Abstract:
Improved, modified flat wall insulating concrete forms similar to a “waffle grid” type for generating posts, beams, and interconnecting webs of concrete. The novel forms incorporate interlocking structure for a plural vertically stacked forms. The forms are provided as angled corner or straight forms having an overall length of four feet. Tie brackets connecting interior and exterior synthetic expanded foam walls of the form have flanges which are embedded within and concealed by the walls. Tie brackets are spaced apart from one another at one foot intervals, and from ends of the interior and exterior walls of the form by distance intervals of six inches. Interior and exterior walls are configured to enclose a void space therebetween. When filled with concrete, the space forms posts, beams, and webs filling openings which would otherwise occur among the posts and beams. The posts and beams, and webs are square or rectangular in cross section, presenting a uniform exterior panel thickness.

Description:
This application is related to application Ser. No. 09/932,095 entitled CORNER FORM FOR A MODULAR INSULATING CONCRETE FORM SYSTEM and Ser. No. 09/932,096 entitled FORM BRACING TIE BRACKET FOR MODULAR INSULATING CONCRETE FORM SYSTEM AND FORM USING THE SAME, filed concurrently herewith on Aug. 20, 2000. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to modular insulating concrete forms of the type which receive poured concrete and are abandoned in place after pouring, thereby becoming an integral part of a static structure being built. The invention is particularly applicable to residential and light commercial construction. The novel forms are usable by homeowners, contractors, municipal, industrial, and institutional personnel in building and improving existing structures wherever insulated load bearing walls are to be built from poured concrete. 
   2. Description of the Prior Art 
   Left-in-place insulting concrete forms for building foundations and load bearing walls from poured concrete are known. In commercial practice, courses of forms are stacked until the final desired height of a wall is attained. Concrete is poured into the erected forms and allowed to cure. The resultant wall must provide both strength and also insulation protection against the elements. Insulating concrete forms have been proposed to answer these needs. In order to maximize both strength and insulation values within a given volume dedicated to a left-in-place form wall, the concrete elements must be carefully designed to utilize a minimum amount of concrete, so that the balance of the available volume may be filled with the insulating form. 
   One of the more common designs is the so-called “waffle grid” type. The waffle grid design takes its name from the visual impression of the internal surfaces of its constituent form walls. Intersecting posts and beams formed after pouring of concrete, which would otherwise leave openings, are complemented by webs which close these openings. The webs are considerably thinner than the posts and beams. The overall visual effect is similar to that of typical waffle irons. Waffle grid walls, as well as all insulating concrete form walls, must address several needs. 
   One is that it is necessary that each form be properly aligned with respect to adjacent forms to assure that finished wall surfaces are flat and flush. Also, opposing exterior panels of each form section must be held in place without distortion of overall configuration of the finished wall. 
   A second problem of prior art forms is that they are not designed such that locations of tie brackets coincide with the ends of standard building elements. Illustratively, sheets of plywood and gypsum wall board are typically provided with length of eight feet and height of four feet. If a form section has tie brackets and associated plates or flanges serving as a structural members which can receive driven and threaded fasteners, and these plates or flanges are located at each end of the form section, then abutment of two form sections results in abutting plates or flanges. This arrangement will likely interfere with even spacing apart of tie brackets at even distance intervals of a whole number of feet since the two abutting end brackets will be spaced on either side of the center line. Thus, if a fastener is driven at the point of abutment, there will be no solid structural member to receive the fastener. 
   This makes it difficult to properly locate fastener positions for attaching building elements to the form. Flange location can be calculated, but calculation entails additional effort when constructing forms. 
   Another problem is that the prior art has not provided insulating concrete form walls which are conducive to laying a wall in increments of one foot, as measured from the outside corner, as is frequent construction practice. Prior art forms typically require shortening by cutting to accommodate building walls laid out in increments of one foot. 
   A representative waffle grid design and a representative post and beam design are illustrated in a color brochure entitled “Insulating Concrete Forms: Comfort And Security In An Easy-To-Use Package” (undated), published by the Insulating Concrete Form Association, Glenview, Ill. 60025. 
   Another problem of existing waffle grid insulating concrete forms is that none known to the present inventor has means for interlocking with forms of courses above and below. The prior art fails to describe the instant invention as claimed. 
   SUMMARY OF THE INVENTION 
   The present invention provides insulating concrete forms which provide the best features of both the “flat wall” and the “waffle grid” type forms which satisfy two practical needs. One need is that of forms which can be erected in interlocked stacks which oppose sliding and disengagement of one form with both its vertical and horizontal neighbors. The other need is to provide forms which favor current U.S. building practices with regard to dimensions. It is frequently the case that buildings are designed in increments of one foot and even in increments of four feet. The novel forms satisfy both needs. 
   Interlocking is achieved by forming male interlocking members in the top surface of each form, and corresponding female interlocking members in the bottom surface of each form. The male and female interlocks are vertically aligned so that a stack of forms will enable each form to interlock with a form placed directly thereon and also with the form located directly below. 
   The forms are configured such that pouring concrete into the void formed between the inner and outer opposing walls of insulating material generates a modified flat wall configuration having a substantially flat surface with vertical posts and horizontal beams at regular intervals. 
   Preferably, the posts and beams are configured as parallelepipeds so that all constituent material thereof contributes to compressive strength in at least one direction of an orthogonal or Cartesian system. No concrete is thus ineffectually used. Overall building costs and weight are minimized, while still affording maximal strength. Also, volume within the form devoted to insulating material is maximized, thereby maximizing temperature insulating value of the form. 
   Forms may be either straight or angled, the latter being known as corner forms because angled forms are usually used to form the corner of intersecting walls. Both straight and corner forms are dimensioned with regard to modular building. That is, the length of a straight form is preferably four feet. A corner form has combined length of both legs of four feet. These dimensions favor building designs laid out in increments of one, two, and four feet. This characteristic minimizes the number of forms which must be cut in length to achieve a desired wall length, thereby saving labor and tending to promote straightness and integrity of the finished poured wall. 
   Similarly, tie brackets connecting inner and outer walls of each form section are located at one foot intervals, the first being one half foot from the end of the form. This location prevents tie brackets of adjacent abutting forms in one course from interfering with regular spacing of the tie brackets along the entire length of the wall. Rather, tie bracket spacing remains constant. As a consequence, location of concealed flanges or plates of each tie bracket, which is employed to receive and support driven fasteners for fixing plywood and dry wall sections to the wall, is predictable. Effort and expense of mounting either interior or exterior finishing materials on the finished concrete wall is minimized. 
   Interlocking members of the form are spaced apart and dimensioned so that clogging with concrete is not a problem. If notches, or female interlocking members, were too small, it would be difficult to dislodge concrete overflow and other materials therefrom. They are spaced apart so that an inordinate number of notches which would otherwise require cleaning is avoided. 
   Accordingly, it is one object of the invention to provide insulating concrete forms which readily interlock when vertically stacked. 
   It is another object of the invention that the novel forms facilitate construction of building designs laid out in increments of one, two, and four feet, as measured from the outside corner of the form system. 
   It is a further object of the invention to minimize labor required to erect the forms. 
   Still another object of the invention is to enable ready location of concealed tie bracket flanges or plates when driving fasteners into the wall built by the novel forms. 
   An additional object of the invention is to maximize strength of the wall for the amount of concrete consumed. 
   It is again an object of the invention to maximize insulation value of the wall. 
   It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
   These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
       FIG. 1  is a diagrammatic, isometric view of one embodiment of the invention. 
       FIG. 2  is a diagrammatic top plan view of a second embodiment of the invention, drawn to scale greater than that of FIG.  1 . 
       FIG. 3  is an isometric detail view of FIG.  2 . 
       FIG. 4  is an isometric detail view of a concrete core typical of those formed in  FIGS. 1 and 2 . 
       FIG. 5  is a top plan detail view of a prior art concrete core corresponding to that of FIG.  4 . 
       FIG. 6  is an enlarged perspective detail view of the upper left of FIG.  3 . 
       FIG. 7  is an exaggerated, diagrammatic, side elevational detail view of FIG.  3 . 
       FIG. 8  is an end elevational view of FIG.  7 . 
       FIG. 9  is a perspective detail view of an internal component of FIG.  3 . 
       FIG. 10  is a side view of a concrete form system according to the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention provides improved insulating concrete forms for receiving poured concrete to form an insulated structural wall of a building (not shown). A corner form  100  is depicted in  FIG. 1. A  preferred configuration is more particularly set forth in my co-pending patent application Ser. No. 09/932,096, filed on Aug. 20, 2001. A corresponding straight form  200  is shown in FIG.  2 . Buildings having conventional rectangular floor plan features may be constructed employing both forms  100 ,  200 . Referring to  FIGS. 1 and 2 , insulating concrete form  100  includes a first insulating panel  102  and a second insulating panel  104 . Panels  102 ,  104  are preferably formed from expanded polystyrene or other synthetic resin closed cell foam. Each panel  102  or  104  has an interior surface concealed from view in  FIG. 1 , wherein form  100  is shown filled with concrete (indicated by stippling) for clarity of the view. Each panel  102  or  104  has a flat exterior surface ( 106  or  108 , respectively). Concrete form  200  includes a first insulating panel  202  and a second insulating panel  204 , both formed from expanded polystyrene closed cell foam. Panels  202 ,  204  have respective flat exterior surfaces  206 ,  208 . Form  100  differs from form  200  in that whereas form  200  is a straight form, form  100  incorporates an angle  128  formed between leg  130  and leg  132 . 
   The interior surfaces of panels  102 ,  104  and of  202 ,  204  face one another and leave a void space between each pair of panels  102 ,  104  and  202 ,  204 . In both forms  100 ,  200 , the interior surfaces are dimensioned and configured collectively such that a plurality of spaced apart posts  110 ,  112 ,  114 ,  116  and  210 ,  212 ,  214 ,  216 ,  218 ,  220 ,  222 ,  224  and a plurality of spaced apart beams intersecting posts  110  . . .  116  and  210  . . .  224  are formed. Beams  226 ,  228 ,  230  of form  200  are shown in the sectional view of FIG.  3 . Corresponding beams of form  100  (not visible in  FIG. 1 ) exist and are similar to those of form  200 . 
   In addition to posts and beams, the void forms webs  118 ,  120 ,  122 ,  124 ,  126  (see  FIG. 1 ) and  232 ,  234 ,  236 ,  238 ,  240  (see  FIG. 2 ) which span and join corresponding adjacent posts and beams, thereby closing square and rectangular openings (not shown) which would otherwise be formed among the intersecting posts and beams. A series of substantially rectilinear male forming projections  24  (see  FIG. 2 ) on the interior walls of insulating panel  202  and  204 , of form  200 , protrude from the panels to thereby form the parallelepiped webs ( FIG. 4 ) which span and join corresponding adjacent posts and beams of the modified flat wall.  FIG. 4  depicts a section of a cured modified flat wall concrete core of a finished wall. The section of the concrete core is typical of that which would be formed in a section of both forms  100 ,  200 . The nature of posts P, beams B, and webs W is clearly seen in FIG.  4 . The void and hence the finished concrete core are dimensioned and configured that posts, beams, and webs of the core are parallelepipeds joined where the posts and beams and webs intersect one another. It will further be seen from  FIGS. 1 ,  2 , and  3  that the posts and beams have exterior surfaces disposed only parallel and perpendicular to the longitudinal axis of their associated insulating panels. 
   These characteristics maximize effectiveness of both concrete and of expanded foam. Configuration of posts, beams, and webs maximizes their strength, particularly in the width of each form, where width refers to the dimension between exterior surfaces (e.g.,  206 ,  208  in  FIG. 2 ) of opposing insulating panels. This is better understood by considering a representative prior art concrete core  10  shown in FIG.  5 . Ovoid cross section of posts P in the prior art core has the consequence that the dimension indicated by arrow  12  contributes less than that indicated by arrow  14  to strength of post P in a direction parallel to arrows  12 ,  14 . By contrast, posts and beams in the present invention offer maximal magnitude between opposing exterior surfaces along the entire extent of those opposing exterior surfaces. This is the equivalent in the present invention of all dimensions corresponding to arrows  12 ,  14  of  FIG. 4  being of the greater magnitude of arrow  14 . Concrete forming that part of post P of  FIG. 5  is of reduced effectiveness in contributing to compressive strength, and hence is partially wasted. In the present invention, all of the concrete of the core contributes maximally to compressive strength. Configuration of posts, beams, and webs results in consumption of approximately ninety-eight percent of the concrete employed to form the configuration of the prior art design of  FIG. 5 , where overall dimensions are similar, while equalling or surpassing compressive strength of the prior art design of FIG.  5 . It follows that the volume of the expanded foam of the insulating panels is also maximized in that no partially wasted concrete comparable to that at the location of arrow  12  of  FIG. 5  exists in the present invention to serve as a heat conductor which would reduce thermal insulation performance of the finished wall. 
   Walls of a building are usually constructed by arranging insulating concrete forms in vertically stacked succeeding courses. When this practice is adopted, it is necessary to assure that the forms not slide horizontally or otherwise be displaced from direct vertical alignment. To this end, forms  100 ,  200  include interlocking members disposed to oppose parallel movement of one form with respect to a second form disposed in stacked, interlocked relationship. Interlocking structure is shown in  FIG. 6 , which is explained with reference to form  200 , but which will be understood to also be representative of form  100 .  FIG. 6  shows that upper surface  250  of insulating panel  202  has five projections  251 ,  252 ,  254 ,  256  and  257  formed along interior surface  258  of panel  202 . Although projections  251 ,  252 ,  254 ,  256  and  257  could if desired project above surrounding portions of upper surface  250 , it is preferred to recess projections  251 ,  252 ,  254 ,  256  and  257  such that their uppermost surfaces be flush with that of a rail  260  formed along the entire length of panel  202 . This feature both protects projections  251 ,  252 ,  254 ,  256  and  257  from damage and also minimizes overall height of form  200  for storage, packaging, and transport. 
   Projections  251 ,  252 ,  254 ,  256  and  257  provide male interlocking members which mate with corresponding female interlocking members of a form placed above. This is depicted in  FIG. 7 , wherein two similar straight forms  200 A,  200 B are in stacked vertical relation. It will be seen that for each projection  252 A,  254 A,  256 A, form  200 A has a corresponding notch  260 A,  262 A,  264 A formed in lower surface  266 A (more clearly seen by examining corresponding lower surface  266 B of form  200 B) directly below in vertical alignment therewith. Notches  260 A,  262 A,  264 A are female interlocking members dimensioned and configured to receive a corresponding one male interlocking member in close cooperation therewith, thereby prohibiting lateral slippage of the forms  100  and  200 . The projection  251 ,  257  at each of the two ends of form  100  and  200  are one half the length of the intermediate projections, allowing the end projection of two abutting forms  100  or  200  to occupy the same notch of form  100  or  200  above. 
   Thus far, forms  100 ,  200  have been described only in terms of respective spaced apart insulating panels  102 ,  104  and  202 ,  204 . It is preferred to provide each of forms  100 ,  200  as a united assembly. A tie bracket  268  shown in  FIG. 9  spans and connects insulating panels  102 ,  104  and  202 ,  204 . Tie bracket  268  may assume many possible designs and configurations, and is shown in its depicted form only as a representation of any desired design or configuration. A preferred configuration is more particularly set forth in my co-pending patent application Ser. No. 09/932,095, filed on Aug. 20, 2001. Each form  200  is closed at its proximal and distal ends by an optional separate bulkhead  300  (see FIG.  2 ). Bulkheads  300  are plates which slidably interfit with grooves formed at the ends of form  200 . Bulkheads  300  are used to terminate an insulated poured wall to accommodate interruptions such as doorways, windows, beam pockets and the like. Bulkheads  300  are omitted where two adjacent forms abut so that the resulting concrete core will be continuous and unbroken. 
   Regardless of its actual configuration, tie bracket  268  includes a first plate or flange  270 , a spaced apart parallel plate or flange  272 , and spanning elements  274  which hold flanges  270 ,  272  in spaced apart, parallel relation. When form  200  is fabricated, one flange  270  or  272  of each tie bracket  268  is embedded within panel  202  and the other flange  272  or  270  is embedded within panel  204 . Preferably, as shown in  FIG. 3 , a plurality of tie brackets  268  are employed to connect panels  202 ,  204 . 
   Tie brackets are vertically longitudinally arranged within form  200 . Flanges  270 ,  272  of tie brackets  268  have a height (see arrow  276  in  FIG. 9 ) equal to that of each insulating panel  202  or  204 . Panel height is indicated by arrow  278  in FIG.  3 . 
   One of the important attributes of the present invention is that dimensions of forms  100 ,  200  facilitate construction of buildings incorporating internal or partial dimensions, such as room length and width of intervals of whole numbers of feet, and of building elements such as prefabricated sheets of plywood and plasterboard having overall dimensions of four and eight feet. To this end, the overall length of form  200 , indicated by arrow  280  in  FIG. 3 , is four feet. Form  100  also accommodates intervals of four feet. First and second insulating panels  102 ,  104  are formed so that the overall length of leg  130  (see  FIG. 1 ) and the overall length of leg  132  (see  FIG. 1 ) when combined have a sum total length of four feet. Preferably, length of longer leg  130  is eighteen inches, and length of shorter leg  132  is thirty inches. 
   Location of tie brackets  268  within forms  100  and  200  also favors building dimension intervals of whole numbers of feet and of modules of four and eight feet. As shown in  FIG. 3 , tie bracket  268 A, which is adjacent to the proximal end of insulating panels  202 ,  204  of form  200 , is arranged so that vertical center line  282  of one flange is spaced apart from the proximal end of panels  202 ,  204  by a distance interval which is greater than two inches and less than one foot. Preferably, this distance interval, indicated by arrow  284 , is half a foot, or six inches, thereby maintaining a distance interval of one foot between adjacent tie brackets. If form  200  were scaled up, then the interval indicated by arrow  284  would preferably remain at a measurement of one half foot and the interval indicated by  288  would preferably be a whole number multiple of measurements of one foot. 
   The distance from the vertical center line  282  of one tie bracket  268  to the vertical center line  286 , indicated by arrow  288 , is a whole number multiple of measurements of one foot, and in forms  100 ,  200  intended for most residential applications will be exactly one foot. 
   Referring now to  FIGS. 6 and 7 , each interlocking member  252  . . .  258  and corresponding female members are spaced apart from adjacent members by a distance of one foot from center to center of each adjacent said interlocking member, as indicated by arrow  290 . Overall length of each interlocking member, indicated by arrow  292 , is greater in length than one inch, and is preferably two inches. 
   It should be understood that individual structural features described with reference to form  200  apply equally to form  100 . Forms  100 ,  200  may be modified or varied from the embodiments described above without departing from the inventive concept. For example, relative positions of female and male interlocking members may be reversed. 
   Referring now to  FIG. 10 , a side view an embodiment of the concrete form system of the invention is shown, with details of the interior of the system shown using hidden lines. Insulating panel  302 , which is typically four feet long, has a series of projections ( 306 ,  308 ,  310 ,  312 ,  314 ) located at its upper surface ( 301 ), a series of notches ( 326 ,  328 ,  330 ,  332 ,  334 ) located at its lower surface ( 303 ), and a series of tie bracket end flanges ( 304 ) positioned intermittently along the length of and extending the full height of insulating panel  302 . It can be seen that the tie brackets are positioned with an imaginary vertical center line of each tie bracket end flange  304  located at one foot intervals from one another, with the first and last tie brackets of the system positioned six inches from the respective side surfaces ( 305 ,  307 ) of the insulating panel  302 . As previously discussed, this positioning of the tie brackets allows consistent and regular spacing of the tie brackets at one foot intervals along the finished wall, with no inconsistency in tie bracket spacing when passing from one form to an adjacent form in the finished wall. This consistency allows someone using the concrete form system to know with confidence the location of each tie bracket flange in the finished wall, in spite of the fact that the flange is embedded in the concrete and cannot be seen. The location of the projections ( 306 ,  308 ,  310 ,  312 ,  314 ) and corresponding notches ( 326 ,  328 ,  330 ,  332 ,  334 ) are also spaced at intervals of one foot, with the projections ( 306 ,  314 ) and notches ( 326 ,  334 ) positioned adjacent side surfaces ( 305 ,  307 ) of insulating panel  302  being half the size of the projections ( 308 ,  310 ,  312 ) and notches ( 328 ,  330 ,  332 ) positioned intermediate the side surfaces of the insulating panel. By making the projections and notches located at the end of the panel half size, the “end” projections of two abutting forms are able to occupy the same full size notch or projection, respectively, of a form located above or below. By positioning the projections and notches at the midway point between the tie brackets, it is ensured that the interlocking projections and notches do not interfere with the tie brackets, and vice versa. 
   Although only straight and corner forms are depicted and described herein, it would be possible to employ the inventive concept in other configurations. For example, embodiments of the invention could include curved forms (not shown) and forms having more than one angle and two legs (not shown), or any combination of these characteristics. 
   It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.