Box hand hole reinforcement and method of use

Abstract

A reinforcing member made of unitary construction is described. The reinforcing member has an outer face connected to an inner face by a middle frame. The inner face includes a first flange extending in a first direction from a first portion of the frame and a resiliently flexible second flange extending in an opposite direction from a flexible second portion of the frame. In use, an installer flexes the second flange and second frame portion so that the inner face will pass through the hand hole. Flexation may involve movement of the first flange toward the second flange, rotation of the second flange away from the outer face, or a combination of both. Once flexed, the inner face is inserted through the hand hole and the second flange is allowed to resume its unflexed position.

What is claimed is:  
     
         1 . A box hole reinforcement comprising: 
 a reinforcing member of unitary construction having an outer face connected to an inner face by a middle frame, the inner face having a first flange extending in a first direction from a first portion of the frame and a resiliently flexible second flange extending in an opposite direction from a flexible second portion of the frame.    
     
     
         2 . The reinforcement of  claim 1  wherein the flexible second flange comprises one or more guide elements tending to urge the second flange toward the first flange when subjected to a force perpendicular to a plane of the second flange.  
     
     
         3 . The reinforcement of  claim 2  wherein the guide elements comprise ribs extending perpendicular from the plane of the second flange.  
     
     
         4 . The reinforcement of  claim 1  wherein the flexible second flange comprises one or more guide elements tending to rotate the second flange away from the outer face when subjected to a force perpendicular to a plane of the second flange.  
     
     
         5 . The reinforcement of  claim 4  wherein the guide elements comprise angled ribs extending perpendicular from the plane of the second flange.  
     
     
         6 . The reinforcement of  claim 1  wherein the flexible second flange comprises slits perpendicular to a long axis of the flange.  
     
     
         7 . The reinforcement of  claim 6  wherein the slits extend into the flexible second portion of the frame.  
     
     
         8 . The reinforcement of  claim 1  wherein the reinforcing member is substantially trapezoidal.  
     
     
         9 . The reinforcement of  claim 1  wherein the first flange and first portion of the frame are substantially rigid.  
     
     
         10 . The reinforcement of  claim 9  wherein the first flange, first portion of the frame and outer face together have a U shaped cross section.  
     
     
         11 . A method of reinforcing a hand hole comprising: 
 providing a reinforcing member of unitary construction having an outer face connected to an inner face by a middle frame, the inner face having a first flange extending in a first direction from a first portion of the frame and a flexible second flange extending in an opposite direction from a flexible second portion of the frame;    flexing the second flange toward the first flange;    inserting the inner face through the hand hole; and    allowing the second flange to rotate back toward the outer face.    
     
     
         12 . The method of  claim 11  where the flexing step comprises the step of engaging guide member on the second flange with an edge of a wall that defines the hand hole.  
     
     
         13 . The method of  claim 11  wherein the flexing step comprises the step of rotating the second flange away from the outer face.  
     
     
         14 . The method of  claim 11  further comprising the step of inserting the first flange through the hole prior to the flexing step.