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You are an expert at summarizing long articles. Proceed to summarize the following text: 
REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part of U.S. patent application Ser. No. 08/870,101, filed Jun. 5, 1997, now abandoned the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a knock-down hand rail system. More particularly, the present invention relates to a unique knock-down hand rail system for use both indoors and outdoors. 
     Background of the Invention 
     The typical hand rail is formed of metal and susceptible to affects of weather or other environmental conditions causing the rail to rust and deteriorate. A disadvantage of these metal rails is that such rails require regular upkeep such as painting to prevent rust or complete replacement when the metal rusts away. 
     To overcome this, galvanized steel has been used to avoid rust and hopefully, eliminate regular upkeep. A disadvantage of galvanized steel is that the sheen is too bright and is distracting when used in environments such as auditoriums or stadiums. 
     A still further disadvantage of both the metal and galvanized steel hand rail systems is that their assembly is of a permanent nature. That is, once the rail structure is assembled, the rail is permanently fixed at that location in that configuration. 
     SUMMARY OF THE INVENTION 
     The present invention provides a knock-down hand rail assembly that is formed of both metal and plastic. The hand rail assembly is readily and easily assembled and disassembled. The hand rail is maintenance free and requires no paint or other upkeep. 
     The assembly of the present invention can be used in many applications both indoor and out. The hand rail assembly can readily be assembled anywhere. The assembly can also readily be disassembled to form a different hand rail structure configuration or to add more rails to the structure. Further, the hand rail can be readily disassembled to change the plastic for the purpose of changing colors of the rail or adding/subtracting signage provided on the structure. This is advantageous when using the invention in an auditorium setting. The ability to color code railings with seating makes it easier on attendees to find their seats during a game or show. The knock down hand rail assembly of the present invention includes at least two spaced apart vertical rails and at least two base supports for supporting the vertical rails in an upright position. Alternatively, the vertical rails may be supported by the ground using standard coring procedures. At least two spaced apart horizontal rails are provided and removably engaged with the vertical rails. These horizontal rails are preferably positioned above the base supports. Each vertical and horizontal rail is surrounded by removable and replaceable polymerized sheathing. The polymerized sheathing has an interior diameter equal to or greater than the outer diameter of each rail. Slip-on structural fittings are provided to removably engage the horizontal rails to the vertical rails. 
     In other preferred embodiments, a plurality of vertical and horizontal rails surrounded by polymerized sheathing and engaged by slip-on structural fittings can be used. These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the hand rail assembly of the present invention; 
     FIG. 2 is an exploded view of a preferred embodiment of the hand rail assembly of the present invention; 
     FIG. 3 is a cross-sectional view taken along line  3 — 3  of FIG. 1; 
     FIG. 4 is a perspective view of a second preferred embodiment of the hand rail assembly of the present invention; 
     FIG. 5 illustrates, from an oblique perspective, an alternative embodiment of the invention including a mesh infill; 
     FIG. 6 is a close-up detail of the corner of the assembly of FIG. 5; 
     FIG. 7 illustrates an alternative way of forming U-channels according to the invention to ensure that there are no gaps in the infill; and 
     FIG. 8 illustrates the use of clips as opposed to full-length channels, and an alternative corner gap-filling corner configuration. 
    
    
     DESCRIPTION OF THE INVENTION 
     With reference to FIGS. 1 and 2, a knock down hand rail system  10  is thereshown. In this first preferred embodiment, at least two spaced apart vertical rails  12 ,  14  are provided and supported in an upright position by base supports  16 ,  18 . These base supports  16 ,  18  provide removable and replaceable support with the ground  20  and are preferably secured to the ground  20  by bolts  22 . Alternatively, the hand rail assembly can be cored to the ground for support. 
     The hand rail assembly of the present invention also includes at least two spaced apart horizontal rails  24 ,  26  removably engaged with vertical rails  12 ,  14  and positioned above base supports  16 ,  18 . 
     As shown in FIG. 2, vertical rails  12 ,  14  are surrounded by removable and replaceable polymerized sheathing  28 ,  30 . This sheathing  28 ,  30  preferably slip fits about vertical rails  12 ,  14  and has an interior diameter equal to or greater than the exterior diameter of vertical rails  12 ,  14 . This aspect of the invention will be described in greater detail below. 
     As with vertical rails  12 ,  14 , corresponding horizontal rails  24 ,  26  are also surrounded by polymerized sheathing  32 ,  34  respectively. Additionally, this polymerized sheathing has an interior diameter that is equal to or greater than the exterior diameter of horizontal rails  24 ,  26 . As stated above, this slip fit of the polymerized sheathing  32 ,  34  about horizontal rails  24 ,  26  will be described in detail later. 
     Slip-on structural fittings  36 ,  40  are provided to removably engage horizontal rails  24 ,  26  to each other and to vertical rails  12 ,  14 . These slip-on structural fittings are preferably Hollaender structural fittings manufactured by The Hollaender Manufacturing Company, Cincinnati, Ohio. T-shaped slip-on structural fitting  36  may be provided to join horizontal rail  24  to horizontal rail  26  and include an extra opening for additional vertical rails if desired. T-shaped slip-on structural fitting  36  removably engages horizontal rails  24 ,  26  and polymerized sheathing  32 ,  34  by set screws  38 . 
     L-shaped Hollaender slip-on structural fittings  40  removably engage horizontal rails  24 ,  26  to vertical rails  12 ,  14 . L-shaped slip-on structural fittings  40  removably secure the rails to each other by set screws  42 . 
     With reference to FIG. 3, each slip-on structural fitting provided to removably secure the knockdown hand rail system  10  of the present invention typically includes a structural fitting  40  for securing horizontal rail  24  with polymerized sheathing  32  to vertical rail  14  with polymerized sheathing  30 . More specifically, interior diameter  44  of polymerized sheathing  32  is equal to or greater than exterior diameter  46  of horizontal rail  24 . Additionally, interior diameter  48  of L-shaped slip-on fitting  40  is equal to or greater than the exterior diameter  50  of polymerized sheathing  32 . Set screw  42  is preferably a counter bore knurled cup point set screw that securely fastens L-shape slip-on fitting  40  through polymerized sheathing  32  onto horizontal rail  24 . This structural assembly is typical of all rails, polymerized sheathing, and slip-on fittings of the present invention. 
     In a second preferred embodiment of the present invention, a third vertical rail  52  may be provided therewith. Vertical rail  52  is also preferably surrounded by polymerized sheathing  54  having an interior diameter equal to or greater than the exterior diameter of vertical rail  52 . Vertical rail  52  is typically provided with base support  56  for supporting vertical rail  52  in an upright position. Base support  56  may be secured to the ground  20  by bolts  22  as typically shown in base supports  16 ,  18 . 
     Vertical rail  52  with polymerized sheathing  54  may be provided with a cross-shaped slip-on structural fitting  70  for supporting additional horizontal rails  58 ,  60 . These horizontal rails  58 ,  60  are also preferably surrounded by polymerized sheathing  62 ,  64  respectively. As with all polymerized sheathing of the present invention, polymerized sheathing  62 ,  64  has an interior diameter equal to or greater than the exterior diameter of horizontal rails  58 ,  60 . Cross-shaped slip-on structural fitting  70  removably secures horizontal rails  58 ,  60  with polymerized sheathing  62 ,  64  to third vertical rail  52  with polymerized sheathing  54  by set screws  72 . Horizontal rails  58 ,  60  with polymerized sheathing  62 ,  64  are secured to vertical rails  12 ,  14  with polymerized sheathing  28 ,  30  by T-shaped slip-on structural fittings  66  with set screws  68 . 
     Proper assembly of the preferred present invention is as follows. Vertical rails  12 ,  14 ,  52  are spaced apart and supported in an upright position by base supports  16 ,  18 ,  56 . These base supports are removably secured to the ground  20  by any mechanical means such as bolts  22 . Removable and replaceable polymerized sheathing  28 ,  30 ,  54  is preferably slipfit about corresponding vertical rails  12 ,  14 ,  52 . T-shaped slip-on structural fittings  66  are slipped over polymerized sheathing  28 ,  30  to be secured and positioned later. 
     Horizontal rails  24 ,  26  are provided therewith and surrounded by corresponding polymerized sheathing  32 ,  34 . One end of each horizontal rail is secured to L-shaped slip-on fitting  40  by a corresponding set screw  42 . The opposite end of horizontal rails  24 ,  26  with corresponding polymerized sheathing  32 ,  34  is secured to a T-shaped slip-on fitting  36  by corresponding set screws  38 . The entire removably secured structure of these horizontal rails is then placed atop corresponding vertical rails  12 ,  14 ,  52  with polymerized sheathing  28 ,  30 ,  54  respectively. Remaining set screws  38 ,  42  removably attach the horizontal rail structure to the vertical rail structure. Lastly, horizontal rails  58 ,  60  are surrounded by polymerized sheathing  62 ,  64  respectively. Each horizontal rail  58 ,  60  with corresponding polymerized sheathing  62 ,  64  are removably secured between vertical rails  12 ,  14 ,  52  with corresponding polymerized sheathing  28 ,  30 ,  54  by slip-on structural fittings  66 ,  70 . Set screws  68 ,  72  removably engage these additional horizontal rails to the vertical rails at any point along the vertical rails. 
     An alternative embodiment of the present invention involves extension and bending of vertical rails  28 ,  30  to form horizontal rail  34 , as shown in FIG.  4 . That is, inner frame vertical rail  12 ,  14  is slip-fit into corresponding polymerized sheathing  28 ,  30  and is then bent to create a rounded comer and thereby extend into a horizontal rail. In this way, Hollaender fittings  40  would be eliminated and horizontal rails  24 ,  26  with corresponding polymerized sheathing  32 ,  34  would be replaced by extended vertical rails  12 ,  14  with polymerized sheathing  28 ,  30  to meet at Hollaender fittings  36 . In an extended version of this preferred embodiment, Hollaender fitting  36  may be provided to simply support vertical rail  52  with polymerized sheathing  54  to the singularly extended vertical rail  12  with corresponding sheathing  28 . In this embodiment, vertical rail  12  would then extend to form both exterior vertical rails  12 ,  14  and horizontal rails  24 ,  26 . A singular unit of polymerized sheathing would also extend about the singular rail and be bent to form rounded corners at the upper edges. 
     Alternative embodiments of the present invention may involve the use of only one top horizontal rail or several horizontal and vertical rails extending to create an elongated hand rail assembly  10 . It was envisioned that each vertical rail will be removably supported to the ground by a base or structure if necessary. Additional base structures are also shown in FIG.  4 . Moreover, each additional horizontal rail is preferably supported to the vertical rails by Hollaender slip-on structural fittings conforming to any shape necessary to create the overall structural shape of the hand rail assembly of the present invention. That is, the hand rail of the present invention may extend linearly, triangularly, circularly, or any other shape that may reasonably be configured. Moreover, each rail, vertical and horizontal, shall preferably be surrounded by polymerized sheathing having an interior diameter that is equal to or greater than the exterior diameter of the corresponding rail. 
     FIG. 5 illustrates, from a perspective view, an alternative embodiment of the invention generally at  102  including an infill disposed between the horizontal and vertical sheathing-covered rails  30  and  34 . Although the embodiment depicted in FIGS. 5 and 6 illustrate the use of a mesh panel  106  received by continuous channels  104 , it is readily apparent that the arrangement is conducive to the use of other types of infills, including clear and opaque plastics, glass, and meshes and perforated sheets having apertures of any scale, depending upon the application. 
     FIG. 6 is a close-up view of the way in which the channels  104  attach to the rails  30  and  34 , and the way in which infill  106  is received thereby. Preferably, a plurality of spaced-apart self-tapping fasteners  105  are used to adhere the U-channels  104  to the members as shown. Since the fasteners  105  must go through the U-channel material, sheathing and wall of the associated rail, it may be advisable to predrill holes for each fastener, as the case may be. Although the material used for the infill may not include a finished edge, particularly when mesh panels are used, it is preferable to have a peripheral seam  108  to provide a more finished look. In terms of materials, the U-channels  104  are preferably constructed of some type of corrosion-resistant metal such as aluminum, though other types of metals and even non-metals may be used, so long as they are of sufficient strength and durability. 
     To fill the triangular gap which would otherwise be left due to the difference in height between the sheath covered rails and corner/T-assemblies  40  and  46 , a configuration such as that depicted in FIG. 7 may alternatively be utilized. In this case, the U-channels  112  include relieved areas  114  such that, when assembled, a cleaner full corner appearance is achieved. In such a case, an infill having a square corner may be used, such as mesh screen  120  having a finished squared-off corner  122 . 
     FIG. 8 illustrates certain additional alternative configurations according to the invention, which may be used independently or in combination with other arrangements described herein. For example, in place of a continuous U-channel, clips  140  may alternatively be used, particularly if the edge of the infill is peripherally finished or otherwise continuous. As a further option, the edge of the infill may be scalloped, as shown at  150 . With such a shaped configuration, which may be used with clips or a continuous U-channel, the triangularly shaped gap shown in FIGS. 5 and 6 would be filled without having to grind or otherwise modify the U-channel or clip members. 
     The above description is considered that of the prefelted embodiment only. Modifications of the invention may occur to those of ordinary skill in the art. Therefore, it is understood that the embodiments shown in the drawing and described above are merely for illustration purposes and is not intended to limit the scope of the invention.

Summary:
The present invention provides a knockdown hand rail assembly that is formed of both metal and plastic. The hand rail assembly is readily and easily assembled and disassembled. The hand rail assembly is maintenance free and requires no paint or other upkeep. The assembly can be used in many applications both indoor and out. The hand rail assembly includes at least two spaced apart vertical rails, two base supports for supporting the vertical rails in an upright position and at least two spaced apart horizontal rails removably engaged with the vertical rails and positioned above the base supports. Each rail is surrounded by removable and replaceable polymerized sheathing having an interior diameter equal to or greater than the outer diameter of the rail. Each rail is also removably engaged to another rail by a slip-on structural fitting that preferably removably secures the rails by set screws.