Abstract:
A modular pit fabricated from metallic components having a rail assembly crossing thereover, various beams and crossbeams provided across the top of the pit generally in alignment with the rail frame assembly, and a transfer screw conveyor, mounted upon structural supports, at an incline from beneath the rail assembly and its unloading area, to a position-exteriorly of the pit to provide for unloading and conveyance of granular material such as cement, coal, or any other type of flowable material.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    In the past, conventional rail pit construction was difficult, expensive and time consuming process. Rail pits were commonly built using concrete walls and floors that had to be located, formed, poured, allowed to set, and the forms removed. After the forms were removed, the excavated hole had to be backfilled and the backfill compacted. Next, the rail support substructure and material handling conveyers were built on top of the curved concrete walls and the rail tracks reinstalled. Because every pit installation has differing requirements and configurations, each pit had to be separately designed and appropriate plans drawn.  
           [0002]    The present invention solves the problems associated with the prior art by speeding and simplifying the process of building a rail pit. The present invention provides two preassembled units, a pit box assembly and a rail frame assembly, which can be quickly attached and installed in a number of configurations and do not require further assembly at a construction location. Further, the present invention eliminates the need for concrete forms, thereby eliminating the associated labor of constructing and removing concrete forms and the need to wait for the concrete walls to set before pit construction can continue.  
         SUMMARY OF THE INVENTION  
         [0003]    In its broadest aspect the present invention provides a bulk material unloading pit comprising a slab concrete base, a preassembled pit box assembly, a preassembled rail frame assembly, a gathering conveyor and a transfer conveyor. The preassembled pit box assembly comprises exterior walls and a top surface covering at least a portion of the pit box assembly to allow heavy equipment to drive over the top of the pit box assembly. The preassembled rail frame assembly comprises at least two beams and a deck plate defining at least two cutout sections over which boot lifts are mounted. The gathering conveyor is attached to the preassembled rail frame. The transfer conveyor is mounted within the pit box assembly. The pit box assembly, rail frame assembly, the gathering conveyor and the transfer conveyor are configured such that bulk material dropped through either of the two cutout sections is transferred to the gathering conveyor which subsequently transfers the bulk material to the transfer conveyor.  
           [0004]    A second broad aspect of the present invention provides a method of installing a modular bulk material unloading pit into an existing length of railroad track comprising the steps of removing a section of rail under which the modular pit will be located, excavating a hole in which the modular pit will be located, pouring a concrete slab upon which the modular pit will be located, placing a pit box assembly on the concrete slab, backfilling the hole around the pit box assembly, locating a rail frame assembly under the removed section of rail, attaching the rail frame assembly to the pit box assembly, and attaching rail to the rail frame assembly in place of the removed section of rail. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0005]    [0005]FIG. 1 is a top view of a modular pit according to an embodiment of the present invention;  
         [0006]    [0006]FIG. 2 is a sectional view of a modular pit according to an embodiment of the present invention;  
         [0007]    [0007]FIG. 3 is a sectional view of a rail frame assembly of a modular pit according to an embodiment of the present invention;  
         [0008]    [0008]FIG. 4 is a front sectional view of an installed modular pit according to an embodiment of the present invention;  
         [0009]    [0009]FIG. 5 is a right side sectional view of an installed modular pit according to an embodiment of the present invention having a rail car positioned over the modular pit;  
         [0010]    [0010]FIG. 6 is a sectional view of an installed rail frame assembly according to an embodiment of the present invention; and  
         [0011]    [0011]FIG. 7 is a sectional view of a I-beam of a rail frame assembly having a rail attached thereto by rail clips according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]    While the invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail the preferred embodiment of the invention. It is to be understood that the present disclosure is to be considered only as an example of the principles of the invention. This disclosure is not intended to limit the broad aspect of the invention to the illustrated embodiment.  
         [0013]    Referring to FIGS. 1 and 2, there is shown a modular pit  10  according to the present invention. The modular pit  10  generally comprises two main sections: a pit box assembly  12  and a rail frame assembly  14 . The pit box assembly  12  comprises four steel walls  16 ,  18 ,  20 ,  22 . Attached to walls  16  and  18  are two boot lift control consoles  24 ,  26  for boot lift height control circuitry. Also, attached to the pit box assembly  12  is a ladder  28  for gaining access to the interior of the pit box assembly  12 . Attached to the top of the walls  16  and  18  are steel crossbeams  29  and grating  30  (partially shown) of suitable stability heavy equipment and trucks driving over the pit box assembly  12 . The grating  30  is preferably steel grating and comprises several sections that may be individually removed and replaced in order to gain access to the interior of the pit box assembly  12 . The steel crossbeams  29  also provide additional stability to the pit box assembly  12 .  
         [0014]    Referring now to FIGS. 1 and 3, the rail frame assembly  14  comprises two I-beams  40 , each attached to a rail  42 . Connecting the two I-beams  40  is a gathering screw conveyor  44  and a deck plate  46 . Attached to a bottom of each I-beam  40  is a bottom cover assembly  48  and anchor traps  50 . The deck plate  46  defines two cutout sections  48  over which a boot lift will be mounted (as described below). An advantage of the present invention is that the rails  42  do not have to be removed in order to remove and replace the gathering screw conveyor  44  once the deck plate  46  has been removed.  
         [0015]    Referring to FIG. 2, a transfer screw conveyor  52  is mounted within the pit box assembly  12  and is attached to the gathering screw conveyor  44 . The transfer screw conveyor  52  is mounted through a transfer screw conveyor access opening  54  (FIG. 1) in the grating  30 .  
         [0016]    Referring to FIGS. 4, 5 and  6 , the modular pit  10  is installed by removing a section of rail (not shown) under which the modular pit  10  will be located. Next, hole  98  is excavated in which the modular pit  10  will be located. In the excavated hole, a concrete floor  100  is poured and sloped toward a sump pump tank  102 . Once the concrete floor  100  has set up, the pit box assembly  12  is placed on the floor  100  and shimmed until the pit box assembly  12  is level. Next the hole  98  is backfilled with concrete in 12 inch lifts  104  allowing each lift to set up to a degree before pouring the next lift  104 . When the lifts  104  reach the elevation of bottom of the rail frame assembly  14 , the pit box assembly  12  is field cut and the rail frame assembly  14  located and welded under the removed section of rail and within the field cut of the pit box assembly  12 . Next, the removed section of rail  42  is reattached to existing rail and welded to the I-beam  40  using rail clips  106 , as shown in FIG. 7. After the rail frame assembly  14  is installed, concrete lifts are poured to backfill the hole  98  to near elevation. Once the concrete has set, the hole  98  is backfilled to elevation with rock. Next, the transfer screw conveyor  52  is installed and attached to the gathering screw conveyor  44 . Boot lifts  108  (FIG. 5) are installed over the boot lift openings  48 , and boot lift control circuitry installed in the boot lift control consoles  24 ,  26 .  
         [0017]    Referring to FIG. 5, in operation a rail car  110  is positioned over the boot lift assemblies  108 . The boot lift assemblies  108  are raised to attach to rail car discharge chutes  112  and the chutes are  112  opened to allow material to fall into the boot lift assemblies. The gathering screw conveyor  44  is then operated to move the material to the transfer screw conveyor  52 . The transfer screw conveyor  52  is then operated to elevate the material to storage structures located outside the modular pit  10 .  
         [0018]    It will be appreciated by one of ordinary skill in the art that the present invention is not limited to any particular arrangement of the pit box assembly  12  in relation to the rail frame assembly, and that the rail frame assembly  14  may be placed in the pit box assembly  12  at any location or relative angle to accommodate various types and configurations of transfer conveyors  52  and railways. It will similarly be appreciated that the present invention is not limited to any particular type of conveyor system and could include a belt conveyors in place of either screw conveyor  44 ,  52  as the situation may require.  
         [0019]    While a specific embodiment has been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.