Abstract:
A clamp for interconnecting two components of a concrete forming apparatus such as metal form panels. A pivoting jaw is mounted around a pivot axis defined by a wedge for pivotal movement into and out of clamping engagement with a fixed jaw. A tooth or projection on a jaw engages corresponding alignment openings in the two form components to position and then hold the form components in the desired relationship.

Description:
[0001]     This application claims priority to U.S. Patent Application Ser. No. 60/662,075, filed Mar. 15, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates generally to concrete forming apparatus used in forming concrete structures and, more specifically, to a clamp, useful in interconnecting form panels of concrete forming apparatus, which includes a fixed jaw that carries a centering pin and a moveable jaw that receives the centering pin that is moved to and held in a clamping position by a tapered pin or wedge.  
         [0004]     2. Background of the Prior Art  
         [0005]     Concrete forming apparatus is in wide use in the construction of buildings, bridges, and other concrete structures. A common system for forming concrete structures uses a plurality of modular form components that are adapted to be assembled into a wide variety of configurations to conform to virtually any architectural requirement. Such forming apparatus components are typically made of metal so that they are strong enough to support the heavy weight of poured concrete and durable so that the components can be reused many times.  
         [0006]     One of the most commonly used configurations of such metal form components is a form panel that is used in forming substantially flat or curvilinear concrete surfaces, such as walls, foundations, pillars, and the like. Such metal concrete form panels have a face sheet which is in contact with the concrete being poured. A rearwardly extended flange is secured around the perimeter of the face sheet. A plurality of spaced apart stiffeners or ribs are tied to the perimeter flanges of the form panel on the opposite side of the face sheet from the wall or other structure being formed.  
         [0007]     Because of the variety in the size and shape of concrete structures formed using the form panel, it is advantageous to have the ability to interconnect the various components of the form panel in a wide variety of configurations without unduly multiplying the number of distinct components that are required to assemble the form panel of the desired diversity. Accordingly, a number of attempts have been made to design clamps or couplings for interconnecting components of form panel that are adjustable to fit a wide variety of configurations.  
         [0008]     One such coupling is described in the U.S. Pat. No. 5,713,687. The patent describes a coupling for interconnecting a horizontal panel at any desired position along a pair of vertical shoring posts. The coupling has a mouth formed of a stationary and moveable jaw. The moveable jaw is closed towards the stationary jaw by driving behind the moveable jaw a wedge-shaped tensioning member. The coupling mouth, when tensioned by the wedge, engages the vertical shoring post at the desired position. In an alternative embodiment, the wedge includes ribs that run at an angle with respect to the longitudinal axis of the wedge and which engage teeth on the moveable jaw to move it between an opened position and a clamped or tensioned position.  
         [0009]     Another such coupling device is described in U.S. Pat. No. 6,322,277. A clamp for interconnecting two components of a support apparatus such as components of a shoring apparatus for concrete foaming systems is disclosed. A clamp member having swing arm jaw is received for pivotal movement in a housing that is secured to one of the components. A plurality of flutes disposed at an angle to the pivot axis of the clamp member are received in coacting recesses in the housing. Axial movement of the clamp member pivots the swing arm and a coacting, moveable jaw toward a fixed jaw formed in the housing to releasably secure the clamp to the other component. The jaws of the clamp are designed to engage mating surfaces of a post used to support shoring apparatus.  
         [0010]     U.S. Pat. No. 4,881,716 describes a formwork lock for clamping two formwork panels together. Adjacent panels are assembled side-by-side with perimeter flange portions in contact engagement. The formwork lock has a pair of jaw members that are slideably moveable relative to each other between an open position where the perimeter flanges are received inside the jaws and a clamped position where the lock holds the perimeter flanges together. A wedge is used to hold the jaws in the clamped position.  
       SUMMARY OF THE INVENTION  
       [0011]     The invention consists of a clamp for releasably securing to each other a pair of form panels of a concrete forming apparatus. The clamp includes a pair of jaws that pivot relative to each other about a common pivot axis between a closed or clamping position, a partially open or unclamped position, and a fully open position. The first or fixed jaw has a pair of spaced-apart ear members, each of which has an opening centered on the common pivot axis. The second or pivoting jaw has a single ear member which also has an opening. The single ear member of the pivoting jaw is received inside the spaced-apart ears of the fixed jaw with the openings aligned.  
         [0012]     A wedge-shaped pin is received in the aligned openings with the longitudinal axis of the pin coincident with the pivot axis of the jaws. Movement of the wedge along its longitudinal axis will move the pivoting jaw between the unclamped position and the clamped position. Each of the end surfaces of the wedge has an impact surface which may be struck by a hammer or the like to bring the jaws to the clamped position or to release the jaws from the clamped position.  
         [0013]     As the jaws move toward the clamped position, the clamping end portions of the jaws opposite the opening approach each other. An aligning pin projects from the clamping end portion of the fixed jaw and in the direction of travel of the fixed jaw toward the clamped position. There is provided a receiving opening in the clamping end portion of the pivoting jaw that receives the aligning pin as the pivoting jaw moves toward the clamped position.  
         [0014]     An object of the present invention is to provide a clamp for interconnecting form panels of a concrete forming apparatus that is quickly and easily moveable between a released and a clamped position.  
         [0015]     Another object of the present invention is to provide a clamp for interconnecting form panels of a concrete forming apparatus which is durable and provides the requisite strength while being economical to manufacture.  
         [0016]     These and other objects of the invention will be made apparent to a person that is skilled in the art upon a review and understanding of this specification, the associated drawings, and the appended claims.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a perspective view of the clamp of the present invention in the closed position.  
         [0018]      FIG. 2  is a perspective view of the clamp of the present invention in the open position.  
         [0019]      FIG. 3  is a detailed view of the fixed jaw of the clamp of the present invention.  
         [0020]      FIG. 4  is a detailed view of the clamp of the present invention shown in the clamped position and the open position, including a pair of form panels of the forming apparatus.  
         [0021]      FIG. 5  is a detailed view of the pivoting jaw of the clamp of the present invention.  
         [0022]      FIG. 6  is a detailed view of the wedge of the clamp of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0023]     In the art of using formwork in the building of concrete structures, wet or plastic concrete is poured inside an assembly of formwork. The formwork is comprised of flat panels, panels that can be preformed to assume a curvilinear shape, forms that have a predetermined, fixed curvilinear shape, corner forms, and a variety of other forms for both general and specific applications such as are known in the art. These forms have a face sheet or the like against which the plastic concrete is poured and which, accordingly, determines the contour of the final concrete structure in the area of the form. In many instances, the individual forms are placed adjacent other forms and are held in place by clamps, fasteners, connectors, walers, shoring posts, and the like. By combining the variety of forms into a formwork assembly, virtually any desired shape of building structure can be formed.  
         [0024]     Plastic concrete is a heavy fluid that can exert very large forces on the formwork until the concrete has sufficiently cured. Accordingly, it is critical that the shoring and other support apparatus used to hold the forms in place be sufficiently strong to resist the forces of the plastic concrete. This has become of even greater importance in recent years with the increased use of modem concrete formulations which have a lower viscosity and allow higher heads of plastic concrete to be used in the formwork. It is also important that proper registry of the forms is achieved during initial assembly of the formwork and maintained throughout the pouring of concrete inside the formwork.  
         [0025]     Customarily, a plurality of form panels are used to form part of a concrete structure. The panels are arranged so that face sheets of the panels define the surface of the concrete structure being formed. Often, it is desired that the finished concrete structure be smooth and uniform, relatively free of form marks or the like that may result in the area of transition from one form to the adjacent form. The likelihood of such undesirable markings is reduced or eliminated if the forms are designed and manufactured to close tolerances and then assembled and held in place with the face sheets of adjacent panels in contact engagement along the length of the adjacent edges of the forms and the adjacent forms are oriented so that there is a smooth transition from one face sheet to the next. In the particular example of form panels having planar face sheets, a smooth transition is achieved if the face sheets are coplanar upon assembly. In another example wherein a cylindrical column is being formed using forms having a predetermined, fixed and constant radius of curvature, a smooth transition is achieved if the adjacent forms are oriented so that their shared radius of curvature defines a common central longitudinal axis. In the example of a planar form panel and a form of fixed curvature being used adjacent to each other, a smooth transition is achieved if the plane of the form panel is coincident with the tangent of the fixed curvature form along the adjacent edge.  
         [0026]     As seen in  FIG. 4 , the form panels  12  are held in place most typically be attaching the shoring and other support apparatus to the perimeter flanges  16   a,    16   b  or the reinforcing ribs (not pictured) or both. In the present invention, a clamp  20  is used to assist in proper registry of the form panels  12  during assembly and to hold the form panels  12  in the desired orientation and registry while the concrete is being poured and cured.  
         [0027]     In  FIGS. 1-6 , the form clamp  20  is used to connect individual form panels  12  into larger assemblies. The clamp  20  has a fixed jaw  22 , a pivoting jaw  24 , and a tapered pin or wedge  26 . When the wedge  26  is driven into the closed position, the wedge  26  brings the fixed jaw  22  and the pivoting jaw  24  together and aligns the panels together using the holes in the panels. The fixed jaw  22  has a clamping end portion  28  and a pivot axis or wedge-receiving end portion  30 . The end portion  30  includes a pair of parallel, spaced-apart ear members  32  and  34  forming a channel therebetween, each of which has a slot-shaped opening  36  and  38 , respectively. The pivoting jaw  24  has a clamping end portion  40  and a wedge-receiving end portion  42  which has an slot-shaped opening  44 . Upon assembly, the end portion  42  of the pivoting jaw  24  is positioned inside the ear members  32  and  34  of the fixed jaw  22  with the opening  44  put into substantial coaxial alignment with the openings  36  and  38 . The wedge  26  is inserted into the aligned openings  44 ,  36 , and  38 . The wedge  26  has a closing end  58  and an opening end  60 , which may include a button-strike surface  61 . ( FIG. 6 ). The pivoting jaw  24  is accordingly mounted on the fixed jaw  22  for pivotable and translatable movement relative thereto, moving the clamping end portion  40  of the pivoting jaw  24  toward and away from the clamping end portion  28  of the fixed jaw.  
         [0028]     An aligning pin or tooth  46  projects from the clamping end portion  28  of the fixed jaw  22  in the direction of travel toward the pivoting jaw  24 . ( FIG. 3 ). A corresponding opening  48  is formed in the clamping end portion  40  of the pivoting jaw  24 . ( FIG. 5 ). As the pivoting jaw  24  is moved toward the fixed jaw  22 , the tooth  46  will be received in the opening  48 .  
         [0029]     As seen in  FIGS. 2 and 4 , the wedge  26  allows for two different types of motion between the fixed jaw  22  and the pivoting jaw  24 . When the wedge  26  is in the open position (see  FIG. 2 ), the pivoting jaw  24  can translate and pivot outward and away from the fixed jaw  22 . The pivoting jaw  24  includes three stops  70 ,  72 , and  74  to limit the range of motion of the pivoting jaw  24 . In the open position, pivoting jaw  24  moves translatably away from the fixed jaw  22 . Once stop  70  on the pivoting jaw  24  has cleared the fixed jaw  22 , the pivoting jaw  24  can then rotate, which allows the clamp  20  to release the forms. In the open position, stops  72  and  74  limit the rotation of the pivoting jaw  24 . In the closed position, stops  70 ,  72 , and  74  limit the rotation of the pivoting jaw  24 .  
         [0030]     In  FIG. 4 , each form panel  12  has perimeter flanges  16   a  and  16   b  that include a plurality of corresponding openings  19  that, when a pair of form panels are oriented side-by-side with their face sheets in a coplanar relationship, are in coaxial alignment with the corresponding openings in the adjacent perimeter flange of the other panel. In use of the clamp  20 , a pair of form panels  12  are brought into closely adjacent positions with their face panels roughly parallel to and in alignment with each other. The clamp  20  is put into its fully open condition and positioned so that the tooth  46  in the fixed jaw  22  is at least roughly aligned with one of the openings in a first one of the panels along the adjacent perimeter flange  16 . The pivoting jaw  24  is pivoted toward the fixed jaw  22 , bringing the tooth  46  into the corresponding opening of the second one of the panels  12 . The wedge  26  is then moved in a direction to pivot the pivoting jaw  24  to the clamped position. The tooth  46  causes the corresponding openings in the two panels are brought into coaxial alignment. Use of two or more clamps  20  on the adjacent perimeter flanges  16  will ensure that the face sheets  14   a  and  14   b  of the two form panels  12   a  and  12   b  will be substantially coplanar.  
         [0031]     To secure the clamp  20  and the form panels  12 , a hammer or similar tool is used to impact the closing end  58  of the pin  26 , wedging the pin  26  in the openings  36 ,  38 , and  40  so that it will not be accidentally dislodged during use of the assembled form panels  12  in constructing a formwork assembly or during pouring and curing concrete in the formwork assembly. The clamp  20  can be easily released by impacting the opening end  60  of the pin  26  with a hammer or similar tool.  
         [0032]     In the preferred embodiment, the fixed jaw  22 , pivoting jaw  24 , and wedge  26  are made of investment cast steel. These parts may also be manufactured using alternate methods, including forging.  
         [0033]     Although the invention has been described with respect to a preferred embodiment thereof, it is to be also understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims.