Door

Abstract

The present invention relates to a door capable of preventing the door from being warped or bent and also from being damaged due to the penetration of moisture. The door of the present invention comprises front and rear panels which define front and rear surfaces of the door, respectively; a pair of horizontal frames which are fixed to upper and lower ends of the front and rear panels between the front and rear panels, respectively; and a pair of vertical frames which are fixed to right and left ends of the front and rear panels between the front and rear panels, respectively. Each of the vertical frames includes an inner frame which is fixed to an innermost position and made of wood, a middle frame which is fixed to an outer side of the inner frame and made of metal, and an outer frame which is fixed to an outer side of the middle frame and made of a synthetic resin. Further, a foaming agent is filled in an inner space formed between the front and rear panels by the frames to form a foam layer.

1 . A door, comprising: 
 front and rear panels defining, respectively, front and rear surfaces of the door;    a pair of horizontal frames fixed, respectively, to upper and lower ends of the front and rear panels between the front and rear panels; and    a pair of vertical frames fixed, respectively, to right and left ends of the front and rear panels between the front and rear panels,    wherein each of the vertical frames comprises an inner frame which is fixed to an innermost position and made of wood, a middle frame which is fixed to an outer side of the inner frame and made of metal, and an outer frame which is fixed to an outer side of the middle frame and made of a synthetic resin, and    wherein a foaming agent is filled in an inner space formed between the front and rear panels by the frames to form a foam layer.    
   
   
       2 . The door as claimed in  claim 1 , wherein the front and rear panels are made of either a synthetic resin or glass fiber.  
   
   
       3 . The door as claimed in  claim 1 , wherein the middle frame is made of aluminum.  
   
   
       4 . The door as claimed in  claim 1 , wherein the middle frame is formed to have an I-shaped section.  
   
   
       5 . The door as claimed in  claim 1 , wherein the middle frame is formed to have a C-shaped section.  
   
   
       6 . The door as claimed in  claim 1 , wherein the horizontal frame is made of a synthetic resin.  
   
   
       7 . The door as claimed in  claim 1 , wherein upper and lower ends of the vertical frames are installed between the pair of the horizontal frames.  
   
   
       8 . The door as claimed in  claim 1 , wherein the inner frame of the vertical frame is made of an LVL (Laminated Veneer Lumber) in which a plurality of sheets of plywood are laminated and attached one above another, and the plurality of sheets of plywood are attached in a right and left direction.  
   
   
       9 . The door as claimed in  claim 1 , wherein grooves are formed on front and rear ends of the middle frame, respectively, in a longitudinal direction thereof; and protrusions are formed on the front and rear panels, respectively, to be fitted into the grooves.