US2240818A - Sheet-feeding mechanism - Google Patents

Description

May 6, 1941. B. WALE SHEET FEEDING MECHANISM Filed Aug. 2, 1939 4'Sheecs-Sheet 1 INVENTOR Bruce Wale 721.15 ATTORNEY May 6, 1941. w 2,240,818

SHEET FEEDING MECHANISM v Filed Agg. 2, 1939 4 Sheets-Sheet 2 his ATTORNEY 0 I May a, 1941. B. WALE SHEET FEEDINGMBCHANISM Filed Aug. 2, 1939 4 Sheets-Sheet 3 s H mm M H vm 0 N. a #w 3 Brace 7%[6 R m m M an. v 4 x .3 M M V o o Wm 3 n Nw MQ on. E a h. 8w v O 2* w g s M .ow bu or wr 2 mm Q hi0 ATTORNEY May 6, 1941. aw/ma SHEET FEEDING MECHANISM Filed Aug. 2, 1939 4 Sheets-Shet 4 r v ,1 vowooooo oooooo oe oovoooooooooooooo m2 m! w: 4 1 NW 0000 n o oooooooomoooooooooooooo .J I H m WW OOOOOO OOOOOOOOOOOOOO OOOO INVENTOR Brace m ATTORNEY ing shownin' section.

Patented May 6, 1941 shear-resume MECHANISM Bruce Wale, Berkeley, Calif. AppllcationAugnst z, 1939. Serial No. 281,851

came V (01. 271-26) [The invention relates to mechanism for consecutively. feeding sheets from a pile of the type for delivery to printing presses or. thefllike. h e One object of" the invention is .to 'provideiniprovedsheet-feeding mechanism which includes pneumatic devices for separating and finding several of the top sheets of' a pile, "co-ordinated suctionmeansfor lifting successivesheet's infthe path of the pneumatic'means, and means for advancing the sheets in succession.

Another object of the invention isto provide improved feed mechanism which includes means for acting on therear end portionsof thesheets "so that longer periods are available for the functioning of the feed, mechanism than when the sheets are separated from the pile at their front ends.

Another ob ect tr the inventi n is'to provide improvedmeans for maintaining the top of the stack ofsheets in a substantially constant rela- .tion to the feed mechanism.

Another object of the invention is to provide improved feed mechanismwhich includes means for readily timing the several pneumatic devices which act upon the sheets.

The invention is exemplified in mechanism comprising a pair of frame-sides c, c, in which are journaled a pair of co-acting upper andlower wheels b, b for delivering the sheets from the mechanism to the press, as well understood in the art. A sprocket chain p driven from the press, drives a sprocket 9 which is fixed to the shaft b -of the lower feedroll b Gearsb fixed to shafts byb, respectively, drive the upper feed roll-b from shaft b. The supportin structure also comprises a pair of' standards d, dfwhich are respectively connected to frame-sidesc, c by tubular frame members d, d. A shaft e extends through and is j'ournaled in, frame-sides c,c anda shaft e extends'through and is jourrlaled in standards-d, d A pair of sprocket wheels e are fixed to each of the shafts e, e and a table or. platform I for supporting the pile of sheets is carried by bars I carried by sprocket- Another object of the invention is to provide feed mechanism which includes suction-means operating to lift successive sheets vertically and means in addition, thereto for advancing the lifted "sheets laterally to the press.

Another object of the invention is to provide improved sheet-feeding mechanism which is adapted to be readily adjusted for feeding shee of different lengths and widths.

. Other objects of the invention will appear from the detailed description.

' The invention consistsin the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof. V l r U 1 1 Inthe drawings: p a V Fig. 1 is an elevation of the operatorisj sideof the machine embodying the invention; parts be- Fig, 1' is a detail of the ratchetdevicefc'r intermittentlyfadvancing the belts for moving the sheets longitudinally. I p i p Fig.--2is an elevation of the sideoffthe feed mechanism opposite thejoperator's side."

Fig. 2' is a detail of the "detent for controlling supporting table. 7 I

Fig. 3 is a central longitudinal section.

*4 is afplan, parts being broken-away for r illustrative purposes.

chains o which are operable by said sprockets to raise and lower the table to keep the top of the stack of sheets in predetermined relation to the. feedmechanism which is disposed above the table. Chains e are synchronously driven by gear O which is fixed to shaftc, a gear a meshing with gear I, a sprocket-wheel e" rotatable with gear e a sprocket-chain e driven by sprockets and a similar sprocket on the shaft e of sprocket e Shaft e is driv'en to elevate table f by a pinion II which is fixed to a cross-shaft ii and meshes with a gear 0 which is'flxed to one end of shaft e.

A removable hand-crank I! (Fig. 4) is' fixed to the end of shaft ii at the outside of frame-side c for manual rotation of shaft ii to, drive pinion II and gear. l and shaft e to'raise or lower the sheet-supporting table I to position thetopmost sheet of the stack into desired vertical relation with respect to the feed-mechanism.

The mechanism for liftingthe'sheets singly from the stack on table into the bite of the feed rolls b, b is mounted on, and carried by, a rectangular frame composed of transverse bars .19 "and II rigidly connected at their opposite ends by side-members I5 and 16. FramebarsBI.

which are. transversely spaced apart near the transverse center of the machine, are securedto frame-members runs form guides'for the sides [of the lifting-shoe frame hereinafter described.

the operation of the pawl forlifting the sheet- This frame carries the pneumatic devices 'ofithe sheet-feeding mechanismand is slidably adjustable ontubular frame members d, d to position the pneumatic devices for acting upon the rear ends of sheets; of diiferent lengths, the front ends of which heat a vertical stationary wall I.

"Bidemembers 1!, It are provided with, forked supporting legs which straddle tubular frame members d d". A cap plate 11 provided with screws 18 is secured to the lower end of frame into different positions for acting upon sheets of different lengths. One feature of the present in-.

vention is to have the lifting devices act upon the trailing end-portions of the sheets and this adjustment permits said devices to be adjusted for acting upon the trailing ends of sheets of different lengths.

A control finger I is positioned to engage the top of the stack of sheets. Mechanism for shifting finger -l2l, into and out of engagement .with the top sheet .of the stack to alternately hold and release ,the sheets comprises a shaft I20 to which finger I2l is fixed and which is journaled in bearings I23 carried by frame-bar 85; an arm I21 fixed to shaft I20; a connecting rod 24, one end of which is pivotally and adjustably connected to arm I21; an arm l4 pivotally supported on shaft H; and a cam-38 fixed to and-driven by a cross shaft 31 and adapted to engage an abutmentroller 22 mounted on arm I.- Arm u is adapted to oscillate flnger m to cause it to alternately engageand release the top sheet of the stack on table f. Shaft 31, which operates cam 38,; is driven by suitable gearing from; the press so it will revolve once for each H printing operation or revolution of the press cylinder. A spring, 23 is applied to retract arm I toward cam 38. Arm I4 is also adaptedto raise the sheet-supporting tablef by means of a pawl 15 which is pivoted to said arm and is adapted [to engageandzintermittently rotate a ratchetwheel l5 which is on shaft H between arm I4 and pinion l3.v Ratchet I 5 is fixed to pinion l3 which, meshes with gear 8 on shaft 0 which, through sprockets e and chains 0 isadapted toiraise the table f. A spring-pressed dog 26,

pivoted at .21, prevents backward rotation of ratchet l5.. The length of the retractile strokes of arm I are controlled, and are variable by the downward pivotal movement of finger l2l so that the table f will not be lifted unless the height of the pile has been lowered sufliciently to make it necessary tolift table 7 and so that the tablelifting mechanism will be lifted responsively' and; accordingly to the thickness of the sheets to maintain the desired operative relation between the'top of the stack and: the feed-mechanism.

' For this purpose, pawl I6 is provided with a and an arm 30 is keyed to the opposite end of shaft 29. A stop-screw 32 is threaded to a lug 83 on frame side c and a'spring 34 normally holds arm 80 against stop screw 32. A lock-nut 35 is provided for screw 32. By adjusting screw 82 contact arm 35 can be set to vary the operation ofthe table I- by arm 14 to maintain the height of the stack substantially at a constant level for reliable feeding of successive sheets 0 different materials or thickness.

The mechanism for lifting sheets consecutively from the stack on table I comprisesa vertically reciprocablev shoe or suction plate H2 which is provided'lwith' inlet ports H 4, .under which pass the perforated belts 51, the suction being operative on the topmost sheet of the stackthrough the perforations 58 in said belts. The suction- ,shoei I2 is integrally formed with a frame H0 which ismounted to slide vertically between frame- members 19, 80 and frame-bars 8|. Two guide-rollers H6 are carried by the shoe H2 at the rear. thereof and two guide-rollers Hfi lare carried at the front of said shoe. These rollers "guide and deflect a portion of the lower reaches of. belts 51: to insure the engagement of their upper faces with the bottom face of shoe H2 and raise and lower said reaches with the shoe.

.The bottom of the shoe is provided with a pair of; inlet ports H4 adjacent its rear which com- H5,at the front of the shoe H2. Each port H5 is connected by a fiexible'pipe 81 to the tube 85 which is journaled in frame-members 16' and 81.

"The outer end of pipe 85 is connected to a T- notch which, when the pawl is lifted by a tooth- I on ratchet-wheel l5 during the retraction of the pawl, will be engaged by a tooth IS on a latch {20 which is pivotally. supported at 2] on and -oscillates with arm ll Latch '28" wfll then hold [pawl 15 disengaged fromwheel I 5. While the top of"the stackis within .proper'range of the stack, ,finger l2l will. swing downwardly sumciently to permita longer stroke of arm I4. A

latch-controllingarm 35 is fixed to shaft 28 to trip latch 20. Wheniinger l2! permits a sumcient retractile stroke of arm H, the upperend of arm 35 will engage latch 20 to release pawl fitting 88 which is connected to the suction side jof. an air-pump. An adjustable valve 89 is provided on the top of fitting'88 to regulate the degree, of suction applied to the pipe 88 and the ports in the shoe H2. The inner end of pipe. 85 s d- ,1

,The, mechanism for vertically reciprocating frame H0 to raise and lower suction-shoe H2 into and out of engagement with the topmost sheet comprisesa pinion 82 fixed to pipe 85 and meshing with gear-teeth on the inner face of one side of I frame H0, a gear 83 rotatably mounted on a pipe 88 and meshing with gear 83 and gear-teeth on theinner face of 1 the opposite side of frame H0, an arm 90 fixed to pipe 85, a rod ll having one of .its ends adjustably andpivotally connected toarm 80, and a crank 5 38 to which rod M is pivotally connected. Crank 301s flxedto rotate with the driven shaft 31 and is driven one revolution for eachsheet-feeding operation. Shaft 31 is driven by apinion 48 fixed to shaft b and a .gear 46 fixed to shaft 31. This mechanism raises and lowers the pneumatic shoe'H2 and frame Hi! to intermittently bring the belts 51 into contact with the topmost sheet so thatthe latter will be subjected to suction through perforations 58 in said belts from ports H4 and H5 in the shoe.

The means for successively advancing the sheets lifted off the stack on table f comprises a pair of perforated belts 51, a pair of drivewheels 56 for said belts, a cross' -shaft52 to which wheels 53ar'e fixed, a pair ofidlerwheels 53 for belts 51 and a shaft 88 on whichpulleys 53 are end of an arm 3i which, is pivotally supported on tubular cross-member 62;" A counterweight= 65is adjustably connected to arm 3i, to shift shaft 58 reaches of the belts with shoe' iil. The lower reaches of belts 51 contact the uppermost sheet of the stack and are operated intermittently supported. Shaft 6Ii'is', supported in "the upper and pulleys 59 to keep the perforated belts" 'I taut and permit vertical movement of i the lower after the shoe has'been lifted to successivelyadvance thesheets into the bitefof rolls b, b by mechanism operated from shaft 31, which drives cam and is operated one revolution'for each feeding operation, This mechanism comprises .a crank 43 fixed to oneiend of shaft 31; a link 45 pivoted to crank 43, a collar" held onand rotatably mounted on shaft 52 of belt-pulleys 53, a pawl 43 pivoted to collar "41 and a ratchetwheel 53 fixed to shaft 52. Adog 54 pivotedfto frame-side c preventsreverse rotation -of ratchet-wheel 53 and shaft 52. During each op- 1 er'ationfof the presscylinder; an operative stroke in timed relation to the lifting mechanism will be imparted to' belts 51 to advance the lifted sheet held by suction in shoe III-over aguide "'I33 andinto the bite of rolls b, b in timed i-ela- 'tionwith the press, as well understoodin the art.

The feedmeans comprises a pair of blast-delivery pipes ornozzles'; I 33' for flumng the side edges side o'f'a pump is delivered through a' pipe 33 into a casing 95. Said casing is connected to and supported by pipe 83 which is fixedly supported in frame-member I3 and one of the frame-bars 3I Flexible pipes 31 connect nozzles I33 to the chamber in casing to deliver air under pressure to said nozzles. i i

A pair of blast-nozzles I33 are mounted in brackets I3I which are adjustably mounted and transversely adjustable on frame-bar I9. The

lower ends of these nozzles are turnedinwardly toward the side-edges of the uppermost sheets of the stack on table 1 and are adapted to fluff the adjacent marginal portions of the uppermost sheets on the stack when blasts of air are discharged from the nozzles. Paper-guides I34'are secured on brackets I3I so that thenozzles I33 and said guides are transversely adjustable for different widths of sheets. i A nozzle II! is adjustably supported on the frame-bar and its lower end extends forwardly to delivera blast of air longitudinallyunder the lifted sheetfrom its rear edge toits front edge to elevate the portion of the sheet forwardly of .shoe II2 with the suction-lifted trailing portion of the sheet; a v n I Valve-means is provided for controlling the blasts from nozzles I33, I", toalternately deliver the blasts of air to said nozzlesr Air under pressure from the pressure side of a pump is d8? livered through a pipe 36 into a casing 35 which is connected to, and supported by; pipe 88, which Els fixedly supported in frame-member ll and'one of the 'frame-barsll. i

nozzles I33 tothe chamber in valve-casing 35 to Flexible pipes 31 connect deliver air under pressure to said nozzles, A

fis operatedby arm "I4. .Arm I25 rocks I 33 on the pivot-shaft of valve'98.

actor of thesheets. 3! can be revolved to a position where suctionpipe 88 to nozzle III. A valve "is pivotally supported in casing35 and is adapted to alternately cutoff the su'pply of air to pipe 86, pipe 34 and nozzle-lil while air is delivered through pipes 91 'to nozzles I33" and to deflect the supply of air from nozzles I33 while permitting it to pass through pipes 33, 94 tonozzle III. This valve is operated intimed relation with the feed mechanism byan arm I 25"fixed toshaft- I23 which carries the height-limiting fin'ger I2I and an arm In setting up themachine for-arun, a stack -of sheets is placed'ontable fwith thefront of the stack adjacent guide-wall I38. The feedmechanism frame is then adjustedalong framen'iembers d 11 so that shoe "I I2 will be disposed over the rear of the st'ackand guides I36 and nozzle II! will belocated. at the rear edge of the stack. The --feed-mechanism frame will then be locked in positionby screws I8. The adjustable connectionsbetween rod 4i and arm "and betweenrod 24 and arm'IZ'I permit thisadjustment without variation in the timingof the operation or: the suction-shoe lifting mechanism and the mechanism for operating valve '98. Upon moving lever arms 38,:121 .to a position'in line with setting-up locations'lndicated on the side of "frame member", thumb screws 33, I33 will be tightened to render said rods operative in their adjusted positions. Brackets I3I will be adjusted transversely to position side-guides I34 at the sides of the stack and'to position nozzles I33 to deliver blaststo the sides of the upper sheets of the stack. Screw 32 may be adjusted to alter the height of the top-of the pile relative to shoe -II2. The air-blast nozzles II'I, I33 will be adjusted vertically to deliver blasts at the desired levelt The air-pump will then be operated con-- tinuously to "supply air under pressureto casing 95 and apply suction .to therfltting 88; Nozzles I33 are set to fluifand raise the top several sheets of the stack approximately 4 inch and the blastof air is suflicient for-that purpose. Screw 32 is adjusted to'maintain the top of the stack 01351186158 in "desired relation to the feedmechanism'according toithe thickness or char- Crank-arm 39 on cam-shaft shoe I I2 and belts 51 against its bottom face will be lowered into the fluffed portion of the sheets. i

In operation, crank-arm33 in properly timed relation tothe press; will revolve and lower sue tion-shoel I2with belts 51 against its bottom face, onto the sheets which will be fluffed by blasts of air from nozzles I33. 'During downward. travel of shoe I I2, cam 38 raises control-finger I 2| from the contact. it has last made with the top sheet of the stack and valve 98 cuts off air to nozzle H1 and permits air to flow to nozzles I33. During the lowerv portion of this downward movement of shoe H2 and belts 51, crank-arm 43 is revolving on its idlestroke so that belts 5'I arenot advanced. Idler pulleys 53 hold the belts 51 taut to permit the vertical movement-of the lower reaches of said belts with shoe II2. Suction is constantly appliedthrough perforations 58 in the belt and inlets H4 in the shoe sothat the top sheet, when the shoe H2 is lowered, will adhere j to the belts and' be lifted upwardly therewith.

When arm 33, in its rotation, has lifted shoe II2 and belts'5lsufllciently to raise the sheet just above level of the blast from nozzle III, cam 38 will rock arm I25 to lift lever 33 and shift valve flexible pipe 34 is connected to deliver air from for-a strongquick blast directedforwardly under the lifted sheet. This blast of air will raise the entire central area of the lifted sheet into clingthe lower reaches of belts 51 (Fig. 3) The sheet ing contactwith the ,entire forward length of 4 -is thus lifted above guide I39 and advanced to 1 :rollers b, b under powerderived from crank 43 i'which, at this moment, :is positioned where arm 10.

45 is operating collar "and pawl 49 and advanca ing ratchet-wheel 53 to'turn shaft 52 and drive pulleys 56 and belts 51. At this timethe cam 38 has revolved to such an extent that controlfinger, l2l will be loweredsufiiciently to prevent a any possible displacementof the position of the several'top sheets'bythe feeding action of belts 51. As-the'lower reaches of belts 5! advance over ports II 4, suction is first applied to thesheet gfromsuccessive holes 58. When the-trailing-end of the sheet passes beyond the-rangeof therear pair of holes I I4, air enters said holes. By reason i of the arrangement described with. respect to tubes: 81, such entry of air; does notinterfere with the'sufliciency of the front air holes IILto 7 2,240,818 98 to deflect the blast from nozzles I33 and direct a stream of air momentarily through nozzle II! the press. The invention also exemplifies feeding mechanism; which operates on the trailing ends- 0f thesheets to successively. separate them .from the, stack and advance them to the press.

The invention also exemplifies lifting mechanism and associated pneumatic means for fiufiing the sides of the sheets to aidin the separation of the uppermost sheet fromthe remainder of the stack.

'I'heinvention also exemplifies means for delivering a blast of air from the rear to the front of the sheets to separate the uppermostsheet from the remainder of the stack during the lifting and advancing .of the uppermost sheet. .The invention also exemplifies feed mechanism which, is readily adjustablefor gsheets of different sizes and efiicient and rapid in operation.

' The inventionjis not to be understoodas re- ;stricted to the details set forth, since these may be modified within the. scope of the; appended claims; without departing from thespirit and scope of the invention.

Having thus described the invention, what I claim as ,new and desire to secure, by Letters Patent. is: a

continue to hold the sheet until its feed is completed and-the trailing end of the'sheet passes beyond range of the shoe I-I2. During this advancing action, cam 38 is revolved to permit arm I4 to swing toward the low :portion of .cam 38 and if sufiicient sheets .have b'een fedfromthe 'zpile, control finger I2I will drop sufiiciently to release pawl I6 for-engagementwith ratchet I5 and, upon further rotation, the high surface of cam '38 will cause shaft e to rotate and raise table I .and the stackof sheets thereon. The elements ofvthe feed-mechanism are. timed and ,co-ordinated so that nozzles l 33 will fluff the uppermost i sheets of the stack while thexsuction-shoe H2 and'frame I III are being lowered -to.causerbelts 51 to engage the uppermostsheet. During this :period, theair entering the suction-shoe II! will pass to the suction side of the air-pump so that the blast-from the pressure side will be sum- "ciently high pressure to cause the air from nozzles -I33 t0 fluff the sheets at their, sides..

When belts SLandthe suction-shoe I I2 are low- -ered so that the topmost sheet closes. the perforations 58 inthe belts; the pressure of the air "from. the pump will beautomatically reduced to cause the sheets below the one held by the belts to drop away, therefrom. During the' up-stroke of" shoe. H2 and belts 51 withthe sheetheld thereby, valve 98 will be operated todefiect the remaining blast fromvnozzles I33 anddeliver a blast throughnozzle 'l H at the rear of the sheet. *This blast will pass underthe suspended sheet and cause the frontportion of the sheet to be lifted with the shoe; The-nozzles I33 are disposed to separate or' fluff only the rear portion of a I I the sheets so that during the engagement of height-control finger-I2I with the top sheet of the: stack, the front portion -of the sheets may remain together. ":JTheZtimed blast from the I 5 nozzle IIz-I causes the portion of the sheet ahead :of the'shoe H2 to be separated from thestack as the shoe is raisedpreparatory to the advance of the sheet by the'inter nittent operations of belts 51 which will deliver the front edge of the sheet to, the rollers b, b

, :The invention exemplifies suction-controlle a lifting means, such as shoe Iilwhich is movable in a vertical path to separate the uppermost sheet from'the stack and means, 'such as perforated belts, for advancing the lifted sheets to .1. In sheetfeeding mechanism for printing pressesand the like, the combination of means for supporting a stack of sheets, vertically movable suction-means for successively lifting the sheets verticallyfrom the stack, and intermittent means for successively advancing the sheetshorh .zontally beyondthe suction-means, said inter mittent means comprising apart movable vertically with the suction-means.

2. In sheet feeding mechanism for: printing presses and the like, the combination-of means for supporting a stack of sheets, vertically movablefsuction-means for successively lifting the sheets-vertically from the stack, and'intermit- 40: tent means forsuccessively advancing the sheets "by, andbeyondthe suction-means, said interhorizontally relatively to, and while they are held mittent means comprising a part movable vertically-with the suction-means.v I

w3. In sheet feeding mechanism for printing presses and the like, the combination of means for supporting a stack of sheets, a vertically movable suction-shoe for intermittently and successively lifting the sheets from the stack, and means for successively advancing the sheets horizontally past and ,while held by the shoe comprising a, part-movable vertically with the suctionmeans.-- 7

4. In sheet feeding mechanism for printing presses and the like, the combination of means for supporting a stack of sheets, vertically movable sheet-lifting means engageable only with the trailing portions of the sheets, and means for consecutively advancingthe lifted sheets, comprising a part movable vertically with the lifting-means. 5. In, sheet feeding mechanism for printing presses and the like, the combination of means forisupportingua stack of sheets, vertically movable suction-operable sheet-lifting means engageable only with the trailing portions of the sheets. and means for consecutively advancing the lifted sheets comprising an endlessbelt havinga portion thereof movable vertically of the lifting-means.

v 6. In sheetfeeding mechanism for printing 70.

presses and the like, th combination vof means for supporting a stack of sheets, vertically movable sheet-lifting means engageable only with the trailing portions of the sheets, means for consecutively advancing the lifted sheets, comprising a belt having a portion thereof movable with blast r air under thesheets to lift 'thejfrontportions of the sheet while they-are being advanced.

,under the shoe, ,means for guiding the belts across the lowerlf face ofthe shoe, means for ntermittentiyoperating the belts to advance the f siieetsfwhile helclby thesuction-shoe, and means the lifting-means and mean for delivering a 1 '7. In sheet, feeding mechanismfor; printing presses and thelike, the combination of means for supporting a stack of sheets, means for lifting and, advancing sheets from the stack, and

means foraltern ately delivering a blast of air to one of the side-edges of the sheets and deliveringa blast to the trailing edges of the sheets.

8. In sheet feeding mechanism for-printing presses and the like, the combination of means for supporting a stack of sheets, suction-operable lifting means for the sheets, an endless perforated belt for advancing the lifted sheets, a portion of said belt being movable vertically by the lifting means, and mechanism for intermittently operating the lifting means and the belt to successively lift and advance the sheets consecutively from the stack. a

9. In sheet feeding mechanism for printing presses and the like, the combination of means for supporting a stack of sheets, a suction-shoe for lifting the sheets provided with inlets in advance of one another, an endless perforated belt for advancing'the lifted sheets, a portion of said belt being movable vertically by the shoe, and

mechanism for intermittently lifting the shoe and nlountedlon said frame for delivering blasts of air totne edges'jiofthesheet. v H 14, In" sheet-feedingmechanism for printing presses and the like,the combination. of a rectinnearly and vertically movable suction-shoe for snii'ting sheets vertically from a level-controlled pile, and anintermittently operated endless belt ror successively advancing the sheets horizontally, having a portion thereof guided across tne shoe and movable vertically therewith.

15. In sheet-feeding mechanism for printing presses and the like, the combination of means 101' supporting a stack of sheets, means for intermittently engaging and lifting a transversely central portion of the top sheet, means for delivering a transverse blast of air to one sideedse of the sheets laterally of the lifting means 101 separating the side portion of the sheets and co-acting with the lifting means in separating "the top sheet, and means for intermittently advancing the lifted sheet.

:16, In sheet-feeding mechanism for printing presses and the like, the-combination of means 10]. supporting a stack of sheets, vertically movable suction means for intermittently engaging and lifting the transversely central portion of the top sheet, means movable vertically with the suction means for delivering a transverse blast or air to one side-edge of the sheets laterally of the lifting means for separating the side porsaid frame, an endless perforated belt extending under the shoe, means for guiding the belt across the lower face of the shoe, and means for intermittently operating the belt to advance the sheets while lifted by the suction-shoe.

11. In sheet feeding mechanism for printing presses and the like, the combination of means, for supporting a stack of sheets, lifting means comprising a frame, a suction-shoe slidable vertically in the frame and provided-with inlets in advance of one another, mechanism for raising and lowering the shoe in saidframe comprising a rotatable pipe connected to deliver air to the shoe, an andless perforated belt extending under the shoe, means for guiding the belt across the lower face of the shoe, and means for intermittently operating the belt to advance the'sheets while held by the suction-shoe.

1 2. In sheet feeding mechanism for printing non of the sheets and co-acting with the lifting means in separating the top sheet, and means I01 intermittently advancing the lifted sheet.

17. In sheet-feeding mechanism for printing presses and the like, the combination of means for supporting a stack of sheets, vertically movaole suction means for intermittently engaging and lifting the transversely central portion of the top sheet, means movable vertically with the suction means for delivering a transverse blast of air to each of the side-edges of the sheets laterally of the lifting means for separating the side portion of the sheetsand co-acting with the lifting means in separating the top sheet, and means for intermittently advancing the lifted sheet.

18.,In sheet-feeding mechanism for printing presses and the like, the combination of means for supporting a stack of sheets, means for presses and the like, the combination of for supporting a stack of sheets, lifting means comprising a frame, a suction-shoe slidable vertically in the frame and provided with inlets in advance of one another, mechanism for raising and lowering the shoe in said frame comprising a rotatable pipe connected to deliver intermittently engaging and lifting the transversely central portion of the top sheet, means for delivering a transverse blast of air to each 1 of the side-edges of thesheets toward the lifting air to the shoe and a pair of gears operable by ,I

said pipe, an endless perforated belt extending under the shoe, means for guiding the belt the lower face of the shoe, and means for intermittently operating the belt to advance the sheets while held by the suction-shoe.

13. In sheet feeding mechanism for. printing" presses and the like, the combination of means for supporting a stack of sheets, lifting means comprising a longitudinally adjustable frame, a

suction-shoe slidably mounted in the frame. mechanism for raising and lowering the shoe in said frame, endless perforated belts extending means for separating the side portion of the sheets and co-acting with'the lifting means in separating the top sheet, and means for intermittently advancing the lifted sheet.

19. In sheet-feeding mechanism for printing,

presses and the like, the combination of means for supporting a stack of sheets, means for intermittently engaging and lifting the transversely central portion of the top sheet, means for delivering a transverse blast of air to eachof the side-edges of the sheets toward the lifting means for separating the side portion of the sheets and co-acting with the lifting means in separating the top sheet, means for delivering a blast to-the trailing edge of the sheets after the lifting means has engaged the sheet, and

gears for intermittently advancing the lifted ee t V t v '20.In sheet-feeding I01: printih:

"presses andthe li ke ,the combination 10! means for. supporting a steel: oi sheets, a suction-shoe for intermittently ehsdzinz and lifting the transversely central portion ef'the top aheet. means for delivering i. transverse blast 0! lit to each side-edge oi the sheets lateraliy'of and injadvance of the engagement oi the shoe for separating the side portion of the sheets and assisting the lifting means in separating the top sheet, and means for intermittently advanc- 5 ing the liited'sheet.

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