Groove-forming pattern assembly for a concrete wall form structure

Claim 1

In a concrete wall form structure, in combination, opposed wall form sides each of which presents an inside planar surface including at least one facing and against which wet concrete is adapted to be poured in the formation of a wall, and a composite two-piece grove-forming pattern assembly supported on one of said surfaces and being adapted to be removed bodily from the assembly formed groove when the wall form structure is stripped from the hardened concrete wall, said pattern assembly including an elongated ribbon-like base strip which is T-shape in transverse cross section and has its rear face connected to said one surface, and a separately-formed pattern strip coextensive with said base strip, said pattern strip being arched transversely so as to provide diverging side flanges and a connecting bight portion, and interlocking means on the side edges of said base strip and the distal edges of said side flanges of the pattern strip for removably securing said pattern strip in coextensive relationship on the base strip so as to define, in combination therewith, a tubular structure, said base strip including a longitudinally extending leg flange which projects centrally and transversely across The tubular structure and bears at its distal edge against the central region of said flat planar bight portion, and said bight portion is provided with integrally formed longitudinally extending channel-forming retaining flanges which straddle the distal edge region of said leg flange and confines the same therebetween.