Abstract:
A connector system for mechanically connecting two structural elements to each other, consisting of a connector element and mating grooves in each structural element. The connector element is comprised of a base plate having a split-tongue element at each side or end of said base plate. Each joined element has a mating groove formed into its connector-receiving surface. The mating groove is designed to allow fabrication via four sequential circular saw cuts, without loss of saleable decorative surface, and at a rate consistent with economical commercial production of vinyl, laminate, or hardwood flooring. The connector element is readily extruded in a variety of polymers, including PVC. The connector and mating grooves interact so as to generate a force component acting to forcibly draw the connector into the mating grooves. The connector system operation is relatively insensitive to geometric deviations associated with normal manufacturing methods.

Description:
BACKGROUND OF INVENTION 
     Field of Invention 
       [0001]    This invention is a CIP application that claims priority to U.S. Pat. No. 9,322,421 filed on Mar. 9, 2015. This invention relates to a connector system for mechanically joining building panels (such as vinyl, laminate, or hardwood flooring); mechanically attaching decorative items (such as wall panels, ceiling panels, or automotive trim); mechanically attaching subsystems (such as automotive dashboards; or mechanically connecting elements of ready-to-assemble furniture. 
       Prior Art 
       [0002]    The connector system describe in U.S. Pat. No. 9,322,421, herein referred to as the “prior patent”, is treated as prior art and provides the basis for the present inventive connector modifications.  FIGS. 1 to 4  describe this prior art and restate the terminology that is used in that patent and that is carried over to the present continuation-in-part application. 
         [0003]      FIG. 1  shows the normal embodiment of the connector system as taught in the prior patent and as used to connect hardwood flooring. The upper detail shows the connector system prior to assembly, and the lower detail shows the assembled system wherein the two floor board elements are mechanically joined by the connector. The arrows  119  and  120  in the upper figure show the direction in which the joined elements move relative to the connector during assembly. The descriptor “normal” in this embodiment indicates that the motion of the connector relative the floor boards is normal to the flat upper surfaces of the boards. 
         [0004]    In  FIG. 1 , items  1  and  3  a first and second floor board respectively, and items  2  and  4  are their respective decorative surfaces. Item  31  is a normal connector element having a first split-tongue  33  and second split-tongue  36 . The two split-tongues  33  and  36  are supported by base plate  32 . Said base plate  32  has a first extension  55  and a second extension  56 . The first split-tongue  33  has two flexible arms  34  and  35  respectively, and the second split-tongue  36  has two flexible arms  37  and  38  respectively. The flexible arms  34 ,  35 ,  37 , and  38  have outward facing nubs  98 ,  99 ,  100 , and  101  respectively at their distal ends. The first split-tongue  33  mates with the mating groove  39  in the first floor board  1 , and the second split-tongue  36  mates with the mating groove  40  in the second floor board  3 . 
         [0005]    In  FIG. 1 , the first base plate extensions  55  is received by inner recess region  118  as the first floor board  1  is moved in the direction of first assembly arrow  120  during connector system assembly. Similarly, the second base plate extensions  56  is received by inner recess region  48  as the second floor board  2  is moved in the direction of second assembly arrow  119  during connector system assembly. .In  FIG. 1 , the base plate  32  provides vertical support for those portions  108  and  109  that overhang the normal connector. 
         [0006]      FIG. 2  shows the lateral embodiment of the connector system as taught in the prior patent and as used to connect hardwood flooring. The upper detail shows the connector system prior to assembly, and the lower detail shows the assembled system wherein the two floor board elements are mechanically joined by the connector. The arrows  115  and  116  in the upper figure show the direction in which the joined elements move relative to the connector during assembly. The descriptor “lateral” in this embodiment indicates that the assembly motion is in a lateral direction, i.e., parallel to the flat upper surfaces of the floor boards and normal to the joined faces. 
         [0007]    In  FIG. 2 , items  1  and  3  are first and second floor boards respectively, and items  2  and  4  are their respective decorative surfaces. Item  17  is a lateral connector element having one split-tongue element  18  and a second split-tongue element  19 . The two split-tongues  18  and  19  are formed on either side of base plate  20 . Split-tongue  18  has two flexible arms  21  and  22 , and split-tongue  19  has two flexible arms  23  and  24 . The flexible arms  21 ,  22 ,  23 , and  24  have outward facing nubs  41 ,  42 ,  43 , and  44  respectively at their distal ends. Split-tongue  18  mates with groove  25  in floor board  1  and split-tongue  19  mates with groove  26  in floor board  3 . Said nubs  41  and  42  contact the side-walls of said mating groove  25  of said split-tongue  18 ; and said nubs  43  and  44  contact the side-walls of the said mating groove  26  of said split-tongue  19 . 
         [0008]    In  FIG. 2 , the first and second sides of upper base plate extension  45  are received by recess regions  113  and  59  as the first and second floor boards  1  and  2  are moved in the direction of the arrows  115  and  116  during connector system assembly. Similarly, the first and second sides of lower base plate extension  46  are received by recess regions  114  and  60  as the first and second floor boards  1  and  2  are moved in the direction of the arrows  115  and  116  during connector system assembly. The base plate extensions  45  and  46  of base plate  20  provide vertical structural support to floor board portions  28  and  29  that overhang the connector in  FIG. 2 . The mating groove design for the normal connector, item  31  in  FIG. 1 , is shown in  FIG. 3 . The groove is fabricated into the connector-receiving surface opposite the decorated surface  4  of second floor board  3 . The groove consists of five regions arranged sequentially in the direction  30  of tongue insertion into the groove. The first region is a recess region defined by recess upper surfaces  47  and  48 . The upper surface  47  of the recess region receives the normal connector base plate  32  and upper surface  48  is receives the base plate extension  56  in  FIG. 5 . The recess region is followed by an entry region defined by converging sidewalls  49  and  50 ; an apex region defined by minimum groove width points  51  and  52 ; a hold region defined by diverging sidewalls  53  and  54 ; and groove cap or termination region defined by surfaces  57  and  58  and by triangular element  63 . The groove sidewall angles are defined as follows: angles  102  and  103  are the first and second entry region convergence angles respectively; and angles  104  and  105  are the first and second hold region divergence angles respectively. The triangular element  63  is part of the groove cap and it may be kept in place or it may be removed with no impact on the operation of the connector system. 
         [0009]    In  FIG. 2 , first mating groove  25  in the first concrete block  130  mates with first split-tongue element  18  of lateral connector, item  17 . The first mating groove  25  shown is comprised of four regions arranged sequentially in the direction  30  of tongue insertion into the groove. These regions are: a recess region defined by recess upper surfaces  59  and  60  to accept base plate extensions  45  and  46  in  FIG. 4 ; an entry region defined by converging sidewalls  49  and  50 ; an apex region defined by minimum groove width points  51  and  52 ; a hold region defined by diverging sidewalls  53  and  54 , and groove cap or termination region  57  and  58 , and by triangular element  63 . The groove sidewall angles are defined as follows: angles  102  and  103  are the first and second entry region convergence angles respectively; and angles  104  and  105  are the first and second hold region divergence angles respectively. The triangular element  63  is part of the groove cap and it may be kept in place or it may be removed with no impact on the operation of the connector system 
         [0010]    In  FIG. 3 , items  49 ,  51 , and  53  form the second sidewall and items  50 ,  52  and  54  form the first sidewall of its groove. Similarly, in  FIG. 4 , items  49 ,  51 , and  53  form the second sidewall and items  50 ,  52  and  54  form the first sidewall of its groove. 
         [0011]    In  FIG. 1 , the base plate  32  provides vertical support for those portions  108  and  109  that overhang the normal connector. Base plate  32 , in conjunction with base plate extensions  55  and  56  in  FIG. 1 , act to limit the extent to which the split-tongue can be drawn into its mating groove and, hence, set the location of the fully inserted split-tongue past the apex and the associated residual split-tongue arm deflection. 
         [0012]    In  FIG. 2 , the base plate extensions  45  and  46  of base plate  20  serve two functions:
       1. limit the extent to which the split-tongue can be drawn into the groove and, hence, set the location of the fully inserted split-tongue past the apex and the associated residual split-tongue arm deflection,   2. provide vertical structural support to those portions  28  and  29  of the floor boards that overhang the connector in  FIG. 2 .       
 
         [0015]    During connector element insertion into its mating groove, the outward facing nubs on the flexible arms contact the converging walls of the mating groove entry region causing the arms to bend or deflect inward. The maximum deflection occurs when the arm nubs reach the groove apex. The maximum arm bending stress occurs this point, and consequently, the groove minimum width at the apex is selected to avoid significant plastic deformation of the flexible arms as they pass the groove apex during split-tongue insertion. 
         [0016]    Continued insertion of the tongue past the groove apex causes the nubs to contact the diverging walls of the hold region and the associated arm deflection to decrease. The connector becomes fully inserted into its mating groove when the base plate  32  and its extension  56  in  FIG. 5  rest on the groove upper recess surfaces  47  and  48  in  FIG. 3 . The residual arm deflection, i.e., the split-tongue arm deflection at full insertion, though less than that maximum arm deflection associated with the nubs at the groove apex, is significantly not zero. 
       SUMMARY OF INVENTION 
       [0017]    The present invention describes the manner in which the base plate  32  and first and second base plate extensions  55  and  56  respectively of normal connector  31  in  FIG. 1  can be used in conjunction with mating groove recess regions  47 ,  48 ,  117  and  188  to accommodate variations in flooring thickness variations due to manufacturing tolerances. 
         [0018]    The invention addresses the fact that in cases where the flooring thickness manufacturing tolerances are reduced to the point that acceptable planar flatness of the upper decorative surfaces  2  and  4  of floor boards  1  and  3  respectively in  FIG. 1  can be maintained without special accommodation, the recess distance  122  in  FIG. 3  can be reduced to zero, essentially eliminating the recess region from the groove geometry. 
         [0019]    The invention addresses the fact that in a lateral split-tongue connector system, elimination of the mating groove recess regions allows the lateral connector to be employed to stack concrete blocks while avoiding direct block-to-block contact with the attendant potential for block mechanical failure 
         [0020]    The invention addresses alternate mechanical means of attaching a lateral split-tongue connector to solid entity or attaching a normal split-tongue connector element to a floor board. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0021]    Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which similar element are given similar reference numerals. 
           [0022]      FIG. 1  is a side view showing assembled and disassembled views of the normal connector system disclosed in the prior patent 
           [0023]      FIG. 2  is a side view showing assembled and disassembled views of the lateral connector system disclosed in the prior patent 
           [0024]      FIG. 3  shows the mating groove for a normal connector shown in  FIG. 1  and as disclosed in the prior patent. 
           [0025]      FIG. 4  show the mating groove for a lateral connector shown in  FIG. 2  as disclosed in the prior patent. 
           [0026]      FIG. 5  shows the manner in which the recess groove can be made to accommodate the large variations in floor board thickness due to manufacturing tolerances. 
           [0027]      FIG. 6  shows a lateral connector element used to connect two concrete blocks 
           [0028]      FIG. 7  shows a half lateral connector attached permanently to a first solid entity by a staple and a second solid entity attached temporarily to the half lateral connector via a single split-tongue that interacts with a mating groove in the second solid entity. 
           [0029]      FIG. 8  shows a half lateral connector attached permanently to a first solid entity by means of a stud glued into a rectangular groove, and a second solid entity attached temporarily to the half lateral connector via single split-tongue that interacts with a mating groove in the second solid entity. 
           [0030]      FIG. 9  shows a half normal connector attached permanently to a first solid entity by means of a stud glued into a rectangular groove, and a second solid entity attached temporarily to the half lateral connector via single split-tongue that interacts with a mating groove in the second solid entity. 
           [0031]      FIG. 10  shows a half normal connector attached semi-permanently to a first solid entity by means of a finned protrusion. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0032]    The invention disclosed in U.S. Pat. No. 9,322,421 recognizes the fact that the normal groove recess regions  47  and  48  in  FIG. 3  can be used to allow the normal connector in  FIG. 1  to vertically align decorative surfaces  3  and  4  of flooring elements  1  and  2  in  FIG. 1 , when the thickness of the flooring elements differ significantly from each other due to manufacturing tolerances. 
         [0033]      FIG. 5  shows a case in which the height  126  of first flooring element  1  is significantly greater than the height  127  of second flooring element  3 . Should these flooring elements rest directly on a flat underlying substrate, this difference in floor heights would result in an unacceptable non-planar alignment of the decorative surfaces of the two flooring elements. 
         [0034]    To avoid this condition, the flooring elements are made to rest indirectly on the underlying planar substrate through the intermediate action of the normal connector element, and with the geometry of the normal connector element and its mating split-tongue groove being modified so as to accommodate the difference in flooring height so that the decorative surfaces are brought into planar alignment. 
         [0035]    In  FIG. 5 , the lower surface  124  of flooring element  3  with the smaller vertical height  127  is made congruent with the upper surface  125  of the first base support extension  56 . To bring the decorative surface  2  of flooring element  1  into vertical alignment with decorative surface  4  of flooring element  3 , recess vertical dimension  128  of flooring element  1  must be made essentially equal in value to vertical height dimension  127 . 
         [0036]    The recess distance  122  of first side flooring element  1  is equal to the difference between the vertical height  126  of flooring element  1  and vertical height  127  of flooring element  3 . In order for the both flooring elements  1  and  3  to be supported of the underlying substrate via connector element  31 , the thickness  126  of the base support  32  and first and second base support extensions  55  and  56  respectively must be greater than the recess distance  122 . 
         [0037]    When this condition is met, then the lower surface  111  of normal connector element  31  will be below the lower surface  112  of first floor element  1  and below the lower surface  124  of flooring element  124 . Consequently, only the lower surface  111  of normal connector  31  will be in direct contact with the underlying support substrate. 
         [0038]    It should be noted in  FIG. 5  that multiple nubs  110  have been added to the underside of base support  32  and first and second base support extensions  55  and  56  to increase the vertical thickness  126  of these elements. Since the magnitude of vertical distance  126  determines the maximum vertical difference in flooring heights  126  and  127  that can be accommodated by normal connector  31 , these nubs serve to increase the height difference that can be accommodated. 
         [0039]    The vertical height  126  is increased using multiple nubs for two reasons: 1) to reduce the cross sectional area of the connector and, hence its material cost, by eliminating the material that would be contained in the spaces between the nubs; and 2) to maintain and essentially constant material thickness over the connector cross section in order to simplify the extrusion die design. 
         [0040]    The embodiment shown in  FIG. 5  addresses the case in which the difference in vertical height between flooring elements due to manufacturing tolerances is large. In that case the recess region of the groove of the flooring element with the smaller height is eliminated and the recess region of the flooring element with the larger vertical height is made as small as can be consistent while still accommodating the large difference in flooring height. 
         [0041]    In the case in which the vertical height difference between flooring elements is small, the recess region can be eliminated from both flooring elements as long as the height difference is small enough so that the extent to which the decorative surface of the larger flooring element extends above that of the smaller flooring element is deemed to be acceptable. 
         [0042]      FIG. 6  shows a lateral connector used to connect two concrete blocks in the disassembled and assembled condition. Items  130  and  131  are first and second concrete blocks respectively; and associated lateral connector  17  has a first split-tongue element  18  and a second split-tongue element  19 . The two split-tongues  18  and  19  are formed on either side of base plate  20 . First split-tongue  18  has two flexible arms  21  and  22 , and second split-tongue  19  has two flexible arms  23  and  24 . The flexible arms  21 ,  22 ,  23 , and  24  have outward facing nubs  41 ,  42 ,  43 , and  44  respectively at their distal ends. First split-tongue  18  mates with groove  25  in concrete block  130  and second split-tongue  19  mates with groove  26  in concrete block  131 . Said nubs  41  and  42  contact the side-walls of said mating groove  25  of said split-tongue  18 ; and said nubs  43  and  44  contact the side-walls of the said mating groove  26  of said split-tongue  19 . 
         [0043]    In  FIG. 6 , the mating groove  25  of first concrete block  130  mates with first split-tongue  18  of lateral connector  17 . The groove is comprised of four regions arranged sequentially in the direction  116  of first split-tongue  18  into mating groove  25 . These regions are: an entry region defined by converging sidewalls  49  and  50 ; an apex region defined by minimum groove width points  51  and  52 ; a hold region defined by diverging sidewalls  53  and  54 , and groove cap or termination region  57 ,  58 , and  63 . The mating groove  26  of second concrete block  131  mates with the second split-tongue  19  of lateral connector  17 . The geometry of mating groove  26  is similar to that of mating groove  25  and consists of the same four regions arranged sequentially in the direction  115  of insertion of second split-tongue  19  into the groove. In the assembled condition, the first and second base extensions  45  and  46  serve to prevent direct concrete block to concrete block contact. 
         [0044]      FIG. 7  shows a half lateral connector  132  with a single split tongue element  18  used to temporarily connect first solid entity  133  to second solid entity  134 . The half solid lateral connector is permanently attached to the second solid entity via staple  135 . The first solid entity is attached temporarily to the half lateral connector via the interaction of the nubs  41  and  43  on the distal ends of flexible arms  21  and  22  with the side walls  137  of mating groove  136 . 
         [0045]      FIG. 8  shows a half lateral connector  132  with a single split tongue element  18  used to temporarily connect first solid entity  133  to second solid entity  134 . The half solid lateral connector has a slab-like stub  139  protruding from the lower surface  141  of its base support  20 . The slab-like stub is received by rectangular groove  138 . In the disassembled condition and just prior to partial assembly, a small quantity of liquid adhesive  140  is introduced into rectangular groove  138 . 
         [0046]    During partial assembly, half lateral connector  132  is permanently attached to second solid entity  134  by moving the half lateral connector in the direction of arrow  115  so that the slab-like stub enters into rectangular groove  138  causing liquid adhesive a 40  to flow into the clearance gap between the sides of the rectangular groove and the sides of the slab-like stub. Hardening of the liquid adhesive then permanently bond the half lateral connector to the second solid entity. The first solid entity is attached temporarily to the half lateral connector via the interaction of the nubs  41  and  43  on the distal ends of flexible arms  21  and  22  with the side walls  137  of mating groove  136 . 
         [0047]      FIG. 9  shows a half normal connector  145  with a single split-tongue  146  protruding from base support  32 , said single split-tongue having first and second flexible arms  21  and  22  with nubs  41  and  43  protruding in an outward facing direction from the distal end of each flexible arm respectively. The base plate has slab-like element  147  protruding from the location on support arm  32  where the second split-tongue  33  of normal connector  31  in  FIG. 1  would be located, and protruding in the same direction as said single split-tongue. 
         [0048]    First flooring element  1  with decorative surface  2  has rectangular groove  138  cut into the side of the board opposite said decorative surface. Prior to partial assembly, liquid adhesive  140  is place in said rectangular groove. During partial assembly, slab-like protrusion  147  is made to enter said rectangular groove so as to displacer said liquid adhesive into contact with the sides of said rectangular groove and said slab-like protrusion. After the liquid adhesive hardens, said slab-like protrusion and its monolithic half normal connector is permanently attached to said rectangular groove and said first flooring element into which it is cut. 
         [0049]    In  FIG. 9 , second flooring element  3  with decorative surface  4  has groove  40  cut into the side of the hoard opposite the decorative surface. Groove  40  contains four elements arranged sequentially in the direction  30  of split-tongue entry into said groove: a converging entry region defined by sidewalls  49  and  50 ; a minimum width apex region defined by side wall elements  51  and  52 ; a diverging region defined by sidewalls  53  and  54 ; and a cap region defined by elements  57 ,  58  and  63 . 
         [0050]    In  FIG. 9 , during full assembly, single split-tongue  146  on half normal connector  145  mates with groove  40  in second floor board  3  to connect floor boards  1  and  3 . 
         [0051]      FIG. 10  shows a half normal connector  148  with a single split-tongue  146  protruding from base support  32 , said single split-tongue having first and second flexible arms  21  and  22  with nubs  41  and  43  protruding in an outward facing direction from the distal end of each flexible arm respectively. The base plate has slab-like element  149  protruding from the location on support arm  32  where the second split-tongue  33  of normal connector  31  in  FIG. 1  would be located, and protruding in the same direction as said single split-tongue. 
         [0052]    In  FIG. 10 , first flooring element  1  with decorative surface  2  has rectangular groove  138  cut into the side of the board opposite said decorative surface. Slab-like protrusion  149  has fin-like elements  150  protruding from its two sides, said fin-like protrusions being canted back in direction opposite the direction of insertion  151  of slab-like protrusion  149  into rectangular groove  138 . 
         [0053]    In  FIG. 10 , during partial assembly slab-like protrusion  149  in inserted into rectangular groove  138  resulting in deformed fins  151 . Friction between the deformed fins and the walls of rectangular groove  138  acts to semi-permanently hold slab-like protrusion  149  in groove  138 . 
         [0054]    In  FIG. 10 , second flooring element  3  with decorative surface  4  has groove  40  cut into the side of the board opposite the decorative surface. Groove  40  contains four elements arranged sequentially in the direction  30  of split-tongue entry into said groove: a converging entry region defined by sidewalls  49  and  50 ; a minimum width apex region defined by side wall elements  51  and  52 ; a diverging region defined by sidewalls  53  and  54 ; and a cap region defined by elements  57 ,  58  and  63 . 
         [0055]    In  FIG. 10 , during full assembly, single split-tongue  146  on half normal connector  148  mates with groove  40  in second floor board  3  to connect floor boards  1  and  3 .