Inside concrete corewall form with particular three-way hinge assemblies therefor

#The present invention relates generally to concrete forms and has particular reference to a novel inside articulated collapsible form which is adapated for use in the formation of a concrete corewall shaft and, when in its extended position, presents panel facings which conform to the rectangular outline of the inside wall surfaces of the corewall to be formed by pouring wet concrete around the form, and when in its collapsed position, causes such panel facings to be withdrawn inwardly from such outline so that the form is loosened from the hardened corewall-forming concrete and may then be shifted vertically or axially along the corewall into a position for use in connection with a subsequent concrete pour, depending upon whether the corewall to be formed is to extend vertically or horizontally.

#Concrete corewalls of the character under consideration are commonly employed in the reaction of high-rise apartment and other buildings in the production of stairwells, elevator shafts, and the like. Corewalls are also cast in a horizontal position in connection with the creation of culverts, tunnels, or similar structures.

#Heretofore it has been the practice, when constructing an articulated collapsible concrete form for the inside surfaces of a rectangular corewall, to utilize a hinge joint at the mid-point of each of the two long sides of the rectangular form so that when the joints are broken inwardly the articulated form collapses to produce a smaller form structure which has the outline of two truncated triangles which are connected in tandem fashion with their truncated corners joined together. The over-all outline of such a collapsed form structure being smaller than the outline of the expanded form structure enables the collapsed structure to clear the walls of the hardened concrete of the corewall so that the collapsed form structure may be shifted longitudinally along the corewall to a new position for a subsequent concrete pour or for removal purposes.

#In the accompanying six sheets of drawings forming a part of this specification, two illustrative embodiments of the invention are shown.

#In these drawings:

#FIG. 1 is a plan view, somewhat schematic in its representation, looking downwards into a vertically disposed concrete corewall and showing the inside and outside form panels in position on the corewall preparatory to stripping of the two forms therefrom;

#Referring now to the drawings in detail and in particular to FIGS. 1 and 2, there is disclosed in these views a rectangular concrete corewall 10 which, for purposes of discussion herein, may be regarded as being a vertical elevator shaft or stairwell in a high-rise building which is under construction and is formed for the most part of concrete. The present invention is concerned with the construction of such a shaft-like corewall and this is accomplished in the usual manner by pouring wet concrete between a continuous rectangular outside form such as the illustrated form 12 and a continuous rectangular inside form 14.

#The outside concrete corewall form 12 as described herein is of conventional construction and is comprised of a series of quadrilaterally arranged form sides including left and right sides 16 and 18 (see FIG. 1), and front and rear form sides 20 and 22. Each of the various form sides is comprised of a gang or series of panel units 24, the number of units in each gang depending, of course, upon the dimensions of the corewall 10. In the illustrated outside concrete corewall form, the left and right form sides 16 and 18 embody two such panel units 24 each, while the front and rear form sides 20 and 22 embody three such panel units 24 each.

#The particular panel units 24 which are employed for the inside and outside concrete corewall forms 12 and 14 may vary widely, but for purposes of illustration herein, panel units of the "Versiform" type have been selected for exemplary illustration herein. A "Versiform" panel is a steel-clad panel consisting of a rectangular plywood facing which is bounded by a rectangular marginal steel frame. Such panels are manufactured and sold by Symons Corporation of Des Plaines, Ill. and for a full understanding of the nature of a "Versiform panel," reference may be had to a brochure which was published in 1974 by Symons Corporation and is entitled "Vertical Forming Systems." As shown throughout the drawings, each of the various panel units 24 regardless of whether they be associated with the inside concrete corewall form 14 or the outside form 12, includes a multi-ply plywood facing 26 and a marginal steel frame 28.