Abstract:
A manual discharge door operating system for a hopper railcar includes a door actuation shaft coupled to the railcar extending across the width of the railcar. The door actuation shaft has distal ends accessible from opposite sides of the railcar with each distal end adapted to be engaged with a handle for rotation of the actuation shaft by the operator. Rotation of the actuation shaft opens and closes the discharge door of the hopper railcar through linkage assemblies. Preferably, a door operating linkage assembly is provided with an over-center closed position to hold the door in the closed position.

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/137,021, filed Jun. 1, 1999, entitled “Manual Door Operating System”. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an apparatus for opening the rotating discharge doors of a railway hopper car, and in particular, to an apparatus for manually opening the rotating hopper car discharge doors from either side of the hopper car by a single operator. 
     2. Description of the Prior Art 
     A common type of railroad freight car in use today is the open top freight car of the type wherein the load may be discharged through hoppers on the underside of the body. Such cars are generally referred to as hopper cars and are used to haul coal, phosphate and other commodities. After hopper cars are positioned over an unloading pit, the discharge doors of the hoppers are opened, allowing the material within the hopper car to be emptied into the pit. There are several methods available for opening and closing the hopper doors. 
     U.S. Pat. No. 3,596,609, issued to Ortner et. al., describes a system for simultaneously opening rotating hopper doors using a longitudinally extending operating rod connected to actuating shafts extending transversely below the hopper car body. Each door operating lever rotates an actuating shaft which in turn actuates a linkage mechanism to open and close the doors. 
     U.S. Pat. No. 4,741,274, issued to Ferris et. al., also describes a system for operating hopper dump doors on a railway hopper car. The lever is comprised of a single plate body portion with pivotal connections. The pivotal connections are coplanar with the door operating struts in a substantially vertical plan passing through the vertical transverse centerline of the center sill of the car to eliminate unnecessary rotational movements of the mechanism. 
     Other prior art references that teach operating mechanisms for opening and closing hopper doors include U.S. Pat. No. 3,187,684 to Ortner; U.S. Pat. No. 3,611,947 to Nagy; U.S. Pat. No. 3,786,764 to Beer et al.; U.S. Pat. No. 3,815,514 to Heap; U.S. Pat. No. 3,818,842 to Heap; U.S. Pat. No. 3,949,681 to Miller; U.S. Pat. No. 4,222,334 to Peterson; U.S. Pat. No. 4,366,757 to Funk; U.S. Pat. No. 4,601,244 to Fischer; and U.S. Pat. No. 5,823,118 to Angstrom. There are several disadvantages to the hopper door operating mechanisms described in some of the above-cited patents. One problem is that some of the prior art mechanisms are designed such that each actuating mechanism is connected to doors from two separate hoppers. Thus, if the mechanism fails, it effects the operation of two hoppers. Another disadvantage of some of the above described hopper door mechanisms is that, since the mechanisms are designed to operate doors from two adjacent hoppers, the mechanisms must push the doors closed with compressive forces being delivered to the mechanisms. This design makes it necessary to periodically adjust the mechanism as the system wears. In addition, the compressive forces applied to the hopper doors in closing may cause buckling problems. A further disadvantage of some of the above-described hopper cars is that the operating mechanisms limit the distance of the door motion, thus limiting the open area of the car bottom. This arrangement slows the unloading process and causes additional costs and potential damage to the car such as due to increased periods in thaw sheds. 
     Another prior art reference is Applicant&#39;s earlier U.S. Pat. No. 5,249,531 (hereinafter referred to as “Applicant&#39;s earlier &#39;531 patent”) entitled “Railroad Hopper Car Door Actuating Mechanism”, which issued on Oct. 5, 1993. 
     I addressed these problems in developing the railroad hopper car door actuating mechanism described in my earlier &#39;531 patent (hereinafter referred to as “my earlier &#39;531 patent”) which is incorporated herein by reference in its entirety. The door operating mechanism described in my prior patent does not provide for manual operation. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a manual mechanism for actuating the discharge doors of a hopper car which maintain some of the advantages of my prior invention. It is also an object of the present invention to provide a door actuating mechanism which does not need periodic adjustment to allow for wear of the parts. It is a further object of this invention to provide a door operating system for a hopper car in which the closing and lockup of the hopper doors are in tension, as opposed to compression type mechanisms. It is a further object of the present invention to provide a system which provides a significant opening in the bottom of a hopper car in order to allow quick and safe discharge of its contents. It is a further object of the present invention to provide a door operating system in which each door assembly has a positive over-center locking mechanism. It is a further object of the present invention to provide a mechanism that can be retrofitted into existing hopper cars as well as incorporated into new construction. 
     These and other objects may be accomplished by the manual railroad hopper door actuating mechanism of my invention. The manual railroad hopper door actuating mechanism includes a manually rotatable door actuation shaft that is accessible from either side of the railcar. The door actuation shaft rotates a first pivot arm that is coupled to a second door actuating pivot arm through a first linkage arm. A second door actuating linkage arm extends between the pivot connecting the first linkage arm and the second pivot arm and the hopper door pan for actuating the door. Rotation of the actuating shaft in a first direction will open the hopper door and rotation in the opposite direction will shut the hopper door. The door operating mechanism maintains the over-center closed configuration described in my earlier &#39;531 patent. 
     These and other advantages of the present invention will be clarified in the brief description of the preferred embodiments together with the attached figures wherein like reference numerals represent like elements throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side view of the manual door actuating mechanism of my invention in its closed position; and 
     FIG. 2 is a schematic side view of the manual door actuating mechanism shown in FIG. 1 in the open position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The construction of a standard hopper railcar is well-known in the industry and is described in greater detail in my earlier &#39;531 patent, which is incorporated herein by reference. FIGS. 1 and 2 schematically illustrate the manual railroad hopper door actuating mechanism  10  of my invention. 
     The door actuating mechanism  10  includes a rotatable door actuation shaft  12  rotatably mounted to a center sill  14  of the railcar through mounting bracket  16 . The door actuation shaft  12  extends across the width of the railcar and is accessible by the operator on either side of the railcar. The door actuation shaft  12  may include a coupling, aperture or the like (not shown) at the distal ends thereof for receipt of an actuating handle/leverage bar for rotation of the actuation shaft  12  by the operator. Any conventional coupling for receipt of the handle will be sufficient. Further, the handle may simply be an elongated steel bar. Further, frame members along the sides of the railcar, such as side sills (not shown), may also additionally include mounting brackets for locating the actuation shaft  12 . The support for the actuation shaft  12  is not limited to a single bracket  16 . 
     A first pivot arm  18  is attached to the actuation shaft  12  for rotation therewith as will be described hereinafter. A distal end of the pivot arm  18  is pivotably attached to one end of a first linkage arm  20  by a pivot pin  22 . An opposite end of the linkage arm  20  is pivotably attached to a distal end of a second pivot arm  24  by a pivot pin  26 . An opposite end of the pivot arm  24  is mounted for rotation about the axis of a pin  28 . Pin  28  is mounted to the center sill  14  by a bracket  30 . One end of a second, door operating linkage arm  32  is pivotably attached to the arm  20  and the arm  24  by pin  26 . The second end of the linkage arm  32  is attached to a door spreader  34  through coupling pin  36 . The door spreader  34  extends across a door pan  38  and is attached thereto on opposite sides of the center sill  14 . The door pan  38  pivots about a hinge pin  40  to move between the open and closed positions. The linkage arm  32  includes a cutout  42  which rests against the pin  28  in the over-center closed position shown in FIG.  1 . 
     The spreader  34 , linkage arm  32  including cutout  42 , pivot arm  24  and pin  28  are similar to the elements in my prior door operating mechanism discussed in my earlier &#39;531 patent. The present invention is specifically intended to maintain the same advantages provided by these elements discussed in my earlier &#39;531 patent. This also makes retrofitting of the present invention particularly simple in those railcars incorporating the door operating design of my earlier &#39;531 patent. The present invention is also easily retrofitted to hopper railcars that do not include the design of my earlier &#39;531 patent. There is no special equipment needed to retrofit an existing railcar with the present design. Additionally, there are no special tools needed for operating the door operating mechanism of the present invention. 
     A lock (not shown) may be provided to prevent unwanted actuation of the door actuating mechanism  10 . The lock can take any desired form. For example, a gear or ratchet wheel may be secured to the shaft  12  with a locking pawl releasably engaged with the gear or ratchet wheel. The locking pawl could be pivotably mounted on the bracket  16  for pivoting into and out of locking engagement with the shaft  12 . Other types of positive locking arrangements are possible. 
     In operation, the operator disengages the lock and rotates the actuation shaft  12  in the counterclockwise direction from the position shown in FIG. 1 to open the door pan  38 . As discussed above, the operator can access the shaft  12  from either side of the railcar and will use an engaging handle, typically a steel bar or the like. Counterclockwise (referencing FIG. 1) rotation of the shaft  12  will rotate the first pivot arm  18  counterclockwise with the shaft  12  about the axis of the shaft  12  and move the attached linkage arm  20  to the left, pivoting the second pivot arm  24  counterclockwise about the axis of the pin  28 . This movement will shift the linkage  32  to pivot the door pan  38  about hinge pin  40  to open the hopper doors as shown in FIG.  2 . The open position is shown in FIG.  2 . Closing the door pan  38  is simply the opposite procedure through the clockwise rotation (as shown in FIG. 2) of the shaft  12 . The over-center locking of the door actuating mechanism  10  is such that by swinging the door pans  38 , when the door pans  38  are open and the commodity has been fully discharged, the door pans  38  will actually swing shut and lock. The cantilever action of the pivot arms  18  and  24  and first linkage arm  20  uses the weight of the door structure to pull itself closed. 
     The manual railroad hopper door actuating mechanism  10  of my invention is designed for safe, flexible, economical unloading of coal and other bulk materials from railroad cars. The manual railroad hopper door actuating mechanism  10  of my invention maintains some of the advantages of my earlier automatic design. 
     The over-center door mechanism provides simple operation and reduces the possibility of back injury to the operator. The system requires virtually no readjustment or maintenance. Additionally, when the railcar is operated in rotary discharge operation, the manual railroad hopper door actuating mechanism  10  of my invention will maintain the hopper doors closed during the rotary dumping. The manual railroad hopper door actuating mechanism  10  of my invention requires only one operator who can actuate the system from either side of the car. The system can be easily retrofitted into existing cars, even cars with worn or damaged doors or that have uneven door spacing. 
     While the invention has been shown and described with regard to a particular embodiment, it will be understood that my invention is not limited to this particular embodiment. Many changes and modifications may be made to the present invention without departing from the spirit and scope thereof. For example, the door operating mechanism can be designed to open a double set of door pans. This modification of the door operating linkage is shown in my earlier &#39;531 patent. Further modifications are within the scope of the present invention.