Patent Publication Number: US-7715680-B2

Title: Cable management drawer with access panel

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation of application Ser. No. 11/640,477, filed Dec. 15, 2006 now U.S. Pat. No. 7,418,182; which is a continuation-in-part of application Ser. No. 11/546,538, filed Oct. 10, 2006 now U.S. Pat. No. 7,437,049; which applications are incorporated herein by reference. 

   TECHNICAL FIELD 
   This disclosure relates generally to methods and devices for managing telecommunication cables. More particularly, this disclosure relates to a cable management panel having a sliding drawer for managing fiber optic cables. 
   BACKGROUND 
   Cable management arrangements for cable termination, splice, and storage come in many forms. One type of cable management arrangement used in the telecommunications industry includes sliding drawers installed on telecommunication equipment racks. The drawers provide organized, high-density, cable termination, splice, and storage in telecommunication infrastructures that often have limited space. 
   To accommodate the massive scale of telecommunication infrastructures, and to maximize use of limited space, the drawers are sometimes stacked or mounted at heights above a comfortable working height. That is, the drawers can be stacked such that it is difficult to reach or access the interior of some drawers. Access is necessary in both the original installation of cables and subsequent adaptation or maintenance of the cables. There is a continued need in the art for better cable management devices and arrangements to address concerns regarding the ease of use of such cable management arrangements. 
   SUMMARY 
   The present disclosure relates to a cable management panel having a chassis and a slidable drawer. The slidable drawer has a tray on which cable management devices are mounted. The tray is pivotally mounted to a drawer frame of the drawer. Access to the cable management devices is provided by sliding the drawer out from the chassis, and pivoting the tray from a non-pivoted position to a pivoted position. The tray locks in place in both the non-pivoted position and the pivoted position. 
   A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. 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 claimed invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of one embodiment of a cable management panel according to the principles of the present disclosure, having a drawer that is shown in an open position; 
       FIG. 2  is a front elevation view of the cable management panel of  FIG. 1 , shown with the drawer in a closed position; 
       FIG. 3  is a side elevation view of the cable management panel of  FIG. 1 ; 
       FIG. 4  is a side elevation view of the cable management panel of  FIG. 3 ; shown with a tray of the drawer in a pivoted position; 
       FIG. 5  is a front perspective view of the cable management panel of  FIG. 4 ; 
       FIG. 6  is a front elevation view of the cable management panel of  FIG. 5 ; 
       FIG. 7  is a partially exploded, front perspective view of the cable management panel of  FIG. 5 ; 
       FIG. 8  is an enlarged detail view of  FIG. 7 ; 
       FIG. 9  is an enlarged perspective view of a portion of the cable management panel of  FIG. 1 ; 
       FIG. 10  is front elevation view of the cable management panel of  FIG. 1 , shown in an application wherein the panel is vertically mounted; 
       FIG. 11  is a front elevation view of the cable management panel of  FIG. 10 , shown with the drawer in an open position, and the tray of the drawer in a pivoted position; 
       FIG. 12  is an enlarged detail view of  FIG. 7 , schematically representing an alternative biasing arrangement of the cable management panel; 
       FIG. 13  is a partially exploded, front perspective view of another embodiment of a cable management panel, according to the principles of the present disclosure; 
       FIG. 14  is an enlarged detail view of  FIG. 13 ; 
       FIG. 15  is an enlarged perspective view of a portion of the cable management panel of  FIG. 13 ; and 
       FIG. 16  is a schematic representation of a portion of a connection arrangement shown in  FIG. 15 . 
   

   DETAILED DESCRIPTION 
   Reference will now be made in detail to various features of the present disclosure 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 to  FIG. 1 , a cable management panel or module  10  according to the present invention is shown. The panel  10  includes a frame or chassis  12  having mounting brackets  14 . The mounting brackets  14  are used to mount the panel  10  to a telecommunication structure, such as a telecommunication rack or frame. The cable management panel  10  can also be configured for mounting within a cabinet or enclosure, for example. Details of an example mounting bracket arrangement that can be used in accordance with the principles disclosed are described in U.S. Publication No. 2005/0025444, the disclosure of which is incorporated herein by reference. 
   The chassis  12  of the cable management panel  10  has a front  16 , opposite sides  18 , and a rear  20 . The sides  18  define cable access openings  22  (see also  FIG. 3 ) through which cables are routed into or out from the chassis  12 . The chassis  12  further includes a drawer  26  that slides between an open position ( FIGS. 1 and 3 ) and a closed position ( FIG. 2 ). In the closed position, cables contained within an interior region  24  of the drawer  26  are enclosed and protected. In the open position, the cables can be accessed for maintenance purposes, for example. 
   Referring still to  FIG. 1 , the drawer  26  of the cable management panel  10  includes a front  33 , a rear  34 , a bottom tray (e.g., base plate or panel)  36 , and sides  38 . The sides  38  and rear  34  of the drawer generally define a drawer frame  46  to which the bottom tray  36  is attached. The front  33  of the drawer  26  is defined by an upright front drawer panel  40  that is attached to the tray  36 . The upright front drawer panel  40  encloses the interior region  24  of the drawer  26  when the drawer is in the closed position. While the sides  38  of the drawer  26  are open, the sides  18  of the chassis are constructed to enclose the interior region  24  of the drawer  26  when the drawer is in the closed position. 
   The open sides  38  of the drawer  26  are provided to allow for cable entry and exit, and prevent cable damage during sliding movement of the drawer  26 . Radius limiters  58  are located at the sides  38  of the drawer  26  for managing the exiting and entering cables during sliding movement of the drawer. The radius limiters  58  also act as guides for cables passing through the access openings  22 , and protect the cables from damage by limiting cable bending beyond a minimum bend radius. 
   The open sides  38  of the drawer  26  are generally defined by horizontal side plates  42 . The side plates  42  include longitudinal slots  52 . The longitudinal slots  52  cooperate with the radius limiters  58  on each side of drawer  26 . Preferably, the radius limiters  58  are moveably mounted relative to the chassis  12  and drawer  26 . In one embodiment, movement of the radius limiters  58  is controlled in a synchronized manner relative to the movement of the drawer  26 . Further details of example drawers having radius limiters, and drawers having radius limiters with synchronized movement are described in U.S. Pat. Nos. 6,438,310; 6,504,988; and 7,079,744; the disclosures of which are each incorporated herein by reference. 
   The drawer  26  in the illustrated embodiment includes a variety of cable management elements  60  (e.g., cable management components or structures and distribution components or devices). The interior region  24  of the drawer  26  is sized for receiving the cable management elements  60 . When the drawer  26  is in the closed position, the cables and cable management devices or elements  60  in the interior region  24  are protected. 
     FIG. 1  illustrates one tray embodiment having various types of cable management elements  60 . The elements  60  include cable retainers  62 , a splice tray enclosure  64  housing splice trays, and adapters or connector holders  66  at which fiber optic connectors are mounted or located. As can be understood, the drawer  26  can be customized to include numerous forms of cable management elements  60  to accommodate the particular needs of the user. In addition to those elements  60  shown, examples of other cable management elements include other constructions, assemblies, and devices for storing the cables or connecting the cables to other cables; and/or other fiber optic devices, such as attenuators, couplers, switches, wave divisions multiplexers (WDMs), and splitters/combiners. Each of the references previously incorporated herein by reference, as well as U.S. application Ser. No. 11/196,523, which is incorporated herein by reference, describe other examples of customized element arrangements that can be provided in accordance with the principles disclosed. 
   The drawer  26  of the present cable management panel  10  slides relative to the chassis  12  via two drawer slide assemblies  28  (see also  FIGS. 6 and 9 ). The drawer slide assemblies  28  are located adjacent to the opposite sides  18  of the chassis  12 . Latches  30  are provided adjacent to both sides  38  of the drawer  26 . The latches  30  secure the drawer  26  in the closed position by engaging a side hole  32  ( FIG. 3 ) located at the side  18  of the chassis  12 . 
   In the illustrated embodiment, the two drawer slide assemblies  28  each include three slide rails. Further details of one type of slide assembly that can be used are described in U.S. Publication No. 2005/0025444; previously incorporated herein by reference. Other slide assemblies that can be used are described in U.S. application Ser. No. 11/543,457; which application is also incorporated herein by reference. 
   The illustrated drawer slide assemblies  28  each include a stop arrangement (not shown). The stop arrangement limits the opening sliding movement of the drawer  26  beyond the open position to prevent inadvertent separation from the chassis  12 . In the illustrated embodiment, the stop arrangement is an integral function of the drawer slide assembly  28 . Further details of such an arrangement are described in U.S. Publication No. 2005/0025444; previously incorporated herein by reference. 
   Referring now to  FIGS. 1 and 3 , the drawer  26  has a drawer depth D 1  ( FIG. 3 ) that extends between the front  33  ( FIG. 1 ) of the drawer and the rear  34  of the drawer. The tray  36  has a tray depth D 2  ( FIG. 3 ) that extends a majority of the depth D 1  of the drawer  26 . In the illustrated embodiment, the depth D 2  of the tray extends a substantial majority of the depth D 1  of the drawer  26 . 
   In the present cable management panel  10 , the tray  36  can be selectively pivoted from a first planar orientation, as shown in  FIG. 1 , to a second non-planar orientation, as shown in  FIG. 4 . The second “non-planar” orientation is an orientation that is “not co-planar” with the plane defined by the tray  36  when the tray is in a non-pivoted position, i.e. the first planar orientation. In one application, the tray  36  of the drawer  26  is oriented in a generally horizontal orientation, as shown in  FIG. 3 . The tray  36  can be selectively pivoted to a non-horizontal orientation, when the drawer is in the open position, to provide access to the cable management elements  60  mounted on the tray. 
   Referring now to  FIGS. 4 and 5 , the tray  36  is constructed to selectively hinge or pivot about an axis X-X ( FIG. 5 ), as represented by arrow A ( FIG. 4 ). A hinge or pivot mechanism  44  ( FIG. 5 ) that connects the tray  36  to the rear  34  of the drawer defines the axis X-X. In the illustrated embodiment, the hinge  44  is arranged such that tray  36  pivots in a direction away from the frame  46  (e.g., the side plates  42 ) of the drawer  26 . The pivoting tray  36  provides adaptable access to, for example, the connector holders  66  or connector locations, or other elements  60 , mounted on the tray. 
   Referring still to  FIGS. 4 and 5 , the drawer  26  of the cable management panel  10  includes a connection arrangement  70  that limits the pivotal movement of the tray  36  relative to the frame  46  of the drawer  26 . In the illustrated embodiment, the connection arrangement  70  is a pin and slide connection that releaseably locks the tray  36  in both the non-pivoted position ( FIG. 3 ) and a pivoted position ( FIG. 4 ). 
   Referring to  FIGS. 7 and 8 , the connection arrangement  70  generally includes a linkage or lever arm  72  and a pin assembly  76 . The lever arm  72  has a first end  78  and a second end  80 . As shown in  FIG. 6 , the first end  78  of the lever arm  72  is pivotally attached to a flange  82  of the side plate  42  of the drawer  26  (see also  FIG. 5 ). The lever arm  72  is also slidably attached to the tray  36  adjacent to the second end  80  of the arm. That is, the lever arm  72  defines a slide or slot  74  that cooperates with the pin assembly  76  to provides a pin and slot connection between the tray  36  and the drawer frame  46 . 
   Referring now to  FIG. 8 , the pin assembly  76  of the connection arrangement  70  includes a bushing or plug body  86  having a first smaller diameter portion  102  and a second larger diameter portion  104 . The plug body  86  is mounted on a pin  84 , which is attached or affixed to the tray  36 . A lock nut  88 , for example, can be used to secure the plug body  86  to the pin  84 . 
   Still referring to  FIG. 8 , the connection arrangement  70  also includes a lock piece  90 . The lock piece  90  is secured to the second end  80  of the lever arm  72 . While in the illustrated embodiment, the lock piece  90  is a separate piece from that of the lever arm  72 , it is contemplated that the lock piece can be an integral construction of the lever arm. In use, the pin assembly  76  functions to releaseably lock the tray  36  in the pivoted position, while the lock piece  90  functions to releaseably lock the tray  36  in the non-pivoted position. 
   In the illustrated embodiment, the lever arm  72  of the connection arrangement  70  is flexibly constructed. The lever arm  72  can be constructed of spring steel, for example, or in the alternative, can be of a molded construction. The slot  74  of the lever arm  72  has a slide portion  96  and an end portion  98 . The slide portion  96  of the slot  74  corresponds in size to the smaller diameter portion  102  of the plug body  86  of the pin assembly  76 . The end portion  98  of the slot  74  corresponds in size to the larger diameter portion  104  of the plug body  86 . 
   In the illustrated embodiment, the second end  80  of the lever arm  72  is a biased end having a formed angular construction that acts as a leaf-type spring. In one embodiment, the lever arm  72  is angled in a region  106  at an approximate 2 degree offset from the first end  78  of the arm. 
   In  FIG. 9 , the drawer  26  is shown in the open position with the tray  36  in the non-pivoted position. The tray  36  is locked in this non-pivoted position via the lock piece  90 . In particular, the lock piece  90  engages a corresponding aperture or hole  92  (see also  FIG. 5 ) formed in the flange  82  of the side plate  42  to lock the tray  36  in the non-pivoted position. In the position shown in  FIG. 9 , the biased end  80  of the lever arm  72  is flexed inward toward the tray  36  of the drawer  26 , and retained by the larger diameter portion  104  ( FIG. 8 ) of the pin assembly  76 . That is, in the position shown, the biased end  80  of the lever arm  72  is squeezed or moved inward toward the tray  36 , as only the smaller portion diameter  102  of the pin assembly  76  fits within the slide portion  96  of the slot  74 . The larger diameter portion  104  of the pin assembly prevents the biased end  80  from springing back or moving outward from the tray  36 . The lock piece  90  at the biased end  80  of the lever arm  72  is thereby also retained in position, i.e., in engagement with the hole  92  so that the tray  36  remains locked in the non-pivoted position. 
   The flexible construction of the lever arm  72 , however, permits a technician to release the tray  36  from the locked non-pivoted position by flexing the lever arm  72  outward from the tray  36 . The lever arm is, in essence, flexed around the larger diameter portion  104  of the pin assembly  76  in a direction away from the flange  82  of the side plate  42 . An angled tab  94  is provided at the second end  80  of the arm to assist the technician in grasping and flexing the lever arm. The outward flexure of the lever arm  72  disengages the lock piece  90  from the aperture  92 . 
   When the lock piece  90  is disengaged from the aperture  92 , the tray  36  can be pivoted to the pivoted position shown in  FIG. 5 . While pivoting the tray  36 , the smaller diameter portion  102  of the plug body  86  slides within the slide portion  96  of the slot  74 . Pivoting motion of the tray  36  is limited at a point where the pin assembly  76  seats within the end portion  98  of the slot  74 . In some embodiments, the connection arrangement  70  can be designed to permit the tray  36  to pivot between about 0 degrees and 60 degrees relative to the non-pivoted position. In the illustrated embodiment, the tray  36  pivots approximately 45 degrees relative to the non-pivoted position. 
   When the tray reaches the pivoted position, the tray  36  automatically locks into place. That is, in the pivoted position, the biased end  80  of the lever arm  72  is no longer constrained by the plug body  86 . Instead, as shown in  FIG. 6 , the end portion  98  of the slot  74  now moves laterally outward to position about or engage the larger diameter  104  of the plug body. The lateral outward movement is caused by the biased construction of the flexible arm. Because the slide portion  96  of the slot  74  is sized to receive only the smaller diameter portion  102  of the pin assembly  76 , the tray  36  is thereby locked in the pivoted position. This is desirable during installation and maintenance procedures as the technician will be, for example, pulling on cables attached to the tray. 
   In an alternative embodiment, the tray  36  can automatically lock into the pivoted position via a spring assembly. For example, as schematically represented in  FIG. 12 , the end portion  98  of the slot  74  of the lever arm  72  can be biased outward by a spring  108 . In this embodiment, the spring  108  is retained about the pin body  84  attached to the tray  36 ; and a washer  110  is positioned between the spring  108  and the lever arm  72 . The spring  108  can assist in laterally biasing the angled lever arm  72  or can solely provide the biasing force onto a non-angled lever arm. 
   Referring back to  FIGS. 6 and 9 , to release the tray from the locked position, the lever arm  72  is simply flexed inward toward the tray  36  such that the slot  74  aligns with the smaller diameter portion  102  of the plug body  86 . The smaller diameter portion of the plug body  86  then slides upward within the slide portion  96  of the slot  74  as the tray  36  is pivoted back to the non-pivoted position. 
   Upon returning the tray  36  to the non-pivoted position, a ramped surface  100  (see  FIGS. 6 and 8 ) of the lock piece  90  contacts an edge  106  ( FIG. 7 ) of the flange  82  of the side plate  42 . The ramped surface  100  acts as a guide to ease the engagement between the side plate  42  and the lever arm  72 . As the tray  36  is further pivoted, the lock piece  90  seats within the aperture  92  formed in the flange  82  to automatically lock the tray  36  in the non-pivoted position. 
   In general, the present cable management panel  10  provides adaptable access to cable management elements protected within the panel. What is meant by adaptable is that the present cable management panel  10  can be used simply as a drawer that slides in and out of the chassis, or can be used by employing the features of the pivoting tray, as described above. The pivoting tray feature is particularly convenient in applications where the panel  10  is stacked upon other panels (as schematically represented in  FIG. 4 ) or mounted above a comfortable working height. With the present panel  10 , the technician can more easily access higher mounted panels by simply sliding the drawer out from the chassis  12 , and pivoting the drawer bottom or tray  36  downward. In the pivoted position, the cable management elements  60  mounted on the pivoted tray  36  are more easily accessed as the bottom of the drawer  26  (i.e. the tray  36 ) now faces the technician. 
   Referring now to  FIGS. 10 and 11 , in an alternative application, the cable management panel  10  can be vertically mounted such that the drawer  26  and tray  36  are oriented in a generally vertical orientation. To access the interior region  24  of the drawer  26 , the technician simply slides the drawer  26  out from the chassis  12 , and pivots the chassis either to the right, or to the left (as shown by arrow B in  FIG. 11 ), depending upon the vertical orientation of the panel  10 . This arrangement is convenient in applications where lateral space, i.e., space located adjacent to the panels, is limited. Instead of standing along side the drawer  26  to face the interior region  24 , or twisting sideways to access the elements  60  in the interior region  24 , the technician can instead stand in front of the drawer and pivot the vertical tray  36  such that the interior region  24  of the drawer  26  forwardly faces the technician. 
   Referring now to  FIG. 13 , another embodiment of a cable management panel  210  is illustrated. The cable management panel  210  is similar to the panel  10  of  FIGS. 1-9 , with the exception of the connection arrangement that limits the pivotal movement of the tray relative to the frame of the drawer. 
   Similar to the previous embodiment, the cable management panel  210  includes a chassis  212  and a drawer  226 . The drawer  226  of the cable management panel  210  has a front  233 , a rear  234 , a bottom tray (e.g., base plate or panel)  236 , and sides  238 . The sides  238  and rear  234  of the drawer generally define a drawer frame  246  to which the bottom tray  236  is attached. The front  233  of the drawer  226  is defined by an upright front drawer panel  240  that is attached to the tray  236 . The upright front drawer panel  240  encloses an interior region  224  of the drawer  226  when the drawer is in the closed position. Also similar to the previous embodiment, in the present cable management panel  210 , the tray  236  can be selectively pivoted from a first planar orientation, as shown in  FIG. 15 , to a second non-planar orientation, as shown in  FIG. 13 . 
   Referring still to  FIG. 13 , the present panel  210  has a connection arrangement  270  different from that of the previous embodiment. The connection arrangement  270  includes a first latching connection  214  that releaseably locks that tray  236  in the non-pivoted position ( FIG. 15 ) and a separate second connection  216  that releaseably locks the tray  236  in the pivoted position ( FIG. 13 ). Each of the first and second connections  214 ,  216  is independent of the other; i.e., is a separate component that functions independent of the other component. 
   Referring to  FIGS. 13 and 14 , the first connection  214  of the connection arrangement  270  includes a first lever arm  218 . The lever arm  218  has a first end  220  and a second end  222 . The first end  220  of the lever arm  218  is non-pivotally attached to a flange  282  ( FIG. 13 ) of a side plate  242  of the drawer  226  at an attachment location  230 . 
   A lock piece  290  ( FIG. 14 ) is secured to the second end  222  of the lever arm  218 . The lever arm  218  can include a guide or locating notch  254  sized to receive locating structure  256  (e.g., a lip) of the lock piece  290 . While in the illustrated embodiment, the lock piece  290  is a separate piece from that of the lever arm  218 , it is contemplated that the lock piece can be an integral construction of the lever arm. In use, the lock piece  290  functions to releaseably lock the tray  236  in the non-pivoted position. In particular, the lock piece  290  engages a corresponding aperture or hole  292  (see  FIGS. 13 and 16 ) formed in the tray  236  of the drawer  226  to lock the tray  236  in the non-pivoted position. 
   Still referring to  FIGS. 13 and 14 , the second connection  216  of the connection arrangement  270  generally includes a second lever arm  272  and a pin assembly  276 . The second lever arm  272  has a first end  278  and a second end  280 . As shown in  FIG. 13 , the first end  278  of the lever arm  272  is pivotally attached to the flange  282  of the side plate  242  of the drawer  226  at an attachment location  258 . The lever arm  272  is also slidably attached to the tray  236  adjacent to the second end  280  of the arm. That is, the lever arm  272  defines a slide or slot  274  ( FIG. 14 ) that cooperates with the pin assembly  276  to provides a pin and slot connection between the tray  236  and the drawer frame  246 . 
   In the illustrated embodiment, each of the first and second lever arms  218 ,  272  of the connection arrangement  270  is flexibly constructed. The lever arms  218 ,  272  can be constructed of spring steel, for example, or in the alternative, can be of a molded construction. In addition, the second end  280  of the lever arm  272  is a biased end having a formed angular construction that acts as a leaf-type spring. In one embodiment, the second end  280  of the lever arm  272  is angled at an approximate 2 degree offset from the first end  278  of the arm. 
   Referring to  FIG. 14 , the pin assembly  276  of the connection arrangement  270  includes a bushing or plug body  286  having a first smaller diameter portion  244  and a second larger diameter portion  248 . The plug body  286  is mounted on a pin  284 , which is attached or affixed to the bottom tray  236 . 
   In use, the flexible construction of the first lever arm  218  permits a technician to release the tray  236  from the locked non-pivoted position by flexing the lever arm  218  in a direction C ( FIG. 16 ) outward from the tray  236 . An angled tab  294  is provided at the second end  222  of the arm to assist the technician in grasping and flexing the lever arm. The outward flexure of the lever arm  218  disengages the lock piece  290  from the aperture  292  of the bottom tray  236 . 
   When the lock piece  290  is disengaged from the aperture  292 , the tray  236  can be pivoted to the pivoted position shown in  FIG. 13 . While pivoting the tray  236 , the smaller diameter portion  244  of the plug body  286  of the second connection  216  slides within a slide portion  296  ( FIG. 14 ) of the slot  274 . Pivoting motion of the tray  236  is limited at a point where the pin assembly  276  seats within an end portion  298  of the slot  274 . 
   As previously described, the second end  280  of the second lever arm  272  is biased outward. While the tray  236  is pivoting downward, the smaller portion diameter  244  of the pin assembly  276  slides within the slide portion  296  of the slot  274 . The larger diameter portion  248  of the pin assembly prevents the biased end  280  of the lever arm from springing or moving outward from the tray  236 . 
   When the tray reaches the pivoted position, the tray  236  automatically locks into place. That is, in the pivoted position, the biased end  280  of the lever arm  272  is no longer constrained by the plug body  286 . Instead, the end portion  298  of the slot  274  now moves laterally outward to position about or engage the larger diameter  248  of the plug body. The lateral outward movement is caused by the biased construction of the flexible arm  272 . Because the slide portion  296  of the slot  274  is sized to receive only the smaller diameter portion  244  of the pin assembly  276 , the tray  236  is thereby locked in the pivoted position. 
   To release the tray from the pivoted, locked position, the lever arm  272  is simply flexed inward toward the tray  236  such that the slot  274  aligns with the smaller diameter portion  244  of the plug body  286 . The smaller diameter portion of the plug body  286  then slides upward within the slide portion  296  of the slot  274  as the tray  236  is pivoted back to the non-pivoted position. 
   Upon returning the tray  236  to the non-pivoted position, a ramped surface  250  ( FIG. 16 ) of the lock piece  290  contacts an edge  252  (see also  FIG. 13 ) of the bottom tray  236 . The ramped surface  250  acts as a guide to ease the engagement between the bottom tray  236  and the locking piece  290 , and gradually flex the lever arm  218  outward. As the tray  236  is further pivoted, the lock piece  290  seats within the aperture  292  formed in the bottom tray  236  to automatically lock the tray  236  in the non-pivoted position. 
   The above specification provides a complete description of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, certain aspects of the invention reside in the claims hereinafter appended.