Abstract:
A structural panel and method of making the same are disclosed wherein the structural panel has at least one frame member with receptor pockets extending therein. Ribs protruding from a lath are resiliently engaged within the receptor pockets thereby securing the lath against the frame member. A structural coating is secured to the lath thereby providing a labor-efficient, low-cost structural panel available for use for a number of different construction projects.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of International Application Number PCT/US02/27876 filed Aug. 30, 2002, which designates inter alia the United States and which claims the benefit of U.S. Provisional Application No. 60/315,994 filed Aug. 30, 2001. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to prefabricated structural panels which can be rapidly assembled to form buildings of various types. Specifically the invention relates to structural panels which incorporate a lath connected to frame members.  
         [0004]     2. Description of Related Art  
         [0005]     There is a widespread need for a building system that uses common construction materials which are readily available throughout the world and can be quickly erected with a minimal labor force, is cost effective and whose construction is capable of withstanding extreme environments. Such a building system must be environmentally friendly while appearing to be similar to traditional buildings and structures and also must be constructed of materials which wisely utilize limited natural resources.  
         [0006]     The demand for buildings, especially homes, in many third world countries is high. Additionally, current building methods many times are so slow, outdated and so labor intense that there is no way to satisfy the existing demand. While structures made from stone, block and concrete materials are time-tested and have proven their effectiveness worldwide, a change in building design must occur in order to keep up with this high demand. Portland cement, a common natural resource, has been used throughout the world for over two thousand years to produce concrete, mortar plaster and stucco. Steel has been used and relied upon since the early 1800s. Both portland cement and steel are cost effective and readily available from producers worldwide.  
         [0007]     Therefore, a building utilizing a light gauge steel frame that can be covered with a cement exterior/interior coating and that would closely resemble currently existing buildings is desirable.  
         [0008]     There are existing building systems that use light gauge laths, meshes, expanded metal or similar materials to build various types of stucco or plaster covered structures. All of these systems utilize discrete mechanical fasteners to attach the lath to the frame and must be used over a solid substrate such as plywood to provide adequate strength and to provide a material to which the fasteners can be attached. Once the lath is fastened, stucco or plaster, each of which is considered to be a cementitious coating, is applied in a series of layers over the substrate. The lath, once embedded in the cementitious coating, acts together with the coating to provide a structure having more strength using a design technique which offers a greater level of flexibility.  
         [0009]     There are different types of existing commercial laths. The first type of lath is diamond mesh lath. It is manufactured out of thin sheets of metal that are slit with knives and stretched apart. The lath pattern resembles uniformly spaced small diamond shapes. The diamond mesh lath must be fastened to a substrate with nails or screws and must be used in conjunction with a solid surface because this diamond mesh lath is inherently flexible. The diamond shaped pattern allows the lath not only to be formed for contours but also provide a smooth surface desirable for ornamental work and smooth plaster finishes.  
         [0010]     A second type of lath is a self-furring lath which may have a dimpled diamond or high ribbed surface that spaces the lath away from a mounting surface. These self-furring laths enable a structural coating to encapsulate the lath such that the lath is in the middle of the structural coating thereby providing greater strength. Self-furring laths, just as the diamond mesh lath, must be attached to a solid substrate such as plywood or water-resistant gypsum board using nails or screws.  
         [0011]     A third type of lath is a lath having diamond patterns and having continuous flat ribs of steel which has a unique shape for added strength and support. This type of lath can be used over an open frame and does not require attachment to a solid substrate. However, this type of lath is limited for use on spans no greater than 16 inches and is not self-furring. In particular, one typical lath includes three 16-inch flat ribs spaced on 2-inch centers which run the continuous length of the lath. However, once again, these ribbed laths must be mechanically fastened to one another using discrete fasteners.  
         [0012]     Finally, a flat-ribbed lath having a diamond shape in a reverse herringbone pattern may have V-shaped ribs that run the length of the lath. In one instance, ⅜-inch V-shaped ribs are spaced at 4½ inch intervals and provide structural support on open framed cavities having framing members spaced less than 16 inches apart. However, once again this type of lath must be mechanically fastened using discrete fasteners.  
         [0013]     Each of these laths when used to cover a 2-foot by 8-foot area, requires between 36-45 fasteners. Not only do these fasteners add to the overall material costs, but also the time required to apply these fasteners increases the cost of labor and the overall time of construction.  
         [0014]     Light gauge framing components made from coils of thin metal having various thicknesses and widths have existed for more than forty years. Such framing components typically consist of a web and a flange extending therefrom.  
         [0015]     European Patent No. 159,764 issued to Illinois Tool Works on Oct. 30, 1985 shows a fastener for installing a sheet such as a lath spaced from a support. The lath described therein requires discrete mechanical fasteners.  
         [0016]     Japanese Patent No. 03,290,555 issued to Adachi et al. on Dec. 20, 1991 shows a method for fixing an inner wall. This patent discloses a means of attaching a wood beam such as a ceiling or floor beam in a steel fitting means. There is neither a teaching nor a discussion of a lath.  
         [0017]     Japanese Patent No. 03,286,029 issued to Misaka on Dec. 17, 1991 illustrates a steel underground wall and method of construction. This patent discloses a seismic reinforcement using a steel grid composed of beams, and neither teaches nor suggests the use of a lath.  
         [0018]     European Patent No. 434869 issued to International Building Systems, Inc. on Dec. 15, 1993 illustrates a steel stud and precast panel which requires a fastening means before the introduction of concrete over a steel stud.  
         [0019]     Japanese Patent No. 06,158,858 issued to Harino et al. on Jun. 7, 1994 illustrates a form for concrete foundation and describes a means of pouring concrete into a panel. This patent neither teaches nor discusses the use of a lath.  
         [0020]     Japanese Patent No. 08,270,142 issued to Miyata on Oct. 15, 1996 illustrates a steel stud for a partition wall used in a coupling system for holding fireproof boards. There is neither a teaching nor a discussion of the use of a lath.  
         [0021]     Japanese Patent No. 09,279,806 issued to Hosoda on Oct. 28, 1997 discloses a method for fixing a rib lath utilizing a means for fastening a lath including screw attachments to pierce through the lath at recess points.  
         [0022]     Japanese Patent No. 10,161,189 issued to Hosoda on Jun. 23, 1998 illustrates a ribbed lath used as a form. This patent neither teaches a self-setting lath system nor suggests that the lath be applied to a stud.  
         [0023]     Japanese Patent No. 10,237,994 issued to Shiozo et al. on Sep. 8, 1998 discloses a concrete panel made up of a lath and steel studs and a method utilizing heat to attach the lath to the steel studs.  
         [0024]     A design for applying a lath to a frame is desired which requires no discrete fasteners for permanent connection and requires no solid substrates upon which to secure the lath.  
       SUMMARY OF THE INVENTION  
       [0025]     A first embodiment of the subject invention is directed to a lath for use with a frame member for a structural panel comprising a generally planar sheet having a front side and a back side with a plurality of ribs formed within the sheet. The ribs protrude from the back side of the sheet and each rib has a profile with a first side and a second side which diverge from one another as they extend away from the back side and then converge. The maximum height of a rib occurs at the place of maximum divergence and a plurality of slats extends through the sheet for adapting the sheet to receive and retain thereupon a structural coating.  
         [0026]     A second embodiment of the subject invention is directed to a structural panel comprising at least one frame member having a longitudinal axis and a plurality of receptor pockets extending within the frame member in a direction generally perpendicular to the longitudinal axis. A lath is connected to the at least one frame member and the lath has a plurality of resilient ribs extending therefrom. The ribs resiliently engage corresponding receptor pockets within the at least one frame member to secure the lath to the at least one frame member.  
         [0027]     A third embodiment of the subject invention is directed to a method of making a structural panel utilizing at least one frame member having a longitudinal axis and a plurality of receptor pockets extending within the frame member in a direction generally perpendicular to the longitudinal axis. A lath having a plurality of resilient ribs extending therefrom is adapted to resiliently engage corresponding receptor pockets within the at least one frame member. The method comprises the steps of aligning the ribs of the lath with matching receptor pockets in each of the frame members, and urging each rib within the matching receptor pocket of the frame member until each rib snaps into position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]      FIG. 1  show a front elevation view of a section of a ribbed channel lath in accordance with the subject invention;  
         [0029]      FIG. 2  is a side view of the lath illustrated in  FIG. 1 ;  
         [0030]      FIG. 3  is an exploded side view of the lath in position to be mounted upon a frame member;  
         [0031]      FIG. 4  is a side view of the lath mounted upon the frame member;  
         [0032]      FIG. 5  is an exploded view of the lath mounted upon a frame member with a structural coating spaced therefrom;  
         [0033]      FIG. 6  is a side view of the components illustrated in  FIG. 5  but assembled;  
         [0034]      FIG. 7  is a side view of the assembled frame member, lath and base structural coating having exploded therefrom a screen and a supplemental structural coating;  
         [0035]      FIG. 8  is a side view of the elements illustrated in  FIG. 7  but assembled;  
         [0036]      FIG. 9  is a perspective view of a structural panel in accordance with the subject invention;  
         [0037]      FIG. 10  is a perspective view of an enlarged portion circled in  FIG. 9 ;  
         [0038]      FIG. 11  is an exploded side view of an intermediate barrier, a lath and frame member;  
         [0039]      FIG. 12  is a side view of the intermediate layer and lath assembled on a frame member; and  
         [0040]      FIGS. 13A-13G  illustrate sketches of different rib profiles. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]     The present invention is a light gauge lath and framing system to provide a structured panel for roofs, floors, ceilings, foundations, basement walls, verandahs, decks, fences and interior and exterior walls in building construction. The structural panel in accordance with the subject invention can be assembled without the use of discrete fasteners and is able to stand between frame members without the use of a solid substrate.  
         [0042]     Directing attention to  FIGS. 1 and 2 , a lath  10  is made up of a generally planar sheet  15  having a front side  17  and a back side  19 . A plurality of ribs  20  are formed within the sheet  15 . Each rib  20  protrudes from the back side  19  of the sheet  15 . Furthermore, each rib  20  has a profile with a first side  22  and a second side  24  which diverge from one another as they extend away from the back side  19  and then the first side  22  and the second side  24  converge to intersect. Each rib has a maximum height H which occurs at the place of maximum divergence of the first side  22  and the second side  24 . Each rib  20  may extend across the lath in an interrupted pattern such that each rib  20  is a plurality of protrusions.  
         [0043]     A plurality of slats  25  extends through the sheet  15  for adapting the sheet  15  to receive and retain thereupon a structural coating (not shown). The sheet  15  may be constructed from a thin, pliable material such that the ribs  20  are resilient and may be compressed to reduce the maximum height H and snapped into apertures or slots in a frame member. The sheet  15  may be made from any number of materials that are resilient and provide the desired shape such as metal, plastic and carbon fiber composites.  
         [0044]     The sheet  15  has a plurality of segments  30  (distinguished by reference numbers  30   a - 30   g ) with the slats  25  therein wherein the slats  25  within adjacent segments, segments  30   a  and  30   b  for example, are oriented differently to securely engage any structural coating (not shown) that may be applied to the sheet  15 . As illustrated in  FIG. 1 , the slats  25  within a segment  30   a  are parallel to one another. The sheet  15  has a longitudinal axis LL and each slat  25  lies along a line to define a slat vertical angle A with the longitudinal axis LL. The slat vertical angle A formed by the slats  25  in one segment  30   a , for example, is equal and opposite to the slat vertical angle A formed by the slats  25  in an adjacent segment  30   b  for example. Additionally, each segment  30   a - g  of slats  25  may form a slat planar angle B with the longitudinal axis LL of a lath  10 . The slat planar angle B of the slats  25  in one segment for example, segment  30   a  may be equal to and opposite the slat planar angle B formed by the slats  25  in an adjacent segment, for example, segment  30   b.    
         [0045]     A plurality of divots  40  may be formed within the front side  17  of the sheet  15  to provide protrusions from the back side  19  of the sheet  15 , such that the sheet  15  may be spaced from any flat surface upon which it may be applied.  
         [0046]     A structural coating (not shown) may be applied to the lath and, for that reason, each rib  20  may have a plurality of holes  45  extending therethrough to provide pressure relief to any structural coating that may be applied to the sheet  15 .  
         [0047]      FIGS. 3 and 4  illustrate the manner in which the lath  10  may be secured to a frame member  100 . As illustrated in  FIG. 9 , a lath  10  may be secured to a plurality of frame members  100  to form a structural panel  200 .  
         [0048]     Directing attention to  FIGS. 3 and 4 , the structural panel  200  ( FIG. 9 ) may be comprised of, at least one frame member  100  having a longitudinal axis LF and a plurality of receptor pockets  105  extending within the frame member  100  in a direction generally perpendicular to the longitudinal axis LF.  
         [0049]     The lath  10  is connected to the frame member  100  through the plurality of resilient ribs  20  extending therefrom. The ribs  20  resiliently engage corresponding receptor pockets  105  within the frame member  100  to secure the lath  10  to the frame member  100 . Each receptor pocket  105  extends from a first side  102  of the frame member  100  and the lath  10  is secured to this first side  102 .  
         [0050]     The receptor pockets  105  may extend from both the first side  102  and an opposing second side  104  of a frame member  100 . Under these circumstances, the lath  10  may be secured to the first side  102  of the frame member  100  while a second lath ( 10  in  FIG. 4 ) may be secured to the second side  104  of the frame member  100 .  
         [0051]     As illustrated in  FIGS. 5 and 6 , a base structural coating  150  may be applied to the front side  17  of the lath  10 . The structural coating  150  penetrates through the slats  25  ( FIG. 1 ) and the receptor pockets  105 . Since the ribs  20  of the lath  10  must be compressed to snap within the receptor pockets  105  of the frame member  100 , once the lath  10  is secured to the frame member  100 , when the structural coating  150  is applied, the coating  150  not only permeates the slats  25  but furthermore fills the remaining volume within each receptor pocket  105 . The structural coating  150  hardens within a receptor pocket  105  and the rib  20  becomes permanently secured within the receptor pocket  105  because the hardened structural coating  150  prevents the rib  20  from compressing, which would be required to remove the rib  20  from the receptor pocket  105 . This provides a permanent connection for the ribs  20  of the lath  10  into the receptor pockets  105  because of the unique one-way fitting design of the panel.  
         [0052]     The base structural coating  150  may be stucco or plaster. The lath  10  may be metal and the frame member  100  may be light gauge steel.  
         [0053]     Directing attention to  FIG. 7 , the structural panel may further include a structural mesh  170  which may be embedded within the base structural coating  150 . In particular, in areas that are prone to seismic activity and extreme whether conditions, the structural mesh  170  applied to the base structural coating  150  may reduce the chance of cracking and increase the overall strength of the structural panel  200  ( FIG. 9 ). The structural mesh  170  may be adhered, fabricated or attached to each lath  10  in an offset pattern. The offset pattern allows for the structural mesh  170  to overlap other laths  10  by creating a uniform covering which may overlap for example by as much as two inches on each lath  10 .  
         [0054]     The structural mesh  170  may be supported from the top of the partially constructed structural panel  200  and a person applying the base structural coating  150  may lift the structural mesh  170  up while the base structural coating  150  is being applied. Once an area has been coated with the base structural coating  150 , the structural mesh  170  is then released and lightly pressed into the base structural coating  150 , which has not yet solidified. The structural mesh  170  may be pressed below the surface of the base structural coating  150 . The texture of the structural mesh  170  will increase the bond for any subsequent coating which may be added and furthermore will increase the strength of the base structural coating  150  and reduce the chance of cracking, surface spalling or peeling. In addition to the structural mesh  170 , it is also possible to include a supplemental structural coating  180  over the structural mesh  170  and over the base structural coating  150 . This supplemental structural coating  180  may be formulated to provide a desirable exterior finish.  FIG. 8  illustrates the elements of  FIG. 7  assembled. The frame member  100  has attached thereto the lath  10 , the base structural coating  150 , the structural mesh  170  and the supplemental structural coating  180 .  
         [0055]      FIG. 9  illustrates a structural panel  200  in which frame members  100  are secured to mounting members  205 ,  210 . Additionally, the lath  10  is secured to the frame members  100 , the base structural coating  150  is secured to the lath  10  and the supplemental structural coating  180  is secured to the base structural coating  150 . It should be understood that the structural mesh  170  ( FIG. 7 ) may also be included, however, for clarity is not illustrated in  FIG. 9 .  FIG. 10  illustrates an enlargement of the portion encircled in  FIG. 9  and more clearly illustrates the details of the lath  10  and its attachments to the frame members  100 .  
         [0056]     The base structural coating  150  and the supplemental structural coating  180  may be applied using one of at least two methods. In a first method a hand trowel may be used to apply the structural coatings. Using this method, the structural coatings may be selectively applied with effectiveness. In a second method, the structural coatings may be applied by machine spraying.  
         [0057]     Directing attention to  FIG. 11  when the structural coatings are applied by spraying, it is necessary to install a mesh  215  between the lath  10  and the frame member  100  to provide a backdrop. The purpose of this backdrop mesh  215 , which may, for example, be made of fiberglass or of a carbon fiber composite, is to catch any structural coating spray that goes through the openings of the lath  10 . This backdrop mesh  215 , as illustrated in  FIG. 11 , is placed between the frame member  100  and the lath  10  is placed over the backdrop mesh  215  and against the frame member  100  such that the ribs  20  of the lath  10  pinch and secure the backdrop mesh  215  within the receptor pockets  105  of the frame member  100 . When the lath  10  is pressed into the receptor pockets  105  of the frame member  100 , the backdrop mesh  215  becomes permanently attached between the lath  10  and the frame member  100  and at the same time is drawn taut forming another medium upon which the base structural coating  150  may adhere. Although the mesh  215  is illustrated with a geometry generally shaped to the receptor pocket  105 , it should be appreciated that the mesh  215  may also be a flat sheet and the force of the ribs  20  will conform the mesh  215  to the shape of the receptor pocket  105 . The separated parts illustrated in  FIG. 11  are shown assembled in  FIG. 12 .  
         [0058]     In lieu of, or in addition to the structural coatings being placed over the lath  10  and into the receptor pockets  105  of the frame members  100  to increase the strength between spans, as illustrated in  FIG. 12 , a reinforcement bar  220  may be positioned within the ribs  20  of the lath  10  to lock the lath  10  within the frame member  100  and to provide additional structural stiffness to the structural panel  200 . The use of reinforcement bars  220  inside the receptor pockets  105  furthermore increases the strength and reduces the side-to-side rotational movement while at the same time provides a permanent connection of the lath  10  into the receptor pockets  105  because of the unique one-way fitting design in the panel  200 . This application would be typical in a floor application where the live and dead building loads are considerably higher than the loads to which walls, ceilings and roofs are subjected.  
         [0059]     In areas of dramatic changes in temperature, a thermal break may be introduced between the lath  10  and the frame member  100 . Referring again to  FIGS. 11 and 12 , while the backdrop mesh is indicated by reference number  215 , an element having a very similar appearance could be used as the thermal break. For that reason, reference number  225  listed in parentheses will also be used in  FIGS. 11 and 12  to indicate that when a thermal break  225  is utilized, it will appear similar to and be secured in a similar way as the backdrop mesh  215  illustrated therein. The thermal break  225  positioned between the lath  10  and the frame member  100  provides a thermal barrier that will disrupt any conductive heat flow from the lath  10  to the frame member  100 . The thermal break  225  may be comprised of a liquid gasket applied over the lath  10  or, in the alternative, may be comprised of a one-piece gasket secured to the frame member  100 . As shown the thermal break  225  has a shape similar to that of the frame member  100  and receptor pockets  105 . However, the thermal break  225  may also be a non-conforming sheet conformed to the receptor pockets  105  by the force of the ribs  20 . Although the thermal break  225  will be compressed between the lath  10  and the frame member  100 , the thermal break  225  may also be secured to the frame member  100  using adhesive.  
         [0060]     Returning to  FIGS. 3 and 4 , a method of making the structural panel  200  herein described, comprises the step of aligning the ribs  20  of the lath  10  with the matching receptor pockets  105  at each frame member  100  and then urging each rib  20  within the matching receptor pocket  105  of the frame member  100  until the rib  20  snaps into position. Using a plastic mallet or a rolling machine, the lath  10  is pushed into the frame member  100 . Directing attention to  FIGS. 5 and 6 , the method may also comprise the step of coating the lath  10  with a base structural coating  150 . Furthermore, after the ribs  20  of the lath  10  are positioned within the receptor pockets  105  of the frame member  100 , reinforcement bars  220  ( FIG. 12 ) may be inserted within the ribs  20  to lock the ribs  20  within each receptor pocket  105 .  
         [0061]     Each lath  10  has a plurality of fastening grooves  27  ( FIG. 1 ) with holes  29  therein, to hold screws used to mount the lath  10  to a structure during shipping only. Optionally, additional screws can be applied at the four corners of the structural panel  200  to improve the strength of the panel  200  when shipping and handling. It should be noted, however, that such screws are not required for attaching the lath  10  to the frame member  100 .  
         [0062]     The subject invention provides a structural panel  200  having laths  10  which are connected to frame members  100  without the use of any discrete fasteners. Pressing the lath  10  into the frame member  100  is a more cost-effective method than attaching a lath  10  to the steel frame  100  since there are no discrete fasteners to install. Furthermore, installation is safer and labor costs are reduced.  
         [0063]     The lath  10 , in accordance with the subject invention, provides a continuous surface for structural coatings to be applied. When these ribs  20  of the lath  10  are integrated within the receptor pockets  105  of the frame member  100 , the increase in structural integrity keeps the components from side-to-side and rotational movement.  
         [0064]     The frame member  100 , as illustrated in  FIG. 9 , may be a C-shaped member comprised of a base  110  having a flange  112  on one side of the base  110  and an opposing flange  114  on the opposite side of the base  110 . As illustrated in  FIG. 9 , the frame member  100  includes receptor pockets  105  in only flange  114 . Under these circumstances, the lath  10  may be applied only to a single side of the frame member  100 . In the alternative and as illustrated in  FIG. 3 , it is possible for the frame member  100  to have receptor pockets  105  on both sides of the frame member  100  thereby, as further illustrated in  FIG. 4 , permitting lath  10  to be applied to both sides of the frame member  100 .  
         [0065]     The structural panel  200 , in accordance with the subject invention may have frame members spaced over 24″ at canter, thereby reducing the number of components for a panel which typically has frame members on 16″ centers.  
         [0066]     The figures have illustrated a rib  20  extending completely across the lath  20  and receptor pockets  105  extending completely across the frame member  100 . It is possible for the rib  20  to extend across the lath  10  in an interrupted pattern to mate with a receptor pocket  105  that extends across the front  102  of the frame member  100  or to mate with receptor pockets  105  that are positioned on the front  102  of the frame member  100  to correspond with the locations of the interrupted pattern ribs.  
         [0067]     Furthermore, the ribs  20  so far discussed have been in the general shape of a tear drop. A number of other rib shapes may be used in as much as these ribs may be snapped into the frame member  100 .  FIGS. 13A-13G  illustrate a few such rib  320  shapes. In each of these shapes, the first side  322  diverges from the second side  324  and then converges. As a result, these ribs  320  may snap into an appropriately sized receptor pocket located in the frame member. As illustrated in  FIGS. 13F and 13G , each rib  320  may resemble a barb.  
         [0068]     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.