Reusable structure for forming joints in concrete

Claim 2

A reusable mold structure for forming a groove in a freshly poured concrete or similar settable composition mix in the formation of an expansion joint in the set concrete, said structure comprising: a metallic sheet folded upon itself to form an elongated, substantially U-shaped envelope adapted to be bodily lowered into a freshly poured concrete mix, said envelope in its undistorted condition including opposing sidewalls, having lower planar and parallel portions and upper, inwardly inclined, planar portions terminating in free contacting edges, and a bottom bight hingedly connecting the lower portions of the said sidewalls, said bight portion normally biasing the sidewalls toward each other, and a flexible wedge inserted between the upper sidewall portions, said wedge having a body formed with a tapered lower end for spreading the edges of the upper wall portions apart during the insertion of the wedge, said wedge having flat, substantially parallel sides engaged by the inner, facing surfaces of the said upper wall portions, and means for increasing the frictional engagement between the wedge and the inner, facing surfaces of the upper sidewall portions, the means for increasing the frictional engagement between the wedge and the upper sidewall portions is defined by roughened areas on the said inner surfaces of the said upper wall portions.

Claim 3

A reusable mold structure for forming a groove in a freshly poured concrete or similar settable composition mix in the formation of an expansion joint in the set concrete, said structure comprising: a metallic sheet folded upon itself to form an elongated, substantially U-shaped envelope adapted to be bodily lowered into a freshly poured concrete mix, said envelope in its undistorted condition including opposing sidewalls, having lower planar and parallel portions and upper, inwardly inclined, planar portions terminating in free contacting edges, and a bottom bight hingedly connecting the lower portions of the said sidewalls, said bight portion normally biasing the sidewalls toward each other, and a flexible wedge inserted between the upper sidewall portions, said wedge having a body formed with a tapered lower end for spreading the edges of the upper wall portions apart during the insertion of the wedge, said wedge having flat, substantially parallel sides engaged by the inner, facing surfaces of the said upper wall portions, and means for increasing the frictional engagement between the wedge and the inner, facing surfaces of the upper sidewall portions, said wedge having an enlarged head formed thereon and having upwardly and outwardly extending side wing portions laterally overlying the edges of the said upper wall portions, said wing portions having upwardly and outwardly inclined under surfaces adapted to rest in the concrete mix and form chamfered outer edges on the walls of the formed groove in the set concrete, said enlarged head having a bulged top portion running longitudinally along said wedge and defining an indicator means for indicating proper placement of the envelope and wedge in the concrete mix.

Claim 4

A reusable mold structure for forming a groove in a freshly poured concrete or similar settable composition mix in the formation of an expansion joint in the set concrete, said structure comprising: a metallic sheet folded upon itself to form an elongated, substantially U-shaped envelope adapted to be bodily lowered into a freshly poured concrete mix, said envelope in its undistorted condition including opposing sidewalls, having lower planar and parallel portions and upper, inwardly inclined, planar portions terminating in free contacting edges, and a bottom bight hingedly connecting the lower portions of the said sidewalls, said bight portion normally biasing the sidewalls toward each other, and a flexible wedge inserted between the upper sidewall portions, said wedge having a body formed with a tapered lower end for spreading the edges of the upper wall portions apart during the insertion of the wedge, said wedge having flat, substantially parallel sides engaged by the inner, facing surfaces of the said upper wall portions, and means for increasing the frictional engagement between the wedge and the inner, facing surfaces of the upper sidewall portions, said wedge having an enlarged head formed thereon and having upwardly and outwardly extending side wing portions laterally overlying the edges of the said upper wall portions, said wing portions having upwardly and outwardly inclined under surfaces adapted to rest in the concrete mix and form chamfered outer edges on the walls of the formed groove in the set concrete, said enlarged head having a bulged top portion running longitudinally along said wedge and defining an indicator means for indicating proper placement of the envelope and wedge in the concrete mix.

Claim 5

The structure of claim 2 wherein a longitudinal cavity lies beneath and contiguous to said bulged top portion, whereby the bulged portion is collapsible inwardly and downwardly.