Abstract:
An electrically insulated fence including a substrate of a rigid wire mesh fence, with a coating or covering there on, rendering the fence electrically isolated, in order to deter electrocution of maintenance workers coming into contact with the electrically charged fence. All surfaces, which may be contacted by the maintenance worker, are preferably either coated or covered with an extruded piece of electrically insulating material.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 60/552,628 filed on Mar. 12, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates to an electrically isolated industrial coated wire mesh fence, and more particularly to an electrically isolated and insulated fence assembly for use in an industrial plant to prevent injuries from electrocution.  
         [0004]     2. Description of the Prior Art  
         [0005]     Conventional perimeter fences are well known in the art, including one of the most common types of coated wire mesh or chain link fences for surrounding operating machinery. However, practitioners of those inventions have become aware of certain problems, which are presented by those prior art inventions. One particular problem that has plagued users has been industrial accidents which may occur in an industrial plant when a worker comes into contact with an electrically charged fence. An electrically charged fence may occur accidentally when an errant live wire comes into contact with a metal fence. This accidental electrification of the fence makes any worker that comes into physical contact with the fence a prime candidate for electrocution.  
         [0006]     Therefore, it would be an advantage to the industry to provide an electrically insulated and isolated fence assembly so that a worker that contacts an accidentally electrified fence assembly would not have a chance to become electrocuted. It would also be desirable, in the industrial plant setting, to have an electrically insulated and isolated fence assembly which is always in an electrically insulated state in order to prevent electrocutions.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with the above-noted advantages and desires of the industry, the present invention provides an electrically insulated and isolated fence assembly which remains insulated and isolated at all times due to its construction. The fence assembly of the present invention essentially includes an electrical isolation jacket to be worn around all of the metal mesh fence sections so that any one who touches the fence is protected from electrocution. The fence assembly may include an extruded fence post and rail design which is thereafter either PVC coated or is adapted to receive any other type of electrically insulating post cover made of any suitable moldable or coatable material, such as a plastic material including thermoplastic or thermoset materials, including but not limited to polypropylene, polyethylene, polyurethane or any other suitable plastic material. Materials having the property of being electrically insulating work well for this application. In the preferred embodiment, including the design of such an extruded cover piece, the cover is combined with the plastic coating or electrically insulating layer covered material to be utilized over the metallic portion of the fence, thereby yielding an electrically insulated and isolated fence assembly which meets or exceeds all of the advantages and desires of the industry.  
         [0008]     Although the invention will be described by way of examples hereinbelow for specific embodiments having certain features, it must also be realized that minor modifications that do not require undo experimentation on the part of the practitioner are covered within the scope and breadth of this invention. Additional advantages and other novel features of the present invention will be set forth in the description that follows and in particular will be apparent to those skilled in the art upon examination or may be learned within the practice of the invention. Therefore, the invention is capable of many other different embodiments and its details are capable of modifications of various aspects which will be obvious to those of ordinary skill in the art all without departing from the spirit of the present invention. Accordingly, the rest of the description will be regarded as illustrative rather than restrictive. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     For a further understanding of the nature and advantages of the expected scope and various embodiments of the present invention, reference shall be made to the following detailed description, and when taken in conjunction with the accompanying drawings, in which like parts are given the same reference numerals, and wherein;  
         [0010]      FIG. 1  is a perspective view of one embodiment of an electrically isolated fence assembly made in accordance with the present inventions;  
         [0011]      FIG. 2  illustrates a perspective cutaway view of one embodiment of the various members detailing the location of the sense receptors;  
         [0012]      FIG. 3  is a perspective view of a corner bracket of the present invention;  
         [0013]      FIG. 4  illustrates a top perspective cross sectional view of the most preferred embodiment of the post;  
         [0014]      FIG. 5  is a top plan view of an electrically insulated post cover made in accordance with the presence invention;  
         [0015]      FIG. 6  illustrates an end cap to be received on top of the post shown in  FIG. 4 ;  
         [0016]      FIG. 7  is yet another embodiment of a post base; and  
         [0017]      FIG. 8  is a side perspective view of another embodiment of the present invention showing an insulated perimeter fence. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]      FIG. 1  illustrates an electrically insulated and isolated fence assembly generally denoted by numeral  10  made in accordance with the present invention, which preferably includes an extruded post  12 , preferably made of aluminum, and also including an insulating cover  14  thereover, where the insulating cover  14  is made of an appropriate electrically insulating material, especially thermoplastic or thermoset materials, and more preferably either an extruded polypropylene or extruded PVC or a mesh that is coated with PVC. However, post  12  may be of any suitable configuration, including a conventional steel tube coated with PVC or the like, so long as it is rendered electrically isolated. Post  12  is preferably capped with an end cap  16  in order to achieve more protection. Post  12  incorporates a design to receive corner brackets  18  which receive frame members  24 . Post  12  is attached to the floor by a post base  20 , which provides rigidity to the fence assembly.  
         [0019]      FIG. 2  illustrates a first embodiment of a frame member, generally denoted by the numeral  24 , which includes an extruded profile  26  and a rib member  28 . In this particular embodiment, one side of frame  24  may include a single rib  28 , while the other side of frame  24  includes multiple ribs  30 . As with any fence, the fence itself is to be received within wire mesh receiver cavity  32 . Wire mesh is not shown in  FIG. 1 , although it is generally accepted that a coated wire mesh fence would be in the middle of the frame member  24 . Further embodiments of the fence may include any commercially available fencing or barrier material, including, but not limited to acrylic sheets, plastic fencing, plywood, or any combination thereof.  
         [0020]     Also extruded into frame member  24  is preferably a fastening cavity  34  for receiving an extruded jacket in order to provide the electrical insulation, which is desired. Although polypropylene is preferred any suitable plastic material may be used. Extruded frame member  24  may also include an optional tang  36  emanating from the circumference of frame member  24 . Tang  36  is useful for other applications, including attachment to the upright post  12 . For ease of manufacturing, a tang may be included on all frame members  24 , and then used for all applications, even though it might not be of any help for the horizontally mounted frame members, as seen in  FIG. 1 .  
         [0021]      FIG. 3  illustrates a useful corner bracket, generally denoted by the numeral  40 , which includes a frame receiver  42  and a tang receiver  44 . Within the circumference of frame receiver  42 , there is preferably a fastening cavity  46  and a strengthening gusset  48 . Although these are optional, they are most preferable for the present applications. Tang  36  shown in  FIG. 2  is received within tang receiver  44  of  FIG. 3 .  
         [0022]      FIG. 4  illustrates a perspective cross-sectional view of the most preferred embodiment of post  12  of  FIG. 1 . This is shown in greater detail, and the post configuration is generally denoted by the numeral  50 , including angular receivers  52  extruded out of the sides of post  12  in order to provide a great deal of adjustability and angles to be made in the fence itself. Angular receivers  52  are shown as being provided in multiplicity to provide multiple options to anyone installing this type of fence, and allowing for many different angles. In the post  50  illustrated in the embodiment shown in  FIG. 4 , there are shown four 90° parallel receivers  54 , and four intermediately angled angular receivers  52 . These receivers, collectively, are designed to receive the tang  36  of the framing members illustrated as element  54  in  FIG. 2 . In practice, the post  12  of  FIG. 1  receives the tang  36  of  FIG. 2  and yields the frame assembly as illustrated in  FIG. 1 .  
         [0023]     Still referring to  FIG. 4 , there is shown a core-out feature  56  in order to remove some of the weight of post  50 . Post cover receivers  58  are illustrated in  FIG. 4  and they are adapted for receiving a plastic cover, and especially adapted for receiving an extruded polypropylene or polyurethane insulating cover as described more fully with reference to  FIG. 5 . Surrounding the post cover receivers  58  are numerous outer post structural supports  60 .  
         [0024]      FIG. 5  illustrates an electrically insulating post cover manufactured in accordance with yet another embodiment of the present invention, and is generally denoted by the numeral  62 . This electrically insulating cover is preferably made of polypropylene, but may be made of any plastic, including thermoplastic or thermoset material. As long as the material is formable, extrudable, or the like, and has a property of being electrically insulating, that material is suitable for this application. Therefore, various ceramics such as alumina, silicone nitride, silicon carbide would also be suitable. Cover  62  includes an outer surface  64  into which cutouts  65  have been made in conjunction with tear-off cutouts  68  on the interior surface such that these sections can be ripped out if the cover is put over a post, such as post  50  in  FIG. 4 , but needs a section to be eliminated in order to allow for an angular receiver  52  to receive tang  36 . This makes the cover  62  completely versatile for many installation angles and applications, and the tear-off cutouts  68  and  65  will allow someone in the field to merely rip off the plastic in a particular area for as long as it is needed to be torn off in order to make it adaptable to receive tangs in their desired configuration. Note also that key fastener  66  projects inwardly from the body of cover  62  and is designed to be received by post cover receiver  58  as illustrated in  FIG. 4 . Key fastener  66  may have many different configurations, any one of which will mate with the post cover receiver  58  and lock therein in order to deter someone from removing the cover and thereby possibly electrocuting themselves.  
         [0025]      FIG. 6  illustrates an end cap, which is generally denoted by the numeral  70 , and which is designed to be received on top of post  50  as illustrated in  FIG. 4 . The interior diameter dimension of end cap  70  is closely mated to the exterior diameter dimension of post  50 , and will slip thereon in order to prevent electrocution. End cap  70  is also made of an electrically insulating material as those described hereinabove, and may be made of polypropylene, polyethylene, polyurethane, or any other suitable plastic or thermoplastic, or any type of ceramic material, or any other suitable material as long as it is electrically insulating.  
         [0026]      FIG. 7  is another embodiment of the post base in accordance with the present invention, and includes a post receiver generally denoted by the numeral  80 . Post receiver  80  includes the post receiving channel  86  and is attached to post receiving base  88  by strengthened brace gussets  82 . Apertures  84  in drilled-through base  88  allow for adjustable and easy installation onto the floor of a shop in order to receive the electrically isolated fence.  
         [0027]     Finally, we now look at  FIG. 8 , an insulated perimeter fence in accordance with another embodiment of the present invention and is generally denoted by the numeral  100 . A coated wire mesh fence, such as this shown coated wire mesh fence  102  is installed between two upright posts  104  as shown in this illustration. Posts  104  are held within post bases  106 , acting as receivers for an electrically insulated frame member  108  that holds and secures the coated wire mesh fence  102 . Clearly, coated wire mesh fence  102  may be of any suitable configuration for the application, as long as it is electrically insulating. Preferably, coated wire mesh fence  102  is a wire mesh fencing material made of interlocking metal wire and is preferably dipped into an electrically insulating material, preferably a PVC solution, thereby coating the metal and rendering the fence itself electrically insulating. Thereafter, these sections may be slid into receivers within frame  108  as disclosed with regard to  FIGS. 1 through 4  above. The tangs of frame member  108  (not shown here) are received within post  104  and secured therein. Referring back to  FIG. 2 , the mesh screen receiver  32  of the frame members  24 , act as receivers for the coated wire mesh fence  102 .  
         [0028]     In summary, numerous benefits have been described which result from employing any or all of the concepts and the features of the various specific embodiments of the present invention, or those that are within the scope of the invention. The electrically insulated fence acts as a protective measure for maintenance workers.  
         [0029]     The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims which are appended hereto.  
       INDUSTRIAL APPLICABILITY  
       [0030]     This invention finds particular utilities in the manufacturing art, and is especially used for perimeter fencing used around dangerous manufacturing machines.