Composite plug door for use on railcars

Abstract

Composite doors are described which include a frame defining at least two openings and at least two composite panels situated within the openings in the frame. Preferred uses for such composite doors are as plug doors for use on railcars.

1 . A composite door comprising: 
 a frame defining at least two openings and    at least two composite panels situated within the openings in the frame.    
     
     
         2 . The composite door according to  claim 1 , wherein the frame comprises an outer frame and an inner frame.  
     
     
         3 . The composite door according to  claim 2 , wherein the outer frame is configured to define an outer periphery of the composite door.  
     
     
         4 . The composite door according to  claim 2 , wherein the inner frame is configured to fit within the outer frame.  
     
     
         5 . The composite door according to  claim 2 , wherein the outer frame is configured to define an outer periphery of the composite door and the inner frame is configured to fit within the outer frame.  
     
     
         6 . The composite door according to  claim 5 , wherein the inner frame defines the at least two openings and is further configured to receive and secure the at least two composite panels within the openings and said at least two composite panels are configured so as to fit within the openings.  
     
     
         7 . The composite door according to  claim 6 , wherein the composite panels fit within the inner frame in a tongue-in-groove configuration.  
     
     
         8 . The composite door according to  claim 5 , wherein the outer periphery and the outer frame are generally rectangular in shape.  
     
     
         9 . The composite door according to  claim 5 , wherein the outer frame comprises portions which are formed of raw metallic stock selected from the group consisting of angle iron, “C”-channel, “T”-flange, plate or combinations thereof.  
     
     
         10 . The composite door according to  claim 9 , wherein the outer frame portions are connected by at least one of welding and fasteners.  
     
     
         11 . The composite door according to  claim 1 , wherein the composite panels comprise an interior reinforcing core and outer skins of thermoformable material.  
     
     
         12 . The composite door according to  claim 11 , wherein the interior reinforcing core comprises aluminum, honeycomb, balsa wood, plywood or a combination thereof.  
     
     
         13 . The composite door according to  claim 11 , wherein the thermoformable material is a polyolefin.  
     
     
         14 . The composite door according to  claim 13 , wherein the polyolefin is a high density polyethylene.  
     
     
         15 . The composite door according to  claim 1 , wherein the frame defines a plurality of openings and there are a corresponding plurality of composite panels.  
     
     
         16 . The composite door according to  claim 1 , further comprising a material between the frame and the composite panels, wherein the material is selected from a sealant, a flexible structure, caulking or combinations thereof.  
     
     
         17 . The composite door according to  claim 1 , further comprising fasteners for holding the composite panels within the openings in the frame.  
     
     
         18 . The composite door according to  claim 1 , wherein the door is a plug door.  
     
     
         19 . The composite door according to  claim 18 , wherein the plug door is a railcar plug door.  
     
     
         20 . A railcar plug door comprising: 
 an outer frame configured to define an outer periphery of the plug door and an inner frame configured to fit within the outer frame, the inner frame defining at least two openings and    at least two composite panels situated within the openings in the inner frame.    
     
     
         21 . The railcar plug door according to  claim 20 , wherein there are a plurality of openings in the inner frame and a plurality of the composite panels.  
     
     
         22 . A method for forming a plug door, comprising 
 forming an outer frame defining an outer periphery of the plug door;    forming an inner frame configured to fit within the outer frame, wherein the inner frame defines at least two openings;    securing the inner frame within the outer frame; and    placing a composite panel within each of the at least two openings.    
     
     
         23 . The method according to  claim 22 , further comprising forming the composite panels by forming two outer skins of a thermoformable material, thermoforming the outer skins into a desired shape of the composite panels and sealing the outer skins around a core reinforcing material.