Abstract:
An improved screed guide/control joint and clip for the placement of concrete in concrete slabs on a plurality of different surfaces, the clip accommodating different sized screed guides to accommodate different depths of concrete pours, the screed guide/control joint inhibiting water passage, impeding growth of weeds in the joint, and having improved lateral flexibility to the expansion and contraction of the concrete, the screed guide also allowing placement of conduits within the cover portion of the channel cavity of the screed guide.

Description:
RELATED APPLICATIONS 
     Applicant claims the benefit of provisional application Ser. No. 62/176,453, filed Feb. 20, 2015. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved screed guide/control joint and clip, which are utilized in the placement of concrete in concrete slabs and establishing control joints, the screed guide/control joints providing precise placement of the concrete in concrete slabs and its leveling. 
     2. Description of the Prior Art 
     The pouring and use of concrete is a fundamental construction task in the trade. It is referred to as the placement of concrete. It is often required in the installation of sidewalks. It is placed over steel decks to provide the flooring base for multi-story skyscrapers; it is placed for the flooring of large warehouse or industrial structures; and it is placed to form the basis for water retention basins and reservoirs. It further provides the basis for highway surfaces and airport runways. 
     There are two essential joints associated with concrete slabs. The first joint is commonly referred to as the expansion joint and passes completely through the concrete slab. The expansion joint is designed to allow for the expansion and contraction of the concrete slab in response to ambient temperature conditions. The second joint is commonly referred to as the control joint. The control joint is a linear impression formed in the concrete slab after its placement. It does not extend through the concrete slab. The purpose of the control joint is to control the direction of any cracking which may appear in the slab over time. Typical control joints would run transversely on the slab from one edge to the other. Control joints would normally be formed by dragging a trowel across the poured concrete while it was still wet to form the linear impression, and in some instances, diamond saws would be used to form the control joints after the concrete slab had hardened. 
     In the prior art, any handy material would be utilized to form the peripheral outline or frame of the concrete slab and any associated expansion joints. The concrete would be placed within the frame and leveled using a screed or squeegee-like rake, which would be dragged across the surface of the wet concrete while resting on at least two adjacent or abutting framing members in order to achieve a planar level slab. The framing members upon which the screed rested while leveling the surface of the concrete slab are referred to in the trade as screed guides, and the screed guide and its mount are commonly referred to as screed guide/control joints. 
     European building codes require a ten year guarantee with respect to poured concrete slabs. No such guarantee is yet required or exists in US building codes. This dichotomy has led to greater technical advances in Europe with respect to the pouring of concrete slabs. In particular, a screed guide profile has been developed in which the screed guide itself also forms the control joint for the concrete slab. The use of these combination screed guide/control joints presents some great advantages in the area of placement of concrete slabs and in the life expectancy of the concrete slabs. However, the accurate placement of the screed guide/control joints sometimes proved laborious and time consuming, and do not address all of the problems associated therewith. 
     Initially, some screed guide/control joints were positioned by pouring small mounds of concrete in a desired linear direction before positioning of the screed guide/control joint. The screed guide/control joint would then be positioned on the small mounds of concrete to the desired height, and the mounds of concrete would be allowed to set. Once the mounds of concrete had set, securing the screed guide/control joint, the concrete slab would be poured to the height of the upper edge of the screed guide/control joint. This method became laborious and time consuming since normally 24 hours would have to elapse from the time that the mounds of concrete were poured until the time that the slab could be poured to allow for the mounds to set and position the screed guide/control joint. 
     The method of installing screed guide/control joints evolved to the use of rebar stakes, and clips. The section of rebar would be pounded into the ground to an estimated height, each rebar being positioned approximately two feet apart. Clips would then be installed on the top of the rebar, the upper portion of such clips presenting a dove tail channel into which a preformed plastic screed guide/control joints having a pyramidal cross section would snap fit. The worker would hand adjust the depth of the rebar in order that the clips were at the same height so that the screed guide/control joint presented a level upper edge for placement of the concrete slab. This method presents problems when a vapor barrier is utilized, since the rebar stakes will pierce the plastic sheets or other types of vapor barriers and degrade their performance. It also presents a problem when concrete flooring is being placed on a steel deck as is done in the construction of multi-story buildings or skyscrapers. The rebar stake cannot be driven into or through the steel deck. 
     An additional problem is presented in those instances where concrete slabs are being placed onto compacted gravel subgrade or ground. Some installations call for void forms to be placed beneath the concrete slab at various locations to compensate for the expansion and contraction of the ground due to expansion and contracting soil conditions. These voided areas are formed utilizing cardboard housings which are positioned prior to the placement of the concrete slab, the slab being placed essentially over the cardboard encapsulating the cardboard housing between the concrete and the ground. The void area under the cardboard housing and in contact with the ground provides compensation for expansion and contraction of the ground. The cardboard housing over time will eventually deteriorate, but the void will remain. The use of the rebar stakes or any stake on such a slab would pierce the cardboard housing and obviate its desired purpose of forming a void between the poured concrete and the ground. 
     An additional problem associated with the current installation of screed guide/control joints is that the profile of the screed guide/control joint varies depending on the thickness of the concrete slab. Two sizes of screed guide/control joint profiles are currently used for screed guide/control joint placement in various thicknesses of concrete slabs. A large profile screed guide/control joint is utilized for placement of six inches or greater, and a small profile screed guide/control joint is used for placements of lesser thickness. Since the size of the screed guide/control joints vary, the installer must inventory a quantity of clips that will fit the two profiles. 
     U.S. Pat. No. 8,925,259 to Reed addressed the aforesaid problems and set forth a system which overcomes the problems and disadvantages of the prior art in allowing for the accurate placement and adjustment of screed guide control joints and the elimination of multiple sizes. Applicant in this application has improved the screed guide control joint profile to further improve the pouring of concrete slabs, and to extend their life expectancy. 
     OBJECTS OF THE INVENTION 
     An object of the present invention is to provide an improved screed guide/control joint and clip to accelerate and facilitate the accurate placement of the screed guides of various sizes to accommodate concrete slabs of various thickness. 
     A further object of the present invention is to provide for an improved screed guide/control joint and clip which allows for the facile and exact adjustment of the height of the screed guide/control joint. 
     A still further object of the present invention is to provide for an improved screed guide/control joint and clip, the profile of which will provide better adherence to the surrounding poured concrete and improve lateral flexibility with the expansion and contraction of the concrete. 
     A still further object of the present invention is to provide for an improved screed guide/control joint and clip having a profile which will act as a water stop function to impede the growth of weeds or other plant growth in the control joints. 
     A still further object of the present invention is to provide for an improved screed guide/control joint and clip in which the upper interior cell of the profile is formed with protruding frictionalized tabs designed to frictionally engage different sized steel rods or rebar used to butt join, abutting ends of screed guide/control joint joints. 
     A still further object of the present invention is to provide for an improved screed guide/control joint and clip having a large empty lower cell of the profile which can be used as a conduit for electrical or fluid conduits. 
     SUMMARY OF THE INVENTION 
     An improved screed guide/control joint and clip for the placement of concrete in concrete slabs on a plurality of different surfaces, the clip accommodating different sized screed guides to accommodate different depths of concrete pours, the screed guide/control joint inhibiting water passage, impeding growth of weeds in the joint, and having improved lateral flexibility to the expansion and contraction of the concrete, the screed guide also allowing placement of conduits within the cover portion of the channel cavity of the screed guide. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects of the present invention will become apparent, particularly when taken in light of the following illustrations wherein: 
         FIG. 1  is a perspective view of a typical screed guide/control joint of the prior art; 
         FIG. 2  is a perspective view of the screed guide/control joint of  FIG. 1  illustrating a prior art method of installation; 
         FIG. 3  is an exploded perspective view of the screed guide/control joint of  FIG. 1  and a second prior art method of installation; 
         FIG. 4  is an end profile view of the improved screed guide/control joint of the present invention; 
         FIG. 5  is an exploded end view of the improved screed guide/control joint of the present invention with mounting clip and removable elevating cap; 
         FIG. 6  is a perspective view of the improved screed guide/control joint of the present invention secured to a mounting clip and showing the elevating cap snapped into place; 
         FIG. 7  is an end profile view of a small profile improved screed guide/control joint for use with shallower concrete pours; 
         FIG. 8  is an exploded end view of the smaller profile improved screed guide/control joint of  FIG. 7 ; and 
         FIG. 9  is a perspective exploded view of the smaller profile screed guide/control joint illustrating details of the mounting clip of  FIGS. 4-8 . 
         FIG. 10  is a perspective exploded view of an exteriorly threaded tubular cap member; and 
         FIG. 11  is a bottom view of the tubular cap member of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a screed guide of the prior art used to form a screed guide/control joint. The screed guide  10  is linear in shape generally coming in 12 to 16 foot lengths to be cut in the field to the desired length required. It is formed of extruded polymer and has a base portion  12  comprised of a planar bottom wall  14 , two opposing side walls  16  and  18 , angled upper walls  20  and  22  terminating in an upwardly extending tower portion  24 , triangular in cross section formed by two angled side walls  26  and  28  and terminating in an apex which forms the upper edge  30  of screed guide  10 . The interior of the base and tower portions are formed during the extrusion process with cross member ribs  34  for support. Additionally, the angled side walls  26  and  28  of tower portion  24  may also be formed with longitudinal parallel ribs  36  to aid in the setting process when screed guide  10  is encapsulated in concrete. 
     In most instances, the bottom wall  14  of the base member is slightly flared downwardly at its side walls  16  and  18  defining rigid enclosed longitudinal channels to aid in its snap fitting with a screed guide/control joint clip as described hereafter. 
     It should be noted that screed guides generally are formed in two sizes, large profile and small profile. The small profile screed guide is used to form screed guide/control joints in concrete slabs up to six inches in depth, and a large profile screed guide is used for slabs in excess of six inches in depth. A typical large profile screed guide would have a base portion with slightly over two inches wide and a tower portion height of approximately three to three and a half inches, whereas the small profile screed guide dimensions would be approximately half those of the large profile screed guide. 
       FIG. 2  is a perspective view of screed guide  10  of  FIG. 1  illustrating its setting with respect to a prior art method of installation to form a screed guide/control joint. In this method of installation, small mounds of concrete  50  are poured in a linear orientation approximately two feet apart so that the base portion  12  of the screed guide may be set on these concrete mounds and the mounds allowed to harden and secure the screed guide/control joint. Once set, the concrete slab would be placed, encapsulating the entire length of the screed guide/control joint to the height of its upper edge  30 . Depending upon the area of concrete to be placed, a plurality of screed guide/control joints would be set in this manner, the desired distance apart in accordance with code, in order to define the area of concrete to be placed. This method of setting the screed guide/control joint is very time consuming, laborious, and requires exacting measurements to ensure that upper edge  30  is at a consistent height along the length of the screed guide/control joint and on all similarly situated screed guide/control joints. 
     The desire is to obtain a concrete slab of some dimension which has a uniform planar upper surface. To that end, the initial concrete mounds  50  that are placed must be of the desired height and the screed guide must be set at the accurate height, as well as all parallel and abutting screed guide/control joints to insure that the upper edge  30  of all of the screed guide/control joints utilized to define the concrete slab are at the same height. This can best be described as a hit or miss method of obtaining a uniform planar concrete slab. 
       FIG. 3  is an exploded perspective view of the screed guide of  FIG. 1  and an alternative method for installation developed in the prior art. In this configuration a plurality of lengths of rebar  60  are driven into the underlying substrate  62  to a desired height  64 . The rebar is installed in a linear orientation approximately two feet apart. A screed guide/control joint clip  66  is then frictionally positioned on the upper extended end  68  of the rebar  60 . The screed guide/control joint clip  66  comprises a tubular base  70  which slidably engages the upper end  68  of the rebar  60 . Unitarily formed to the upper end of tubular base  70  is a single dove tail channel  72 . Dove tail channel  72  is dimensioned to the width of the base portion  12  of screed guide  10 . 
     The installer would adjust the height of the sections of rebar  60  by hand to insure that the screed guide/control joint clips  66  were all at the same height. The screed guide would then be snap fit into the dove tail channel  72  of the screed guide/control joint clip, thus securing the screed guide/control joint at a desired height above the substrate  62 . The installer would take measurements to insure that the upper edge  30  of all screed guides  10  utilized and placed in order to place the concrete slab were all at the same height. The concrete would then be poured encapsulating the rebar  60 , the screed guide/control joint clip  66  and the screed guide/control joint  10  to the height of its upper edge  30 . Sections of the concrete slab would be poured in succession between each screed guide/control joint so positioned. 
     This method, while an improvement over the use of small poured concrete mounds, still required checking by the installer to insure that the upper edges  30  of all of the screed guide/control joints  10  were at the same level, and required multiple adjustments of the height of the rebar, since the screed guide/control joint would not snap fit and lock into the dove tail channel  72  of the screed guide/control joint clip  66  unless all screed guide/control joint clips  66  were at the same height. 
     Applicant&#39;s improved screed guide/control joint is intended to be utilized with the mounting method as set forth in U.S. Pat. No. 8,925,259, and the aforesaid patent&#39;s teachings are incorporated by reference as if set forth at length and in detail. Applicant&#39;s improved screed guide/control joint provides advantages as set forth in the objects of the invention. Its improved design as well as the clip design allows a clip to accommodate a screed guide of either large or small size eliminating multiple inventory. It further provides for use of an interlocking elevated cap or extension profile for use with stamped concrete and exposed aggregate applications. 
       FIG. 4  is an end view of a large profile screed guide/control joint of the present invention. The large profile screed guide/control joint  100  is a linear shape normally extending anywhere from 12 to 16 feet and is extruded polymer. It normally is cut to desired lengths in the field, or it is abutted against identical screed guide/control joints  100  to provide for an extended linear screed guide/control joint for the pouring of concrete. 
     The screed guide/control joint  100  is generally pyramidal or triangular in cross section, and has an irregularly shaped base member  102  having a central arcuate member  104 , with unitary S-shaped side walls  106  and  108  which extend outwardly and curve downwardly terminating in an inwardly extending flange  110  and  112  positioned in the same plane as the central arcuate member  104 &#39;s lowest point and defining two parallel longitudinal open channels  114  and  116 . The open channels permit flexibility of base member  102  for ease of fit to a mounting clip. 
     Two upstanding angular walls  118  and  120  extend upwardly from the base member  102 , the angled upstanding vertical walls are joined at an apex  122  forming a generally triangular shaped longitudinal cavity  124 , the apex  122  joinder of the two upstanding angled side walls  118  and  120  extending further with vertical member  126  from the apex  122 . 
     As best illustrated in  FIG. 5 , which is an exploded perspective view of the screed guide/control joint  100  of the present invention, there is a snap fit removable, longitudinal cap member  130  which can be fitted over the vertical joinder extension member  126  of the angled side walls  118  and  120  providing a removable height extension.  FIG. 5  also illustrates a clip member  132 , utilized in adjusting the height of the screed guide/control joints  100  depending upon the thickness of the slab of concrete which is to be laid. The clip  132  has an improved mounting surface  133  over that which is described in U.S. Pat. No. 8,925,259. 
     The triangular cavity portion  124  formed by the angular vertical side walls  118  and  120  and the base member  102 , is bifurcated by a substantially horizontal wall  134  running the longitudinal length of the screed guide/control joint  100 , the substantially horizontal bifurcation wall  134  dividing the cavity  124  into an upper chamber  136  and a lower chamber  140 . The upper chamber  136  is further formed with a plurality of inwardly depending longitudinal flanges or tabs  142 . These flanges or tabs  142  are designed to stabilize different diameter sized steel rods or rebar commonly used in the laying of concrete. Sections of these steel rods or rebar are frequently used to abut adjoining screed guide/control joints  100 . A portion of a steel rod or rebar is inserted into the upper cavity  136  at one end of the screed guide/control joint  100  and is frictionally engaged and maintained by the inwardly depending flanges or tabs  142 . An opposing end of the rebar would be slidably frictionally inserted into an abutting screed guide/control joint  100 , so that the screed guide/control joint ends could be pushed together and held in abutting relationship. The lower cavity  140  of screed guide/control joint  100  can be utilized as a cavity for the running of conduit, be it electrical, or in some cases a fluid conduit when it is desired to have a heated slab of concrete. 
     Formed on the exterior surface of the angled upstanding vertical side walls  118  and  120 , are a pair of outwardly extending winglets or tabs  144 . The lower pair of winglets and tabs as illustrated in  FIGS. 4 and 5 , extend outwardly and are angled slightly upwardly, whereas the upper winglets or tabs  144  are extended outwardly and downwardly. The exterior winglets  144  are designed to provide better adherence to the surrounding concrete when poured, and to improve the lateral flexibility of the screed guide/control joint  100  during the expansion and contraction process undergone by concrete slabs. They also provide to some extent a water stop function which would impede the growth of flora, such as weeds, from growing and maturing within the control joints. 
     The removable snap fit cap  130  which can be slidably inserted over the vertical portion  126  of the screed guide/control joint  100  extending upwardly from the apex  122  of the vertical angled side walls  118  and  120 , serves two purposes. 
     The removable cap  130  is initially placed on the screed guide/control joint during the pouring process and is removed immediately thereafter which provides for a recessed control joint below the level of the concrete and which is nearly invisible and provides for a more aesthetic surface of the poured concrete. When removably secured, it allows mats which are used for stamping designs into the concrete to lay flat over the just placed concrete for such stamping. 
       FIG. 6  is a perspective view of the large profile screed guide/control joint  100  of the present invention illustrated in a snap fit relationship with an improved clip  132  and mounting surface  133 . The unique design of the base member  102  of the large profile screed guide/control joint  100  allows for it to be snap fit onto the mounting surface  133  of improved support clip  132  and maintained in the position during the pouring process. 
       FIG. 7  is an end profile of a smaller size improved screed guide/control joint  100 A for use with shallower concrete pours. The screed guide/control joint  100 A in the low profile is again linear in shape normally extending anywhere from 12 to 16 feet, and is formulated from extruded polymer. The screed guide control joint  100 A is of a general pyramidal or triangular cross section having a base member  102 A having a central arcuate base member  104 A. Unlike the large profile screed guide/control joint  100 , the small profile has no extending flanges which form open channels  114  and  116 . The arcuate central base member  104 A of the base member  102 A transitions to a closed flange having an upward slope  106 A and  108 A, which in turn transitions into upstanding angular walls  118 A and  120 A extending upwardly and being joined at an apex  122 A forming a generally triangular shaped longitudinal cavity  124 A. The angled walls  118 A and  120 A merge at an apex and extend further vertically  126 A from the apex  122 A. 
     Removably secured to vertical member  126 A of small profile screed guide/control joint  100 A is a snap fit, removable, longitudinal cap member  130 A similar to the identical cap member associated with the large profile screed guide/control joint. 
     Formed on the exterior surface of the angled upstanding side walls  118 A and  120 A are a plurality of outwardly extending winglets or tabs  144 A which extend longitudinally with the screed guide/control joint  100 A. These exterior winglets  144 A serve the same purpose as those winglets described in reference to the large profile screed guide control joint  100 . 
       FIG. 8  is an exploded end view of the small version screed guide/control joint  100 A on the improved mounting clip  132 . The small profile screed guide/control joint  100 A utilizes only the central channel of the support portion of the improved mounting clip  132  for positioning and stabilizing the screed guide/control joint  100 A and for adjustment of height. The outer channels of the improved mounting clip  132  are not utilized for mounting the small profile screed guide/control joint  100 A, but only the large profile screed guide/control joint  100 . 
       FIG. 9  is a perspective view of the screed guide/control joint of  FIG. 8 . The mounting clip  132  is the same as illustrated in  FIGS. 5, 6, 7, and 8 , and illustrates the structure of mounting surface  133 . The improvement of the clip  132  deals with the mounting surface  133  atop the tubular portion of mounting clip  132 . The mounting portion  133  is substantially planar having four upstanding parallel wall or ridge members, outer wall members  180  and  182 , and inner wall members  184  and  186 . The interior wall members  184  and  186  are slightly higher than the end wall members  180  and  182 , and the interior walls are capped with longitudinal inwardly extending flange members  194 . The four upstanding walls define three channels, central channel  188 , and side channels  190  and  192 . With reference back to  FIGS. 6 and 7 , the improved mounting clip  132  serves to snap fit engage the main body base member portion  104  of the large profile screed guide/control joint  100  in central channel  188  with the internal flanges  194  on interior walls  184  and  186  forming a snap fit arrangement with the lower profile of the large screed guide/control joint  100 , and the flange portions of the large profile of the screed guide/control joint  100  are fitted into the side channels  190  and  192  of the mounting surface  133  of the clip  132 . 
     The improved support clip  132  provides a facile means of adjusting the height of the screed guide/control joint  100  in the manner explained in the &#39;239 patent and insuring that the height chosen is consistent and uniform throughout the longitudinal length or run of the screed guide/control joint  100  and/or abutting screed guide/control clips  100 . 
       FIG. 9  illustrates the small profile screed guide/control joint  100 A engaged with the improved clip  132  wherein the lower portion  104 A of the small profile screed guide/control joint  100 A engages solely with the central channel  188 . This structure allows for a single clip  132  to accommodate both the large profile and the small profile screed guide/control joints, and eliminates the need to carry excess inventory with respect to clips to accommodate both. It further simplifies the clip design. 
     Therefore, while the present invention has been disclosed with respect to the preferred embodiments thereof, it will be recognized by those of ordinary skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore manifestly intended that the invention be limited only by the claims and the equivalence thereof.