Abstract:
A cable management system includes an opposed pair of articulated A-frame support assemblies that are connected by a cable support platform, such as a roller. The A-frame support assemblies may be reach between an electrical system chassis and an equipment rack in a manner that permits the elevation of the cable support platform to change concomitant with extensile and de-extensile motion of the electrical system chassis relative to the equipment rack. This change in elevation manages slack in the cable to feed cable forwardly during extensile motion of the electrical system chassis and to pull cable rearwardly with de-extensile motion.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to the field of cable management systems that are used to prevent tangling and resultant damage to electrical and optical cables that are used to transmit data or power. More specifically, the cable management systems are deployed to facilitate movement of one electrical chassis relative to another body without having to disconnect the cables. 
     2. Discussion of the Related Art 
     A variety of cable management systems run horizontally, as opposed to vertically. It is increasingly the case, in rack-mounted systems, that forward and rearward extensile motion of an electrical system chassis is desired without having to disconnect the cables from the chassis. The cable management systems all generate excess slack in the cables. Some degree of cable slack is required to permit the forward and rearward chassis motion; however, a relatively large amount of slack is required in practice, which becomes subject to tangling that interferes with forward and rearward motion of the chassis in horizontally-tracked systems. For example, U.S. Pat. No. 6,233,791 uses a resilient U-clip to secure cables to static surfaces. This type of fixed system does not facilitate movement of an associated electrical system chassis. U.S. Pat. No. 6,070,742 describes a horizontally extensible tray that is used to support cables in a rack mounted system; however, full inward extension of the tray is associated with the formation of cable slack that eventually develops tangles, particularly, when many different cables are present. 
     U.S. Pat. No. 6,170,784 discloses a variable height cable management system having a fixed horizontal brace that may be selectively attached across two upright supports. The height of the structure does not vary with motion of the associated electrical system chassis and, consequently, cable movement over the horizontal brace subjects the cables to undue wear. Furthermore, greater lengths of cable are required to accommodate the height of the horizontal support brace. 
     There remains a need for an improved cable management system that is capable of managing more cables and longer lengths of cables that can be managed by prior cable management systems. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the problems that are outlined above by providing a cable management system that facilitates forward and rearward motion of a rack-mounted electrical chassis. The cable management system uses articulated A-frame supports that vary with height depending upon the degree of forward and rearward motion. Thus, the cable management system is able to manage more cables and greater lengths of cables that can be managed by prior cable management systems. 
     The cable management system comprises an opposed pair of articulated A-frame support assemblies. Each of the articulated A-frame support assemblies comprises a first segment, a second segment, and a knee joint coupling the first segment with the second segment in a manner permitting the knee joint to move in elevation between a low position and a high position concomitant with arcuate pivoting motion of the first segment and the second segment. A cable support platform is coupled with the pair of the articulated A-frame supports to provide a horizontal surface for support of cables. 
     The first segment of each articulated A-frame support optionally comprises an extensible leg that permits a greater extent of forward movement in the electrical chassis. This extensible leg, for example, comprises a first member and a second member that is telescopically received within the first member. The leg is extensible when the knee joint is in the low position. 
     The cable support platform optionally comprises a roller. In this case, the cable support surface may include the roller having alternating cylindrical segments of different radial dimensions that act as cable groomers to distribute the load of cable across the support surface, which is bounded by cable retention ears at opposite ends of the support surface. 
     A single pin may extend through the roller and the knee joints of the articulated A-frame supports. The pin provides a pivot axis for the knee joints and a roller axis for the roller. A pair of spacer bearings may be borne on the pin to a greater width than is occupied by the articulated A-frame supports. The spacer bearings may abut structure, such as the interior of a rear compartment on the chassis, to prevent wobble in the cable support platform. 
     The cable management system is mounted on a support frame, such as the support frame for the electrical system chassis. A channel may be mounted to the support frame to provide clear access for cable installation and removal beneath other chassis components. This channel may also be provided with a tool retention structure for use in retaining a cable installation tool. A T-bar assembly may also be mounted to the support frame to provide a cable stress relief structure. 
     The articulated A-frame supports may each comprise a frame for use in securing cables to the articulated A-frame supports. For example, this frame may comprise a triangle brace proximate the knee joint of the articulated A-frame support. The triangle brace may be perforated to receive cable ties, cable retention clips, and the like. 
     The cable management system is used according to a method of managing cables to facilitate movement of the electrical system chassis assisted by use of the articulated A-frame support assembly. The method comprises the steps of: 
     (a) connecting a first end of a cable with the electrical system and a second end of the cable with a locus outside the electrical system such that the cable has sufficient slack to permit extensile and de-extensile motion of the electrical system chassis with respect to the locus; 
     (b) routing the cable over the articulated A-frame support assembly during the step of connecting; and 
     (c) extending and de-extending the electrical system chassis with concomitant rising and falling of the articulated A-frame support assembly to manage the slack in the cable. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a right side elevational view of a rack-mounted cable management system; 
     FIG. 2 depicts a top, rear, left side perspective view of the cable management system installed within an electrical system chassis; 
     FIG. 3 depicts a perspective view of the cable management system removed from the electrical system chassis; 
     FIG. 4 is a left side elevational perspective view of the cable management system of FIG. 2 in a flattened configuration; 
     FIG. 5 is a perspective view demonstrating full extension of the cable management system from the position shown in FIG. 4; 
     FIG. 6 is a top, left rear perspective view of a T-bar assembly that optionally forms part of the cable management systems; and 
     FIG. 7 is a bottom, left perspective view of the T-bar assembly. 
    
    
     DETAILED DESCRIPTION 
     The following detailed description illustrates a preferred embodiment of a cable management assembly that uses articulated A-frame supports to occupy such slack in a cable as is required for extensile and de-extensile motion of an electrical system chassis that may, for example, be mounted in an electrical equipment rack. The use of a preferred example should not be construed to unduly limit the concepts that are disclosed herein because the teaching is by way of example and not by limitation. 
     FIG. 1 depicts a cable management assembly  100  that is used to manage slack residing in cable  102  over region  104 . The slack in cable  102  is sufficient to permit forward and rearward motion of an electrical system chassis  106  including extensile motion according to arrow  108  and de-extensile motion according to arrow  110 . A conventional telescoping rail assembly  112  includes a female rail member  114  that is bolted to an equipment rack  116 , and a male slide  118  that is slidingly received within the female rail member  114  and bolted to the electrical system chassis  106 . The telescoping rail assembly  112  facilitates extensile and de-extensile motion of the electrical system chassis  106  according to arrows  108  and  110 . 
     The cable management assembly  100  comprises an opposed pair of articulated A-frame support assemblies, though only one such assembly  120  is visible from the perspective of FIG.  1 . The articulated A-frame support assembly  120  comprises a first segment  122 , a second segment  124 , and a knee joint  126  coupling the first segment  122  with the second segment  124 . A cable support platform  128  is coupled with the pair of the articulated A-frame support assemblies, such as assembly  120 , to provide horizontal support for cable  102 . The knee joint  126  has a vertical range of motion over an interval  130  extending between a high position  132  and a low position  134 . 
     The rise and fall of knee joint  126  over the vertical range of motion  130  is concomitant with extensile and de-extensile motion of the electrical system chassis  106 , according to arrows  108  and  110 , as well as arcuate pivoting motion of the first segment  122  and the second segment  124  originating from the knee joint  126 . By way of example, FIG. 1 also shows a second cable management assembly  136  that is identical to cable management assembly  100 . A second chassis  138  is coupled with the second cable management assembly  136 . The second chassis  138  is extended from the equipment rack  116  further than is the electrical equipment chassis  106 , with a corresponding drop in knee joint  148  and associated pivotal opening of segments  150 ,  152  along arc  154 . Fastener  158  pivotally connects electrical system chassis  106  with first segment  122  remotely from the knee joint  126 . Fastener  156  similarly connects the second segment  124  with the equipment rack  116 . 
     A first end  160  of cable  102  is connected with the electrical system chassis  106 , for example, to a bus or other electrical component residing on the electrical system chassis  106 . A second end  162  is connected to a locus outside the electrical system chassis  106 , for example, to the second chassis  138 . The rising and falling motion of cable support platform  128  between the high position  132  and the low position  134 , concomitant with forward and rearward motion of electrical system chassis  106  according to arrows  108 ,  110 , prevents tangling of cable  102  with itself and other cables and prevents resultant damage to the cables. 
     FIG. 2 is a rear perspective view of the electrical system chassis  106  showing the cable management assembly  100  installed within a rear cavity  200 . A second articulated A-frame support assembly  202  is a mirror image of the articulated A-frame support assembly  120 . The cable support platform  128  extends horizontally between the articulated A-frame support assemblies  120 ,  202 . 
     FIG. 2 demonstrates a particularly preferred cable support platform  128  in the form of a single-piece roller  204  presenting an outboard surface  206  formed of alternating cylindrical segments  208  and  210  each having a different radial outboard dimension. Thus, the surface  206  functions as a cable grooming surface that uses the alternating cylindrical segments  208 ,  210  to even out and distribute cables, such as cables  212  and  214 , over the cable support surface  206 . Opposed cable retention ears  216 ,  218  are located at opposite ends of the cable support surface  206  to retain cables  212 ,  214  on surface  206  as platform  128  moves through its range of motion. A pair of spacer bearings  220 ,  222  occupy a greater width than is occupied by the articulated A-frame support assemblies  120 ,  202 , and prevent side-to-side wobble of the cable support assembly  100  by abutting chassis  106 . 
     A support frame  224  forms part of chassis  106  and carries an optional T-bar assembly  226 , which is used to provide cable stress relief, for example, by engaging cable  214  to reduce the strain and freedom of motion that is imposed upon cable  214  by forward and rearward motion of chassis  106 . A channel  228  is mounted to the support frame  224  to provide clear access beneath wall  230  for cable installation and removal through passageway  232 . The chassis  106  may include any number of additional features, such as a fan exhaust area  234 . Opposed rail structure  236  beneath passageway  232  is optionally used for storage of tools, such as a conventional cable installation tool. 
     The articulated A-frame support assembly  120  may comprise an optional triangular brace  238  proximate the knee joint  126 , which includes a perforation  240  capable of accepting a cable tie  242  for use in additionally restraining the freedom of motion in cable  214   
     FIG. 3 depicts the cable support system  100  from a top, side, rear perspective that reveals the first segment  122  comprising at least two members that include an elongated female receptacle  300  holding an extensible male leg  302 . The triangle brace  240  is attached to the extensible male leg  302 . A single-piece pin  304  protrudes though the roller  204 , the spacer bearings  220 ,  222 , and the respective knee joints  126 ,  306  to form a unitary axis for pivoting of the first segment  122  and the second segment  124 , as well as an axis of rotation for roller  204 . A shoe  308  provides additional reinforcement for pivoting motion of first segment  122  around fastener  310 . 
     FIG. 4 depicts the cable support assembly in a horizontally flattened configuration presenting the low height  134  for knee joint  126 . At this point, the extensible male leg  302  is fully received within female receptacle  300 , such that first segment  122  occupies a minimum extension length L 1 . FIG. 5 depicts the cable support assembly  100  in a flattened configuration with full extension of the first segment  122 . An optional hermaphroditic intermediate slide  500  is provided for receiving the extensible male leg  302  and, in turn, being received within the female receptacle  300 . The purpose of the hermaphroditic intermediate slide  500  is to provide a greater extension length L 2  than can be obtained from the female receptacle  300  and the extensible male leg  302  alone for a given minimum extension length L 2 . 
     FIG. 6 is a top rear perspective view providing additional detail with respect to the T-bar assembly  226 . A channel bracket  600  is coupled to the support frame  224  (see FIG. 2) through bolts  602 ,  604 . A handle arm  606  is pivotably connected to journal flange  608  through the use of threaded fasteners  610  to permit arcuate motion of handle arm  606  over the range indicated by arc  612 . Handle  614  comprises a pair of bars  616  with ends  618 ,  620  bent inwardly towards channel bracket  600 . A forward-extending lip  622  is used to provide additional support for the T-bar assembly  226  by residing atop support frame  224 . 
     FIG. 7 is a bottom front perspective view of the T-bar assembly  226 . Lip  622  is shown to have a tongue  700  that engages complimentary mating structure in the support frame  224  (see FIG.  2 ). The journal flange  608  engages a T-section opposite handle  614  to permit arcuate motion of handle  614  along arc  612 . 
     In operation, the cable management system  100  is used to manage cables by permitting forward and rearward movement of the electrical system chassis  106  with use of articulated A-frame support assemblies  120 ,  202 . The method of use comprises connecting the first end  160  of cable  102  with the electrical system chassis  106  and connecting a second end  162  of the cable  102  with a locus, e.g., second chassis  138 , that resides outside the electrical system chassis, such that the cable has sufficient slack to permit extensile and de-extensile motion  108 ,  110 , of the electrical system chassis  106  with respect to the locus. The cable  102  is routed over the cable support platform  128  of the articulated A-frame support assembly  102 , after which extending and de-extending the electrical system chassis  106  with concomitant rising and falling of the articulated A-frame support assembly between positions  132  and  134  manages and grooms in a comb-like fashion the slack in cable  102  over region  104 . The cable  102  may optionally be routed through passageway  232  and through the T-bar assembly  226  to provide additional support for cable  102 . Any number of cables may be used in combination with cable  102 . 
     The foregoing discussion is intended to illustrate the concepts of the invention by way of example with emphasis upon the preferred embodiments and instrumentalities. Accordingly, the disclosed embodiments and instrumentalities are not exhaustive of all options or mannerisms for practicing the disclosed principles of the invention. The inventors hereby state their intention to rely upon the Doctrine of Equivalents in protecting the full scope and spirit of the invention.