112  substantially perpendicularly to longitudinal axis  74 , and has a width  120  that is defined between leading edge  114  and trailing edge  116  along longitudinal axis  74 . 
     In the exemplary embodiment, support frame  100  is coupled to outer edge  90  of cargo well  78  to at least partially define opening  96 . Support frame  100  is configured to support hatch  98  from cargo well  78 . Support frame  100  includes two opposing support beams  122 , a first guiderail  124 , and a second guiderail  126 . Each support beam  122  is coupled to front well panel  84  and rear well panel  86 , respectively, and is coupled between first guiderail  124  and second guiderail  126 . First guiderail  124  is coupled to a side well panel  82  and extends between support beams  122  along longitudinal axis  74 . Second guiderail  126  is coupled to an opposite side well panel  82  and extends between support beams  122  along longitudinal axis  74 . First guiderail  124  and second guiderail  126  each extend between a first end  128  and a second end  130  and include a length  132  defined between first end  128  and second end  130  along longitudinal axis  74 . In the exemplary embodiment, length  132  is approximately equal to two times width  120  of hatch  98 . Alternatively, length  132  may be shorter than, or longer than, two times width  120 . In the exemplary embodiment, first guiderail  124  and second guiderail  126  extend outwardly from cargo well assembly  76  a distance  134  defined between front well panel  84  and first end  128 . Hatch  98  is slideably supported by first guiderail  124  and second guiderail  126  and is configured to move along length  132  to selectively provide access to interior volume  70  through opening  96 . 
       FIG. 3  is an enlarged front-side view of cargo well assembly  76  taken along area  3  shown in  FIG. 1 .  FIG. 4  is a cross-sectional view of hatch assembly  80  taken along line  4 - 4  shown in  FIG. 3 .  FIG. 5  is another cross-sectional view of hatch assembly  80  taken along line  5 - 5  shown in  FIG. 3 . Identical components shown in  FIG. 3  are labeled with the same reference numbers used in  FIG. 2 . Identical components shown in  FIG. 4  and  FIG. 5  are labeled with the same reference numbers used in  FIG. 3 . Referring to  FIG. 2  and  FIG. 3 , in the exemplary embodiment, hatch assembly  80  includes a first hatch positioning system  136 , a second hatch positioning system  138 , and a drive shaft  140  that is coupled between first hatch positioning system  136  and second hatch positioning system  138 . Each hatch positioning system  102  is substantially similar and is positioned adjacent outer edge  90  of cargo well  78 . Drive shaft  140  is rotatably coupled to support frame  100  and extends between a first end  142  and a second end  144  and defines a centerline axis  146  that extends between first end  142  and second end  144 . In the exemplary embodiment, first end  142  is coupled to first guiderail  124  and second end  144  is coupled to second guiderail  126  such that drive shaft  140  is oriented substantially perpendicular to longitudinal axis  74 . Drive shaft  140  is configured to rotate about an axis of rotation  148  that is coaxial with centerline axis  146 . Hatch positioning system  102  is coupled between hatch  98  and drive shaft  140  and is configured to move hatch  98  along longitudinal axis  74  upon a rotation of drive shaft  140 . First end  142  and second end  144  each include a capstan  150  that is configured to receive an actuator (not shown). First hatch positioning system  136  is positioned adjacent first end  142  of drive shaft  140  and side well panel  82 . Second hatch positioning system  138  is positioned adjacent second end  144  of drive shaft  140  and an opposite side well panel  82 . 
     Referring to  FIG. 4  and  FIG. 5 , in the exemplary embodiment, hatch  98  is slideably coupled to support frame  100  and is configured to selectively cover opening  96 , as desired. Hatch  98  is movable along longitudinal axis  74  between a first position (shown in  FIG. 4 ), i.e., a closed position  152  and a second position (shown in  FIG. 5 ), i.e., an open position  154 . In closed position  152 , hatch  98  covers opening  96  to prevent material contained in interior volume  70  of cargo well  78  from being channeled though opening  96 . In open position  154 , hatch  98  does not completely cover opening  96  such that material is channeled from interior volume  70  through opening  96 . Hatch positioning system  102  is configured to selectively move hatch  98  between closed position  152  and open position  154 . 
       FIG. 6  is partial bottom sectional view of hatch assembly  80  taken along line  6 - 6  shown in  FIG. 3 .  FIG. 7  is a partial perspective view of hatch assembly  80 .  FIG. 8  is an enlarged side view of hatch assembly  80  taken along area  8  shown in  FIG. 3 .  FIG. 9  is a partial cross-sectional view of hatch positioning system  102  taken along line  9 - 9  shown in  FIG. 8 .  FIG. 10  is a partial cross-sectional view of hatch positioning system  102  taken along line  10 - 10  shown in  FIG. 8 .  FIG. 11  is a partial cross-sectional view of hatch positioning system  102  taken along line  11 - 11  shown in  FIG. 8 . Identical components shown in  FIGS. 6-11  are labeled with the same reference numbers used in  FIG. 3 . In the exemplary embodiment, hatch positioning system  102  includes a locking assembly  156 , a positioning assembly  158 , and a drive assembly  160 . Locking assembly  156  is coupled to inner surface  106  of hatch  98  and is positioned adjacent first side  110  of hatch  98 . Locking assembly  156  is movable between a first position (shown in  FIG. 11 ), i.e., a locked position  162  and a second position (shown in phantom lines is  FIG. 11 ), i.e., an unlocked position  164 . In locked position  162 , locking assembly  156  locks hatch  98  and prevents hatch  98  from moving from closed position  152  to open position  154 . In unlocked position  164 , locking assembly  156  unlocks hatch  98  and enables hatch  98  to move between closed position  152  and open position  154 . In the exemplary embodiment, leading edge  114  of hatch  98  defines a rectangular opening  166  that extends from leading edge  114  towards trailing edge  116 . Opening  166  extends from inner surface  106  to outer surface  108  of hatch  98 . Locking assembly  156  is positioned adjacent opening  166  and is oriented with respect to hatch  98  such that at least a portion of locking assembly  156  extends through opening  166  and extends a distance  170  from outer surface  108  of hatch  98 . 
     Referring to  FIG. 7 ,  FIG. 8 , and  FIG. 11 , in the exemplary embodiment, locking assembly  156  includes a locking member  172  that is coupled to inner surface  106  of hatch  98 , a cam  174  that is coupled to drive shaft  140 , and a locking bar  176  that is coupled to support frame  100 . Locking member  172  includes a support assembly  178 , a pin  180 , and a locking arm  182 . Support assembly  178  is coupled to inner surface  106  and includes opposing support arms  184  that each extend outwardly from inner surface  106 . Support arms  184  define a cooperative opening  186  that extends through each support arm  184  and is oriented substantially parallel to centerline axis  146  of drive shaft  140 . Locking arm  182  is positioned between support arms  184  and is pivotably coupled to support arms  184  with pin  180 . Locking arm  182  extends between a root portion  188  and a tip portion  190 . Root portion  188  at least partially defines cooperative opening  186  and is coupled to support assembly  178  with pin  180  inserted through cooperative opening  186  of support assembly  178  and root portion  188 . Locking arm  182  extends obliquely from support assembly  178  and through hatch opening  166  such that tip portion  190  is positioned distance  170  from outer surface  108  of hatch  98 . A spring  192  is coupled to support assembly  178  and to locking arm  182  to bias locking arm  182  towards hatch  98 . Tip portion  190  includes a caming surface  194  that extends outwardly from an outer surface  196  of locking arm  182  towards drive shaft  140 . Cam  174  is coupled to drive shaft  140  such that a rotation of drive shaft  140  rotates cam  174  about axis  148 . Cam  174  extends outwardly from drive shaft  140  and is sized, shaped, and oriented to contact caming surface  194  during rotation of drive shaft  140 . 
     In the exemplary embodiment, locking bar  176  is coupled to support frame  100  and extends obliquely from support frame  100  towards outer surface  108  of hatch  98 . Locking bar  176  is positioned with respect to locking arm  182  such that locking bar  176  may contact locking arm  182 . In locked position  162 , locking arm  182  extends obliquely from support assembly  178  towards locking bar  176  and through opening  166 . Moreover, in locked position  162 , tip portion  190  is positioned with respect to locking bar  176  such that tip portion  190  may contact, or engage, locking bar  176  to lock hatch  98  and prevent hatch  98  from moving from closed position  152  to open position  154 . In unlocked position  164 , tip portion  190  is positioned a distance  197  from locking bar  176  such that tip portion  190  does not contact, or is disengaged from, locking bar  176  to unlock hatch  98  and enable hatch  98  to move from moving from closed position  152  to open position  154 . 
     During rotation of drive shaft  140 , cam  174  is rotated to contact caming surface  194  to pivot locking arm  182  about pin  180  and move tip portion  190  towards outer surface  108  of hatch  98 . Cam  174  moves tip portion  190  towards hatch  98  such that tip portion  190  does not contact locking bar  176  to enable hatch  98  to be moved from closed position  152  to open position  154 . 
     Referring to  FIG. 6 ,  FIG. 8 , and  FIG. 10 , in the exemplary embodiment, drive assembly  160  is positioned between locking assembly  156  and positioning assembly  158 . Drive assembly  160  includes a drive pinion  198  and a drive rack  200 . Drive pinion  198  is coupled to drive shaft  140  such that a rotation of drive shaft  140  rotates drive pinion  198  about axis of rotation  148 . Drive rack  200  is coupled to outer surface  108  of hatch  98  and is positioned with respect to drive pinion  198  such that drive pinion  198  engages drive rack  200  to move hatch  98  between closed position  152  and open position  154 . In the exemplary embodiment, drive pinion  198  includes a plurality of circumferentially-spaced teeth  202  that extend radially outwardly from an outer surface  204  of drive pinion  198 . Drive rack  200  includes a plurality of bars  206  that are axially-spaced along outer surface  108  to define a slot  208  between each bar  206  that is sized to receive teeth  202  therein. Drive rack  200  extends between a first end  210  and an opposite second end  212 , and is oriented with respect to longitudinal axis  74  to facilitate moving hatch  98  along longitudinal axis  74 . Drive rack  200  has a length  214  defined between first end  210  and second end  212  that enables drive assembly  160  to move hatch  98  between closed position  152  and open position  154 . First end  210  of drive rack  200  is position a first distance  216  from leading edge  114  of hatch  98  along longitudinal axis  74  such that drive pinion  198  does not contact drive rack  200  when hatch  98  is in closed position  152 . 
     Referring to  FIG. 6 ,  FIG. 7 , and  FIG. 9 , in the exemplary embodiment, positioning assembly  158  includes a positioning pinion  218  and a positioning rack  220 . Positioning pinion  218  is coupled to drive shaft  140  such that a rotation of drive shaft  140  rotates positioning pinion  218  about axis of rotation  148 . Positioning pinion  218  includes at least one tooth  222  that extends radially outwardly from an outer surface  224  of positioning pinion  218 . In the exemplary embodiment, tooth  222  is oriented on drive shaft  140  with respect to cam  174  such that cam  174  contacts caming surface  194  of locking arm  182  to unlock hatch  98  before tooth  222  engages positioning rack  220  as cam  174  and positioning pinion  218  are rotated by drive shaft  140 . In one embodiment, adjacent teeth  222  are spaced a circumferential distance  226  to define a gap  228  between adjacent teeth  222 . Gap  228  is sized to enable positioning pinion  218  to be rotated through a predefined angle of rotation without contacting positioning rack  220 , and to enable cam  174  to unlock hatch  98  before positioning pinion  218  engages positioning rack  220  to move hatch  98 . 
     In the exemplary embodiment, positioning rack  220  is coupled to outer surface  108  of hatch  98  and is positioned with respect to positioning pinion  218  such that positioning pinion  218  engages positioning rack  220  during a rotation of drive shaft  140 . Positioning rack  220  is oriented with respect to longitudinal axis  74  to facilitate moving hatch  98  along longitudinal axis  74 . Positioning rack  220  extends between a first end  230  and a second end  232  along longitudinal axis  74 . First end  230  of positioning rack  220  is positioned a second distance  234  from leading edge  114  of hatch  98  that is less than first distance  216  of drive rack  200  such that first end  230  of positioning rack  220  is closer to leading edge  114  of hatch  98  than first end  210  of drive rack  200 . 
     In the exemplary embodiment, positioning assembly  158  is configured to move hatch  98  from closed position  152  (shown in  FIG. 4 ) to a third position (shown in  FIG. 7 ), i.e. an intermediate position  236 , that is between closed position  152  and open position  154  (shown in  FIG. 5 ). In closed position  152 , positioning rack  220  is positioned with respect to positioning pinion  218  such that positioning pinion  218  contacts positioning rack  220  when drive shaft  140  is rotated through a predefined angle of rotation to move hatch  98  from closed position  152  to intermediate position  236 . In intermediate position  236 , drive rack  200  is positioned in contact with drive pinion  198  to enable drive assembly  160  to move hatch  98  from intermediate position  236  to open position  154  during rotation of drive shaft  140 . 
     In the exemplary embodiment, drive shaft  140  is configured to rotate positioning pinion  218 , drive pinion  198 , and cam  174  about axis  148  simultaneously. During operation of hatch positioning system  102 , with hatch  98  in closed position  152 , drive shaft  140  is rotated through a first angle of rotation to rotate cam  174  to contact locking arm  182  and move locking arm  182  from the locked position to the unlocked position. As drive shaft  140  rotates through the first angle of rotation, positioning pinion  218  is rotated to a position that is adjacent positioning rack  220 . After cam  174  has moved locking arm  182  to the unlocked position, drive shaft  140  is rotated through a second angle of rotation to rotate positioning pinion  218  to engage positioning rack  220  and move hatch  98  from closed position  152  to intermediate position  236 . As drive shaft  140  is rotated through the second angle of rotation, drive rack  200  is positioned adjacent drive pinion  198 . After hatch  98  has been moved to intermediate position  236 , drive shaft  140  is rotated through a third angle of rotation to rotate drive pinion  198  to engage drive rack  200  and to move hatch  98  from intermediate position  236  to open position  154 . 
     The above-described embodiments facilitate assembling a railway hopper car having a hatch assembly that includes a mechanical timing mechanism that includes a drive shaft that facilitates unlocking a hatch before moving the hatch from a closed position to an open position. The above-described hatch assembly is a cost effective and efficient means to assemble a railway hopper car that facilitates unlocking the hatch and moving the hatch to the open position by rotating a drive shaft though a predefined angle of rotation. The hatch assembly includes a drive shaft that is coupled to each of a locking assembly, a positioning assembly, and a driving assembly. The hatch assembly automatically unlocks the hatch through a first rotation of the shaft and opens the hatch through a second rotation of the shaft, which occurs after the first rotation. As a result, the hatch assembly facilitates reducing time and cost associated with unloading material and reducing damage to the railcar. 
     Exemplary embodiments of a hatch assembly for a railcar and method of assembling the same are described above in detail. The hatch assembly and method are not limited to the specific embodiments described herein, but rather, components of apparatus and/or steps of the method may be utilized independently and separately from other components and/or steps described herein. For example, the hatch assembly may also be used in combination with other railway containers and methods, and are not limited to practice with only the railway hopper car and methods as described herein. Further, the exemplary embodiment can be implemented and utilized in connection with many other hatch assembly applications. 
     Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.