Abstract:
The present invention includes an add-on trough for use with existing telecommunications equipment racks having cable management troughs. The add-on troughs engage the outer edge of the existing troughs and permit higher densities of telecommunications circuits to be incorporated with these racks. Several alternative embodiments are adapted for mounting on either upper or lower troughs, or on lower troughs only. The troughs may incorporate a reinforcement structure as required to support the weight of cables placed within the trough without sagging. A variety of openings for telecommunications cable passage into and out of the troughs are provided. A power cable route is incorporated into the design of certain embodiments.

Description:
FIELD OF THE INVENTION 
     The present invention relates to high-density cable management racks. Specifically, the invention relates to providing increased trough space for cable management racks. 
     BACKGROUND OF THE INVENTION 
     In the telecommunications industry, one of the biggest changes has been the increase in density of circuits required to service the current demand. In some cases, previously installed equipment racks have been retrofitted to hold higher density switch panels and other modules which provide a higher density of circuits. In other installations, the overall number of equipment racks installed at a particular location has been increased to provide more circuits. Either of these approaches is effective at solving the issue of density but both have also spawned a new issue: cable management overload. 
     When the density of circuits is increased at a particular location, the number of jumpers or cross-connect cables required will also increase proportionately. Once these jumpers have been installed they are organized in troughs and channels that run horizontally and vertically across the equipment racks. These troughs were originally sized to hold a certain number of jumpers, based on the original density of the particular rack or overall installation. In the case of horizontal troughs, when the density of the rack or installation is dramatically increased, these troughs can be insufficient to handle the added number of jumpers. Overloaded troughs can cause operational and maintenance problems due to the difficulty of getting to jumpers in the now heavily loaded troughs or the troughs may physically not be able to hold the number of jumpers required by the modified installations. 
     The demand for higher density telecommunications installations shows no signs of abating in the foreseeable future and it promises to continue increasing beyond current levels. Improving the ability of current installations to be retrofitted to handle this increased demand is desirable. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is an add-on cable management trough for use with existing telecommunications equipments racks having pre-existing cable management troughs. This add-on trough has a slot which engages the outer edge of the existing fixed cable trough. The add-on trough may also include reinforcing members mounted inside the trough. The add-on trough may also have a bottom which is shorter than one or both of the sides of the trough. The add-on trough may include reinforcing legs below the bottom of the trough which rest against a portion of the rack and may have an opening in the wall of the trough to allow cables to pass from the fixed trough into the add-on trough. 
     A cable management system is provided whereby troughs are added to the outer edges of fixed troughs attached to telecommunications equipment racks. These add-on troughs can be attached to either upper or lower fixed troughs and may have openings through the walls of the trough to permit cables to enter or exit the add-on trough. Add-on troughs attached to adjacent telecommunications equipment racks cooperate to form continuous add-on cable channels. 
     A method of adding a further trough to a cable management trough fixed to a telecommunications equipment rack is also provided. 
     A variety of advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief explanation of the drawings is as follows: 
     FIG. 1 is a top perspective view of two telecommunications equipment racks with first upper and lower troughs shown mounted to the racks and add-on second troughs exploded. 
     FIG. 2 is a top perspective view of an embodiment of an add-on trough according to the present invention. 
     FIG. 3 is a top view of the trough in FIG.  2 . 
     FIG. 4 is a side view of the trough in FIG.  2 . 
     FIG. 5 is an opposite side view of the trough in FIG.  2 . 
     FIG. 6 is an end view of the trough in FIG.  2 . 
     FIG. 7 is a perspective view of the reinforcing brace included in the trough in FIG.  2 . 
     FIG. 8 is a perspective view of another embodiment of an add-on trough according to the present invention. 
     FIG. 9 is a top view of the trough in FIG.  8 . 
     FIG. 10 is a side view of the trough in FIG.  8 . 
     FIG. 11 is an opposite side view of the trough in FIG.  8 . 
     FIG. 12 is an end view of the trough in FIG.  8 . 
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     Referring now to FIG. 1, two telecommunications racks  10  are shown. Each rack  10  includes two vertical supports  13 , a base  15  with a lower face  1 , fixed upper trough  16  with a outer wall  17  with an outer edge  12  and a fixed lower trough  18  having an outer wall  19  with an outer edge  14  and a cable knockout  4  in outer wall  19 . In between troughs  16  and  18  on rack  10  could be mounted a variety of telecommunications equipment, such as cross-connect modules and jacks. Representative pieces of telecommunications equipment  5  is shown in FIG. 1 in the interest of clarity, equipment  5  being mounted to supports  13  by flanges  6  and fasteners  7  inserted through holes  8  in flanges  6  and holes  9  in supports  13 . Example telecommunications racks and equipments are shown in U.S. Pat. Nos. 5,220,600 and 6,102,214, the disclosures of which are incorporated by reference. It is anticipated that the present invention is adaptable to any telecommunications rack which includes one or more horizontal cable troughs. 
     Referring now to FIGS. 2 through 6, the details of a first add-on trough  20  in FIG. 1 are shown. An inner wall  22  has a lower edge  24 , an upper edge  26 , an inner side  28  and outer side  30 . An outer wall  32  has a lower edge  34 , an upper edge  36 , an inner side  38  and an outer side  40 . A bottom  42  has an inner edge  44 , an outer edge  46 , a upper side  48  and a lower side  50 . Tabs  52  and  54  extend from upper edge  26  of inner wall  22  and are shaped to be generally parallel to outer side  30  of inner wall  22 . Between tab  52  and outer side  30  of inner wall  22  is defined a slot  56 . Between tab  54  and outer side  30  of inner wall  22  is defined a slot  58 . Slots  56  and  58  are sized and shaped to fit over and engage outer edges  12  or  14  of fixed troughs  16  or  18  of rack  10 . Bottom  42  has a shorter overall length than outer wall  32  so as to define a pair of cable exits  60  and  62  from trough  20  when trough  20  is mounted to outer edge  12  of fixed upper trough  16 . Cable exits  60  and  62  allow cables lying within trough  20  to exit out of trough  20  vertically to be connected with telecommunications equipment mounted to rack  10 . Inner wall  22  is shown to be same length as bottom  42 . Inner wall  22  can be of greater or lesser length than bottom  42  as design or manufacturing considerations dictate. Outer wall  32  is sized to extend generally the full width of rack  10  to create a continuous outer face to the add-on trough  20  when trough  20  is mounted to fixed troughs  16  or  18 . 
     Shown mounted within a channel  64  defined by the inner sides  28  and  38  of walls  22  and  32 , and by the upper side  48  of bottom  42  are a series of internal reinforcing members  66 . Details of these reinforcing members  66  are shown in FIG.  7 . Because of the weight of the cross-connect or jumper cables that may be laid in channel  64 , reinforcing members  66  serve to provide greater rigidity and strength to trough  20  and reduce the amount of sag the weight of the cables might cause. Referring now to FIG. 7, reinforcing member is made up of three sections: outer section  68 , bottom section  70  and inner section  72 . As shown in the preceding FIGS., these sections are sized to fit inside of channel  64 . Outer section  68  is sized to fit along and be securely fastened to inner side  38  of outer wall  32 . Bottom section  70  is sized to extend across and be securely fastened to upper side  48  of bottom  42 . Inner section  72  is sized to fit along and be securely fastened to inner side  28  of inner wall  22 . The fastening of reinforcing member  66  to trough  20  within channel  64  can be accomplished by a variety of methods, such as welding, spot welding, gluing or riveting, so long as the inner surface of reinforcing member  66  remains predominately smooth. Sharp or tall distortions within channel  64  caused by the fastening method used are undesirable, since these distortions could interfere with cable movement within channel  64  or possibly cause damage to the cables within channel  64 . The number and spacing of reinforcing members  66  required in a particular trough  20  will vary based on the nature and thickness of the material used to make trough  20  and members  66 , and the number and weight of cables expected to be placed within channel  64 . The four members  66  shown as part of trough  20  in FIGS. 2 through 7 are illustrative only. 
     Referring now to FIGS. 8 through 12, the details of a second add-on trough  120  in FIG. 1 are shown. An inner wall  122  has a lower edge  124 , an upper edge  126 , an inner side  128  and an outer side  130 . An outer wall  132  has a lower edge  134 , an upper edge  136 , an inner side  138  and an outer side  140 . A bottom  142  has an inner edge  144 , a outer edge  146 , a upper side  148  and a lower side  150 . Tabs  152  and  154  extend from upper edge  126  of inner wall  122  and are shaped to be generally parallel to outer side  130  of inner wall  122 . Between tab  152  and outer side  130  of inner wall  122  is defined a slot  156 . Between tab  154  and outer side  130  of inner wall  122  is defined a slot  158 . Slots  156  and  158  are sized and shaped to fit over and engage the outer edges  12  or  14  of fixed troughs  16  or  18  of rack  10 . Extending through inner wall  122  is a cable opening  160 . Cable opening  160  permits cables exiting from cable knockout  4  in outer wall  19  of lower fixed trough  18  to enter channel  164  defined by the inner sides  28  and  38  of walls  22  and  32 , and by the upper side of bottom  42 . 
     Extending below lower side  152  of bottom  142  are reinforcing legs  166 . Because of the weight of the cross-connect or jumper cables that may be laid in channel  164 , reinforcing legs  166  serve to provide greater rigidity and strength to trough  120  and reduce the amount of sag the weight of the cables might cause. Each reinforcing leg  166  includes a power cable opening  162  and a flange  168 . Power cable opening  162  allows power cables to organized or managed as they pass across rack  10  and provide power to telecommunications equipment mounted on rack  10  but also keeps these power cables separate from the jumpers or cross-connect cables. Flanges  168  include fastener holes  170  and extend from legs  166  and provide a flat surface which rests against and is supported by lower face  11  of base  15  of rack  10 . As shown, trough  122  is adapted to be mounted to the outer edge  14  of lower fixed trough  18  with flanges  162  resting against face  11 . Optionally fasteners can be inserted through holes  170  into lower face  11  to secure trough  120  to fixed trough  18 . Alternatively, trough  122  can be fastened more securely to rack  10  by engaging outer edge  14  with slots  156  and  158  and then inserting fasteners such as screws through flanges  168  into face  11 . As a further alternative, legs  166  can be made without flanges  168 . 
     As shown in the Figures, sides  32 ,  122  and  132  and bottom  142  are all approximately the same length and all extend generally the full width of rack  10 . 
     The reinforcement design of trough  20  as shown with members  66  mounted within channel  64  is adapted for use with both upper and lower troughs, since there is not structure extending below bottom  42  which might interfere with telecommunications equipment mounted in rack  10 . The reinforcement design of trough  120  with members  166  extending below bottom  142  is adapted principally for use with a lower trough, where a lower face is located beneath the fixed trough for flanges  168  to rest upon and where no telecommunications equipment will be mounted beneath the trough. In certain rack configurations, these conditions may also exist with respect to an upper trough as well, allowing trough  120  as shown to be mounted to an upper trough. Alternatively, trough  120  could be adapted by eliminating legs  166  and using the internal reinforcement design of trough  120 . Then trough  120  would be suitable for use with an upper trough where vertical cable access, such as provided by openings  60  and  62 , is not required. 
     With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of parts without the scope of the present invention being narrowed. It is intended that the specification and depicted aspects be considered exemplary only, with the true scope and spirit of the invention being indicated by the broad meaning of the following claims.