Patent Publication Number: US-7908809-B2

Title: Screeding apparatus and system for a three dimensional panel

Description:
RELATED APPLICATION 
     This application relies upon U.S. Provisional Patent Application Ser. No. 60/870,039, filed Dec. 14, 2006, the contents of which are incorporated herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to an apparatus and system for screeding a three dimensional panel and in greater detail the apparatus and system includes a screed clip for securing a guide bar to the panel for screeding a cementitious coating to a substantially uniform finish and level. 
     BACKGROUND 
     Buildings have commonly been formed from various prefabricated elements. One common prefabricated building element includes a three dimensional panel used to form portions of a finished structure. The paneled element typically includes a three-dimensional grid body having an insulating body formed within the grid, which is then finished with an application of a cementitious coating such as shotcrete. 
     In greater detail, the three dimensional panel includes two parallel welded wire grid mats and associated web wires holding the wire grid mats at a distance from one another. An insulating body is arranged between the wire grid mats. The web wires extend through the insulating body and support it between the wire grid mats. To improve the adhesion of the concrete to the insulating body, the insulating body may include roughened surfaces. A cementitious coating of shotcrete is then applied to the panels to complete the structure. 
     Unfortunately, while the panel process of building provides a strong and quick method for forming a structure, it does require a relatively skilled and experienced craftsperson to hand finish the applied concrete to a desired thickness and finish. Thus, it would be desirable to accelerate the building process and reduce costs if the finishing process of applying the shotcrete could be done quickly using unskilled labor. 
     SUMMARY 
     The present invention includes both an apparatus and system for screeding a cementitious coating applied to a three dimensional panel. The screeding system includes a screed clip for securing a guide bar to the panel for screeding a cementitious coating to a substantially uniform finish and level. The clips are used in combination and in series to support a guide bar. The clips are attached to the wire grid mats of the three dimensional panels to enable a less than skilled laborer to finish a cementitious coating applied to the panel. 
     In greater detail, the screed clip of the present invention is used in combination with a three dimensional panel. The three dimensional panel is formed from two opposed parallel welded wire grid mats, an insulating body arranged between the wire grid mats and associated web wires holding the wire grid mats at a distance from one another. The screed clip includes a first opposed arm and a second opposed arm extending from a base portion. The arms include at their end portions an attachment mechanism for engaging a rung of wire of the welded grid mat. An additional attachment mechanism may be located at the base portion for engaging the wire of the welded grid mat. The clip further includes a support member extending up from the base portion for engaging a guide bar. 
     The wire attachment mechanism can include a slotted groove for engaging the wire and a return formed at the base of the slotted groove for securely attaching the clip to the wire grid mat. The attachment mechanism may be further comprised of friction fit notches, clips, biased members, hooked members, tensioned members and combinations thereof. 
     The support member of the clip may include a slide portion upon which the guide bar rests and substantially parallel arms extending up from the slide portion and perpendicular to the grid mat for restricting the lateral movement of the guide bar. The arms may extend up to a length that is less than the circumference of the guide bar such that only the guide bar engages the screed. 
     An additional embodiment includes a kit for screeding a cementitious coating applied to a three dimensional panel. The kit includes a guide bar formed from such materials as a fiber reinforced polymer. The kit further includes a plurality of screed clips attached to the welded grid mat in series for supporting the guide bar throughout the length of the guide bar. 
     A further embodiment includes a method of screeding a cementitious coating applied to a three dimensional panel. The method includes attaching to the welded grid mat a plurality of screed clips comprising a first opposed arm and a second opposed arm extending from a base portion, a wire attachment mechanism located at an end portion of each arm for engaging a wire of the welded grid mat and a support member extending up from the base portion, wherein the screed clips are attached in series. 
     The method further includes inserting a guide bar through the plurality of screed clips attached in the series and applying a cementitious coating to the panel. The method then includes screeding the cementitious coating applied to the panel to a finish and thickness as directed by the guide bars. Additionally, the method may include removing the guide bars after screeding the cementitious coating. 
    
    
     
       DRAWINGS 
       In the drawings: 
         FIG. 1  is an interior cross sectional view of a three dimensional panel having an insulating foamed body formed within, and further including a shotcrete finished applied to the exterior portion of the panel; 
         FIG. 2  illustrates a frontal view of the present screed clip including the opposed arms extending out from the base portion having attachment mechanisms within both the arms and base portion; and the support member extending up from the base portion; 
         FIG. 3  depicts a side view of the clip as is would appear when perpendicular to the attached wire of the wire grid mat; and 
         FIG. 4  illustrates a top view of the present screed clip attached to the wire grid mat. 
         FIG. 5  illustrates a three dimensional view of an embodiment of the present screed clip minus the support member. 
         FIG. 6  is a three dimensional view of the support member including a slide portion. 
         FIG. 7  is a line drawing showing the present screed clip including the support member and the base portion. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed is an apparatus and system for screeding a cementitious coating applied to a three dimensional panel. The system includes a screed clip for securing a guide bar to the panel&#39;s wire grid mat for enabling a less than skilled laborer to screed a cementitious coating to a substantially uniform finish and level. 
     The screed clips of the present system are used in combination with three dimensional panels comprised of a three dimensional welded wire frame utilizing a truss for stress transfer and stiffness. The surface of the wire grid mat, in an embodiment, is comprised of about 2 inch square welded wire mesh patterns of intersecting longitudinal and transverse wires having the same diameter. The three dimensional panel is formed from two such wire grid mats sandwiching an insulating body arranged between the wire grid mats and associated web wires holding the wire grid mats at a distance from one another. 
     The screed clip of the present system includes a first opposed arm and a second opposed arm extending out from a base portion of the clip running parallel to the wire grid. The arms include at their end portions farthest from the base portion an attachment mechanism for engaging a rung of wire of the welded grid mat. The clip further includes a support member extending up from the base portion for engaging and holding a guide bar in place. 
     The present invention further includes a kit for screeding a cementitious coating applied to a three dimensional panel. The kit provides a guide bar formed preferably from a substantially non-corrosive material, such as a fiber reinforced polymer or stainless steel. An example guide bar includes a fiber reinforced polymer bar having a diameter of ⅜ inches, this diameter was found to provide a degree of stiffness; allowing the bar to break before it bends. Of course, the guide bar is not limited to any one type of material or diameter, but can be chosen for the performance characteristics of the material, and is not limited to only non-corrosive materials. Desirable characteristics may include the ability to withstand corrosion, weight, and substantial lack of flexibility. The guide bar should be able to direct a screed to create a finish having a substantially even depth and appearance. 
     The kit further includes a plurality of screed clips attached to the welded wire grid mat in series for supporting the guide bar throughout the length of the guide bar. In this configuration, the screed clips are lined up in a series and in a row throughout the length of a particular guide bar. Each guide bar in this embodiment has its own respective series of screed clips attached to the grid mat. The grid mat may have a plurality of screed clip series attached in rows on the grid mat with their respective guide bars attached thereto. 
     A further embodiment includes a method of screeding a cementitious coating applied to the three dimensional panel. The method includes attaching to the welded grid mat a plurality of screed clips via the attachment mechanism on each clip in a series on the grid mat. The method further includes inserting a guide bar through the plurality of screed clips attached in the series and applying a cementitious coating to the panel. The application of the cementitious coating can be done through any know method including dry or wet shotcrete applications to a prescribed thickness. The method then includes screeding the cementitious coating applied to the panel to a finish and thickness as directed by the guide bars. Additionally, the method may include removing the guide bars after screeding the cementitious coating. 
     Referring now in greater detail to the drawings in which like numerals indicate like items throughout the several views,  FIGS. 1-7  depict the present apparatus and system for screeding and finishing a cementitious coating of a three dimensional in the various embodiments of the present invention. 
       FIG. 1  depicts an interior cross sectional view of a three dimensional panel  2  comprising an insulating foamed body  4  formed within, and further including a shotcrete finish  6  applied to the exterior portion of the panel  2 .  FIG. 1  further depicts the welded wire grid mats  8  and the individually welded internal truss wires or diagonals  10  extending through the panel&#39;s foamed core  4  between each grid mat  8 . The truss wires  10  are welded continuously with the grid mats  8  into a triangulated truss system for increased panel strength. 
       FIG. 2  illustrates a frontal view of the present screed clip  12  including the opposed arms  14 ( a - b ) extending out from the base portion  24  having attachment mechanisms  16  within the arms and base portion. The support member  26  extends up from the base portion  24  for engaging the guide bar  28 . As shown in  FIG. 2 , the attachment mechanism  16  may also be located at the base portion  24  for engaging the wire  18  of the welded grid mat  8 . The wire attachment mechanism  16  can include a slotted groove  16  for engaging the wire  18  and a return  20  formed at the base of the slotted groove  16  for securely attaching the clip  12  to the wire grid mat  8 . 
     The present clip  12  is not limited to any certain number of attachment mechanisms  16  and it is contemplated that two or more attachment mechanisms  16  may be incorporated into the clip  12 . For example, the opposed extended arms  14  ( a - b ) may each be attached to two adjacent wires  18  or the clip  12  may extend over three rows of wires such that each arm  14 ( a - b ) and the base portion  24  are attached to individual wires  18 . Of course there are other configurations involving more wires  18 . The attachment mechanism  16  may be further comprised of friction fit notches, clips, biased members, hooked members, tensioned members and combinations thereof. 
     The support member  26  of the clip  12  may include a slide portion  30  upon which the guide bar  28  rests and substantially parallel arms  22  extending from the slide portion  30  for restricting the lateral movement of the guide bar  28 . As shown in  FIG. 2 , the arms  22  may extend up to a length that is less than the circumference of the guide bar  28  such that only the guide bar  28  engages the screed. 
       FIG. 3  depicts a side view of the screed clip  12  as is would appear when perpendicular to the wire  18  it is attached to on the wire grid mat  8 . The side view of  FIG. 3  illustrates one of the parallel arms  22  extending from the slide portion  30  for restricting the lateral movement of the guide bar  28  and the end portion of one of the opposed arms  14  of the clip  12 . Further illustrated is a wire  18  of the wire grid mat  8  engaged with the attachment mechanism  16 . 
       FIG. 4  illustrates a top view of the present screed clip  12  attached to the wire grid mat  8  of the panel  2 . As shown in  FIG. 4 , the guide bar  28  is engaged with the support member  26  and the wires  18  of the grid mat  8  are engaged with the attachment mechanisms  16  on the respective opposed arms  14 ( a - b ). 
       FIG. 5  illustrates a three dimensional view of an embodiment of the present screed clip  12  minus the support member  26  including the opposed arms  14 ( a - b ) extending out from the base portion  24  having attachment mechanisms  16  within the arms  14 ( a - b ). The base portion  24  is shown having an insert receiving section  31  for receiving and securing the support member  26  to the base portion  24 . In one embodiment the insert receiving section  31  may be configured such that the support member  26  may rotate freely within the insert receiving section  31 . However, the insert receiving section  31  may have various configurations for attaching the support member  26  to the base portion  24 . 
       FIG. 6  is a three dimensional view of the support member  26  including a slide portion  30  upon which the guide bar  28  rests and substantially parallel arms  22  extending from the slide portion  30  for restricting the lateral movement of the guide bar  28 . The arms  22  may extend up to a length that is less than the circumference of the guide bar  28  such that only the guide bar  28  engages the screed. 
     Further shown in  FIG. 6 , is the embodiment comprising the support insert  32  which is operatively configured to fit within the within the insert receiving section  31 . The support insert  32  may be rotatively configured within the within the insert receiving section  31  of the base portion  24  to accommodate the various angles in a building, such as roof angles. The support member  26  may also be configured to various lengths to accommodate different concrete thicknesses. For example, the support member may have a length to accommodate concrete thicknesses of 1.5, 2, and 2.5 inches. Of course other thickness are contemplated and a combination of lengths may be used together. 
       FIG. 7  is a line drawing showing the present screed clip  12  including the support member  26  and the base portion  24 , wherein the support insert  32  of the support member  26  is operatively configured to fit within the insert receiving section  31  of the base portion  24 . 
     While applicant has set forth embodiments as illustrated and described above, it is recognized that variations may be made with respect to disclosed embodiments. Therefore, while the invention has been disclosed in various forms only, it will be obvious to those skilled in the art that many additions, deletions and modifications can be made without departing from the spirit and scope of this invention, and no undue limits should be imposed except as set forth in the following claims.