Patent Abstract:
A railcar hatch cover latching system including a sliding mechanism attached to a movable portion of the hatch cover and a latching apparatus associated with the hatch cover. The latching apparatus has a biased assembly, a bar and at least one profiled stop. The bar extends through the biased assembly. The biased assembly is configured to allow the bar to pass through the biased assembly with a first force requirement. The at least one profiled stop is positioned on the bar to encounter the biased assembly and having a second force requirement to move the bar past the at least one profiled stop, the second force being greater than the first force.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hatch latching system, and, more particularly, to a hatch latching system for a slideable hatch. 
     2. Description of the Related Art 
     Bulk cargo carrying railroad cars often have openings along the top that are opened for the loading of materials and closed for transportation. Many bulk cargo railroad cars are utilized without any cover system. It is desirous to protect the materials carried in the interior of the railroad car from damage, which may be caused by weather or other environmental sources, such as particulate or biological material contained in the air. It is also desirous to prevent the bulk material from being dissipated by transportation due to the movement of air over the bulk material while it is in transit. 
     During the filling of the railcar, it is desirable to have the top of the railcar open so as to provide an easy way of loading the bulk material cargo from a delivering device, such as an overhead hopper. It is known to have railroad car hatches that are hinged and which are opened by releasing the latches on one side and pivoting the covers to the other side, thereby exposing a portion of the top of the railroad car so that the bulk cargo material may be loaded therein. It is also known to utilize latch systems that require the connection of the hatch to the framework or other structural elements surrounding the hatch. This is typically accomplished by having some portion extend from the framework to the hatch or from the hatch to the framework to engage in an interference type connection, thereby latching the hatch in place. 
     What is needed in the art is a hatch latching system that holds the hatch in position yet is easily released for opening or closing of the hatch. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a hatch latching system for a sliding hatch and, particularly, for a hatch system associated with a railcar system. 
     The invention consists, in one form thereof, of a railcar hatch cover latching system including a sliding mechanism and a latching apparatus. The sliding mechanism is attached to a moveable portion of the hatch cover. The latching apparatus is associated with the hatch cover. The latching apparatus includes a biased assembly, a bar, and at least one profiled stop. The bar extends through the biased assembly. The biased assembly is configured to allow the bar to pass through the biased assembly with a first force requirement. The at least one profiled stop is positioned on the bar to encounter the biased assembly and to thereby require a second force requirement to move the bar past the at least one profiled stop. The second force is greater than the first force. 
     An advantage of the present invention is that the latching system is primarily connected to the moveable hatch for easy assembly/disassembly. 
     Another advantage of the present invention is that movements of the slideable hatch in directions other than the latching direction do not substantially effect the latching force applied by the biasing assembly. 
     Another advantage of the present invention is that an automated opening and closing process of a passive nature can be utilized to overcome the latching force to thereby slide the hatch cover to either an open or a closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a railcar having an embodiment of the hatch latching system of the present invention with a closing device suspended thereover; 
         FIG. 2  is a partial cross section of the latching system of  FIG. 1  taken along lines  2 - 2  of  FIG. 1 ; 
         FIG. 3  is the latching system of  FIG. 2  with the hatch cover shown in an open position; 
         FIG. 4  is another partial cross section showing details of the latching system of  FIGS. 1-3 ; 
         FIG. 5  is another partial cross section of the latching system of  FIG. 4  with the latching system being opened past a profiled stop; 
         FIG. 6  is a partially exploded view of the biasing mechanism of the hatch latching system of  FIGS. 1-5  showing it in conjunction with a bracket that is connected to the lower portion of the hatch cover; and 
         FIG. 7  is a view of a distal end of the hatch cover latching system of  FIGS. 1-6 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates one embodiment of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a railcar system  10 , including a railcar  12 , moving by a closing system  14  in direction  16 . Cover  18  is being closed as railcar  12  moves in direction  16  by the interaction of elements of the railcar cover and closing system  14 . Cover  18  includes sliding hatch covers  20  with protrusions  22 , which may be in the form of rollers  22 , which encounter structural portions of closing system  14 , thereby moving covers  20  toward each other as railcar  12  moves in direction  16 . 
     Now, additionally referring to  FIGS. 2-7 , there is illustrated latching system  24  that is connected primarily to sliding hatch covers  20  with a bracket  28  connected to cover lower portion  26 . Bracket  28  receives a portion of latching system  24  therein, allowing vertical movement in a sliding manner of latching system  24  therein, but restraining lateral movement of the portion of the latching system contained therein. 
     Latching system  24  additionally includes a biased assembly  30 , a bar assembly  32 , and an alignment assembly  34 . Alignment assembly  34  includes a male portion  36  and a female portion  38  that interact with each other as covers  20  close. In the embodiment illustrated, there are two latching systems  24  for each rail cover  20 , one having a male portion  36  and the other having a female portion  38 . As can be seen in the figures this allows each railcar  20  to be identically configured and, since one is rotated at 180° relative to the other, the interaction of portions  36  and  38  allow for the engagement of covers  20  in a self-aligning manner as covers  20  are closed. The male portion  36  has a tapered feature allowing engagement with the female portion  38  to thereby assure alignment between covers  20 . 
     Bar assembly  32  additionally includes a bar  40  having profiled stops  42  connected thereto. Profiled stops  32  are illustrated as having a rounded, triangular profile. However, other profiles are other contemplated and, although symmetrically shown and is utilized as such in the main embodiment, non-symmetrical shapes, such as other triangular configurations and curvilinear shapes are also contemplated. The shape of profiled stops  42  interact with bias assembly  30  to cause the force required to move bar  40  through bias assembly  30  to vary depending upon the interaction of the biasing mechanism, the surface encountering profiled stops  42 , as well as the shape of profiled stops  42 . Profiled stops  42  are illustrated as being on the topside of bar  40 , although other configurations are also contemplated. Generally, profiled stops  42  will have to be oriented in order to properly interact with the biasing features of bias assembly  30 . 
     Biased assembly  30  includes a biased cassette  44  having a lower bearing surface  46 , an upper bearing surface  48 , springs  50 , and an adjustment mechanism  52 . Biased cassette  44  is slid into bracket  28 , which allows cassette  44  to move up and down in bracket  28  as various vibrations and movements of railcar  12  occurs without significantly altering the latching force provided by cassette  44 . Additionally, bar  40  is narrower than the opening in cassette  44 , allowing latitude for bar  40  to move side-to-side, again, without altering the latching force provided by the interaction between biased cassette  44  and the combination of bar  40  and profiled stops  42 . Bearings  46  and  48  may be rollers having bearings connected to portions of cassette  44 , or bearings  46  and  48  may themselves be a rolling sleeve, or bearing surfaces  46  and  48  may be fixed, having inherent sliding features of their own. 
     Springs  50  bias upper bearing  48  toward lower bearing  46  and may be stopped having a minimum distance therebetween. Bar  40  has a force required to slide it in a longitudinal direction through cassette  44  by way of the force from springs  50  as it is conveyed to bar  40 . As cover  20  is moved, profiled stop  42  encounters upper bearing  48 , which is part of the biasing features of bias cassette  44 , causing a greater force to be required to move bar  40  as profiled stop  42  interacts with the biased nature of bearings  46  and  48  so that a deliberate greater force is required to move cover  20  past stop  42 . 
     As can be seen in  FIG. 2 , cover  20  is in a closed position with alignment assembly  34  being shown engaged with the opposing reciprocal male and female portions  36  and  38 . In  FIG. 3 , cover  20  has been slid to an open position with alignment portions  36  and  38  being separated with the left set of portions  36  and  38  being shown separated from the complementary portions on the right. Additionally, biased cassette  44  has interacted with the other stop  42  to thereby hold cover  20  in an open position. As shown in  FIG. 1 , the operation of a mechanism overhead interacts with protrusions  22  to apply force that is translated into linear, or at least quasi-linear, force to open or close hatch covers  20 . Linear bearing arrangements  54  may be arranged along each cover  20  to provide stability in the movement of hatch covers  20 , allowing latching systems  24  to function as latching systems and not bearing systems. Although these features are separate, it is also contemplated that these features could be combined within the scope of the inventive nature of the present invention. It is also contemplated that although bars  40  are shown as being linear other shapes are also contemplated, such as curved and curvilinear. 
     As seen in  FIG. 4 , profiled stop  42  has encountered bearing  48  and the interaction between bearing  46  and  48  hold hatch cover  20  in a closed position relative to lower cover  26 . Adjusting mechanism  52  can be utilized to alter the biasing force of springs  50 , although it is also contemplated to produce a bias cassette  44  without an adjustment feature  52 . It is also contemplated that springs  50  may be non-linear in function, having different compression force requirements based upon the compressed length of spring  50 . As bar  40  is pushed to the right, as shown in  FIG. 5 , with increased force being needed to separate bearings  48  and  46  by the interaction of stop  42 , cover  20  is then being moved, if to the right, then to open cover  20 , or if being moved to the left, to thereby close cover  20 . 
     As can be seen in  FIG. 6 , biased cassette  44  is simply slid into bracket  28 . This allows the latching assembly connected to cover  20  to be easily removed without the removal of any fasteners or restraints. This also allows biased cassette  44  to move in a vertical manner to compensate for vibrations and movements as railcar  12  moves from place to place. Additionally, as already mentioned, bar  40  has a width that is substantially narrower than the width of cassette  44 , thereby allowing bar  40  to slide in the direction parallel with the longitudinal axis of railcar  12 . Bar  40  has a longitudinal axis and profiled stops  42  have a stop axis perpendicular therewith that can be understood to be in the direction in which bearing  48  must move as it overcomes stop  42 . This allows cassette  44  to move in bracket  28  in a direction parallel to the stop direction, yet the bracket prevents movement of the cassette in a longitudinal axis direction of bar  40 . Bar  40  can move in the direction substantially normal to the stop direction within biased cassette  44 . 
     Applicant&#39;s invention provides for sliding a bar through the biasing assembly  30  with a first force until encountering the profiled stop  42  connected to bar  40 . Continued sliding of bar  40  past stop  42  requires a second force, the second force being greater than the first force. Although it is understood that it is profiled step  42  that passes between biased cassette  44 &#39;s bearings  46  and  48  that the force is reduced once it reaches the top of profiled stop  42 . 
     Now, referring to  FIG. 7 , there is shown distal ends of bars  40  with aligning assembly  34  in an engaged position with portions  36  and  38  showing the alignment of covers  20  in a closed position. No latching between covers  20  occurs with the actual latching occurring within each cover and alignment assembly  34  is used for final alignment of covers  20  as they approach each other. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Technology Classification (CPC): 1