Patent Publication Number: US-2023164257-A1

Title: Tray tower with position indexing trays

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation of U.S. patent application Ser. No. 17/051,710, filed on Oct. 29, 2020, which is a National Stage Patent Application of PCT/US2019/029303, filed on Apr. 26, 2019, which claims the benefit of U.S. Patent Application Ser. No. 62/665,275, filed on May 1, 2018, the disclosures of which are incorporated herein by reference in their entireties. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
    
    
     BACKGROUND 
     To increase storage density, some telecommunications equipment resides in stacked and hinged trays. In order to gain access to one of the hinged trays, the trays above that tray must be rotated up and held in this position. In some prior art designs, a separate member, sometimes referred to as a “kickstand” is provided on each tray that can be rotated to hold the tray and all above trays in the upward position. Necessarily, the kickstand must be designed to hold the weight of multiple trays. Improvements are desired. 
     SUMMARY 
     In one aspect of the disclosure, a telecommunications system is disclosed. 
     In some examples, a telecommunications tray assembly is disclosed including a tower structure and at least one hinged tray rotatably mounted to the tower structure, the hinged tray being rotatable between at least two indexed positions, wherein the hinged tray is positively retained in the at least two indexed positions by a position retention structure. 
     In some examples, the at least one hinged tray includes a plurality of hinged trays. 
     In some examples, the position retention structure includes a spring member. 
     In some examples, the tower structure includes a first recess and a second recess and wherein the spring member is positioned within the first recess when the tray is in one of the at least two indexed positions and is positioned within the second recess when the tray is in the other of the at least two indexed positions. 
     In some examples, the spring member is integrally formed with the hinged tray. 
     In some examples, the hinged tray is a unitarily formed component. 
     In some examples, the spring member is supported by a pair of deflectable support arms. 
     In some examples, the hinged tray includes a pair of hinge arms engaged with the tower structure. 
     In some examples, a telecommunications tray is disclosed including a main body an end wall and a perimeter sidewall defining an interior region for the storage of telecommunications components, a first hinge arm and a second hinge arm extending away from the main body, the first and second hinge arms each including a projection for rotatably mounting the tray to a tower structure, and a position retention structure including a spring member, the spring member being spaced from the first and second hinge arms. 
     In some examples, the position retention structure includes a first hinge arm, a second hinge arm, and a spring member extending between the first and second hinge arms. 
     In some examples, the first and second hinge arms are deflectable. 
     In some examples, the position retention structure includes at least one cantilevered spring member. 
     In some examples, the telecommunications tray is unitarily formed as a single component. 
     In some examples, the projections of the first and second hinge arms extend inwardly towards each other. 
     In some examples, a telecommunications tray assembly is disclosed that includes a tower structure and a plurality of stacked hinged trays rotatably mounted to the tower structure, wherein the hinged trays being rotatable between at least two indexed positions, wherein the hinged trays are positively retained in the at least two indexed positions by a position retention structure. 
     In some examples, the position retention structure of each of the plurality of hinged trays includes a spring member. 
     In some examples, the spring member of each tray is integrally formed with the hinged tray. 
     In some examples, each hinged tray is a unitarily formed component. 
     In some examples, all of the plurality of hinged trays can be rotated simultaneously between the at least two indexed positions. 
     In some examples, the position retention structure of each of the plurality of hinged trays holds the entire weight of the hinged tray when the hinged tray is in at least one of the two indexed positions. 
     In some examples, a telecommunications tray includes a main body defining a telecommunications component storage area, a connection structure configured for rotatably connecting the main body to a tower or base structure, and a position retention structure including a spring member, the spring member being spaced from the connector. 
     In some examples, the connection structure and the position retention structure are integrally formed with the main body. 
     A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based. 
    
    
     
       DRAWINGS 
         FIG.  1    is a perspective view of a telecommunications tray assembly in accordance with principles presented herein. 
         FIG.  2    is a top view of the telecommunications tray shown in  FIG.  1   . 
         FIG.  3    is a side view of the telecommunications tray shown in  FIG.  1   . 
         FIG.  4    is a perspective view of the telecommunications tray assembly shown in  FIG.  1   , with only a single tray installed. 
         FIG.  5    is a side cross-sectional schematic view of the telecommunications tray assembly shown in  FIG.  4   , with the tray shown in multiple possible positions. 
         FIG.  6    is a partial top view of the tray shown in  FIG.  5   , when the tray is in a second or intermediate position. 
         FIG.  7    is a partial top view of the tray shown in  FIG.  5   , when the tray is in a lowered or third or raised position. 
         FIG.  8    is a perspective view of one of the trays shown in  FIGS.  1  and  5   . 
         FIG.  9    is a top view of the tray shown in  FIG.  8   . 
         FIG.  10    is a bottom view of the tray shown in  FIG.  8   . 
         FIG.  11    is an end view of the tray shown in  FIG.  8   . 
         FIG.  12    is a longitudinal cross-sectional view of the tray shown in  FIG.  8   . 
         FIG.  13    is a perspective view of a tower structure of the tray assembly shown in  FIG.  1   . 
         FIG.  14    is a first side view of the tower structure shown in  FIG.  13   . 
         FIG.  15    is a second side view of the tower structure shown in  FIG.  13   . 
         FIG.  16    is a top view of the tower structure shown in  FIG.  13   . 
         FIG.  17    is a front view of the tower structure shown in  FIG.  13   . 
         FIG.  18    is a schematic side view of the tower structure shown in  FIG.  13   . 
         FIG.  19    is a perspective view of the telecommunications tray assembly shown in  FIG.  1   , with the trays installed in an orientation 180 degrees to that shown in  FIG.  1   . 
         FIG.  20   , is a perspective view of the tray assembly shown in Figure showing a first tray removal step. 
         FIG.  21   , is a perspective view of the tray assembly shown in Figure showing a second tray removal step. 
         FIG.  22   , is a perspective view of the tray assembly shown in Figure showing a third tray removal step. 
         FIG.  23    is a bottom view of the tray assembly shown in  FIG.  1   , utilizing an alternative tray design. 
         FIG.  24    is a top perspective view of the tray assembly shown in  FIG.  23   . 
         FIG.  25    is a bottom perspective view of the tray assembly shown in  FIG.  23   . 
         FIG.  26    is a perspective view of a second example of a telecommunications tray assembly in accordance with principles presented herein. 
         FIG.  27    is a perspective view of the telecommunications tray assembly shown in  FIG.  26   , with only a single tray installed. 
         FIG.  28    is a perspective view of a tray of the tray assembly shown in  FIG.  26   . 
         FIG.  29    is a top view of the tray shown in  FIG.  28   . 
         FIG.  30    is a bottom view of the tray shown in  FIG.  28   . 
         FIG.  31    is an end view of the tray shown in  FIG.  28   . 
         FIG.  32    is a longitudinal cross-sectional view of the tray shown in  FIG.  28   . 
         FIG.  33    is a partial perspective view of the tray shown in  FIG.  28   . 
         FIG.  34    is a perspective view of a tower structure of the tray assembly shown in  FIG.  26   . 
         FIG.  35    is a first side view of the tower structure shown in  FIG.  34   . 
         FIG.  36    is a second side view of the tower structure shown in  FIG.  34   . 
         FIG.  37    is a top view of the tower structure shown in  FIG.  34   . 
         FIG.  38    is a front view of the tower structure shown in  FIG.  34   . 
         FIG.  39    is a side view of the telecommunications tray assembly shown in  FIG.  26   , with a single tray shown in multiple possible positions moving from a first or lowered position to a third or raised position. 
         FIG.  40    is a side view of the telecommunications tray assembly shown in  FIG.  39   , with the tray shown in multiple possible positions moving from a third or raised position to a first or lowered position. 
         FIG.  41    is a side view of the telecommunication tray assembly shown in  FIG.  26    with the uppermost tray being shown in a third or raised position and the bottom three trays being shown in a first or lowered position. 
         FIG.  42    is a side view of the telecommunication tray assembly shown in  FIG.  26    with the upper three trays being shown in a third or raised position and the bottom tray being shown in a first or lowered position. 
         FIG.  43    is a partial perspective view of a third example of a telecommunications tray assembly in accordance with principles presented herein. 
         FIG.  44    is a side view of the telecommunications tray assembly shown in  FIG.  43    with the two uppermost trays being shown in a third or raised position and the bottommost three trays being shown in a first or lowered position. 
         FIG.  45    is a side view of the telecommunications tray assembly shown in  FIG.  43    with the two uppermost trays being shown in a third or raised position, the middle tray being shown in a second or intermediate position, and the bottommost two trays being shown in a first or lowered position. 
         FIG.  46    is a partial perspective view of one of the trays shown in  FIG.  43   . 
         FIG.  47    is a top partial view of the tray shown in  FIG.  46   . 
         FIG.  48    is a partial cross-sectional view of the tray shown in  FIG.  46   . 
         FIG.  49    is a front view of an enclosure within which the tray assemblies of the disclosure can be installed. 
         FIG.  50    is a cross-sectional side view of the enclosure shown in  FIG.  46    housing a tray assembly in accordance with the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to exemplary aspects 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. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
     Enclosures 
       FIGS.  49  and  50    show an enclosure  20  for housing the disclosed tray assemblies  100 ,  200 ,  300 . In one aspect, the enclosure  20  defines a central longitudinal axis  22  that extends along a length of the enclosure  20  from a bottom end  24  to a top end  26 . A base  28  defines the bottom end  24  of the enclosure  20  while a dome  30  defines the top end  26  of the enclosure  20 . The base  28  and the dome  30  are interconnected by a clamp  32  that mounts over flanges respectively defined by the base  28  and the dome  30 . A seal can mount between the flanges to provide an environmental seal that prevents moisture, dust and, pests from entering the interior of the enclosure  20 . Although a pedestal type enclosure  20  is shown, enclosure  20  may also be configured for aerial, buried, or underground applications. A plurality of primary cable through-ports extend through the base  28  for allowing cables  40  (e.g., trunk cables, drop cables, or other cables) to enter the enclosure  20 . To accommodate drop cables or other smaller cables (i.e., secondary cables), secondary cable tube assemblies  38  are mounted in some of the primary cable through-ports. The remainder of the primary cable through-ports  36  can receive plugs used to seal the unoccupied primary cable through-ports. Referring to  FIG.  50   , the interior of the enclosure  20  can be seen. 
     Within the enclosure, a tray assembly  100  is housed. As is discussed in the next section, the tray assembly  100  includes a plurality of hinged trays  110  supported by a tower structure  120 , which is in turn supported by a base structure. The hinged trays  110  are individually rotatable with respect to the base structure  120  and enclosure  20  to allow for access to any splice without disturbing fibers in other hinged trays  110 . In one aspect, the trays house and support fiber-optic cables and ensure that fiber-optic cables can be spliced and housed, quickly and easily. Additionally, the hinged trays  110  support fast, mass splicing jobs in feeder and long-haul areas of the network. The hinged splice hinged trays  110  are compatible with many common cable types. 
     Tray Assemblies 
     It is noted that the following description utilizes directional language (e.g. raised, lowered, upper, lower, horizontal, vertical, etc.) that indicates a particular orientation. Although the disclosed tray assemblies  100  can be oriented as shown in the drawings, many other orientations are possible, and the directional language used herein should not be taken to limit the disclosure. 
     Referring to  FIGS.  1 - 25   , a first example of a tray assembly  100  is presented. As shown, the tray assembly  100  includes a plurality of trays  110  rotatably connected to and supported by a tower structure  120 . In some examples, each of the trays  110  is unitarily formed as a single component. Due to the design of the features of the tray  110 , and in particular the design of the position retention structure  116  (described below), the tray  110  can be molded as a unitarily formed component without requiring any undercuts. In some examples, the tower structure  120  is unitarily formed as a single component. In some examples, the trays  110  and/or tower structure  120  are formed from a polymeric material, such as an ABS polycarbonate material. 
     As shown, each of the trays  110  defines a tray portion  112  and a hinge portion  114  connected to the tray portion  112 . The tray portion  112  is shown as defining an end wall  112   a  from which a perimeter sidewall  112   b  extends. Together, the end wall  112   a  and sidewall  112   b  define an interior storage space  112   c  for housing telecommunications cables and other related components. Although the end wall  112   b  is shown without any further features, additional projections and structures can be provided to facilitate the retention of telecommunications cables and other related components. 
     The hinge portion  114  is shown as including a pair of oppositely positioned, spaced apart hinge arms  114   a ,  114   b  supported by a sidewall  114   c  to form a generally u-shaped structure. In one aspect, the sidewall  114   c  extends from the end wall  112   a  of the tray portion  112 . Each of the hinge arms  114   a ,  114   b  is shown as being provided with an inwardly extending projection  114   d  which is received by corresponding apertures  124  in the tower structure  120 . As is explained in more detail later, the hinge arms  114   a ,  114   b  are provided with sufficient flexibility to allow for the hinge arms  114   a ,  114   b  to be deflected away from the tower structure  120  such that the inwardly extending projections  114   d  can be aligned with the apertures  124  during installation and removal of the tray  110  from the tower  120 . 
     Each tray  110  is also shown as being provided with a position retention structure  116  including a pair of support arms  116   a ,  116   b  that support a leaf spring member  116   c . In one aspect, the support arms  116   a ,  116   b  extend from the sidewall  114   c  in a direction towards the projections  114   d . In one aspect, the support arms  116   a ,  116   b  extend in a direction that is parallel to the length of the hinge arms  114   a ,  114   b  and are spaced away from the hinge arms  114   a ,  114   b  in an inward direction such that the support arms  116   a ,  116   b  reside between the hinge arms  114   a ,  114   b . The support arms  116   a ,  116   b  are provided with some elasticity such that forces exerted onto the leaf spring member  116   c  result in deflection of the support arms  116   a ,  116   b . As the support arms  116   a ,  116   b  are spaced away from the hinge arms  114   a ,  114   b , the forces transmitted to the support arms  116   a ,  116   b  from the leaf spring member  116   c  are not transmitted to the hinge arms  114   a ,  114   b . As is discussed later, the leaf spring member  116   c  functions as a positioning member that enables the tray  110  to be positively retained or indexed into either a raised or first or lowered position. By the use of the term positively retained or positively indexed, it is meant to describe a position in which an external force must be applied to rotate the tray  110  out of the indexed or retained position. 
     As presented, the tower structure  120  is formed as a main body  122  defining a plurality of apertures  124  for receiving the projections  114   d  of each tray  110 . In the example shown, four apertures  124  for holding four trays  110  are shown. However, more or fewer apertures  124  can be provided. In one aspect, the apertures  124  are defined by a sidewall  124   a  having a chamfered or scalloped portion  124   b  and a ramped portion  124   c  to allow for easier insertion of the projections  114   d  into the apertures  124 . The tower structure is also provided with a plurality of recesses  126  separated by slightly rounded bridge members  128 . In one aspect, the apertures  124 , recesses  126 , and bridge members  128  are aligned at an angle α 1 . The angle α 1  results in these features being offset from each other at a distance P 2  such that the adjacently above corresponding features are recessed horizontally (as shown on the page at  FIG.  18   ) with respect to the lower features by this same offset. This construction allows the hinged trays  110  to be slightly offset from each other in the lengthwise direction (i.e. upper tray  110  is offset towards the tower structure  120  relative to the lower tray  110 , as most easily seen at  FIG.  1   ). In the example shown, angle α 1  is about 45 degrees. This offset provides for sufficient clearance such that each tray  110  can be fully rotated into the third or raised position regardless of the position of the tray. The apertures  124  are vertically spaced at a distance P 1 , the recesses  126  have a radius R 1 , and the bridge portions  128  have a radius R 2 . Although the recesses  126  and bridge portions  128  are shown as being generally circular in shape, these features can be provided with other non-symmetrical arcuate shapes such that the force required to rotate the tray  110  from one indexed position to another is greater or lesser than the force required to rotate the tray  110  in the opposite direction. 
     Referring to  FIGS.  5 - 7   , the operation of the position retention structure  116  with respect to the tower structure is most easily seen.  FIG.  5    shows a single tray  110  in multiple positions, with the tray being shown in a first or lowered position  110 - p   1 , in a third or raised position  110 - p   3 , and a second or intermediate position  110 - p   2  between the raised and first or lowered positions. In the first or lowered position  110 - p   1 , the leaf spring member  116   c  is received into the recess  126   a  that is horizontally aligned (as shown on the page) with the aperture  124  into which the projections  114  of the tray  110  are received. In this position, the leaf spring member  116   c  is in a generally relaxed position, as illustrated at  FIG.  7   , wherein the support arms  116   a ,  116   b  are in a non-deflected state (i.e. parallel to the hinge arms  114   a ,  114   b ). As the tray  110  is installed in the bottommost position, the bottom of the tray  110  is supported by a support surface  122   a  of the tower structure main body  122 . Trays  110  mounted above this position are supported by the tray  110  below. 
     When the tray  110  is rotated into the third or raised position  110 - p   3 , the leaf spring member  116   c  is snapped out of the recess  126   a  associated with the first or lowered position and into the adjacent recess  126   b . By placing any of the trays  110  into the third or raised position  110 - p   3 , the interior region  112   c  of the immediately below tray  110  remaining in the first or lowered position  110 - p   1  can be more readily accessed. The interaction between the leaf spring member  116   c  and the recesses  126  is such that a significant rotational force must be applied in order to remove the leaf spring member  116   c  from the recess  126 . Thus, once the tray  110  has been rotated into the third or raised positions  110 - p   3 , the tray  110  is easily held in position by the leaf spring member  116   c .  FIG.  7    also shows the position of the leaf spring member  116   c  when the tray  110  has been rotated into the third or raised position  110 - p   3 . 
     In order to rotate the tray from the first or lowered position  110 - p   1  to the third or raised position  110 - p   3 , or vice-versa, the tray  110  must be rotated through a second or intermediate position  110 - p   2  in which the leaf spring member  116   c  must snap out of one recesses  126   a ,  126   b  and ride along the bridge member  128  before snapping back into the other recess  126   a ,  126   b . When sufficient rotational force is applied to the tray  110  to move the tray  110  into the second or intermediate position  110 - p   2 , the contact between the leaf spring member  116   c  and the bridge member  128  forces the leaf spring member  116   c  to deflect in a direction away from the bridge member  128  (i.e. the leaf spring member  116   c  deflects towards the tray portion  112  and away from the hinge projections  114   c ). This action in turn forces an outward deflection of the support arms  116   a ,  116   b , as can be seen at  FIG.  6     4 . As the support arms  116   a ,  116   b  are spaced away from an inwardly of the hinge arms  114   a ,  114   b , the support arms  116   a ,  116   b  do not contact the hinge arms  114   a ,  114   b . This configuration thus advantageously reduces or eliminates forces exerted on the leaf spring member  116   c  from being further transmitted to the hinge arms  114  that might otherwise compromise the hinging action between the projections  114   d  and the recesses  124  and/or cause excessive fatiguing of the hinge arms  114   a ,  114   b . It is noted that the bridge member  128  is curved such that the leaf spring member  116   c  can more easily ride along the bridge member  128 . 
     It is noted that the spacing and configuration of the recesses  126  allows for multiple trays  110  to be rotated together simultaneously between the first or lowered positions  110 - p   1  to the third or raised positions  110 - p   3 . The trays  110  can also be rotated one at a time. With either approach, the interior region  112   c  of any tray  110  can be readily accessed by rotating the above trays  110  into the third or raised position  110 - p   3 . As each tray  100  in the third or raised position  110 - p   3  is independently supported, it is not necessary for any below tray  110  to support the weight of the trays above the tray  110 , as is the case with prior art designs using a support member on each tray that supports that tray and all trays above. Additionally, as the trays  110  are each independently retained in the first or lowered position  110 - p   1 , it is not necessary to provide a Velcro strap to restrain the trays in this position, as is the case with some prior art designs. Although each tray  110  is shown as being positionable between two indexed positions defined by the recesses  126 , additional recesses  126  could be provided such that the tray  100  can be rotated into more than two indexed positions. 
     The disclosed design is also advantageous in that both tactile and audible feedback are provided by the snapping action of the leaf spring member  116   c  into and out of the recesses  126 . Thus, an operator can readily ascertain when the tray  110  has been sufficiently rotated into or out of the first or lowered position  110 - p   1  and into or out of the third or raised position  110 - p   3 . In this way, the recesses  126  and leaf spring member  116   c  perform a position indexing function. Accordingly, the positions  110 - p   1  and  110 - p   3  can be characterized as indexed positions. As the trays  110  are automatically retained into the third or raised position  110 - p   3 , the operator does not need to perform any further actions to secure the trays  110  into this position. As the trays  110  are positively retained in the position entirely by the interaction between the leaf spring member  116   c  and the recesses  126 , the trays  110  can also be characterized as being auto-latching. Although the disclosed tray assembly  100  is shown with a spring member  116   c  located on the tray and recesses  124  located on the tower structure  120 , it is possible to reverse these features such that the tower structure  120  is provided with multiple spring members and the tray forms a corresponding recess for receiving the spring members. 
     Referring to  FIG.  19   , it can be seen that the trays  110  can be installed in an opposite orientation on the same tower structure  120  such that the interior regions  112   c  are facing in a downward direction (on the page) in comparison to the arrangement shown at  FIG.  1   . 
     Referring to  FIGS.  20 - 21   , it can be seen that a tool  10 , such as a flathead screwdriver, can be used to remove a tray  110  from the tower structure  120 .  FIG.  20    shows the tool  10  inserted between the tower structure  120  and a hinge arm  114   a . Once the tool  10  is placed in this position, the tool  10  is rotated to force the projection  114   d  out of the recess  124 , as shown in  FIG.  21   . Once this position is reached, the tray  110  can be rotated such that the hinge arm  114   a  is clear of the tower structure  120  such that the projection  114   d  on the other side can be also be removed from the recess  124 . The tray  110  can then be fully removed, as shown at  FIG.  22   . 
     Referring to  FIGS.  23 - 25   , a tray variation is shown in which the use of the tool  10  is not necessary in order to facilitate removal of the trays  110 . As shown, the hinge arms  114   a ,  114   b  of the trays are each provided with a handle or tab portion  114   e . The handle or tab portions  114   e  extend from an end of the hinge arms  114   a ,  114   b  in a laterally outward direction from the associated hinge arms  114   a ,  114   b  and then curve back at an oblique angle to the hinge arms  114   a ,  114   b  to provide a tactile surface for an operator&#39;s finger. The handle or tab portions  114   e  can thus be used by the user to manually deflect the hinge arms  114   a ,  114   b  away from the tower structure  120  to release the projections  114   d  from the recesses  124 . 
     Referring to  FIGS.  26 - 42   , a second example of a tray assembly  200  is presented. As many features of the tray assembly  200  are similar to those of tray assembly  100 , the description for tray assembly  100  is largely applicable for tray assembly  200 . For example, the profile of apertures, recesses, and apertures of the tower structure  120  is generally the same for tower structure  220 . Thus, the description of tray assembly  200  will be limited to the differences over tray assembly  100 . 
     The primary distinguishing feature of the tray assembly  200  is that a different position retention structure  216  is utilized in which a pair of independent spring members  216   c  projecting from the sidewall  214   c  are utilized. As with support arms  116   a ,  116   b , spring members  216   c  are inwardly spaced from the hinge arms  214   a ,  214   b  and run generally parallel to the hinge arms  214   a ,  214   b . The tower structure  220  is also shown as having a corresponding pair of members  222   b ,  222   c  with each having apertures  224 , recesses  226 , and bridge members  228  for interacting with the spring members  216   c . Thus, tray assembly  200  has the same advantage of tray assembly  100  in that forces exerted onto the spring members  216   c  are not transmitted to the hinge arms  214   a ,  214   b  which could otherwise compromise the operation or service life of the hinge structure. 
     As most easily seen at  FIG.  33   , each spring member  116   c  is structured as a deflectable cantilevered beam with a main portion  216   d  extending from the sidewall  214   c  along a first length L 1 . As shown, the main portion  216   d  has a first width W 1  and tapers from a height H 1  to a second height H 2 , wherein height H 2  is less than height H 1 . The spring member  216   c  is also provided with a head portion  216   e  at the distal end of the main portion  216   d . The head portion  216   e  defines an outer surface  216   f  having a radius R 3 . During rotation of the tray  210 , the head portion outer surface  216   f  engages with the recesses  226  and bridge portions  228  of the tower structure  220  to result in a similar indexing or auto-latching function described for tray assembly  100 . It is noted that the tray assembly  100  can be provided with a shorter overall length as compared to tray assembly  200  as the spring member  116   c  is oriented in a transverse direction to the tray  110  and tower structure  120  rather than being oriented in a lengthwise direction (i.e. direction of length L 1 ) as is the case with tray assembly  200 . 
     With reference to  FIGS.  39  and  40   , the interaction between the spring members  116   c  and the tower structure recesses  126  and bridge members  128  of the tower structure  120  is shown.  FIG.  39    shows the tray  210  being rotated in a direction D 1  from the first or lowered position  210 - p   1  to the third or raised position  210 - p   3  with multiple intermediate or second positions  210 - p   2  also being shown. As the tray  210  is being rotated in the direction D 1 , the main portions  216   d  deflect downwardly thereby allowing the head portion outer surface  216   f  to ride out of the recess  226   a  across the bridge portion  226  and then to snap into the recess  226   b . Once in this position, the spring member main portion  216   d  can return to a relaxed or non-deflected state to positively retain the tray in the third or raised position  210 - 3 .  FIG.  40    shows the tray  210  being moved back from the third or raised position  210 - 3  to the first or lowered position  210 - 1 , wherein the spring member main portion  216   d  deflects in an upward direction to allow the head portion  216   d  to eventually snap out of the recess  226   b  and into the recess  226   a . As with the tray  110 , the rotation between these positions provides both audible and tactile feedback to an operator, wherein the spring member  216  of each tray  210  has sufficient strength to independently hold the tray  210  in the third or raised position  210 - p   3 .  FIG.  41    shows one configuration in which the uppermost tray  210  is independently retained in the third or raised position  210 - p   3  by the spring members  216   c  such that the interior region  212   c  of the tray below can be accessed.  FIG.  42    shows another configuration in which the three uppermost trays  210  are held in the third or raised position  210 - p   3  by the spring members  216   c  such that the interior region  212   c  of the bottommost tray  210  can be accessed. 
     Referring to  FIGS.  43  to  48   , a third example of a tray assembly  300  is presented. Tray assembly  300  is similar to tray assemblies  100  and  200  in that the trays  310  can be independently held and indexed into the first and third positions  310 - p   1 ,  310 - p   3  without the use of an additional support component. However, unlike tray assemblies  100  and  200 , tray assembly  300  does not rely upon a spring member to index the trays into position. Rather, each tray  310  is provided with a pair of support arms  114   a  with each having a pin  314   d  and extension members  316  that are operated within slot structures of the tower structure  320  that enable each tray to be slid in and out from different locked positions  310 - p   1 ,  310 - p   3 . As presented, the tower structure  320  is provided with a main body  322  having a pair of support members  322   a ,  322   b  with each defining a first array of slot structures  324  and a second array of slot structures  326 . The pins  314   d  of each tray  310  are received and retained within one of the slot structures  324  while the extension members  316  of each tray  310  are received into a corresponding one of the slot structures  326 . The slot structure  324  has a closed L-shape with a first portion  324   a  and a second portion  324   b . In the orientation shown, the first portion  324   a  is horizontal and the second portion  324   b  is vertical. The slot structure  326  has an open L-shape with a first portion  326   a  and a second portion  326   b . In the orientation shown, the first portion  326   a  is horizontal and the second portion  326   b  is vertical. As the slot structure  324  is closed, the pins  314   d  are always retained within a slot structure  324  unless the tray  310  is removed from the tower structure  320 . The open, second slot structure  326  removably receives the extension members  316  of the tray  310 . 
     When the tray  310  is in the first or lowered position  310 - p   1 , the extension members  316  are received in the first portion  326   a  of the second slot structures  326  while the pins  314   d  are received in the first portion  324   a  of the first slot structure  324 . In this position, the tray  310  is positively retained in the position  310 - p   1  without the need for any additional components. To move the tray  310  to the third or raised position  310 - p   3 , the tray  310  is pulled in a direction D 2  such that the extension members  316  are removed from the second slot structures  326  and the pins  314   d  are drawn over the first slot structure second portions  324   b . In this position, the tray  310  can be rotated in the direction D 1  through intermediate positions  310 - p   2  (see  FIG.  45   ) until the tray is oriented to align with the next or adjacent second slot structure  326 , which in this case is a vertical orientation of the tray  310 . Once in this position, the tray  310  is moved in a direction D 3  such that the extension members  316  are received by the second portion  326   b  of the second slot structure and the pins are pushed fully into the first slot structure second portions  324   b . At this point, the tray  310  is now secured into the third or raised position  310 - p   3 . Moving a tray  310  from the position  310 - p   3  to the position  310 - p   1  is simply the reverse of the above described procedure.  FIG.  44    shows two trays  310  in the position  310 - p   3  and three trays in the position  310 - p   1  while  FIG.  45    shows two trays  310  in the position  310 - p   3 , three trays in the position  310 - p   1 , and one tray  310  being moved through the intermediate positions  310 - p   2 . 
     Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.