Patent Publication Number: US-2009223162-A1

Title: Connecting System For Surface Coverings

Description:
BACKGROUND OF THE INVENTION 
     This application claims the benefit under 35 U.S.C. §119(e) of prior U.S. Provisional Patent Application No. 61/033,979, filed Mar. 5, 2008, which is incorporated in its entirety by reference herein. 
    
    
     The present invention relates to surface-coverings, like flooring, and methods of installing the same. 
     Various types of glueless mechanical locking systems (including straight tongue and groove arrangements) have been utilized in the flooring industry. Flooring with glueless mechanical locking systems (tongue and groove arrangements) are becoming increasingly popular, as they are easy to lay, and, thus, it is not necessary to utilize highly trained personnel to lay such floor tiles. 
     Current floor systems have suffered, however, from disadvantages. One disadvantage experienced with current floor systems is that if each of the side edges of a plank includes a mechanical locking tongue or groove, once one of the side edges is connected to another similar plank, it is difficult to connect the other side edges of the plank with yet another similar plank. Lifting portions of the connected flooring is necessary to create a proper angle to connect the plank. This problem particularly accentuates itself while installing a click system floor in a very limited-free-space and/or confined area such as in corners of a room, under or around a door jamb, or under or around closets or kitchen islands, and the like. In these areas there is no room for lifting portions of the connected flooring to create the necessary angle to connect the plank. 
     Some current flooring systems have a mechanical locking tongue and groove on the first opposing side edges and a straight edge on the other opposing side edges. This type of flooring system, however, also includes certain disadvantages. For example, the straight side edges that are connected to one another may not be water tight and could potentially slide open to form a gap. If an adhesive is used, the adhesive can be pressed out of the seams and create messy seams. 
     Other flooring systems have flexible grooves that have some “give” to permit connecting without angling. The integrity of such systems, however, is questionable and there is difficulty in making such a joint. 
     Accordingly, there is a need to provide a connecting system for flooring and other surface-coverings, which is relatively inexpensive, provides an excellent connection between the planks, is easy to connect along each of the side edges of the planks, and/or is moisture resistant and provides an overall acceptable bond strength between two joined planks. 
     SUMMARY OF THE INVENTION 
     A feature of the present invention is to provide a plank or a plank comprising a tongue at a first end of the plank and a groove at an opposing second end of the plank, and the tongue and groove have profiles as described herein. The tongue can be defined, at least partially, by a vertical distal surface that is substantially vertical to the top and bottom surfaces, a top planar slanted surface extending away from the vertical distal surface toward the top surface, a vertical lip extending downwardly from a top surface of the floor plank, and a slanted tongue bottom extending away from the vertical distal surface toward the bottom surface. 
     In some embodiments, the tongue can comprise a channel disposed substantially between the top planar slanted surface and the top surface. A pinnacle rail can be provided that connects, or can be at the intersection of, the top planar slanted surface and the channel. The channel can comprise a channel bottom and a channel back. In some embodiments, the channel bottom can comprise a flat surface and the channel back can comprise a curved surface. The channel back can extend away from the channel bottom toward the vertical lip. According to various embodiments, the channel can comprise an angled surface that extends from the vertical lip to the channel back and forms an angle relative to the vertical lip that is from about 40° to about 50°. In some embodiments, the channel bottom can extend vertically below the pinnacle rail. In at least one embodiment, the channel back can extend laterally further away from the vertical distal surface than does the vertical lip. According to some embodiments, the pinnacle rail can comprise a flat top surface that can be parallel to the top surface of the plank. 
     According to various embodiments, a vertical shoulder can be provided that extends from the slanted tongue bottom to the bottom surface. According to some embodiments, the vertical shoulder can comprise an angled transition that merges into the bottom planar slanted surface. 
     According to various embodiments, the vertical distal surface can have a height that is from about 30% to about 60%, or from about 40% to about 50% of the height of the plank. In some embodiments, the vertical shoulder can be spaced further from the vertical distal surface than the vertical lip. 
     According to various embodiments, the groove can comprise a vertical distal surface that is substantially vertical with respect to the top and bottom surfaces, a top planar slanted surface extending away from the vertical distal surface toward the top surface, a vertical lip extending downwardly from the top surface, and a bottom planar slanted surface extending away from the vertical distal surface towards the bottom surface. In some embodiments, a latch can be disposed substantially between the top planar slanted surface and the top surface. The latch can comprise a latch bottom and a latch back. In some embodiments, the latch bottom can comprise a flat surface and the latch back can comprise a curved surface. In some embodiments, the latch can comprise an angled surface that extends from the vertical lip to the channel back and forms an angle relative to the vertical lip which can be from about 30° to about 60°, or from about 40° to about 50°. 
     In some embodiments, the latch back can extend away from the latch bottom toward the vertical lip. A slanted surface can be provided between the top planar slanted surface and the latch. The latch bottom can extend vertically below the slanted surface. 
     The vertical lip of the groove can extend laterally further away from the vertical distal surface than does the latch back. According to some embodiments, the vertical distal surface can have a height that is from about 30% to about 60%, or from about 40% to about 50% of the height of the plank. A vertical shoulder can extend from the bottom planar slanted surface to the bottom surface. According to various embodiments, the vertical shoulder can be spaced firther from the vertical distal surface than the vertical lip. The tongue can comprise a profile that is substantially complementary to the shape of the groove edge. 
     Another feature of the present invention is to provide a flooring system for flooring planks and other surface-coverings that do not require any connecting accessories such as an insert, spline, metal clip, or the like, and which permits easy and fast installation and flexibility. 
     Still another feature of the present invention is to provide a flooring system that has significant improvements with respect to ease of installation at confined areas, and includes a foolproof installation design and technique. 
     Another feature of the present invention is to provide a plank that can be easily connected to other planks. 
     Another feature of the present invention is to provide a flooring system that can avoid the use of the application of a wet adhesive composition. 
     Also, a feature of the present invention is to provide a surface-covering system that has the ability to withstand water damage, such as swelling, delamination, and weakening, can withstand heavy traffic wear, tearing, and gouging, and exhibits stain resistance, chemical resistance, and ease of maintenance. 
     Also, a feature of the present invention is a method for joining together plank joints. 
     Another feature of the present invention is to provide a joint system that combines mechanical locking and chemical welding to provide improved joint strength, ease of installation, and water sealability. 
     Also, a feature of the present invention is to provide a joining system that enables tongue into groove installation or groove into tongue installation. 
     Additional features and advantages of the present invention will be set forth in the description that follows, and, in part, will be apparent from the description that follows, or may be learned by practice of the present invention. The features and other advantages of the present invention will be realized and attained by means of the elements and combinations particularly pointed out in the written description and the claims. 
     To achieve these and other advantages, and in accordance with the purposes of the present invention as embodied and broadly described herein, the present invention, in some embodiments, relates to structural features of planks along interconnecting edges and/or surfaces of planks that comprise a tongue along a first edge thereof and a mating groove along a second edge thereof. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention, as claimed. 
     The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a flooring system according to various embodiments of the present invention; 
         FIG. 2  is a cross-sectional view taken along line II-II shown in  FIG. 1 . 
         FIG. 3  is an enlarged view of the tongue edge of the planks shown in  FIG. 2 . 
         FIG. 4  is an enlarged view of the channel shown in  FIG. 3 . 
         FIG. 5  is an enlarged view of the groove edge shown in  FIG. 2 . 
         FIG. 6  is an enlarged view of the latch shown in  FIG. 5 . 
         FIG. 7  is a cross-sectional view through two planks of a flooring system according to various embodiments of the present teachings. 
         FIG. 8  is an enlarged view of the connecting region edge profiles of the flooring system shown in  FIG. 7 . 
         FIG. 9  is an enlarged view showing a scale for the tongue edge shown in  FIGS. 2 ,  3 , and  4 . 
         FIG. 10  is an enlarged view of the groove edge depicted in  FIGS. 2 ,  5 , and  6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     According to various embodiments, the plank can comprise a generally rectangular shape, having opposing first and second ends extending along the width of the plank, opposing first and second longitudinal sides extending along the length of the plank, and opposing top and bottom surfaces. In some embodiments, the plank comprises a tongue edge at a first end of the floor plank and a groove edge at an opposing second end of the floor plank. The tongue edge can be defined, at least partially, by a vertical distal surface that is substantially vertical with respect to the top and bottom surfaces, and a top planar slanted surface extending away from the vertical distal surface toward the top surface of the plank. A vertical lip can be included that extends downwardly from the top surface of the plank, and a slanted tongue bottom extending away from the vertical distal surface towards the bottom surface. A channel can be disposed substantially between the top planar slanted surface and the top surface. A pinnacle rail can be provided that connects the top planar slanted surface and the channel and/or that can comprise an intersection of the top planar slanted surface and the channel. The channel can comprise a channel bottom and a channel back. In some embodiments, the channel bottom can comprise a flat surface and the channel back can comprise a curved surface. The channel back can extend away from the channel bottom toward the vertical lip. According to various embodiments, the channel can comprise an angled transition that extends from the vertical lip to the channel back and forms an angle relative to the vertical lip that is in the range of from about 40° to about 50°. In some embodiments, the channel bottom can extend vertically below the pinnacle rail. In some embodiments, the channel back can extend laterally further away from the vertical distal surface than does the vertical lip. According to some embodiments, the pinnacle rail can comprise a flat top surface that is parallel to the top surface of the plank. 
     According to various embodiments, the tongue can comprise a vertical shoulder that extends from the slanted tongue bottom to the bottom surface. According to some embodiments, the vertical shoulder can comprise an angled transition that merges into the slanted tongue bottom. 
     According to various embodiments, the vertical distal surface can have a height that is from about 40% to about 50% of the height of the plank. In some embodiments, the vertical shoulder can be spaced further from the vertical distal surface than is the vertical lip. 
     According to various embodiments, the groove edge can comprise a profile that is substantially or fully complementary to the shape of the tongue edge. The groove edge can comprise a vertical distal surface that is substantially vertical with respect to the top and bottom surfaces, a top planar slanted surface extending away from the vertical distal surface toward the top surface, a vertical lip extending downwardly from the top surface, and a bottom planar slanted surface extending away from the vertical distal surface toward the bottom surface. In some embodiments, a latch can be disposed substantially between the top planar slanted surface and the top surface. The latch can comprise a latch bottom and a latch back. The latch bottom can comprise a flat surface and the latch back can comprise a curved surface. In at least one embodiment, the latch can comprise an angled surface that extends from the vertical lip to the channel back and that forms an angle relative to the vertical lip, which angle can be from about 40° to about 50°. 
     The latch back can extend away from the latch bottom toward the vertical lip. A slanted surface can be provided between the top planar slanted surface and the latch. The latch bottom can extend vertically below the slanted surface. 
     The vertical lip can extend laterally further away from the vertical distal surface than does the latch back. According to some embodiments, the vertical distal surface can have a length that is from about 40% to about 50% of the height of the plank. 
     A vertical shoulder can extend from the bottom planar slanted surface to the bottom surface. According to various embodiments, the vertical shoulder can be spaced further from the vertical distal surface than is the vertical lip. The tongue edge can comprise a profile that is substantially or fully complementary to the shape of the groove edge. 
     According to some embodiments the first longitudinal side can include the tongue edge and the second longitudinal side can include the groove edge. 
     According to various embodiments, a flooring system is provided that can comprise at least two floor planks that detachably interlock together. Each of the planks can comprise a top surface, a bottom surface, opposing first and second ends extending along the width of the plank, and opposing first and second longitudinal sides extending along the length of the plank. The first end of each plank can comprise a tongue edge. The second end of each plank can comprise a groove edge. According to some embodiments, the first longitudinal side can also comprise a tongue edge and the second longitudinal side can also comprise a groove edge. According to some embodiments, the plank can include a protruding lip along the first longitudinal side of the plank and a shoulder extending along the second longitudinal side of the plank opposite from the first longitudinal side, as discussed in U.S. patent application Ser. No. 11/190,452, incorporated by reference in its entirety herein. The shoulder along one longitudinal side of one plank can be adapted to receive the protruding lip along a longitudinal side of a similar plank. Alternatively, the first longitudinal side and the second longitudinal side can comprise any of the tongue and groove profiles described in U.S. patent application Ser. No. 11/190,452. 
     In some embodiments, the first longitudinal side and the second longitudinal side of the plank can be a straight edge such that the edges of two mating planks can be butted together to be substantially coplanar or flush with each other. A chemical welding agent such as THF can then be applied on the butted joint to melt the plastic together (when the planks are thermoplastic) at the contact to provide excellent joint integrity in strength and water-sealability. Other joining materials can be used, like adhesives, especially when the plank is made from laminates like fiberboard, e.g., HDF or MDF. 
     The tongue edge of the first longitudinal side can comprise a vertical distal surface that is substantially vertical to the top and bottom surfaces, a top planar slanted surface extending away from the vertical distal surface toward the top surface of the floor plank, a vertical lip extending downwardly from a top surface of the floor plank, and a slanted tongue bottom extending away from the vertical distal surface towards the bottom surface. According to some embodiments, the vertical distal surface can have a height that is from about 40% to about 50% of the height of the plank. 
     In some embodiments, if a groove edge is provided in a second longitudinal side of the plank, the groove edge can comprise a channel. The channel can be disposed substantially between the top planar slanted surface and the top surface. The channel can comprise a channel bottom and a channel back that extends away from the channel bottom toward the vertical lip. A pinnacle rail can be provided which connects the top planar slanted surface and the channel. The channel bottom can extend vertically below the pinnacle rail. The channel back can extend laterally further away from the vertical distal surface towards the bottom surface. A vertical shoulder can be provided which extends from the slanted tongue bottom to the bottom surface. According to some embodiments, the channel bottom can comprise a flat surface and the channel back can comprise a curved surface. In some embodiments, the channel can comprise an angled surface that extends from the vertical lip to the channel back and forms an angle relative to the vertical lip that is in a range of from about 40° to about 50°. In some embodiments, the pinnacle rail can comprise a flat top surface that is parallel to the top surface of the plank. The vertical shoulder can comprise an angled transition. The angled transition can merge into the bottom planar slanted surface. According to some embodiments, the vertical shoulder can be spaced further from the vertical distal surface than the vertical lip. According to various embodiments, the vertical distal surface can have a height that is from about 40% to about 50% of the height of the plank. 
     The groove edge along the longitudinal side can comprise a vertical distal surface that is substantially vertical to the top and bottom surfaces, a top planar slanted surface extending away from the vertical distal surface toward the top surface, a vertical lip extending downwardly from the top surface, and a latch disposed substantially between the top planar slanted surface and the top surface. The latch can comprise a latch bottom and a latch back. The latch back can extend away from the latch bottom towards the vertical lip. The latch bottom can comprise a flat surface and the latch back comprises a curved surface. According to some embodiments, the latch bottom comprises a flat surface and the latch back comprises a curved surface. In some embodiments, the latch can further comprise an angled surface that extends from the vertical lip to the latch back and forms an angle relative to the vertical lip that is in the range of from about 40° to about 50°. 
     The groove edge along the longitudinal side can comprise a slanted surface between the top planar slanted surface and the latch. The latch bottom can extend vertically below the slanted surface. According to some embodiments, the slanted surface can comprise a flat top surface that is parallel to the top surface of the plank. The vertical lip can extend laterally further away from the vertical distal surface than does the latch back. A bottom planar slanted surface can extend away from the vertical distal surface towards the bottom surface. A vertical shoulder can extend from the bottom planar slanted surface to the bottom surface. 
     According to various embodiments of a system comprising a plurality of planks connected together, a first gap can be formed between the latch back of the second plank and the channel back and channel bottom of the first plank. In some embodiments, the span of the first gap can be in a range of from about 0.075 mm to about 0.20 mm, from about 0.10 mm to about 0.15 mm, or about 0.18 mm. According to some embodiments, a second gap can be formed between the top planar slanted surface of the first plank and the top planar slanted surface of the second plank. In some embodiments, the gap thickness of the second gap can be about 0.15 mm, or within a range of from about 0.05 mm to about 0.40 mm or from about 0.25 mm to about 0.30 mm. 
     According to various embodiments, a third gap can be formed between the vertical distal surface of the first plank and the vertical distal surface of the second plank. According to some embodiments, a fourth gap can be formed between the slanted tongue bottom of the first plank and the bottom planar slanted surface of the second plank. In at least one embodiment, a fifth gap can be formed between the vertical shoulder of the first plank and the vertical shoulder of the second plank. Each of the third, fourth, and fifth gaps can have a span in the range of from about 0.55 mm to about 0.025 mm, from about 0.04 mm to about 0.05 mm, or of about 0.50 mm. 
     In some embodiments of a flooring system, the tongue edge of a first of at least two floor planks is detachably lockable into the groove edge of a second of the at least two floor planks such that the latch of the second floor plank is secured between the vertical lip and the pinnacle rail of the first floor plank. 
     According to various embodiments, a plank can be extruded, or otherwise formed, in a manner to include a tongue on a first end and a groove on a second end. Other techniques can also be used to create the tongue and groove of the present teachings. In some embodiments, the tongue and groove can be milled or cut into, or molded onto, ends and/or sides of the plank. Other techniques known to one skilled in the art can also be used to provide the tongues and grooves of the present teachings. 
     An exemplary flooring system according to various embodiments of the present teachings is illustrated in  FIG. 1 . Three planks  20  can be joined to one another along their ends and edges to form a surface covering system, for example, a flooring system. Each plank  20  can be generally rectangular and have a first end  26 , a second end  28  that opposes first end  26 , a first longitudinal side  27 , and a second longitudinal side  29  that opposes first longitudinal side  27 . First end  26  and second end  28  can each extend the entire width of plank  20 . First longitudinal side  27  and second longitudinal side  29  can each extend the entire length of plank  20 . 
       FIG. 2  is a cross-sectional view of plank  20  taken through line II-II shown in  FIG. 1 . According to various embodiments, first end  26  can comprise a tongue edge  30  and second end  28  can comprise a mating groove edge  32  that is complimentary to tongue edge  30 . Tongue edge  30  and groove edge  32  can be disposed between opposing top surface  22  and bottom surface  24  of plank  20 . 
       FIG. 3  is an enlarged view of tongue edge  30 , of plank  20  shown in  FIG. 2 . Tongue edge  30  can be defined, at least partially, by a vertical distal surface  34 , a top planar slanted surface  36  extending from vertical distal surface  34  toward top surface  22  of plank  20 , a vertical lip  38  extending downwardly from top surface  22 , and a slanted tongue bottom  35  extending away from vertical distal surface  34  towards bottom surface  24 . Vertical distal surface  34  can be substantially vertical with respect to top surface  22  and bottom surface  24 . A channel  40  can be disposed substantially between top planar slanted surface  36  and top surface  22 . A pinnacle rail  52  can be provided that connects top planar slanted surface  36  and channel  40 . Pinnacle rail  52  can have a flat top surface  54  as shown. Tongue edge  30  can comprise a vertical shoulder  56  that extends from slanted tongue bottom  35  to bottom surface  24 . According to some embodiments, vertical shoulder  56  can comprise an angled transition  58  that extends to an intersection with slanted tongue bottom  35 . 
     According to various embodiments, vertical distal surface  34  can have a height that is from about 30% to about 60% or from about 40% to about 50% of the height of plank  20 . In some embodiments, vertical shoulder  56  can be spaced further from vertical distal surface  34  than is vertical lip  38 . 
       FIG. 4  is an enlarged view of channel  40  shown in  FIG. 3 . Channel  40  can comprise a channel bottom  42  and a channel back  44 . In some embodiments, channel bottom  42  can comprise a flat surface  46  and channel back  44  can comprise a curved surface  48 . Channel back  44  can extend away from channel bottom  42  toward vertical lip  38 . According to various embodiments, channel  40  can comprise an angled surface  50  that extends from vertical lip  38  to channel back  44  and forms an angle relative to vertical lip  38  that is in a range of from about 30° to about 60° or from about 40° to about 50°. In some embodiments, channel bottom  42  can extend horizontally below pinnacle rail  52 . In at least one embodiment, channel back  44  can be spaced further away from vertical distal surface  34  than is vertical lip  38 . According to some embodiments, pinnacle rail  52  can comprise a flat top surface  54  that can be parallel to top surface  22  of plank  20 . 
       FIG. 5  is an enlarged view of groove edge  32  shown in  FIG. 2 . Groove edge  32  can comprise a profile that is substantially or fully complementary to the shape of tongue edge  30 . Groove edge  32  can comprise a vertical wall  60 , a top planar slanted surface  62  extending away from vertical wall  60  toward top surface  22 , a vertical lip  64  extending downwardly from top surface  22 , a bottom planar slanted surface  80  extending away from vertical wall  60  toward bottom surface  24 , and a vertical bottom wall  82 . According to various embodiments, vertical shoulder  82  can be spaced further from vertical wall  60  than is vertical lip  64 . The vertical wall  60  can be substantially vertical with respect to top surface  22  and bottom surface  24 . A latch  66  can be disposed substantially between top planar slanted surface  62  and top surface  22 . Latch  66  can comprise a slanted surface  76 . 
       FIG. 6  is an enlarged view of latch  66  shown in  FIG. 5 . As can be seen in  FIG. 6 , latch  66  comprises a latch bottom  68  and a latch back  72 . In some embodiments, latch bottom  68  can comprise a flat surface  70  and latch back  72  can comprise a curved surface  71 . In some embodiments, latch  66  can comprise an angled surface  74  that extends from vertical lip  64  to latch back  72  and forms an angle, relative to vertical lip  64 , that is in a range of from about 20° to about 80° or from about 50° to about 70°. According to some embodiments, angled portion  74  can have an angle that is from about 40° to about 50°. 
     Latch back  72  can extend away from latch bottom  68  toward vertical lip  64 . The slanted surface  76  can be provided between top planar slanted surface  62  and latch  66 . Flat surface  70  can intersect slanted surface  76 . According to some embodiments, the slanted surface  76  can comprise a curved top surface  78  that is parallel to top surface  22  of plank  20 . 
     Vertical lip  64  can be spaced further away from vertical wall  60  than is latch back  72 . According to some embodiments, vertical wall  60  can have a height that is from about 30% to about 60% or from about 40% to about 50% of the height of plank  20 . 
     With reference again to  FIG. 1 , according to various embodiments, first longitudinal side  27 , like first end  26  discussed above, can comprise a tongue edge, and second longitudinal side  29 , like second end  28  discussed above, can comprise a mating groove edge. In another embodiment of the present invention, plank  20  can include a protruding lip along first longitudinal side  27  and a shoulder extending along second longitudinal side  29  opposite first longitudinal side  27 , as discussed in U.S. patent application Ser. No. 11/190,452, incorporated by reference in its entirety herein. In another embodiment, the first longitudinal side  27  and the second longitudinal side  29  can comprise a tongue and groove profile different from the first end  26  and the second end  28 , such as the tongue and groove profiles described in U.S. patent application Ser. No. 11/190,452. Essentially, any combination of groove and tongue profiles of the present invention can be present on each plank  20 . According to various embodiments, plank  20  can have a tongue edge at a first end, as described above, a groove edge at a second end, as discussed above, and the remaining two longitudinal sides can have straight edges with no mechanical lock or connecting system or conventional tongue/groove or conventional spline and groove connections or other connecting means. For purposes of the present invention, in at least one embodiment, the planks of the present invention have at least the tongue profile on at least a first end of each plank and a groove profile on at least a second end each of plank  20  (e.g., the opposing side), whereas first longitudinal side  27  and second longitudinal side  29  can have other connecting means, such as tongue/groove systems, mechanical lock systems, adhesive systems, and/or spline systems, and the like. In at least one embodiment, the tongue profile of the present invention is on one short edge of a plank and the groove profile of the present invention is on an opposing short edge of the same plank. 
     In accordance with various embodiments, the plank of the present teachings can have any length or width. The length of the plank can be defined as the distance between the first end of the plank and the second end of the plank. In some embodiments, the length of the plank can be, for example, from about 32 inches to about 52 inches, or about 48 inches. The width of the plank can be defined as the distance between the first longitudinal side of the plank and the second longitudinal side of the plank. In some embodiments, the width of the plank can be, for example, from about 5 inches to about 16 inches, or about 8 inches. The plank can have a height that is defined as the distance from the top surface of the plank to the bottom surface of the plank. In some embodiments, the height of the plank can be from about 0.25 inch to about 0.75 inch, or about 0.50 inch. The plank can be manufactured as a solid piece, can be extruded, can be injection molded, or can otherwise be formed, for example, with interior channels or voids of various dimensions. 
     With reference to the surface covering system shown in  FIGS. 7 and 8 , groove edge  32  of a first plank can be configured to receive tongue edge  30  of a second plank in a first relative orientation. Upon joining, no gaps or one or more gaps can exist between the connected edges. One of the two planks can be moved toward the other in a direction substantially perpendicular to the first and second ends of the planks. The opening of groove edge  32  receives the tongue edge  30  as the two planks are connected. The tongue edge  30  and groove edge  32  can be configured to ensure that two connecting planks can be firmly coupled to each other in a manner that avoids lateral movement in the horizontal plane (in a direction along the plane of the core) and in a manner that avoids movement in a vertical plane (in a direction perpendicular to the plane of the core). The joining of the planks using the profiles of the present invention can be achieved by laterally joining with no or slight angling the two planks by sliding them together. A little pushing force (e.g., tapping) may be used to accomplish this joining. The slight angling can be by lifting one non-joining edge of one plank (e.g., the plank where the tongue profile is entering the groove profile of another plank). The angle can be from 1° to 40°, such as 1° to 30°, 1° to 25°, 1° to 20°, 5° to 20°, 5° to 15°, 3° to 10°, and like, with the angle relative to the surface of the floor or substrate where the planks rest on. 
       FIG. 7  is a cross-sectional enlarged view of the connection between a first floor plank  86  and a second floor plank  88  in an exemplary flooring system  84  according to the present teachings. In flooring system  84 , two floor planks,  86  and  88 , are designed to mate with one another, and when mated, cannot move in a vertical or horizontal direction with respect to each other. Tongue edge  30  can comprise a profile that is substantially or fully complementary to the shape of groove edge  32 . As used herein, the phrase “substantially complementary” means that when operatively connected, the groove edge and the tongue edge can have one or more gaps therebetween, wherein, if gaps are provided, each gap provides a spacing between adjacent surfaces of the tongue edge and the groove edge and the spacing is no more than 11% of the thickness of the plank, such as from 1% to 11%, from 1.25% to 8%, from 1.4% to 6%, from 1.5% to 4%, from 1.7% to 3%, or from about 1.7% to 2% of the thickness (height) of the plank. The joined planks can have no play or can have play (e.g., lateral movement once connected). 
     As can be seen in  FIG. 7 , the tongue profile of plank  86  and the groove profile of plank  88  are not identical or even nearly identical with respect to mating surfaces. In other words, the tongue profile and the outline of the groove profile do not match each other like a square cube going into a recess having the same square dimensions. According to some embodiments, the planks of the present invention can have a tongue profile and a groove profile such that when the tongue profile and groove profile are connected to form a mechanical lock, a significant void volume is created by the gaps between the connected tongue and groove, especially compared to conventional tongue and groove profiles. This void volume, for instance, reflects the amount of open space that exists once the tongue edge and the groove edge are connected together and further shows the amount of open space which permits the tongue to engage the groove or vice versa in an easy fashion, and yet obtain and maintain a good mechanical lock. According to various embodiments, the groove profile does not at all mimic the tongue profile and the two profiles are significantly different or are not mirror images or perfect compliments of each other. 
       FIG. 8  is an enlarged view of one embodiment of the two connected planks,  86  and  88 , of flooring system  84  depicted in  FIG. 7 . As can be seen in  FIG. 8 , with reference to  FIGS. 3-6 , tongue edge  30  and groove edge  32  connected, vertical lip  64  of groove edge  32  can abut vertical lip  38  of tongue edge  30 , and a gap or void volume can exist between one or more of the remaining mating surfaces of tongue edge  30  and groove edge  32 . The gaps between the mating surfaces of tongue edge  30  and groove edge  32  for one embodiment are identified in  FIG. 8 . According to various embodiments, a first gap  90  can be formed between latch back  72  of second plank  88  and channel back  44  and channel bottom  42  of first plank  20 . A second gap  92  can be formed between top planar slanted surface  36  of first plank  86  and top planar slanted surface  62  of second plank  88 . In some embodiments, the gap thickness of second gap  92  can be from about 0.05 mm to about 0.40 mm. In at least one embodiment, the gap thickness of second gap  92  can be about 0.15 mm. 
     According to various embodiments, a third gap  94  can be formed between vertical distal surface  34  of first plank  86  and vertical wall  60  of second plank  88 . According to some embodiments, a fourth gap  96  can be formed between slanted tongue bottom  35  of first plank  86  and bottom planar slanted surface  80  of second plank  88 . In at least one embodiment, a fifth gap  98  can be formed between the vertical shoulder  56  of first plank  86  and vertical shoulder  82  of second plank  88 . 
     According to some embodiments, the void volume of first gap  90  can be at least 0.13 mm 2 ×L (e.g., 0.13 mm 2 ×L to 0.19 mm 2 ×L or more), wherein L is the length (in mm) of the tongue or groove along the end of the plank. Thus, the void volume (in mm 3 ) would be at least 0.13 mm 2  multiplied by the length of the tongue or groove (in mm) along the side of the plank. The length of the tongue and the length of the groove should be the same. For example, L can be from 50 mm to 200 mm. Preferably, the void volume (in mm 3 ) for the area designated  90  in  FIG. 8  is at least 0.19 mm 2 ×L or a void volume of from 0.13 mm 2 ×L to about 0.19 mm 2 ×L. The void volume of second gap  92  can be in the amount of at least 0.13 mm 2 ×L, or at least 0.40 mm 2 ×L, or at least 1.0 mm 2 ×L, for example, from about 0.20 mm 2 ×L to about 0.90 mm 2 ×L, or from about 0.40 mm 2 ×L to about 0.85 mm 2 ×L. The void volume of third gap  94  can be in the amount of at least 0.58 mm 2 ×L, or at least 1 mm 2 ×L, or at least 1.3 mm 2 ×L, for example, from about 0.58 mm 2 ×L to about 2.13 mm 2 ×L, or from about 0.75 mm 2 ×L to about 2 mm 2 ×L. The void volume of fourth gap  96  can be about 0.32 mm 2 ×L, or at least 0.5 mm 2 ×L, or at least 1 mm 2 ×L, for example, from about 0.4 mm 2 ×L to 2.85 mm 2 ×L, or 0.8 mm 2 ×L to about 2.2 mm 2 ×L. The void volume of fifth gap  98  can be in the amount of at least 0.07 mm 2 ×L or at least 0.2 mm 2 ×L, or a void volume of from about 0.07 mm 2 ×L to about 0.45 mm 2 ×L or from about 0.1 mm 2 ×L to 0.3 mm 2 ×L. 
     Again with reference to  FIGS. 3-6  and  8 , tongue edge  30  of a first of the at least two floor planks is detachably lockable into groove edge  32  of a second of the at least two floor planks such that latch  66  of second plank  88  is secured between vertical lip  38  and pinnacle rail  52  of first plank  86 . In some embodiments, the tongue profile and the groove profile are designed such that tongue edge  30  and groove edge  32  can be connected multiple times without a decrease in locking strength and also, or alternatively, without a decrease in the tightness of the mechanical lock between tongue edge  30  and groove edge  32 . With many previous conventional tongue and groove systems, the connecting of the tongue with the groove can only be done once or twice before the integrity of the tongue and/or groove dramatically decreases, resulting in a mechanical lock that is loose or faulty. In some embodiments of the present teachings, however, multiple connecting between tongue edge  30  and groove edge  32  is enabled while retaining connecting strength and tightness of the mechanical lock, for example, which is the same or better as compared to the first time that tongue edge  30  and groove edge  32  are connected together. 
     In some embodiments of the present invention, the planks can have a tongue profile and a groove profile that can be joined together by inserting tongue edge  30  of one plank into groove edge  32  of another plank or inserting groove edge  32  of a plank onto a tongue edge  30  of another plank, for example, while one plank is (or both planks are) lying flat on a surface. 
     Tongue edge  30  and groove edge  32  can be configured to have any suitable dimension, as long as tongue edge  30  is prevented from moving horizontally relative to the plane of the connected planks, once tongue edge  30  enters the cavity of groove edge  32 .  FIG. 9  shows exemplary measurements for various parts of tongue edge  30 , which measurements are designated H 1 , H 2 , H 3 , H 4 , and H 5 . According to various embodiments, H 1  can be 0.087 inch, H 2  can be 0.010 inch, H 3  can be 0.031 inch, H 4  can be 0.151 inch, H 5  can be 0.063 inch, H 6  can be 0.128 inch, and H 7  can be 0.065 inch. As an example, any one or more of these measurements can be (or vary) ±20%, ±15%, ±10%, ±5%, ±2%, ±1% from one or more of these particular measurements. 
       FIG. 10  shows exemplary measurements for various parts of groove edge  32 , which measurements are designated H 8 , H 9 , H 10 , H 11 , H 12 , and H 13 . According to various embodiments, H 8  can be 0.024 inch, H 9  can be 0.163 inch, H 10  can be 0.050 inch, H 11  can be 0.123 inch, H 12  can be 0.039 inch, and H 13  can be 0.040 inch. As an example, any one or more of these measurements can be (or vary) ±20%, ±15%, ±10%, ±5%, ±2%, ±1% from one or more of these particular measurements. It should be understood that the measurements shown are exemplary and for illustrative purposes only, and that other measurements can be used without departing from the scope of the invention. 
     The surface-covering of the present invention can be for flooring surfaces. The connecting and surface-covering system of the present invention can be used in a variety of applications, including, but not limited to, wall planks, ceiling planks, decks, patios, furniture surfaces, shelves, and other surface-coverings or parts thereof. The connecting system of the present invention can be used to connect a variety of surface-covering products. Any surface-covering product capable of being formed into a plank such that the surface-covering of the present invention can be used as part of this invention to form the surface-covering. For instance, laminate floor products can be connected by the connecting system of the present invention. Other floor products that can be connected together by the connecting system of the present invention include, but are not limited to, plastic-containing products, such as, for example, hard surface products. The plank of the present invention having a groove, optional shoulder, tongue, and optional protruding lip can be formed by milling/cutting techniques, extrusion, injection molding, and the like. In cellulosic-type products, the groove and optional shoulder can be machined into dimensions to receive the tongue and optional protruding lip of a similar plank. The planks of the present invention can also be formed by other molding techniques or other conventional technology used to form polymeric materials having designed shapes and forms. 
     The planks of the present invention can be made from a polymeric material. The polymeric material of the plank of the present invention can comprise a thermoplastic material, although other types of polymers can also be used. Examples of polymeric materials that can be used to form the plank of the present invention include, but are not limited to, vinyl-containing thermoplastics, such as polyvinyl chloride, polyvinyl chloride/rubber blends, polyvinyl acetate, polyvinyl alcohol, and other vinyl and vinylidene resins and copolymers thereof; polybutyleneterephthalate (PBT), polyethylenes such as low density polyethylenes and high density polyethylenes, polyethyleneterephthalate (PET), and copolymers thereof; styrenes, such as acrylonitrilebutadiene styrene (ABS), SAN, and polystyrenes and copolymers thereof; polypropylene and copolymers thereof; saturated and unsaturated polyesters; acrylics; polyamides, such as nylon containing types; engineering plastics, such as acetal, polycarbonate, polyamide, polysulfone, and polyphenylene oxide and sulfide resins and the like. One or more conductive polymers can be used to form the plank that has applications in conductive flooring and the like. The thermoplastic polymers set forth in Kirk Othmer (3 rd  Edition, 1981) at pp. 328 to 848 of Vol. 18 and pp. 385-498 of Vol. 16, (incorporated in their entirety by reference herein) can also be used as long as the resulting plank has sufficient strength for its intended purpose. The planks can contain optional ingredients like filler(s), like wood flour, cellulosic fibers, and/or conventional polymeric additives, like flame retardants, UV protectors, stabilizers, plasticizers, and the like. The polymeric planks of U.S. Pat. No. 6,617,009 B1 (incorporated herein in its entirety by reference) can be used herein, with the profiles of the present invention. 
     The plank of the present invention can also be made from other materials, such as solid wood, engineered wood, wood based material, like fiberboard (e.g., MDF, HDF), particle board, plywood, oriented strand board, chip board, various types of laminates, such as high-pressure laminates, natural, organic, recycled, or synthetic materials, solid wood, engineered wood, and the like. The planks can be made from any conventional materials used in the laminate or plank flooring industry. 
     With respect to the mechanical lock between the tongue edge and groove edge in the present invention, in one embodiment, there is no play between the tongue edge and groove edge once the tongue is locked into the groove or vice versa. Furthermore, in one embodiment, there is no biasing or spring force in the tongue edge and/or groove edge or tension created by the tongue edge locking into the groove edge or vice versa. In at least one embodiment of the present invention, the tongue profile and/or the groove profile are rigid enough such that the flexing of the profiles that mate with one another is essentially zero or is zero. In other embodiments, there can be a biasing or spring force or tension created when the tongue edge engages the groove edge or vice versa. 
     The planks of the present invention can include a top layer(s) on the core. For example, the top layer can include (a) a high pressure laminate construction that is comprised of an impregnated underlayer Kraft paper, a printed decorative layer, and an impregnated protective overlay compressed together with heat and pressure to become one single layer; (b) a wood veneer; or (c) a vulcanized cellulose layer that is made from a number of plies of paper treated with zinc chloride (or other agent), an acid to make the surfaces of the paper gummy and sticky, wherein the gummy plies are then pressed together. The plank of the present invention does not require a backing layer. Preferably, in at least some embodiments, the planks have no backing layer. In other embodiments, a conventional backing layer(s) can be present. 
     In addition, the decorative element such as wood grains and/or knots texture can be embossed (e.g., mechanical or engraved), wherein the design can then be directly printed on the surface using, for example, a non-contact type digital printing technology. Another option is to incorporate the pigments into an extrusion operation to create a wood grain look on the surface of the planks by disturbing the material flow in the extruder. The decorative element can be any design, like natural appearances, stone, brick, tile, ceramic, wood, marble, and the like or can be other designs common to or used by the floor industry. The design and overall upper layers can be textured, such as embossed in register with the design. 
     In one example, the top layer is a laminate on top of the core; a print layer can be affixed to the top surface of the core, wherein the print layer has a top surface and a bottom surface. The print layer can be a resin layer(s), or a resin impregnated printed paper, such as an aminoplast resin. The print layer can have a printed design. The printed design can be any design which is capable of being printed onto the print layer. The print layer can also be known as a decor print layer. The print layer can be prepared by rotogravure printing techniques or other printing means such as digital printing. Once a design is printed on the paper, the paper can then be impregnated with one or more resin(s) or mixtures thereof. The resin can be aminoplast. The resin can contain formaldehyde, such as urea formaldehyde or melamine formaldehyde, or a blend thereof. With respect to the optional laminate on top of the core, a print or design or decorative layer can be affixed to the top surface of the core, wherein the print layer has a top surface and a bottom surface. The print layer can be a resin impregnated printed paper. The print layer can have a printed design. The printed design can be any design which is capable of being printed onto the print layer. The print layer is also known as a decor print layer. Generally, the print layer can be prepared by rotogravure printing techniques or other printing means such as digital printing. Once the paper has the design printed on it, the paper can then be impregnated with a resin or mixtures thereof. The resin can be an aminoplast resin or can contain urea formaldehyde and/or a melamine formaldehyde, or other formaldehydes or other amines. The design or print layer can simulate any natural surface, such as wood, ceramic, concrete, tile, brick, stone, or non-natural looking surfaces. Essentially, any type of design, whether natural in appearance or not, can be used as the design on the print layer or can be the design located on the plank by methods described below or methods conventional in the area of surface coverings. 
     The print paper, also known as the Deco paper, can have the ability to have liquids penetrate the paper such as a melamine liquid (or other liquid resin or polymer) penetrating in about 3 to 4 seconds and also maintain a wet strength and even fiber orientation to provide good reinforcement in all directions. The type of paper used can be 50 to 75 g/m 2  weight and having a thickness of 0.05 to 0.25 mm. The saturation of the coating can be from about 50 g/m 2  to 75 g/m 2  or above or below these ranges. 
     Located optionally on the top surface of the print layer can be an overlay. The overlay which can also be known as the wear layer is an overlay paper, which upon being affixed onto the print layer, is clear in appearance. The overlay paper is, preferably, a high abrasive overlay which can contain wear resistant particles, such as aluminum oxide embedded in the surface of the paper. In addition, the paper can be impregnated with a resin(s) just as with the print layer. Various commercial grades of high abrasive overlays are, preferably, used such as those from Mead Specialty Paper with the product numbers TMO 361, 461 (70 gram/m 2  premium overlay from Mead), and 561 wherein these products have a range of Taber values of 4000 to 15000. The type of paper preferably used is about 46 g/m 2  and having a thickness of about 0.13 mm. 
     With respect to the print layer and the overlay, the amount of resin can be from about 60 to about 140 g/m 2 , such as from about 100 to about 120 g/m 2 . 
     As an option, an underlay can be located and affixed between the bottom surface of the print layer and the top surface of the core. The underlay can be paper impregnated with a resin(s) as described above with respect to the print layer and overlay. The underlay can be Kraft paper impregnated with a resin(s) (e.g., aminoplast, phenolics, phenolic formaldehyde resin, melamine formaldehyde resin, and the like), which is present in an amount of from about 60 g/m 2  to about 145 gm 2 , such as from about 100 g/m 2  to about 120 g/m 2  paper. The type of paper used can be about 145 g/m 2  and having a thickness of about 0.25 mm. Other paper can be used. 
     Other types of layers, which can be used in the present invention, such as wood veneer and vulcanized cellulose layers, can include the same components with respect to the conventional laminate surfaces. Wood veneers used as the top layer can be any type of species such as oak, maple, cherry, hickory, beech, pine, walnut, mahogany, chestnut, and teak and the like. The thickness of the veneer can be in the range of 0.005 inch to 0.250 inch. Preferably, the thickness of the veneer is in the range of 0.080 inches to 0.160 inches. The veneer on the top can be decorated with a printed design to highlight the grains or knots or to mimic certain wood species or to emboss the surface to create vintage appearance and the like. A radiation curing coating, like a urethane acrylate coating(s) or other protective coating(s), can be applied on the surface to provide surface properties such as scratch and wear resistance, scuff resistance, stain and/or chemical resistance. The coating can incorporate the abrasive resistance particles in the urethane or other coating for better surface protection. The coating can have an abrasion level of 500-1500 cycles per the NALFA test. 
     In addition, excellent moisture resistance and/or sound deadening qualities of this product can eliminate the need for underpadding, though use of underpadding is an option. 
     A further embodiment of the present invention relates to a plank which comprises the same plank described above but, in lieu of a top layer on top of the plank, a design is printed directly on the top surface of the plank using any number of printing techniques such as gravure printing, transfer printing, digital printing, flexo printing, and the like. Or, a printed thermoplastic film (e.g., PVC) or a wood veneer and the like can be laminated to a thermoplastic plank. A protective coating can then be placed on top of the printed design. Any type of protective coating or wear layer can be used, such as a polyurethane type coating with or without wear resistant particles in the coating. Thus, a plank would have a core, where the core has a top surface and bottom surface as well as opposing sides and a printed design directly on the top surface of the plank and optionally at least one protective coating on top of the printed design. The top surface of the plank as described earlier can have a textured surface as described above. 
     This type of plank can be made by extruding a material containing at least one polymeric material into the shape of the core and then printing a design directly on the top surface of the plank and then, optionally, applying at least one protective coating on top of the printed design and curing the protective coating. The protective coating can be applied by conventional techniques, such as with a curtain coater, direct roll coater, vacuum coater, differential roll coater, air knife coater, or spray apparatus. 
     In another embodiment of the present invention, a plank for surface coverings, such as flooring, has a core and an extruded layer on the top surface of the core, wherein the extruded layer includes at least one thermoplastic material with one or more pigmented compounds. The extruded layer on top of the extruded core can simulate various designs such as wood grain and the like. 
     The plank in this embodiment can be made by co-extrusion techniques which involve extruding the core and extruding either simultaneously or subsequently a layer containing at least one thermoplastic material with one or more pigmented compounds on top of the extruded core. 
     Another embodiment involves a plank having the same design as described above with a printed polymeric film, such as a PVC film placed on the top surface of the extruded core. The printed polymeric film can be a polymeric film having a printed design on the film wherein the film can be from about 10 to about 20 mil thick. One or more wear layers or protective coatings can be placed on top of the printed polymeric film. The polymeric film can be placed on top of the extruded core by typical lamination techniques, such as heating the printed film, then pressing the film to the extruded core to bond them together, or using glue to bond them together. 
     In one embodiment, where the core material is thermoplastic, like polyvinyl chloride, the core material, in this case, can be produced by metering the appropriate quantities of vinyl compound (or other polymer, like a rigid polymer, like a rigid vinyl chloride) and optional color concentrate into the feed end of an extruder. The extruder imparts the appropriate properties on the material through the manipulation of heating zones, cooling zones, screw temperature and rpm. The material then exits the extruder through a metal die which is machined with the intended profile design. As the material passes through the die the exiting mass (continuous in length) takes the shape of the machined profile. The profiled material exiting the extruder then enters a calibration unit which controls and if necessary manipulates critical dimensions through the cooling process. The calibration unit utilizes water temperature and flow rate to control profile measurements. The material exiting the calibration unit is a cooled continuous plank with specific profile dimensions. The cooled continuous plank is then fed into a cutter device which cuts the planks into specific lengths. 
     The wrapping unit can be utilized to adhere a decorative wear layer, or overlay (for example, a decorative paper with an electron beam cured acrylic resin or other curable EB resin) to a specific area of the extruded profile plank surface by means of heat, adhesive (for example, PU hot melt solid), pressure, and cooling. Extruded planks stacked in the appropriate orientation can be guided through multiple sections of a profile wrapping unit. As planks proceed through the unit, specific areas of the profile can be surface treated with plasma jets or other surface treatment (such as the bottom of the plank). At the same time, the PU hot melt solid is being subjected to sufficient temperatures, such as from 250° F. to 275° F. resulting in an output of melted PU adhesive. Additionally, the overlay, which is dispensed via roll form, is fed into the wrapping unit and subjected to low levels of heat (below 120° F.). After pre-heating, the overlay is then coated with roughly 9 grams/ft 2  of adhesive. In this case, the adhesive is maintained to a temperature of 250° F. in an applicator pan and dispensed evenly with an applicator roll. The wrapping unit combines overlay, adhesive and base plank together under pressure by means of rollers. Multiple sections of rollers continue to apply pressure with rolls and mate the overlay material to the surface of the profile in a gradual progression. Additional heat is applied in two additional sections, for instance, at temperatures of 100° F. and 121° F. respectively. As the wrapped intermittent planks exit the wrapping unit, the continuous overlay material is cut by saw to the corresponding plank lengths. Wrapped planks are then stacked on pallets until staging for the next process. 
     A trimming process can be used and trims back any excess overlay material and completes the plank width sizing step. Wrapped planks are stacked into an automated feed unit face down. The tongue side of the plank is used as a guide as the planks proceed through the cutting tools. A total of four cutting tools (2 tools per plank side) are used to trim off excess overlay. The trimming tools remove the overlay and the exposed ledge together, leaving a smooth vertical surface. Planks proceed through the trimming equipment to the end cut section. In this case the planks are cut to a specific length of 48″ with a clean vertical cut for the end seam. As planks exit the trimming unit they are staged for packaging. 
     With reference again to the drawings, the present teachings further relate to a method of connecting planks of the present teachings, to one another. The method of connecting planks  20  of the present teachings can include joining a plurality of planks  20  together as shown in  FIG. 1 . The method can comprise moving a first plank  20 , depicted at the top left of  FIG. 1 , laterally to the right, in the direction indicated by the directional arrows, toward a second plank  20  depicted at the top right of  FIG. 1 . The first plank is moved in a direction substantially perpendicular to its first end and substantially perpendicular to the second end of the second plank. The tongue edge along the first end of the first plank can enter the groove edge along the second end of the second plank. A third plank  20 , depicted below the first and second planks, can then be joined with the first and second planks by moving the third plank  20  toward the first and second plank  20 , in a direction substantially perpendicular to the first and second longitudinal sides of the first and second planks. In this manner, the groove edge along the second longitudinal side of the third plank  20  can engage and overlap the tongue edge along the first longitudinal sides of the first plank and the second plank, without having to lift or otherwise change the orientation of the first and second planks  20 . Alternatively, the third plank can be joined to the first plank and the second plank as described above, except that the first plank and the second plank can be moved toward the third plank, for example, by sliding. As discussed above, the first and second longitudinal sides of the planks can alternatively be provided with a different tongue/groove profile, or the edges can be connected in a conventional tongue/groove manner when tongue/groove connectors are present on these edges, or connected by using a spline, or the like. 
     Although use of a bonding agent is not necessary, a bonding agent/composition can, optionally, be applied or be used to connect two or more planks together. 
     With respect to the longitudinal sides or the short sides of the floor planks, which are joined together in some fashion, the floor planks of the present invention can have straight edges or can have a tongue and groove design or there can be some intermediate connecting system used to join the floor planks together such as a spline or other connecting device. Again, any manner in which floor planks can be joined together is embodied by the present application with respect to these two sides. For purposes of the present invention, the floor plank can have a tongue and groove design or similar connecting design on the side edges of the floor plank. Examples of floor planks that can have the connecting system(s) of the present invention include, but are not limited to, the floor planks described in U.S. Pat. Nos. 6,101,778; 6,023,907; 5,860,267; 6,006,486; 5,797,237; 5,348,778; 5,706,621; 6,094,882; 6,182,410; 6,205,639; 3,200,553; 1,764,331; 1,808,591; 2,004,193; 2,152,694; 2,852,815; 2,882,560; 3,623,288; 3,437,360; 3,731,445; 4,095,913; 4,471,012; 4,695,502; 4,807,416; 4,953,335; 5,283,102; 5,295,341; 5,437,934; 5,618,602; 5,694,730; 5,736,227; and 4,426,820 and U.S. Published Patent Application Nos. 20020031646 and 20010021431 and U.S. patent application Ser. No. 09/460,928, and all are incorporated in their entirety by reference herein. 
     Thus, in at least one embodiment, the present invention encompasses any type of joint or connecting system that adjoins edges of floor planks together in some fashion with the use of straight edges, grooves, channels, tongues, splines, and other connecting systems for at least two edges. Optionally, the planks can be joined together wherein at least a portion of the planks are joined together at least in part by an adhesive. An example of such a system is described in U.S. patent application Ser. No. 10/205,408, which is incorporated herein in its entirety. 
     The surface-covering system of the present teachings can be used in a variety of applications including, but not limited to, wall planks, ceiling planks, flooring surfaces, decks, patios, furniture surfaces, shelves, deck planks, fascia, partition planks, horizontal surfaces, table tops, chest tops, counter tops, and other surface-coverings or parts thereof. 
     Applicants specifically incorporate the entire contents of all cited references in this disclosure. Further, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range. In some embodiments, dimensions provided herein for various structural features are for illustrative purposes only, and are in no way intended to limit the scope of the present invention. 
     Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the present teachings disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the present invention being indicated by the following claims and equivalents thereof.