CA2126572A1 - High capacity sheet feeders for high volume printers - Google Patents

Abstract

2126572 9411288 PCTABS00032 A high speed sheet feeder (21) for directing sheets to a host utilization device having a stack feed elevator platform accessed by a drawer provides a feed ramp (29) for supporting a stack of sheets. Sheets in the stack are deshingled by a feeder singulator (24) and driven, typically, downwardly to a feed tray (26) extending remote from the singulator. The feed tray (26) receives sheets in a space that enables formation of a second smaller stack of sheets. The tray (26) further includes an opening adjacent the second stack that enables sheets to be slid from the top of the second stack. The tray (26) is positioned and constructed so that it can enter and be removed from a port in the drawer of the utilization device. The feed tray's positioning relative to the port allows sheets in the second stack to be placed adjacent a utilization device singulator (143) in the drawer so that sheets can be removed by the utilization device singulator (143) for processing thereby. In utilization devices having two drawers positioned one atop the other, the tray can be constructed so that the drawer not interfaced with the tray can be accessed for loading without removing the tray from the other drawer.

Description

WO94~11288 PCT/US~3/1~9~9 212657~

HIGH ~APACITY ~HEET FEEDERS FO~ HIGH VOL ~ PRI~TE~S
Related_~pplications This application is a continuation-in-part of co-pending U.S. Paten~ Application Serial No. 07/775,200 filed October 9, l99l.
:
This invention relates to extremely high capacity sheet feeders, for supplying a block of as many as thirty reams of paper~sheets, automatically fed to the infeed mechanism of such high volume printers as the Xerox~ printer model 9500, ~700, 4090, photocopiers or other sheet paper using "host" machines.
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: Related~Art .
Thes~ high ~olume copiers or cut sheQt printers are -each provided~with paper supply feed mechanisms, ~;consisting of an~elevator platform adapted for vertical ~e-~evatio~. ~A variable c~apacity stack of~paper sheets, generally 500 to ~,000 sheets, is placed ~n th~
~platform~, which is~elevated on command until the uppermost sheet contacts the printer's feed mechanism.
Th~ ascent of ~the paper s~ack is stopped by ~he printer's feed~ mechanism limit switch. : : ::
~ As the uppermos~ paper shee~s are fed~into the~
printe~, the limit switch is deactivated, ~hus ràising the~piatform~and the remaining stack of~paper~ sheets m~il the: cycle is repeated. : : : :
When this load o~ sheets has been fed through the copier or printer, ~a "reload" time o between two and ~Ive minutes may be r-guired to place up to e}ght more :: .

W094/112~8 PCT/~3/10909 ~6~ ~ 2 - ~.

reams of paper sheets on the tray in succession, with proper edge alignment for feed registration. The loading opera~ion, therefore, consumes between lO and 25% of the printer's total operatin~ time.
.' Brief Summary of the Invention The slanting loading ramp and feed mechanism of this sheet feeder invention permits as many as thirty reams or l5,000 sheets of paper to be loaded and aligned as an :~
elongated block or feed stock column, at the user's ~
con~enience, without interfering ~ith the printer's ~:
normal high volume printing operations. A very~brief .
interruption p~rmi~s ~he loading ramp of the present invention to advance its total feed stock column into feeding position, and the counterbalanced infeed tray of the feeder is already in the feeding position, ready to continue resupplyîng the print~r.
When access~to~the infeed tray of the high Yolume printPr is desired~for no~mal operatiQn, adjustments, inspection or maintenance,~the shee~ feeder of the ~:
present 1nvention can be éntirely unlatched and r~olled away along an:underlying:track, providing ample access to all sides of the~::host machlne.
These~high volum~ copiers~ and printers take their infeed sheets from the~top of~the shee~ stack on the ele~ator ~ray. As long as the leveI and hen~e the position of the top of the paper sta k does not vary by more than approximat~ly f:ive to eight sheets, the eleva.~or tray wil~ not received the as~end signal from ~he printer's~ee~ mechanism limit switch. Therefore, once the paper stack ~ormally ~laced on the el vator tray by ~he op~rator is replaced~by th~ similar stack of -paper re~sting on the counterbalanced infsed tray of the ;~
:: high capacity eeder, ~he prin~er's feedinq mechanism is - ,.

WOg4~ 88 ~ 1 2 6 S 7 2 P~T/US~3/1~909 unable to distinguish between ~he two. The loading ramp devices of the present invention feed fresh shingled ~;~
sheets ~o the bottom of the stack on the feeder's counterbalanced infeed tray, employing a unique singulating and/or shingling feed mechanism which has the additional advantage of avoiding snagging of any perorations along the edges or body ~f the sheets being delivered to the underside of the stack on the coun~erb~lanced infeed tray of the high capacity feeder. The l~vel of the s~ack is maintained through the us~ of a leveI sens ing bar which controls the resupply on demand wh~never three to f ive sheets are needed.
It is a principal object of the present invention to pro~ride high capacity sheet feed~s ~or highly efficient supply o paper sheets to high ~rolume printers, copying machines, etc., without the need of com~mnicating with the host ma~hine, minimizing or liminating printer downtime or infeed sheet loading.
~ Another object of the invention is to provide such h~igh capacity sheet :f~eders ~employing a :diagonal loading ramp capabl~ of: carrying as many as thirty reams of , paper shee~s.
Still another obj~ct of the inYention is to provide such sheet:feeding de~ices which are capable of s~i:ngulating:and/or shingling~sheets fed from the device : to the underside of an inf~eed sheet stack on the;: :
~eeder's counterbalanced infeed tray platform, and : presep~,ing the platform and stack to a high volume : prin~er or similar machine.
A further object of the invention is to sinqulate and/or shingle the paper sheets delivered to the infeed : platform in;~an overlapping feed stream sufficiently fanned ~o elimina~e lntersheet "fibre-lock" friction W094/112XX PC~/US~3/10909 ~lZ657æ

force in order to insure that the infeed paper sheet stack is in optimum condition for single sheet feeding through the high volume printer or other machine.
Another object of the invention is~to provide automa~ic feed advance of the entire multiream column of sheets to be delivered to the feeder's counterbalanced infeed tray platform, thus providing automa~ic and continuous resupply of singulated shingl~d sh~ets to th~
host machi~e's ~eding mechanism.
Still another object of the invention is to pro~ide high capacity sheet feed loaders o this character with fail safe and foolproof limit switches, avoiding the possibility of jamming or interruption of normal feed operations, and of damage to the host machine.
Yet another obj~ct of this in~ention is to provide a system for feeding front and drawer loaded printers an~
copiers such as the Xerox~ rnodel 4090, IBM modeIs 3827/2~ and Kodak model 1392 printers.
O~her objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the features of construction, combi~a~ion of elements, and arra~gemen~
of par~s which~will be exemplified in the: construction hereinafter set forth, and the scope of the in~ention will be indicated in the c1aims.
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The Drawinqs For a fuller understanding of the nature and ob3ects ! ! of th~ invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which:
Fig. 1 is a perspective diagrammatic view of the high capaci~y~sheet::~feeder of the present:inve~tion shown in operating position with its counterbalanced .

W094/1128~ PCT/U~3/10~9 2126~72 infeed tray under the feed mechanism of a high volume printer, such as the Xerox model 9500, which is shown in dot-dash lines at the left side of the figure;
Fig. 2 is a front elevation view of the high capacity sheet ~eeder of the present invention, partially broken away to shows its internal construction;
Fig. 3 is a fragmentary enlarged fron~ elevation view of the cooperating components of the fQed mechanism of the de~ice;
Fig. 4 is a fxagmentary cross-sectional end elevation view of the same feed mechanism components;
Fig. 5 is a::fragmentary cross-sectional diagrammatic end view of the track latch mechanism securing the:
feeder in its operating position and capable:of releasing it for rollaway s~ervicing, maintenance, or normal operation of the hast machine, without the high capacity feeder;
: Fi~. 6 is a perspective view of the singulating shingling:mechanism of the device for delivering fresh sheets to the under~side of~the sheet stack~on ~he aounterbalan~ed infeed tr:ay platform~o:~ the feeder; :
Fig. 7 i~s a~front::elevatlon view of the same slngulating shingling~mechan:ism;~: :
Fi~. ~ is~a fragmentary great:ly~enlarge~ rear:
ele~ation YieW~of the s;ame singula~îng shlngling mechanism;
Fig. 9 is ~a fragmentary cross-sectiona~fr~ont ele~ation view of the:same mechanism receiving :
indiv-idual sh~ets delivérad by the high aapaclty sheet feeder, showing th~ singulating operation of the device;
~ Figs.~:lOA and~10~ are fra~mentary cross-se~t:ional ~iews tak~n~;along the planes~lOA-lOA a~d~lOB-lOB in Fig. 9, both~substantially~perpendicular to ~he advancing sheets as they are singulated by the device;

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WO 94~11288 PCI`/US!~3~10~09 ;

Figs. 11, 1~ and 13 are fragmentary schematic cross-sectional front elevation views of the feeder belt drive mechanism showing the operation of two dif~erent limit swi~ches designed to actuate the drive and to ~:~
deactivate the feed advance before oYerfeeding has occurred; . ~~i ~:
Fig. 14 is a fragmentary front èlevation view of the deli~ery portion of the slngulating shingling:mechanism delivering fresh shee~s to the undersid~ of the sheet stack on the count~rbalanced infeed tray platform of the feeder; , -Fig. 15 is a corresponding fragmen~ary front elevation view of the same mechanism after a suitable :~
stack of sheets has been fed to the underside of the same sheet stac~
Fi~s.~16: and 17 are enlarged fragmentary rear ~levation views:showing:the:full stac~ ~ar limit switch :~p~eration,~deactivating the:delivery of inf~ed~sheets until the infeed;~stack has ~een~educed by normal printer operation;
F:ig. 18 is~a perspecti~e ~iew of a~sheet feeder according to an alternative embodiment :o:f this invention nterfaced~with~a drawer-loaded ~rinter,~
Fig. 19~is:a partially ~xploded perspective ~iew of -~
the exterior of:the:printer of Fig. l~ adapted;~to ~ :~
inter:face with the sheet:feeder according to this : :
~embodlment;
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: Fig. 20 is a f:ro~t perspective view of the sheet feeder. according~to~this~embodiment; `~ :
Fig . ~21 is a more detailed fra~nentary exploded view of:the modification to the drawer:fronts of :the prin~er:
accor~ding to thls embodlment~
; Fig.~21A is an exposed sid2 view of the printer ~:
::drawers according to this:embodiment; :~

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.... , .. ,: ... ..... ............... . ... ..................... . .... . ....... ... .. . .. .

WO94/11288 PCI/US~3/10909 Fig. 21B is a more detailed perspective view of a feed mechanism- interlock according to this embodiment;
Fig. 22 is a more detailed exploded view of a modific:ation to the drawer feed elevator platform for the prin~er according to this embodiment;
Fig. 23 is a more detailed fragmen~ary perspective view of the sheet feeder feed tray according to this embodiment;
Fig. ~3A is an exposed, partially exploded perspecti~re view of the feed tray of Fig. 23;
Fig. ~4 is a cross-sectional front view of the printer drawer interior havi~g the feed tray positioned therein according to this embodiment;
Fig. 25 is an exploded perspective view of a modification to a drawer loaded pri~ter accordin~ to yet another alternati~e embodiment of this invention; :
Fig. 26 is a perspecti~e view of an unmodiied feed :drawer for ~he printex ac~ording to this embodiment;
Fig. 27 i5 ~a fragmentary perspective view of a modified feed draw~r for lnteracing;with the sheet feeder according to this embodimen~
Fi~. 28 is a fr:a~mentary perspective view of:the feed drawer and feed tray~accordlng to this embodiment d~tailing:the inter~acing entry path for the tray into the dr awer, Fig. 29 is a fragmentary perspective view of the modified feed d~awer according to this embodiment : :
d~tailing the sheet feeder interlock;
F~,. 30 i~ an exposed perspective view of an unmodi~ied drawer feed ele~ator platform mechanism accor~ing to this embod:iment, ~ ~
Fig. 31 is an exposed perspective view of a dr.awer feed platform of a modified feed drawer elevator platform adapted to recei~e the feed tray according to this embodiment;
.

WO~4/11~88 PCT/U~93/10~09 Fig. 32 is an exposed perspective side view of the modified drawer feed elevator plat~orm detailing the path o entry of ~he feed tray thereinto according to this embodime~t;
Fig. 33 is a more detailed f.ragmentary perspective ::
view of the feed tray according to this embodiment; and Fig. 34 is a cross-sectional front view of the modified drawer feed platform ac ordi~g to this -~
invention having the f.eed tray posi~ioned therein.

Detailed Description of the Preferred Embodim nts The high capacity sheet feeder 21 shown in ~he figures comprises a base frame 22 of eIongated rectangular conflguration, haviny at one Pnd a vertical support column 23 underlying and:supporting a singulating shingling mechanism 24, which has a counterbalanced sheet infeed tray pl~atform~26 ;~
cantilev~red ou:~ward~from t~he:left end;:~of the eeder 21 :;
shown in Fig. 1 to engage t~he feed mechanism 143 of a high:volume host~machine 27 such~as ~he Xexox Model 9500; :~
or ~odel 9700 printer. Sloping diagonally upward from a short:end~column~28~at~the opposite "~l:oading~'' end of :; ~;~
base~r~me:22 is~a~slanting:loading feed ramp 2g on: :~
which~s many as thirty reams or l5,000:~ heets of paper ``:
to be fed to~printer:~2~ can be stacked~edgewise in an~
:elongated resupply feed block:~3l.: Column 28 houses ~ :
~resupply feed moto~ M and the resupply drive and tr:ansmission asse~ ly.
por~ column~23, base frame 22 and end panel 28 :form with loadlng eed ramp 29 a sturdy and stable tEi~anqular:structure, easily:capabl;e of supporting this :entire~load:of:thirty reams of paper,~ extending:~on t~e slant1ng~ramp 29~from its low loading ~nd up to its high ~feed end, or from right to left as viewed in Figs. l and ~ ::

WO ~4/1 1288 2 1 ~ 6 5 7 2 PCI/US93/1091)9

2. Sheet ~eeder 21 is supported on rollers 32 engaging a pair o~ tracks 33 anchored f irmly in position on the supporting floor 34 by adhesive 36, which may be double sided adhesive tape, for example, shown in Fig. 5, applied directly ~o carpet, vinyl or o~her flooring.
As shown in Fig . 5, . the front track 33 is pro~rided with a lock aperture 37 in which a vertically withdrawable lo~king bolt 38 is normally engaged, and held in position by a ~iasing spring 39 urging the bolt 38 downwardly into the lock apertuxe 37. The mecharlism illustrated in Fig. 5 allows the locking bolt 38 to be withdra~i whene~rer an unlocking bar 41 is depressed downward to the dot-dash lin~ position 41A sho~n in Fig. 5.
Unlocking bar 41, best seen in Figs. 1 and 2, :
extends lengthwise a~ross the front of column 23 at the user's waist height between two pivot arms 42. As shown in Fig. 5, arms 42 are pivoted in the upper front portion of column 23 on a pivot pin 43, and are thus movable between the solid line position 42 and the :~
dot-dash line position 42A shown in Fig~ 5.
`:
In the position 42A,~:pivot arms 42 raise an anchor bloc~ 44 mounted at the rear end of arms 42 and clamped by a set screw~to the upper end of an actuator rod 46, whose lower end is anchored to the upper end of locking bolt 38, all as shown ln Fig. 5. Downward movement of unlo~king bar ;41 thus raises ~actuator rod 46: and bolt :
38, releasing a microswitch 45 to switch the eeder ' s power ~off t withdrawin~ ~he bolt from~ lock aperture 37 and freeing the ent:ire sheet feeder 21 for rolling :
movemen~ on:rolI~rs 32 along track 33 i~ a direction :
away from printer~27 to the right in Fig. 1. This:
rolling movement withdraw~ the ~singulator shi~gling mechanism 24 and the counterbalanced sheet infeed W094/l1~8X PCT/US?3/1oso~ .

212 65 72 - lo - ~

platform 26 from printer 27, and allows free access to all sides of printer 27 for normal operation, inspection, maintenance, repairs or the li~e.
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Feed Ra~mp The diagonally slanting feed ra~p 29 is best seen in the broken away side elevation view of Fig. 2, where an elongated block of multiple reams of paper sheets is shown position~d on the diagonal ramp 29. A pusher plate 47 is shown at the right hand side of Fig. 2 and is L-shaped in co~figuration, with its tall~st arm 48 ::
leani~g agai~st the lower end of sheet feed block 31 in ~:~
the manner of a bookend while its shorter arm 49 extends along a~d rests upon ramp 29. A fragmentary enlarged view of pusher:plate 47 is also shown in:Fig. 3 and a ~-perspec~ive Yiew of:~he pusher p~ate also appears in Fig. 1.
As shown in the figures, a dri~e:carriage 51 is mounted for movement with mo5t of it~s structure po~itioned directly beneath loading~ramp 29 for sliding engagement with:a guide rod 52:suspended along the lower edge of a depend~ing web plate~55 mounted on the underside of ramp 29. As shown in the end elevation view of Fig. 4:, carriage 51 incorporates a base 53 und~rlying !a ~sleeve block 54:incorporating a ~
long1tudi~a1 cylindrical sleeve passage 56 sl idingly ~ :
engaging the:guide rod 52. Sleeve~:block 54 is shown bolt~d to base 53 in Fig. 4, and is 1nd1cat~d in solid :
and .d.!ash lines in:Fig. 3. Beside longitudinal guid~ rod ~`:
52 is a longitudinal feed screw S7 also pos:itioned under , .
ramp 29 directly above base 53 of driva~carriage 51. :~
The drive carriage is provided with a threaded feed ~ut 58 bolted to base 53, w1th threads engaging the mating threads of feed scr:ew 57.
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W094/112~ 2 1 2 6 ~ 7 2 PCT/US93/10909 The guide rod 52 and its supporting web 55 are suspended cen~rally from the underside of a guide rail channel 59 anchored to the underside of feed ramp 29 and having elongated rectangular downwardly depending rails 61 along its entire length under ramp 29. The lower edges of rails 61 are spaced above the normal position of base 53, as indicated in Fiy. 4. A small portion of the nearer rail 61 is sho~n at the right and left sides of Fig~ 3, and the lower edge of the r~mote opposite rail 61 is shown just beneath feed screw 57 in Fig. 3.
A pair of pivoted hooked side pla~es 62 are pivotally mounted on base 53 by pivots 63. As indicated in Figs. 3 and 4, side plates 62 are free to pivot between tws:) workirlg positions, a drive position illustrated in solid lines in Fig. 3, in which upper drive hooks 64 are in position for engagement with the pusher plate 47, and a retracted position 62A shown in dot-dash lines in Fig. 3, in which the drive hooks 64 are lowered to a position 64A again shown in dot-da~h lin~s in Fig. 3. In this retracted position, the drive hooks 64 are beneath pusher plate 47, l~ving th~ en~ire carriage 51 and:its associated drive hooks 64 free for re~urn movemen~ from the upper end of ramp 29, beneath the multiple she~t feed block 31 on the~ ramp, to a 1ow~r position near thP lower end of ramp 29, where they may again be engaged with the n xt pusher plate, ready to ~:
drive a new multiple sheet feed block 31 up ramp 29 to follow ~he pre~ious fe~d block in~o feeding position.
Resilient te~sion coîl springs 66 have their ends secux~d i~ suitable anchor fittings 70 ln the forward end 67 of ~he carriage base S3, and their r~ar ends suitably anchored in side plates 62 beneath pivot 63 at the r~ar end of the side plate, by anchor fittings 68 formed in this lower corner of each pivoted hooked side ..:
''''' W094/11~88 PCT~S~3/10909 plate 62. Coil springs 66, being installed under tension, resiliently urge side plates 62 toward their solid line position shown in Fig. 3 with their drive hoo~s 64 engaging the pusher plate 47. However, when drive screw 57 is rotated in its reverse direction, causing feed nut 58 and the enti~e carriage 51 connected thereto to traverse back down the sloping structure toward its lower end, hooks 64 are urged downwardly under the feed block 31 of multiple paper sheets, in~o the dot-dash line position 62A shown in Fig. 3 for the passage back down ramp 29 under the entire feed block 31, with the coil springs 66 being correspondingly stretched during this downward traverse of the carriage 51.
In order to adjust carriage 51 and its side plates 62 for minimum friction on guide rod 52 and feed screw 57, a pair of adjustable rail guides 69 are mounted in the base 53, projecting upward respectively against the dependiny lower edges of rails 61. The structure of each rail guide 69 lS shown in the fragmentary cross-sectional central portion of Fig. 3, where the rail guide is shown to have a flat upper~ surfa~e engaging the lower ed~e of rail 61. Each rail guide 69 has a central bore 73i loosely accommodating an adjustment screw 71 with a stainless steel ball 72 at its upper end centering rail g~lde 69 directly alonq the axis of the adjustment screw 71 in the conica:1 blind end of the central bore 73 of the ra11 guide 69. Adjustment s~rew,,l 71 iS threaded into basé S3, as indicated in Fig. 3 and the central bore 73 of guide 69 is oversized and not engaged with the threads of adjustment screw 71.
Formed in the upper inside corners of the channel shaped guide rail 59 are flanges 74, depending from the flat central web portion of the guide rail 59, with ~, WO 94/11288 212 6 5 7 ~ PCI`/US~3/10909 their edges in close juxtaposition to the edges o inwardly extendiny flanges 76, protruding inward from the upper portion of each rail 61 and farming enlarged recesses 77, usPful as wiring and guide tunnels, accessible through inwardly facing dia~onal slots 78 between flanges 74 and ~6, through which wiring cables and the like may be inserted during assembly.
Adjustmen~ of the adjustment screws 71 on each side of base 53 to raise the rail guides 69 into sliding -~
contact with the lower edges of the rail 61 assures smooth guiding alignment of carriage 51 along the guide rod 52 and eed screw 57 while minimizing any :~
misalignment forces applied by the hooked side plates 62 engaging pusher plate 47, which might tend to cause bindi~g or excessive friction ~etween the carriag~ 51 and the guide~rod S2 or the feed screw 57. It should b~
noted that the base 53 of drive carri~ge 51 is provided at its forward end wlth a stop pin 79 protruding outwardly from t~.e lateral edg~ of base 53 into interfering alignment with a stop ledge 81 formed at the forward lower~corner of side plate 62, facing in the direction of pivot pin 63 and positioning the hook 64 at the correct height for engaging the re~r~ flange edge of shorter arm 49 of pusher plate 47, as indicated at the upper portion of Fig. 3. The driven edge 82 of this shorter arm flange 49 of pusher plate 47 fits into a mating hook slot 83 ormed in the hook 64 of side plate 6~. Slot 83 has a beveled lower portal lip 84 for ::
slidin~ entry~of the:dri~en edge 82 into the slot 83.
The upper lip 86:of hook slot 83:extends forward o~er ~he driven edge 82 by an appreciable distance, thereby st~bi1izing pusher plate 47 in its driving engageme~t with side plate 62 and pre~enting the pusher plate from rocking or leaning backward under the load provided by WO 94/11288 P(~/US93/10909 '~265~2 - 14-the sheet feed block 31, whosP considerable weight would otherwise tend to tilt pusher plate 47 backward over side plate Paper Sheet Block Loading O~eration As indicat~d in Fig . 1, pusher plate 47 supplies transla~ion force tending to move the entire sheet feed ~`
blc~cl~ 31 up ramp along the ramp 29 from the loading end to the f~ed end of the ramp closely adjacent to the singulating feed assembly 105 and cou~terbalan~ed infeed tray 2~. Th~ delivery, singulation and shingling of the individual sheets at the feed end of feed~block 31 will be d~scri}~ed in detail here~nafter. As sheets are r~moved from the feed end of the ~e~d block, automatic sensors pr~duce advancing movement of feed screw 57, revolve~ by a feed screw drive~motor M whi~h is preferably pos~itioned in c~lumn:28 at the lower :end of the;~feed screw 57~ as indicated~schematically~in Flg.~2.
Advancing ~eed rot:ation:of the~feed screw 57 causes the pusher plate 47 to move upward alonq diagonal ramp ~29, as pre~iously described~. When the pusher plate 47 reaches its~uppermost position 4~A shown at the left side of Fig. 2,:all the rest of ramp 29~provides ample room for~reloading of a new:~elongated mu~ltiple ream~
co1umn o ;~heets forming the:~eed b:lock;~31, align~d again~st a:rear~paper~gu1~de 50~as indicated in Fig.~2, with~a new~pushe~pl~te 47 belng;mounted at~the lower::
righ~ hand end, in position to feed this new block 31 up ramp .sJh~never desired.

~: : : : : : : ::
: : ~ Fail Safe Feed Screw~peration ~ As the:last sheets are fed~from the~p~evious eed , ~lock~to the~:le~t of pusher plate~position 47A, drive~
p1ates~62:have~reached their upper terminal position:.

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W094/11~8~ 2 1 2 ~ 5 7 2 PC~/U~93/10909 Two sensor switches 87 and 88 are illustrated directly below the pusher plate 47A in the terminal position in Fig. 2, the right hand one of these, switch 87, being a deceleration sensor switch assuring ~hat the feed screw rotation will be reduce~ to a very slow forward feed as soon as deceleration sensor 87 is actuated by the arrival of drive carriage 51 in contact with its sensor arm, and simultaneously a flashing light is initiated, warning of impending runout of the paper sheet supply.
The secoIld or left one of these switch~s is a stop sensor 88, and ~he arrival of the drive carriage 51 at the position where it actuates the sensor arm of stop sensor 88 opens the switch therein and cuts of f f orward feed rotation of feed screw 57, also changing the flashing light to a conti~uous light indicating the actual out o paper condition. ~:
Therea~ter, upon colrunand, the feed :screw may be rotated in its re~erse dire~tion causing the drive carriage 51 to move down the slanting feed ~crew, disengaging hooks 64 from the pusher plat~ at its terminal position 47A. The pusher plate 47A may then be removed and continuing re~erse rotation of feed screw 57 merely depress hooks 64 under block 31, ~s indicated in position 62~ sho~n in solid li~es in the central portion of Fig. 2 and in dot-dash lines in Fig. 3, with hooks 64 depressed beneath the upper surf ace of ramp 29.
At the right hand end of Fig . 2, the new pusher plate 47 is shown standing on ramp 29, with its shorter arm 4-~ xtending underneath a stop bar or s~op post 89, and its taller arm 48 standing up ramp from stop pos~ 89 and in abut~ting engagement therewith. The pusher plate 47 may be plac0d in this position like a sheet metal bookend while multi~le reams of paper are placed edgewi~e on ramp 29 leaning against pusher plate 47.

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WO 94/1 1 28X PCI`/US93tl 0909 21265~2 ', Su~cessive reams are stacked, progressively arrayed in the up ramp direction, until the entire block 31 is loaded on ramp 29, as indicated in Fig. 2. While the pxevious singulated and shi~gled sheets from ~he previous feed block 31 are-being delivered to the counterbalan~ed infeed ~ray, ~his retracting repositioning of the drive carriage 51 can be initiated and often completed in a very shor~ period of time.
When the dri~e carriage 5~ reaches t~e lowermos~
position i~dicated at the right hand end of Fig. 2, two further limit switches are actuated, the deceleration sensor 91 and stop sensor 92, performing functions ~
similar to sensors 87 ~nd 88 at the upper end of ramp 29. ~;
In its lowermost stopped position, shown at the right hand side of Fig. 2, t:he hooks 64 have cleared the underside of block 31 and pllsher plate 47i and the . ~
springs 66 have raised s~ide : :plates 62 above the level of ~:
ramp 29 in the down ramp position beyond pu~her plate 47 as illus~rated in Fig. 2.
Actuation of motor M, located beneath the lower end of ramp 2~ 1n the short end column 28, to produce ~;
resupply ~eed advance rotation of feed screw~57 advances th~ drive carriage 51 with side plates 62 deploying hooks 64 into e~ga~ement with flange 49 of pusher plate 47.~ As a result,:pusher plate 47 is driven slowly up :
ramp 29 ~t~ the uppermost feed~end of feed block 31: :
.. .
reaches the position where the f irst sheets of the feed block are ready~ for singulation and shingling iIl the :
remai-~ifig subasserrblies of this invention. :
At the lower or loading end :of :the high capaci~y :: :
sh~et feeder:21 show~ ln Fig. 2, the feed screw 57 is showr~ supported in a bearing 93 mounted on an end wall 94 of the overall assembly, :u~standing from a lightweight base panel 96 underlying the feed screw 57 and suide rod 52 along the entire path of travel of drive carriage 51 from the lower loading edge of ramp 29 shown in Fig, 2 to the upper feed end of the ramp at the upper le~t hand end of Fig. 2. The bearing 93 mounted on end wall 94 is mounted in a sacrificial bearing mount, a lightweight sheet metal centering cup, designed to hold feed scr~w 57 in its desired positio~ during all normal operations with normal feed loads. If any unusual fri~t~on or jamming interference of parts produces endwise translation of feed screw 57/ this sa~rificial cup bearing mount for bearing 93 ~utomatically inverts and breaks loose~from end wall 94, avoiding any damage to the more:~alua~le ma~hi~ed parts such as the feed screw, the drive carriage 51 and its ~:
related subassemblles, the side plates, the pusher pla~e ;
47 or a~y of the sensors 87, 88, 9l a~d:92. Any such unusual: friction or interference occurring:at the upper end o the ~ravel of carriage 51 along~ eed screw 57 .
~e:ar the upper feed end of ramp 29 will produce the same ~i result~ with breakaway protection for the valuable ~
component parts:of~the device. When repalrs or ~:
: adjustments are completed, a new:sacriicial beari~g :~ moun~:se¢uring bearing 93 in end wall 94 allows the entire assembly to be reasse~led and restored to ;:operation readily. : .
.
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Feed Mechanism ~or~ lndividual Sheets The singulator shingling mechanism 24,: the 1' , ' ! ' . : : ~
counte:r~a1anc~d infeed tray 26 and the:;~sheet stream : feeder~97 are~shown in the fragmentary:perspecti~e view of:Fig. 6, and they are also seen in the upper centxal portion of Fig. 1 between the sheet feed block 31 and :the~pr:inter 27. I~ additio~, the side view of Fig. 7 : shows the side~ele~ation of these subassemblies in their cooperating relationship.

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WO~4/11~8X ` P~T/US93/10909 2 ~2 6S7 2 - 18 -Sinqulatinq Feed Assembly As the frontmost sheet 104 of the feed block 31 arrives at the upper end of r~mp 29, it is thus delivered into abutting contact with a singulating feed assembly 105 shown in Fig. 6 and in more detail in Figs. 7, 8, 9 and 11-13; This feed asse~bly dri~es the singulating belts 102:to strip each frontmost shee~ 10~ -in turn from feed block 31 and drive it downward into th~ sheet stream feeder 97. In addition, the singulating feed assembly 105 is articulated, and proYided with two limit swi~ches gov~rning the feed screw opera~ion to advance the feed block 31 into its :;
feed position, and alternatively to cut off fee~ a~d shut down the entire device as an emergency stop condition if the feed block 31 is moved too close to the singulating feed assembly creating a risk of jam~ing.
Removal of a few sheets from the frontmost portion of feed b1ock 31 then reinitiat:es normal fe~d operation.
The block of sheets 31 deli~ered up ramp 29 to the singulating feed assembly 105 arrives on a deli~ery deck~
98 ha~ing a d~wnward sla~ting deck ramp 99 ending at a terminal deck edge 101 closely adjacent:to a pair of round polymeric s:ingulating belts 102. Smooth rounded notches~03 are formed in deck ed~e 101 to ac~ommo~ate singulating belts 102,~and the deck 98 is adjustable~
o~er a short range of motion toward and away~from~belts 102 to vary the~space between the singulat~ing b~lts 102 and the depth of notches~ 103. Slight intrusio~ of:
singu~a~ing belts 102 into the notches 103 has the eect of causing an arching or bu kling shape of the frontmos~ paper sheet 104 in direc~ contac~ with the singulatlng belts 102, as shown in Fig. lOA and this ~rontmost sheet 104~is thus slightly arched, with a c~ntral arched portion spaced very slightly away from .

WO94/112~X 2 1 2 6 ~ 7 2 PCT/US93/10909 :, deck edge 101, and also with outer arched por~ions spaced sligh~ly away from deck edge 101, with the singulating belts 102 depressing two tractive portions of frontmost sheet 104 into the mouth of the respective notches 103 in ~he deck ramp 99. .:~
This arching or buckling configuration of frontmost sheet 104 assures that any fibre~lock adhesion between frontmost shee~ 104 and the following flat sheets directly behind it will be broken by the presence of air molecules be~ween these shee~s,~assuring the effective singulation of each frontmost sheet in turn as it is contacted by~singulating belts 102 and driven downward toward feed belts 106 passing around a nip roller 107 directly beneath delivery de~k 98 and deck ramp 99. As indicated in Fig. lOB, a plurali~y of five feed:belts:`~
: 106 are employed to receive and ad~ance each frontmost : sheet 104 in turn as it descends downward between feed ..
~block 31 and singulatin~ belts 102. Singulating belts :-~
102 are pref@~rably cir~ular in cross section and may be :~
termed "0-belts", and feed~belts~ lO~may:likewise be `~
"C~-belts" as illustrated in the figures.
Singulating belts~102 are posltioned encircling a ~:
guide roller 108 closely adjacent~to nip roller 107 and extending laterally~a~ross the entlre~width of the sheets in eed:block 31. Suitable guide;grooves formed~
in~guide roller 108~accommodate these~singula~ing belts` .~.-;102 and the guide grooves 109 are deep;enough to receive the entire diame~er of belts 102 and actually allo~ the-.
belts-t~avelling around guide roller~108 to be recessed beneath the roller's periphery:~s indicated in:the figures, assurin~ that each frontmost sheet 104 in turn will::tra~el around guide roller 108 without wrinkling.
~Thus, as indicated in Fig. 9, the sheet 104 is~grlpped -:-.
.., ,:

,..
..

W(~ 94/112XX PCI/US~3/10909 be~ween the plurality of feed belts 106 and the periphery of guide roller 108 as it passes between the two rollers 107 and 108.
As indicated in Fig. 9,. the two singulating belts 102 travel in a cl~ckwise`direction around roller 10~
and they each pass an in~ermediate idler sheave 111 as they travel upward to encircle an upper pressure sheave 11~. The two pressure sheaves 112 and a sligh~ly oversi~e ~entral eed roller 121 are all mounted on a stud shaft 119 at the top of singulating feed assembly 105. The arriving feed block 31 of s~acked paper sheets delivers frontmost :sheet 104 into direct contact~with feed roller 121 and belts 102 on pressure sheaves. 112, as clearly illustrated in Fig. 9.
In the perspective view of Fig. 6, ~he full width rollers 107 and 108 may be compared to the idler sheaves 111 and pressure sheaves 11~2 which are merely~wide enough in an a~ial direction to receive and guide the singulating belts 102. Also clearly shown in Fig. 6 and are the mating~ gears drivingly joining the nip roller 107 and the guide roller ~108 for pinch roll type engagement:;at ma~ched angular speeds. Driving torque for these rollers 107 and 108 is supplied by a feed drive mot~r 113 positio~ed ben~ath ~ip roller 107 and:
mounted on t~ inner ~a:ce of a re~ar pedestal plate 114 on which are~mounte~ the bearings supporting the shafts of rollers 107~and 108 as shown ~in Fig. 6. A~timing~ ;
belt dri~e 115 connects the shaft of motor 113 to the shaft~of nip roll~r 107.
A front pedestal pl~te ~16 s~pports corr~sponding shaft bearing~ for rollers lQ7 and 108 and the short lengths of the roller'6 shafts extendi~g beyond the outer face of front pedestal plate 116 provide keyed WO94/11288 21Z6S72 Pcr/us~3tlo9os mountings for the drive gears 117 and 118 dri~ringly joining the rollers 107 and 108 together for matched angular velocity. ~::
A stud shaft 119 provides the rotational mounting for the upper pressure sheaves 112 and the slightly oversized feed roller 121, formed of a soft tractive polymer material, whose diameter is sligh~ly greater than the diarneter of singulator belts 102 as they pass around their respective upper pressure sheaves 112.
Thus, as indicated in ~he igures, the feed roller 121 comes in contact f irst with the f rontmost sheet 104 being delivered on th~ delivery deck 98, just before this sheet 104 reaches singulator bel~s 102.
Stud shaft 119 is journalled in a pair of upstanding yoke arms 122 whose opposite lower ends are pivoted on a trans~rer~ pivot shaf~ 123 ~xtending across the entire width o the singulator shingling mechanism 24, and both ;~`
ends of the pivot shaft 123 are resiliently mounted for -~
hor1zontal movement in mounting s~ots 124 accommoda~ing sliding bearing blocks 126 :in which the pivot shaft 123 are mounted.~ As indicated in the drawings, compression ~;.
coil springs 127 positioned in the mountlng ~slots 124 ~ -resiliently urge bearing blocks 126 ~oward the feed block 31 as indica:ted in detail in Fig.~8. ~ : :
,:
: Th~ diagonal ~upstarlding position ~of yoke arms ~22 is thus determined by the resilient positioning: of: shaft 123 . This positioning: presents singulating belts 102 in : :-the position required for singulat1n~ and feeding frontrQo~t pages 104 into the nip: between rollers 107 and 10~, and at ~he sam~ time the :mechanism mou~ted on :
resiliently biased shaf~ 123 performs a number o f contro~ flm:ctions ~governing the operation of the entire :
aæsembly.
, ;;

WO94/11288 PCT/U~3/10909 ~6S~ 2 - 22 - ~

The two yoke arms 122 are preferably rectangular in shape, and are keyed at their lower ends to pivot shaft 123, and a stud shaft bore at their upper ends in which stud shaft 119 is journalled. The rec~angular shape of these yoke arms 122 is sho~ in Figs. ll and 12 and also indicated in Fig. 6. ~:;

A~tomatic Ramp Feed Control Pivotally mounted on stud shaft ll9 and depending therefrom on the fesd block 31 side of pivot sha~t 123 is a feed start finyer 128. At any time the sheet feed block 31 is not in position with its frontmost sh`eets abutting the feed roller 121, feed start finger 128 depends downward and forward toward the feed bIock with a sensing surface l~9 positioned to provide the second contact of the singulating f~ed assembly 105 with the advancing feed block 31, i~inediately after f irst con~act with feed roller 121. This~is indicated~in Fig.:ll, where frontmost sheet 104 is shown approaching feed roller 121 and sensing surface 129 of feed start finger 128 depending downward from stud shaft ll9. Feed advance of the block 31 continues until eed start finger 128 has been depressed clockwise about stud shaft 119 to the position shown in Fig. l2, where surface 129 has now withdrawn into alignment~with slngulating belts 102 and feed roller 121 carried by yoke~arms 122 pivoting with shaft 123 on b aring blocks 126 and a resupply fe~d advance switch 131 mounted on~an arm 122 has h3.d,its actuating: arm depressed by this counterclockwise movement of start finger l28 to close the switch~131 and terminate resupply feed advance motion of the feed blo~k 31, as shown in Fig. 12 as compared with Fig. ll.

WO94~1128X 21 ~ 6~ 72 PCT/US93/1~9 - ~3 ~

In this position, with frontmost sheet 104 in contact with feed roller 121 and singulating belts 102, normal feed can progress and the frontmost sheets can be f ed sequent i al ly in~o the sheet stream f eeder 9 7 .
ratcheting resupply mechanism for incremental feed advance of feed block 31 is provided by a resupply sensor switch 131 mounted on yoke arm 122, with its actuator arm free for mo~ement toward feed block 31 and away from sheet s~ream feeder 97. Each end of shaft 123 has keyed thereon an aligned switch actuator cam 133 :~
having a sector cutout 13~, subtending approximately 80 degrees along its lower edge b~neath shaft 123, engaging a stationary pin 136 protruding from ~he adjacent face of the pedestal plate 114~or 116 into engagement with the sector cut~ut 134:. Each cam 133 has a spring arm 137 extending radially ther~efrom ~iased downwardly by a ;~
tension spring 138 who~e lower end is anchored to the adjace~t pedestal pla~e. -comparison of Figs. 8~, 11, 12 and 13 shows ~hat in ;
~he feed advance mode of Fig. 11 up to the point where normal feed operatlon begins in Fig. 12, the resupply sensor switch 131 is unactuated to assure normal feed screw ~esupply ~opera~ion.~ As can be seen by compariDg ~ :
the:positions of spri~g arm 137 and spring I38 in Figs. 11 and l~ ~he feed.Eoller 121 is in constant pivotal "tensio~" with~for`emos~:sheet 104 of the feed block 131. If the feed advance of:feed block 31 would ~ :
move si~gulati~g;fe~d a8sembly 105 toward the printer 27 and a~y from the ramp 29, as shown in Fig. 12. As this motion begins, cam~133 has the forward end of its sector:
slo~ 134 engaging:pin 136 as shown in Figs. 8 and 13.
:As such~f~ed co~tinues to advance, causing shaft 123 journalled in sliding bearin~ block~ 126 to be displace~d irl slot 1~4, ea~h ~am 133 is pivoted about pirl 136 and , :

W094/112XX PCT/US~3/109~9 ,2~265~2 each spring 127 is depressed, causing shaft 123 to pivot further and moving the spring arm 137 protruding forwardly fxom cam 133 to rotate upward even further, 6tretching tension spring 138~secured between the outer end of spring arm 137 and the pedestal plate beside it as indicated in Figs. 6,. 7, 11 and 12.
Spring 138 is shown drawing spring arm 137 downward in Fig. 7 in the position it occupies as feed bloc~ 31 first comes in con~act with feed roller 121 of singulating feed mechanism 105. As feed block 31 ad~ances and spring arm 137 is raised to the position shown in Fig. 12, stretching spring 138, the cam 133 pivots on its keyed shaft 123 to the position shown in Fig. 12.
Further advance of feed block 31 causes the entire singulating feed assembly 105 to move counterclockwise :~
to the position shown in Fig. 13, and resupply safety stop switch 132:is opened by the withdrawal of cam 133 rom the switch's actuator arm, as indi~ated in Fig. 13 stopping supply motor M located within column 28 and preventing damage to th~ system. Manual removal~o a sufficient number of frontmost sheets 104 ~rom feed block 31,:or manual reversing tor~ue applied to a crank 60 ex~ending from ~he lower e~d of feed screw 57 (Fig. 2), causes singulating feed assembly 105 to swing ba~k clockwise under the:influence of springs 127 and 138 from the p~sition of Fig. 13 to the normal feed position~ indicated in Figs. 8 and 12, closing switch 132 a~,again permitting free oscillatlon of as:sembly `
105 and shaft 123, and i~itiating resupply feed advance of block 31. Thiæ intermittent operation of feed advance vi:a~feed screw 57, controlled by switch 131, s~ar~ finger 128 and constant pressure of f~ed roller .
.

WC) 94/1128~ 21 2 6 ~ 7 2 P~/US~3/10909 121 controlled by spring 138, assures an ample supply of frontmost sheets 104 for substantially continuous operation of the entire feed de~ice. -~
The sensor switch 132 serves as a safety stop switch; if feed screw 57 delivers feed block 31 in the feed a~vance direction to the point whQre an excess supply of papers sheets is in position, the automatic pivoting ang~lar movement of singulating feed assemk,ly 105 shuts down ~he motor M housed within column 28, stopping feed screw ~7 until any such oversupply movemen~ is correc~ed.
In addition to this articulating feed control movement o~ singulating feed assembly 105, it should ~e noted that an additional adjustment o the sheet feeding operation is provided by the adjustable posi~ioning of deck r,~mp 99 toward and away from the singuIating feed assembly. This adjustable rnovement of the deck brings deck ~dge 101 closer to or arther away from singulat~ing belts I~2 and: feed roller 121.
~ Thus, the notches 103 straddle the singulating belts : 102 to greater or lesser degree.~ Since the:tension of the belts 102~ is constant and the distance betwe~n ;
tangent contact of guide roller 108 and idler sheave 111 is also constant,: the frontmo6t: sheet 104 being urged downward:by eed roller:l21 has to exert greater force:
: to displac~ sinqu~ator belts 102 from their notches 103 ~ -: to~ permit sheet 104 to pass throu:gh. The force required is directly~proportional to the;tension in the ::
singul~or belts 102 a~d;their engagement in no~ches 103, and:in~ersely proportional to the distance between :roller 108 and sheaves 111, and also to the a~gle 100 between the deck ramp 99 and deck 98, whiah ang~e may be ad~usted or varled to suit particular applications.

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WO94/11~8~ PCT/US~3/10909 2~26s~ 2 The slightly greater diameter of roller 121, as compared with the diameter of upper pressure sheaves 112, provides a slightly greater linear velocity of the rim of roller 1:21 as it urges frontmost sheet 104 downward, enhancing the buckling or arching of sheet 104 as illustrated in Fig. lOA and assuring that the f ibre-lock bs:)nd between f rontmost sheet 104 and the ~-sheet directly behind it will be effectively broken during the singulating operation. Deck adjustment allows ine tuning of the efect of this velocity differe~ce for optimum singulating operation.

Sheet Stream:Feeder Mechanism The sheet stream feeder mechanism 97 indicated in Figs. 1, 2, ~ and 7 forms the output or delivery end of :the high capacity sheet feeders o the present invention. This sheet s~ream feed~r is designed for cooperation with~and is supported on the counterbalanced infeed platform :26 of the high capacity feeders, as illustrated in Fig.:l. Illustrated schematically in Fig. 14 is an elevator ~ray 13g of machine 27 or holding a plurality of sheets of paper,~provided with a feed stop 141. The~sheet stream eeder~g7 of the present invention constit~tes a customized conveyor for delivering:new:paper sheets in a~hingled stream which ::
are added to the underside of a feed stack l42 of sheets presented for intake feed to the high volume printer ~27 of Fig. 1.
~ Linter 27 is provided with printer feed belt means 143 shown in Figs. 14 and 15 ~ositioned to engage tra~tive~ly and draw into the printer 27 in rapid successlon~the uppermost sheets from stack 142 on:feed tray 139. Shee~ stream feeder 97 is mounted on cou~terbaIanced platform 26, constructed betwee~ a p~iL

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wO 94/l I~XX 2 1 2 fi 5 7 2 Pcr/us~3/loso9 of cantilevered arms 144 whose proximal ends are pivoted about pivots 145 at the insider lower portions of the pedestal plates 114 and 116, near ramp 29, as indicated in Fig. 6. The distal ends 144A of arms 144 protrude lengthwise toward the left in Fig. 6 for resting engagement directly on elevator tray 139, as indicated -in Figs . 14 and 15, with their outermost ends contacting stop 141. Counterbalancing compression coil springs 140 suppor~ the weight of arms 144, being compressed between arms 144 and the lower portions of the pedestal plates 114 and 116, toward distal ends 1~4~.
First, second and third feed~elt rollers 146, 147 and 148 are all idler rollers, jour~alled for rotation ~:~
in the cantilever:arms 144, with their spaced grooves receiving the feedbelts 106 which are tracti~ly driven ~:~
by nip roller 107, rotated by timing bel~ 115 driven by ~
motor 113 as shown~in Fig. 8. Thus the feed belts 106 -:
pass over the m~tor driven:nlp roller 107, beneath guide ::
roIler 10~. In Figs. 6 and 7, the driving nip roller :::
107 and the three feed belt rollers 146, 147 and 148 are shown arrayed from right to left,~ extending from the singulator feed assembly 105 to the dist;al end of the ~:~
sheet stream feeder 97, with five endless feed belts 106 shown travelling arounid all of these rollers and back for a complete circuit forming a conveyor belt for the :~
stream of singvlated paper sheets:being delivered to printer 27. ~ : :
A sheet support plate i49 spans the distal end of ~the a~embly between the two cantilever arms 144A, slanting gently: upward with grooves accommodating belts ~`
~06 to pro~id~ a final support surfac~ at the terminal end of the:feed path on which:the arriving sheets rest.
A protruding centrial support ledge 151 spa~s the cenitral po~ion:o~ this plate 149 and the central feed belt 106 WO 94~1 128~ Pcr/US93/~0909 ,6~

passes throug~ a slot in ledge 151 and hence downward around the third feedbelt roller 1J~8, leaving each sheet delisrered by the bel~s 10~` in turn resting upon support plate 149 and its support` 1 dge 151.
Flanking the cen~ral support ledge 151 are several stripper fingers 152 extending forward beyond third feedbelt roller 148 and assuring that arriving sheQts will not be wrapped around the feedbelt roller 148 and carried under it back toward the feed assembly on the underside o the shee~ stream feeder 97. Stripper fingers 152 and support ledge lSl thus present the leading edges of all o~ the sheets in feed stack 142 with a slight upward slant, as indicated in Fig. 15, and this promotes the smooth ~en operation of printer feedbelts 143 in drawing each upp~rmost sheet in turn from stack 142. ;

: Sinqulated Shinqled Sheet Stream Feed Control As stack 142 is built up.by the deli~er of ~resh sh~ets to its underside, as indicated in Figs. 14 and 15, the leadlng edges of the stack are determined by stop 141 and the trailing edges of th sheets in the stack are all aligned along a vertical:~rear edge plane 153. Counterbalanced platform 2~6 supporting the shee~
stream feeder 97 is a two part structure, with a ~entral .
sliding carriage 154 supporting second feedbelt roller ~ ..
147 a~ a selected one of a ~arlety of adjustable positions between rollers 146 and 148. ~This carriage 154 is shown 1~ Flgs. 6, 7, 14 and 15,~wh~re it will b~ ..
seen that carriage walls 15~ flanki~g the cantilever arms 144:are joi~ed to each other by the roller 147, whose ends are journalled respectively in each of thè
two carriage walls 156, a~d also by a feedbar assembly.
This ~omprises a leYel s~nsor bar 157 spar:ning ~he .:

WO94/112XX pcT/us~3/los~s 2126~72 ~2 9 - ~
, .

entire width of feeder 97 above second feedbelt roller 147, and pivotally moun~ed on pivot arms 158, positioned outside walls 156. Arms 15~ are joined to each other by a ~ransverse shaft 15~ whose ends extend through journal mountings in plates 156 to be keyed to pi~ot arms 158. ~:~
Bar 157 and arms 158 thus form a pivoting structure, ;~
which allows level sensor bar 157 to swing up and down -~
about the axis of transverse shaft 15~, and to rest o~
the uppermost sheet of sta~k 142 near the trailing edges of the stack close to rear edge plane 153, as indicated in Figs. 14 and 15.
Sliding lengthwise adjustment movement of carrlage 154 is ~uid~d by the shaft of ~he second feedb~lt roller :-147 slidingly mo~nted in a longitudinal slot 1~1 in the cantilever arms 144, as well as by a guide pin 160 protruding inward into:the sam~ slot 161~from a ~entral part of the inner face Q~ each carriage wall 155. As shown in Figs. 6 a~d 7, an ~djustm~nt rack 162 pinned to :, each of the carriage walls 156 extends rearwardly toward :~
the ramp 29, sliding in a longitudinal slot 163 ~ormed in the cantilever arm 1~4.
Each rack 162 in its slot 163 is engaged with an ~:~
adjustment pinion 164, keyed to a pinion shaft 170 :;
extendi~g transversely across the structure ~etween the :
two rack slots 163, and at~least one end of shaft 170 has a manual:adjustment knob 165 mounted thereon for operator adjustment of the pinion 164 to dri~e the rack 162 and the associated sliding carriage 154 toward ox away r~m the end stop 141 a~ the remote end of the cantilever arms 144A.
A~justment of the ~nob and carriage 154 posi~ions le~el sensor 157 directly over the tailing edge of the shee~s in stack 142 and also brings into posi~ion a `
biasing roller 166~ journalled spanning the carriage 154 .
.

W09~/11288 PCT~US~3/iO9~9 ~26~ ~
between its two upstanding walls 156, spaced a few millimeters rearwardly from rear edge plate 153, to allow the surace of biasing roller 166 which is closest to rear edge plane 153 to define a biasing plane 167 as indicated in Figs 14 and 15~. The cross sectional side elevation views of Figs. 14 and 15 ~learly illustra~e the operation of biasing roller 166 in depressing the stream of sheets travelli~g lengthwise from right to ~:
left, car~i~d by the feedbelts 106, as they approach the second feed belt rol~er 147. The ~railing edge of the stack 142 sta~ds above the arriving sheets and slightly overhangs roller 147, whi~h i5 adjus~ed by operation of the adjustment ~nob 165 to assure that roller 147 is slightly forward of the rear edge plane 153t leaving the overhand illustrated in Figs. 14 a~d 15 under which the leading edge of each arriving sheet is delivered by belts 106.
In Figs. 14 and 15 the shingled stream of arriving sheets are shown with their curvatures exaggerated to emphasize their respective relationship with each other. Thus, ln Fig. 14, the fi~st shee~ 168 has already been deliver~d to being the stack 142 with its leading edge against stop 141 resting on stripper fingers 152 and support ledge 151.
P The si~gulating feed~a!ssem~ly 105 and particularly the relatio~ship-of singulating belts 102 and feed roll~r 12I with dec~ 98 and deck ramp 99 assure that ~ach new foremost sheet 104 will start its downward tra~el~.~oward the nip roller 107 before the previous-sheet has completed i~s approach to the nip between ~he nip roller 107 and guide~roller ~08.
Thus, a s~ream of singulated but shingled frontmost sh~ts 104 is delivered to belts 10~, and this shingled s~ream of sheets is shown in Fig. 14 arri~in~ at biasing WO g4/t 128~ PCr/US~3/109~9 2I26s72 roller 166 and sliding beneath the trailing edge of the pre~iuus sheet 1~8. Secon~ shee~ 169 is thus shown to be halfway along the underside of sheet 168, and the following sheet 171 is also partially underlying ~he trailing edge of sheet l~9, with the next following sheet 172 similarly extending under the tailing edge of ~heet 171.
A later series of sheets 169, 171, 172 are shown in Fig. 15, all being delivered successively to the underside of ~tack 142: and carried by feedbelts 106 to the stop 141, where they are stripped form the belts ~nd ~:
raised by th~ next following sheet as the stack grows in height from the initial sheet shown in Fig. 14 to the ~:
stack of sheets 142 shown in Fig. 15, from which fe~d printer feed belts 143 successively draw the topmost she~t into the prlnter 27. ~
The counterbalanced tray~ 2~ remains stationaxy ~from the momen~ elevator tray 139 raised it originally to bring stack 142 into contact. with the printer ' s feed mechani sm 143 . : :
As stack 142 :rises, level sensor bar 157 is .
displa~ed upward, and when the ~stack ~eaches the desired ~i .
height, as indicated ~in Fig.: 17 as compared with : Fig . 16, the r~sulting angular upward movement of pivot ~:
D arm 158 beside the rear carriage wall 156 allows a feed sensor switch 173 to open, stopping motor 113 and i~nterrupting the operation of singulatin~ belts 102 and ~eed belts 106 until t:he printer has drawn stack 142 dowr~ ~,a poi~t where arm 158 again closes feed switch 173, resuming normal feed operation of the: device.
Manual adjustment o~ the adjustm~nt knob 165 indexing rack 162 along i~s slot 163 allows the sheet '..
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WO94/11288 pcr/us~3t1o9o9 6~

feeders of this invention to accommodate sheets of any required length, such as ll inch, 13 inch, l4 inch or any other desired length of paper sheets.

Ink~rface With Drawer Loaded Sta~k Feed Host Machines Th~ foregoing description relates to a sheet feeder adapted to interace with a printer or other "host"
ma~hine ha~ing a side mounted shee~ stack sing11lator mechanism. The stack is normally loaded into the printer by ope~ing a panel and placing the stack of sheets on a moving elevator platform that brings the topmost shee~ into contact with the singulator. As noted above, Applicant contemplates the use of the sheet feeder according to this invention with printers, photocopiers, and other types of host machines such as the Xerox~ model 4090 and IBM models 3827/28 as well as the similar Kodak msdel 1:392 printer ~hat utilize a stack of sheets loaded into a movable drawer with a feed elevator that raises and low~rs the stack.
Fig. 18 illustrates an alternative embodiment of the sheet feeder 2;1a according to this invent1:on adapted to interface with a drawer fed prlnter :27a.~ The feeder mechanism accesses the lower feed~drawer 200 directly through the front of the printer. The printer illustrated herein.is exemplary of a Kodak or IBM type printer having an upper drawer 202 and lower drawer 200 along its front side 201. The upper drawer 202 is: ~:
adapt~d ~o hold, for example, l,OoO sheets ~while the ;
taller~l~wer draiwer 2U0 is adapted to hold, f~r example, 2,500 sheets. The high speed sheet feeder 21a of this e~bodiment,: by accessing the lower drawer 200, allows the user to also manually access and load the upper drawer 202 without interfering with the operation of the sheet feeder 21a in ~bie lower d~awer 200.

'':' WO94/l1288 P~T/US93~10909 Fig. l9 ~urther details the printer. As will be described fur~her, the lower drawer 200 has been :~
modified to ac~ept a feeder tray according to this embodiment . The upper drawer 202 can also be modif ied to accept a feed tray, but for illustration, the lower drawer 20~ modification is discussed herein. The lower drawer 200 includes a front 203 and an enlarged portal ~ ~
204 for accepting the tray. The printer 27a is mounted ~-o~o a set of blocks 206 tha~ includes a track guide block 208. A set of tracks 33a extend outwardly from this block 208 perpendicular to the drawer fronts . The sheet feeder 21a moves along this track as detailed in Fig. 18. Unless o~herwlse discussed, it can be assumed that components ar~ s~stantially the same in form and function as those described~above for the sh~et feeder 21 of tha preceding embodiment.
Fig. 20 illustrates the:end:view of the sheet: feeder 21a accordi~g to thi:s embodime~t. Unlike the embodiment ;:
of Fig. l, the feed~ray 210 has been lowered relative to the support column 23a so: that sheets f rom the stack ~
31 can be di~ected down to the location of the ~prînter ' s :~.
lower drawer 200. Sheets :are driven by the singulating f~ed assembly 105 ~which ls ~substantially similar to tha~ describéd above)~ down a ` series of inte~mediate :
~rertical bridging ibelts .212.~h~ch,:: in this~ example~ can comprise circular cross-section: urethane belts into the lowered feed tray assembly 210.: As noted, the level of the feed tray; 210 relative to the su~?port columrl 23a is: :
chosen ~o align: i~ with the portal: 204 in the printer:
lower ~drawer: front 203. ~ The she~t feeder corltrols 214 according to this embodiment can be mounted on:the : ~ ~;
reverse side of the support column 23a~ from those shown .
for the sheet~ feeder 21 in~Fig, 1. This allows easier manipulation of the con~r~Qls for: the par~icul:ar prir~ter WO94/11288 PCT/US~3/10909 ,6$~
- 27a to be interfaced in this example. The controls 214 can be mounted on either side of the column 23a, howe~er, depending upon the prin~er with which to be interfaced. Similarly, the unlocking bar ~la and associated pi~ot arms 42a can be reversed compared with the sheet feeder 21 of Fig. 1. Their operation is substantially the same as previously di~cussed, however.
Fig. 21 further details the printer drawers 200 and 202. The drawers house moving sta¢k feed elevator platforms 215 and 216 that raise and lower stacks of ..
sheets posi~ion~d thereo~. The stack feed elevator platforms 215 and 216 are inclined so as to support stacks at an angle ~typically 20~) relative to the ground. The standard drawer fronts 218 and 220 normally :.
found upon the printer are replaced with a modified lower front 203 having the portal 204 and modified upp~r ;~
fro~t 222 having a small orifice 224 along its right hand side. The orifice in~the upper right hand corner ~.
of ~he upper drawer allows the cylindric~al interlock probs 226 (Fig. 20 ? on the sheet feeder column 23a to engage an internally mounted interlock guide block 228 detailed in Figs. 21A and ~lB. The interlo~k is . designed to insure proper alignment of the tray within the printer drawer 20Q and can also s~rve as a safety :~
interlock to prev~t accide~tal pull out of the feed tray 210 from the drawer 200 during operation.
~n additional modification that is accomplished in order to allow the feed tray 210 to enter the printer ~.`
drawer ~00 is the reduction in the height of ~he sheet ~:
. .--, ~
stack edge guide 230 as illustrated in Fig. 22. The guid~ is part of a screw mechanism 229 that allows cen~ering ~f she~ts of varlous size OIl the platform 215. Thus, it is a desirable feature to retain should th~ prin~er 27a be used without the sheet feeder 21a at ,.

:

WO 94/~1288 2I 26S 72 PCr~US~3/l~sO9 certain times. Howe~er, ~he unmodified guide 230 normally extends into path of the feed tray 210 as i~
passes through the portal 204. The normal height of the guide 230 is shown in phantom. The guide is, thus, lowered to a height that allows passage of the tray :`
thereover. As rloted, since the printer 27a according to this embodiment is designed l:o remain usable without the feed~r mechanism 21a attached thereto, a movable extension 232 of the guide 230 is provided~accordin~ to this embodime~. The extension 232 allows the guide 230 to resume its full:unaltered height when needed. The extension 232 comprises an additional piece of rectangulax material 234 that slides upwardly and downwardly ~arrow 238) relative to the lower guid~ :
se tion 236. The guide extension includes a knob 240 that allows easy grasping~of the extenslon's end for lifting and lowering of it relative to the lower guide section 236.
~ The front face 242 of the sheet feeder column 23a (Fig. 20) and:the opposing lower drawer front ~03 can each include intermeshing ssrips of hook~and loop:
materiaI such as Velcro~.: Thus:, when the:feed tray 210 is passed~into the drawer 200 through the portal 204, the hook~and~loop material:244 and~246 on each of ;the column face-242,: or another convenient location~and the drawer front 203 become intermeshed and:hold the drawer 200 and column 23a firmly to each other. For example, in one embodiment the Velcro~ is 2ttached to an ad~s~abl~bracket located under the sheet f@eder ~:
; tray 210~ Hence, when the sheet feeder ~21a is pulled : rearwardIy:~n:it:s tracks 33a away from the:d~awer 200, (generally:~ollowing electronic unlockin~ of the:drawer 200) the drawer 200 is urged to ope~ with the sheet feeder 21a attached there~o, revealing the WO94/1l2X8 PCT/US93/10~9 .,.~
~6~ 36 -interconnection between the tray 210 and the drawer 200. Pulling the feeder 21a beyond a certain point, will break the adhesion between the strips of hook and loop material 244 and 246 allowing the sheet feeder 21a to be separa~ed from the drawex 200.
Reference is now made to the sheet feeder tray 210.
The tray 210 according to this embodiment is fed by means of opposing sets of subs~antially verti~al elas~omeric bridging bel~s 21~ that direc~ she~ts do~wardly from khe singulating feed m chanism 105. The singulating feed mechanism 105 is substantially similar to that described in the embodimént of Fi~. 1. As further detailed in Fig. 20, the bridgi~g belts 212 are carried by two sets of opposing rollers. The upper roller 108a~ and nip roller 107a are mounted in ~he upper portion of :the colu~ul 23a between side panels 114a~ and 116a. The lower belt rolle~s 248 and 250 are, as shown in Fig. 23, mounted within side plates 252 and 254 that exterld outwardl~: from the support colurnn 23a . The sid~
plates 252 and ~54: lnclude, at an outward end ~hereof, pivots 256 for mo~ting the inboard end :feed tray 210.
. .
The tray 210 has a lower platform 258 with a set of three flat elastomeric ~elts 260, 262 and 264 positioned thereon. The: belts 260, 262 a~d 264 rotà~e to driv~
sheets along the: :lower platform 2~58. An upper platform 266 is mount~d on spacers: 26~ ovPr the lower platform ;~
258 and def ines approximately a 1/4-1/2 inch space }: etween opp~sing plat orm f a~es .
Th~ lower platform 25~ and belts 260, 262 and 264 axe more clearly illustrated in Fig. 23A:which shows th~
upper platorm :266 removed and details the interconnection between the central drive motor 270 and the b~lt drive roller 272. This: roller 272 carri2s each of the belts 260, 262 and 264 on its surface. The ' WO94/11288 ` 2126572 PCr/US~3/10909 roller 272 is driven by a timing belt 274 interconnected with the motor 270. As detailed by belt 264, ~he outboard ends of the belts are located in slots 273, 275 and 277 in the lower platorm 25B. The slots include rollers which, in this embodiment comprise needle bearings 276. The bearings have a width that is less than the width of the belts. The belts 260, 262 and 264 are urged by t~sion to remain Gentere~i upon their respective beari~gs 273, 275 and 277. A secs)rld ~et of supporti~g bearings 278 can be provided along the middle of the platform 258.~
The belts 260, ~62 and 264 in this embodiment comprise a polyurethane or other suitably frictional ma~erial. As shQets are driven fro~ the bridging belts 212 on to the flat elastomeric belts of the lower platform 258, they encounter a weighted roller whi~h, iIl -thls example, compr~ises a ball bearing 280 ~positioned within a hole in the upper platform. The:ball bearing maintains the sheets against the~elastomeric belts 269, 262 and 264, thus 1nsuring ~hat the sheets are f irmly gripped by the ~belts as :they move alon~th~ feed tray 210. The lower platform 258 includes side guides 282 and 284 along either lengthwise edge to insure that the edges of the sheets moving therealong maintain correct alignment relative to ~the tray 210.
As will be described ~urther below, the side guide -282 along the right edg~ of the feed tray 210 has been removed proximate the distal (downstream) end of the tray...~;imilarly, a rectarlgular portion of the distal end o~ the right platform 258 edge has been remo~red, thus~ creating a sub~tantially rectangular cutout 286 in the; pla~form 258. ~ft~r the leadin~ (downstream~ ~ edges of each of the 5heets has passed under the ball bearing ~:
280, it is then driven under ~ guide plate 288 and a WO 94/l 128~ ~ PCr/US~3/10909 ~,~ ?,6S~ ~
rod-like guiding or "stacking" roller 290 that extends a~ross the width of the tray 210. The leading edges of the shee~s impinge betw@ën the stacking roller 290 and the belts 260, 262 and~ 264. ~ote that the right side 292 of the guide plate 288 is angled downwardly. The leading edge of ea~h sheet on the sheet' s right side is driven under this angled guide plate 292. The driven .
sheet edge is f ree to bend downwardly over the open cutout 286 alorlg the distal portion of the tray since the edge is removed. The reason for forming this bend `~
will be disc:ussed further below. .
Sheets are dri~ren along the feed tray 210 until their leading edges ~ontact the auxiliary s~op 294 posi~ioned at the downstream end of the tray 210 be~ween the upp~r and lower platforms 266 and 258. The stop 294 ~:
includes a thum~ screw 295 and a groove 297 so that it can be slid and locked into~different positions along the length of the upper plat:form 266. :
Th~ stacking roller 290~serves to direct l~ading edges of sheets downwardly as they pass therethrough. ~.
Further dawnstream sheets which now rest against the:
auxiliary stop~294 are held~:in a substantially planar orientation with their traillng~edges susp nded above the bottommost edge of th~ roller~290. Accordingly, as new leading edges enter the downstream (distal) portion of the tray 21:0, these leading:edges pass under :the ~ -~
sheets that are:already present on the tray 210. Hencei :
a s~ack is conti~uously:formed by adding:additional sheets.to the bottom of the stack. It is contemplated that a stack size of approximately ten~sheets is malntained at all times at the downstream end:of the ~:
~ray.

',;
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WO94~1128~ 21 2 65 72 PCT/US~3/10909 Stack size is maintained by means of a sensor 296 comprising, in this emhodiment, a microswitch 298 ~hat is activated when the thickness of the stack decre~ses below a predetermined num~er of sheets. The microswitch 29~ sends an instruction to the feeder controller circuitry (not shown) instructing the shest singulating drive 105 and vertical bridging belts 212 to transfer additional sheets to the tray 210. The sheets are transferr~d co~ti~uously until the microswitch 298 is deactivated, indicating presence of a sufficient number of sheets in the ~ray stack. A se~ond sensor:300, upstream of the stack level sensor 296, is also provided according to ~his embodiment. This sensor's microswitch 301 is activated upon a decrease in stack size:below a second predetermined level, indicative of a feeding jam in the sheet feeder mechanism. The sensor 300:signals a jam alarm (not shown);and:can inst:ruct the sheet feeder 21:a to shut down operation.~
Fig. 24 illustrates the interfacing of the feed tray 2lO with the printer mechanism:. The feed tray ~lO
includes a plurality of sheets:30:2 in its s~ack 304 having right~edges bent downwardly over~ the rlght edge cutout 286 in the lower:platform 258. :As noted~above, the printer s~tack:platform 21S in this embodiment is slanted at an angle:A relative to:the horizontal.: In thi~s embodiment, A e~uals~approximately 20.; The tray :
219~is positioned so that~the sheèts 302 o~ ~the stack 304~are placed into~:contact with a si;ngulat:or drum 306 ~hat ~ates ~o drive sheets out of the;stack and through a nip~rol1er 308.
~ In ;unmodified operation, a sheet stack 310~ (shown in pAantom~ wou~ld;be placed on the platform 215 with its right ~dg~ 312 ;resting against an angled wall ~14 that is~stationary~relative ~o the platform 215 (see:also :

WO94~ #8 . PCT/US~3/10909 ,6S~
- 40 - :

Figs. 21 and 21A). As discussed above, there is shown a -side guide 230 with a movable upper edge 232 that is also stationary relative to the elevator platform 215 and assists in retaining the front and rear edges of the stack 310.
The elevator platform 215 is moved upwardly and ~;
downwardly (arrow 316) by means of a chain drive 318 ~
having lifting link 320 that ~ngages the platform 215. ;:
The chain 318 is mounted between an upper sproc~et 321 and a lower motor driven sprocket 322. The motor 324 is controlled by a platform ele~ation.controller circuit 326 that forms part of the printer's overall operating ~:
circuitry (not shown). Absent the presence of the feed tray 210, the normally loaded s~ack 310 would be elevated in the pIa~form 2l5 by the motor 324 until the ~op ~ace 328 of th~ stack 3:10 contacted ~ sensor switch 330. Further advance of the stack toward to the sensor switch 330 causes the swikch to activate, signalling ~he controller 326 to stop the rnotor 324. Each time a sheet is driven ~rom the stack by the singulator drum 306, the `;
stack size decreases causing, at selected intervals, the sensor switch 330 to ~rop ~ arrow 332 ) signalling the platform elevator controller 326 to again raise the :
pla~:form 215 until arl appropriate stack height is again attained. The process cont~nues until all sheets in the ~:
stack 310 are exhausted.
~eference is again made to operation with the sheet ~:
feeder 21a interfaced with the printer 27a according to -`
~his ernbodiment. The feed tray 210 according to thls inve~tion is adapted to take advantage of the abo~e-described platform feed operating sequence in order to continuously feed sheets from the tray 210. As ~:~
noted above, the ~ray carries a predetermined number of sheets, typical~y ten to fift~en, in its stack. When WO 94/11~8 ~ 21 2 ~S 72 PCI~/US~3/109~9 the shee~ feeder 21a is wheeled on the tracks 33a so as to direct the tray 210 through the drawer portal ~04, its elevation is slightly below the singulat~r dr~
306. As noted, the tray pivots upwardly r~lative to the support column 23a. The pivot height is selec~ed so that th~ tray 210 becomes substantially horizontal when pivoted up to the height of the singulator drum 306.
The righ~ downstream edge of ~he tray has been removed creating the cutout 286 so that the sheets can bend downwardly against the singulator drum 306 as illustrated. The normal feeding orientation for the sh~ets is approximately 20 (angle A) relative to horizontal. The cutout 286 ena~les the right edges of the sheets to drop downwardly under pressure of the singulator drum 306 into an angle that substantially equals 20. ~ence, the sheet edges can:simulate the angled sta~king normally utilized by the printer drawer 200 without the need of angling th~ entire:feed tr~y 210. As a; result, a more xeliable feed tray can be~
con~tructed without compromising the preferred feeding orien~ation of ~he printer. Reten~ion of the preferred feeding orientat~ion ensures that a wide variety of shee~
thic~nesses and textures can be reliably fed by the printer.
: It should be apparent from F1g. 20 that the do ~ wardly angled guide plate 292 is present to ensure that the right edges of sheets en~ering the bottom of the stack 304 are driv~ under ~he bent right edges o~
sheets_in the stack 30~4. Otherwis~, ~he lea~ing edg~s:
of entering shee~s would strike the bent edges of ~he stack 304.
The singulator drum 306 according to this e~diment includes a ~racuum surfa~e that sucks the~uppermost sheet against the surf ace . Each shee~ is adhe~d to the WO94/11288 PCT/US~3/10909 ~65~ 42 -singulator drum surface and driven out between the drum 306 and a nip roller 308 to an image transfer point ~ot -;
shown). By providing a tray edge that allows sheets to ~:
be bent into a configuration substantially similar to `:
those of the sheets in the normally loaded stack 310, effec~ive singulating of. sheets is enabled despi~e variations in surface texture and thickness. The shee~s are basically placed into the same configuration as they would be if a stack 3l0 on the elevator platform 2l5 were prese~ted to the singula~or drum 306.~ ~
As no~ed aboYe, the feed tray 210 is normal:1y ~ ;;
suspended somewhat below the singulator drum on its pivot points 256. It is pivoted upwardly into conta~t with the singulator drum 30~ by engagement of the b~se ~:
334 of the ~ray 210 with the left edge of thQ elevator platform 215.: Once the drawer 200:of the printer 27a closesi its circuitry is au1:omatically~triggered to :
:~raise the platform 2l5:until;the sta k~level senso~ 330: ::
: : signal:s the platform~elevator controller 326 to stop the : :elevator motor 324.~; Hence, upon closing of~ the drawer 200,~the platf:orm 215 rises until it begins ~o raise the : tray 2}0 upwardly toward~the singulator~drum 306. The ~:
~upper~platform~256:o~f; the tray 210 then contacts the ~ :
sensor 330. The sen~or 33Q "thin~s" that the face of t ~ ~he~:normally~loaded stack (310);has reached its desired upward l~vel: of travel.~:The~platform elevator motor 324 is, thus, signaled to stop. ~At:this t~ime, the p1atform~
Z15 is positio~ed as shown in phantom. The platform ~wil1 remain in its;r~ised position as long as the tray ~l0 is located:in the drawer.: To remove the tray 210 ~ : :
rom the drawer 200, it is n~cessary to instrl1ct the ~
prin~er 27a (usually via:i~s con~roI panel 331 shown in ~.
Fig.~l9) to:lower th~platform 2l5~. Th1s usually takes~
the form o~ an "ADD PAPER" command ~ha~ lowers the : ~ platform 215~and allows the drawer to be unlocked.

:: ,'~

, WO 94/1 1288 PCI`/US~3/10909 Fig. 24 also more clearly de~ails ~he tray feed supply sensor 2~6 and similarly constructed jam sensor 300. The ssnsor 296 comprises a microswitch 298 mounted above a small ball bearing 336. The ball bearil~g 336 rides within a hole 338 in the upper platform 266 and can move in all degr~es -o freedom, thus facilitating ~oth linear and side-to-side motion of sheets in the tray 210. As sheets 302 are drive~ out of th~ stack 304 to the side by the singulator drum 306, the tray stack 304 decrea~e~ in thickness. The ball 336, thus, lowers ~ausing ~he microswitch 298 to activate. In respo~se to the switch 298, more sheets are added to the bottom of the stack 304, increasing its thick~ess and raising the ball 336. When the stack reaches a predetermin~d thickn~ss, the switch ~98 is again deactivated signalling the sheet feeder mechanism to cease feeding shee~s to ~he tray 210.
The above-described sheet feeder ~mbodimen~ is ~:
particularly suit~d to printer units having stack feed elevator p}atforms tilted on an angle and positioned in movable drawers~. The singulators of such units are typically fixed within the interior of the machine and do not move relative to the drawer. The sheet feeder mecha~ism according to this in~ention can also be adapted to interface with self-contained singulator and stack feed el~ator platform drawer~ass~mblies such~as those utilized in the Xerox~ model 4090 printer. The adaptatio~ of a print~r 27b having such a sel~-contained drawè~ nit 340 is depicted in Fig. ~5. A set of tracks 33b is located to a~ess the lower drawer~uni~ 340 of this printer 27b.
An unmodified low~r drawer 342 is shown in Fig. 26 for illustration of the draw~r's operation and required modifications for interfac~ with a she~t feeder , WO 94/1 1288 PCr/US~3/10909 2126s7~ ' according to ~his invention. Note that the drawer 342 comprises an elevator platform 344 having a movable rear edge guide 346 and a set of four lead screws 388 that move the platform 344 upwardly and downwardly upon demand. The sheets of a st~k (not shown) positioned on the platform 344 are driven- to an image transfer point (not shown) by means of a singulator belt 350 and lower nip roller 352. The singulator belt 350 according to this embodime~t pivots upward~y and downwardly and ~-includes an internal sensor~that detects upward pl~oting of the bQlt 350. In oper:ation, ~he elevator platform 344 is directed to rise by the printer~s control ~:
circuitry until the stack face pivots the singulator belt 350 to a predetermined upward point, thus indicating that the stack is completely in contact with the ~elt 3~0. As sheets are removed from the stack, the belt 350 drops on its pivot cau~ing the~elevator platform 344 to again rlse so as to maintain the face of ~;
the stack in constant contact with the belt 350.
~ Printers such as~the~Xerox~ model 4090, 4135 and other related models include a double interlock system in~which the user must activate a tray:unlo~k control : 351 on the front 353 of the~drawer 3~2 (Fig. 26) and/or on the contro:1 console:354 (Fig. 25) and then wait until : :~
the platform 344 has lowered. The user can the~ open ;~
the drawer by pulling up on the hand operated drawer latch handle 3S6. : ~.
Fig. 27 details a modification to the drawer ront :~:
~57 o printer 27b in:order to allow a feed~tra~ to e~tex therethrough.; The door latch 358~has been shortened so as to create a widthwi~e channel 360 on the left hand portion of the drawer front 357. The angled :~
~panel 362 loc;a~ed below the drawer latch handle 358 has ~;
been modified to include a pivoti~q doo- 364 tha~ can ;~;

W094/11288 PCT/US~3/1090~

pivot into a flat position as shown by the arrow 366.
The door 364 can be released to pivot downwardly by means of the latch button 368 positioned on the left hand face of the drawer front 357. The drawer front 357 has been further modifîed ~o include an orifice 370 on the right hand side thereof. The orifice 370 allows entry of an interlock probe on the support column 23b of the feeder 21a which will be described further below.
The drawer i~terlock disables the drawer latch handle 358 since it is not-~ormally accessible ~hen the printer 27b is intPrfaced with the sheet feeder 21b. The orifice 370 also serves to align the shee~ feeder 21b with the drawer 342.
As depicted in Fig. 28, the door 364 on the drawer 342 is pivoted downwardly as shown by the arrow 366 and the eed tray 374 of this e~odiment is inserted through the resul~ing port or channel 360 ~lon~ the dashed line 378 as shown. As the tray 374 is fully in~erted, the support column 23b approach0s a face-to-face engagem~nt with the drawer front 357. As depicted in Fig. 29, the interlock probe 382 on the support column 23b engages the orifice 370 causing the drawer }ocking pin 384 to retract as shown by the arrow 386. The drawer latc handle 358 is, hen~e, disabled and only the interval electronic (control acti~ated) locking mechanism remains to lock and unlock the drawer 340.
With reference to Flgs. 26 and 30, the stack elevator platform 344 of this embodiment is supported at four th~aded corner brackets 390 on four revolving lead screws 388. Th~ lead scr~ws 388 are each driven at thei~ bases by belts 392 interconnect~d with a drive motor 394. The screws each turn at an equal rate to :~
raise and lower the~pl~tform evenly. The front end of the platform ~roximate the door includes a housing 396 ' ;:
. .

wo 94'12~ 6 S 7 2 PCr/US~3/lOgO9 for mounting the ron~ set of lead screws 388. A set of upper and lower bearings 398 and 400 are positioned on each end of the housing 3 ~. As the screws 388 turn, the corner bracl~ets 390` ;~de upwardly or downwardly upon them depending upon the direction of screw rotation.
As shown in Fig. 26, the housing 396 is essentially ~he same h~ight as the ur~nodified drawer front 353. As ~:
such, the housing 39~ effectively blocks the entry of the f~ed ~ray thereinto ~ The drawer 340 is therefore modif ied according to this embodiment ~o r~move at least the top portion of the housing 396. As depicted in Fig. 31, the modified front set of screws 402 are shorten d by a distance H`without interfering with ~he full upward extension of th~ platform 344. However, when removing the housing 396, the front screws 40~ must b~ stabilized~so that they do not sway since:the upper bearings 398 are removed with the top portion of the housing. Stabilizatiorl is accomplished:by pro~iding a `
cantilevered b~aring 404 below the level of the drawer ba~e 406~to:each screw 402. The cantilevered bearing 404:on each screw 40~ pro~ides additiona1 suppor~. A~
~racket 408 for:each cantilevered bearlng 404 is provided and should be spaced suficiently from the base :~
406 to prevent swaying of the uppermost~portion of:each: ~::
fron~ screw 402. As depicted, each screw 402 must:be , :
extended d~wnwardly sufficiently to meet the ~: cantilevered:beariny 404.
As depicted;in Fig. 3~, the lowered profile of the ~front ~rews 4 02 enables the feed tray 374 to be slid ;~
into the modified drawer 340 as show~ in phantom. The platform 344 can then raise the tray 374:into contact wi~h the drawer~'s sinqula~or belt 350.
Fig. 33 further details th~ feed tray 374 according ~o this ~mbodime~t. The vertical bridging belt~ 410 : guide sheets to ~he feed tray 374 in a~manner similar to ::

.

WO 94/112~8 2 1 2 6 5 7 2 PCr/US~3~10909 ~hose described for the preceding embodiment. The tray 374 is also conf igured substantially similarly to that showrl in Fig. 23 for the previously described embodiment. This tray 374 generally differs in its exact elevational lo~ation on the support column 23b in order to interface with a differ~nt printer drawer than that of Fig. 23. This tray 374 also differs in that it includes a full width uncu~ edge 412 along i~s right side a~d an edge guide ~14 that extends substantially the full length along the right side. There is also an ~b~nt guiding plate 416 positioned between the upper ~-and lower platforms 4la and 420. The~starking roller 290 is substantially similar to that of the preceding embodim~nt. ~ote that th~ edge guide 414 has a low~red profile section 422 downstr~am of th~ sta~king roller 290. The tray sheet stack~:is positioned proximate this section 422 of the edg~. Tlus, the edge guide 414 is lowered at ~his poi~t so that the uppermost sheets of the stack can pass out of the stack to ~he r~ght as th~y are dri~e~ by the drawer's singulator belt 350. ~The tray 374 includes feed and jam sensors 2g6 and 300 as well as a similar adjustab:le auxiliary stop 294 accordîng to this embodimen~.: A~ball bearing 2~0 mounted in the upper platform 418 is also provided upstream o the guiding plate 416 and s~acking roller 290.
Additionally, as il~ustrated in Fig. 33, the fe~d~
tray 374 of this ~mbodiment includes an additional : ;~
I elas~m~ric drive beI~ 419 along the right edge of the lower platform :~20. This belt is provided to insur~
ade~uate transfer of sheets to the end o the tray. In the preceding~embodiment, this area was occupied by a autout 286.

'';
, W094/11~8~ PCT/US~3/10909 ~2~7~
- 48 - ::

Fig. 34 illustrates a cross-sectional front view of the feed tray 374 interfaced with the drawer 340. Note that the front l~ad screws 402 are lowered to a position below the tray in compari`son to the normal height rear lead screws 388. ThQ~rear lead screws 388 still include their associated bearing housings 424. Note also the presence of ~he cantilever bearing brackets 40~ and bearings 404 for the front lead screws 402. The platform 344 can b~ raised and lowered by the screws 388 ~.
and 402 as shown by the arrow 426. In a~ uppermost position (shown in phantom) the platform 344 bears upon the lower surface 428 o~ the feed tray 374 causing the supported stack 430 of sheets 432 to contact and raise the sin~ulator belt 350 upwardly. The upward movement of ~he singulator bel~ 350 is deteted by the belt's internal sensor 434 (shown schematically) which can ;~:~
compri~e an opti~al sensor according to this embodiment.: Th~ sensor 434 instructs the lead screw drive motor 394 to stop when a suff1cient stack height has b~en reach~d. Again, as in the preceding embodiment, the tray elevation controller 436 is ~.
"tricked" into thinking that the front;~;face of a normally suppor~ed st ck has been presented to the singulator belt 350. In~eality, the much smaller t continuous~y r~plenished stack 430 of th~ eed tray 374 is present~d to the singula~or belt 350. :~
~As sheets:432 are:driven rightwardly out of the tray stack 430, the feed ~ensor 296 o~ the tray 374 directs the f~.edex singula~in~ mechanism and b~rid~ing belts to deliver additio~al sheets to the~u~derside o the tray ~stack 430.~ As su~h, a constant predetermined stack : thickness is maintained. No~e that in~both of the preceding examples, by delivering sheets to the underside of the stack, these newly added sheets do no~ ~

~ .

.

W094/11~88 2 1 2 6 ~ 7 ~ P~/US93/10~09 _ ~9 _ interere with the operation of the printer singulator.
Similarly, the printer singulator does not interfere with the entry of these newly added sh~ets into the tray - stack. The tray feed -sensor 296 is more sensitive than the singulator belt sen~or 434. As such, she~ts are replenished ~o the tray 374 by operation of the feed se~sor 2~6 lo~g before the singulator belt 350 drops far enough to signal a rise in the stack elevator platform 344. -It will thus be seen that the objects set forth above, and ~hose made apparent from the prec~ding description, are efficiently attained and, since certain changes may be made in the a~ove construction withou.t `~
departing from the scope of the invention, it is intended ~hat al 1 matter contained in the abo~e description or shown in the accompa~ying drawi~gs shall be taken by way of example and:shall be in~erpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are in~ended to cover all of the generic and spe~ific features of the invention herein described, and all statements of the scope of the invention which, as a ~matter of:la~guage,~might be said to fall therebetween.
What is ~claimed is:

. . .
.: :
:

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Claims (22)

1. A high speed sheet feeder for directing sheets to a host utilization device having a stack feed elevator platform accessed by a drawer, the sheet feeder comprising:
a feed ramp for supporting a stack of sheets;
a feeder singulator for deshingling sheets from the stack, a feed tray remote from the feeder singulator for receiving sheets from the feeder singulator, the tray including a space for forming a second smaller stack of sheets therein and the tray further including an opening proximate the second stack so that sheets can be slid from a top of the second stack; and the feed tray being constructed and arranged to pass through a port in the drawer of the utilization device so that the second stack of sheets is positioned proximate a utilization device singulator that is located adjacent the drawer.

2. A high speed sheet feeder as set forth in claim 1 further comprising a pivot positioned on the tray so that the tray is raised and lowered by a stack feed elevator platform in the printer to bring the second stack of sheets, respectively, into and out of contact with the utilization device singulator.

3. A high speed sheet feeder as set forth in claim 2 further comprising a plurality of substantially vertical bridging belts for directing sheets from the feeder singulator to the tray.

4. A high speed sheet feeder as set forth in claim 3 wherein the tray comprises a lower platform and an upper platform, the stack opening being defined in a space therebetween and the lower platform including a plurality of conveyor belts for transporting sheets along the tray to the second stack.

5. A high speed sheet feeder as set forth in claim 4 wherein the tray further comprises a stacking guide that directs sheets fed by the conveyor belts to a position in the stack between a bottom face of the stack and the lower platform.

6. A high speed sheet feeder as set forth in claim 1 wherein the tray includes a slot along a side thereof for allowing; sheets to be slid from the top of the second stack by the utilization device singulator in a direction substantially transverse to a direction in which sheets pass from the feeder singulator to the tray.

7. A high speed sheet feeder as set forth in claim 6 wherein the tray includes a recessed edge proximate the slot for allowing overhanging sheet edges to be bent downwardly in contact with the utilization:
device singulator.

8. A high speed sheet feeder as set forth in claim 1 wherein the drawer includes a front having a selectably releasable door therein for receiving the tray.

9. A high sheet feeder as set forth in claim 8 wherein the feed ramp includes an interlock probe and wherein the drawer includes an interengaging orifice for receiving the probe, the interlock disconnecting a drawer lock for enabling the drawer to be opened and closed in conjunction with the tray interconnected thereto.

10. A high speed sheet feeder as set forth in claim 8 wherein the drawer includes a stack feed elevator platform having a plurality of feed screws thereon for raising and lowering the platform, a pair of feed screws proximate the drawer front being lowered to allow positioning of the tray thereover, lower ends of the screws being supported by lowermost bearings on brackets extending below a base of the drawer.

11. A high speed sheet feeder as set forth in claim l further comprising a feed sensor for detecting a thickness of the second stack, the feed sensor being interconnected to the feeder singulator so that a thickness below a predetermined level signals the feeder singulator to direct additional sheets to the second stack.

12. A high speed sheet feeder as set forth in claim 11 wherein the feed sensor comprises a ball bearing engaging the stack and a microswitch positioned over the ball bearing so that vertical movement of the ball bearing alternatively activates and deactivates the microswitch.

13. A high speed sheet feeder as set forth in claim 12 further comprising a jam sensor positioned on the tray upstream of the feeder sensor, the jam sensor detecting a second stack thickness below a second predetermined level, the jam sensor signalling a jam alarm in response thereto.

14. A high speed sheet feeder as set forth in claim 1 wherein the utilization device includes at least two drawers, the drawers being positioned with one of the drawers atop another of the drawers and wherein the feed tray is constructed and arranged to be positioned through the portal in one of the drawers so that another of the drawers can be accessed for loading with sheets.

15. A high speed sheet feeder as set forth in claim 14 wherein the portal is positioned on a lower of the at lest two drawers.

16. A method for interfacing a high speed sheet feeder with a host utilization device having a stack feed elevator platform accessed by a drawer, comprising the steps of:
defining a port in a front of the drawer of the utilization device;
positioning a feed tray through the port into the drawer proximate a utilization device singulator;
directing sheets from a sheet feeder stack to a second stack in the feed tray; and maintaining a predetermined second stack thickness by adding sheets from the sheet feeder stack to the second stack as sheets are removed from the second stack by the utilization device singulator.

17. A method as set forth in claim 16 further comprising directing sheets into the second stack to a side of the stack opposite a side engaging the utilization device singulator.

18. A method as set forth in claim 17 further comprising raising a stack feed elevator platform of the drawer to place the second stack of the tray into engagement with the utilization device singulator.

19. A method as set forth in claim 18 further comprising bending edges of the second stack into an angle substantially equal to an angle of sheets normally supported on the stack feed elevator platform.

29. A method as set forth in claim 19 wherein the step of bending includes engaging the edges with the utilization device singulator.

21. A method as set forth in claim 20 wherein the stack feed elevator platform includes a plurality of lead screws for raising and lowering the stack feed elevator platform and wherein the step of defining a port includes lowering respective tops of lead screws proximate the door front so that the tray can pass thereover, the step of lowering including supporting bases of the screws in bearings positioned below the level of a base of the drawer.

22. A method as set forth in claim 16 further comprising maintaining a predetermined second stack thickness, the step for maintaining including sensing the thickness of the stack and adding additional sheets to the stack when the thickness is less than the predetermined thickness.