Abstract:
A hollow plastic member provided with end caps having holes therein through which wires can pass and be placed under tension so as to provide internal support for the member to reduce deflection of the member when a load is placed thereon and to return the member back within acceptable limits to its original position.

Description:
BACKGROUND OF THE INVENTION 
     Hollow plastic extrusions in the form of tubing or those extrusions which are rectangular in cross section are used for a variety of purposes, but especially for fence rails. Common plastic material used for this purpose is vinyl. When fence rails made from such materials are put under a load at right angles to the fence rail between the ends of the fence rail, the rail can deflect a great deal. 
     BRIEF SUMMARY OF THE INVENTION 
     The purpose of this invention is to prevent such deflection of hollow plastic extruded members, especially those used as fence rails. The hollow extruded member is provided with end caps which have at least two pairs of oppositely disposed holes therein and at least two wires each extending through each of two sets of holes in each end cap and extending the interior length of the fence rail and are then joined together at the outside of one of the end caps and placed under tension when so joined. 
     It is therefore an object of this invention to provide a hollow plastic extrusion with suitable interior wire reinforcing so as to prevent unnecessary deflection in use. This, together with other objects of the invention, will become apparent from the following detailed description of the invention and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1. A perspective view of an extruded plastic rectangular member with the two wires suitably connected together under tension. 
     FIG. 2. A side elevation of the extruded plastic rectangular member. 
     FIG.  3 . An end view of the end of the extruded plastic rectangular member in FIG. 1 where the wires are joined together. 
     FIG. 4. A section through FIG. 2 on the plane  4 — 4 . 
     FIG.  5 . An end view of the opposite end of the extruded plastic rectangular member. 
     FIG. 6. A side view in section of the extruded plastic rectangular member shown in FIG.  1 . 
     FIG.  7 . An extruded plastic member similar to that shown in FIG. 1 only circular in cross section. 
     FIG. 8. A section through FIG. 7 on the plane  8 — 8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings and in particular to FIG. 1,  10  is a typical fence rail provided with end caps  11  and  12 . Each of the end caps has holes near the comers thereof through which the wires are shown extending. The holes in end cap  12  are shown at  12   a ,  12   b ,  12   c  and  12   d . The holes in end cap  11  are shown at  11   a ,  11   b ,  11   c  and  11   d . (See FIG.  5 ). 
     One wire  13  extends through the two holes  11   a  and  11   b  in the end cap  11  (see FIG.  5 ), and through the corresponding two holes  12   a  and  12   b  in the end cap  12  and the two ends of wire  13  are joined together by connector  14  with the wire  13  under tension. Galvanized steel ⅛″ high tension wire has been found to be very satisfactory. Similarly, wire  15  is led through the holes  12   c  and  12   d  in end cap  12  and the corresponding holes  11   c  and  11   d  in end cap  11  and the two ends of wire  15  are joined together by connector  16  with the wire  15  under tension. Also shown in FIG. 2 are the wire  15  and the connector  16 . 
     Referring now to FIG. 5, it will be seen that the wire  15  extends through hole  11   c  in the end cap  11  down along the back of the end cap  11  and back through the hole  11   d  in the end cap  11 . 
     FIG. 3 shows the end cap  12  and the two ends of wire  13  and the two ends of wire  15  being joined together by connectors  14  and  16  respectively after having been placed under tension. 
     In FIG. 4, the wires  13  and  15  are shown traversing the interior length of the fence rail  10  adjacent the four interior comers of the fence rail  10 . 
     FIG. 5 is a view of the cap  11  and it will be seen that wire  13  enters through holes  11   a  and  11   b  in end cap  11  and the wire  15  enters the end cap  11  through holes  11   c  and  11   d  and then both wires return through the interior length of the fence rail  10  to the corresponding holes in end cap  12 . 
     FIG. 6 is a section of the fence rail  10  showing the wire  13  entering holes  11  a and  11   b  in end cap  11 , traversing the length of the interior of the fence rail  10  and exiting end cap  12  through holes  12   a  and  12   b  and being held together under tension by connector  14 . Wire  15  is similarly positioned on the opposite side of fence rail  10 . 
     FIG. 7 shows a variation of the fence rail  10 , namely fence rail  10   a , which is circular in cross section and also provided with end caps provided with corresponding holes and wires  13   a  and  15   a  and connectors  14   a  and  16   a  functioning in the same fashion as is the case with the fence rail  10  shown in FIG.  1 . FIG. 8 is a sectional view of rail  10   a  on the plane of  8 — 8  as shown in FIG. 7 with the two wires  13   a  and  15   a  shown running the interior length of the rail  10   a.    
     By constructing a hollow plastic member which is greater in length than in width with these internal wire supports under tension significant deflection of the member when a load is placed between the ends thereof is avoided and the member will return to within acceptable limits of its original position. 
     EXAMPLE 
     A standard 8 foot length of vinyl fence rail was supported at each end and a 500 lb. weight was placed on the fence rail at its center. The fence rail was distorted several feet and did not return to its original shape. An 8′ long length of vinyl fence rail made in accordance with the present invention was supported at each end and a 500 pound weight was placed at the center thereof. The fence rail was only distorted 5″ and when the weight was removed it recovered to within ½″ of its original position. 
     While this invention has been shown and described with respect to a detailed embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the scope of the claims of the invention.