Static structures (e.g. – buildings) – Facers; e.g. – modules – mutually bonded by internal settable... – Laterally related modules; e.g. – back-to-back
Reexamination Certificate
1996-11-07
2001-01-30
Chilcot, Richard (Department: 3635)
Static structures (e.g., buildings)
Facers; e.g., modules, mutually bonded by internal settable...
Laterally related modules; e.g., back-to-back
C052S357000, C052S358000, C052S363000, C052S379000, C052S424000, C052S570000
Reexamination Certificate
active
06178711
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally concerns self-supporting, molded construction forms used in the building industry.
The present invention particularly concerns building forms made from a large sheets of low-density plastic or polymeric material, often polyurethane or polystyrene, that are held in a spaced-parallel relationship by metal connecting members which are commonly made from steel. Cavities of the plastic and steel forms so assembled are filled with wet concrete. After the concrete is cured, the forms become a permanent part of the building's walls.
2. Description of the Prior Art
2.1 State of the Prior Art
Construction forms have been manufactured from polymeric material, often polyurethane or polystyrene, which expands within a mold to yield a rigid, low-density, foamed plastic forms. The forms typically have a tongue and groove arrangement on all sides to permit identical forms to be placed on either side, above, or below a one form. Extended vertical and/or horizontal cavities are created between adjacent forms. Diverse items from reinforcing steel rod (re-bar) to conduit may be passed lengthwise into these cavities, and even brought to the surfaces of the forms as desired. The cavities are filled with wet concrete, forming walls of contiguous concrete. The forms are left in place, instead of being removed, when the concrete cures. In this manner the forms are supported by, as well as supporting of, the concrete, and serve as insulation to the walls of the completed building structure.
One important problem with such forms has previously been solved. This problem is the necessity of providing mechanical support for finished material such as furring strips, paneling, wall board, etc. attached to a wall that is formed by use of the forms. One early concrete form solving this problem is shown in U.S. Pat. No. 4,223,501 for a CONCRETE FORM to DeLozier. The DeLozier concrete form has been sold commercially since approximately Sep. 23, 1980; the issuance date of the DeLozier patent. In the DeLozier concrete form, sidewalls of foam polymeric material are connected by transverse connecting members. The connecting members have and present at each of their ends a lip that is parallel to the surface of the wall, and that is suitable to engage a sheet metal screw.
In their preferred form, each connecting member of the DeLozier concrete form is preferably made from a single piece of sheet material, preferably from cold rolled steel. A central connecting web portion extends between, and is embedded within, sidewall members of the form. First and second imperforate flat attachment flange portions extend perpendicularly from the web portion, and parallel to the sidewalls. These flanges are embedded within the outer surfaces of the sidewall members. In this location they may receive and support fasteners, typically screws, that penetrate the polymeric material of the sidewall members.
A purported improvement to the DeLozier concrete form is taught in U.S. Pat. No. 4,879,855 for an ATTACHMENT AND REINFORCEMENT MEMBER FOR MOLDED CONSTRUCTION FORMS to Berrenberg. In the Berrenberg form the attachment and reinforcement member of a DeLozier-type concrete form has as its central portion expanded web steel. The end portions of this member are bent and fitted with covering strips of solid galvanized steel. The web and galvanized steel are embedded within a construction form during the manufacture of the form. The strips of the solid galvanized steel extend to, and appear, on the outer surfaces of the form. They therein provide attachment services to which any standard type of wall covering such as sheet rock, siding, paneling, lath for stucco, or brick veneer may be attached. These attachment strips are spaced at regular predetermined intervals. They also define the locations of (i) any vertical cavities and/or concrete posts embedded within the wall that is formed by the construction form, and/or (ii) any conduit or other channel material previously placed within the void of the form before the pouring of the concrete wall.
Important to the DeLozier and Berrenberg forms, and to all forms of this nature, the interior of the forms must have and present an array of relatively large openings to permit the ready flow of liquid concrete vertically through several arrayed forms, therein so as to ultimately provide a continuous concrete wall (in which the wall the connecting members are embedded, and to which wall the polymeric material forms the exterior sidewalls). Although the exterior surfaces of the forms are flat, as best suits their function as wall surfaces, the interior surfaces of the DeLozier, Berrenberg and other, like, forms are very complex. The forms produce a concrete wall that, if the polymeric material were to be somehow removed, would have the substantial appearance and surface texture of a waffle. The wall, and a waffle, are in the substantial structure of a grid surface with regular high and low (thick and thin) regions, and with somewhat smoothed undulations between regions. If the polymeric material were to chiseled or scraped off a completed wall, then an undulating concrete surface in an imperforate web pattern would be exposed.
Although the exact nature of the pattern of this concrete surface is not particularly important, it is obviously beneficial that the concrete of the wall should have both (i) no excessively thin or weak points, and (ii) no long straight lines long which the wall material is uniformly thin. In other words, it is not adverse that a common edible waffle should have fracture lines, or at least lines along which relatively thinner material of the waffle may be cut with a fork or knife. However, it is not desirable that a concrete wall should have such “fracture lines”. The surface of the concrete wall (as is hidden, and rendered flat, by the polymeric material) would better have the topology of the dimpled surface of a golf ball (rendered planar), or even the traditional smooth surface, than it would the surface of a waffle or cracker that is intended to fracture and to break along pre-existing fracture lines.
The interior voids of the DeLozier, Berrenberg and like forms, and the thickness of the concrete walls produced with these forms, basically vary in thickness over the scale of one connecting member to the next so that this interior void, and the interior surfaces of the form, will well support the full and free flow of concrete into every nook and cranny of the void. However, it is detrimental that the wall defined by the concrete form should vary in thickness over this scale. A wall that has relatively weaker, and relatively stronger, regions does not make the best and more efficient use of the concrete material, because the wall will always fracture at its weakest point, and along its weakest fracture line. One thing that should be avoided—if at all possible consistent with the necessity to flow concrete into the form—are long straight lines of relatively thinner thickness in the resulting concrete wall. These lines are obviously potential fracture sites, and crack lines, in the concrete wall.
Analysis of both the interior of the form and the resulting pattern of the wall that the form with regard to making both the best and strongest possible use of the available construction material (concrete) quickly leads back to the classic smooth-surface, flat, concrete wall. This classic wall—which is readily formed with traditional, normal, planar, concrete forms of wood of the like—has not been producible with the concrete forms of DeLozier and Berrenberg. The present invention will produce the classical smooth, flat concrete wall—only sheathed both sides with polymeric material. This will be the case nonetheless that (i) the polymeric material is strongly permanently attached to the interior concrete, and (ii) the poured concrete from which the wall is made has flowed reliably and well into all voids of the arrayed forms.
If an interior concrete wall made by forms of the present invention was
Laird Alex
Laird Andrew
Chilcot Richard
Fuess & Davidenas
Horton Yvonne M.
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