Abstract:
Transportation of a lithographic plate uses an indexer to load plates into pods for delivery to a press cylinder via a pod elevator or a pod cart. The plates are imprinted with a bar code, imaged, punched, bent, sheared, corner notched, and registered to a press cylinder. The plates are loaded into the indexer, which moves the loaded plates into a position in alignment with designated pod compartments, and loads the plates into each of the designated pod compartments by indexed movement of an elevator within the indexer. The pod elevator or the pod cart moves the pods proximate to a press cylinder where the plates are unloaded from the pod and loaded onto a press cylinder. A computing device, such as a PLC, directs the process. A vision system senses information from the indexer, pod, pod elevator, and the plate for feedback to a PLC, which initiates all of the foregoing operations.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/808,083 filed May 24, 2006. 

   FIELD OF TECHNOLOGY 
   The technology disclosed in this specification is in the field of lithographic plate management and handling for web offset printing. The technology embodies a bar coded (or other coded) apparatus and process for transporting lithographic plates to a press cylinder. 
   BACKGROUND 
   The apparatus and process for transporting lithographic plates to a press cylinder described in this specification has particular (albeit not exclusive) application to management and handling of thin, flexible, lithographic printing plates in high rotational speed press operations. 
   An embodiment of an apparatus for transporting lithographic plates described herein is comprised of an indexer, a pod, and a pod elevator. Another embodiment of an apparatus for transporting lithographic plates is comprised of an indexer and a cart pod. 
   An embodiment of the process for transporting lithographic plates to a press cylinder most often operates in conjunction with an over-arching lithographic plate management and handling system. The system directs the operation of the indexer, pod, and pod elevator. Among other duties under its control, the system codes each plate. The code contains information, which the system PLC reads at various steps along the way of preparing lithographic plates for use on a printing press. The system uses the information to direct the plate along the correct and ultimate route to the printing press, including delivering the plate to an indexer, signaling the indexer to load the plate into various pod compartments, and using a pod elevator for transporting the plates to a press cylinder. 
   The indexer, pod, and pod elevator may be used to load, contain, and transport lithographic plates for web-offset printing, for non web-offset printing, or for non-printing applications. The operation of the indexer, the pod, and the pod elevator is described in this specification in conjunction with computerized system. However, the indexer, pod, and pod elevator may be operated without direction from a computerized system. 
   The web offset printing operation is highly automated. The heart of the operation is one or more high speed presses designed for efficient mounting and removal of lithographic plates. Each plate must be precisely mounted on the press&#39; plate-mounting cylinder to ensure that the lithographic plate image is in exact registration, i.e., “square” with the press cylinder when in the manufacturer&#39;s locked-up position. 
   In addition to the high rotational speed press—the hub of the operation—the printing operation must have a high speed means of management and handling of the lithographic plates. Management and handling includes identification of each lithographic plate in the system and on-time transportation of the plate to the press or presses. The means of identification and transportation of plates includes a plethora of modules, of which an indexer, pod, and pod elevator are a part. Such modules may perform (a) imaging and processing of plates, including bar coding of each plate for identification purposes; (b) image to plate registration and plate to cylinder registration; (c) plate punching, bending, shearing, corner notching/cutting; (d) direction of work flow and plate traffic routing, including optical registration verification, plate inspection, bar-code scanning, and remote diagnostics; (e) on-time delivery of plates to the press, including sorting, stacking, and conveying the plates (using, for example, plate entry modules, rotators, indexers, stackers, crossover bridges, elevators, thru-the-wall transport modules, dual highway modules, auto plate feeders, dummy plate loaders, and conveyors; (f) plate storage (in pods or on stacking cart pods), delivery of pods to storage, and rack storing of pods; and (g) automated retrieval from storage of the indexed plates. The identification and transportation of plates (and the modules which carry-out these functions) must be synchronized with one another and with the press to ensure that the plates are transported to the correct place at the correct time and the various operations on the plates are done timely and properly. 
   The competitive, low-margin economics of the printing business requires that the press not only be high speed, but so must the management and handling of lithographic plates. In this environment, the plate management and handling infra-structure must be fast, efficient, automated, and reliable to complement the printing process and workflow environment. The plate management and handling system employed cannot be allowed to contribute to press down time and image register problems. The system must ensure the continuous process flow of press-ready, in-register plates for each press cylinder with repeatable results. 
   The embodiments of the lithographic plate management and handling system of the present invention and its automated and synchronized, modular components are designed to meet these goals by integrating the entire printing workflow into one efficient system. The lithographic plate management and handling system feeds the press with the lithographic plates. The integrated system is designed to fully automate plate management and handling and reduce operator involvement in the printing process and workflow environment, whether it be in-line or off-line. Such integrated system spans the photographic process of imprinting an image on a lithographic plate to locking up the plate on the press. 
   The embodiments of an indexer, pod, and pod elevator and the other components of the system are all designed to automate the workflow of a printing production environment and to produce press-ready plates for applications using different levels of press technology, multiple press types, and multiple press register requirements. No one printing operation is the same, so the indexer, pod, and pod elevator and the other components of system are designed to be flexible in design and configuration. They are designed to be an integrated system with the flexibility to be custom-configured in many different ways. Moreover, the indexer, pod, and pod elevator and the other components of the system described herein range from fully automated to un-automated, depending upon the needs of a particular user application. 
   SUMMARY 
   The process for transporting lithographic plates uses an indexer to load plates into a pod compartment for delivery to a press cylinder. The plates are imprinted with a machine readable code, such as bar code. The process includes imaging and processing the plates and punching, bending, shearing, and corner notching the plates. Registration of the plate to a press cylinder occurs during imaging and bending the plate. Registration of the plates occurs when a plate can be precisely located on a press cylinder in accordance with the press manufacturer&#39;s plate lock-up specifications, including tolerances. 
   A conveyor moves the imaged plate to an indexer. The plates delivered to the indexer are already imaged, processed, punched, bent, sheared, and corner notched, as required, and in register. They are loaded into the indexer and the indexer moves the loaded plates into a position in alignment with designated pod compartments corresponding to bar code information. The indexer loads the plates into each of the designated pod compartment by indexed movement of the indexer&#39;s elevator to align the designated plates with each of the plates corresponding pod compartments. A pod elevator moves the pods proximate to a press cylinder where the plates are manually unloaded from the pod and loaded onto a press cylinder. 
   A computing device, such as a PLC, directs the process. The computing device has a memory for storing parameters corresponding to virtual locations of modules, such as a conveyor, the indexer, the pod, a pod compartment, a pod elevator, and a press cylinder. The computer stores physical locations of all of the plates at the various stages along the way to the press cylinder, machine readable codes on the plates, feedback information from the modules, and instructions for directing movement of the plates along routes based upon preset parameters. The computer includes a processor for executing the instructions, an input channel for receiving and storing the commands and the parameters, and an output channel for sending the instructions to a module for directing an operation and moving the plates along prescribed routes on a non-collision basis. A vision system is used for sensing information from a module and from a plate for feedback to a PLC, which initiates operations of a module and for bar-code scanning. 
   The plate indexer has a box frame, housing, elevator, indexer conveyor, plate centering assemblies, and plate finger pushers. An internal frame is secured to the box frame for support of the elevator. The elevator is vertically movable within the frame and the housing and in a first position the elevator is in a plate loading position and in a second position the elevator is in a plate exiting position. The elevator is raised and lowered by a drive motor having a worm gear assembly and a speed reduction adapter. The indexer conveyor has one or more horizontally, rollable conveyor belts and a means for rollably moving the belts. The plate centering assemblies include a means for pushing the plate into lateral registration with the belts. At least one assembly positioned on each longitudinal side of the plate. Finger pushers are mounted on each longitudinal side of the plate for gripping the plate with the finger springs and thereby move the plate into registration with the bed of the elevator. The plate assist assembly has a rodless cylinder mounted over the top of the indexer conveyor in a direction parallel to movement of the belts, a first a sensor for detecting the trailing edge of a plate and in response thereto the PLC signals the plate assist assembly to move the plate into a pod compartment and thereafter return to its start position. 
   The pod is a combination of a housing, partitioned compartments within the housing, a support bracket spanning the housing for rotatably mounting the pod in a pod elevator, a hangar for supporting a plate when the pod is in a vertical position within the pod elevator, a means for engaging a bend on the plate with the hangar, and a means for ejecting a plate from of the pod. The housing includes an enclosure, a retainer opposite the enclosure, the partitioned compartments between the enclosure and the retainer, and a support bracket spanning the enclosure, the compartments, and the retainer for rotatably mounting the pod in a pod elevator. 
   Each pod has multiple compartments, support brackets, hangars, a dual rod cylinder for engaging a bend on the plate, an ejecting for ejecting the plate. The compartments are vertically spaced apart parallel partitions. Upper pod support brackets are on an upper pod and lower pod support brackets are on a lower pod. The plates are loaded in a horizontal position. The assigned pod compartments are successively loaded with corresponding coded plates by incremental movement of the indexer elevator. 
   The pod elevator employed swivels the pods and their contained plates into a vertical position and transports the pods in a pod elevator proximate to a press cylinder. The support brackets have apertures for rotatable engagement with a pivot shaft of the pod elevator. A signal is sent to open a pod door, eject the plate from a designated pod compartment, and upon reaching the end of a plate ejector&#39;s travel retract the ejector to its home position. 
   The pod elevator transports the pods proximate the press cylinder. It is comprised of a frame, an outer carriage movable within the frame, an upper pod movable within the outer carriage, an inner carriage movable within the outer carriage, and a lower pod movable within the inner carriage. The frame is constructed of frame members, mounting frame members, back frame members, stabilizers, cross-members, and legs. The frame is built in two sections, which are a frame top portion and a frame bottom portion. The top portion is cantilevered over the bottom portion. The outer carriage is a combination of a frame with left and right side channels and top and bottom angle brackets, a guide rail affixed to the inside of the left channel, a guide rail affixed to the inside of the right channel, two guide roller assemblies mounted on the top angle bracket positioned to the left and right of the side channels, two guide roller assemblies mounted on the bottom angle bracket positioned to the left and right of the side channels, a cable cylinder mounted to the top and the bottom angle brackets and a cable attached to a top angle bracket of the inner carriage by a cable travel stop, a rotatable shaft in opposing end bearings, the bearings affixed to the left and the right side channels, a pivot affixed at one end in a pre-determined angular position to the shaft and rotatably connected at the other end to a cylinder and the top end of the cylinder rotatably connected to the bottom of the top angle bracket. The inner carriage includes a frame with left and right side channels and top and bottom angle brackets, four guide roller assemblies mounted on the top and the bottom angle brackets positioned outside of the left and right side channels, a shaft in end bearings, a pivot affixed between the shaft and a cylinder rod and the cylinder pivotally affixed to the top angle bracket. The pod elevator can have a number of pods within it, but the embodiment shown in this specification has two pods. Support brackets are on top of the upper pod and support brackets are on the bottom of the lower pod. The outer carriage has a rotatable shaft in opposing end bearings, the bearings affixed to left and right side channels and one end of a pivot affixed to the shaft in a pre-determined angular position, the other end of the shaft rotatably affixed to a cylinder, and the top end of the cylinder rotatably affixed to the top angle bracket. 
   An upper pod is rotatably affixed on the shaft by insertion of the shaft though apertures in the upper support brackets. The outer carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the upper pod 90° upward. 
   The inner carriage is comprised of a rotatable shaft in opposing end bearings, the bearings affixed to the left and right side channels and one end of a pivot affixed to the shaft in a pre-determined angular position, the other end of the shaft rotatably affixed to a cylinder, and the top end of the cylinder rotatably affixed to the top angle bracket. The lower pod is rotatably affixed on the shaft by insertion of the shaft though apertures in the lower support brackets. The inner carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the lower pod 90° upward. 
   The elevator has the following modes of operation: load plate mode, separate pod mode, rotate pod mode, lower pod mode, eject plate mode, and return home mode. 
   In the load plate mode, the upper pod is positioned horizontally on the upper shaft in the outer carriage, the lower pod is positioned horizontally on the lower shaft in the outer carriage, the bottom of the upper pod abuts the top of the lower pod, whereby the indexer can load the upper and lower pods as if they were a single pod. 
   In the separate pod mode, the horizontal upper pod remains stationary and the horizontal lower pod separate from the upper pod by movement of the inner carriage downward to the bottom of the outer carriage at least a distance from the outside of the channel shaped retainer to the outside of the enclosure. 
   In the rotate pod mode the upper and lower pods are rotated upward from their horizontal positions to vertical positions. 
   In the lower pod mode the outer carriage moves along with the vertical upper pod, towards the bottom of the elevator, the inner carriage, located at the bottom of the outer carriage, moves along with the vertical lower pod to the bottom of the elevator, wherein the upper pod remains in it vertical position about the vertically positioned lower pod. 
   In the eject plate mode designated plates are ejected from compartments in the upper and lower pods. 
   In the return home mode the elevator is directed to return to its home position for loading. The inner carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the lower pod 90°. 

   
     DESCRIPTION OF DRAWINGS 
       FIG. 1  is a diagrammatic view of an embodiment of a production line configuration of the system, which includes an indexer; 
       FIG. 2  is a perspective view of an embodiment of the indexer with its plate elevator in an up position; 
       FIG. 3  is a perspective view of an embodiment of the indexer with its plate elevator in a down position; 
       FIG. 4  is another perspective view of an embodiment of indexer with its plate elevator in an up position; 
       FIG. 5  is an exploded view of a portion of the embodiment of indexer illustrated in  FIG. 4 ; 
       FIG. 6A  is a perspective view of a conveyor module of an embodiment of the indexer of  FIG. 1 ; 
       FIG. 6B  is an exploded view of the conveyor module of an embodiment of indexer of  FIG. 1 ; 
       FIG. 7A  is a perspective view of plate assist assembly of an embodiment of the indexer; 
       FIG. 7B  is an exploded view of a plate assist assembly employed in an embodiment of the indexer; 
       FIG. 8  is a perspective view of finger pusher assemblies used in an embodiment of the indexer; 
       FIG. 9  is a perspective view of an embodiment of an upper pod, fully loaded with plates; 
       FIG. 10  is a perspective view of an embodiment of a lower pod, fully loaded with plates; 
       FIG. 11  is a perspective view of an embodiment of the upper pod with one partially loaded plate; 
       FIG. 12  is a perspective view of an embodiment of the lower pod with one partially loaded plate; 
       FIG. 13  is a perspective view of an embodiment of the upper pod shown without any plates loaded; 
       FIG. 14  is an exploded view of an embodiment of the upper pod; 
       FIG. 15  is a perspective view of an embodiment of the lower pod without any plates loaded; 
       FIG. 16  is an exploded view of an embodiment of the lower pod; 
       FIG. 17  is an exploded view of an embodiment of the upper pod partition and ejector; 
       FIG. 18  is an exploded view of an embodiment of the lower pod partition and ejector; 
       FIG. 19  is a perspective view of an embodiment of the pod elevator in the load plate mode; 
       FIG. 20  is a perspective view of an embodiment of the pod elevator in the pod separation mode; 
       FIG. 21  is a perspective view of an embodiment of the pod elevator in the rotate pod mode; 
       FIG. 22  is a perspective view of an embodiment of the pod elevator in the lowering pod mode; 
       FIG. 23  is a perspective view of an embodiment of the pod elevator in the ejecting plate mode; 
       FIG. 24  is a perspective view of an embodiment of an outer carriage of the pod elevator with the inner carriage in the up position; 
       FIG. 25  is a perspective view of an embodiment of an outer carriage of the pod elevator with the inner carriage in the down position; 
       FIG. 26  is an exploded view of an embodiment of the outer carriage of the pod elevator with the inner carriage in the up position; 
       FIG. 27  is a perspective view of an embodiment of inner carriage of the pod elevator; 
       FIG. 28  is an exploded view of an embodiment of the inner carriage of the pod elevator; and 
       FIG. 29  is a perspective view of an embodiment of the inner carriage of the pod elevator. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   System Level 
   The lithographic plate management system of the present invention is comprised of modules arranged in differing configurations to form myriad work flow arrangements. The main working modules are the imager  18 , image processor  9 , punch/bender  19 , indexer  2 , pod  3 , and pod elevator  4  ( FIG. 19 ). These modules are serviced by transport modules of various kinds. The system provides plate traffic control and tracking along the entire transport route. Some transport modules  8 , under control of a system PLC, transport plates forward or backward and right or left. They pause, hold, stop, start, slow down, speed up, rotate, index, sort, stack, elevate, or eject. The transport modules move press-ready plates to designated printing press locations. 
   Selected Modules 
   Plate indexer  2  receives the press-ready lithographic plates from belt transporter  8  or some other module in system  1  and loads each plate into a designated compartment of a pod  3  for delivery to the press. Pod  3  has several compartments that are separated from one another by parallel partitions, each of which is in a separate vertically spaced position. A pod elevator  4  moves the pods vertically from indexer  2  level to a second level on which the printing press is located. 
   A system controller (not shown) includes a programmable logic controller (PLC). It is the operating brain of system. It supervises the entire plate management and handling system. Among other things, it manages, monitors, and controls plate flow, system operation, alarms, and fault detection. It reports the need for preventative maintenance and does trouble-shooting. 
   Production Line Configurations 
   An embodiment of the lithographic plate management and handling system is illustrated in  FIG. 1 , a plan view. The main elements of system include imaging module  18 , plate rotation module (not shown), multi-directional plate transfer module to change the direction of flow of the plate after leaving the imaging module  18 , processor  9  for developing the image, a plate stacker, and a plate punch/bender module  19 . 
   Indexer 
   Indexer module  2  is part of an integrated group of devices for transporting, loading, ejecting, and orienting lithographic plates. Indexer  2  pushes plates into a container (a pod  3 ) in succession by moving a plate elevator incrementally as the plates are loaded into the pod by the pusher, resulting in plates being stacked in individual positions one above another as best seen in  FIG. 9 . The container or pod can be swiveled through an arc of 90 degrees. 
   After the printing plates pass through bender  19  (such as that described in U.S. Pat. No. 5,970,774) to form bends at the edges of the plate, they are placed sequentially on a multi-directional transporter, a dual lift up conveyor, or a belt transporter  8  and transported horizontally for delivery to indexer  2 . An embodiment of indexer  2  is shown in  FIGS. 2-3 . Plate indexer  2  receives the press-ready lithographic plates, one at a time, from belt transporter  8 , which is configured in-line with indexer conveyor  154  ( FIG. 6A ). Indexer conveyor  154  is a loading module. It loads each of the plates in a pod  3  (or a cart pod  3   a ) designated by a PLC in the system for delivery to the press. The constructional features of pod  3  are shown in  FIGS. 9-18 . As mentioned, pod has several compartments that are separated from one another by parallel partitions  219 , each of which is in separate vertically spaced positions. 
   As a plate begins to exit belt transporter  8 , it enters indexer conveyor  101  ( FIG. 2 ). A first sensor of indexer  2 , senses the entry of the leading edge of incoming plate and automatically initiates forward movement of the belts of indexer conveyor  101 . Indexer conveyor  101  operates at the same speed as does belt transporter conveyor  8 . Indexer conveyor  101  moves the plate to a position proximate a second sensor, which stops further plate movement. At the point when the plate is stopped, the plate is fully loaded into indexer conveyor  101 . Elevator motor  102 , operating under control of the PLC system controller, moves the indexer conveyor  101  vertically so that it (with encoded information on the plate, such as a bar code) is in horizontal alignment with the bar coded plate&#39;s assigned pod compartment. A look-up table in the memory of the system controller PLC is pre-programmed with an index of all of the compartments of pod  3 . The system controller associates each of the imprinted bar codes with a single one of the indexed compartments of each pod  3 . Typically, each of the printing plates moving within the system is imprinted with a bar code during, for example, the plate&#39;s initial entry into the system. Each indexed compartment is at a pre-determined vertical position of indexer  2  and that position is stored in system controller. In one embodiment, there may be 16 compartments. Therefore, for example, if a plate with bar code AAA is loaded into indexer conveyor  101 , the system controller PLC will sense the AAA bar code, associate it with the plate assigned to a particular compartment (9 th  compartment, for example), and signal elevator motor  102  to move the index conveyor up or down, as the case may be, to the 9 th  compartment. The now vertically moving index conveyor acts as an elevator and will sense when it has reached the vertical location of the 9 th  compartment by reference to the indexer&#39;s linear encoder, which senses conveyor/elevator&#39;s position, and will stop moving at the 9 th  compartment. At this juncture, plate pusher finger assemblies  106  (for example, 2 opposing assemblies proximate each side of plate) orient the plate so it&#39;s alignment on the plate conveyor elevator is in alignment with its assigned pod compartment. The plate is then ready for interference free movement into the assigned pod compartment. At the pre-determined vertical position, the system controller PLC signals the conveyor feature of the indexer conveyor/elevator  101  to begin forward movement of plate into its assigned compartment. When the trailing edge of the plate is sensed by the second sensor, the system controller signals the plate assist assembly  151  ( FIG. 7A ) to push the trailing edge of the plate fully into its compartment. After insertion of the bar coded plate into pod  3 , the system controller signals indexer conveyor/elevator motor  102  to return to the position associated with the belt transporter  8  level for receipt of another plate from the belt transporter  8 . The indexer handles one plate at a time. After receipt of the plate, the indexer conveyor elevator again begins its stepwise vertical movement under control of motor  102  until it reaches the designated compartment for the next plate, at which point the conveyor/elevator stops. As described previously, the next plate is placed in its respective indexed compartment and so begins anew the next series of cycles until a pod is fully loaded. 
   Indexer  2  is configured so that the PLC system controller can pause the operation of indexer  2  and thereby stop movement of press-ready plates already in indexer  2 . The system controller can also pause the operation of any conveyor  8  and thereby stop movement of any plate enroute to indexer  2 . The system controller is programmed to direct indexer  2  and other modules in the system when, for example, other plates are on a trajectory to intersect press-ready plates already in indexer  2  or enroute on a conveyor  8  to indexer  2 . In a highly configured system, the system controller may need to frequently control traffic due to multipathing of plates to multiple presses and the intersection of the multi-paths. The system controller thus acts like a stop and go light; stopping movement on some pathways while allowing movement on an intersecting pathway for higher priority plates for collisions avoidance. 
     FIG. 2  is a perspective view of an embodiment of indexer  2  with its conveyor/elevator  100  in an up position.  FIG. 3  is a perspective view of an embodiment of indexer  2  with its conveyor/elevator  100  in a down position.  FIGS. 2-3  illustrate indexer  4  with its conveyor/elevator  100  in-line with side horizontal frame members  110 A.  FIG. 4  is also a perspective view of an embodiment of indexer  2  with its conveyor/elevator  100  in an up position. 
   Indexer  2  is comprised of frame  114 , conveyor/elevator  100 , elevator drive system  102 B, indexer conveyor  101 , plate centering assembly  105 , and plate finger pusher assembly  106  ( FIG. 8 ). 
   An embodiment of frame  114  is a box frame, as shown in  FIGS. 2-3 , with side horizontal frame members  110 A, end horizontal frame members  110 B, vertical frame members  111 , and leveling pads  112 . Leveling pads  112  are adjustable for leveling indexer  2 . Horizontal and vertical frame members  110 A,  110 B, and  111  must be of an adequate size and have adequate strength to steadily support conveyor/elevator  100  and the other parts of frame  114  with little flexing. Tubular or square steel tubing is acceptable for this purpose. 
   Housing  113  is secured to frame  114 . Housing  113  provides an internal frame for conveyor/elevator  100 , elevator drive motor  102 B, and worm gear box  103 . Housing  113  comprises horizontal frame members  114 , vertical frame members  111 , side plates  116  ( FIG. 4 ), and drive motor support  117  ( FIG. 2 ). 
   Elevator  100  is movable vertically within frame  114  and housing  113 . Elevator  100  is formed of lightweight side box beams  124 A and end box beams  124 B ( FIG. 3 ) with a plurality of spaced-apart parallel top cross members  127  extending laterally between parallel side box beams  124 A for lateral strength. Elevator  100  can be in a down position to receive a lithographic plate and then raised to an elevated position for exiting the plate from indexer  2  into a selected compartment of pod  3  or plate rack  10  for delivery to the press. Alternatively, elevator  100  can be in an elevated position to receive a lithographic plate and then lowered to a down and/or up position for exiting the plate from indexer  2  into pod  3  or plate rack  10  for delivery to the press. 
   The elevator drive system raises and lowers elevator  100 . As seen in  FIG. 5 , it is comprised of drive motor  102 B, 4:1 helical adapter  147 , worm gear box  103 , drive shafts  120 A and  120 B, bearings  142 A and  142 B, side plates  116 A and  116 B, spacer plates  135 A and  135 B, taper lock adapters  143 A and  143 B, upper drive belt pulleys  118 A, lower drive belt pulleys  118 B, open drive belt  109 , open drive belt clamp plate  119 , open drive belt clamps  166 , side plate  160 , single split collar  141 , taper lock idler  149 , idler mount  134 , take-up bolt  136 , take-up mount  133 , top plate  121 , linear shafts  108 , linear shaft mounting block  137 , and linear bearings  107 . 
   Drive motor  102 B, an AC motor, is connected to 4:1 helical adapter  147 , which reduces the drive motor&#39;s speed to ¼ its output rpm. The output of 4:1 helical adapter  147  is delivered to worm gear box  103  and then to drive shafts  120 A and  120 B. Drive shafts  120 A and  120 B run in bearings  142 A and  142 B. Bearings  142 A and  142 B are mounted on the backside of side plates  116 A and  116 B. Spacer plates  135 A and  135 B offset side plates  116 A and  116 B inwardly from frame  114  for clearance from outside of frame  114 . Drive shafts  120 A and  120 B extend through an aperture in each side plate  116 A and  116 B and are engaged by taper lock adapters  143 A and  143 B, which are affixed inside lower drive belt pulleys  118 B. Open drive belt  109  engages upper and lower drive belt pulleys  118 A and  118 B. Upper drive belt pulleys  118 A include taper lock idlers  149  fixedly engaged within the hubs of upper drive belt pulley  118 A. Shaft  134 B of idler mount  134 A rotatably extends through apertures in taper lock idlers  149  and is held in place by single split collars  141 . Idler mounts  134 A are held in place by take-up mounts  133 , which are affixed to horizontal frame members  110  and to top plates  121 . Top plates  121  are also affixed to horizontal frame members  110 A. Take-up bolt  136  is adjustable to increase or decrease tension in open drive belts  109  and it extends through top plates  121  for easy access. The ends of open drive belt  109  attach to open drive belt clamp plate  119  and are clamped to open drive belt support  119  by open drive belt clamps  166 . Open drive belt clamp plate  119  is attached to elevator  100 . Motor drive shafts  120 A and  120 B protrude through side plates  116 A and  116 B and connect with their respective upper and lower drive belt pulleys  118 A and  118 B. Side plates  116 A and  116 B are attached to vertical housing members  115  at the bottom of the vertical housing members. Each linear shaft  108  is fixed at its ends within a mounting block  137 , so that it neither rotates or moves vertically. Linear bearings  107  are attached to elevator  100 . Each linear shaft  108  rides within two linear bearings  107  allowing elevator  100  to move smoothly in a vertical direction. Upper drive belt pulleys  118 A and  118 B are indirectly attached to upper horizontal housing members  114 . Elevator drive motor  102  is seated on drive motor support  117  and fastened to horizontal frame member  114 . Motor drive shafts  120 A and  120 B extend from each side of elevator gear drive box  103  and extend through side plates  116 A and  116 B and into lower drive belt pulleys  118 A and  118 B on each side of indexer  2 . Elevator drive motor  102 B is configured with 60:1 speed reducer  147  for transmission of power from its armature, which is contained in drive motor  102 B housing. 
     FIGS. 6A-6B  best illustrate indexer conveyor  154  of conveyor/elevator  100 . A series of web pulleys  125  are affixed to drive shafts  126 . The ends of each drive shaft  126  are rotatably affixed into bearings  128 . Bearings  128  are affixed to side box beams  124 A parallel to top cross members  127  near end box beams  124 B. The two web pulley  125 /drive shaft  126  combinations are mounted near each end box beams  124 B and in parallel to each, so flat web belts  104  can be rollably affixed to in-line web pulleys  125  near each end box beam  124 B. Flat web belts  104  move around web pulleys  125  in parallel with side box beams  124 A and other web pulleys  125 . Web pulleys  125  move longitudinally by chain drive  130  connected to sprockets  131  on drive shafts  126 . Chain drive  130  is driven by an electric motor (not shown). 
   Plate centering assembly  155  ( FIG. 6B ) is mounted perpendicular to side box beams  124 A. It may be comprised of a pneumatic or electrical actuator assembly. The push rod of a pneumatic actuator moves the lithographic plate laterally after it enters onto conveyor/elevator  100 . In one embodiment, there are four plate centering assemblies  105 . The number of plate centering assemblies depends to some extent upon the size of the plate. Smaller plates may be centered by two or three such assemblies. Indexer  2  is programmed so that each of the plate centering assemblies  105  work in conjunction with one another to move the plate in a lateral registration position. After the plate has entered indexer  2 , plate finger pusher assembly  106  ( FIG. 4 ) adjusts the position of a plate on bed conveyor  132  of conveyor/elevator  100  to be in registration with the bed. The registration position on the bed is established so that when the plate begins to be ejected from indexer  2  it will travel in a pre-set direction within the ambit of a defined path that is in-line with the entry point of a designated compartment of pod  3 . If the plate is not in registration, it may jam within indexer  2  or with pod  3  as it is ejected from indexer  2 . 
   Plate finger pusher assemblies  106 A and B are best illustrated in  FIG. 8 .  FIG. 8  is a perspective view of assemblies  106 A, of which there are three, and is an exploded view of assembly  106 B, of which there is one. Assemblies  106 A and  106 B are identical to one another. Two assemblies  106  are mounted on each side of the lithographic plate and move the plate for proper positioning on the bed of indexer  2 . Assembly  106  is comprised of dual rod cylinder  171 , finger spring  168 A, finger spring block  168 B, cylinder bracket  169 , and flow control fitting  170 . Two finger pusher assemblies  106  are attached to each side box beam  124  of elevator  101  by cylinder bracket  169 , as shown in  FIG. 4 . Dual rod cylinder  171  is operated pneumatically. Flow control fitting  170  has a port, the size of which is manually adjustable by a port handle to decrease or increase the amount of air entering the cylinder and thereby driving the movement of the cylinder. Too much air may over-drive the rod and damage the plate. Too little may not move the plate into position. Finger spring  168 A is a compliance spring. It is attached to block  168 B. It introduces some give or resiliency when it connects with the plate so the plate will not be damaged. V-portion  168 C is the contact point with the plate. 
   Plate assist assembly  151  is illustrated in  FIGS. 7A-7B . When the trailing edge of a plate is sensed by second sensor  185 , the system controller not shown signals plate assist assembly  151  to push the trailing edge of the plate fully into its compartment  200 . Plate assist assembly  151  is mounted over the top of indexer conveyor/elevator  101 . Plate assist mounts  153 B are mounted between side box beams  124 A on elevator  100 . A rear plate assist mount  153 B is mounted proximate the plate exit point of indexer conveyor/elevator  101  and the front plate assist mount  153 B is mounted proximate the center of indexer conveyor/elevator  101 . Rodless cylinder mounts  172  are affixed on plate assist mounts  153 B at the center-line of each mount  153 B and rodless cylinder  179  is mounted to rodless cylinder mounts  172 . Rodless cylinder  179  is mounted in a direction parallel to movement of flat web belts  104  on indexer conveyor bed  154 . Base cylinder mount  174  is affixed to rodless cylinder  179  and slides forward from its position near centrally disposed front plate assist mount  153 B when the system controller signals it to push a plate into its respective compartment  200 . A pusher assembly is mounted to base mount cylinder  174  at its leading edge when pushing a plate. The pusher assembly is comprised of two pusher blocks  177 , respective cylinders  182 , respective cylinder mounts  175 . When base cylinder mount  174  moves a plate into compartment  200 , it passively pulls electrical conduit chain  180  with it. When base cylinder mount  174  completes its task of pushing a plate into compartment  200 , electrical conduit chain  180  deliveries the signal to rodless cylinder  179  to return to home at its start position in readiness for pushing the next plate. Electrical conduit chain  180  is supported by chain guide  176 . Electrical conduit chain  180  is connected at one end to the top of base cylinder mount  174  and at the other end to the bottom of chain guide  176 . Each end is connected to their respective locations by small brackets  181 . 
   Pod 
   As will be illustrated with respect to an embodiment of pod elevator  4  described infra, pod elevator  4  has two pods which are integral parts of pod elevator  4 . 
   Pod  3  of  FIG. 1  is more particularly shown in  FIGS. 9-18  and comprises a container that receives bar coded plates from indexer  2  (the pod loading machine) and loads the pod with the plates. The plates are loaded in a horizontal position. Pod  3  is then transported to a station in close proximity to a printing press. A press person extracts each plate from the pod, one by one, and locks-down each plate on the selected press cylinder. Pod  3  has several compartments  200  that are separated from one another by parallel partitions  201  (consisting primarily of rails  219 , see in  FIG. 11 ), each of which are in separate vertically spaced positions. Indexer  2  loads the bar coded plates into the various compartments  200  of pod  3 , as designated by the system&#39;s PLC, in succession by moving indexer elevator  100  incrementally up or down until it is in horizontal alignment with the bar coded plate&#39;s assigned pod compartment  200 , resulting in plates being stacked in individual compartments  200 , one above another. In one embodiment of pod  3 , there are 16 compartments  200 . 
   Pod  3  can be integrated with a pod elevator  4  shown in  FIGS. 19-23  for movement of the plates stored in pod  3  to the press. Pod  3  is in a horizontal position in pod elevator  4  after it is loaded with plates. The pod can then be swiveled through an arc of 90° to bring it into a vertical position within the pod elevator  4  for vertical movement by the pod elevator  4 . The plates ride within pod  3  in an upright-vertical position, suspended by a bend along one edge of the plate, the bend having been made by punch/bender  19 . Vertically hung pod  3  is transported (lowered or raised, as the case may be) by pod elevator  4  to a station where the plates contained therein will be manually removed and loaded onto a designated press cylinder by a press operator, according to each plate&#39;s bar coded information. 
   Each parallel compartment  200  of pod  3  is provided with a plate hanger  202 . Plate hangar  202  is designed to enable the relatively fragile plates to be rotated 90° from their horizontal positions to vertical positions without damage to the plates and image thereon. After rotation, the plates are automatically suspended on hangers  202  (FIG.  17 ) in vertical positions. Hangers may be made of a plastic material for avoidance of plate scratching. Hanger  202  is affixed longitudinally to enclosure base  223 . Hanger  202  is comprised of a top bracket  202 A connected to an angled bracket  202 B. Top bracket  202 A is in-parallel with the bottom surface of the plate and the bottom surface of the plate rests on top bracket  202 A. Projecting downward from top bracket  202 A and from the bottom surface of the plate is angled bracket  202 B. Angled bracket  202 B projects downward at an angle that is over 90° from top bracket  202 A to form an anvil shaped hanger assembly  202 . The bend formed along one edge of the plate is tucked around the point where the top bracket  202 A and the angled bracket  202 B meet, thereby hooking the anvil shaped bend on the edge of the plate over hanger  202 . 
     FIG. 9  is a perspective view of an embodiment of upper pod  3 , fully loaded with plates.  FIG. 10  is a perspective view of an embodiment of lower pod  3 , fully loaded with plates.  FIG. 11  is a perspective view of an embodiment of upper pod  3  with one partially loaded plate.  FIG. 12  is a perspective view of an embodiment of lower pod  3  with one partially loaded plate extending outward from a front end portion of the pod. Enclosure  217  ( FIG. 9 ) is comprised of base  233 , cover  214 , and two end caps  205 . Opposite enclosure  217  is channel shaped retainer  208  ( FIG. 10 ). Enclosure and channel shaped retainer are tied together by a support member  226  affixed from a first end of enclosure  217  to a first end of channel shaped retainer  208 . Another support member  226  is affixed in the same manner between the second end of enclosure  217  and the second end of channel shaped retainer  208 . Two L-shaped supports  206  extend, in parallel, across the top of pod  3  and provide rigid transverse bracing between enclosure  217  and channel shaped retainer  208 . L-shaped supports  206  are respectively affixed at their ends to enclosure cover  214  and to the top of channel shaped retainer  208 A and to the face of channel shaped retainer  208 B. A plurality of curvilinear rails  219  are connected between support members  226  at both ends of pod  3 . Curvilinear rails  219  support the lithographic plates and form the partitions  201  between the compartments  200  of the pod. Each compartment  200  comprises a separate envelope for a separate plate. 
   Facing mounting blocks  207  are affixed to those portions of L-shaped supports  206  that are in contact with channel shaped retainer  208 . Mounting blocks  207  provide rigidity to that portion of the L-shaped supports  206 . Mounting blocks  207  also include keyless hubs  209  with apertures for insertion of pivot shaft  310  between opposing keyless hubs  209 . As will later be explained, pivot shaft  310  is used by a pod elevator  4  to vertically move pod  3 . 
   Two dual rod cylinders  212  ( FIG. 9 ) are mounted in enclosure  217 . Both cylinders  212  act to gently push the plate towards channel shaped retainer  208  and bring the apex of the anvil shaped bend of the plate in mating contact with the apex of anvil shaped hanger  202 A. The effect is that the plate is held firmly in place in pod  3  during movement of the pod and damage to the plate is virtually eliminated. 
     FIG. 13  is a perspective view of an embodiment of upper pod  3  without any plates loaded.  FIG. 14  is an exploded view of an embodiment of upper pod  3 .  FIG. 15  is a perspective view of an embodiment of lower pod  3  without any plates loaded.  FIG. 16  is an exploded view of an embodiment of lower pod  3 . 
     FIG. 17  is an exploded view of an embodiment of the partition and ejector of upper pod  3 .  FIG. 18  is an exploded view of an embodiment of the partition and ejector of lower pod  3 . Partition  201  is comprised of six curvi-linear rails  219 . The rails  219  are connected to transverse rail supports  226  at the first and second ends of pod  3  with snap lock clips  227 . Snap lock clips  227  are fastened to rail supports  226  and the ends of rails  219  are snapped into the top of snap lock clips  227 . As shown in the figures, pinch lock clips  230  hold rails  219  together in pairs at the point where rails  219  abut one another. Support shaft  233  extends transversely across rails  219 . Pinch lock clips  230  are spaced on shaft  233  so each clip  230  locks onto a single rail  219  where rails  219  abut one another. The spacing is shown in  FIGS. 17-18 . Spacing is maintained by round spacers  229  lying in between the spacers on support shaft  233 . As shown in the figures, there are three such support shafts  233  supporting each of the partitions. However, there can be more or fewer shafts depending upon the length of the rails/partitions. A T-clamp  228  is attached to hanger  202  at the end of support shaft  233  and tied into channel shaped retainer  208  ( FIG. 14 ). The top of hanger  202  is in the same plane as the top of rails  219 . 
   A plate ejector  215  ( FIG. 17 ) is comprised of a single rod cylinder  225  and mounting bracket  232 . The cylinder is mounted on mounting bracket  232  and the bracket is affixed to support member  226  on the second end of each pod compartment  200 . Ejection cylinder  215  extends in a direction from the second end of each pod compartment  200  to the first end of each pod compartment  200 . As the ejection cylinder  215  is extended it ejects the plate from its compartment towards the second end of pod  3 , one at a time, into the hands of a printer who will place the plate on the press cylinder. Plate ejector cylinder  215  retracts its piston  225  upon reaching its maximum travel point. To eject the plates, the printer signals the system controller to open a pod door. When the pod door opens, plate ejector  215  associated with a designated compartment  200  dispenses the plate from that compartment into the hands of the printer. 
   Pod elevator  4  can be scaled up or down to move more or less than two pods  3 . The basic configuration of pod elevator  4  is the same regardless of pod capacity, except that the size of elevator  4  is scaled up or down (in for example, its height, pod capacity, or the size of the lithographic plate) to meet the needs of a customer&#39;s pre-press configuration. 
   Cart Pod 
   The cart pod (not shown) serves a similar function as does the previously described pod, albeit in a less automated manner. Primarily the cart pod is less automated because it cannot interface with the pod elevator and it is generally a wheeled device. It does however fully interface with the indexer and is loaded by the indexer in the same manner the indexer loads the pod. Once it is loaded with plates it is transported proximate the press cylinder, where the plates are unloaded and locked-up on a press cylinder. The cart pod is configured to be loaded with plates one at a time by the indexer. The configuration includes dimensional attributes that allows the cart pod to be in alignment with the pusher end of the indexer as if it were a pod. In this manner the pusher end of the indexer is in-line compatible with the cart pod. Moreover, the cart pod is configured to accept the same size plates as does the pod. The pusher assembly of the indexer pushes the plate into the cart pod in the same manner as it does with the pod. The cart pod also has separate vertically spaced compartments as does the pod. The indexer pushes plates into the separate cart pod compartments in succession by lowering the plates relative to the compartments incrementally as the plates are loaded by the pusher assembly, whereby the plates become stacked in individual positions one above another. Parallel partitions separate the cart pod into pod compartments. The elevator moves a plate in a vertical direction into horizontal alignment with the cart pod compartment that corresponds to a code on the plate. The compartments are indexed at a pre-determined vertical position of the indexer. A linear encoder senses the point at which the elevator has reached a specified vertical location corresponding to the assigned cart pod compartment, at which point the elevator stops. Pusher finger assemblies proximate each side of the plate align the plate with the elevator and the assigned cart pod compartment. Upon completion of alignment of the plate with the elevator and assigned cart pod compartment the indexer conveyor initiates forward movement of the plate into the assigned cart pod compartment and upon sensing the trailing edge of the plate by the second indexer sensor means, a plate assist assembly pushes the trailing edge fully into the assigned cart pod compartment. 
   Pod Elevator 
   The structure of pod elevator  4  is described, followed by the description of its operation. 
     FIG. 19  best illustrates the frame of pod elevator  4 . The frame is comprised of multiple frame members  300 ,  300 A,  300 B and  300 C. These frame members form the skeleton of pod elevator  4 . Pod elevator  4  is most often mounted to a wall by mounting pads  304 . To assure stability, pod elevator  4  is also floor-mounted by, for example, bolting the elevator into the floor through mounting frame members  300 A. The top and bottom portions of elevator  4  are bolted together through top assembly pad  305 A, located at the end of back frame member  300 B of the top portion, and through a bottom assembly pad, located at the end of back frame member  300 B of the bottom portion. The bottom portion of elevator  4  also has two front, upward extending legs  300 C, each with an assembly pad which are bolted together. The top portion of elevator  4  is cantilevered over the bottom portion. The bottom portion of elevator  4  is sized to fit through an opening provided in a first floor ceiling of a two-story building. The cantilevered top portion is above the ceiling and bolted to the bottom portion of elevator  4 . The top portion has a larger footprint than that of the bottom portion. Diagonal stabilizers  303  strengthen elevator frame members  300  and act as sway bracing, among other things. 
   The operating parts of pod elevator are outer carriage  301  and inner carriage  302 .  FIGS. 24-26  illustrate the structure of outer carriage  301  and to some degree, inner carriage  302 .  FIG. 24  illustrates inner carriage  302  in an up-position relative to outer carriage  301 .  FIG. 25  illustrates inner carriage  302  in a down-position relative to outer carriage  301 .  FIG. 26  is an exploded view of the structure of outer carriage  301  and to some degree, inner carriage  302 .  FIGS. 27-29  illustrate inner carriage  302 . 
   The exploded view of  FIG. 26  best illustrates the structure of outer carriage  301 . The frame of outer carriage  301  includes bottom angle bracket  318 , left and right side channels  317 , and top angle bracket  315 . Each frame member is securely bolted or welded together. Left and right guide rails  319  are affixed to the insides of left and right side channels  317  and run more or less the full length of left and right side channels  317 . Four guide roller assemblies  316  lie outboard of side channels  317 ; a pair mounted on the top of bottom angle bracket  318  and a pair on the bottom of top angle bracket  315 . Shock absorbers  329  are mounted on shock mounts  320  at the top and the bottom of guide rails  319 . They project upward from the bottom of the guide rails  319  and downward from the top of guide rails  319  to absorb whatever light shock may occur when inner carriage  302  bottoms out at the end of its downward travel along guide rails  319  and when it tops out at the end of its upward travel along guide rails  319 . Cable cylinder  306 A is attached to bottom angle bracket  318  by intermediate mount  307 . Mount  307  offsets cylinder  306 A from bracket  318  to allow clearance between inner carriage  302  and the cable cylinder. Likewise, cylinder plate mounts  312  perform the same function at the top of cable cylinder  306 A. Cable  313 A is attached to the top angle bracket of inner carriage  302  by cable travel stop  313 B so that cable cylinder motor  306 B is able to move inner carriage  302  up and down within outer carriage  301  as and when signaled to do so by the system PLC (not shown). 
     FIGS. 27-29  illustrate inner carriage  302 . Inner carriage  302  is similar in certain respects to outer carriage  301 . Inner carriage  302  is comprised of left and right side channels  333 A and  333 B. Each channel has mounting bracket at its top and bottom for mounting channels  333 A and  333 B to top angle bracket  331  and to bottom angle bracket  332 . Guide roller assemblies  336 B are affixed to the top surface of bottom angle bracket  332  and to the bottom surface of top angle bracket  331 . With reference to  FIG. 28 , guide roller assemblies  336 A include rollers  336 B and mounting brackets  336 C on which rollers  336 B are rotatably affixed. Shaft  334 A has bearing  335 A at each end. Each bearing has a mounting flange  335 C. Mounting flanges  335 C are attached to bearing mounts  335 B, which in turn are affixed to side channels  333 A. Pivot  334 B is affixed to shaft  334 A between bearings  335 A. Pivot arm  334 B is connected to the cylinder rod of cylinder  330 A by a cylinder attachment assembly. This assembly includes, for example, a threaded bolt fitted through an aperture  337 C in a cylinder rod end, a spacer  337 D, and an aperture  337 E in pivot arm  334 B. Cylinder  330 A is attached to a clevis mounting plate inserted by pin  338 B through eyes  338 B of cylinder  330 A and through eye  338 D of clevis mounting plate  338 A. Mounting plate  338 A is mounted to the bottom of top angle bracket  331 . 
     FIGS. 19-23  illustrate pod elevator  4  with two pods  3  mounted therein. Pods  3  are initially stacked horizontally in elevator  4 , prior to putting the elevator in service. The pods are an integral part of elevator  4 . They are not intended to be removed in the normal course of the printing operation. However, the pods can be removed with little difficulty and used to store the lithographic plates for use at a later time. 
   As previously mentioned and as shown in  FIG. 19 , an embodiment of elevator  4  has two pods  3 . The upper pod is held by outer carriage  301  of  FIG. 24 . The lower pod is held by inner carriage  302 . L-shaped supports  206  can be seen on the top of the upper pod.  FIG. 26  shows shaft  310 A. The shaft extends through keyless hubs  209  in each L-shaped support of the upper pod. Shaft  310 A is rotatably held in bearings  326 , which are affixed to left and right side channels  317  of elevator  4  ( FIGS. 24-26 ). Shaft  310 A inserts into an aperture in one end of pivot  310 B of the upper pod and is non-rotatably affixed in the angular position shown in  FIGS. 24 and 26 . Cylinder rod  325 B of cylinder  325 A is rotatably connected to pivot arm  310 B at the other end of pivot  310 B. The top end of cylinder  310 A is pivotally connected to the bottom of top angle bracket  315 . When cylinder  310 A is actuated by the system controller, rod  325 B moves downward, rotates shaft  310 A clockwise 90°, and likewise rotates upper pod  3  clockwise 90°. Shaft  310 A rotates pod  3  clockwise 90° due to the fact that shaft  310 A is gripped by the two keyless hubs  209  on pod  3 . The clockwise rotation of pod  3  around shaft  310 A forces enclosure  217  of the upper pod to also rotate 90° with the result that the formerly horizontal upper pod is now vertical with enclosure  217  above channel shaped retainer  208 , as can be seen in  FIG. 21 . Rotation of the lower pod occurs in the same manner as for the upper pod. The difference is that lower pod  3  is pivoted around shaft  334 A of inner carriage  302  rather than shaft  310 A of outer carriage  301 . Lower pod is also oriented differently than upper pod, in that L-shaped supports  206  are on the bottom of lower pod  3 . L-shaped supports  206  mounted in this manner so that the two pods are abutting one another in the load plate mode. When abutting, the spacing of the partitions of pod  3  are close enough together so that the upper and lower pods appear to indexer  2  to be a single larger pod. This allows for more efficient loading of the two pods by indexer  2 . 
   The operation of elevator  4  includes six sequential modes. 
   The first mode shown in  FIG. 19  is the “load plate” mode. In the load plate mode, indexer  2  loads bar coded plates into an identified compartment  200  of an identified pod  3 , of which there are two. Prior to loading the plates, a bar code reader on indexer  2  reads the bar code of the plate to be loaded. Identifiers for pod  3  and for the compartment  200  (in which the plate will be loaded) in identified pod  3  are sensed by magneto-resistive transducer  144  mounted on indexer  2 . Transducer  144  senses each indexed position of the indexer&#39;s elevator  100  as it moves upwardly or downwardly within indexer housing  113 . Each indexed position corresponds to the position of a specific compartment  200  in a specific pod  3 . The identifier for the compartment, the identifier for the pod, and the bar coded information on the plate is fed back to the system PLC of the plate management and handling system and are stored in the PLC&#39;s memory. As shown in  FIG. 19 , upper pod  3  is hung on outer carriage  301  by shaft  310 A and is affixed to shaft  310 A by keyless hubs  209  of upper pod  3 . Lower pod  3  is hung on inner carriage  302  by shaft  334 A and is affixed to shaft  334 A by keyless hubs  209  of lower pod  3 . 
   The second mode shown in  FIG. 20  is the “separate pod” mode. In this mode, adjacent upper and lower pods  3  of  FIG. 19  are vertically separated. During separation, upper pod  3  remains stationary in the load plate position. Upper pod  3  is connected to outer carriage  301 , which consequently also remains stationary. Lower pod  3  is connected to inner carriage  302 . Inner carriage  302  rides within outer carriage  301 . Separation of lower pod  3  from upper pod  3  occurs when inner carriage  302  moves downward within outer carriage  301 . Inner carriage  302  moves downward when it receives a signal do so from the system PLC. Upon receiving the signal, inner carriage  302  is moved down to the bottom of outer carriage  301  by inner carriage cable  313 A and its associated parts, comprising four inner carriage cable roller assemblies  336 A, inner carriage cable attachment point  313 B, inner carriage cable cylinder  306 A, and inner carriage cable motor  306 B. Inner carriage  302  rides up and down on inner carriage rails  319 A and B. Rails  319 A and B are captured by the three guide rollers  336 B of guide roller assembly  336 A. The lower pod is separated from the upper pod by at least a distance equal to the width of pod  3 . The width of pod  3  is defined by the distance from the outside of channel shaped retainer  208  to the outside of enclosure  217 . During and initially after pod separation, the pods remain in a horizontal position. 
   The third mode shown in  FIG. 23  is the “rotate pod” mode. In this mode, as previously described, each pod is rotated upwards 90° from its horizontal orientation to a vertical orientation. 
   The fourth mode shown in  FIG. 24  is the “lower pod” mode. In this mode, both of the vertically hung pods of  FIG. 23  are moved downwards to the bottom of elevator  4 . Downward movement of both of the pods occurs simultaneously by downward movement of outer carriage  301 . Outer carriage  301  contains inner carriage  302  and its associated pod. Inner carriage  302  was moved in the lowest position within outer carriage  301  during the “separate pod” mode. Outer carriage  301  moves downward when it receives a signal from system controller to do so. Upon receiving the signal, outer carriage  301  is moved down to the bottom of pod elevator  4  by outer carriage cable  308 B and its associated parts, comprising four outer carriage cable roller assemblies  316 , outer carriage cable attachment point (not shown), outer carriage cable cylinder  308 A, and outer carriage cable motor  308 D. Outer carriage  301  rides up and down on outer carriage rails  319 . Rails  319  are captured by guide roller assemblies  316 , which are each comprised of 3-rollers. 
   The fifth mode shown in  FIG. 25  is the “eject plate” mode. After the pod elevator&#39;s delivery of the plate to a press area, the system controller sends the plate&#39;s bar coded information and identifiers for compartment  200  and pod  3  (sometimes referred to as the plate address) to the press-person. The information is most conveniently provided on an electronic display. Among other information, the information tells the press-person on which cylinder the ejected plate is to be placed. In this mode, the press-person signals the system controller to eject the identified plate out of its pod compartment  200  into the hands of the press operator. The press operator then locks the plate on the cylinder designated by the information sent to the display by the system controller. 
   The sixth mode is the “return home mode.” In this mode, the system controller directs pod elevator to return to its home position for further loading of the pods by indexer  2 . The sixth mode reverses the sequence of the previously described five modes. 
   Although the apparatus for loading lithographic plates into a container for transport to a press cylinder and the process thereof have been described with reference to the embodiments, those skilled in the art will recognize that numerous changes may be made in form and detail without departing from the spirit and scope of the apparatus and process.