Rapid discharge railcar door

Abstract

A rapid discharge railcar door comprised of a main body composed of a polymer reinforced by an aluminum frame, the railcar door being designed to provide sufficient strength against load-bearing forces and withstand changes in temperature. The main body of the door is made from a polymer using a thermoplastic or thermoset molding process, such as injection molding, casting, resin transfer molding, reaction injection molding (RIM), and reinforced reaction injection molding (RRIM). The door reduces the overall weight of the railway car, thereby allowing more coal to be shipped per car.

We claim:  
     
         1 . A discharge door for selectively opening and closing a discharge opening in a railcar, the discharge door comprising: 
 an aluminum frame having hinge means at one end and an actuating beam at the other end; and,    a main body of polymer molded over the frame by a molding process to define a generally planar surface on the top side facing the interior of the car to close the opening and a ribbed surface on the bottom side to further reinforce the body.    
     
     
         2 . The discharge door of  claim 1 , wherein the hinge means includes spaced hinge members not covered by the polymer.  
     
     
         3 . The discharge door of  claim 1 , wherein the actuating beam is hollow.  
     
     
         4 . The discharge door of  claim 3 , wherein the hollow beam is box-shaped and extends from one side of the main body for interconnection with another door to operate as a set for a pair of side-by-side openings.  
     
     
         5 . The discharge door of  claim 1 , wherein a lip is formed peripherally to coact with the discharge opening to close same against leakage of coal.  
     
     
         6 . The discharge door of  claim 1 , which further includes a liner on the planar surface of an abrasion-resistant material.  
     
     
         7 . The discharge door of  claim 6 , wherein the liner is of a UV resistant ultrahigh molecular weight polyethylene.  
     
     
         8 . The discharge door of  claim 1 , wherein the main body of polymer is composed of a thermoset polymer.  
     
     
         9 . The discharge door of  claim 1 , wherein the main body of polymer is composed of a polycyclic olefin based polymer.  
     
     
         10 . The discharge door of  claim 1 , wherein the main body of polymer is composed of polydicyclopentadiene.  
     
     
         11 . The discharge door of  claim 1 , wherein the molding process is selected from resin casting, resin transfer molding, reaction injection molding, and reinforced reaction injection molding.  
     
     
         12 . The discharge door of  claim 1 , wherein the molding process is reaction injection molding.  
     
     
         13 . In a hopper coal car having a bottom with a plurality of discharge openings, a plurality of discharge doors for selectively opening and closing said openings, the improvement being in said doors, each door comprising: 
 an aluminum frame having hinge means at one end and an actuating beam at the other end, and,    a main body of polymer molded over the frame by a molding process to define a generally planar surface on the top side facing the interior of the car to close the opening and a ribbed surface on the bottom side to further reinforce the body.    
     
     
         14 . The combination of  claim 13 , wherein the discharge opening and doors extend transversely of the car.  
     
     
         15 . The combination of  claim 13 , wherein the discharge opening and doors extend longitudinally of the car.  
     
     
         16 . The combination of  claim 13 , wherein the beam includes an extension at one side of the main body, and connecting means interconnects a pair of doors in side-by side relation as a set for a pair of transversely spaced apart discharge openings.  
     
     
         17 . The combination of  claim 16 , wherein the connecting means includes a bracket attached to the beam extensions.  
     
     
         18 . The combination of  claim 13 , wherein the ends of the beams for each door are substantially flush with the sides of the main body, and wherein the connecting means interconnects a pair of doors in side-by-side relation as a set for a pair of transversely spaced apart discharge openings.  
     
     
         19 . The combination of  claim 18 , wherein the connecting means includes a spline received in and attached to said beams.  
     
     
         20 . The combination of  claim 13 , wherein the main body of polymer is composed of a thermoset polymer.  
     
     
         21 . The combination of  claim 13 , wherein the main body of polymer is composed of a polycyclic olefin based polymer.  
     
     
         22 . The combination of  claim 13 , wherein the main body of polymer is composed of polydicyclopentadiene.  
     
     
         23 . The combination of  claim 13 , wherein the molding process is selected from resin casting, resin transfer molding, reaction injection molding, and reinforced reaction injection molding.  
     
     
         24 . The combination of  claim 13 , wherein the molding process is reaction injection molding.  
     
     
         25 . A discharge door for selectively opening and closing a discharge comprising: 
 a metal frame; and,    a main body of polymer molded over the frame.    
     
     
         26 . The discharge door described in  claim 25 , wherein the frame has two ends and includes hinge means at one end and an actuating beam at the other end.  
     
     
         27 . The discharge door described in  claim 25 , wherein the metal is aluminum.  
     
     
         28 . The discharge door described in  claim 25 , wherein the molding process is selected from resin casting, resin transfer molding, reaction injection molding, and reinforced reaction injection molding.  
     
     
         29 . The discharge door described in  claim 25 , wherein the main body of polymer is composed of a polycyclic olefin based polymer.  
     
     
         30 . A process for improving the structural properties of an aluminum frame by placing an aluminum frame in a mold and over molding the frame with a polymeric material that shrinks around the frame placing the frame under compression.  
     
     
         31 . The process described in  claim 30  where the over molding process used is reaction injection molding.  
     
     
         32 . The process described in  claim 30  where the over molding polymeric material is a thermoset.  
     
     
         33 . The process described in  claim 30  where the over molding polymeric material is a polycyclic olefin based polymer.  
     
     
         34 . The process described in  claim 30  where the over molding polymeric material is polydicyclopentadiene.