Abstract:
The disclosed invention is a portable floor comprised of interlocking floor panels which may be used for dancing, theatrical productions, musical performances, trade shows, and other settings where it is desirable to have a firm wooden floor surface. The disclosed invention enables a single person to install or disassemble the portable floor. It eliminates the need for storing any additional hardware to connect the panels to one another. No special tools are required to assemble or disassemble a floor. The floor is easy to assemble. Once the portable floor is assembled each panel is locked at two different places, thus firmly connecting the floor together. Panels may be added as desired to increase the size of the floor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     U.S. Provisional Application No. 60/312,294 was filed for this invention on Aug. 13, 2001 for which the inventor claims domestic priority. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to portable floors and more specifically to a system of interconnecting floor panels which connect together to form the floor surface. This portable surface may be used for a variety of different purposes, such as a portable stage, dancing, trade show displays and exhibits. 
     It is known that portable floors are often required for various purposes. For example, floors made specifically for dancing provide a great deal of recreation, exercise and personal enjoyment to their users. A preferred dancing surface is a hard, smooth, wood-like surface having a certain amount of spring. Although other surfaces may be danced upon, the action, feel and appearance of a surface made specifically for dancing is appreciated by both professional and novice dancer alike. However, a permanently-installed dance floor is expensive to install and can easily be damaged if used for other activities other than dancing. These problems were solved with the development of the portable dance floor. 
     Portable dance floors come in readily transportable sections which fit together to meet the needs of a particular function or activity. The floors of a hotel banquet room, recreation center, church hall, convention center or home living room may quickly be transformed to a dance floor through the installation of a portable dance floor. However, despite their convenience, portable dance floors present a unique set of challenges. A portable dance floor should install quickly and easily, provide a secure and smooth dancing surface, and be able to withstand the forces and wear and tear of people walking and dancing upon it. 
     Portable floors may also be used for setting up stages for theatrical or musical performances. A portable floor may also be used in a convention or trade show setting where a hard surface is desired for setting up a display or promotion. The requirements for these types of floor are frequently the same as for the portable dance floor described above. 
     Because portable floors typically come in sections, it is necessary to interconnect the various sections to make up the whole floor. Particularly in the case of dancing and theatrical productions, the sections of the portable floor should connect so there are no open seams, holes, or raised surfaces or objects which a dancer or performer might trip or stumble upon. In the case of dance floors, as a floor is danced upon, especially by professional dancers, a variety of forces are exerted upon the floor. Among these forces are lateral forces which will act to separate the individual sections of the floor unless the sections are adequately anchored together. However, the system employed to secure the sections together should be designed so that it not only prevents the sections from separating, but also allows for easy and rapid assembly and disassembly. 
     It is also desirable to have a connecting system which utilizes a minimum amount of hardware. Many users, including hotels, churches, etc., purchase portable floors for periodic use and enjoyment. However, the enjoyment and practicality of the device can be easily frustrated if hardware necessary to hold the floor together is misplaced, causing either delays in assembling the floor, or tempting the user to assemble the dance floor without all of the connecting hardware, which is not safe and can greatly reduce enjoyment of the floor. 
     Earlier forms of portable dance floors employed tongue and groove construction, where the tongue of one section fit within the groove of an abutting section, and the connection secured with a removable screw or bolt set through the tongue and groove. However, this type of connection makes assembly a slow a tedious process because each screw or bolt must be inserted and made up. Likewise, disassembly is slow and tedious. In addition, a screw or bolt head which is not entirely flush with the surface of the dance floor creates a potential hazard for the user. Finally, when the floor is not in use, the loose fasteners must be stored such that they are readily located for the next use. 
     In an effort to solve the above problems with bolted tongue and groove connections, U.S. Pat. No. 5,465,546 discloses a system for connecting a portable dance floor which does not use screws or bolts to join adjacent sections of the floor. The system disclosed in Pat. No. &#39;546 uses a main connector plate which is placed at the junction of four adjoining sections of the dance floor. Also disclosed in the &#39;546 patent is a tool used to disassemble the dance floor. While the system of the &#39;546 patent is superior to the bolted tongue and groove connections, it still has disadvantages. First, setting up and tearing down the floor can be difficult. As disclosed in the &#39;546 patent, at least two people are required to disassemble the floor, and a special tool is required. Second, the user of a portable dance floor with the disclosed system must continue to store a relatively small piece of hardware, i.e., the connector plates, which can easily be mislocated from the larger sections of the dance floor. 
     U.S. Pat. No. 6,189,283 discloses a portable dance floor in which adjacent panels are connected together with tongue and groove connections, where the tongue section is angled for locking into the groove. Assembly of the connecting sections requires lifting the panel to be joined and can be complicated by the different sizes of the panels. Disassembly of the floor can be difficult as well, as lateral forces applied to the surface of the floor can wedge the tongue elements tightly within the groove element, making it difficult to dislodge the tongue element. Moreover, each panel of this system has tongue elements protruding from the side of each panel, which can be broken off or otherwise damaged. Thus, while the connection system disclosed in the &#39;283 patent eliminates the problem of requiring additional hardware and/or tools for disassembly, it presents other potential problems. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a connection system for a portable floor which solves the problems identified above. 
     One embodiment of the disclosed portable floor comprises a plurality of rectangular panels. Each panel has a top surface which is used as the dancing or activity surface, and a bottom surface, which rests upon the ground, floor, or other support. The four sides of the rectangle comprise a first side having a first male edge, a second side adjacent to the first side, the second side having a second male edge, a third side having a first groove oriented along the long axis of the third side, and a fourth side, adjacent to the third side, the fourth side having a second groove oriented along the long axis of the fourth side. 
     Each male edge has two ends, comprising a locking end and a free end. The first groove is adapted for receiving the first male edge of a first adjacent panel, the first groove having an engagement member within the first groove for engaging the locking end of the first male edge. Likewise, the second groove is adapted for receiving the second male edge of a second adjacent panel, the second groove having an engagement member within the second groove for engaging the locking end of the second male edge. 
     The locking end of each male edge may comprise locking means such as a splined or beveled edge or a J-hook. These structures may be fashioned directly from the material comprising the end of the male edge, or the locking end may be attached to the male edge. The engagement member of each groove may comprise a female receiver adapted to receive the male spline or beveled edge. Alternatively, the engagement member may comprise a post generally oriented vertically at a right angle to the groove, the post configured to receive the J-hook of the male edge of an adjacent panel. 
     Once the locking end of the male edge of one panel engages the engagement member within the groove of an adjacent panel, the remainder of the male edge is fitted into the groove so that the entire length of the male edge is inserted into the groove. The two panels are further secured together with secondary locking means, which may comprise either a clip attached to one of the panels, or transition pieces which may be installed around the entire perimeter of the portable floor. Transition pieces are known in the art as beveled pieces going from the surface of the underlying floor to the level of the portable dance floor. The transition pieces lock onto the outward facing edges of the exterior panels, thus locking the entire floor. Disassembly of the floor is achieved by simply reversing the assembly steps. 
     The disclosed locking system enables a single person to install or disassemble a portable floor. It eliminates the need for storing any additional hardware to connect the panels to one another. No special tools are required to assemble or disassemble a floor. The floor is easy to assemble. Once the portable floor is assembled each panel is locked at two different places, thus firmly connecting the floor together. Panels may be added as desired to increase the size of the floor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is top view of a four panel section of the disclosed portable floor, using a spline type of locking end. 
     FIG. 2 shows a bottom view of a single panel of the disclosed portable floor. 
     FIG. 3 is a schematic view of the spline type of locking end. 
     FIG. 4 shows a bottom view of a four panel section of the disclosed portable floor, where the panels are framed a J-hook type of locking end is used. 
     FIG. 5 shows a bottom view of a four panel section of the disclosed portable floor, using a spline type of locking end. 
     FIG. 6 is a top view of an alternative embodiment of six panels of the disclosed portable floor, showing the placement of an “A” panel and a “B” panel. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring now to the drawings, FIG. 1 is plan view of the disclosed invention, showing a top view of one embodiment  10  of the disclosed portable floor. For purposes of illustration only, FIG. 1 shows a portable floor made up of four separate panels  12 , although the portable floor might be made up of any number of panels  12  so long as the resulting floor forms a rectangle or square. 
     Each panel  12  has a top surface  14 , a bottom surface  16  (not shown) and four sides  18 A through  18 D. The four sides comprise a first side  18 A having a first male edge  20 A, a second side  18 B adjacent to the first side  18 A, the second side  18 B having a second male edge  20 B, a third side  18 C having a first groove  22 C oriented along the long axis of the third side, and a fourth side  18 D, adjacent to the third side  18 C, the fourth side  18 D having a second groove  22 D oriented along the long axis of the fourth side  18 D. 
     FIG. 2 shows the bottom surface  16  of an individual panel  12 . The panel itself may be constructed from tongue and groove planking, using appropriate dance surfaces such as maple, ash or birch. Either solid planks or laminated planks may be used. A backing material may be applied to the bottom surface  16  of each panel  12  to provide a surface which does not slip on the surface underlying the portable floor. A suitable backing material is a sheet of luan mahogany of approximately one eighth inch in thickness, which may be glued, stapled or otherwise attached to the bottom surface  16 . Alternatively, rubber non-skid pads  24  may be attached to the bottom surface  16  of the panel  12  to inhibit sliding of the panel 
     As shown in FIG. 2, the first male edge  20 A has two ends, comprising a locking end  26 A and a free end  28 A. The free end  28 A may be tapered or angled. Likewise, second male edge  20 B has two ends, comprising a locking end  26 B and a free end  28 B. One acceptable locking end  26  is illustrated in FIG. 3, which discloses a spline as the locking end  26 . It is to be appreciated that while locking ends  26 A and  26 B could use a different mechanism, such as the alternative embodiment shown in FIG.  4  and discussed below, it is preferred, but not necessary, to use the same mechanism for locking ends  26 A and  26 B for all of the panels used within the same portable floor. 
     First groove  22 C is adapted to receive the first male edge  20 A of a first adjacent panel which may be attached to the panel  12  shown in FIG.  2 . First groove  22 C has an engagement member  30 C within the first groove for engaging the locking end of a first adjacent panel. The locking end of the first adjacent panel will be the same as locking end  26 A of panel  12  shown in FIG.  2 . Likewise, second groove  22 D is adapted to receive second male edge  20 B of a second adjacent panel which may be attached to panel  12 . Second groove  22 D has an engagement member  30 D within the second groove for engaging the locking end of a second adjacent panel. The locking end of the second adjacent panel will be the same as locking end  26 B of panel  12  shown in FIG.  2 . 
     FIG. 3 shows detail of one embodiment of locking end  26  and corresponding engagement member  30 . In this embodiment, locking end  26  comprises a spline and engagement member  30  comprises a slot adapted to receive the spline. The spline may be fashioned directly from the material comprising male edge  20 , which is preferably steel, aluminum or other appropriate metallic material. Alternatively, the spline may be fashioned from different material and attached to the end of male edge  20 . Male edge  20  may be attached to panel  12  in a variety of ways. Side  18  of panel  12  may be grooved such that the rear section  32  of male edge  20  is inserted into the groove and fastened with rivets, screws, or other appropriate fastening means. 
     Alternatively, the rear section  32  might be fastened to the bottom surface  16 , in which case the bottom surface would be routed so that rear section  32  is flush with the bottom surface. In this embodiment, the forward section  34  of male edge  20  must be adapted such that it is capable of engaging groove  22 , which should be located in the approximate middle of side  18  (i.e., the middle of the thickness of the panel). 
     Engagement member  30  is located within groove  22 , such that when two panels are desired to be attached together, locking end  26  is inserted into groove  22  until locking end  26  engages the engagement member  30 , at which point the remainder of male edge  20  is inserted into groove  22 . One embodiment of engagement member  30  is shown in detail in FIG. 3, in which the engagement member  30  comprises a slot adapted to receive the spline type of locking end  26 . 
     Different embodiments of the locking end and engagement member are shown in FIG.  4 . Locking end  26 ′ is a J-hook which may either be fashioned directly from the material comprising male edge  20 ′, which is preferably steel, aluminum or other appropriate metallic material. Alternatively, the J-hook may be fashioned from different material and attached to the end of male edge  20 ′. Alternatively, as indicated in FIG. 4, a J-hook may be attached to a side  18  of the panel, so the J-hook is a separate piece from the male edge  20 ′. The J-hook engages engagement member  30 ′. When a J-hook is used, engagement member  30 ′ comprises a post generally oriented at a right angle to groove  22 ′. 
     Secondary locking means are used to secure the panels together. One type of secondary locking means is locking clip  36 , which may be attached directly to the bottom surface  16  of panel  12 . The locking clip  36  may be a friction type lock which engages a lip or protrusion of the adjacent panel, acting to hold the free end  28  of the male edge  20  within groove  22 . 
     An alternative embodiment  10 ′ of the portable floor is also depicted in FIG.  4 . In this embodiment, the peripheral edge surface defined by the four sides  18  of a panel  12  may be bound and supported within a frame  38 , the frame comprising a first member  40 A, a second member  40 B, a third member  40 C and a fourth member  40 D. The outside surface of members  40 A and  40 B are configured to have a male edge  20 ′ extending outwardly from the member. Members  40 C and  40 D are each configured to have a groove  22 ′ extending inwardly into the member, the long axis of each groove  22 ′ coinciding with the respective long axis of member  40 C and  40 D. As with the embodiment disclosed above, each male edge  20 ′ has a a locking end  26 ′ and a free end  28 ′. Each groove  22 ′ has engagement member  30 ′ for locking end  26 ′ to engage. As depicted in FIG. 4, locking means  26 ′ may comprise a J-hook located at the end of male edge  20 ′, which engages engagement member  30 ′. When a J-hook is used, engagement member  30 ′ comprises a post generally oriented at a right angle to groove  22 ′. However, the locking end  26  and engagement member  30  depicted in FIG. 3 may also be used with the framed panel embodiment. 
     It is to be appreciated, from a review of FIG. 5 that the addition of the fourth panel  12 D interlocks the four panels  12 A,  12 B,  12 C and  12 D together, so that each panel  12  is locked onto two adjacent panels. Additional panels may be added as desired in a similar fashion until the desired dance floor size is achieved. When the desired size of floor is achieved by connecting a plurality of panels, each panel should be secured to two of the adjacent panels, thereby interlocking the panels. The top surfaces of the panels form a flush surface without seams, connectors, or edges extending above the surface of the floor. Transition pieces having matching tongue and groove components may be attached at the periphery of the floor, with a single transition piece connecting the outside edges of two panels, thereby locking the entire floor into place. For example, with respect to FIG. 5, once panel  12 D is locked into place, a transition piece is installed which locks onto the outside edges of panels  12 C and  12 D. This transition piece prevents panel  12 D from rotating or shifting in a clockwise direction. 
     FIG. 6 discloses another embodiment  10 ″ of the portable dance floor. In this embodiment, two different panels are utilized, an “A” panel  12  and a “B” panel  12 ′. The “A” panel  12  is the same as the panels disclosed above. The only difference with the “B” panel  12 ′ is that the orientation of locking end ″ and engagement member  30 ″ are changed so that the locking end  26 ″ is on the other side of male edge  20 ″. Engagement member  30 ″ is correspondingly shifted to the other side of groove  22 ″. With this embodiment, an “A” panel  12  will only mate with a “B” panel  12 ′ and vice-versa. FIG. 6 shows a floor of six panels would be configured. Additional panels would be added accordingly. It is to be appreciated that either the spline or the J-hook may be used for locking end  26 ″, and engagement member  30 ″ may be either the slot adapted to engage the spline, or the post adapted to engage the J-hook. 
     While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed.