Abstract:
A secure cable trough includes a tray, a retaining member, and an adjustable fastening mechanism. The tray includes a first retaining arm. The retaining member includes a second retaining arm. The retaining member is slideably engaged to the tray. The first retaining arm, the second retaining arm, the tray, and the retaining member define a cavity for housing the cables. The first retaining arm and the second retaining arm extend toward each other and are offset and overlapping. The distance between the first and second retaining arm defines a gap. The gap provides access to cables and allows cables to be inserted and extracted from the trough. The first and second retaining arms inhibit cables housed within the trough from inadvertently falling out. The adjustable fastening mechanism slideably engages and locks the retaining member to the tray. The adjustable fastening mechanism allows the retaining member to be positioned relative to the tray. The size of the gap is proportional to the relative position between the tray and the retaining member.

Description:
FIELD OF THE INVENTION 
     The present invention relates to wiring troughs, and specifically to a wiring trough for accessing and securely housing and protecting telecommunications equipment. 
     BACKGROUND 
     Typically, wire troughs are used to house cables routed between various locations, such as routing telecommunication cables between a building entrance protector (BEP) and a building, or between floors of a building. For example, a BEP may provide an interface for cables from a central office of a service provider for distribution throughout the building served by the BEP. Numerous wires and cables typically protrude through the walls of the BEP. To accommodate an uncertain number of cables and wires, troughs are used for retaining and routing the cables and wires. 
     Enclosures and troughs are often located in accessible areas, such as basements, closets, and offices. Thus, it is desirable to control access to the cables, to prevent acts such as wire tapping, vandalism, and inadvertent damage to the cables. Typical troughs comprise permanent openings on one side of the trough to allow wires and cables to be inserted and removed from the trough. However, this design allows anyone, whether authorized or not, access to the cables. Thus, there is a need for a secure trough for providing access to authorized persons only. 
     SUMMARY OF THE INVENTION 
     In one embodiment of the invention, a secure cable trough includes a tray, a retaining member, and an adjustable fastening mechanism. The tray includes a first retaining arm. The retaining member includes a second retaining arm. The retaining member is slideably engaged to the tray. The first retaining arm, the second retaining arm, the tray, and the retaining member define a cavity for housing at least one cable. The first retaining arm and the second retaining arm extend toward each other, are offset and overlapping, and create an adjustable gap. The gap provides access to cables and allows cables to be inserted and extracted from the cavity. The first and second retaining arms inhibit cables housed within the cavity from inadvertently falling out of the cavity. The adjustable fastening mechanism slideably engages and locks the retaining member to the tray. The adjustable fastening mechanism provides for the definition of a relative position between the tray and the retaining member. The size of the gap is in response to the relative position between the tray and the retaining member. 
     In another embodiment of the invention, a method for accessing and securely retaining cables in a cavity defined by a tray and a retaining member includes loosening an adjustable fastening mechanism for slideably engaging the retaining member to the tray. The tray comprises a first retaining arm. The retaining member comprising a second retaining arm. The first retaining arm and the second retaining arm extend toward each other. The first retaining arm and the second retaining arm are offset and overlapping, and create an adjustable gap. The method also includes positioning the retaining member relative to the tray to provide the gap sufficient to allow insertion and extraction of cables into and out of the cavity. The method includes performing at least one of inserting and extracting at least one cable into and from the cavity. The method includes positioning the retaining member relative to the tray to provide the gap sufficient to inhibit cables housed within the cavity from inadvertently falling out of the cavity. The method includes locking the adjustable fastening mechanism to secure cables housed with the cavity. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The invention is best understood from the following detailed description when read in connection with the accompanying drawing. The various features of the drawings may not be to scale. Included in the drawing are the following figures: 
     FIG. 1A is a top view of an exemplary secure trough and a closed building entrance protector (BEP) in accordance with the present invention; 
     FIG. 1B is a front view of FIG. 1A with the BEP open; 
     FIG. 2 is an exploded top view of an exemplary trough in accordance with the present invention; 
     FIG. 3A is a side view of an exemplary embodiment of trough having a minimum width gap, in accordance with the present invention; 
     FIG. 3B a front view of the trough in FIG. 3A; 
     FIG. 4A is a side view of an exemplary embodiment of trough having a maximum width gap, in accordance with the present invention; 
     FIG. 4B front view of the trough in FIG. 4A; and 
     FIG. 5 is an exemplary flow diagram of a process for securely retaining cables in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     Access to a trough may be controlled by the type of mechanism used to hold together the parts of the trough. Fastening mechanisms may comprise special security screws to securely lock the trough, thereby restricting access to only those individuals who have special tools designed to remove those security screws. Two such types of security screws are 216-type screws and KS-type screws. KS-type screws and 216-type screws are described in U.S. Pat. No. 5,913,650, issued to Daoud. A regular slotted-head screw, Phillips-head screw, Allen screw, or bolt may also be used to lock the enclosure. 
     FIG. 1A is a top view of an exemplary secure trough  10  and a closed building entrance protector (BEP)  2  in accordance with the present invention. FIG. 1B is a front view of FIG. 1A with the BEP  2  open. BEP  2  comprises a cover  6  and a base  4 . Access to the portion of cables  8  within BEP  2  is achieved by opening cover  6 . Typically, cover  6  is securely fastened to base  4 , and a technician uses a tool (e.g., screwdriver, wrench, KS-type tool, 216-type tool) to unlock the cover  6 . BEP  2  is typically mounted to a wall or equipment cabinet. 
     Secure trough  10  provides a secure (e.g., lockable) cable guide for routing cables  8  to various locations, such as other BEPs, other portions of a building, and out of or into a building. Secure trough  10  comprises a tray  14  and a retaining member  12 . Retaining member  12  is slideably engaged with tray  14  to allow retaining member  12  to slide up and down in the directions of arrow  25  with respect to tray  14 . The tray  14  comprises several retaining arms  18  and retaining member  12  comprises several retaining arms  16 . The tray  14 , retaining member  12 , and retaining arms  16  and  18  form a cavity  23  for housing the cables  8 . Cables  8  are positioned within cavity  23  and routed to various desired locations. In alternate embodiments of the invention, trough  10  is mounted to either a wall, to BEP  2 , or both, by any appropriate means known in the art such as bolt mounted, screw mounted, riveted, anchored, adhesively mounted, or combination thereof. Mounting of trough  10  to a wall is facilitated by openings  21  and to BEP  2  by openings  20 . 
     Access to cables  8  housed within trough  10  is achieved by adjusting the gap  40  between retaining arms  16  and  18 . Retaining arms  16  and  18  are offset and overlap to form gap  40 . Widening gap  40  allows access to cables  8  within trough  10  to perform activities such as cable maintenance and repair, inserting cables into trough  10 , and extracting cables  8  from trough  10 . Reducing gap  40  tends to prevent tampering of cables  8  by limiting access to cables  8  housed in trough  10 . Also, reducing gap  40  tends to prevent cables  8  retained in trough  10  from inadvertently falling out of the cavity  23 . Retaining arms  16  and  18  may be flexible to facilitate access to cables  8  housed in trough  10 , but flexibility is not a requirement. Retaining arms  16  and  18  may also be rigid without hampering the functionality of trough  10 . 
     Retaining member  12  is slideably attached to tray  14  by fastening mechanism  24 . Fastening mechanism  24  is loosened to facilitate sliding of retaining member  12 . Fastening mechanism  24  is tightened (e.g., locked) to fix the relative position of retaining member  12  with respect to tray  14  and accordingly fix the width of gap  40 . Fastening mechanism  24  attaches retaining member  12  to tray  14  through slotted counter sink  28  and slotted open channel  26 . Retaining member  12  may be slid upward, in the direction of the upper arrowhead of arrow  25 , until the bottom  27  of slotted open channel  26  contacts fastening mechanism  24 . At this point, gap  40  is at its maximum width. Retaining member  12  may be slid downward, in the direction of the bottom arrowhead of arrow  25 , until the top  29  of slotted open channel  26  contacts fastening mechanism  24  (top  29  of slotted open channel  26  is hidden from view by fastening mechanism  24  in FIG.  1 B). At this point, gap  40  is at its minimum width. 
     BEP  2  is an example of one type of enclosure that may be used with secure trough  10 . Other types of enclosures having cables protruding through their walls may be used. Cables  8  may be any of various types of cables such as fiber optic cables, twisted pairs of copper wires, cables comprising other electrically conductive materials (e.g., ceramic, other conductive metals), or any combination thereof. Although the figures herein depict trough  10  comprising several pairs of retaining arms  16  and  18 , in an alternate embodiment of the invention, trough  10  comprises a single pair of retaining arms  16  and  18  without compromising functionality. 
     FIG. 2 is an exploded top view of an exemplary trough  10  in accordance with the present invention. Retaining member  12  comprises slotted countersink  28  having a slotted open channel  26 . Fastening mechanism  24  comprises shaft  32  and head  34 . The diameter of head  34  is larger than the diameter of the shaft  32 . The width of the slotted countersink  28  is larger than the diameter of the head  34  thus allowing fastening mechanism  24  to be recessed in the countersink  28  such that head  34  is flush with the outer edges  33 . Although, in alternate embodiments of the invention head  34  is not flush with edges  33 , such that head  34  protrudes beyond edges  33  or head  34  is recessed more deeply into slotted countersink  28 . The width of the slotted open channel  26  is smaller than the diameter of the head  34  and is larger than the diameter of the shaft  32 . Thus, fastening mechanism  24  is inserted into slotted countersink  28 , with shaft  32  protruding through slotted open channel  26 . Tray  14  comprises receiving portion  36 . To fasten retaining member  12  to tray  14 , the shaft  32  of fastening mechanism  24  is engaged with receiving portion  36 . In an exemplary embodiment of the invention, receiving portion  36  is threaded to receive threaded shaft  32 . 
     In an alternate embodiment of the invention, tray  14  comprises female portion  44  having rails  46 , and retaining member  12  comprises male portion  48  having slots  50 . Retaining member  12  is slideably engaged with tray  14  by inserting male portion  48  into female portion  44 . Male portion  50  and female portion  44  are conformally fitted to allow rails  46  to ride within slots  50 . Thus, in alternate embodiments of the invention, trough  10  comprises male portion  48  and female portion  44  without fastening mechanism  24 , trough  10  comprises fastening mechanism  24  without male portion  48  and female portion  44 , and trough  10  comprises fastening mechanism  24 , male portion  48 , and female portion  44 . 
     Fastening mechanism  24  may be any type of fastening mechanism capable of slideably attaching retaining member  12  to tray  14 . For example, fastening mechanism may be a bolt, a slotted head screw, a Phillips head screw, or a security screw. Security screws, as know in the art, require a special tool compatible with the security screw to disengage and lock the fastening mechanism. Examples of security screws include KS-type screws and 216-type screws. The use of a security screw provides security by preventing access to cables housed in trough  10  unless the person attempting access has a compatible tool. 
     FIGS. 3A and 3B are a side view and a front view, respectively, of an exemplary embodiment of trough  10  having a minimum width gap  40 , in accordance with the present invention. In FIGS. 3A and 3B, retaining member  12  is positioned such that the top  29  of slotted open channel  26  is in contact with fastening mechanism  24 . This relative positioning between tray  14  and retaining member  12  results in gap  40  being at its minimum width. In an exemplary embodiment of the invention, retaining arms  16  and  18  touch, thus reducing the width of gap  40  to zero. Retaining arms  16  and  18  are not required to touch for trough  10  to securely retain cables  18 . Trough  10  may be fabricated to provide any desired minimal gap width. This minimum gap width is obtained when fastening mechanism  24  is in contact with the top  29  of slotted open channel  26 . 
     FIGS. 4A and 4B are a side view and a front view, respectively, of an exemplary embodiment of trough  10  having a maximum width gap  40 , in accordance with the present invention. In FIGS. 4A and 4B, retaining member  12  is positioned such that the bottom  27  of slotted open channel  26  is in contact with fastening mechanism  24 . This relative positioning between tray  14  and retaining member  12  results in gap  40  being at its maximum width. Trough  10  may be fabricated to provide any desired maximum gap width. This maximum gap width is obtained when fastening mechanism  24  is in contact with the bottom  27  of slotted open channel  26 . 
     Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention. 
     FIG. 5 is an exemplary flow diagram for a process of securely retaining cables  8  in trough  10  in accordance with the present invention. In step  54 , adjustable fastening mechanism  24  is loosened to allow retaining member  12  to be slideably positioned with respect to tray  14 . The adjustable fastening mechanism  24  may be loosened with any compatible tool, such as a Phillips head screwdriver, a slotted head screwdriver, an Allen wrench, a fixed or adjustable wrench, a ratchet, a security screw tool (e.g., KS-type screw tool, 216-type screw tool), or any combination thereof. Retaining member  12  is positioned, which also positions retaining arms  16  and  18 , to adjust the width of gap  40  sufficiently to allow access to cables  8  (step  56 ). Depending upon the nature of the tasks to be performed, fastening mechanism  24  may be tightened to fix the width of gap  40  (step  58 ). If the task to be performed is, for example, a simple visual inspection of the cables  8  in trough  10 , retaining member  12  may be held in place by hand during the visual inspection, thus not requiring tightening of fastening mechanism  24 . If the task to be performed is more complex, fastening mechanism  24  may be tightened by any appropriate means (e.g., compatible tool, by hand) to fix the width of gap  40 . The tasks are performed in step  60 . The tasks may comprise any combination of maintenance, repair, or inspection of cables  8  and/or trough  10 , and insertion and/or extraction of cables from trough  10 . If fastening mechanism  24  was tightened to perform the tasks, then fastening mechanism  24  is loosened by any appropriate means in step  62 . Retaining member  12  is positioned, which in turn positions retaining arms  16  and  18 , to adjust the width of gap  40  sufficient to secure cables  8  in trough  10  in step  64 . Fastening mechanism  24  is locked by any appropriate means, such as a compatible tool, in step  66 . 
     Retaining cables  8  in secure trough  10  prevents unauthorized access of cables  8  retained in trough  10 . Authorized access is available only to persons having a tool compatible with fastening mechanism  24 . Prevention of unauthorized access tend to prevent tampering of the cables  8  retained in trough  10 , such as wire tapping, and vandalism. Further, various size cables or bundles of cables can be accommodated by trough  10 , simply by adjusting the width of gap  40 . 
     Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.