Patent Publication Number: US-9833692-B2

Title: Games tables and corner assemblies for same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. Non-provisional application Ser. No. 15/363,962, filed Nov. 29, 2016, which claims benefit under 35 U.S.C. 119(e) of Provisional Application Ser. No. 62/281,950, filed Jan. 22, 2016, both of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to games tables, and more particularly to a games table with a unique corner assembly in which upper and lower corner members respectively embrace about upper and lower edges of an elongated perimeter frame member of the table and are clamped together to secure the frame member in place. Matable male and female features on the corner assemblies also enable stacking of two table top units to enable convenient switching of a games table between two modes of game play. 
     BACKGROUND 
     Games tables have long been known and widely used. This includes foosball (otherwise known as table football, table soccer, and several other names), billiards or pool, air hockey, and many others. Traditionally, these tables are made from either a wood or plastic frame, where 4 walls are attached together using nails or screws, and 4 legs are then attached to each corner also using nails or screws to elevate the height. These tables are traditionally sold non-assembled (i.e. flat-packed), so the end user needs to assemble the table themselves after purchasing it. 
     This historical design requires significant time to assemble. It requires the use or hammers and/or screwdrivers and/or Allen wrenches. Lower cost and mass market versions of these tables are also plagued by quality and workmanship issues whereby pre-drilled holes may not align perfectly and cause great hardship to the end-user to assemble the table. Once assembled, these tables take up a great amount of space as typically the legs cannot be easily removed without significant effort to unscrew the parts. As these tables are often used by children, the presence of nails and screws also creates a significant safety hazard. Many toy safety regulations prohibit the presence of sharp edges and points, including after conditioning treatment whereby the product is often broken apart. 
     Games tables can also be sold in both table and tabletop formats. Table format implies the presence of a set of legs (typically four) like a normal table, so that the unit is self-supporting and the game play surface is sufficient elevated for access by players typically in a standing position. Tabletop format implies the product is placed on a separate table to play, and either does not include legs or the legs are of very low height. 
     Games tables are incredibly popular all over the world, and there is desire for an improved design which will simplify assembly, improve safety, provide improved compactness and storability when not in use, and provide increased functionality easily used in either table or tabletop format. 
     The present disclosure provides an improved construction for a games table, greatly simplifying assembly, creating more functionality, improving safety, and allowing for more compact storage. The presently disclosed construction may be used for foosball (table football) tables, billiards or pool tables, air hockey tables, and other similar games tables, as well as multi games tables. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, there is provided a games table apparatus comprising: 
     a set of elongated frame members for placement end-to-end with one another to form a frame for supporting a game play surface; 
     a set of corner assemblies each configured for coupling together a respective adjacent pair of said elongated frame members at a respective corner of the frame; and 
     a set of table legs each connectable to a respective one of the corner assemblies in a position depending downward therefrom to support the frame and the playing surface in an elevated position; 
     each corner assembly comprising:
         an upper corner member having a first hub and a pair of open-bottom channels diverging outwardly from the first hub and arranged to embrace over upper edges of the adjacent pair of said elongated frame members at respective ends thereof; and   a lower corner member having a second hub and a pair of open-top channels diverging outwardly from the second hub and arranged to embrace around lower edges of the adjacent pair of said elongated frame members at respective ends thereof in alignment with the open-bottom channels that embrace over the upper edges of said adjacent pair of said elongated frame members; and       

     a tightening mechanism operable to force the upper corner member and the lower corner member toward one another against the upper and lower edges of the adjacent pair of said elongated frame members to clamp said adjacent pair of said elongated frame members together at the respective corner of the frame. 
     According to a second aspect of the invention, there is provided a games table apparatus comprising: 
     a set of table legs; 
     a table top unit comprising a set of elongated frame members that are situated end-to-end around a first game play area, and a plurality of corner units that each interconnect a respective adjacent pair of the elongated frame members at a corner of the first game play area, an upper end of each corner unit having a female opening therein at an upper end thereof and the corner units being connectable to the table legs for elevated support of the first game play area by said table legs; 
     a second game unit defining a second game related area and comprising at least one male insertion feature that is insertable downwardly into the female opening in the upper end of a respective one of the corner units to mate the male insertion with said respective one of the corner units in a manner supporting the second game related area in an elevated relation the first game play area. 
     According to a third aspect of the invention, there is provided a games table apparatus comprising: 
     a frame comprising a set of elongated frame members situated end-to-end around a game play area and a plurality of corner units each interconnecting a respective adjacent pair of the elongated frame members at a corner of the game play area; 
     a respective corner brace standing or standable upwardly from each corner unit; 
     a primary game play surface supported within said game play area for use in a first mode of gameplay; and 
     a secondary game play panel arranged for selective placement over the primary game play area in a useful position braced between the corner braces of the corner units to define a secondary game play surface for use in a second mode of gameplay. 
     According to a fourth aspect of the invention, there is provided a games table apparatus comprising: 
     a frame comprising a set of elongated frame members situated end-to-end around a game play area and a plurality of corner units each interconnecting a respective adjacent pair of the elongated frame members at a corner of the game play area; 
     a double-sided game play panel supported in the game play area by the frame; and 
     a set of table legs; 
     wherein each corner unit comprises hollow axial passages extending thereinto from both top and bottom ends thereof, each hollow axial passage being sized to accommodate receipt of an upper end of one of the table legs therein, whereby the frame is invertible between a first-side-up orientation mounted atop the table legs with a first side of the double-sided game play panel facing upward for a first mode of game play on said first side of the double-sided game play panel, and a second-side-up orientation mounted atop the table legs with a second side of the double-sided game play panel facing upward for a second mode of game play one said second side of the double-sided game play panel. 
     According to a fifth aspect of the invention, there is provided a games table apparatus comprising: 
     a set of elongated frame members for placement end-to-end with one another to form a frame for supporting a game play surface; 
     a set of table legs; 
     a set of corner units each configured for coupling together a respective adjacent pair of said elongated frame members at a respective corner of the frame, each corner unit comprising a split collet body having external threads and a downwardly-opening hollow interior sized for sliding receipt of a respective one of the table legs therein; and 
     a respective threaded collar for each table leg, the collar being slidable along the table leg and having internal threads matable with the external threads of the respective collet body, whereby rotation of the respective collar around the table leg in an advancing direction while in threaded engagement with the collet body tightens said split collet body around said table leg to clamp said table leg in place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One embodiment of the invention will now be described in conjunction with the accompanying drawings in which: 
         FIG. 1A  is a perspective view illustrating installation of a lower corner member of a games table corner assembly on a pair of adjacent frame members of the games table. 
         FIG. 1B  is a perspective view showing the lower corner member of  FIG. 1A  in its installed position on the adjacent frame members. 
         FIG. 2A  is a perspective view illustrating installation of a corresponding upper corner member with the lower corner member and adjacent perimeter frame members of  FIG. 1B . 
         FIG. 2B  is a perspective view showing the lower corner member of  FIG. 2A  in its installed position on the adjacent perimeter frame members. 
         FIG. 3A  is a perspective view illustrating installation of a generally cylindrical insert into aligned hubs of the upper and lower corner members of  FIG. 2B . 
         FIG. 3B  is a perspective view showing the generally cylindrical insert of  FIG. 3A  in its installed position seated within the hubs of the upper corner member. 
         FIG. 4A  is a perspective view illustrating coupling of an upright table leg to the generally cylindrical insert of  FIG. 3B . 
         FIG. 4B  is a perspective view showing the upright table leg of  FIG. 4A  in its installed position coupled to the generally cylindrical insert. 
         FIG. 5A  is a perspective view illustrating coupling of a threaded collar to a threaded lower end of the generally cylindrical insert of  FIG. 4B  in order to clamp together the upper and lower corner members and the associated upright table leg. 
         FIG. 5B  is a perspective view showing the threaded collar of  FIG. 5A  in its installed position mated with the generally cylindrical insert in abutment against the lower corner member. 
         FIG. 6A  is a perspective view illustrating installation of a finishing cap on the hub of the upper corner member of  FIG. 5B  in order to conceal the generally cylindrical insert received therein. 
         FIG. 6B  is a perspective view showing the finishing cap of  FIG. 6A  in its installed position, thereby reflecting a fully-assembled finished state of the corner assembly. 
         FIGS. 7A through 7J  illustrate elevational, top, bottom, cross-sectional and perspective views of the upper corner member. 
         FIGS. 8A through 8   j J illustrate elevational, top, bottom, cross-sectional and perspective views of the lower corner member. 
         FIGS. 9A through 9E  illustrate elevational, top, bottom and cross-sectional views of the generally cylindrical insert. 
         FIGS. 10A through 10I  illustrate elevational, top, bottom, cross-sectional and perspective views of the threaded collar. 
         FIGS. 11A through 11D  illustrate top, bottom, elevational and cross-sectional views of the finishing cap. 
         FIG. 12  illustrates an elevational view of the upright table leg. 
         FIG. 13  is a perspective view of a fully assembled games table employing four corner assemblies of the type illustrated in  FIG. 6 . 
         FIGS. 14A through 14D  illustrate a first games table whose corner assemblies having been assembled without upright table legs, and which is stacked atop a second leg-supported games table to switch between two different game playing modes. 
         FIGS. 15A through 15C  illustrate optional inverted installation of the finishing caps of  FIGS. 6 and 11 . 
         FIGS. 15D through 15G  illustrate use of the inverted finishing caps of  FIG. 15 a    to support a secondary game play panel over the primary game play area using corner braces that stand upwardly from the inverted finishing caps. 
         FIGS. 16A and 16B  illustrate optional removal of the finishing caps to support a secondary game unit in a position standing upward from the two corner units at one end of the games table. 
         FIGS. 17A through 17C  illustrate stacking of a legless games table assembly atop a leg-quipped table assembly, as similarly shown in  FIG. 14 . 
         FIGS. 18A through 18M  illustrate an invertibility of the games table, whereby a double-sided game play panel and associated frame can be mounted to the upright table legs in either one of two inverted orientations to enable two modes of game play from a singular games table. 
     
    
    
     In the drawings like characters of reference indicate corresponding parts in the different figures. 
     DETAILED DESCRIPTION 
       FIG. 13  shows a fully assembled games table  10  constructed in accordance with the present invention. In brief, the games table  10  features four upright legs  12  respectively coupled to four corner units  14 , which in turn are used to connect together four elongated perimeter frame members  16  that delimit a rectangular game play area  18  in which a horizontal panel  20  is supported by the frame members  16  to define a game play surface at a topside of the panel within the confines of the frame members  16 . The frame members  16  thus define perimeter side walls or barriers around the game play surface. This general structure may form the basis for any number of different types of gaming table, including, but not limited to, a foosball table where control rods are slidably supported by an opposing pair of the frame members  16  and goal openings are provided at the other opposing pair of the frame members, a pool or billiards table where pockets are provided at the corners of the game play surface just inside the corner units and at the midpoints of two opposing frame members, and an air hockey table in which goal openings are provided in an opposing pair of the frame members and an array of perforations are provided in the panel  20  and fed by a pressurized air source to create a cushion of air at the game play surface. In the illustrated embodiment, two of the four perimeter frame members  16  are longer than the other two in order to give the game play area an elongated rectangular shape. However the shape of the table may vary, for example including variation in the quantity of corner units, and variation in the quantity and relative dimensions of the frame members. 
     One particularly unique aspect of the games table is found in the structure and assembly of the corner units, which are now described in further detail with reference to  FIGS. 1 to 6 , which illustrate sequential steps in the assembly of each of the identical corner units  14 , and  FIGS. 7 to 11 , which illustrate the individual components that are assembled to define the finished corner units. 
       FIG. 1  shows an adjacent pair of the frame members  16  which are placed in proximity to one another in an end-to-end relationship at ninety degrees to one another to denote two perpendicular sides of a rectangular game play area. Each frame member of the illustrated embodiment is in the form of a flat rectangular board that is elongated in a longitudinal length direction L relative to a smaller width dimension W, and an even smaller thickness dimension T, of the board. Each frame member  16  resides in respective vertical pane with its length and width dimensions oriented respectively horizontally and vertically in this plane, and its thickness dimension oriented horizontally and perpendicularly transverse to this vertical plane. A longitudinal slot  22  spans the full length dimension L of each board on an interior side thereof that faces into the game play area  18  of the table in the fully assembled state thereof. The slot  22  resides nearer to a longitudinally oriented lower edge  16   a  of the frame member  16  than to a parallel longitudinally oriented upper edge  16   b  thereof. Near each end of each frame member  16 , a respective pair of blind holes  24  extends into each of the lower and upper edges  22   a ,  22   b  of the frame member  16 . 
     With continued reference to  FIG. 1 , each corner assembly includes a lower corner member  26  that features a hub  28  from which two open-top channels  30  diverge outwardly at ninety degrees to one another for respective mating with the lower edges  16   a  of the adjacent frame members. The angle of divergence of the frame members and the channels is ninety degrees in the illustrated embodiment where the play area is rectangular, but the angle may vary in other embodiments where the play area varies in shape and the corresponding number of corners. The lower corner member  26  is shown in isolation with greater detail in  FIG. 7 . Each open-top channel  30  features a bottom wall  32  and inner and outer side walls  34 ,  36  that stand vertically upright at opposing sides of the bottom wall  32 . Each channel  30  is open at the distal end  38  thereof situated opposite the hub from which the channel extends. The hub  28  features a cylindrically contoured outer wall  40  interconnecting the outer side walls  36  of the two channels  30  in a manner bulging convexly outward therefrom. The inner side walls  34  of the two channels are integrally joined by a concavely arcuate wall span  42 . A hollow axial passage  44  extends through the hub on the central axis  46  of the outer wall&#39;s cylindrical contour. This central axis  46  of the hub is offset outwardly from the intersection point of the longitudinal axes of the two open-top channels  30 . A set of three support flanges  48  jut into the hollow axial passage  44  from the outer wall  40  of the hub  28  at ninety degree intervals around the central axis  46  of the hub for reasons set out herein further below. One of these flanges  48  resides diametrically across the hollow axial passage  44  from the arcuate wall span  42 . 
     Gripping ribs  50  or fins are provided on both the inner and outer side walls  34 ,  36  of each open-top channel  30  at regularly spaced intervals therealong. Each gripping rib or fin spans the height of the respective side wall of the channel in a vertical direction parallel to the central hub axis  46 . Two column-shaped protrusions  52  protrude vertically upward from the bottom wall  32  of each open-top channel  30 . These protrusions  52  are spaced-apart from one another in the longitudinal direction of each channel by the same center-to-center distance as the two blind holes  24  in the lower edge  16   a  each of the frame members  16 , and are sized to enable insertion of these protrusions into these blind holes  24 . To accommodate this, a width of each open-top channel  30  measured perpendicularly between its parallel side walls  34 ,  36  slightly exceeds the thickness dimension T of each frame member  16 . The perpendicular distance between the gripping ribs or fins  50  on these side walls however is equal to or slightly less than the thickness of each frame member  16 , whereby slipping of the open-top channels  30  over the lower edge  16   a  of the respective frame member  16  provides a snug fit of the lower corner member  26  on the frame member  16  due to a slight interference fit therebetween, whereby the ribs or fins  50  on the opposing sides of the channel frictionally grip the interior and exterior sides of the frame member  16 . The lower corner member is a molded plastic part, and the frame members may be wooden boards, whereby the distal tips of the ribs or fins  50  are flexible or compressible to accommodate slight variations in the frame member thickness  16  and provide a snug friction fit therewith. The protrusions  52  may have a split-column shape, for example split by two perpendicularly crossing slots, to provide some radial compressibility to ensure the protrusions will fit within the blind holes  24  regardless of slight variations in the size or position of the preferably pre-drilled blind holes  24 . 
     The outer side wall  36  of each open-top channel is taller than the inner side wall  34  in a vertical height or depth direction measured perpendicularly to the bottom wall  32  of the open-top channel. Specifically, the height of the inside wall is equal to or slightly less than the distance from the lower edge  16   a  of the respective frame member  16  to the longitudinal slot  22  therein. With reference to  FIG. 1 , the lower corner member  26  is slipped upwardly into engagement with the two frame members  16  from therebeneath such that the protrusions  52  of each open-top channel  30  are inserted into the blind holes  24  in the lower edge  16   a  of the respective frame member and the walls  32 ,  34 ,  36  of the open-top channel embrace about the lower edge  16   a  of the frame member. The frictional fit of each open-top channel  30  on the respective frame member holds the lower corner member in place on the frame members while other corner unit components are subsequently installed in the manner described below, and the mating receipt of the protrusions  52  in the blind holes of the frame members prevent the frame members  16  from sliding longitudinally out of the open distal ends  38  of the open-top channels  30 . As shown in  FIG. 1B , the shorter height of the inside wall of each open-top channel prevents the channel from blocking access to the longitudinal slot  22  at the interior side of the respective frame member  16  for reasons set out herein further below. 
     Turning to  FIG. 2 , each corner unit also features an upper corner member  26 ′ of substantially the same structure and configuration as the lower corner member  26 , but employed in an inverted orientation relative thereto so that its two channels are open-bottom channels  30 ′ with closed top walls  32 ′ rather than open-top channels with closed bottom walls. The protrusions  52 ′ of the upper corner member  26 ′ thus project vertically downward from its top wall  32 ′. Unlike the illustrated lower corner member, the channels  30 ′ of the upper corner member of the illustrated embodiment don&#39;t feature shortened inner side walls, as the position of the longitudinal slot  22  near the lower edge  16   b  of each frame member  16  means that the inner side wall  34 ′ of each channel of the upper corner member  26 ′ can span more than half of the frame member&#39;s vertical height (i.e. the frame member&#39;s width dimension W) without interfering with the slot  22 . As shown, the inner side wall  34 ′ of each channel of the upper corner member  26 ′ may actually exceed the outer side wall  36 ′ in height, whereby the height of the open-bottom channel  30 ′ is greater at the inner side than at the outer side. 
     In the illustrated embodiment, the outer side walls  36 / 36 ′ of each corner member  26 / 26 ′ have a height that is half of the height (width dimension W) of each frame member  16  so that when the upper and lower corner members are fitted over the upper and lower edges  16   b ,  16   a  of the frame member  16  respectively, the outer side walls  36 ,  36 ′ of the two corner members abut one another at their distal edges. The height of the illustrated hub  28 / 28 ′ of each corner member  26 / 28  equals the height of the outer side walls  36 / 36 ′ of the channels  30 / 30 ′, and so the both the outer side walls  36 / 36 ′ of the channels and the outer walls  40 / 40 ′ of the hubs  28 / 28 ′ abut one another at a horizontal plane cutting through the frame members  16  at a vertically-centered height thereon. In other embodiments, the relative sizing of the channel side walls of the upper end lower corner members may vary from that of the illustrated embodiment. For example, the two side walls of each channel could be equal in height, and the outer side walls of the two corner member&#39;s need not necessarily meet one another. 
     Being of similar configuration, but inverted orientation, relative to the lower corner member, the upper corner member  26 ′ features a respective hub  28 ′ with an outer wall  40 ′ concentrically spanning about a central hub axis  46 ′ to enclose a respective axial through passage  44 ′, two open-bottom channels  30 ′ reaching outward from the hub to open distal ends  38 ′, an arcuate wall span  42 ′ joining together the inner side walls  34 ′ of the channels  30 ′, support flanges  48 ′ jutting into the axial through-passage from the outer hub wall, and gripping ribs or fins  50 ′ on the side walls  34 ′,  36 ′ of the channels. As shown in  FIG. 2B , the upper corner member is fitted over the adjacent pair of frame member  16  to insert the protrusions  52 ′ of the open-bottom channels  30 ′ into the blind holes  24  in the upper edges  16   b  of the adjacent frame members  16  so that the open-bottom channels  30 ′ embrace the upper edge  16   b  of the frame members in alignment with the open-top channels  30  that embrace the lower edges  16   a  of the frame members  16 . 
     Turning now to  FIG. 3 , with the upper and lower corner members  26 ,  26 ′ in place, a generally cylindrical insert  54  is inserted into a vertical through-bore that is defined by the aligned hollow axial passages  44 ,  44 ′ of the installed upper and lower corner members  16 ,  16 ′. The insert  54  features a hollow cylindrical body  56  spanning a substantial majority of the insert&#39;s axial height. A lower portion of the cylindrical body  56  features a set of axial slots  58  that split the body  56  into separated arcuate sections  60  that span respective portions of a circumferential path around the body&#39;s central longitudinal axis, thereby defining a split collet body at a lower portion of  62  of the insert near the bottom end thereof. The collet body features external threading  64 , which may start a short distance upward from the insert&#39;s bottom end, and the collet body may taper in diameter moving downward toward the bottom end of the insert from the threaded area, as shown at tapered area  66 . A head  68  of the insert at the top end of the cylindrical body  56  has enlarged diameter relative to the cylindrical body  56  in at least some directions so as to create an overhanging shoulder  70  at different sides of the insert for seating of this shoulder atop the inwardly jutting support flanges  48 ′ of the upper corner member  26 ′ when the insert is placed in the axial through-bore via the open top end of the axial passage  44 ′ of the upper corner member&#39;s hub  28 ′. 
     At one side of the insert, the head  68  features a stop tab  72  that juts further radially outward than the rest of the head  68 . A boundary wall spanning around the hollow axial passage  44 ′ of the upper corner member carries the support flanges  48 ′ on the inner periphery thereof, and also features a circumferential gap  74  at the area between where the two open-bottom channels  30 ′ extend outwardly from the hub  28  of the upper corner member. This gap  74  accommodates receipt of the insert&#39;s stop tab when the insert is lowered into this axial passage  44 ′ and seated atop the support flanges  48 ′. This engagement of the stop tab  72  into the gap  74  prevents relative rotation between the insert and the upper corner member. As shown in  FIG. 4B , in its seated position mated with the upper corner member, the insert reaches downwardly into and through the lower corner body  26  so that the externally threaded collet body near the bottom end of the insert  54  resides at least partially below the lower end of the lower corner member  26 . The cylindrical body  56  of the insert  54  has a hollow interior  76  opening thereinto from the collet-defining bottom end of the insert. The diameter of this hollow interior  76  equals or slightly exceeds an outer diameter of the table legs  12 , which are cylindrical in shape and may for example be made of metal tubing. With reference to  FIG. 4 , a top end  12   a  of a respective table leg  12  is inserted into the hollow interior  76  of the insert  54  of each corner assembly. 
     Turning to  FIG. 5 , an internally threaded collar  78  disposed around the table leg  12  is slid axially upward along the table leg  12  toward the externally threaded collet body at the bottom end of the insert  54 . Internal threading on the collar  78  is configured for mating cooperation with the external threading  64  of the insert  54 , whereby threaded advancement of the collar  78  on the insert  54  drives the collar  78  upward into abutment with the underside of the lower corner member  26 . During this threading of the collar onto the insert  54 , rotation of the insert is prevent by the stop tab  72 , and downward displacement of the insert  54  is prevented by the support flanges  48  of the upper corner member. Accordingly, the upward advancement of the of the threaded collar on the insert forces the lower corner member  26  upwardly toward the upper corner member  26 ′ to force the upper and lower corner members tighter together, thereby clamping the adjacent frame members  16  firmly between the channels  30 ,  30 ′ of the upper and lower corner members. The threading of the collar  78  onto the collet body also forces the arcuate sections  60  of the split collet body radially inward against the outer circumference of the table leg  12 , thereby firmly clamping the table leg in place. The insert  54  and cooperating collar  78  thereby form a tightening mechanism that serves to not only clamp the corner members  26 ,  26 ′ together, but also to clamp the table leg  12  thereto. 
       FIG. 10  shows more detail of the threaded collar  78 . An upper cylindrical portion  80  of the collar  78  features internal threading  82  that spans upward from a lower end of the cylindrical portion  80 . As shown, this internal threading may terminate before reaching the top end of the collar. At an intermediate point along the axial length of the cylindrical portion  80 , an exterior flange  84  projects radially outward from the cylindrical portion  80  of the collar around the full circumference thereof. The cylindrical portion  80  has an outer diameter that is less than a diameter of the lower corner member&#39;s hollow axial passage  44  at the bottom end of the lower corner member  26  so that threading of the collar  78  onto the exposed collet body of the insert  54  below the lower corner member  26  drives upper end of the collar&#39;s cylindrical portion  80  up into the hollow axial passage  44  of the lower corner member  26  in the annular space around the insert  54 . Under sufficient threading of the collar onto the insert, the exterior flange  84  of the collar  78  eventually abuts up against the underside of the lower corner member  26  to tighten the lower corner member  26  up against the bottom edge of the adjacent frame members  16  to thereby securely clamp the upper and lower corner members together with the frame members clamped securely between them. 
     Below its cylindrical portion  80 , the collar  78  features a tapered portion  86  that narrows toward the bottom end of the collar. The inner diameter of the collar, even where it is narrowest at the bottom end of the tapered portion  86 , slightly exceeds the outer diameter of the table leg  12  so as to be axially slidable thereon. However, the inner diameter at the bottom end of the tapered portion  86  of the collar is less than the default outer diameter of the split collet body of the insert  54 , whereby the threaded advancement of the collar  78  on the insert  54  drives the tapered lower portion  86  of the collar up over the tapered bottom end  66  of the insert, where the constricting inner diameter of the collar&#39;s tapered portion  86  forces the arcuate sections  60  of the collet body radially inward against the outer circumference of the table leg  12  in order to securely lock the leg in its fully inserted position in the corner assembly. As shown, the collar  78  may feature texture-providing grips, such as raised exterior ribs  88  lying axially of the collar at equally spaced intervals therearound at the area below the exterior flange  84 , in order to aid with tool-free manual rotation of the collar during engagement and disengagement thereof with the insert  54  during assembly and disassembly of the corner unit. 
     Turning to  FIG. 6 , a finishing cap  90  is installed in the hollow axial passage  44 ′ at the open top end of the upper corner member  26 ′ to close off this passage and thereby conceal the head  68  of the insert  54  beneath the cap  90 . A wall thickness of the outer wall  40 ′ of the upper corner member&#39;s hub  28 ′ decreases in a step-wise fashion at short distance downward from the open top end of the hub  28 ′, and the support flanges  48  for seating of the insert  54  are found at this lower diameter area. The step-wise decrease in diameter creates an annular interior ledge  92  a short distance above the elevation at which the support flanges  48 ′ are located. The cap  90  features a circular portion  94  whose outer diameter fits within the top end of the axial passage  44 ′, but exceeds the diameter of the axial passage  44 ′ at the reduced-diameter area thereof so that the cap  90  is seated atop the interior ledge  92  in the cap&#39;s installed position. 
     Like the head  68  of the insert  54 , the illustrated cap  90  features a radial tab  96  jutting outward from the otherwise circular remainder of the cap. The central span  42 ′ of the upper corner member that joins together the inner side walls  34 ′ of the open-bottom bottom channels  30 ′ features a rectangular cut-out  98  that reaches downward from the top end of the upper corner member  26 ′ down to the internally flanged and circumferentially gapped area thereof, and reaches inwardly into the hollow axial passage  44 ′. This cut-out  98  accepts insertion of the radial tab  96  of the cap. The cap and hub are configured to provide a snap fit between them, and a small notch  100  is provided in the top end of the hub wall  40 ′ of the upper corner member at a position diametrically opposite the cut-out  96  for prying of the cap from its installed position during disassembly of the corner unit. 
     Having described assembly of one corner unit from the upper corner member, lower corner member, the insert, the threaded collar, and the optional finishing cap, a complete games table is assembled by first assembling two corner units with three frame members to form a perimeter wall on three sides of a game play area, at which point the game play surface panel  20  can be slid into the longitudinal slots  22  of the three frame members, as enabled by the presence of a gap left between the inner side walls  34 ,  34 ′ of the upper and lower corner members. This gap is left open due to the fact that the height of the lower member&#39;s inner side wall is no greater than the distance from the lower edges  16   a  of the frame members  16  to the longitudinal slots  22  thereof, and the height of the upper member&#39;s inner side wall  34 ′ is no greater than the distance from the upper edges  16   b  of the frame members  16  to the longitudinal slots  22  thereof. With the panel  20  engaged into the slots  22  of the three assembled frame members, the fourth and final fame member can then be installed by assembling the two remaining corner units at the opposing ends of the final frame member. 
     The forgoing description discloses a corner assembly formed by five components, namely the upper corner member, lower corner member, the insert, the threaded collar, and the finishing cap. The clamping together of the upper and lower corner members via the insert and threaded collar vertically clamps the frame members in place between the corner members to prevent vertical separation of the frame members from the corner units, while the mating of the protrusions in the channels of the corner members with the blind holes in the frame members prevents horizontal separation, all without with use of screws or other separate fasteners to directly fasten the corner units to the frame members. Instead, the clamping together of the corner members with the manually-operated collar secures the corner units and frame members together without use of any tools or separate fasteners. 
     The above described assembly technique includes installation of the table legs  12  during assembly of the corner units so that a table top unit assembled from the frame members  16 , corner units  14  and game play surface panel  20  is elevated up off the ground by the leg  12  for standing play of a game on the game play surface. Alternatively, a legless games table unit for tabletop use can be assembled by following the same general process, but without installation of the table legs  12 , whereby the threaded collars  78  installed at the underside of the lower corner members  26  can be seated atop a desk, table or other suitable support surface. 
       FIGS. 14 and 17  illustrate yet another option in which two table top units are assembled, one with a corresponding set of legs, and one without. By removing the finishing caps  90  from the upper corner members of the leg-equipped games table  10 , this opens up the top end of the hollow axial passage  44 ′. The threaded collar  78  installed at the underside of each lower corner members  26  of the legless table top unit  10 ′ has an outer diameter at its bottom end that is slightly smaller than the open top end of the axial passage  44 ′ of each upper corner member  26 ′ of the leg-equipped games table  10 , whereby the threaded collars  78  at the underside of the legless table top unit serve as male features matably receivable in the female features defined by the open top ends of the corner units of the leg-equipped games table. Accordingly, the legless table top unit can be stacked atop the leg-equipped games table  10  by lowering the collar-defined male features of the legless table top unit into the female openings in the upper corner members of the leg-equipped games table  10 . When so mated, the cooperating male and female features block horizontal sliding of the legless table top unit off of, or out of alignment with, the underlying leg-equipped games table  10 . As shown in  FIGS. 14 and 17 , the removed finishing caps  90  from the leg-equipped games table can be reinstalled on the upper corner members of the legless upper table top unit. Accordingly, the use of two table top units as separable, stackable parts of an overall system in which only one set of legs is employed allows a user to easily and quickly switch between different modes of game play by simply adding or removing the legless table top unit to or from the leg-equipped table top unit, without need for any tools. So, as one non-limiting example, a foosball table top unit could simply be stacked atop an air hockey unit as desired in order to change from an air hockey mode of game play to a foosball mode of game play. 
     With reference to  FIG. 15 , the finishing caps  90  of the corner units are not only removable, but also invertible. Briefly turning back to  FIG. 11 , each cap  90  features a vertical perimeter wall  102  spanning fully around a horizontally oriented planar body  104  having flat first and second sides  104   a ,  104   b . The perimeter wall  102  extends perpendicularly from the flat first side  104   a  around the full perimeter thereof, thus surrounding the combined circular and tab-like areas of the planar body  104 . A pair of perpendicularly diverging walls  106  also extend perpendicularly from the first side  104   a  of the planar body  104 , but extend further therefrom than the perimeter wall  102 .  FIGS. 13 and 14  illustrate installation of the caps  90  in a second-side-up orientation in which the non-walled second side  104   b  of the planar cap body  104  faces upward and resides flush with the surrounding top end of the corner unit (i.e. flush with the top end of the upper corner member&#39;s hollow axial passage  44 ′ at the topside of the hub  28 ′, and likewise flush with the closed top walls  32 ′ of the open-bottom channels) when the perimeter wall  102  of the cap is seated atop the interior ledge  92  of the upper corner member&#39;s hollow axial passage  44 ′. In this second-side-up orientation, the diverging walls  106  projecting from the first side of the cap simply depend downwardly into the upper corner member  26 ′ behind the portion of the perimeter wall  92  that fills in the rectangular cut-out  98  in the central wall span  42  of the upper corner member  26 ′. The diverging walls  106  continue further downward behind this central wall span  42 , whereby the diverging walls  106  of each cap  90  are concealed within the respective upper corner member when the caps are installed in the second-side-up orientation. 
       FIG. 15  on the other hand illustrates installation of the caps  90  in a first-side-up orientation in which the non-walled second side  104   b  of the cap body  104  is seated atop the interior ledge  92  of the upper corner member  26 ′, and the pair of diverging walls  106  stand upwardly from the perimeter-walled first side  104   a  of the cap body that faces upwardly out of the upper corner member&#39;s hollow axial passage  44 ′. Since the diverging walls  106  are taller than the perimeter wall  102 , the diverging walls  106  reach upwardly past the open top end of the hub  28 ′ of the upper corner member  26 ′. Here, the second-side-up caps  90  can cooperate with a secondary game play panel  20 ′ to support this panel  20 ′ in a position overlying the primary game play panel  20  that is carried by the longitudinal slots  22  of the elongated frame members  16 . The secondary game play panel  20 ′ thereby enables a second mode of game play without any disassembly of the table legs  12 , corner units and frame members  16 . More specifically, the diverging walls  96  of each cap form a respective corner brace for embracing about a respective outer corner of the secondary game play panel  20 ′ at intersecting perimeter edges thereof. The portion  102   a  of the perimeter wall  102  of the cap  90  that spans between the two diverging walls  106  of the corner brace at the interior corner defined between these diverging walls  106  forms a support seat atop which the respective corner of the secondary game play panel  20 ′ is seated. Since this support seat portion  102   a  of the cap&#39;s perimeter wall resides at the radial tab  96  of the cap  90  that juts inwardly toward the game play area relative to the imaginary intersection point of the adjacent frame members  16  connected by the respective corner unit, the secondary game panel  20 ′ may be slightly smaller in area than the game play area of the primary game play panel  20 , and thus may be supported entirely atop the corner caps  90  without sitting on the elongated frame members  16 , as shown in the close-up view on the right side of  FIG. 15   b.    
     As described above,  FIGS. 14 and 17  illustrate stacking of a legless table top unit atop a leg-equipped games table to serve as a second game unit for enabling a second mode of game play without disassembly of the leg-equipped table.  FIG. 16  illustrates use of a different type of second game unit  108  with a leg-equipped games table, and once again employs uncapped corner units to support the second game unit. In the illustrated example, the second game unit is a basketball game unit  108  featuring a basketball backboard  110  with a basketball net  112  attached to a front face of the backboard. The backboard  110  is supported by a pair of support arms  114  that extend downwardly from the lower end of the backboard  110  at opposing side edges thereof. A lower end  114   a  of each support arm  114  defines a male insertion feature for cooperating with female features of a respective corner unit at one end of the games table. 
     The lower end  114   a  of each support arm  114  is lowered down into the hollow axial passage  44 ′ of the upper corner member  26 ′ of the respective corner unit, where the lower end  114   a  of the support arm  114  is inserted further down into a mating female socket  116  provided in the threaded insert  54  of the corner unit. The female socket  116  of the insert  54  is more clearly visible in the isolated view of the insert  54  in  FIG. 9 , where the socket  116  can be seen to open into the head-equipped top end of the insert. The socket  116  terminates in a closed end wall  116   a  at an intermediate location along the axial length of the insert  54 . The lower end  114   a  of the support arm is seated atop the closed end wall  116   a  of the female socket  116  of the insert  54  in order to support the basketball game unit  108  in a working position standing upright from the table top unit of the leg-equipped games table. 
     The support arms  114  thus carry the backboard  110  in a vertical plane at an elevated position spaced above the primary game play panel  20  that is horizontally carried by the elongated frame members  16  of the table top unit. In both the instance of the stacked table top units of  FIGS. 14 and 17 , and the instance of the table top unit and upright basketball unit of  FIG. 16 , a secondary unit defining a second game related area on a second game play panel is supported in elevated relation to the first game play area of the primary game play panel  20 , and the second game unit is supported by the corner units of the frame that carries the primary game play panel  20 . In the example of  FIG. 16 , the second game play panel is the basketball backboard  110 , whose front side defines the second game play area. A user can dribble a basketball on the first game play panel  20 , and shoot the ball of the backboard  110  into the attached basketball net  112 . Other examples of secondary game play panels useful in an upright orientation over the primary game play panel would be a scoreboard display panel, or a ping-pong return panel that stands upright at the end of the primary game play panel  20  for cooperation therewith in a single-player ping-pong game. 
     The illustrated support arms  114  of the basketball game unit  108  are of longitudinally deviated shape, first extending upward from the two corner units at the respective end of the games table, then curving outwardly beyond this end of the table before turning vertically upright again in order to carry the basketball backboard in a vertical plane situated past the end of the games table, with the attached basketball net reaching back toward the primary game play area. However, with a scoreboard, return-board or other type of secondary game play panel, such offsetting of the secondary game play panel outwardly from over the primary game play panel  20  may not be necessary, and so support arms of other shapes (e.g. purely linear, vertically upright arms) may be employed. 
     The illustrated embodiment of the upper and lower corner members of each corner unit differ from one another only in the relative heights of the channel side walls, and thus share the same hub structure with same hollow axial passage and associated support flanges and interior ledge. Accordingly, just as the insert  54  can be seated within the hollow axial passage  44 ′ of the upper corner member  26 ′, the insert can likewise be seated within the hollow axial passage  44  of the lower corner member  26 . This allows use of the table top unit in either one of two inverted orientations. Accordingly, the primary game play panel  20  can be a double-sided panel presenting different indicia or surface characteristics on opposing first and second sides  20   a ,  20   b  of the panel  20 , whereby a first type of game can be played on the first side  20   a  of the panel than on the second side  20   b  thereof to enable different modes of game play simply by inverting the table-top unit on the table legs. 
       FIG. 18 b    shows a table top unit of the type described above that has initially been installed in a first-side-up orientation on the table legs for a first mode of game play. To invert the table top unit, one first unthreads the threaded collars from the inserts of the four corner units and then withdraws the table legs from the corner units, as shown in  FIG. 18 c   . Turning to  FIG. 18 e   , one then removes the four finishing caps  90  from the corner units, and withdraws the respective inserts  54  therefrom. The primary game play panel  20  and the frame formed by the elongated frame members and corner units surrounding the panel  20  are then inverted into a second-side-up orientation, as illustrated in  FIG. 18 g   . With the second side of the primary game play panel  20  now facing upward for use in a second mode of game play, the inserts  54  are reinserted downwardly into the through-bores of the corner units. The inserts are therefore now seated in what was formerly referred to as the ‘lower’ corner members of the corner units, which now actually define the top halves of the corner units due to the newly inverted position of the primary game panel  20  and associated frame. The table legs are inserted upwardly into collet bodies of the inserts  54 , and the threaded collars are engaged to the collets to firmly secure the corner members and table legs together. The finishing caps are reinstalled over the inserts in the hollow axial passages of the formerly lower (and now upper) corner members  26 , thereby completing the assembly of the games table with the primary game play panel  20  in the inverted or second-side-up orientation. In either orientation, the table top unit assembled from the primary game panel, elongated frame members and cooperating corner units can be used with the finishing caps  90  removed to enable support of a second table top unit stacked thereatop (as shown in  FIGS. 14 and 17 ) or support of a different type of second game unit (as shown in  FIG. 16 ), or used with the finishing caps  90  installed in the first-side-up orientation of  FIG. 15  in order to support a secondary game play panel  20 ′ between the corner braces  106  of the caps  90 . 
     It will be appreciated that stacked or other cooperating support of multiple game units atop the same set of table legs using cooperating male and female features at corners of the table-top units, support of a secondary game panel between braces at the corner units of the table top unit, and/or an invertibility of the table top unit for different modes of game play may be employed regardless of whether the corner units specifically employ the clamp-together multi-piece assembly of the type described in detail above. Similarly, embodiments of the clamp-together multi-piece corner unit assembly other than those specifically detailed above are also contemplated within the scope of the present invention. For example, while the illustrated embodiment employs threaded collars slidably and removably disposed on the table leg make the threaded connection to the insert, another embodiment may instead feature a direct threaded connection of the table leg to the insert. However, as described above, the use of a threaded collar  78  may present certain advantages, for example to enable the stackable functionality described above. As another example, the benefit of tool-free assembly may be recognized using the same clamped-together concept to tighten upper and lower corner members together across a frame member sandwiched between them regardless of whether the tightening mechanism specifically employs a threaded insert and cooperating threaded collar or table leg. Also, while the frame members in the illustrated embodiment are used to form boundary walls for the game play area that stand upward from the game play surface, similar assembly of corner units and frame members could be used to define an underframe for an overlying game play surface that is supported atop, and may overhang, the frame members. 
     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the scope of the claims without departure from such scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.