Round bender

Abstract

A round bender is disclosed. The round bender may include a plurality of bending roll units disposed along a process line between a pair of bender frames so as to bend a straight shaped beam to have a curvature. Each of the plurality of bending roll units may include upper and lower bending rolls rotating between the pair of bender frames and may be adapted to bend the shaped beam to have the curvature when the shaped beam passes between the upper and lower bending rolls. A lower bending roll of a rearmost bending roll unit disposed on a rearmost part of the process line may be configured to be rotatable with reference to an upper bending roll of the rearmost bending roll unit so as to change a curvature radius of some portion of the shaped beam.

What is claimed is: 
     
         1 . A round bender comprising a plurality of bending roll units disposed along a process line between a pair of bender frames so as to bend a straight shaped beam to have a curvature,
 wherein each of the plurality of bending roll units include upper and lower bending rolls rotating between the pair of bender frames and is adapted to bend the shaped beam to have the curvature when the shaped beam passes between the upper and lower bending rolls, and   wherein a lower bending roll of a rearmost bending roll unit disposed on a rearmost part of the process line is configured to be rotatable with reference to an upper bending roll of the rearmost bending roll unit so as to change a curvature radius of some portion of the shaped beam.   
     
     
         2 . The round bender of  claim 1 , further comprising a curvature changing means rotating the lower bending roll of the rearmost bending roll unit with reference to the upper bending roll of the rearmost bending roll unit,
 wherein the curvature changing means are disposed at the rearmost bending roll unit between the pair of bender frames such that a rotational shaft of the upper bending roll is rotatably supported at the pair of bender frames, and a rotational shaft of the lower bending roll is movably disposed in a penetration hole formed at the pair of bender frames.   
     
     
         3 . The round bender of  claim 2 , wherein the curvature changing means comprise:
 a cylinder disposed at a middle portion above the pair of bender frames, and hinged to the pair of bender frames through a hinge bracket; and   a rotating fork having an upper end hinged to a rod of the cylinder, and connected to the rotational shafts of the upper and lower bending rolls of the rearmost bending roll unit at an outer of the pair of bender frames so as to rotate the rotational shaft of the lower bending roll in the penetration hole with respect to the rotational shaft of the upper bending roll according to operation of the cylinder.   
     
     
         4 . The round bender of  claim 3 , wherein the rotating fork comprises:
 a connecting bar disposed above the pair of bender frames and having a hinge end protruded from a middle portion of an upper surface of the connecting bar and hinged to the rod of the cylinder; and   a pair of rotating bars disposed at the outer of the pair of bender frames corresponding to the rearmost bending roll unit, wherein an upper end of the rotating bar is connected to an end of the connecting bar, the rotational shaft of the upper bending roll is rotatably mounted at an upper portion of the rotating bar, and a slide hole is formed at a lower portion of the rotating bar such that the rotational shaft of the lower bending roll is rotatably mounted at a slider slidably mounted in the slide hole.   
     
     
         5 . The round bender of  claim 3 , wherein the rotational shaft of the upper bending roll is rotatably mounted at a sliding block slidably mounted in a slide recess formed at an upper portion of the bender frame. 
     
     
         6 . A round bender for bending a straight shaped beam to have a curvature, comprising:
 a pair of bender frames mounted apart from each other on both sides of a base;   a first bending roll unit including an upper bending roll and a lower bending roll, disposed at a front portion on a process line between the pair of bender frames, and guiding the shaped beam;   a second bending roll unit including an upper bending roll and a lower bending roll, disposed at the rear of the first bending roll unit between the pair of bender frames, and slidably supporting the shaped beam along a curvature direction;   third, fourth, and fifth bending roll units respectively including an upper bending roll and a lower bending roll, sequentially disposed at the rear of the second bending roll unit between the pair of bender frames along the curvature, and forming the shaped beam to have a predetermined curvature when the shaped beam passes therethrough; and   a curvature changing means disposed between the bender frame and the fifth bending roll unit and rotating the lower bending roll of the fifth bending roll unit with reference to the upper bending roll of the fifth bending roll unit so as to change a curvature radius of some portion of the shaped beam.   
     
     
         7 . The round bender of  claim 6 , wherein the curvature changing means is mounted at the fifth bending roll unit between the pair of bender frames such that a rotational shaft of the upper bending roll is rotatably supported at the pair of bender frames, and a rotational shaft of the lower bending roll is movably disposed in a penetration hole formed at the pair of bender frames. 
     
     
         8 . The round bender of  claim 7 , wherein the curvature changing means comprise:
 a cylinder disposed at a middle portion above the pair of bender frames, and hinged to the pair of bender frames through a hinge bracket; and   a rotating fork having an upper end hinged to a rod of the cylinder, and connected to the rotational shafts of the upper and lower bending rolls of the fifth bending roll unit at an outer of the pair of bender frames so as to rotate the rotational shaft of the lower bending roll in the penetration hole with respect to the rotational shaft of the upper bending roll according to operation of the cylinder.   
     
     
         9 . The round bender of  claim 8 , wherein the rotating fork comprises:
 a connecting bar disposed above the pair of bender frames and having a hinge end protruded from a middle portion of an upper surface of the connecting bar and hinged to the rod of the cylinder; and   a pair of rotating bars disposed at the outer of the pair of bender frames corresponding to the fifth bending roll unit, wherein an upper end of the rotating bar is connected to an end of the connecting bar, the rotational shaft of the upper bending roll is rotatably mounted at an upper portion of the rotating bar, and a slide hole is formed at a lower portion of the rotating bar such that the rotational shaft of the lower bending roll is rotatably mounted at a slider slidably mounted in the slide hole.   
     
     
         10 . The round bender of  claim 8 , wherein the rotational shaft of the upper bending roll of the fifth bending roll unit is rotatably mounted at a sliding block slidably mounted in a slide recess formed at an upper portion of the bender frame. 
     
     
         11 . A round bender comprising at least three bending roll units disposed along a process line between a pair of bender frames so as to bend a straight shaped beam and including upper and lower bending rolls,
 wherein a lower bending roll of a rearmost bending roll unit on a process line is configured to be rotatable with reference to an upper bending roll of the rearmost bending roll unit so as to change a curvature radius of some portion of the shaped beam.   
     
     
         12 . The round bender of  claim 11 , further comprising a curvature changing means rotating the lower bending roll of the rearmost bending roll unit with reference to the upper bending roll of the rearmost bending roll unit,
 wherein the curvature changing means are disposed at the rearmost bending roll unit between the pair of bender frames such that a rotational shaft of the upper bending roll is rotatably supported at the pair of bender frames, and a rotational shaft of the lower bending roll is movably disposed in a penetration hole formed at the pair of bender frames.   
     
     
         13 . The round bender of  claim 12 , wherein the curvature changing means comprise:
 a cylinder disposed at a middle portion above the pair of bender frames, and hinged to the pair of bender frames through a hinge bracket; and   a rotating fork having an upper end hinged to a rod of the cylinder, and connected to the rotational shafts of the upper and lower bending rolls of the rearmost bending roll unit at an outer of the pair of bender frames so as to rotate the rotational shaft of the lower bending roll in the penetration hole with respect to the rotational shaft of the upper bending roll according to operation of the cylinder.   
     
     
         14 . The round bender of  claim 13 , wherein the rotating fork comprises:
 a connecting bar disposed above the pair of bender frames and having a hinge end protruded from a middle portion of an upper surface of the connecting bar and hinged to the rod of the cylinder; and   a pair of rotating bars disposed at the outer of the pair of bender frames corresponding to the rearmost bending roll unit, wherein an upper end of the rotating bar is connected to an end of the connecting bar, the rotational shaft of the upper bending roll is rotatably mounted at an upper portion of the rotating bar, and a slide hole is formed at a lower portion of the rotating bar such that the rotational shaft of the lower bending roll is rotatably mounted at a slider slidably mounted in the slide hole.   
     
     
         15 . The round bender of  claim 13 , wherein the rotational shaft of the upper bending roll is rotatably mounted at a sliding block slidably mounted in a slide recess formed at an upper portion of the bender frame. 
     
     
         16 . The round bender of  claim 1 , further comprising power delivery means mounted at the lower bending rolls of the bending roll units and delivering power therebetween. 
     
     
         17 . The round bender of  claim 6 , further comprising power delivery means mounted at the lower bending rolls of the first to the fifth bending roll units and delivering power therebetween. 
     
     
         18 . The round bender of  claim 11 , further comprising power delivery means mounted at the lower bending rolls of the bending roll units and delivering power therebetween. 
     
     
         19 . The round bender of  claim 10 , wherein position detecting means for detecting a position of a slider block is disposed between the sliding block used at the fifth bending roll unit and the bender frame guiding the sliding block. 
     
     
         20 . The round bender of  claim 19 , wherein the position detecting means comprise:
 a marking needle mounted at the sliding block; and   a graduated ruler attached to the bender frame corresponding to the marking needle.