Abstract: A collapsible corner assembly is used in a collapsible form assembly to form a hollow structure, such as a four or five sided hollow concrete structure. One embodiment of the form assembly includes two collapsible corner assemblies, two fixed corner assemblies, and intermediate panels coupled to the corner assemblies. Each collapsible corner assembly preferably includes collapsible side portions and retractable members forming outer corner forming surfaces. To collapse the collapsible corner assembly, the retractable members are retracted and the collapsible side portions are moved inwardly. Collapsing the collapsible corner assemblies allows the form assembly to be removed from the hollow structure.

Abstract: A wedge apparatus for use with molds and a mold utilizing at least one wedge apparatus. The wedge apparatus includes a pair of attachment portions, each having an attachment surface and a wedge surface, a wedge portion, and a shaft. The wedge portion is slidably attached to the attachment portions and has a center portion terminating in a pair of center edges disposed at opposite angles to the wedge edges such that the center surface and the wedge surfaces form a substantially continuous mold surface. The shaft is attached to the center portion and extends through an opening through a cross member to maintain the center edges of the wedge portion in alignment with the wedge edges of the attachment portions.