Carrier for multiple splice trays

<b>Field of the Invention</b>

0001The present invention is directed to the splicing of optical fibers, and more particularly to the splicing of optical fibers with splicing trays.

<b>Background of the Invention</b>

0002Optical fibers and cables have become very common data carriers. One issue that can arise with optical fibers is their interconnection with other optical fibers. For example, many industrial, office and apartment buildings include data centers, where cables transmitting data from outside the building are ultimately interconnected with devices (phones, computers, and the like) inside the building. Commonly, incoming optical fibers pass to the data center in cable form, where they are spliced together with "pigtail" cables. The pigtail cables travel to a termination point, where they are interconnected with a termination device (for example, a termination cartridge or module) that, in turn, interconnects them with "jumper" fibers that exit to other parts of the building for use with various devices.

0003Splicing of optical fibers is often accomplished via one of three different splicing techniques: mechanical splicing; fusion splicing; or mass fusion splicing. These techniques are well known and need not be described in detail herein. Splices are often stored in splice trays, which are generally planar devices that include multiple splicing sites designed to organize interconnected fibers and splices. Splice trays can assist in keeping a number of spliced fibers in an organized arrangement (typically a tray will have a capacity of 6 to 24 splices). Splice trays are then stored inside shelves on an equipment rack within the data center. An exemplary splice tray is the 2524-MF FIBRLOK multi-fiber splice organizer tray, available from 3M, Minneapolis, Minnesota.

0004As data centers are required to handle increased amounts of data, they often accumulate vast numbers of cables, pigtail fibers and jumper fibers to be spliced and terminated. In an effort to include increasing numbers of splice trays on a single shelf, in some instances splice trays have been stacked on top of one another to reduce the amount of space that they occupy; in certain of these instances, the splice trays have been adhered together with "double-stick" tape to attempt to maintain some degree of organization within an equipment rack shelf. Nevertheless, as the density of cables and fibers grows, it would be desirable to provide more splicing sites in a limited space, and to maintain and/or improve the level of organization that that splice trays can provide.

<b>Summary of the Invention</b>

0005The present invention is directed to a multi-tray splice site carrier that can accommodate and organize multiple splice trays in a relatively small space and present them quickly and easily for work thereon. As a first aspect, a splice site carrier of the present invention includes an interconnecting member and a plurality of generally planar carrier members that are pivotally interconnected with the interconnecting member. The carrier members are configured to receive a splice tray mounted on a front side thereof. Each of the carrier members is pivotable about a respective pivot axis between an access position, in which the front side of the carrier member faces in a first direction, such that the splice tray is presented for access to splice sites thereon, and a non-access position that is at least partially inverted from the access position, in which a rear side of the carrier member is presented and the splice tray is not accessible. When all of the plurality of carrier members are in the access position, at least some of the carrier members are in stacked, generally parallel relationship, and when all of the carrier members are in the non-access position, at least some of the carrier members are in stacked, generally parallel relationship. The carrier members can be rotated individually from the access position to the non-access position to provide access to any of the carrier members. In this configuration, a user can quickly access any of the splice trays in index-card fashion while the splice trays remain in an organized arrangement.

0006In some embodiments, the interconnecting member is a base, with the carrier members being pivotally interconnected with the base. In certain of these embodiments, the respective pivot axes of the carrier members may be staggered vertically and horizontally relative to one another. The non-access position may cause the front side of the carrier member to be generally inverted from the access position, or may cause the front side of the carrier member to face in a direction generally normal to that of the access position.

0007In other embodiments, the splice site carrier can be formed of an elongate sheet of flexible material that is folded upon itself to form a plurality of leaves that serve as carrier members, with intermediate panels positioned between pairs of leaves serving as the interconnecting member. In this embodiment, the carrier members pivot relative to the intermediate panels via living hinges formed in the elongate sheet. In certain embodiments, when the carrier members are in their access positions, they are in stacked, generally parallel relationship with each other. A cover member that is also formed from the flexible sheet can be employed to secure the carrier members in their access positions.

<b>Brief Description of the Figures</b>

0008<ul id="ul0001" list-style="none" compact="compact"><li><b>Figure 1</b> is a perspective view of a splice site carrier according to embodiments of the present invention, wherein the carrier members are shown in their access positions.</li><li><b>Figure 2</b> is a side view of the splice site carrier of <b>Figure 1</b> with the carrier members in their access positions</li><li><b>Figure 2A</b> is a side view of the splice site carrier of <b>Figure 1</b> as shown in <b>Figure 2</b>, with the frontmost carrier member in its non-access position.</li><li><b>Figure 3</b> is a top perspective view of a splice site carrier according to other embodiments of the present invention, wherein the carrier members are shown in their access positions.</li><li><b>Figure 4</b> is a top perspective view of the splice site carrier of <b>Figure 3</b> with one carrier member shown in its non-access position and two carrier members shown in an intermediate position.</li><li><b>Figure 5</b> is a partially exploded top perspective view of the splice site carrier of <b>Figure 3</b> with three splice trays removed and one splice tray shown in phantom line.</li><li><b>Figure 6</b> is a bottom perspective view of the splice site carrier of <b>Figure 3</b> with the carrier members in their access positions.</li><li><b>Figure 7</b> is a bottom perspective view of an alternative embodiment of a splice site carrier like that in <b>Figures 3-6</b> configured for floor mounting.</li><li><b>Figure 8</b> is a perspective view of a splice site carrier according to additional embodiments of the present invention, wherein the carrier panels are secured in their access positions by the cover member.</li><li><b>Figure 9</b> is a side perspective view of the splice site carrier of <b>Figure 8</b> with the cover member detached and the carrier panels and splice trays mounted thereto in a variety of intermediate positions.</li><li><b>Figure 10A</b> is a top view of a blank of an elongate flexible sheet used to form the splice site carrier of <b>Figure 8</b>.</li><li><b>Figure 10B</b> is a bottom view of a blank of an elongate flexible sheet used to form the splice site carrier of <b>Figure 8</b>.</li><li><b>Figure 11</b> is a side perspective view of the splice site carrier of <b>Figure 9</b> with the splice trays removed.</li><li><b>Figure 12</b> is a perspective view of a splice site carrier of <b>Figures 9-11</b> in place in a data center shelf.</li></ul>

<b>Detailed Description of Embodiments of the Invention</b>

0009The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments or other embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the figures, the dimensions of some components may be exaggerated for clarity.

0010Turning now to the figures, a splice site carrier of the present invention, designated broadly at <b>20</b>, is illustrated in <b>Figures 1, 2</b> and <b>2A</b>. The carrier <b>20</b> includes a base <b>22</b> configured to rest on or be mounted upon an underlying surface, such as the upper surface of a shelf within a data center equipment rack. The base <b>22</b> has a floor <b>23</b> and short side rails <b>24</b> on opposite sides of the floor <b>23</b>. Four slotted apertures <b>26</b> with open upper ends are located on each side rail <b>24</b>. The apertures <b>26</b> are positioned such that each aperture <b>26</b> is in substantial alignment with an aperture 26 on the opposite side rail 24, with the result that each opposing pair of apertures <b>26</b> forms a respective pivot axis <b>A1, A2, A3, A4.</b> In the illustrated embodiment, all of the pivot axes <b>A1-A4</b> are positioned at essentially the same distance from the surface underlying the base <b>22</b>.

0011Referring again to <b>Figures 1, 2</b> and <b>2A,</b> the carrier <b>20</b> also includes four carrier members <b>30</b>. Because the carrier members <b>30</b> are substantially identical, only one carrier member <b>30</b> will be described herein; those skilled in this art will appreciate that the discussion is equally applicable to the remaining carrier members <b>30</b>.

0012Referring still to <b>Figures 1</b> and <b>2</b>, the carrier member <b>30</b> has a generally planar main plate <b>32</b>. At its lower end, the main plate <b>32</b> has two laterally-extending pins <b>34</b> that are received in an opposing pair of the apertures <b>26</b> of the base <b>22</b>. The pins <b>34</b> are free to rotate within the apertures <b>26</b> about a respective pivot axis <b>A1-A4.</b>

0013Each carrier member <b>30</b> supports a splice tray <b>36</b>. The splice tray <b>36</b> can be any splice tray or other device known to those skilled in this art to be suitable for providing splice sites for optical fibers. The splicing technique supported by the splice tray <b>36</b> can be mechanical, fusion, mass fusion, or any other known technique. Exemplary splice trays include the 1AF1-16LG Fusion Splice Organizer, the 1AMF1-6LG Mass Fusion Splice Organizer, and the 1AM1-12LG Mechanical Splice Organizer, all available from SYSTIMAX® Solutions, Inc. (Richardson, Texas). Other devices that supply splice sites include OFSH-T-6-01 BLK and OFSH-T-12-01 BLK, both available from Richco, Morton Grove, Illinois. In the illustrated embodiment, the splice tray <b>36</b> is mounted to the main plate <b>32</b> via an adhesive sheet <b>38</b> (shown in <b>Figure 1</b> in phantom line) with adhesive on both sides (such as "double-stick" tape), although other mounting techniques may also be employed.

0014Each of the carrier members <b>30</b> is free to rotate about its respective pivot axis <b>A1-A4</b> between an access position (as shown in <b>Figures 1</b> and <b>2</b>) and a generally inverted non-access position (<b>Figure 2A</b>). In the access position, all but the rearmost carrier member <b>30</b> are in stacked, generally parallel relationship, with the front side <b>32a</b> of the carrier member <b>30</b> facing generally upwardly, such that the splice tray <b>36</b> mounted on the frontmost carrier member <b>30</b> is presented for installation or modification of splices. Any or all of the carrier members <b>30</b> can be moved individually or as a group of any size (much like a typical index card file) to the non-access position shown in <b>Figure 2A,</b> in which rear side <b>32b</b> of the carrier member <b>30</b> faces generally upwardly, and the splice tray <b>36</b> mounted thereon is not presented for work on its splice sites. In typical operation, at least one carrier member <b>30</b> remains in the access position to that its splice sites are available for installation or maintenance work.

0015In this configuration, any number of splice trays <b>36</b> can be stored in a small space. Also, any of the splice trays <b>36</b> can be accessed quickly without disturbing the splices in any of the other splice trays <b>36</b>.

0016Those skilled in this art will recognize that the base <b>22</b> and carrier members <b>30</b> may take other configurations. For example, the base <b>22</b> may include pivot pins and the carrier members <b>30</b> may include corresponding apertures. As another example, rivets, threaded fasteners, or other components that enable one member to rotate relative to another member may replace the pins and apertures altogether. More or fewer carrier members may be employed. Other variations may be apparent to those skilled in this art and need not be described in detail herein.

0017Both the base <b>22</b> and the carrier members <b>30</b> can be formed of any suitable material, although polymeric materials are particularly suitable for their light weight and ease of molding into intricate configurations. Exemplary polymeric materials include polycarbonate, ABS, polystyrene, and other thermoplastic materials.

0018Another multi-tray splice site carrier, designated broadly at 40, is illustrated in <b>Figures 3-6.</b> The carrier <b>40</b> includes a base <b>42</b> and four carrier members <b>50;</b> these components are described in greater detail below.

0019The base <b>42</b> has two side walls <b>43</b> spanned by a vertical mounting panel <b>46</b> that includes mounting apertures <b>47.</b> The side walls <b>43</b> have a stair-step profile, with multiple horizontal edges <b>43b</b> and vertical edges <b>43a</b> (see <b>Figure 5</b>) and are divided into substantially rectangular frangible sections by grooves <b>48</b>. Each frangible section includes a pivot aperture <b>44</b>; as with the carrier <b>20</b> illustrated in <b>Figures 1-2A</b>, pivot apertures <b>44</b> on one side wall <b>43</b> are substantially aligned with pivot apertures <b>44</b> on the opposing side wall <b>43</b> to form pivot axes <b>B1, B2, B3, B4.</b> As can be seen in <b>Figure 5,</b> the pivot apertures <b>44</b> on the same side wall <b>43</b> are offset or staggered from one another, both vertically and horizontally, which in turn causes the pivot axes <b>B1, B2, B3, B4</b> to be similarly staggered. Also, portions of the edges of the side walls <b>43</b> between the horizontal edges <b>43b</b> and the vertical edges <b>43a</b> include detents <b>45</b> that are positioned forwardly and upwardly from each pivot aperture <b>44</b>.

0020Referring again to <b>Figures 3-6,</b> the four carrier members <b>50</b> are substantially identical. As a result, only one carrier member <b>50</b> will be described herein; those skilled in this art will appreciate that the discussion is equally applicable to the remaining carrier members <b>50</b>.

0021Each carrier member <b>50</b> includes a generally planar main panel <b>52.</b> A handling tab <b>54</b> extends upwardly from one end of the main panel <b>52.</b> At the other end of the main panel <b>52,</b> two pivot pins <b>58</b> extend laterally and are inserted into an aligned pair of pivot apertures <b>44</b> for pivotal movement about a respective pivot axis <b>B1-B4.</b> Also, two retention pins <b>60</b> extend laterally from the edges of the main panel <b>52</b> adjacent the pivot pins <b>58.</b> The retention pins <b>60</b> are sized and positioned to be received in the detents <b>45</b> in the side walls <b>43</b> or to rest against the horizontal or vertical edges <b>43b, 43a</b> of the side walls <b>43,</b> depending on the orientation of the carrier member <b>50</b>.

0022A latch <b>56</b> rises from the main panel <b>52</b> to capture one edge of a splice tray <b>62</b>. A nub <b>55</b> extends slightly from the handling tab <b>54</b> toward the latch <b>56</b> to capture the opposite edge of the splice tray <b>62</b>. As such, the splice tray <b>62</b> can be easily snapped into place on the carrier member <b>50.</b>

0023In use, the carrier <b>40</b> is mounted such that the carrier members <b>50</b> (and, in turn, the splice trays <b>62</b>) are generally horizontally disposed, with the splice trays <b>62</b> facing upwardly. Each carrier member <b>50</b> is free to move between an access position, in which the carrier member <b>50</b> is generally horizontal (see <b>Figures 3</b> and <b>6</b>) so that the splice tray <b>62</b> is accessible, and a partially inverted non-access position, in which the carrier member <b>50</b> has rotated about its respective axis of rotation <b>B1-B4</b> to be generally vertically disposed (see the rearwardmost carrier member <b>50</b> in <b>Figure 4</b>) so that the splice tray <b>62</b> is not accessible. As such, the carrier members <b>50</b> can be manipulated in "index card" fashion. Thus, in many respects the carrier <b>40</b> is quite similar to the carrier <b>20</b> illustrated in <b>Figures 1</b> and <b>2</b>. However, there are some differences that provide additional or alternative functionality to the carrier <b>40</b>; these are described below.

0024First, the presence of the frangible sections in the side walls <b>43</b> provides the carrier <b>40</b> with the capability of being modified as desired by the user for any number of splice trays <b>62</b>. For example, if the user wishes to use only three splice trays <b>62,</b> the user can simply break off one frangible section from each side wall <b>43</b> (for example, section <b>43d</b> as designated in <b>Figure 5</b>), which action would leave three pairs of pivot apertures <b>44</b> to receive three carrier members <b>50</b> and three splice trays <b>62.</b> Removing frangible sections as described can create additional space within the environment in which the carrier <b>40</b> resides or permit the carrier <b>40</b> to be used in a shallower enclosure.

0025Second, the inclusion of the latch <b>56</b> and nub <b>55</b> allow the carrier member <b>50</b> to capture the splice tray <b>62</b> without the use of an adhesive or other fastener. Because the latch <b>56</b> and nub <b>55</b> can be formed during the manufacture of the carrier member <b>50</b> (particularly if it is formed by the injection molding of a thermoplastic material), components for mounting the splice tray <b>62</b> on the carrier member <b>50</b> can be formed very inexpensively.

0026Third, the mounting apertures <b>47</b> on the mounting panel <b>46</b> can be can be utilized to mount the carrier <b>40</b>, typically via screws, other threaded fasteners, push rivets, or the like, to a vertical surface, as can be seen in <b>Figure 6</b>. Alternatively, a carrier <b>40</b>' may be configured for mounting to a horizontal surface (such as a shelf), as shown in <b>Figure 7,</b> via a mounting panel <b>46</b>' with apertures <b>47'</b>.

0027Fourth, the stair-step profile of the side walls <b>43</b> enables each carrier member <b>50</b> to be retained in the access and non-access positions as well as an intermediate position. The retention pins <b>60</b> of each carrier member <b>50</b> rest against the vertical edges <b>43a</b> of the side walls <b>43</b> (when the carrier member <b>50</b> is disposed as shown in <b>Figure 6</b>), which maintains the carrier members <b>50</b> in the access position. A slight force applied to the carrier member <b>50</b> urges it toward the non-access position; this force causes the retention pins <b>60</b> to deflect sufficiently to enable them to slide over the end of the horizontal edge to the detents <b>45</b>. This places the carrier member <b>50</b> in an intermediate position in which it defines an angle of approximately 45 degrees to the mounting panel <b>46</b> (see middle two splices trays <b>62</b> in <b>Figure 4</b>). From the intermediate position, resumption of the application of force to the carrier member <b>50</b> releases the retention pins <b>60</b> from the detents <b>45</b> and drives the carrier member <b>50</b> to the non-access position (see leftmost splice tray <b>62</b> in <b>Figure 4),</b> where the interaction between the retention pins <b>60</b> and the horizontal edges <b>43b</b> of the side walls <b>43</b> help to maintain the carrier member <b>50</b> in place.

0028Fifth, the offset or staggered positioning of the pairs of pivot apertures <b>44</b> (and, in turn, the positioning of the pivot axes <b>B1, B2, B3, B4</b>) can enable all of the carrier members <b>50</b> to overlie one another in stacked, substantially parallel relationship in both the access and non-access positions. This fully stacked relationship of the carrier members can be realized whether the base <b>42</b> is oriented either for wall mounting (see <b>Figure 6</b>) or floor mounting (see <b>Figure 7</b>), with the carrier members <b>50</b> being able to pivot from an access position to a non-access position in either orientation. Moreover, in some embodiments it may be possible for the carrier members <b>50</b> to be detached from the base <b>42</b>, inverted, and re-attached to the base <b>42</b> to enable the carrier <b>40</b> to be converted between wall and floor mounting.

0029The base <b>42</b> and carrier members <b>50</b> can be formed of the same materials discussed above for the carrier <b>20</b>. In addition, many of the design variations discussed above with respect to the carrier <b>20</b> may also be employed in the carrier <b>40</b>.

0030Referring now to <b>Figures 8-11</b>, another carrier of the present invention, designated broadly at <b>70</b>, is illustrated therein. The carrier <b>70</b> is formed from a flexible sheet (typically a flexible polymeric material such as polypropylene) that is folded back upon itself numerous times to form carrier members.

0031Referring first to <b>Figures 9-11,</b> the carrier <b>70</b> includes a plurality of carrier members <b>74</b> that are interconnected by intermediate panels <b>76.</b> Each carrier member <b>74</b> is formed of two overlying panels <b>74a, 74b</b> of a unitary flexible sheet <b>72</b> (see <b>Figure 11</b>). Each intermediate panel <b>76</b> is formed of the material of the flexible sheet <b>72</b> that resides between adjacent pairs of overlying panels <b>74a, 74b</b>, with adjacent intermediate panels <b>76</b> meeting at their edges to form an overall interconnecting member <b>79</b>. Thus, a living hinge <b>90</b> is formed at the fold lines between adjacent carrier members <b>74</b> and intermediate panels <b>76</b> that defines a pivot axis <b>C</b> for each of the carrier members <b>74</b>. The carrier <b>70</b> also includes a cover panel <b>78</b> with a flap <b>80</b> and a front panel <b>81</b>. A hook-and-loop fastener <b>82</b> is attached to the flap <b>80</b>, and a mating hook-and-loop fastener <b>84</b> is attached to the bottom panel <b>81</b>.

0032The carrier <b>70</b> is created by folding the flexible sheet <b>72</b> into a plurality of leaves to form the carrier members <b>74</b> and intermediate panels <b>76. Figures 10A</b> and <b>10B</b> show the configuration of the flexible sheet <b>72</b> (typically formed of polypropylene, although other flexible materials may also be employed) prior to folding. Designated fold lines <b>74c</b> separate the panels <b>74a, 74b</b> of each carrier member <b>74</b>, and designated fold lines <b>74d</b> separate the panels <b>74a, 74b</b> from adjacent intermediate panels <b>76</b>. The cover panel <b>78</b> is formed by folding the sheet <b>72</b> along fold line <b>78a</b>, and the flap <b>80</b> is formed by folding the sheet <b>72</b> along fold line <b>80a.</b> The front panel <b>81</b> is formed by folding the sheet along fold line <b>81a.</b> All of the aforementioned folds may be achieved through techniques known to those skilled in this art. The panels <b>74a, 74b</b> are attached to one another via double-sided adhesive sheets <b>75</b> (<b>Figure 10B</b>). Optionally, the carrier members <b>74</b> may be reinforced by sealing or otherwise attaching the edges of the panels <b>74a, 74b</b>; it may be particularly advantageous to seal the fold lines <b>74d</b> of adjacent panels <b>74a, 74b</b>, as doing so may improve the integrity of the living hinges <b>90</b> formed thereby.

0033Splice trays <b>86</b> are mounted to the panel <b>74a</b> of each carrier member <b>74.</b> In the illustrated embodiment, the splice trays <b>86</b> are attached via double-sided adhesive sheets <b>88</b> (see <b>Figure 10A</b>), although other attachment techniques may also be suitable.

0034When the carrier <b>70</b> is closed (<b>Figure 8</b>), the splice trays <b>86</b> and the carrier members <b>74</b> are in stacked, alternating, generally parallel relationship. The intermediate panels <b>76</b> (not shown in <b>Figure 8</b>) are disposed normal to the carrier members <b>74</b>. The cover panel <b>78</b> is parallel to the carrier members <b>74</b>, and the front panel <b>81</b> is normal to the carrier members <b>74</b> on the side opposite the intermediate panels <b>76</b>. The flap <b>80</b> overlies a portion of the front panel <b>81</b> such that the fastener <b>82</b> mates with the fastener <b>84</b>.

0035In order to perform work on a splice within the carrier <b>70</b>, a user would simply detach the flap <b>80</b> from the front panel <b>81</b> and rotate the cover panel <b>78</b> about its living hinge <b>90</b>. Doing so would present the uppermost splice tray <b>86</b> to the user. The user would then be free to rifle in "index card" fashion through the splice trays <b>86</b>, with each splice tray <b>86</b> moving from an access position to a non-access position via rotation about the living hinge <b>90</b> of its associated carrier member <b>74</b>, until the splice tray <b>86</b> of interest were reached.

0036Although the carrier <b>70</b> can be mounted in a number of orientations, it may be preferred to mount the carrier <b>70</b> to a horizontal surface, such as a shelf. If this is the case, one suitable orientation would have the splice trays <b>86</b> and carrier members <b>74</b> parallel to the mounting surface, with the cover panel <b>80</b> facing upwardly. It may also be advantageous to mount the carrier <b>70</b> to a vertical surface. If so, one suitable orientation would have the splice trays <b>86</b> and carrier members <b>74</b> parallel to the mounting surface, with the cover panel <b>80</b> facing forwardly and the intermediate panels <b>76</b> facing downwardly. In either of these orientations, detachment of the flap <b>80</b> from the front panel <b>81</b> can provide simple and convenient access to and manipulation of the splice trays <b>86</b>.

0037Turning now to <b>Figure 12</b>, the carrier <b>70</b> can be included in a shelf <b>110</b> on an equipment rack <b>100</b>. This particular shelf <b>110,</b> which is described in greater detail in coassigned and co-pending U.S. Patent Application No. <u>          </u>, filed <u>          </u> and entitled ARTICULATED HIGH DENSITY FIBER OPTIC SPLICE AND TERMINATION SHELF (Attorney Docket No. 9457-6), includes a splice site mounting panel <b>115</b> that is vertically oriented during normal operation and during maintenance of the carrier <b>70</b>. Fiber optic cables <b>120</b> feed into the carrier <b>70</b>, wherein splicing between optical fibers of the fiber optic cables <b>120</b> and pigtail fibers <b>125</b> is achieved. The pigtail fibers <b>125</b> lead to a termination device <b>130</b>, wherein they are optically connected with jumper fibers (not shown).

0038Those skilled in this art will recognize that other environments may also be suitable for use with the carriers of the present invention. For example, other splicing shelves, such as the 600 series family of shelves offered by SYSTIMAX Solutions, Inc., Richardson, Texas, may be employed. Alternatively, other structures, such as Interconnection Units (LIU) 100 or 200, also available from SYSTIMAX® Solutions, Inc., may also be used.

0039The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. As such, all such modifications are intended to be included within the scope of this invention. The scope of the invention is to be defined by the following claims.