Patent Document

The present application is a continuation of U.S. patent application Ser. No. 12/584,864, Cable Support System, which was filed on Sep. 14, 2009, and which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The technical field of the invention is that of racks for supporting power and communication cables in underground manholes, vaults, and tunnels. 
     BACKGROUND 
     Cable supports are used to organize and support medium voltage power distribution cables in underground manholes, vaults, and tunnels. Cable supports are also used to organize and support underground low voltage power cables and control cables, high voltage power transmission cables, and communication cables. Cable supports may also be used above ground and in areas other than underground manholes, vaults and tunnels. 
     These cables for electric power, control and communication lines are run underground in order to protect them from above-ground elements and from the interference and damage they would suffer when installed above the ground or on poles or structures. The underground environment may be less hostile in some ways, but the history of underground cables suggests that the underground environment is not benign. The environment in underground power and communications manholes is indeed harsh. 
     While there may be fewer ultraviolet rays and less severe weather underground, and the temperature is more constant, moisture and humidity are always present. There are other considerations, such as the constant and higher danger from flooding, and underground pests that consider electrical insulation, and even steel, a tasty treat. Manholes may fill with water that is often contaminated with sewage, fertilizer runoff, tree roots, and chemicals, including caustic materials. Very harsh sea or salt water sometimes fills manholes. Many manholes are completely or partially filled with such contaminated water all of the time, except when pumped out for maintenance. Others fill periodically but are hot and have extremely high humidity, while still others fill and empty with ocean tides. 
     As noted, most power and communications manholes are partially or completely full of water some of the time or all of the time. The amount of water in a given manhole is influenced by location, surrounding conditions, drainage, and weather. Manholes located at higher grades generally will be filled with less water for a shorter period of time than those located at lower grades. Manholes located where the surrounding area has a high ground water level and/or a high amount of rain generally are filled with water to a higher level and more of the time than those located in areas that have a low surrounding ground water level and/or a low amount of rain. The water level in manholes located close to the ocean often changes with the tide, and the constantly-changing interface only increases the likelihood for corrosion. The condition of water in underground power and communications manholes occasionally is fresh and clean but most often is contaminated, as noted above, or is salt water, both of which can be very corrosive and also conductive. 
     Communication and power cables should be kept off surfaces, such as a floor or the ground, and should be organized and protected to the greatest extent possible. Cables are thus typically supported underground by racks that elevate cabling and keep the cabling off the ground, thus shielding the cables from at least some of the worst underground dangers. Racks for supporting cables must be able to withstand both heat and cold, all conceivable temperatures and humidities in every combination. In addition, the racks must be able to support very heavy loads from power and communication cables. The racks themselves are preferably supported, e.g., attached to a wall, rather than free-standing structures. Thus, the racks will have penetrations, or stress concentrators, to deal with, in these hot, humid, and stressful environments, along with the high loads expected from supporting cabling. The walls themselves may have penetrations for supporting bolts, pins or other fasteners used to secure the racks in place. The walls, such as concrete walls or other structures, will also be in intimate contact with the racks, adding their chemical potential for corrosion to the racks. 
     All these stresses combine to make the underground a challenging environment for cable racks. For the most part, existing cable supports used in underground manholes, vaults, and tunnels are manufactured using steel stampings, steel forms, or steel weldments. They may also be ductile iron castings. After the supports are stamped, formed, welded, or cast, they are hot dip galvanized in an effort to prevent corrosive deterioration. The steel arms and posts are bonded together and grounded in an attempt to prevent corrosion. Eventually, the galvanized coating is consumed and the steel racks may oxidize or corrode away, leaving the power and communications cables without support. 
     Two phenomena, galvanic corrosion and stray current corrosion, occur in flooded underground manholes to cause this deterioration. Galvanized steel cable supports are very vulnerable to both galvanic and stray current corrosion and often become severely corroded to a point that they will no longer support the cables in a very short period of time. 
     Galvanic corrosion is an electrochemical process in which one metal, the anode, corrodes preferentially when in electrical contact with a different type of metal, the cathode, and both metals are immersed in an electrolyte. In flooded underground power and communications manholes the galvanized steel cable supports are the anodic sites of the galvanic corrosion reaction. Cathodic parts in the manhole, parts made from more noble metals such as stainless steel, may be damaged in the galvanic corrosion process due to generation of electrolytic hydrogen on their surfaces causing hydrogen embrittlement. Stray current corrosion of underground power and communication cable supports is usually caused by power and communications manholes being located in the vicinity of electric rail tracks, pipe lines that are cathodicly protected or the like. 
     Underground galvanized steel cable supports that are severely corroded and can no longer support the cables result in power and communications interruptions and a safety hazard to technicians who enter the manhole. Another safety issue is that galvanized steel cable supports are conductive. If a power cable&#39;s insulation is compromised and the electrified conductor contacts a galvanized steel cable support, the cable support is energized. If a technician inadvertently touches the energized cable support he may be electrocuted. 
     What is needed are safer cable racks better able to withstand the environment and better able to tailor themselves to a greater variety of situations, for fewer stresses, and for longer service. 
     BRIEF SUMMARY 
     One embodiment is a method of supporting power and communication cables. The method includes a step of furnishing a nonmetallic cable arm support stanchion, the stanchion comprising a cross section selected from the group consisting of an E-shape and a C-shape. The method also includes steps of attaching a nonmetallic cable rack arm to the nonmetallic cable arm support stanchion and placing at least one power or communication cable atop the cable rack arm, wherein the cable rack arm and flanges of the nonmetallic stanchion face in a same direction. 
     Another embodiment is a method of supporting power and communication cables. The method includes steps of furnishing a nonmetallic cable arm support stanchion, the stanchion including a cross section selected from the group consisting of an E-shape and a C-shape, attaching a cable rack arm having an interface to the nonmetallic cable arm support stanchion, wherein the interface includes a top relief allowing upward rotation of the cable rack arm from a horizontal position when mounted to the stanchion. The method also includes placing at least one power or communication cable atop the cable rack arm. 
     Another embodiment is a nonmetallic support stanchion. The nonmetallic support stanchion includes a nonmetallic web having a rectangular cross section, and at least two nonmetallic parallel flanges perpendicular to the web and joined to the web and forming corners with the web, wherein the stanchion comprises at least one layer of glass fiber reinforcement perpendicular plus or minus 15 degrees to a length of the stanchion, wherein the flanges further comprise at least two orifices penetrating the flanges for mounting a nonmetallic cable rack arm and wherein the web further comprises at least one orifice penetrating the web for attaching the nonmetallic support stanchion to a formation selected from the group consisting of a wall, a column, a structure or a surface. 
     Another embodiment is a nonmetallic support stanchion. The nonmetallic support stanchion includes a nonmetallic web having a rectangular cross section, at least two nonmetallic flanges perpendicular to the web and joined to outer edges of the web and forming corners with the web, wherein the stanchion further comprises at least one first layer of glass fiber reinforcement perpendicular plus or minus 15 degrees to a length of the stanchion and a second layer of glass fiber reinforcement perpendicular to the at least one first layer of glass reinforcement, and a resin filling voids within the stanchion. 
     There are many other aspects of the invention, of which a few are described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of stanchions with cable rack arms in a typical underground installation with embodiments of the present invention. 
         FIG. 2  is a closer perspective view of some of the embodiments of  FIG. 1 . 
         FIG. 3  is an exploded view of the embodiment of  FIG. 2 . 
         FIG. 4  is a bottom perspective view of the arm of  FIG. 2 . 
         FIG. 5  is a partial cross-sectional side view of the arm of  FIG. 4  in a deployed position and  FIG. 5A  is a close-up perspective view depicting the top relief. 
         FIG. 6  is a partial cross-sectional side view of the arm of  FIG. 4  in a raised position and  FIG. 6A  is a close-up perspective view depicting how the top relief allows the raising. 
         FIG. 7  is a perspective view of a single flange and rectangular bar steel stanchion, hereinafter referred to as a single flange stanchion. 
         FIGS. 8 and 9  depict a bottom partial cross-sectional view of the single flange stanchion of  FIG. 7  with an embodiment of the present cable rack arm. 
         FIG. 10  depicts a channel stanchion with a cross-section shape in the form of a C, that is, a C-channel stanchion. 
         FIG. 11  depicts the C-channel stanchion of  FIG. 10  with embodiments of the cable rack arm mounted to the stanchion. 
         FIGS. 12 and 13  depict partial cross-sectional side views of the embodiment of  FIG. 11 . 
         FIGS. 14 and 15  depict partial cross-sectional bottom views of the embodiment of  FIG. 11 . 
         FIGS. 16-18  depict perspective views, respectively, of cable rack arm embodiments mounted on an E-structural shape or E-channel stanchion, a TEE-bar stanchion and an L-angle stanchion. 
         FIG. 19  is a top view of a fiberglass cross layered knitted apertured mat. 
         FIG. 19A  is a closer detail view of the embodiments in  FIG. 19 . 
         FIG. 20  is a bottom view of the embodiment of  FIG. 19 . 
         FIG. 20A  is a closer detail view of the embodiment of  FIG. 20 . 
         FIG. 21  is a cross-sectional view of a non-metallic C-channel stanchion. 
         FIG. 21A  is a closer view of the embodiment of  FIG. 21   
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the cable arm described herein are preferably molded from plastic materials. In this context, “plastic” materials include any resinous, thermoset, or thermoplastic materials, including materials that are reinforced or otherwise altered, and which are formed by molding. Thus, in one embodiment, nylon with short glass fibers is used to make strong, stiff, and environmentally-resistant rack arms. In the present context, short glass fibers intends glass fibers from about ⅛″ (about 3 mm) long to about ¼″ (about 6 mm) long. Long glass fibers, from about 3/16″ (about 5 mm) to about ⅜″ (about 10 mm) may be used instead. Other embodiments may use less costly materials, such as polyethylene or polypropylene, for applications in which not as much strength is required. The plastic materials may also include particulate fillers, such as aluminum oxide or calcium carbonate, or any other filler useful in plastics molding. Glass fibers with diameters from about 0.009 mm (0.00035 in) to about 0.011 mm (0.00043 in) may be used for reinforcement. Fibers with other diameters may also be used. 
     In addition to cable arms, the stanchions may also be molded from non-metallic materials. Stanchions may be injection molded, thermoformed, transfer molded, compression molded, or even pultruded. Typical polymers or resins include polyester, such as standard polyester, fire-retardant polyester, vinyl ester and fire-retardant vinyl ester. In addition to a thermoplastic or thermoset resin, the stanchions may include a reinforcement, such as glass fibers. Parts that are discretely molded, one at a time, may include chopped or short glass fibers, as mentioned above. These parts or parts that are pultruded may also be made with unidirectional fiberglass roving, continuous strand multidirectional glass fiber mat and stitched woven fiberglass roving. The reinforcements add longitudinal and transverse strength and stiffness. An outer surface veil mat may also be used to add UV resistance and hand-friendliness to the resin-rich surface. If greater strength or stiffness is desired, carbon fiber reinforcement may also be used in addition to or in lieu of glass. 
     In one embodiment, pultruded C-channels are made with about from about 30 to about 40 weight %, e.g., 33%, unidirectional fiberglass roving and about 10 to about 25 weight %, e.g., 17%, continuous multidirectional glass fiber mat. Higher or lower loadings of reinforcement may be used. The mat is believed to especially increase the strength and stiffness of the corners of the pultrusion. In other embodiments, unidirectional roving is stitched together with transverse glass or cotton fibers to form a stitched woven fiberglass roving. The stitching helps to orient and control the roving and make it easier to pull into the tooling. The proportion of the reinforcements may vary within reasonable limits consistent with the desired strength and stiffness, e.g., from about 35% to 65%, or even higher. In other embodiments, only the continuous multidirectional glass fiber mat may be used. In still other embodiments, other forms and orientations of reinforcement may be used. All are intended to be within the scope of the present disclosure. A few specific embodiments are discussed below with reference to  FIGS. 19-21A . 
     The pins used to mount the cable rack arms to stanchions may also be molded from plastic materials. The pins are desirably injection molded, but they may also be compression molded, pultruded and/or machined. It will be clear to those with ordinary skill in the art that the pins support a shear load caused by the cable rack arm and the cables loaded onto the arm. Accordingly, reinforcements, such as glass fibers, that are longitudinally oriented will be helpful in supporting the load and resisting deformation. This may be achieved by using glass-reinforced plastic materials. The desired orientation may also be achieved by using wider gates in injection molding the pins. It has also been found during experiments that molding the pin with a reservoir, attached to the end of the pin opposite the gate with a small orifice, causes additional plastic flow and helps to orient the fibers during the injection molding process. 
     Underground cable racks face several constraints for successful service. One of these constraints is that the stanchions or posts generally include penetrations in both the stanchions and the arms so that the stanchions or posts may be attached to the walls or surfaces of the manholes or other underground installations in which they are placed. If cable rack arms are not integral with the stanchions, there are then more penetrations so that the rack arms may be installed, to hold cables for power or communications. Each such penetration may be considered as a stress concentrator, a point in the structure at which stresses will be more likely to cause failure. 
     In molded posts or stanchions, the effects of the stress concentrators may at least be minimized by molding in the penetrations or holes, so that the well-known “skin-effect” of plastic materials will apply, lessening the effect of the stress concentration. The skin-effect of as-molded plastics means simply that there is a barrier layer of resin on the surface, resistant to infiltration of water and other contaminants. Embodiments of the present invention mold in a number of important features to take advantage of the skin effect and to make the stanchions as useful as possible. 
     Embodiments are depicted in  FIG. 1 , which depicts an underground cable installation  10  with two stanchions  12 ,  14  secured to concrete wall  18  via bolts  16  (not all bolts visible in  FIG. 1 ). The stanchions may be existing metallic stanchions, such as single flange steel stanchion  12 . Alternatively, the stanchions may be non-metallic, such as non-metallic C-channel stanchion  14 . In this instance, stanchion  12  is used to mount two cable rack arms  20  and three cable rack arms  30 . Cable rack arms  20  have two position places or saddles on the top portion of the rack arm for mounting power or communications cables  19 . Cable rack arms  30  each have three position places or saddles on top for mounting the cables. Of course, other embodiments may have only a single mount or may have additional mounts, such as an arm with four or five mounts or saddles. Further, some applications may require that the top surface of the arm be flat. One advantage of the embodiments depicted herein is that the mounts or saddles are formed integrally with the rack arms themselves. Thus, no adapters or additional parts need to be assembled before installing and using the rack arms. As noted, the pins  21  may also be made of plastic material. 
     As also shown in  FIG. 1 , stanchion  14  is used to mount two cable rack arms  20  and three cable rack arms  30 . The cable rack arms  20 ,  30  used for stanchion  12  are the same cable rack arms  20 ,  30  used for stanchion  14 . The cable rack arms are adapted for use with both types of stanchions because they include an interface or mounting adapter portion designed for such multi-stanchion mounting. Thus, the cable racks arms described herein are suitable for use in existing facilities with single flange steel stanchions. The single flange steel stanchions have a protruding plane of material that fits into a hollow or interface of the cable rack arm. The cable rack arms are also suitable for use with C-channel-type stanchions, which do not have a flange that protrudes into the cable rack arm. The cable rack arms in these applications mount between the channel flanges, which provide mounting holes for the pins that support the arms. The stanchions may be metallic, e.g., steel, or may be made from newer, non- metallic materials. The cable rack arms are mounted with pins  21  that are secured with cotter pins  23 . 
     A closer perspective view of the installation is depicted in  FIG. 2 , showing cable rack arms  30 . Rack arm  30 , on the left, mounted to wall  18  via double-flanged stanchion  12  and wall mount portions  13 , which wall mount portions include holes (not shown) for mounting bolts  16  and washers  17 . Stanchion  12  itself protrudes into a slot in the back or interface portion of the rack arm, as explained below. An identical rack arm  30 , shown on the right portion of  FIG. 2 , is mounted to channel stanchion  14 , which is also bolted to wall  18  in a manner similar to stanchion  12 . Channel stanchion  14  has a C-shaped cross section formed by web  14   a  and flanges  14   b  on either side of web  14   a . Rack arm  30  on the right is mounted to channel stanchion  14  via mounting pin  21 , secured with cotter pin  23 . The back or interface portion of both rack arms  30  include mounting holes or orifices for mounting pin  21  so the pin can secure the rack arms to the either of stanchions  12  or  14 . 
     The exploded view of  FIG. 3  provides details of the configuration of identical mount arms  30 , enabling mounting to two very different stanchions. Cable rack arms  30  each have an upper portion  32  and a lower portion  38 , the upper and lower portions acting as flanges that are connected via central web  31 . The cable rack arm thus has a cross section with a web and flanges, akin to an I-beam or an H-beam, and has increased section modulus and strength. This increased stiffness or strength makes cable installations more stable and reliable. Upper portion  32  in this embodiment includes three cable rack saddles or mounts  34 , the mounts separated by upper flat surfaces  36 . Lower portion  38 , further described below, is mounted at an acute angle A, less than 90°, and desirably less than 60°, to upper portion  32 . The imaginary apex of the angle will be to the left of the mount arms, as also shown in  FIG. 3 . In practice, angle A may range from about 10 degrees to about 50 degrees, and desirably from about 15 degrees to about 47 degrees. 
       FIG. 3  also depicts the proximal portion  35  of the rack arms, the proximal portion being the end for use near the stanchion. The distal portion  40  is the end of the arm away from the stanchion. The proximal portion includes a rear surface  37 , a portion of which is flat and may be formed at an obtuse angle B to flats on the top portion, an obtuse angle being an angle greater than 90°. The obtuse angle of these flats on the rear or proximal surface prevents downward rotation of arm  30  past the point where the material of the rear surface meets the inner surface of the channel  14 . The obtuse angle B in one embodiment is about 91.5 degrees and may range from about 90.5 degrees to about 95 degrees in practice, although other angles may be used, such as a right angle or an acute angle. Having angle B at 91.5° results in the flats  36  and the saddles  34  having an upward tilt of 1.5°. This upward tilt compensates for the deformation of the arm when it is under load by very heavy power and communication cables. Thus, rack arm  30  will be biased to some extent for upward tilting of the rack arm on its distal end, near angle A. In other embodiments, it may be desirable for the rack arm top surface  36  and saddles  34  to be at a nominal angle different from horizontal (90°). Thus, other embodiments may include cable rack arms designed for an orientation of 30°, 45°, 60° or other angle from horizontal. These angles may be useful for maintenance of the cable after installation. 
     Proximal portion  35  also includes slot  41 , separating the proximal portion into two halves. Slot  41  provides space that allows cable rack arm  30  to accommodate double-flanged stanchion  12  for easy mounting. The halves on either side of slot  41  each includes a mounting hole  39 . The holes thus allow insertion of a pin, such as pin  21 , and its securing cotter pin  23 , through mounting holes  25  of the stanchions  12 ,  14 , as well as the cable rack arm  30  itself. Horizontal mounting holes  39  in this embodiment are below the top surface of the rack arm  30 . In other embodiments, the mounting holes  39  of interface  35  may be molded above the top surface  36 . In yet other embodiments, mounting holes  39  may be molded such that the center of the horizontal orifices  39  are above the top surface  36  of upper portion  32 . The mounting holes  39  are used in all types of stanchions, while the slot  41  is needed only in a double-flange steel stanchion, a TEE-bar stanchion, an L-angle stanchion and an E-channel stanchion, but not a C-channel stanchion. The E-channel stanchion, TEE-bar stanchion and L-angle stanchion are shown in  FIGS. 16 ,  17  and  18  respectively and are described in more detail below. 
     The single flange steel stanchion  12  is well-established in the industry, and the cable rack arms depicted herein include a slot  41 , thus enabling retrofit of the cable rack arms depicted herein to replace older cable rack arms. The cable rack arm embodiments described herein can be used for existing single flange steel stanchions as described and may also be used for new non-metallic C-channel, L-angle, TEE-bar or E-channel stanchions. Each slot  41  or interface also includes a void or relief  49 , the relief in the shape of about a 45 degree angle to the top of the rack arm. Thus, in one embodiment, the interface includes contiguous mounting holes  39 , slot  41  and relief  49 . When the arm  30  is attached to a single flanged stanchion, a TEE-angle stanchion, an L-angle stanchion, or an E-channel stanchion, relief  49  allows upward rotation of the rack arms from their deployed horizontal position as depicted in  FIGS. 2-3 . 
     In other embodiments, the angle between the top surface and the rear or side may be close to 90°, that is, a right angle. In these embodiments, the cable rack arm may be viewed as a three-dimensional right triangle, with the long side or hypotenuse being the angled side on the bottom, that is, the bottom or lower portion. The top or longer portion is the major cathetus of the triangle and the side or shorter portion forms the minor cathetus of the triangle. The sides of the triangle may be connected by a web, a web with ribs, or a gusset. In this patent, the terms major cathetus and minor cathetus intend the top and side of a cable rack arm, whether or not the angle between them is a right angle. 
     A closer, bottom view of the cable rack arm  30  is depicted in  FIG. 4 . Cable rack arm  30  and lower portion  38  includes a proximal portion  35 , for placement nearer the mounting stanchion and a distal portion  40 , for placement away from the stanchion. As noted above, slot  41  separates the proximal portion  35  and rear surface  37  into left and right halves  37   a ,  37   b  and allows insertion of the rectangular bar portion of a single flange stanchion into the slot. In  FIG. 4 , rhomboid sections  37   c  and  37   d  may be molded flat to fit snugly against C-channel, TEE bar, L-angle and E-channel stanchions on which the cable arm is mounted. These are the flat sections discussed above that may be oriented from about 90.5 to 95 degrees to the plane of the top surface of the cable arm. In addition, the cable arm may include two bottom flat portions  37   e  and  37   f  that are about 91° from surfaces  37   c ,  37   d.    
     Flats  37   e ,  37   f  may be oriented at about 1° more than a right angle from surfaces  37   c ,  37   d  as a convenience in removal of the arm from the mold used for manufacturing. 1° is a conventional draft angle. Further, since surfaces  37   e ,  37   f  have 1° taper it is possible to mold rounds  37   h  on the same core pull as slot  41 . Other functions that surfaces  37   e ,  37   f  permit include reducing the arm profile, resulting in less part weight. Slot  41  is extended on both sides by additional side reliefs  43   a ,  43   b  adjacent the left and right halves. Side reliefs  43   a ,  43   b  allow use of the adjustable cable rack arms in existing single flange stanchions having substantial weld formations that would otherwise interfere with their installation. The lower or bottom portion  38  of the cable rack arm is narrower than upper portion  32 , especially near the distal end  40 . 
     Downward rotation of the arm  30  is stopped by surfaces  37   c ,  37   d , heel stops, when the arm is attached to a C-channel stanchion. When arm  30  is attached to a single flange stanchion, downward rotation is stopped when surface  37   g , a slot stop, contacts the front-most face of the single flange stanchion. Consider now the L-angle, TEE-Bar and E-channel stanchions. The L-angle, TEE-bar, or E-channel stanchion may have no nearby bolt heads and washers for attaching the stanchion to the concrete wall, and thus there may be no bolt heads or washers between the arm and the stanchion. In this case, either or both surfaces  37   c ,  37   d , heel stops, as well as surface  37   g , the slot stop, may be used to stop downward arm rotation. Of course, in the case of the L-angle stanchion, either or both  37   c  and  37   g , or  37   d  and  37   g , could be used to stop the downward rotation of the arm since there is only one leg on the L-angle stanchion for surface  37   c  or  37   d  to contact. If the L-angle, TEE-bar or E-channel stanchion has a nearby bolt head and washer for attaching the stanchion to the wall, then only slot stop  37   g  is used to stop downward rotation of the arm. 
     On a side note, there are two types of single flange steel stanchions in wide use. One is fabricated by welding two flanges to a perpendicular bar as shown in  FIG. 7 . The second single flange stanchion is made from a single bar and flanges are formed by twisting 90° approximately the last  3 ″ on both ends of the bar. The single flange stanchion is in wide use and is only made from steel. The L-angle, TEE-bar, E-channel and C-channel stanchions described herein are only nonmetallic and only made using the pultrusion process. These could possibly be made by transfer molding or compression molding or even the RIM molding process, but this has not been done to our knowledge. To date there has been limited deployment of L-angle and TEE-bar nonmetallic stanchions. The assignee of the present patent has just started to manufacture C-channel nonmetallic stanchions. There is no prior art of any kind for the E- channel nonmetallic stanchion. This stanchion has advantages of increased stability and support from the extra, middle flange. 
     Those having skill in the art will recognize that the upper portion  32 , with one or more cable mounts or saddles  34 , needs to be somewhat wider in order to mount the cables. The load is supported by the web  31  and ribs  33  and is transferred to the stanchion. Bottom  38  portion needs only to transfer a part of the load through its length to the stanchion and does not need to be wide, it simply must be thick enough to resist buckling. As better seen in  FIGS. 1-3 , ribs  33  need not be perpendicular to the top or bottom portion, although they may be. In these embodiments, the ribs are from about 30° to about 60° to the top or bottom portions. It will be recognized that the web  31  acts more or less as a gusset, that is, as a reinforcement supporting the top portion and transferring the load on top to the side portion and then to the stanchion. Thus, a gusset, even a plain gusset without ribs, may be used with a top portion, a side portion and an interface to support cables in other embodiments. In some embodiments, a flanged gusset is used. 
       FIGS. 5 and 5A  depict the deployed or horizontal position of the cable rack arm mounted to a stanchion. In the partial cross-sectional view of  FIG. 5 ,  3 -saddle cable rack arm  30  has been pinned to a single flange stanchion  12  with pin  21  through the orifices described above. Stanchion  12  is mounted to concrete wall  18  via wall mounts  13 , anchors  28  and bolts  16 . Cable-tie orifices or holes  45  are visible in cable rack arm  30  in this cross-sectional view. In  FIG. 5 , top relief  49  is visible as an angled gap between the metal of stanchion  12  and the top of the cable rack arm. The close-up perspective view of  FIG. 5A  depicts, as a user would see it, gap or relief  49  in the top of the cable rack arm  30 . 
     The partial cross-sectional view of  FIG. 6  depicts the elements of  FIG. 5  with the cable arm  30  rotated upward. As seen in close-up perspective view  FIG. 6A , arm  30  has rotated sufficiently to close the gap, and the top of the arm  30  is now in contact with stanchion  12 , preventing further upward rotation. Prior art cable rack arms do not have such a relief and do not allow upward rotation. Upward rotation is desirable for two reasons. In particular when retrofitting, it is advantageous to have moveable arms since older cables may have become relatively inflexible over time. Such rotation allows an extra degree of freedom for construction and power company personnel wrestling heavy cables onto new arms in very limited, cramped, humid space in manholes. 
     Upwardly-rotatable cable rack arms also accommodate faults in power lines. For example, when a short occurs even at a long distance in a power line, the cable will actually “jump,” or try to jump, as much as several inches. In older cable arms, such faults may break the arm in the area between the mounting orifices and the top of the arm. A broken arm cannot support the cables, placing additional loading on the adjacent arms and leading to additional failures. Allowing some rotation as in the embodiments described herein, typically from about 40 degrees to about 50 degrees, relieves the stress without breaking the arm. 
       FIG. 7  depicts a closer view of a single flange stanchion  12 , supported by wall mounts  13 . Stanchion  12  itself has an orifice  25  for mounting a cable rack arm. Wall mounts  13  have slots  27  so that the structure can be bolted to a support wall. Stanchion  12  has been formed by welding the central portion to wall mounts or end portions  13 , with resulting weld build-up  29  on both the top and bottom of the stanchion. In other embodiments, a single flange stanchion may be made in one piece by twisting the ends 90° instead of welding on additional end mount  13 . As mentioned above, one advantage of the adjustable cable rack arms described herein is that they may be used to retrofit existing stanchions, such as stanchion  12 . However, the retrofit will not go smoothly if the new arm does not include space to accommodate the weld build-up in situations where the stanchion is a welded assembly. Accordingly, as shown in the bottom view of  FIG. 8  and the closer, partial cross-sectional view of  FIG. 9 , the adjustable cable rack arm  30  slot  41  includes side reliefs  43   a ,  43 to accommodate weld build-up  29 . This makes the retrofit easier and prevents additional damage to the new arms  30  which do not have to be forced into place. 
       FIG. 10  depicts C-channel stanchion  51  bolted to wall  50  with bolts  59  and washers  61 . The stanchion is made from glass-reinforced plastic, such as glass-reinforced nylon or pultruded glass fiber and polyester or vinyl ester resin. Stanchion  51  includes a central web  55  with side flanges  57  formed at about 90° to the central web. Flanges  57  include orifices  53  for pins for mounting cable rack arms to the stanchion.  FIG. 11  depicts a two-position rack arm  20  and two three-position rack arms  30  mounted to stanchion  51  with pins  21 . In this type of installation, relief  49  is not used but is available if the cable rack arms are used with the older-type, double-flange steel stanchions.  FIGS. 10 and 11  depict the multiple orifices or pin holes  53  in the flanges  57  for cable rack arms. C-channel stanchion mounts to wall  50  via multiple bolts  59  through multiple orifices or holes (not shown) in web  55 . Using multiple mounting bolts improves stanchion load capacity, but the additional bolts pose a problem in that the heel or backside of the arm may interfere with a bolt head when the arm is installed and tilted into place. Side reliefs  43   a ,  43   b , also shown in  FIGS. 13 and 15 , overcome this problem by providing space in the arm to accommodate the bolt heads. 
       FIG. 12  depicts a partial cross-sectional view of the embodiment of  FIG. 11 . This view includes concrete wall  50 , anchor  28 , bolt  59 , web slot orifice  60 , C-channel stanchion  51  with web  55 , flanges  57  and orifices  53 .  FIG. 12  also depicts arm  30  with cable tie orifices  45  and top relief  49 . In the closer view of  FIG. 13 , which is also a partial cross-sectional view, washer  61  is visible under the head of bolt  59 . In addition, side relief  43   a  is also visible between the bolt  59  and the rear material of arm  30 . Thus, side reliefs  43   a ,  43   b  are useful in C-channel stanchions to provide clearance for mounting bolts. As noted above, side reliefs  43   a ,  43   b  are also useful in double-flange stanchions, allowing clearance of the cable rack arm around weldments. 
       FIG. 14  depicts a partial bottom cross-sectional view of  FIG. 12 , with a closer view in  FIG. 15 . Cable arm  30  is pinned to stanchion  51  with pin  21  and cotter pin  23 . The stanchion is bolted to concrete wall  50  with bolt  59  through slot orifice  60  and anchor  28 . Washer  61  is visible in closer view  FIG. 15 , which also depicts how side reliefs  43   a ,  43   b  allow clearance of the head  63  of bolt  59 . 
       FIGS. 16-18  depict installation of three additional and different non-metallic stanchions as described herein.  FIG. 16  depicts an E-channel stanchion installation  70 , with a non-metallic E-channel stanchion  71 . E-channel stanchion  71  includes a central web  73  with two outer flanges  75  and an inner, central flange  77 , the flanges perpendicular or about 90° to the web. A plurality of pin-mounting orifices  79  are provided on each of the inner and outer flanges. In addition, the central web  73  has a plurality of orifices (not shown) for bolts to mount the stanchion  71  to a concrete wall  18 . In this installation, two two-saddle arms  20  and two three-saddle arms  30  are mounted to stanchion  71 . Note that in  FIG. 16 , the flanges  75 ,  77  of E-channel stanchion  70  face in the same direction as cable rack arms  20 ,  30 , in the same manner as cable rack arm  30  and flanges  14   b  of C-channel stanchion  14  in  FIG. 2 . This configuration saves space in the installation while preserving the higher section modulus and strength of the E-channel and C-channel stanchions. 
       FIG. 17  depicts a stanchion installation  80  with a TEE-bar non-metallic stanchion  81  having a cross section in the shape of a T. TEE-bar stanchion  81  includes a central web  83  and a flange  85  formed at a right angle to web  83 . Pin-mounting orifices  89  are provided on flange  85 . In addition, the central web  83  has a plurality of orifices (not shown) for bolts to mount the stanchion  81  to a concrete wall  18 . In this installation, two two-saddle arms  20  and one three-saddle arm  30  are mounted to stanchion  81 . 
       FIG. 18  depicts a stanchion installation  90  with an L-angle non-metallic stanchion  91  having a cross section in the shape of an L. Angled stanchion  91  includes a web  93  and a flange  95  formed at a right angle to web  93 . Pin-mounting orifices  99  are provided on flange  95 . In addition, web  93  has a plurality of orifices (not shown) for bolts to mount the stanchion  91  to a concrete wall  18 . In this installation, three two-saddle arms  20  are mounted to stanchion  91 . 
     Discussion of Reinforcements for Pultruded Stanchions 
     As discussed above, a useful embodiment disclosed herein is a nonmetallic stanchion that is pultruded with a cross section in the general shape of a capital “C.”  FIGS. 21-21A  depict a cross-sectional view of the “C” channel stanchion. This embodiment of the “C” channel stanchion is nonmetallic. After the basic “C” channel has been pultruded, it is sawed to length and the holes for mounting it to a wall and the holes for attaching the arms are machine routed and/or drilled as required. In one embodiment, the nonmetallic material used in fabricating the “C” channel, by weight, is 44.5% polyester resin and 55.5% glass fiber. The glass fiber includes 33% unidirectional fiberglass roving (roving), 17% continuous filament glass fiber mat (CFM), 5% fiberglass cross layered knitted apertured mat (CLKM) and 0.5% synthetic surfacing veil (veil). The type of glass filament used in the roving, CFM, and CLKM is commonly known as E-glass. Other proportions may be used. The CFM is similar to a spun-bonded, non-woven reinforcement. In other embodiments, a standard woven (warp and weft) reinforcement mat may be used. 
     During the pultrusion operation, the roving, CFM, CLKM, and veil are completely wetted and saturated with the polyester resin. The polyester resin is the component that binds the fiberglass together forming a strong nonmetallic reinforced composite “C” channel stanchion. It is understood that other resins and other reinforcement fibers may be used. The roving is similar to Owens Corning fiberglas product number 399-113 yield and the CFM is similar to Owens Corning product number M-8643-2 oz/sq. ft and M-8643-3 oz/sq. ft. from Owens Corning, Granville, Ohio, U.S.A. The veil is similar to “NEXUS” veil from Precision Fabrics Group, Inc., Greensboro, N.C., U.S.A. The roving contributes longitudinal tensile strength and flexural strength. The CFM contributes strength in both the longitudinal and transverse directions. The veil provides a resin-rich surface for UV resistance and hand-friendliness. 
     The polyester, roving, CFM, and veil components described above have been used to pultrude and deploy a relatively small quantity of nonmetallic TEE-bar and “L” stanchions in recent years. These stanchions had insufficient strength and during the course of the work described herein, it was determined that a stanchion with higher load capacity was needed. In particular it was noted that the distribution of the roving and the mat throughout the resulting structure was not well controlled. Accordingly, the inventor developed a fiberglass cross-layered polyester yarn knitted apertured mat (CLKM) for placement in the stanchion during the pultrusion operation. Since the mat is cross-layered, one layer is oriented in the direction of the pultrusion, while the opposite layer is oriented transverse, about 90°, to the direction of pultrusion. In other embodiments, the transverse layer may be oriented up to plus or minus 15 degrees to the transverse direction. 
       FIG. 19  is the top view of a swatch of CLKM fabric  100 . The CLKM fabric has 6.5 longitudinal tows  101  of fiberglass per inch and 6.5 transverse tows  102  of fiberglass per inch. The tows  101 , 102  are knitted together with polyester yarn  103 .  FIGS. 19 ,  19 A,  20  and  20 A reveal in detail that the transverse tows  102  form one layer and the longitudinal tows  101  form a distinct second layer. Each tow  101 ,  102  is an untwisted bundle of 2,000 each (450 yield) 0.0166 mm (0.000654 in) diameter continuous glass filaments. The open channels  104  between the longitudinal tows and the open channels  105  between the transverse tows combined with the apertures  106  that penetrate through the CLKM fabric permit the polyester resin to wet-out and flow through the CLKM fabric. The CLKM fabric is pulled through the pultrusion die in the direction shown by the arrow  107 . While not being bound by any particular theory, it is believed that the layered structure allows greater penetration of the resin between layers and between and within tows in each layer, as well as within the discrete “windows” or apertures of the knitted reinforcement between each tow of each layer. 
     A cross-section of the “C” channel stanchion showing the reinforced polyester composite after it exits the pultrusion die is shown in  FIGS. 21 and 21A . In one embodiment, the structure is as follows. Two overlapping veils  108 ,  109  cover the outer surface. Two pieces of CFM  111 ,  112  are placed immediately inside the veil. One piece of CLKM  114  is placed at the center of the “C” channel thickness. One piece of CFM  115 ,  116  is placed on each side of the “C” channel thickness half way between an outer surface of the CLKM  114  and inner surface of the outer CFM  111 ,  112 . In one embodiment, the tows of roving, respectively 62 ea, 65 ea, 67 ea and 70 ea tows, are evenly distributed in compartments  117 ,  118 ,  119  and  120  respectively. As stated previously the veil  108 ,  109  constitutes 0.5% by weight of the “C” channel composite, the CFM  111 ,  112 ,  115 ,  116  is 17%, the CLKM is 5% and the roving is 33%. The 44.5% balance is the polyester resin which completely wets-out, saturates and adheres to all surfaces of the veil, CFM, CLKM, and roving. 
     The fiberglass-reinforced polyester composite pultrusion thus fabricated has increased transverse strength in the corners  121 ,  122  because the knitted yarn controls the distribution of the glass fiber tows. While the above has been described for a C-channel stanchion, other pultruded structures with this configuration will also have increased strength, whether they have the form of a TEE, an “L” or an “E” shaped cross section. A non-metallic cable rack arm made with the described corner reinforcements will have increased rigidity and strength, and because the position of the glass reinforcement is controlled, will also have a more reliable strength and stiffness. 
     One novel feature in the above described pultrusions that results in the increased transverse strength of the cable arm support stanchion is the inclusion of at least one fiberglass cross layered knitted apertured mat (CLKM) in which the tows and layers are restrained by a knit mesh. CLKM is the preferred fabric. The fiber or yarn used for the knit mesh may be polyester, cotton or other fiber. While a knitted holding structure is useful, other forms may be used, such as a stitched, purled, or even a woven form, so long as the additional fibers constrain the individual tows and layers into an integral structure. Other variations of the CLKM may also be used, in which the fiberglass fabric itself is woven, knitted or stitched. 
     The “C” channel stanchion described in detail above and the “E” Channel stanchion are new innovations in underground cable support and have advantages in their strength and rigidity. The TEE-bar stanchion and L-angle stanchion have been previously deployed as nonmetallic structures. The TEE-bar and L-angle stanchions cost less but also have less strength and stiffness, particularly when it is desired to use fewer mounting bolts, which is usually the situation. There are many possible embodiments of the present invention, of which only a few have been described herein. It is intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.

Technology Category: 4