System and method for raising and lowering sidewalls of a collapsible storage container

Abstract

The present invention discloses a novel apparatus and way to aid in the folding of a shipping container. One or more spring assemblies are provided to control the load applied during the folding process by applying a torque to a series of torsion springs and bar extending along at least a portion of the length of the container sidewall.

1 . A collapsible container comprising:
 a base panel;   a roof panel spaced a distance from the base panel and generally parallel to the base panel;   a pair of sidewalls extending between the base panel and the roof panel, the sidewalls rotatably coupled to the base panel along a bottom edge of the sidewalls;   a door panel and a front panel extending between the pair of sidewalls, the door panel and the front panel rotatably coupled to the roof panel;   a spring assembly positioned proximate the bottom edge of each sidewall and in contact with the sidewalls, the spring assembly comprising one or more bars extending approximately a length of the sidewall and a plurality of torsion springs coupled to the one or more bars;   wherein upon a folding of the sidewalls of the container, the sidewalls rotate to be generally parallel to the base panel, thereby causing the plurality of torsion springs to rotate and store energy produced by the sidewall rotation in the springs.   
     
     
         2 . The collapsible container of  claim 1  further comprising a locking mechanism for securing the sidewalls of the container in a folded condition. 
     
     
         3 . The collapsible container of  claim 2 , wherein the energy stored through twisting in the plurality of torsion springs is utilized to assist in raising the sidewalls of the container from a folded condition. 
     
     
         4 . The collapsible container of  claim 1 , wherein the spring assembly comprises a plurality of torsion springs arranged in one or more rows, where the torsion springs have a first end oriented parallel to the bar and captured by a washer secured to the bar and a second end generally perpendicular to the bar. 
     
     
         5 . The collapsible container of  claim 4 , wherein the one or more rows of springs comprises two rows, with a first row extending approximately a length of the sidewall and the plurality of springs positioned coaxial with the bar. 
     
     
         6 . The collapsible container of  claim 5 , wherein a second row of springs extends along a portion of the length of the sidewall. 
     
     
         7 . The collapsible container of  claim 6  further comprising a gear mechanism for coupling the second row of springs to the first row of springs. 
     
     
         8 . The collapsible container of  claim 1 , wherein the plurality of torsion springs of the spring assembly are equally spaced between hinges connecting the sidewalls to the base panel. 
     
     
         9 . The collapsible container of  claim 1 , wherein each of the torsion springs each have six to twelve active coils. 
     
     
         10 . The collapsible container of  claim 9 , wherein the torsion springs have a spring rate ranging from 6 lbf.-in./deg. to 11.75 lbf.-in./deg. 
     
     
         11 . The collapsible container of  claim 1  wherein the spring assembly further comprises an adjustment mechanism for adjusting a pre-torque to the plurality of torsion springs. 
     
     
         12 . A spring assembly for use in supporting folding of sidewalls of a collapsible container comprising:
 one or more bars extending approximately a length of a sidewall of the collapsible container, the one or more bars being parallel to an axis of rotation about which the sidewall rotates;   a plurality of torsion springs arranged about the bar and having a first end generally parallel to the bar and a second end generally perpendicular to the bar, the first end of each torsion spring coupled to the bar, and the second end in contact with a portion of the sidewall;   wherein upon folding of the sidewalls of the collapsible container, the sidewalls rotate to be generally parallel to a base panel, thereby causing the plurality of torsion springs to twist and store energy produced by a twisting of the springs.   
     
     
         13 . The spring assembly of  claim 12 , wherein the spring assembly is coaxial to the axis of rotation. 
     
     
         14 . The spring assembly of  claim 12 , wherein the energy stored through twisting in the plurality of torsion springs is utilized to assist in raising the sidewalls of the container from a folded condition 
     
     
         15 . The spring assembly of  claim 12 , wherein the plurality of torsion springs are positioned in one or more rows of springs with a first row extending approximately a length of the sidewall and the plurality of springs positioned coaxial with the bar. 
     
     
         16 . The spring assembly of  claim 15 , wherein a second row of springs extends along a second bar parallel to the bar, the second bar extending along a portion of the length of the sidewall. 
     
     
         17 . The spring assembly of  claim 16  further comprising a gear mechanism for coupling the second row of springs to the first row of springs. 
     
     
         18 . The spring assembly of  claim 12 , wherein the plurality of torsion springs are equally spaced between hinges connecting the sidewalls to a base panel of the container. 
     
     
         19 . The spring assembly of  claim 12 , wherein each of the torsion springs each have six to twelve active coils. 
     
     
         20 . The spring assembly of  claim 19 , wherein the torsion springs have a spring rate ranging from 6 lbf.-in./deg. to 11.75 lbf.-in./deg. 
     
     
         21 . The spring assembly of  claim 12  further comprising an adjustment mechanism for adjusting a pre-torque to the plurality of torsion springs. 
     
     
         22 . A system for controlling the folding of a sidewall for a collapsible storage container comprising:
 A primary spring assembly comprising:
 a first bar extending approximately a length of a sidewall of the collapsible container, the first bar being parallel to an axis of rotation about which the sidewall rotates; 
 a first plurality of torsion springs arranged about the first bar and having a first end generally parallel to the first bar and a second end generally perpendicular to the first bar, the first end of each torsion spring coupled to the first bar, and the second end in contact with a portion of the sidewall; 
   A secondary spring assembly positioned parallel to the primary spring assembly, the secondary spring assembly comprising:
 a second bar extending along at least a portion of the sidewall of the collapsible container, the second bar being parallel to an axis of rotation about which the sidewall rotates; 
 a second plurality of torsion springs arranged about the second bar and having a first end generally parallel to the second bar and a second end generally perpendicular to the second bar, the first end of each torsion spring coupled to the second bar by way of a washer, and the second end in contact with a portion of the sidewall; 
   A gear mechanism comprising first, second and third tooth gears configured in a generally vertical arrangement to couple movement of the second bar to movement of the first bar.   
     
     
         23 . The system of  claim 22 , wherein the primary spring assembly is located coaxial to the axis of rotation and the secondary spring assembly is located along an axis parallel to the axis of rotation. 
     
     
         24 . A method of storing energy for use in assembling a storage container comprising:
 rotating a sidewall of the storage container, the sidewall having a spring assembly comprising a bar extending along a length of the sidewall and a plurality of torsion springs arranged about the bar, where the torsion springs are coupled to the bar at a first end of the spring;   contacting a second end of the torsion springs with the sidewall; and,   twisting the torsion springs as the sidewall is lowered to a generally horizontal position.   
     
     
         25 . The method of  claim 24 , wherein the torsion springs have a spring rate ranging from 6 lbf.-in./deg. to 11.75 lbf.-in./deg.