Abstract:
A cable tray assembly for supporting cables, wires and the like. The assembly includes an elongate rail including an open channel extending along the length thereof. The assembly further includes at least one support member. Finally, the assembly includes a locking connector cooperating with the support member. The connector is sized and configured for insertion into the channel whereby insertion of the connector into the channel simultaneously locates the member at a position along the rail and fixedly secures the arm to the rail in the absence of fastening hardware.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/038,315 filed Feb. 25, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to cable tray assemblies for supporting electrical wires, cables and the like, and more particularly, to modular components for forming a cable tray assemblies which are easy to manufacture, ship and assemble. 
     Cable tray assemblies are well known for use as a support system for carrying electrical cables, wires, tubing, piping or other conduits over various distances in buildings and other commercial structures. The cable tray assembly provides a support for running the wires throughout various locations in the facility. Cable trays are typically suspended from the ceiling or walls in order to provide a non-intrusive path for the cable with full use of the work spaces below. Due to the amount of cable and conduits running through modem facilities, cable trays are also available which support cables at multiple elevations. 
     Traditional cable trays arc bulky, cumbersome devices which are difficult to manufacture, ship and assemble. Improvements in cable tray construction provide for the manufacture of various modular interfitting components which allow the user flexibility in assembling a cable tray system for a particular design. Such components are also easier to manufacture and ship. 
     Two examples of such modular cable tray assemblies are shown in U.S. Pat. No. 5,123,618 to Guterman, et al. and U.S. Pat. No. 5,564,658 to Rinderer, the disclosures of which are incorporated by reference herein for all purposes. By way of example, Rinderer discloses a support system having a plurality of supports vertically extending from a rail. Each support has a series of horizontally extending arms which support transmission cables. The supports are inserted into cutouts formed in the rail. There are therefore only a limited (and predefined) number of locations where a support may be placed. This limitation can lead to difficulty in assembling support systems in applications where flexibility in placement is desired. 
     Other prior art tray assemblies require the use of various mechanical fasteners to attach the support arms to the support rail. These mechanical fasteners generally require the use of installation tools. The need to install a mechanical fastener at the location of each support arm/rail interface is quite labor intensive, resulting in increased installation time and increased costs. 
     Accordingly, it would be desirable to provide a cable tray system which is easily field assembleable and which provides more assembly options to the user so as to make the cable tray assembly more adaptable to each user&#39;s particular cable tray needs. 
     SUMMARY OF THE INVENTION 
     The present invention, which addresses the needs of the prior art, relates to a cable tray assembly for supporting cables, wires and the like. The assembly including elongate rail including an open channel extending along the length thereof. The assembly further includes at least one support member. Finally, the assembly includes a locking connector cooperating with the support member. The connector is sized and configured for insertion into the channel whereby insertion of the connector into the channel simultaneously locates the member at a position along the rail and fixedly secures the arm to the rail in the absence of fastening hardware. 
     In one preferred embodiment of the present invention, the channel includes a pair of opposing side walls, each of the side walls defining a top edge. The connector includes a saddle body and a pair of deflectable spring clips, the saddle body defining a plane. The spring clips extend perpendicularly from the plane whereby insertion of the connector into the channel causes engagement between the clips and the side walls. 
     In an alternative embodiment of the present invention, the channel includes a pair of opposing side walls, each of the side walls defining a top edge. The assembly further includes a trunk for spacing a support member a distance from the rail. Finally, the connector includes a generally closed body having bottom and side walls thereby defining a trunk-receiving cavity for receipt of the trunk. The connector includes opposing cantilevered spring clips sized to engage the side walls when the connector is inserted into the channel. 
     As a result, the present invention provides a cable tray system which is easily field assembleable and which provides more assembly options for the user so as to make the cable tray assembly more adaptable to each user&#39;s particular cable tray needs. Particularly, the present invention provides a cable tray system wherein the support members are locateable at any position along the length of the rail, and may be attached to the rail in the absence of fastening hardware or use of installation tools. As a result, installation of the present cable tray system requires reduced installation time thereby resulting in decreased costs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the cable tray assembly of the present invention; 
     FIG. 2 is a partial perspective view showing an attachment clip; 
     FIG. 3 is a perspective view of a splice connector for securing together rail sections; 
     FIG. 4 is a elevational view of two rail sections connected together with the splice connector of FIG. 3; 
     FIG. 5 is a sectional view of the splice connector and rail section taken along line  5 — 5  of FIG. 4; 
     FIG. 6 is an exploded perspective view of an alternative embodiment of the splice connector; 
     FIG. 7 is a elevational view of the splice connector of FIG. 6; 
     FIG. 8 is an exploded perspective view of a modified connector secured together with a threaded rod; 
     FIG. 9 is an exploded perspective view of the connector of FIG. 8 secured together by a nut and bolt assembly; 
     FIG. 10 is an exploded perspective view of an alternative connector for joining rail sections at vertically spaced locations; 
     FIG. 11 is an exploded perspective view of an alternative embodiment of a connector which allows for rail sections to be angularly adjusted to an axially vertical plane; 
     FIG. 12 is an exploded perspective view of the connector of FIG. 11 including an offset bar; 
     FIG. 13 is an exploded perspective view of a rail and ceiling attachment assembly; 
     FIG. 14 is an exploded perspective view of a rail and floor bracket assembly; 
     FIG. 15 is an exploded perspective view of a vertical coupling assembly; 
     FIG. 16 a  is an exploded perspective view of a rail section and end wall bracket; 
     FIG. 16 b  is an exploded perspective view of an alternative embodiment of an end wall bracket; 
     FIG. 16 c  is an exploded perspective view of a further alternative embodiment of an end wall bracket; 
     FIG. 16 d  is an exploded perspective view of a further alternative embodiment of an end wall bracket; 
     FIG. 17 is an exploded perspective view of a multi-purpose bracket of the present invention; 
     FIG. 18 is a perspective view of a wall mounted saddle and rail; 
     FIG. 19 a  is a perspective view of a spaced wall support; 
     FIG. 19 b  is a perspective view of an alternative embodiment of the spaced wall support; 
     FIG. 20 is a perspective view of a central intersection assembly; 
     FIG. 21 is a partial cross-sectional view taken along line  21 — 21  of FIG. 20; 
     FIG. 22 is an exploded detail of the intersection assembly of FIG. 20; 
     FIG. 23 is an exploded perspective view of an alternative embodiment of the intersection assembly of FIG. 20 without the use of planar members; 
     FIG. 24 is an exploded perspective view of an angularly adjustable bracket connector; 
     FIG. 25 a  is an exploded perspective view of a T-coupler; 
     FIG. 25 b  is an exploded perspective view of an elongate crossover bracket; 
     FIG. 26 is an exploded perspective view of an offset bracket; 
     FIG. 27 is an exploded perspective view of a rail section and curved drop shield; 
     FIG. 28 is a perspective view of a rail section including an upstanding barrier; 
     FIG. 29 is an exploded perspective view of rail sections joined by an outboard coupling assembly; 
     FIGS. 30 a - 30   e  illustrate various alternative embodiments of the outboard coupling assembly; 
     FIG. 31 is an exploded perspective view in an electrical fixture mountable to a rail; 
     FIGS. 32-33 illustrate the various embodiments of support hardware securable to the rail; 
     FIG. 34 a  is an elevational view of a rung and spring clip connector having a portion removed to clearly show a gripping element of the present invention; 
     FIG. 34 b  is a top elevational view of the rung with the spring clip connector of FIG. 34 a;    
     FIG. 34 c  is a sectional view taken along line  34   c — 34   c  of FIG. 34 a;    
     FIG. 35 a  is a elevational view of the rail section and rung including a spring clip prior to insertion into the rail; 
     FIG. 35 b  is an elevational view of the rail and rung with the spring clip engaged in the rail; 
     FIG. 36 is a perspective view of a rail having an alternative embodiment of a rung attached thereto. 
     FIG. 37 is a perspective view of a rail having a further alternative embodiment of the rung attached thereto; 
     FIG. 38 a  is a front elevational view of a rung having a truck extending therefrom; 
     FIG. 38 b  is a partial sectional view of the rung of FIG. 38 a  taken along line  38   b — 38   b  thereof; 
     FIG. 38 c  is a front elevational view of the spring clip of FIG. 38 a;    
     FIG. 38 d  is a side elevational detail view of the spring clip of FIG. 38 b;    
     FIG. 39 is a perspective view of a rail having a pair of rungs attached thereto; 
     FIG. 40 is an elevational view of the rung of FIG. 38 a  prior to insertion in the rail; 
     FIG. 41 is a partial elevational view of the rung of FIG. 38 a  inserted and secured to the rail; 
     FIG. 42 is a perspective view of a rail having rung secured thereto to support cable at various elevations; 
     FIG. 43 is a perspective view of an alternative embodiment of the rail having open channels formed on both ends thereof; 
     FIG. 44 is an elevational view of the rail of FIG. 43 including alternative embodiment of rungs; 
     FIG. 45 is a perspective view of the rail of FIG. 43 having rungs secured thereto to support cable at various elevations; and 
     FIG. 46 is a perspective view of a further alternative embodiment of the rail. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-3 herein, the cable tray assembly  10  of the present invention includes a spine or rail  12  which is an elongate generally rectangularly-shaped member which may be formed of extruded aluminum, steel, rigid plastic or any other material well known in the art. Rail  12  includes a generally closed rectangular channel  14  therethrough and a open ended channel  16  thereadjacent running the length of rail  12 . The opening to the channel is defined by a pair of spaced walls  15 . A plurality of support members, preferably rungs  32 , are secured to rail  12  adjacent open channel  16 . The rungs define a plane in which the cables, conduits and the like may be supported. 
     In the present illustrative embodiment, rail  12  is provided in discrete rail sections  12   a  which are provided in various lengths. Preferably, the rail sections  12   a  are provided in either 10 or 12 foot lengths. Moreover, each rail section  12   a  may be cut by the end user to a desired length to assemble, in longitudinal succession, a plurality of rail sections of any desirable length. Rail sections  12   a  may be joined together in a variety of ways to form a support system of almost any desired length. 
     One or more rail sections  12   a  may be supported from a ceiling or other overhead structure by a clevis hanger  18 , as shown in FIG.  1 . Clevis hanger  18  includes a rail support member  20  for accommodating rail  12  and a threaded rod  22  extending upwardly therefrom. Threaded rod  22  may be attached to a beam clamp secured to an I-beam (not shown) so as to effectively hang the rail  12  from the ceiling at a preselected distance therefrom. Appropriate hardware  24  may be used to secure the clevis hanger  18  to the rail  12 , e.g., nut member  24   a  may be positioned within channel  16  to provide a member for threadedly engaging screw  24   b . As may be appreciated, one or more clevis hangers  18  may be employed for each rail section  12   a  to support the assembly of rail sections to the ceiling. 
     Rail sections  12   a  support a plurality of rungs  32  at spaced locations therealong. Rungs  32  are designed to hold or carry the electrical wires or cables (not shown) at a location laterally offset from rail  12 . Each rung  32  includes an elongate extent  34  having a planar surface  34   a  on which the wires or cables may be supported. The planar surface  34   a  includes a plurality of spaced apertures  34   b  extending therethrough which permit securement devices (not shown) to be threaded therethrough to secure the wires and cables supported by the rungs. Devices such as cable ties and pipe straps may be used in combination with the rungs to support the wires and cable thereto. Preferably, the rungs include at opposed ends thereof, upturned sections  36 . The upturned sections provide a U-shaped configuration to the rungs which generally help contain the wires supported by the rungs. Rungs  32  are rigidly securable to rail section  12   a  in a manner set forth below. 
     Referring to FIG. 2, one technique for attaching rungs  32  to rail  12  is shown. Rungs  32  are attached to the undersurface of rail  12  adjacent open ended channel  16  and may be selectively positioned along the length of rail  12 . An attachment clip  38  may be inserted into open ended channel  16  through end  12   b  of rail section  12   a . Clip  38  is slidably movable along the length of rail section  12   a , thus the longitudinal position of each rung  32  may be readily adjusted. Accordingly, the spacing between rungs  32  may be adjusted as desired. In order to secure a rung to rail  12 , rung  32  is placed up against open ended channel  16  and a conventional bolt  38   a  is inserted through the rung and through the open end of the channel and into threaded engagement with attachment clip  38 . Securement of the bolt  38   a  to the attachment clip  38  clamps a portion of channel side walls  15  between rung  32  and clip  38 , thereby securely fixing the rung to the rail to prevent longitudinal movement of the rung once it is attached. 
     In order to adjust the length of the rail  12 , individuals rail section  12   a  may be joined together to create a suitable run. Referring to FIG. 3, a splice connector  26  is shown which connects together a pair of rail sections  12   a  in longitudinal succession. Connector  26  includes a central connector body  26   a  and a pair of oppositely extending wings  26   b . Wings  26   b  are insertable into closed channel  14  at each end  12   b  of rail section  12   a  to support adjacent rail sections  12   a  together. Appropriate fastening hardware  26   c  may be used to secure splice connector  26  to the ends of rail sections  12   a  which may be provided with through holes  12   c  to accommodate fastening hardware  26   c . Furthermore, connector body  26   a  may include a central aperture  26   d  to support threaded rod  22  therethrough so that the connector  26  may be used to hang or support the rail sections from an overhead support. FIGS. 4 and 5 show in further detail the interconnection of a pair of rail sections  12   a  in longitudinal succession employing connector  26 . 
     With reference to FIGS. 6 and 7, an alternative embodiment of a splice connector is shown. Splice connector  26 ′ is formed similarly to connector  26  but further includes an axially extending slot  25  formed in connector body  26   a ′. Slot  25  permits threaded rod  22 ′ to be radially inserted into splice connector  26 ′, thereby permitting the rails to be secured to elongate rods which have been previously installed. A plate  27  may be inserted within connector  26 ′ overlying slot  25  and secured to splice connector  26  by a pair of fasteners  24  threadably engaged therewith as shown in FIG.  6 . 
     Referring to FIG. 8, a modified connector  28  is shown. Connector  28  functions in a manner similar to connector  26  in that it supports and fixedly joins a pair of rail sections  12   a  together in longitudinal succession. However, connector  28  is modified in that wings  28   b  thereof are interconnected at a central pivotal location  28   a  so that the wings may rotate or pivot with respect to each other. This allows splicing or connection of two rail sections to take place at an adjustable angle enabling the assembled rails  12  to negotiate a turn allowing the wires supported thereby to be routed in various directions. 
     Connector  28  may be employed with threaded rod  22  to support rail sections  12   a  from an overhead support. Threaded rod  22  may also act as a hinge pin about which the elements of connector  28  may rotate. Once the desired angle between rail sections  12   a  is obtained, the fastening hardware may be tightened to lock the rails in a fixed orientation. In situations where there is no need to provide such overhead support at each location, the threaded rod may be substituted for by a conventional nut and bolt assembly  29  such as shown in FIG.  9 . 
     Referring now to FIG. 10, a further connector  30  is shown. Although connector  30  is substantially similar to connector  28  described above, the opposed wings  30   b  are positioned at vertically spaced locations. Thus, interconnection between adjacent rail sections  12   a  can be accomplished not only at varied angles but also at different heights. The adjustment in vertical separation between rail section  12   a  may be achieved by securing each connector element  30   b  between two nut fasteners. Therefore, each connector element may be independently fixed on rod  22 . Such positioning allows the rails to be vertically offset and permits cables supported by the cable tray assembly to be routed over and under various obstacles such as piping, HVAC ducts and the like. As with connector  28 , a threaded rod  22  may be used in combination with connector  30  to support the rail sections  12   a , or a standard nut and bolt combination (not shown) may be employed where no support is required. 
     As shown in FIG. 11, in addition to providing a connector which permits rail sections  12   a  to be angularly adjusted in a longitudinal plane, the present invention includes a connector  120 , which permits rail sections to be angularly adjusted in a vertical plane. Connector  120  includes a winged portion  124  similar to that of connector  26 . The winged portion  124  is insertable within the rail section  12   a . The opposing end of connector  120  includes a tang  126  having a throughhole  128  formed therethrough. Throughhole  128  of one connector may be aligned with a throughlhole of an adjacent connector and rotatably secured thereto by fastening hardware  24 . Once the desired angles between rail sections  12   a  is achieved, the hardware can be tightened thereby locking the rail sections at a set angle. 
     As shown in FIG. 12, connectors  122  of adjacent rails  12   a  may incorporate an offset bar  130  extending therebetween. Such a configuration permits adjacent rail sections  12   a  to be vertically offset in addition to being angularly offset. 
     The cable tray assembly of the present invention, due to its modular design, further allows the use of various accessories to provide greater flexibility in the mounting of the cable tray as well as the routing of wires in a given location. Referring to FIG. 13, a ceiling attachment assembly  40  is shown. Ceiling attachment assembly  40  may be used in conjunction with connector  26  shown in FIG. 3 to provide more stability to the longitudinally extending rail  12 . Ceiling attachment assembly  40  employs a pair of threaded rods  22  mounted to connector  26  by upper and lower saddle U-shaped assemblies  42  and  43 . The upper saddle assembly  42  may be mounted directly to an overhead structure or may employ a further threaded rod  22  for hanging purposes. 
     FIG. 14 shows rail section  12   a  employed with a lower floor bracket  44  which allows the rail to be mounted spaced from a floor or other horizontal support in situations where wire routing in this manner is necessary. A nut fastener  24   a  may be positioned within slot  16  and engaged by fastening bolt  24   b . Tightening of the nut and bolt combination will positionally fix floor bracket to rail section  12   a.    
     FIG. 15 shows a vertical coupling assembly  46  which allows rail sections  12   a  to be interconnected at a right angle to one another. Assembly  46  includes a first bracket  46   a  mountable to a central location of one rail  12   a  and a second bracket  46   b  which is mountable to the end of a orthogonally extending rail section  12   a . Nut fasteners  24   a  are slidably positionable within rail channel  16  and secure the first and second brackets  46   a  and  46   b  to their corresponding rail sections  12   a . The slidable nut fastener permits one rail section  12   b  to be joined at substantially any longitudinal position along the length of the other rail section  12   b.    
     FIG. 16 a  illustrates an end wall bracket  48  which allows the last rail section  12   a  to be mounted directly to a wall where the rail section terminates. Wall bracket  48  has a U-shaped portion which engages the side walls  12   d  of rail section  12   a  and helps support and maintain the rail  12  in proper alignment. Nut fasteners  24   a  and bolts may be used to secure rail section  12   a  to wall bracket  48 . Additional embodiments of an end wall bracket are shown in FIGS. 16 b-d . End wall brackets  48 ′,  48 ″ and  48 ′″ may be secured to rail sections  12   a  with fastening hardware  24 . 
     A multi-purpose bracket  50  which may be used to secure rail  12  to various support structures found in commercial construction is shown in FIG.  17 . Bracket  50  preferably includes a S-shaped configuration with a top flange  50   a  and a bottom flange  50   b  extending from a central member  50   c . A throughhole  50   d  may be provided on top flange  50   a  in order to permit bracket  50  to be secured to a structure. Additionally, by way of a nut fastener  24   a  inserted in open channel  16  and bolt  24   b , bracket  50  may position at substantially any location along the length of rail section  12   a.    
     FIG. 18 shows a wall mounted saddle  52  which may be used to mount rail  12  directly onto a vertical wall or the like. In such situations, modified rungs  33  are provided. Rungs  33  are substantially similar to rungs  32  but only extend to one side of rail  12  thus allowing the rail to be mounted directly onto a vertically extending wall. 
     In situations where wall mounting is desired and use of standard rung  32  is also desired, a spaced wall support  54  such as shown in FIG. 19 a  may be provided. Spaced wall support  54  may be mechanically secured to a wall or other vertical surface and includes outwardly extending arms  54   a  and  54   b  terminating at a connection point to connector  26 . Thus, the rail  12  may be mounted to a wall at a spaced location therefrom to enable standard rungs  32  to be employed. In an alternative embodiment shown in FIG. 19 b , wall support  54 ′ may include a pair of back to back slotted channel members  57  which are securable to connector  26 . 
     The cable tray assemblies may be arranged in various configurations so as to provide versatility in the running of wires or cables. Referring now to FIGS. 20-23, various components which allow for different arrangements of cable tray assemblies are shown. Specifically with respect to FIGS. 20-22, a central intersection assembly  60  is shown. Intersection assembly  60  allows the truncation of various rail sections  12   a  thereat so that wire bundles may be routed to different locations within a facility. Intersection assembly  60  is shown in exploded view in FIG.  22  and includes a pair of plate members  62  mounted to a central support  64 . Elongate brackets  66  are used to secure the planar members  62  to the central support  64 . As shown in FIG. 20, brackets  66  are attached below the ends of rail sections  12   a  via nut fasteners  24   a  inserted within rail open channel  16  and bolts  24   b  to support rail sections  12   a  to the intersection assembly  60 . In addition the rail section  12   a  longitudinally aligned with central member  64  may be directly attached thereto. 
     It is contemplated that bundles of wire or cable may be brought to the intersection assembly  60  by one or more cable tray assemblies whereupon various combinations of wires and cables may be routed in different directions employing other cable tray assemblies attached at the intersection assembly  60 . It is also contemplated that intersection assembly  60  may be employed without planar members  62  and with a relatively narrow central member  64   a  as shown in FIG.  23 . 
     In FIG. 20, various cable tray assemblies are shown intersecting at substantially right angles. However, as shown in FIG. 24 appropriate adjustable brackets  66   a  may be employed so that rail sections may intersect at angles other than 90°. Bracket  66   a  may include a first and second bracket element  66   b  and  66   c  that are joined together about a piece of fastening hardware such as a bolt  24   b . Once the desired angle between interconnected rail sections  12   a  is obtained, the fastening hardware  24  may then be tightened in order to fix the angle. Various other techniques used to arrange rail assemblies with respect to one another may be also employed. 
     As shown in FIG. 25 a , two rails  12   a  may be abutted in a T-shaped fashion employing a T-coupler  65 . T-coupler  65  includes a straight bracket  65   a  to secure one rail section  12   a  to another rail section  12   a  perpendicular thereto. Also an end cap  67  is provided to cover the end of one of the rail sections  12   a . As shown in FIG. 25 b , three sections  12   a  may be interconnected in a cross configuration employing an elongate cross-over bracket  68 . 
     Referring now to FIG. 26, two rails sections  12   a  may be interconnected in longitudinally successive fashion but horizontally offset from one another by using an offset bracket  69 . One end of offset bracket  69  may include an elongate slot to permit adjustment in the offset distance. 
     Additional accessory components may be used in combination with rail  12  of the present invention. As shown in FIG. 27, a generally curved drop shield  70  is provided. Drop shield  70  may be attached to rung  32  in a manner shown in FIG. 27 so as to permit cables to be taken out of the bundle and dropped downwardly for use. In certain situations, especially with fiber optic cable, it is necessary to assure that a large radius of curvature is provided when dropping cables from the bundle. Drop shield  70  provides such gradual radius of curvature when dropping cables from the bundle held by rung  32 . 
     A further accessory which may be provided for use with cable tray assembly  10  is a upstanding barrier  72  shown in FIG.  28 . Barrier  72  is secured to and across several rungs  32 . Barrier  72  may be used to separate cables of one type from cables of another type being carried by cable tray assembly  10 . Such separation may be required for separating power cables from other types of transmission cables. 
     In an alternative embodiment, as shown in FIGS. 29 and 30, rail  12  may be used as an electrical raceway to carry power conductors within. FIG. 29 shows a pair of rail sections  12   a  interconnected by an outboard coupling assembly  80 . The various contemplated embodiments of coupling assembly  80  are more fully shown in FIGS. 30 a - 30   e . In all the embodiments shown, a portion of a coupling bracket  80   a  is inserted into the open ended channel  16  of rail  12  at an end  12   b  thereof. Coupling bracket  80   a  may be secured to rail section by a variety of bracket elements  80   b  to  80   f . These bracket elements are positioned outside channel  16  and provide a throughhole for a bolt to pass therethrough and threadedly engage coupling bracket  80   a . In an alternative embodiment shown in FIG. 30 c , nut fasteners  24   a  may be inserted within channel  16  above coupling bracket  80   a ′. Bracket  80   a ′ is substantially similar to bracket  80   a  but includes clearance holes instead of threaded holes. Thus, the ends of two rail sections  12   a  may be coupled together in longitudinal fashion leaving the closed channel  14  unobstructed so as to function as a cable raceway. As shown in FIG. 28, electrical cables  81  may be routed through closed channel  14  of rail  12  which thereby functions as the electrical cable raceway. 
     As shown in FIG. 31, an electrical fixture such as a light fixture  83  may be supported from the cable tray assembly and the wires (not shown) housed by the raceway may be electrically connected to fixture  83 . Thus, the cable tray assembly not only routes wires but also supports electrical fixtures or other electrical devices. 
     The versatility of the cable tray assembly of the present invention is further shown by other accessories which may be employed therewith. Open ended channel  16  of rail  12  is formed to have a configuration which closely approximates conventional struts manufactured by the assignee herein. Such construction allows the open ended channel to accommodate conventional support hardware for supporting pipes and other structures to rail  12 . As shown in FIGS. 32-33, various pipe clamps may be employed in combination with rail  12  to support pipes or other structures to rail  12 . Pipe clamps  87  and  89  are secured to the open ended channel  16  of rail  12  in a manner which is substantially similar to the manner in which such clamps are secured to conventional struts. Such struts and accessories may be of the type sold under the trademark SUPERSTRUT by the assignee herein. 
     While the above-described rungs may be secured to the rails using attachment clip  38  or other suitable mechanical fasteners, alternative attachment techniques are also provided by the present invention which do not require fastening hardware. As shown in FIG. 34 a , one particularly preferred embodiment of the present invention utilizes a locking connector for mounting and securing the rungs to the rail. Referring now to FIGS. 34 a - 34   c , locking connector  90  includes a generally saddle-like body  92  which is sized such that it may be disposed over rung  32 . Saddle body  92  includes opposing torque-resisting fingers  140  which engage the sides of the rung to resist relative rotational movement between the connection and the rung. Connector  90  is then secured to the rung by a fastener, e.g., rivet  94 . 
     Extending upwardly from a plane X defined by saddle body  92  are a pair of oppositely directed spring clips  96  (preferably formed of spring steel) which may be inserted into the open ended channel  16  of rail  12 . Each of spring clips  96  has a generally inverted V-shaped cross-sectional profile which terminates at edges  96   a . Connector  90  permits a rung to be snapped into rail  12  and fixedly secured thereto without the need for additional mounting hardware or tools. 
     Referring to FIGS. 35 a ,  35   b  and  36 , the spring clips  96  will lock into the channel securing the rung  32  thereto at any desired location therealong. As will be appreciated by those skilled in the art, spring clips  96  are sized for insertion into channel  16 . In this regard, spring clips  96  are inserted into channel  16  in a direction perpendicular to the plane defined by channel  16 . As the spring clips are inserted into channel  16 , a living hinge  96   b  allows a flange  96   c  to deflect inward toward a support leg  96   d . Once the clips are fully inserted into the channel, living hinges  96   b  urge flanges  96   c  outward to their original undeflected orientation. As shown in FIG. 36, edges  96   a  are therefore urged into intimate contact with the top edges  15   a  of side wall  15 , thereby preventing withdrawal of the spring clip from the channel. Snap-lock connector  90  may further include a pair of upwardly-extending opposed rigid walls  144  positioned adjacent to support legs  96   d . Walls  144  prevent legs  96   d  from inward rotational deflection when inserting the rung into channel  16 , thus ensuring that deflection during insertion of the connector into the channel is substantially limited to that of flanges  96   c  about living hinges  96   b . It is to be appreciated that the coupling of connector  90  to channel  16  is accomplished in one operation (i.e., insertion of the connector into the channel) and without the need for fastening hardware or tools. It should be further appreciated that the novel configuration of the present invention allows mounting of the rungs at any location along the length of the channel, not simply at predetermined locations as typically seen in the prior art. 
     In order to resist forces acting in a direction along the length of the rails, spring clip connector  90  may further include a plurality of gripping elements  130  which are engageable with opposed side walls  15  of the rail. Gripping elements  130  include pointed lugs which frictionally engage a face portion  15   b  of an adjacent side wall  15 . In one preferred embodiment, four gripping elements  130  are included on each spring clip connector  90 , with one gripping element disposed adjacent each end of each spring clip. A pair of torque-resisting legs  91  which extend upwardly from plane X may also be provided on saddle body  92 . Legs  91  are sized to closely fit between side walls  15  and assist the connector  90  in resisting rotational forces imparted thereon. 
     It will be recognized that spring clip connector  90  may be employed with various rungs, including rungs  32  shown in FIG. 34 a , rungs  32   a  shown in FIG.  36  and rungs  33  shown in FIG.  37 . 
     Referring to FIGS. 38 a - 42 , another preferred embodiment of the present invention utilizes locking connector  93 . Connector  93  is particularly adapted for installations wherein the rungs are vertically spaced from the rail. As shown more specifically in FIGS. 38 a - 38   d , connector  93  is secured to one end of a vertical trunk  95 , which is preferably rectangular in cross section. The rungs are then mounted to trunk  95 , e.g., half rung members  97   a  and  97   b . Half rung members  97   a  and  97   b  may be connected to the trunk by rivets  99  or other suitable mechanical fastening means. 
     Connector  93  allows the trunk and attached rung to be secured to channel  16  of rail  12 . This connection may be achieved without the need for fastening hardware or tools. Connector  93  includes a pair of outwardly directed spring clips  93   a  extending downwardly from two opposed sides thereof. Spring clips  93   a  insertably lock into channel  16  of rail  12 , as shown in FIGS. 39,  40  and  41 . Each spring clip  93   a  includes a distal end having gripping elements  93   b  formed thereon. Gripping elements  93   b  engage the top edges of side walls  15  when the connector is inserted in open channel  16 . To ensure that gripping elements  93   b  engage side walls  15 , connector  93  includes a pair of opposing biasing tabs  93   c  extending outwardly and upwardly from the bottom of connector  93 . Tabs  93   c  engage rail  12  and are deflected as connector  93  is urged into open channel  16 . Tabs  93   c  therefore tend to urge gripping elements  93   b  into top edges  15   a  thus locking the rung in place on rail  12 . In one preferred embodiment, spring connector  93  is integrally formed from a single piece of thin steel. 
     In addition to connectors  90  and  93  described hereinabove, it is contemplated herein that locking connector  90  could be alternatively configured to utilize locking mechanism other than the mentioned spring clips, e.g., a connector utilizing a ¼-turn locking mechanism. In such alternative embodiments, the locking connector allows simultaneous location at any position along the length of the rail and securement thereto with one coupling action and in the absence of fastening hardware or tools. 
     As shown in FIG. 39, a rung section may be employed on only one side of the trunk or may be employed on both sides of the trunk as shown in FIG.  42 . Similarly, either straight rungs or rings with upturned edges may also be employed. 
     It is further contemplated that one set of rail sections  12   a  may employ rungs which are directly mounted to the rails as well as rungs which are supported at a vertically spaced relationship to the rails by use of trunk  95  as shown in FIG.  42 . Trunks could also be produced in varying lengths to allow for support of cable  100  at various elevations. This intermixing of different levels of rungs allows wires and cables to be supported in parallel relationship but at different horizontal positions with respect to rail  12 , thereby allowing a greater amount of cables and the like to be supported. Additionally, since each rung supports cable at only one level, an installer can customize the installation choosing just the components necessary to fit the application thereby eliminating the use of unnecessary rungs. 
     The use of the spring clip connectors shown in FIGS. 34-41 allows the trunk or rung to be attached to the open ended channel of the rail without the need for a. secondary installing operation. Also, the snap-in feature allows easier assembly so that the cable tray components can be shipped disassembled preventing damage thereto. Furthermore, rungs and/or trunks can be easily added to the cable tray assembly. 
     The present invention also contemplates the use of rails having various configurations. In an alternative embodiment shown in FIGS. 43-45, rail  110  may be similarly formed to rail  12  but may further include an open ended channel  112  on both the top and bottom portions of rail  110  having closed channel  114  disposed therebetween. In order to provide multi-layer support, rungs  32  may be positioned in both open channels  112  resulting in vertical spacing of the rungs  32 . In this embodiment, rungs  32  are secured to open channels  112  by either attachment clip  38  or spring clips  93 ,  96  described hereinabove. 
     It will be appreciated that connector  90  must be secured to a lower face  34   c  of rung  32  (opposite planar surface  34   a ) when such rung is to be connected to an upper open channel formed in rail  110  (see FIG.  43 ). In this embodiment, a collar  142  may be utilized to facilitate the attachment of connector  90  to the rung. It will not noted that torque-resisting fingers  140  still engage the sides of the rung even when the connector is secured to the lower face of the rung. 
     Rungs having various configurations such as curved and straight rungs  32 ,  32   a  extending from both sides of rail  110 , and curved and straight rungs  33 ,  33   a  extending from only one side of rail  110  may be fixed to rail  110  as shown in FIGS. 43-45. In addition, a third vertical level of support may be provided by employing a vertical trunk  95  having a rung  32  attached as shown in FIG.  45 . 
     A further alternative embodiment shown in FIG. 46, includes a channel  116  having two open channels  118  located back-to-back, thereby providing a mounting surface on the top and bottom of rail  116 . In this embodiment the centrally disposed closed channel  14  is eliminated. As with the rails described above, all types of rungs may be secured along the length of rail  116 . 
     It will be appreciated that the present invention has been described herein with reference to certain preferred or exemplary embodiments. The preferred or exemplary embodiments described herein may be modified, changed, added to or deviated from without departing from the intent, spirit and scope of the present invention, and it is intended that all such additions, modifications, amendment and/or deviations be included within the scope of the followings claims.