Collapsible inside corner form

Abstract

A corner form assembly for forming inside corners of concrete structures, including first form subassembly for forming a first surface of the concrete structure and a second form subassembly for forming a second surface of the concrete structure oriented at an angle less than 180° relative to the first surface. A corner form assembly is pivotally attached to the second form assembly for movement between a set position for forming the concrete structure and a folded position. The corner form assembly is releasably secured to the first form assembly when in the set position and is provided with a relief angle to permit folding of the second form assembly relative to the concrete structure.

1 . An inside corner form apparatus for use in forming the inside corner of a concrete structure, comprising: 
 (a) a first form subassembly for forming a first surface of the concrete structure;    (b) a second form subassembly for forming a second surface of the concrete structure oriented at an angle less than 180° relative to the first surface;    (c) a corner form assembly pivotally attached to the second form assembly for movement between a set position for forming the concrete structure and a folded position;    (d) connectors releasably securing the corner form assembly to the first form assembly when in the set position; and    (e) a relief angle of the corner form assembly to permit folding of the second form assembly relative to the concrete structure.    
   
   
       2 . An inside corner form assembly as defined in  claim 1 , wherein the second surface is oriented at a 90° angle relative to the first surface.  
   
   
       3 . An inside corner form assembly as defined in  claim 1 , wherein the first form assembly comprises a pair of form sections interconnected for relative pivotal movement between a set position for forming the concrete structure and a folded position.