Abstract:
The railing section includes an integral component defining an upper rail, a lower rail and a series of spindles or balusters or other screening or blocking structure therebetween which forms a structural connection between said rails. These components are interconnected by hollow cavities which can receive a reinforcing material. The railing section is preferrably made by blow molding and the upper and lower rails can receive structural members interior to the rails to improve the strength of the railing section.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to railing sections and in particular, to a blow molded railing section.  
         BACKGROUND OF THE INVENTION  
         [0002]    There are a number of different plastic and metal systems that have a series of different parts which are fastened together to form a railing section. In particular, there are a number of plastic railing systems where the top rail and bottom rail, as well as the various spindles or balusters, are each independently manufactured, using an extrusion, blow molding or injection molding technique, and the components are then modified to simplify the mechanical securement of the individual parts.  
           [0003]    With these systems, there is a very significant labor component associated with the fabricating of the final product either by the end consumer or by manufacturer.  
           [0004]    The present invention overcomes a number of disadvantages of the above prior art systems and is cost effective to manufacture.  
         SUMMARY OF THE INVENTION  
         [0005]    A railing section for securement between upright members according to the present invention comprises a hollow upper rail, a hollow bottom rail and a series of hollow spindles or balusters integrally connected to said top and bottom rails, and wherein the railing section is made of a plastic material as a single integral structural.  
           [0006]    According to an aspect of the invention the hollow spindles or balusters are connected to the hollow upper and hollow bottom rails such that hollow cavities thereof are interconnected.  
           [0007]    In a further aspect of the invention the hollow upper rail is open at least one end thereof and a reinforcing member is inserted in and runs the length of said upper rail.  
           [0008]    In yet a further aspect of the invention the hollow bottom rail is open at least one end thereof and a separate reinforcing member is inserted in said open end and runs the length of said bottom rail.  
           [0009]    According to an aspect of the invention the upper rail forms the finished hand rail of said railing section.  
           [0010]    According to a further aspect of the invention the upper rail and the bottom rail are of similar cross section.  
           [0011]    In yet a further aspect of the invention the rail section is made by blow molding.  
           [0012]    In a preferred aspect of the invention the railing section is of a length that completes at least a five foot section between post centers in the final installation.  
           [0013]    In a further aspect of the invention the upper rail and the bottom rail are angled relative to the spindles to provide a railing section suitable for use with a ramp or stairs.  
           [0014]    A blow molded railing section according to the present invention comprises a hollow upper rail and a hollow lower rail integrally connected by a blocking structure which maintains the spacing of said rails and transfers loads therebetween, and wherein said railing section is made of a plastic material and is blow molded as a single component.  
           [0015]    According to an aspect of the invention the blocking structure of the blow molded railing section includes a series of hollow cavities which are interconnected to hollow cavities of said upper rail and said lower rail.  
           [0016]    In yet a further aspect of the invention the blocking structure is a series of parallel hollow spindles.  
           [0017]    In a preferred aspect of the invention the blow molded railing section is of a length of at least five feet.  
           [0018]    In yet a further aspect of the invention the upper rail has an elongate central cavity running the length thereof and receives interior to said upper rail an elongate reinforcing member.  
           [0019]    In yet a further aspect of the invention the lower rail has an elongate central cavity running the length thereof for receiving interior to said lower rail an elongate reinforcing member.  
           [0020]    A railing system according to the invention comprises a series of spaced uprights with a series of blow molded railing sections closing the space between said uprights, each railing section comprising a hollow upper rail and a hollow lower rail integrally connected by a blocking structure which maintains the spacing of said rails and transfers loads therebetween, and wherein said railing section is of a plastic material and is blow molded as a single component.  
           [0021]    The railing system according to an aspect of the invention has each blow molded railing section secured to adjacent uprights by means of connectors attached to said uprights. It is also possible to secure the railing section by providing ports in the uprights sized to accept the railing sections.  
           [0022]    In yet a further aspect of the invention the upper rail and the lower rail of each section includes reinforcement to improve the structural characteristics of said rails within hollow cavities of said rails. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    Preferred embodiments of the invention are shown in the drawings, wherein:  
         [0024]    [0024]FIG. 1 is a partial perspective view illustrating the blow mold process;  
         [0025]    [0025]FIG. 2 is a sectional view showing the blow mold in process;  
         [0026]    [0026]FIG. 3 is a perspective view of the one piece railing section;  
         [0027]    [0027]FIG. 4 is a partial exploded perspective view of the railing system;  
         [0028]    [0028]FIG. 5 is a partial side view showing fastening of the railing section to a post; and  
         [0029]    [0029]FIG. 6 is a side view of a railing section suitable for stairs. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    The blow molding arrangement  2  as shown in FIG. 1 comprises an extruder  4  which extrudes an envelope (parison)  6  of extruded plastic which is located between the opposed mold blocks  8 . The open interior of the envelope of plastic is under pressure and this pressure serves to blow the envelope against the exterior walls of the cavities of the mold blocks. This is more clearly illustrated in the sectional view of FIG. 2 where the mold blocks are in engagement and define an interior cavity the shape of the desired finished product. In this case, the cavity is shaped to form the railing section  20 .  
         [0031]    The railing section  20  as shown in FIG. 3 includes a top rail  22 , a bottom rail  24  and a series of spindles  26 . The railing section  20  can be of different lengths and is preferrably of a length of at least five feet and there are many applications where the preferred length is approximately eight feet or greater. A length suitable for securement between uprights on six foot centers is popular and can be easily stored for warehousing on a 4 by 6 foot pallet. The railing section preferrably is a single integrally molded plastic component. Typically when this product is taken out of the mold blocks  8 , there is some flashing which must be removed. In particular, there will be flashing between the spindles and flashing at the ends of the top rail and the bottom rail. These can be trimmed with a knife, router or by a press to provide the desired finished surface.  
         [0032]    To assist the product in separating from the mold blocks, there is approximately a five degree draft on the various surfaces, thus the components are not perfectly square and have a slight inward taper toward the outside edges of the product.  
         [0033]    In many cases, it will be necessary to add additional reinforcing during the final installation of the product. As shown in FIG. 4, a top metal channel insert  30  is inserted in the upper rail  22  and similarly, a channel reinforcing member  32  is inserted in the interior of the lower rail  24 . These reinforcing members preferrably extend and overlap with the connectors  34 . It can be appreciated that other arrangements for reinforcing of the railing section  20  can be carried out.  
         [0034]    For example, the reinforcing member could be made of wood such as a 2 by 3 of appropriate length, or other arrangements for reinforcement of the rail members can be used. Such other methods could include providing structural foam in the upper and lower rails to provide additional strength and reinforcing and or the insertion of any suitable structural member.  
         [0035]    As can be appreciated from FIG. 4, the railing section  20  is secured between upright posts  40  often on six foot centers. Preferrably, these posts are made of wood and include a plastic post cover  42  which is also blow molded and merely slides over the four by four post. Basically the blow molded covers are open at the bottom and have a finished top surface. The post covers are cut to the appropriate length on site. In this way, a finished outer surface is provided to the wooden post  40  and the finish of the post cover corresponds to the finish surface of the railing section. Once the post covers have been positioned, the connectors are secured to the posts with the screws of the connector passing through the post cover and engaging the wooden post as shown in FIG. 5.  
         [0036]    Another method of securing without connectors includes providing recesses in the uprights sized to accept the top and bottom rails of the railing section.  
         [0037]    It is also desirable to mechanically fasten the railing section to the connectors. This mechanical fastening could include a direct connection as shown in FIG. 5 or could include merely a pressed fit type connection which additionally accommodates expansion and contraction of the railing section.  
         [0038]    A modified railing section  21  is shown in FIG. 6 and is used for stairs or ramps. The railing section can be cut to the appropriate length and secured between an upper and a lower post. Preferrably the upper rail section and the lower rail section are of the same design. As such, the connector for the upper rail and the lower rail can be the same on the upper post and similarly, the same connector can be used on the upper rail and the lower rail at the down post. In this way, the number of components, and in particular, the number of connectors necessary for the angled railing is reduced. If the railing is made on a forty five degree angle, a single connector can be used for both upper posts and lower posts. As can be appreciated some variation in the angle can be accommodated by the connector.  
         [0039]    The railing section has been described as a blow molded component where the upper rail and the lower rail are of a similar cross section. This design reduces the number of connectors necessary to secure the railing system.  
         [0040]    In some cases it may be desirable to have a more ornate handrail and if desired this can be blow molded with the blocking structure but as a component which will eventually be separated from the blow molded blocking structure. It is also possible to extrude a handrail of the desired shape and snap it over the upper rail. This arrangement allows a reduced number of connectors and also allows more detailed handrails. It can further be appreciated that the reduction in manufacturing costs is primarily due to the blow molding of the spindles or blocking structure between the upper and lower rails as a connected component. Therefore if desired specialized handrails and bottom rails made by extrusion or blow molding can be use in combination with the blow molded blocking structure. The blocking structure can also be designed to be joined with the joint hidden by the subsequently applied handrail and lower rail. This is particularly suitable for spindle blocking members as the joint can occur between spindles. The blow molding of the blocking structure simplifies the system, provides the capability to have good depth of the blow molded component and provides a system which is cost effective to manufacture.  
         [0041]    Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.