Abstract:
An adjustable, universal screed guide/control joint clip for positioning screed guide/control joints utilized in the placement of concrete in concrete slabs, the adjustable universal screed guide clip allowing for the exact adjustment of the height of the screed guide attached thereto for the placement of the concrete slabs, the adjustable universal screed guide clip allowing the installation of the screed guide in applications heretofore not allowable, the adjustable, universal screed guide/control joint clip capable of accommodating both large and small profile screed guides.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an adjustable, universal screed guide/control joint clip used in the positioning of screed guide/control joints, which in turn are utilized in the placement of concrete in concrete slabs, the screed guides provide precise placement of the concrete in concrete slabs, the adjustable, universal screed guide clip allowing for exact adjustment of the height of the screed guide, as well as allowing the installation of the screed guide in applications heretofore denied. 
     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 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. 
     European building codes require a ten year guarantee with respect to poured concrete slabs. No such guarantee is 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. 
     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. 
     It presents an additional problem 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. 
     This screed guide profile and the advantages thereof would find greater acceptance both in Europe and the US if the aforesaid disadvantages could be overcome. Applicant&#39;s system addresses and overcomes each disadvantage. 
     OBJECTS OF THE INVENTION 
     An object of the present invention is to provide a novel screed guide/control joint clip system to accelerate and facilitate the accurate placement of the screed guides and limit the use of different sizes of clips. 
     A further object of the present invention is to provide for a novel screed guide/control joint clip system which allows for the facile and exact adjustment of the height of the screed guide/control joint clip and the screed guide/control joint. 
     A still further object of the present invention is to provide for a novel screed guide/control joint clip system which permits the use of the system on substrates which heretofore would not accept the system. 
     A still further object of the present invention is to provide for a novel screed guide/control joint clip system which incorporates a base member securable to a substrate of the type which did not previously permit the usage of a screed guide/control joint. 
     SUMMARY OF THE INVENTION 
     An adjustable, universal screed guide/control joint clip for positioning screed guide/control joints utilized in the placement of concrete in concrete slabs, the adjustable universal screed guide clip allowing for the exact adjustment of the height of the screed guide attached thereto for the placement of the concrete slabs, the adjustable universal screed guide clip allowing the installation of the screed guide in applications heretofore not allowable, the adjustable, universal screed guide/control joint clip capable of accommodating both large and small profile screed guides. 
    
    
     
       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 screed guide/control joint utilized with the present invention; 
         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 a top view of the screed guide/control joint clip of the present invention; 
         FIG. 5  is an end view of the screed guide/control joint clip of the present invention; 
         FIG. 6  is a side view of the screed guide/control joint clip of the present invention; 
         FIG. 7  is a perspective view of the threaded cap rebar engaging member; 
         FIG. 8  is a cross sectional view of the screed guide/control joint clip and threaded cap rebar engaging member along Plane  8 - 8  of  FIG. 4 ; 
         FIG. 9  is an end view of the screed guide/control joint clip of the present invention in orientation for receipt of a low profile screed guide/control joint; 
         FIGS. 10A and 10B  are bottom views of the threaded cap rebar engaging member illustrating two embodiments of the orientation of internal ribbing to accommodate various diameter rebar; 
         FIG. 11  is a top view of a base member allowing use of the screed guide/control joint clip system on vapor barriers, steel substrate and void forms; 
         FIG. 12  is a side view of the system installed on a steel substrate; 
         FIG. 13  is a top view of a second embodiment of a screed guide/control joint clip of the present invention; and 
         FIG. 14  is an end view of the second embodiment of the screed guide/control joint clip illustrated in  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a screed guide/control joint utilized in the present invention. The screed guide/control joint  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 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/control joint  10 . The interior  32  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/control joint  10  is encapsulated in concrete. 
     In most instances, the bottom wall  14  of the base member is not planar, but rather, slightly flared downwardly at its side walls  16  and  18  to aid in its snap fitting with a screed guide/control joint clip as described hereafter. 
     It should also be noted that  FIG. 1  illustrates the general shape of the screed guide/control joint used with the present invention, however, minor variations, particularly with the longitudinal ribs on the exterior of the tower, may vary from manufacturer to manufacturer. It should also be pointed out that screed guide/control joints generally are formed in two sizes, large profile and small profile. The small profile screed guide/control joints are used with concrete slabs up to six inches in depth, and the large profile screed guide/control joints are used for slabs in excess of six inches in depth. The large profile and small profile screed guide/control joints are similar in all aspects except their dimensions. A typical large profile screed guide/control joint would have a base portion with slightly over two inches and a tower portion height of approximately three to three and a half inches, whereas the small profile screed guide/control joint dimensions would be approximately half those of the large profile screed guide. 
       FIG. 2  is a perspective view of screed guide/control joint  10  of  FIG. 1  illustrating its setting with respect to a prior art method of installation. 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/control joint 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/control joint 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/control joint 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 dove tail channel  72 . Dove tail channel  72  is dimensioned to the width of the base portion  12  of screed guide/control joint  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/control joint 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 guide/control joints  10  utilized and placed in order to place the concrete slab were all at the same height. The concrete would then be placed 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 placed 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 screed guide/control joint clip provides several advantages over the prior art. First, it can accommodate both large profile and small profile screed guide/control joints in one clip assembly. Secondly, its construction allows for a firm grip on both European rebar which measures approximate 12 mm in diameter, and US rebar, which is slightly larger at 12.57 mm. Thirdly, the interior member which is exteriorly threaded easily allows for the accurate height adjustment of the screed guide/control joint clip to insure that the upper edges of all screed guide/control joints are level when installed on the screed guide/control joint clip. Lastly, the incorporation of a base support member cooperable with the rebar, allows for the use of screed guide/control joints where vapor barriers and liners are initially installed over the substrate, allows for the use of Applicant&#39;s screed guide/control joint clip in conjunction with screed guide/control joints on steel substrate for multi-story skyscrapers, and allows for the use of screed guide/control joints on void forms. All of these areas were previously denied the use of screed guide/control joints because of the required installation methods previously discussed. 
       FIG. 4  is a top view of the screed guide/control joint clip of the present invention,  FIG. 5  is an end view of the screed guide/control joint clip of the present invention, and  FIG. 6  is an opposing end view of the screed guide/control joint clip. The screed guide/control joint clip  80  cooperates with a threaded cap rebar engaging member  82  illustrated in  FIG. 7 , which will be more fully discussed hereafter. Screed guide/control joint clip  80  comprises a tubular member  84  having an internal bore  86 , internal bore  86  having a single threaded member  88  cooperable with threaded cap rebar engaging member  82  as more fully discussed with respect to  FIG. 8  hereafter. Unitarily formed with tubular member  84  is a first dove tail channel member  88  having a base portion  90  and two opposing upstanding side walls or prongs  92  and  94 , upstanding side walls or prongs  92  and  94  being slightly inwardly protruding at their upper terminus  96  and  98  to define a channel  100  for engagement with the base member  12  of a large profile screed guide/control joint  10  snap fit there between. 
     A second inverted dove tail channel member  102  is unitarily hingeably secured  106  to an open edge  104  of first dove tail channel member  88 . Second, inverted dove tail channel member  102  in the configuration illustrated in  FIGS. 4 ,  5 , and  6  has a base member  108 , and depending outer side walls or prongs  110  and  112 . Second inverted dove tail channel member  102  also has the two inner side walls or prongs  114  and  116  spaced apart from outer side walls or prongs  110  and  112  depending downwardly and terminating with a nubbed apex similar to the side walls of first dove tail channel member  88 . The distance between the downwardly depending inner side walls or prongs  114  and  116  corresponds to the width of the base of a small profile screed guide/control joint. 
     Referring to  FIG. 9 , which is an end view of the screed guide/control joint clip of  FIGS. 4 ,  5 , and  6  with the second dove tail channel member  102  in hinged relationship with the first dove tail channel member  88 . The flexible hinge  106  allows for second dove tail channel member  102  to be rotated  180  degrees such that its outer side walls or prongs  110  and  112  frictionally lock in a snap fit manner with the side walls or prongs  92  and  94  of first dove tail channel member  88 . This positions the inner side walls or prongs  114  and  116  of second dove tail channel member  102  in a central upwardly extending position converting the screed guide/control joint clip  80  from one accommodating a large profile screed guide/control joint to one which can now accommodate a low profile screed guide/control joint, thus the elimination of two separate sized clips for the installation and pouring of concrete. 
     It will be noted that the base members  90  and  108  of first and second dove tail channel members  88  and  102  are not planar, but are slightly arcuate to accommodate the contour of the base member  12  of either a large profile or small profile screed guide/control joint. Additionally, the base members  90  and  108  of first and second dove tail channel members  88  and  102  may also be formed with apertures  120  and  122  to aid in the molding process. 
       FIG. 7  is a perspective view of threaded cap rebar engaging member  82 .  FIGS. 10A and 10B  are bottom views of two embodiments of threaded cap rebar engaging member  82 . Threaded cap rebar engaging member  82  is tubular having an exterior threaded surface  130  and an interior surface  132  having a plurality of radial or non-radial ribs  134  protruding inwardly from inner surface  132 . The ribs  134 , being non-radial in orientation with respect to tubular threaded cap rebar engaging member  82  allows for threaded cap rebar engaging member  82  to be utilized with respect to both European and United States rebar dimensions, thus allowing for threaded cap rebar engaging member to be snap fittingly engaged over an end of either type of rebar. Radial ribs may also be used but sized accordingly for the size of rebar utilized. 
       FIG. 8  is a cross sectional view of the screed guide/control joint clip and threaded cap rebar engaging member along Plane  8 - 8  of  FIG. 4 . Screed guide/control joint clip  80  has a single internal thread  88  cooperable with the external threading  130  on threaded cap rebar engaging member  82  to allow for the height adjustment of the screed guide/control joint clip  80  once the threaded cap rebar engaging member  82  has been snap fit over an end of rebar. This allows screed guide/control joint clip  80  to be accurately rotated on threaded cap rebar engaging member  82  to achieve the desired height. 
     The screed guide/control joint clip system described thus far eliminates the need for concrete mounds to be poured and measurements to be taken with respect to the placement of screed guides on such concrete mounds. It also eliminates the eyeball measurements and adjustment of the depth of rebar in the substrate in order to achieve equality in screed guide levels. The addition of a base member to a system previously described, also allows for the use of the system in those instances where a liner or vapor barrier is required over the substrate or where the substrate is steel, and also where conditions require that void forms be provided in the concrete slab for the underlying expansion and contraction of the substrate. 
       FIG. 11  is a top view of a base support member  140  designed to be utilized with the screed guide/control joint system, and  FIG. 12  is a side view of the base member with the screed guide/control joint clip system installed on a steel substrate. The base member  140  comprises a planar base  142  of any particular geometric shape, but illustrated as being circular in  FIGS. 11 and 12 . Centrally positioned on planar base  142  and unitary therewith is upstanding tubular member  144  having an outer side wall  146  and an inner side wall  148  there being a plurality of radial or non-radial rib members  152  extending inwardly from the inner side wall  148 . Positioned about the planar base  142  would be a plurality of apertures  150  extending through planar base  142 . Additionally there may be a central aperture  153  through planar base  142  positioned within tubular member  144 . 
     In this configuration, an appropriate adhesive  156  would be applied to either the substrate  158  or the undersurface  160  of planar base  142  and base member  140  would then be positioned on the substrate  158 . The application of the adhesive  156  would be such that it would adhere the under surface  160  of base member  142  and to the substrate, but would also pass through or ooze through the various apertures  150  and  153  in the planar base so as to extend to the upper surface of planar base  142  thus insuring firm adhesion of base member  140  to the substrate  158 , be it steel, vapor barrier, or cardboard void forms. 
     An appropriate length of rebar  60  would then be engaged in tubular member  144  and rigidly maintained by the rib members  152  extending therein. The installer would secure base members  140  in this fashion at the required distances on the substrate. The installer would then snap fit a threaded cap rebar engaging member  82  onto each piece of rebar  60 , and threadedly secure and adjust screed guide/control joint clip  80  to the threaded cap rebar engaging member  82  such that the heights of the base members  90  or  108  of the dove tail channel members  88  or  102  would be equal. Screed guide/control joints would then be snap fit and installed to the screed guide/control joint clips  80  and concrete would be placed encapsulating the base member  140 , the rebar  60 , the rebar engaging member  82 , the screed guide/control joint clip  80 , and the screed guide/control joint  10 . 
       FIG. 13  is a top view of a screed guide/control joint clip  80 B similar to the screed guide/control joint clip  80  illustrated in  FIG. 4 , and  FIG. 14  is an end view of screed guide/control joint  80 B from end. Screed guide/control joint clip  80 B has a similar tubular member  84 , having an internal bore  86 , internal bore  86  having a single threaded member  88  cooperable with the threaded cap rebar engaging member  82  as discussed with respect to  FIG. 8 . Screed guide/control joint clip  80 B also has an identical first dovetail channel member  88 . 
     A second dovetail channel member  102 B is unitarily secured to open edge  104 B of first dovetail channel member  88  by means of a flexible hinge arm  106 B. Second dovetail channel  102 B is identical to the second dovetail channel member  102  as illustrated in  FIG. 4  with the exception that it is not inverted. Flexible hinge arm  106 B is of sufficient length to allow second dovetail channel member  102 B to be twisted or turned  180  degrees in a plane allowing for outer side walls or prongs  110 B and  112 B to be snap fit or inserted into first dovetail channel member  88  such that the two inner side walls or prongs  114 B and  116 B are in position for receipt of a small profile screed guide. Flexible arm  106 B eliminates the hinge  106  illustrated in  FIG. 4  and presents an alternative manner for the production of the screed guide control joint clip. 
     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.