Abstract:
Method and apparatus for water jet cutting parabolic shaped segments that support reflective surfaces of a concentrating solar collectors. Apparatus describes corrugating machine cutoff, parabolic curve water jet cutters longitudinal slitters, transfer/diverters, and stackers. Parabolic curve cutting involves at least one cutter on a first transverse path with means for reversing movement over a moving web in cooperation with a cutter on a parallel second path with means for mirror image movement to make a pair of opposite curves which intersect at segment ends. Jet cutter reversing servo motor drive means programmable for different parabolic curves. Includes use of plurality of cutter pairs to make segments with multiple parabolic curves per length. Apparatus includes means to make standard corrugated board or parabolic segments by electronic switching without machine adjustments.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION  
       [0001]     Because solar radiation emits low levels of energy, very large areas are required for collection and concentration. The instant invention involves high speed production of corrugated paperboard parabolic segments as supports for a reflective surface in a concentrating trough collector.  
         [0002]     Numerous corrugating machines worldwide can be adapted to produce parabolic segments in addition to regular corrugated board segments for cartons.  
         [0003]     Stationary water jet cutters made by Flow Industries Inc of Kent Wash. and Ingersoll Rand are well known and used extensively to slit full width webs into a plurality of narrower webs at speeds over 350 ft/min with linear cuts from high pressure water jet cutters.  
         [0004]     Co-invented prior art U.S. Pat. Nos. 4,190,037 and 4,260,112 (1980-1) included a movable upper framework with attached water jets for cutting a fixed length parabolic curves required two machine slots for longitudinally spaced cutters mounted on the framework above the web, did not describe use of a lower oscillating frame to mount jet stream receivers (enegy dissipaters), and with a fixed length frame was limited to producing only one length of intersecting parabolic curves without means for adjustment.  
         [0005]     The instant invention covers a full range of parabolic apertures up to about 12 ft., and requires only one slot or space for two reversing programmable water jet cutters moving above and receivers moving below the moving web.  
         [0006]     In addition, the instant apparatus can produce segments having a plurality of parabolic curved surfaces, has low mass and inertia forces, is programmable for parabolic length and cutter movement using servo motors and digital software not available twenty five years ago.  
         [0007]     The instant invention includes two movable water jet cutters, each attached to a parallel spaced apart transversely oriented belt path, with belts driven by reversible servo motors following digital commands from a computer programmed for parabolic curves.  
         [0008]     The first path cutter generates an oscillating parabolic cut symmetrically about a longitudinal axis and crosses the axis coincident with both ends of the transversely cut segment.  
         [0009]     The second path cutter generates an oscillating mirror image cut symmetrically about the same longitudinal axis and crosses the axis at segment ends as it intersects the first parabolic cut. This interaction produces two opposing segments for each slit web, each segment with parabolic inside surfaces.  
         [0010]     Adding a second cutter to each belt drive replicates the intersecting parabolic cuts in a second adjacent slit web and produces a second pair of segments  
         [0011]     This invention also describes segments each having a plurality of parabolic cut surfaces per segment length and apparatus for making multiple segments from a plurality of parallel slit webs with water jet cutter drive means responsive to programmable commands based on parabolic apertures, focal points segment height and web slit width compatible with the corrugating machine width.  
         [0012]     For example, a 90″ wide corrugator will produce four segments from two 45″ slit webs. With an aperture of 7.5 ft and cut at web speed of 350 fpm, total machine output of 24 million segments annually is enough to make collectors with a total solar collector area of 150 million sq. ft.  
         [0013]     The instant apparatus includes an existing machine cutoff section, and successive sections for the dual parabolic cutters, a fixed plurality of jet cutters for longitudinal slits, transfer &amp; diverting, and alternating stacker sections.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a diagrammatic plan view of apparatus sections illustrating the rotary cutoff unit of the corrugating machine, a section with dual water jet cutters for reversing movement along parallel belt paths, a plurality of fixed jet cutters, a transfer section and two stacker sections with various cut components crosshatched for identification. Serial parabolic and slit cuts are shown.  
         [0015]      FIG. 2  is a diagrammatic plan view similar to  FIG. 1  illustrating selected sections with the parabolic cut describing a resultant pair of segments having a larger aperture.  
         [0016]      FIG. 3  is a diagrammatic plan view similar to  FIG. 1  illustrating selected sections with smaller parabolic cuts describing a segment with a plurality of parabolic surfaces on one edge. Selected segments are crosshatched.  
         [0017]      FIG. 4  is an enlarged schematic plan view of the parabolic cutting section illustrating two spaced apart jet cutters supported in slideable holders attached to belts driven by reversing programmable motors. Water jet stream receivers mounted directly below are obscured from view (See  FIGS. 5, 6 ).  
         [0018]      FIG. 5  is a schematic end elevation of the traversing cutters viewed along line  5 - 5  of  FIG. 4  illustrating programmable servo motor drives on opposite ends. The upper motor drives the jet nozzle and the lower motor drives the jet stream receiver directly below in synchronism with the nozzle.  
         [0019]      FIG. 6  is a schematic side elevation viewed from  6 - 6  of  FIG. 5  illustrating an upper jet cutter and lower receiver supported on cross rails and moveable on parallel adjacent paths. Servo motors for the second path are dashed for clarity.  
         [0020]      FIG. 7  is a schematic plan view of fixed jet cutters mounted above the moving web illustrating edge trim and intermediate longitudinal cuts that form and portions at the top ends of the parabolic shaped segments. Jet receiver tubes directly below the web are obscured from view (see  FIGS. 8, 9 )  
         [0021]      FIG. 8  is a schematic end elevation viewed in the direction of web travel along line  8 - 8  of  FIG. 7  illustrating the edge and intermediate cut positions.  
         [0022]      FIG. 9  is a schematic side elevation of the stationary jet cutters and receivers viewed from  9 - 9  of  FIG. 8 .  
         [0023]      FIG. 10  is an enlarged schematic plan view from  10 - 10  of  FIG. 11  illustrating the transfer and central trim diverting section, and two successive sections for alternate stacking operation and discharge in both side directions.  
         [0024]      FIG. 11  is a simplified side elevation schematic of the instant apparatus Illustrating the corrugating machine rotary cutoff section, water jet parabolic curve cutting section, jet trim cutter section, transfer and trim diverter section with vacuum bypass belts and two spaced stacker sections with programmable motor and drive system for movable platform from an upper loading position to a lower discharge position below the top of the stack support rails.  
         [0025]      FIG. 12  is a plan view schematic of a stacker section with overhead vacuum belts removed as viewed from  12 - 12  of  FIG. 11  and with the bottom segment removed illustrating the vertically movable platform slots and the spaced fixed rails to support a completed stack.(shown crosshatched for clarity). Transverse movable stack ejector arms are shown under complated stacks shown transferred to additional rails on both sides of each stacker.  
         [0026]      FIG. 13  is an enlarged side elevation schematic similar to  FIG. 11  viewed from  13 - 13  of  FIG. 12 , both stackers illustrating platform elevating and lowering means, upper and lower platform positions, and the overhead vacuum belt for transport of segments forward to the next stacker for alternating stack completion.  
         [0027]      FIG. 14  is a schematic end view from  14 - 14  of  FIG. 13  (platform drive omitted) illustrating the space between the top of the lowering platform and the rail supported elevation of the completed stack for insertion of stack removal arms and transfer to space adjacent the stacker on both sides. Upper center trim removal vacuum belt and segment vacuum belts are shown (also shown in  FIGS. 13, 18 )  
         [0028]      FIG. 15  is a diagrammatic plan view of a web for making four segments from two adjacent slit webs illustrating a pair of water jet cutters on each slit web to generate a pair of parabolic curves on each web which intersect a longitudinal axis of symmetry at segment ends. Jet cutters for trim slits shown.  
         [0029]      FIG. 16  is a simplified side elevation viewed along  16 - 16  of  FIG. 15  illustrating a spaced pair of cutters on both parallel transverse cutter paths.  
         [0030]      FIG. 17  is a diagrammatic plan view illustrating segment pairs each having three parabolic shaped surfaces being produced from a plurality of eight parallel webs slit from the full width web. Eight jet cutters on each transverse path cut sixteen oscillating parabolic curves to form sixteen opposing segments after intersecting at segment ends. Groups of four segments are stacked and ejected from each side. Each group of four segments requires two stackers in series for alternate stacking, Eight stackers for four segment groups are shown without space for platform elevating means.  
         [0031]      FIG. 18 . Is a simplified side elevation viewed from  18 - 18  of  FIG. 17  illustrating the downward position of stacker stop plates to bypass stackers when producing only corrugated paperboard segments for cartons.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]     In  FIG. 1 , sections  1 - 7  of the apparatus include the corrugating machine dryer  1 , and corrugating machine cutoff section  2  with adjustable length cutoff rolls  8  (lower roll under web W  1  not shown). Roll  8  is shown at the instant of cuttingweb W 1  transversely to form a segment length L  1 .  
         [0033]     Water jet cutting section  3  for parabolic cuts includes a first transversely movable jet cutter  10  for oscillating movement about axis of symmetry A-A′ along path  9 - 9 ′ to generate a parabolic cut line P above and below the axis.  
         [0034]     Section  3  includes a second transversely movable water jet cutter  12  for oscillating movement to generate a duplicate mirror image parabolic cut line P′.  
         [0035]     Cutters  10  and  12  are supported by holders  21 ,  21 ′ on spaced rails  22 ,  22 ′ (shown in  FIG. 4 ) and connected to belt systems driven by programmable servo motors with algorithm software for parabolic curves of different shapes and focus points.  
         [0036]     Cut lines P, P′ intersect at segment ends a distance L  1  apart. The solar aperture of egment  16  is equal to segment length L  1  minus the lands at each end of the segment after removal of trim pieces  15 ,  15 ′ created by water jet slitters  14 ,  14 ′ in section  4  as they cut through ends of cuts P, P′.  
         [0037]     Parabolic cut line P is spaced from the axis of symmetry A-A′ by plus values of the formula in one segment followed by minus values in a successive segment to define the oscillating shape above and below the axis. A similar mirror image parabolic cut line P′ is generated by the other jet cutter and the program for instantaneous values of the cutter position on the P′ curve is modified by the axial distance between cutters.  
         [0038]     In section  4  of  FIG. 1  center trim jet cutters  14 ,  14 ′ and edge cutters  13 ,  13  are mounted on a stationary cross support over the moving web.  
         [0039]     In  FIG. 1 , jet cutters in sections  3  and  4  are shown above the web. Jet stream receivers  31 , 33  for each cutter are shown below the web in  FIGS. 5, 6 .  
         [0040]     In  FIG. 1 , parabolic segment  16 , center scrap portion  17 , and an intermediate parabolic portion  18  adjacent the center scrap cut line are crosshatched for clarity of shape.  
         [0041]     In  FIG. 1 , transfer/diverter section  5  includes separate hinged plates for transfer of the center piece to a scrap belt and the two outside segments for transfer by two side vacuum belts  42 ′ to stacker  6 , and when the stack is completed, sliding advance to stacker  7 .  
         [0042]     In  FIG. 2 , web W  2  is cut into segment lengths L  2 . parabolic cuts P, P′ intersect at the rotary cutoff unit  2 ′ under roll  8 ′.  
         [0043]     In  FIG. 2 , jet cutter section  3  is the same as in  FIGS. 1, 2 . The values to generate the specific parabolic curves P, P′ are digitally entered into the software algorithm to position cutters  10 ,  12  on the programmed curve P, P′ which intersect on the axis of symmetry A-A′ at segment ends. The sum of axial distance from cutoff  8  to the first cutter  10 , space between cutters  10 ,  12  and the distance from  12  to the opposite segment end equals L  2  as shown.  
         [0044]     In  FIG. 3 , web W  3  is slit in half by stationary jet cutters  14 ′ in section  4 .  
         [0045]     In  FIG. 3  two spaced reversing jet cutters on path  9 - 9 ′ cut three curves P, and two spaced jet cutters on path  11 - 11 ′ cut  3  similar intersecting parabolic curves P′ in each of the juxtaposed half web segments  20  to produce segment pairs of length L  3  in each half web.  
         [0046]     The contour of the parabolas and the number per segment changes for different applications and determine segment length L  3 . For solar hot water collectors a plurality of three parabolic curves per segment is like U.S. Pat. No. 6, 892,724. Solar trough concentrating collectors for high temperatures have one parabola per segment as in  FIGS. 1 and 2   
         [0047]     For wider webs, mulltiple upper cutters and lower receivers are connected to belt drive systems along transverse paths  9  and  11 . Multiple slit webs, curves, and segments are shown in  FIG. 17 .  
         [0048]     In  FIG. 4 , components relating to cutter  10  on path  9 - 9  above the web cut curve P and include servo motor  23 , drive pulley  24 , upper belt portion  25 , lower belt  27 , and holder  21  supported by cross support  22 .  
         [0049]     Components for cutter  12  on path  11 - 11  above the web cut curve P′ and include servo motor  29 , drive pulley  24 ′, upper belt portion  25 ′, lower belt  27 ′, and holder  21 ; supported by cross support  22 ′.  
         [0050]     Upper belts  25 ,  25 ′ are cutaway to expose gear teeth of lower belts  27 ,  27 ′ for connection to holders  21 ,  21 ′ as at  28 ,  28 ′.  
         [0051]     Motor support frames  3 , motors  23 ,  29 , and other belt drive components extend beyond the outside edges of web W  1 . Oscillating movement of cutters reverses between nadirs of the opposing parabolic curves.  
         [0052]     In  FIG. 4 , the locations of receiver servo drive motors  30 ,  32  are shown dashed (other components obscured).Duplicate drives components (see  FIGS. 5, 6 ) are used below the web for moving jet stream receivers in unison with the cutters  10 ,  12 .  
         [0053]     In  FIG. 5 , portions of the top belt run  25 ,  25 ′ are cutaway as in  FIG. 4 . Bottom belt runs  27 ,  27 ′ are attached to a rear extension of holders  21 ,  21 ′  
         [0054]     In  FIG. 6 , corrugator cutoff rolls  8 ,  8 ′ cut web W to a selected length L. Butted segments are advanced by pressure belt  36  as they slide in butted relationship for web cutting by jet cutters  10 ,  12 , and longitudinal slitters  13 ,  14 . Subsequently speed up belts  42 ,  42 ′ create a gap between segments to provide space between segments and time for up or down movement of diverter plates as segments are directed toward stacker path  6  or stacker path  7 .  
         [0055]     In  FIG. 7 , cross support member  37  is attached to side frames of slitting section  4  to support edge slitters  13 , 13 ′ and center trim slitters  14 ,  14 ′.  
         [0056]     Slit cuts are made after the parabolic cuts P and P′ are completed upstream.  
         [0057]     In  FIG. 8 , cuts from slitters  14 ,  14  define center scrap piece  17  (shown in  FIG. 1 ) and create opposing end segments  15 , 15 ′ as top portions of parabolas are cut to create lands at segment ends (see  FIG. 1  exiting section  4 )  
         [0058]     In  FIG. 8 , trim cutters  13 , 13 ′ removes deckle or excess web  38 ,  38 ′ (shown In  FIG. 2 ) to define the bottom linear edge of segment  16 .  
         [0059]     In  FIG. 9 , jet cutters  13 ,  13 ′ are mounted on cross member  37 . Lower cross member  37 ′ supports jet stream receivers  39 .  
         [0060]     In  FIG. 10 , frame outline for sections  5 ,  6 ,  7  are shown dashed.  
         [0061]     Segments entering section  5  are butted and held against plate  40  by center speed up belt  42  and side belts  42 ′. Central plate  40  pivots about axis  41 - 41 ′, is inclined and directs center scrap for transfer beyond the end of the machine by suspended transfer under vacuum belt  43 .  
         [0062]     In  FIG. 10 , parabolic portions  18 ,  18 ′ adjacent center scrap piece  17  and the outer segments  16 ,  16 ′ advance along outer side paths over plates  44 ,  45  and under two speed up belts  42 ′ create a gap between successive units. The gap permits time for plates  44 ,  45  to pivot from one stacker path to the other, and portions  18 ,  16  are advanced as a unitary segment into engagement by side vacuum transfer belts  46 ,  46 ′.  
         [0063]     In  FIG. 10 , belts  46 ,  46 ′ terminate over first stacker  6  and advance by sliding forward to platform  51  in stacker  7 . For producing parabolic segments or standard corrugated segments, duplicate vacuum transfer belts  46 ,  46 ′ are added to stacker  7  to bypass all stackers and advance the uncut corrugated segment past the end of the last stacker for normal handling.  
         [0064]     After segment separation and transfer to vacuum belts and stackers, digital advance steps or position sensors (not shown) determine when a selected stack count is reached, other devices are activated to complete the stacking process including actuators for diverter plates  44 ,  45 , stops  48 ,  49 , vacuum for belts  46 ,  46 ′, elevator platform positions  51 ,  52 ′ or  51 ′, 52  and stack removal arms  63 ,  63 ′.  
         [0065]     In  FIG. 11 , stop plates  48  is in the up position when stacker  6  is in use and plate  49  is up to stop segments fdor stacker  7 . Both stops are in the down position when the machine runs only standard corrugated segments for Containers.  
         [0066]     In  FIG. 11 , stacker platform  51  in stacker  6  is shown solid at the uppermost elevation for receiving the first segment of a new stack. At this instant, stacker  7  is discharging a previously completed stack and is subsequently raised to position  52  by the time stacker  6  completes a stack.  
         [0067]     As segments are added to stacker  6 , platform  51  is lowered and successive segments are placed on top of the preceding segment until stack completion when the segment stream is transferred to stacker  7 .  
         [0068]     Platform  51  of  6  continues to lower until the stack rests on top of fixed rails  53 . Platform  51  continues to lower until reaching position  51 . With adjacent stacks on rails  53  and platform  51  at position  51 ′, stack removal arms  63 ,  63 ′ are inserted in space  64  from both sides, raised, and withdrawn to deliver stacks on both sides at positions  67 ,  67 ′.(shown in  FIG. 14 )  
         [0069]     The platform is moved upward from  51 ′ to position  51  while stacker  7  is stacking to deliver the next stack.  
         [0070]     Details of the platform are described in  FIG. 12 , and the platform elevating drive in  FIG. 13 .  
         [0071]     In  FIG. 12 , web portions  16 , 18  and  16 ′, 18 ′ (shown in  FIG. 1 ) are advanced together to platforms  51 ,  52 . Outer edge side guides  54  and inner side guides  54 ′ contain the components in rectangular unity as they advance to stops  48   49 .  
         [0072]     Segment end guides (not shown for clarity) extend downward a limited distance at the infeed end to allow component containment between stops  48 , end guides (not shown) and downward extending side guides  56 .  
         [0073]     In  FIG. 12 , platforms  51 ,  52  are duplicates.  
         [0074]     Platforms  51 ,  52  have spaced apertures  55  aligned above support rails  53 ,  53 ′ which support completed stacks when platforms  51 ,  52  are lowered below rails  53 ,  53 ′ (shown crosshatched).  
         [0075]     In  FIG. 12 , platforms have extended arms  57  contain threaded inserts  58  for cooperation with rotating threaded screw  60 .  
         [0076]     In  FIG. 13 , platforms are raised/lowered by screw  60  held in end bearings  59  as screw  60  is rotated by a motor and pulley drive belt system  61 .  
         [0077]     In  FIG. 13  vacuum belt  43  transports scrap piece  17 . Belts  46 ,  46 ′ each advance cut portions  16 ,  18  and  16 ′,  18 ′ above stacker  6 . Actuator  62  raises and lowers stop plate  48  with attached extension  48 ′ (see  FIG. 14 ).  
         [0078]     In  FIG. 14 , stack removal arms arms  63 ,  63 ′ inserted in space  64  move up to lift completed stacks C, C′ from support rails  53 ,  53 ′ for transfer to stack transfer positions  67 ,  67 ′.  
         [0079]     In  FIG. 15 , web W  4  is slit in half by jet slitter  19  of section  4  to form ]parallel webs, each with double parabolic cuts P, P′ to form segments stacks wiith  16  and parabolic portions  18 .  
         [0080]     Section  3  is as described above except another jet cutter assembly is added to each belt in path  9 - 9  and  11 - 11 .  
         [0081]     In  FIG. 15 , using two cutters (receivers not shown) on each path produces the intersecting parabolas in each half web and a total of four segment stacks that are alternately stacked as two groups in successive stackers. The second pair of stackers are moved downstream across blank spaces  68 ,  68 ′ to avoid stack discharge interference with the first pair.  
         [0082]     In  FIG. 16 , second jet cutters  10 ′,  12 ′ are added to the drive belt for  10 ,  12 . Belt drives  25 ′,  27 ′ show receivers  31 ,  31 ′ on path  9 - 9  and  33 ,  33 ′ on path  11 - 11 ′.  
         [0083]     In  FIG. 17 , a plurality of jet cutters  10 - 10   n  are attached along path  9 - 9  and  12 - 12   n  along path  11 - 11 . Multiple intersecting curves and segments are produced.  
         [0084]     In this instance, curves P, P′ intersect at parabolic length  69  and each segment length L  4  includes three parabolic repeats per segment. Since the intersections define three separate center strip pieces, these portions are rejected in a space below the web line before reaching the diverter/transfer section  5   
         [0085]     In  FIG. 17 , as remaining portions  70 - 70   n  without intermediate pieces are advanced rails  71 ,  71 ′ urge segment groups toward outside side guides  54  (center of  FIG. 12 ) thus creating gap  72  for insertion of stack removal arms  67 .  
         [0086]     In  FIG. 18 , two tandem arranged stackers  6 ,  7  include parallel vacuum transfer belts  46 ,  46 ′ to advance two groups of web portions  16 ,  18  forward. segment stops  48 ,  49  are selectively actuated when parabolic segments are being made.  
         [0087]     When stacker  6  is operating, vacuum to belts  46 ,  46 ′ is switched off and segment stop  48  is up. When stacker  7  is operating ,vacuum to  46 ,  46 ′ belts is on, stop  48  is down and stop  49  is up.  
         [0088]     For running only standard corrugated board without jet cuts all upper vacuum belts are operative and all stops are activated to the downward position.  
         [0089]     The present invention may be embodied in other specific forms without departing from the spirit or special attributes and it is therefore not restrictive, reference being made to the appended claims to indicate the scope of the invention.  
       REFERENCE NUMBERS  
       [0000]    
       
          W web: corrugated material  
           1  dryer section  
           2  cutoff section  
           3  parabola cutting section  
           4  linear sllitting section  
           5  diverter section  
           6  first stacker section  
           7  second stacker section  
           8  cutoff rolls  
           9 - 9 ; first cutting path  
           10  first water jet cutter  
           11 - 11  second cutting path  
           12  second water jet cutter  
          P first parabolic cut line from  10   
          P′ second para/cut line from  12   
          A-A′ axis of symmetry (longitudinal)  
           13 - 13  edge water jet slitters  14   
           14  intermediate w.j. slitters  
          L segment length  
           15  trim pieces at intersection  
           16  para. web portion  
           17  center scrap piece  
           18  parabolic segment  
           19  water jet web half slit  
           20  segment w/multiple parabolas  
           21  cutter and receiver holders  
           22  cross rails/supports  
           23  servo motor: cutter  10   
           24  drive pulley: cutter  10   
           25  drive belt: top-cutter  10   
           26  idler pulley  
           27  drive belt: lower (teeth show)  
           28  belt attachment to cutter holders  
           29  servo motor for cutter  12   
           30  servo motor for receiver  31   
           31  receiver for cutter  10   
           32  servo motor for receiver  33   
           33  receiver for cutter  12   
           34  fixed belt conn.to holder  35   
           35  holder for receiver under web  
           36  hold down bwlt: ex cutoff section on removal arms  
           37  cross support fot slitters  13 ,  14   
           38  deckle or trim excess web  
           39  fixed jet receivers for slitters  
           40  inclined plate: for scrap  
           41  hinge line for  40   
           42  speed up belt: center scrap  
           42 ′ speedup belts: side webs  
           43  upper scrap vacuum belt  
           44  first plate: left web portions  
           45  second plate: right. web” 
           46  first vacuum xfer belt-L.H.  
           46 ′ 2 nd  vacuum xfer belt-R.H.  
           47  air cyl fo diverter plate  
           48  stop plate: stacker  6   
           49  stop plate: stacker  7   
           48 ′ Extension for pl.  48   
           50  level posit: parabolic or corr.  
           51  #  6  platform-upper posit  
           51 ′ #  6  platform-lower” 
           52  #  7  platform-upper posit  
           52 ′ #  7  platform-lowerposit  
           53  stack support rails  
           54  segment side guides  
           55  platform apertures  
           56  vertical segment side guides  
           57  platform extension arms  
           58  threaded inserts in arms  57   
           59  bearings for screw=both ends  
           60  platform elevating drive  
           61  servo motor for drive  60   
           62  actuator for stop plates  
           63  stack removal arms  
           64  space fpr arms  63   
           65  external stack support rails  
          C completed stack  
           66  vertical lip on arm  63   
           67  stack tramsfer positions  
           68  floor space for stack removal  
           69  parabolic aperture length  
           70  segments with 3 parabolas  
           71  diverter rails for groups  
           72  space between stacks for lips on removal arms