Abstract:
A concrete form comprises cross members, plywood, and metal studs. The studs include a front wall, a rear wall, and a pair of side walls, the walls arranged to form a generally rectangular cross-section. A pair of inner walls extends between and perpendicular to the pair of side walls. A pair of flanges extends from the side walls. The flanges are aligned with each other and positioned between the front wall and the pair of inner walls. A portion of each stud is adapted for complementary engagement with the cross members. The cross members are attached to at least one of the inner walls and the flanges of the cut portion of the studs, and the plywood is mounted to the rear wall.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to concrete forms, and more specifically to studs used in the manufacture of concrete forms. 
   2. Description of the Prior Art 
   When concrete is poured, a form is usually built from plywood panels reinforced using 2″ by 4″ studs. Studs attach to the plywood, and cross members, known in the industry as walers, attach to the vertical studs for strength. The cross members are usually made out of wood. The cross members reinforce the form to keep it from buckling or bending under the force of the concrete when it is poured. Tie bars connect opposite sides of the form in order to hold them together against the force of the concrete. After the concrete is set, these forms are removed from the concrete, leaving a finished concrete wall. 
   The forms are prone to damage during transportation, installation, removal and storage. The primary cause of this damage relates to wear and deterioration of the wood forming the form structure. When forms are damaged, they must either be structurally reinforced or replaced. This, of course, leads to considerable cost and time requirements. Such costs outweigh any cost savings in using inexpensive wood studs. 
   Plywood panels are manufactured in standard sizes, and as such may be replaced with off-the-shelf components. However, the 2″×4″ wooden studs must be cut to size for each form. When the old studs deteriorate, replacement studs must be cut to fit the form, thus requiring that essentially the entire form be rebuilt. Rebuilding the forms requires considerable cost and time requirements. 
   An object of the present invention is to obviate or mitigate some of the disadvantages outlined above. 
   SUMMARY OF THE INVENTION 
   In accordance with one aspect of the present invention, there is provided a stud comprising:
         a) a front wall, a rear wall, and a pair of side walls, the walls arranged to form a generally rectangular cross-section;   b) a pair on inner walls extending between the pair of side walls; and
 
a pair of flanges extending from the side walls, the flanges being aligned with each other and positioned between the front wall and the pair of inner walls.
       

   In accordance with another aspect of the present invention, there is provided a concrete form including a plurality of cross members, a sheet of wood, and a plurality of studs. The studs have a front wall, a rear wall, and a pair of side walls, with the walls arranged to form a generally rectangular cross-section. A pair of inner walls extend between the pair of side walls. A pair of flanges extend from the side walls. The flanges are aligned with each other and are positioned between the front wall and the pair of inner walls. A portion of the studs is adapted for complementary engagement with the cross members. The cross members are attached to at least one of the inner walls and the flanges of the cut portion of the studs. The wood is mounted to the rear wall. 
   In one aspect, the present invention provides a concrete form comprising:
     a plurality of cross member;   a sheet of rigid material, such as a wood sheet; and   a plurality of studs having:   

   (a) a front wall, a rear wall, and a pair of side walls, the walls arranged to form a rectangular cross-section; 
   (b) a pair of inner walls extending between the pair of side walls; and 
   (c) a pair of opposed flanges, each one of the flanges extending substantially perpendicularly from a respective one of the side waits and extending towards the other of the side walls;
     wherein a portion of the studs is adapted for complementary engagement with the cross members, the cross members connecting at least two of the studs and being attached to at least one of the inner walls and the flanges of the cut portion of the studs, and the sheet of rigid material is mounted to the rear wall;   and wherein the cross members include end cross members and center cross members, the center cross members being attached to the inner walls and the end cross members being attached to the flanges.   

   In another aspect, the present invention provides a concrete form comprising a pair of opposing panels, each of the panels comprising: 
   (a) a plurality of studs arranged in a spaced apart parallel manner with respect to each other, each of the studs comprising a generally hollow elongate member having:
         (i) a front waIl, a rear wall, and first and second side walls, the side walls being spaced apart from each other and each extending between the front and rear walls to provide the stud with a generally rectangular cross-section;   (ii) at least one rib extending between and connecting the pair of side walls; and,   (iii) a pair of opposed flanges, each one of the flanges extending substantially perpendicularly from a respective one of the side waIls and extending towards the other of the side walls;       the studs being arranged in a planar manner with the respective front and rear waIls extending in the same direction;   

   (b) a plurality of cross members, extending perpendicularly between and connected to at least two of the studs and being arranged in a spaced apart parallel manner with respect to each other, the cross members being provided generally perpendicular to the studs and connected thereto, and wherein the cross members are provided adjacent the front walls of the studs and wherein the cross members include a narrow portion and a wide portion forming a generally “T” shaped structure; and, 
   (c) a sheet of rigid material, such as a wood sheet, overlying and connected to the rear walls of the plurality of studs;
     wherein the studs are adapted for complementary engagement with the cross members, the cross members being attached to at least one of the rib or the flanges of a cut portion of the studs;   and wherein the panels are arranged in a parallel and spaced apart relationship to each other with the sheets of rigid material facing each other.   

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the preferred embodiments of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein: 
       FIG. 1  is a schematic representation of a form. 
       FIG. 2  is a perspective view of a cross member in  FIG. 1 . 
       FIG. 3  is a top view the cross member of  FIG. 2 . 
       FIG. 4  is a back view of the cross member  FIG. 2 . 
       FIG. 5  is a perspective view of a stud of  FIG. 1 . 
       FIG. 6  is a cross section of  FIG. 5 . 
       FIG. 7  is a detailed view of a portion of  FIG. 1 . 
       FIG. 8  is a detailed view of another portion of  FIG. 1 . 
       FIG. 9  is a front view of another embodiment of a form. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a form used when pouring concrete is shown generally by the numeral  10 . The form generally comprises wood sheets  14  and  15  (such as plywood sheets), studs  16 , and cross members  18 . The wood sheets  14  and  15  are spaced apart and aligned with each other to form two sides of a generally rectangular space  12 . The wood sheets  14  and  15  are preferably 4′×8′ plywood sheets. The studs  16  are preferably 2″×4″ hollow metal studs, and are described more fully below with reference to  FIGS. 5 and 6 . The cross members  18  are described below with reference to  FIGS. 2 ,  3 , and  4 . 
   In an exemplary construction, the studs  16  span the length of the wood sheets and are spaced along the width of the wood sheets. The studs  16  are screwed to the wood sheets. Cross members  18  are placed so that they span the width of the wood sheets, are spaced along the length of the wood sheet, and intersect the studs  16 . The studs  16  and cross members  18  are screwed together to reinforce the wood sheets  14  and  15  respectively. The wood sheets  14  and  15  are thus reinforced by spacing the studs  16  along the width of the wood sheets, and spacing the cross members  18  along the length of the wood sheets. In the preferred embodiment, the cross members  18  span three studs  16 , with two of the studs  16  at opposite ends of the wood sheet, and the third stud  16  in the middle of the wood sheet. 
   The form  10  is used when pouring a concrete wall. The form  10  is placed into position, with the wood sheets  14  and  15  placed at the desired positions of the inner and outer surfaces of the concrete wall. Concrete is poured into the space  12  formed between the wood sheets  14  and  15 . The studs  16  and cross members  18  reinforce the wood sheets  14  and  15  against the hydrostatic pressure of the concrete. After the concrete has set, the form is removed, leaving the finished concrete wall. The inner and outer surfaces of the concrete wall are then located at the former positions of the wood sheets  14  and  15 . 
   Referring to  FIGS. 2 ,  3  and  4 , the cross member  18  is shown in more detail. The cross member  18  comprises two members  20 ,  30 , which are L-shaped in end view, and of substantially similar construction. As seen best in  FIG. 3 , the member  20  comprises a surface  22  and a flange  24  positioned at one side of surface  22 , extending outward from the surface  22 , and preferably perpendicular to the surface  22 . The flange  24  is inset from each end of the surface  22  to expose two flat portions  26 ,  28  at opposite ends of the surface  22 . The member  30  has corresponding wall  32 , flange  34 , and flat portions  36 ,  38 . The two members  20 ,  30  are placed in opposite orientations so that the sides of surfaces  22  and  32  with flanges  24  and  34  are facing each other. The flanges  24  and  34  are attached together by bolts  40 ,  44  and pin  42  disposed through holes  25   a ,  25   b , and  25   c  in flanges  24  and  34 , thereby connecting the two members  20 ,  30 . Bolt  40  is held in place by nuts  27   a ,  37   a , and bolt  44  is held in place by nuts  27   c , and  37   c . The nuts  27   a ,  37   a ,  27   c , and  37   c  may be tightened to adjust the spacing and relative positioning of members  20 ,  30 . Preferably, the members  20 ,  30  are in generally parallel alignment, and more preferably in parallel alignment. 
   Referring to  FIGS. 5 and 6 , the stud  16  is shown in more detail. The stud  16  is preferably metal, and more preferably aluminium. 
   Referring particularly to  FIG. 6 , a cross section of a stud  16  is shown. The stud comprises a front wall  100 , a back wall  102 , and side walls  104  and  106  forming a generally rectangular cross-section. A pair of inner walls  108 ,  110  extend between the side walls  104 ,  106 . The inner walls are preferably perpendicular to the side walls. A pair of flanges  112 ,  114  partially extend from the respective side walls  104 ,  106  toward the respective opposite side walls  106 ,  104 . The flanges  112 ,  114  are situated between the inner walls  108 ,  110  and the front wall  100 . The flanges  112 ,  114  are preferably perpendicular to the side walls, and aligned with each other. This arrangement provides three cavities  116 ,  118 ,  120  within stud  16 . 
   Referring to  FIG. 7 , the interface between the stud  16  and the cross member  18  is shown in more detail. Cross member  18  is oriented with the flanges  24 ,  34  extending from surface  22  toward stud  16 . The front wall  100  of stud  16  has been cut away to receive flat portions  26 ,  36  of cross member  18  in cavity  116 . It will be appreciated that this interface provides a flush surface between the cross member  18  and the stud  16 . 
   Referring to  FIG. 8 , the interface between stud  16   a  and cross member  18  is shown in more detail. Cross member  18  is oriented with the flanges  24 ,  34  extending from surface  22  toward stud  16 . The front wall  100  and flanges  112 ,  114  have been cut away to receive members  20 ,  30  in cavity  116 . The surfaces  22 ,  32  of the members  20 ,  30  abut flanges  112 ,  114 . The flanges  24 ,  34  of the members  20 ,  30  abut inner wall  110 . It will be appreciated that this arrangement also provides a flush surface between the cross member  18  and the stud  16   a.    
   From the preceding arrangement, it will be seen that when used to build a form, the stud  16  allows a cross member to be mounted flush by cutting away the front wall  100  and the side walls  104  and  106 . Still more clearance may be provided by cutting out the flanges  112 ,  114  for flush mounting as shown in  FIG. 8 . The inner walls  108 ,  110  maintain the strength of the stud when the front wall  100  and side walls  104  and  106  around the cavity  116  are removed. 
   In a preferred embodiment, the form  10  is assembled by placing three studs  16 ,  16   a  in a spaced apart arrangement as shown in  FIG. 9 . The two outer studs  16  are placed at opposite ends of the wood sheet  14 . The third stud  16   a  is placed in the middle of wood sheet  14 . Each of the studs  16 ,  16   a  is screwed into wood sheet  14 . Two cross members  18  are placed to span the studs  16 . The outer studs  16  are cut as shown in  FIG. 7  to mate with the end portions of cross members  18 . The middle stud  16   a  is cut as shown in  FIG. 8  to mate with the centre portion of cross members  18 . The cross members  18  are then attached to the studs  16 ,  16   a  using screws. 
   This arrangement is particularly suited for attaching a 4′×8′ sheet plywood. In this arrangement, the cross members are spaced 4′ from each other, and 2′ from the respective ends of the studs. Thus two such forms may be stacked by attaching the ends of the studs to obtain regular spacing of 4′ between cross members. 
   It will be recognized that providing a gap between flanges  112 ,  114  facilitates breaking apart of the stud to allow the arrangements of  FIGS. 7 and 8 . 
   With the arrangements shown in  FIGS. 7 and 8 , one size of screw may be used to attach both configurations. 
   It will be seen that a form as described in the preferred embodiment will be lighter than a wooden form. Further, the use of metal provides a more resilient form not as susceptible to damage and rot as one made of wood. 
   Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.