US2761681A - Sheet feeding apparatus - Google Patents

Description

' 'Sept. 4, 1956 G. w. TEB'BS A 2,761,681

SHEET FEEDING APPARATUS Filed Jul 5, 1955 4 Sheets-Sheet 1 INVENTOR ATTORNEY Sept. 4, 1956 s. -w. TEBBS SHEET FEEDING APPARATUS Filed July 3, 1953' 4 Sheeis-Sheet 2 FT n"! INVENTOR.

fiw M41540 7% BY 7 QTTOENEY Sept. 4, 1956 G. w. TEBBS SHEET FEEDING APPARATUS 4 Sheets-Sheet 3 Filed July 5, 1953 E7 I INVENTOR. (9W /Aum JAM 00% Q. [3am HTTOENEY Sept. 4, 1956 G. w. TEBBS 2,761,681

' SHEET FEEDING APPARATUS Filed July 5, 195:5 4 Shee ts-Sheet 4 & INVENTOR.

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HTTOENEY United States Patent SHEET FEEDING APPARATUS George WilliamTehbs, Walthamstow, London, England, ass'ignor to Headley Townsend Backhouse, Nassau, Bahamas Application July 3, 1953,1Serial No. 365,902

Claims priority,.applicafionGreat Britain 'July 9, 1952 25 Claims. ((1271-62) This invention relates to sheet feedersfor feeding sheets of paper, cardboard, and other materials of a similar character, to printing presses and various other machines for acting on .such sheets.

The present invention is of the nature of an improvement in the sheet feeder described ,and claimed in my copending application .Serial No. 348,313, filed ,April 13, 1953. The sheet feeder shown and describedin said copending application is particularly adapted for feeding sheets one after another from a stationary upright pile thereof, and comprises sheet separating mechanisms operable .to separate a transverse edge portion of each sheet in turnfrom the top of said pile, and a cooperating conveyor for removing .from the pile the sheets so separated by said separating mechanisms. For this purpose, the sheet separating mechanisms are arranged for vertical up and down movement, and are intermittently lowered by controlled power means during feeding of the sheets from the pile so as to necessarily maintain said separating mechanisms in proper operating relationship with respect to the top of the diminishing pile and thereby enable continued separation and feeding of the sheets therefrom. When all or substantially .all of the sheets have been .fed and the pile is exhausted or substantially so, the sheet separating mechanisms are capable of being raised .to the top of the feeder so as to enable loading of ,a new pile of sheets in feeding position, whereupon thefeedingof sheets may be resumed from the newpile.

The sheet separating mechanisms areso driven that during downward movement thereof, as well as during upward movement thereof, the cyclic timing of said sheet separating mechanisms with respect to the cycle of movement of the conveyor is maintained. This is achieved by automatically advancing .the timing of thesheet separating mechanisms as the latter descends and by retarding said timing as said mechanisms are raised.

From the above brief description of the construction and operation of .the sheet feeder disclosed in ,the aforementioned copending application, it will be apparent that the sheet feeder must be stopped or 'the sheet feeding operation thereof must be interrupted when it is necessary to reload the feeder with .a new pile of sheets and while said new pile is being loaded "in feeding position. This stoppage or interruption for reloading purposes occurs frequently during an entire .run, particularly when the feeder is operated at ahigh rate of speedand/ or when relatively thick sheets are being handled. These stoppages or interruptions known as down-time add up at the end of a normal day and result in a material decrease in the hourly output rate of fed sheets. Additionally, each time the feeder or the feeding operation thereof is stopped for reloading purposes, the continuous procession of sheets to the machine being fed is interrupted.

It is accordingly one object of the present invention to improve the above described sheet feeder and sheet feeders of this character so that the same can be reloaded with sheets without having .to stop the feeder :and without 2,761,681 Patented Sept. 4, 1956 interrupting the feeding of sheets therefrom to the machine being fed thereby.

Another object of the invention is to provide a sheet feeder of the above character which is capable of feeding sheets substantially continuously from the top of a stationary upright pile thereof through addition of sheets to the bottom of said pile during the feeding operation.

Another object is to provide in a sheet feeder of the above character and in association with the vertically movable sheet separating mechanisms thereof novel pile supporting and lifting means which enables lifting in unison with said sheet separating mechanisms the remainder of a pile of sheets to a higher elevation while the sheets are being fed from said pile, so that a new pile of sheets may be .loaded in feeding position below the elevated pile while the feeding of sheets from said elevated pile continues.

Another object is to provide in a sheet feeder having a vertically movable sheet separating mechanism for separating sheets in succession from the top of a normallystationary upright pile thereof, a vertically movable pile support, and means for connecting said pile support with said sheet separating mechanism, whereby said pile before it is completely exhausted may be raised by said sheet separating mechanism to a higher elevation while the sheets are being fed therefrom, so that a new pile of sheets may be loaded in the position vacated by the preceding pile While the feeding of sheets from said preceding pile continues, said support and pilethereon being releasably held in elevated position and movable downwardly relative to the sheet separating mechanism to deposit theremainder of the preceding pile on top of said new pile, and said connecting means providing for said downward movement of said pile support and for downward movement of the sheet separating mechanism relative to said .support as the feeding of sheets from the preceding pile continues.

The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.

.In the drawings wherein like reference characters refer to like parts throughout the several views,

Fig. l-is a perspective view of the sheet feeder forming the subject matter of the aforementioned copending application Serial No. 348,313; V

Fig. 2 is an enlarged fragmentary side elevational view of said sheet feeder looking :from the left of Fig. 1 and embodying temporary pile supporting and lifting means constructed, arranged and operated in accordance with the present invention;

.Fig. 3 is a .rear-elevational view of the structure shown in Fig. 2;

Fig. 4 .,-is a side elevational view of the lower part of said sheet feeder, showing an alternate rail arrangement on which piles of :sheets may be .loaded or made up and run into feeding position to load and reload the feeder;

.Fig. 5 is aside view, partly in section, showing an alternative construction for temporarily connecting the pile support to the sheet-separating mechanism; and

Fig. 6 is a section on the line 66 in Fig. 5.

The present invention ,is illustrated in the drawings as embodied, for example, in .the sheet feeder disclosed in the copending application above referred to. Only such portions of the sheet feeder as are necessary to a complete understanding of the invention are herein illustrated and, for convenience, have been given the same reference characters as in the copending application referred to.

The sheet .feeder disclosed in the aforementioned copending applieation and herein illustrated in Fig. l of the drawings, is adapted for feeding sheets of paper, card stock, or the like, from the top of a stationary upright pile 26 thereof to a forwardly extending tape conveyor 21 in a manner such that the sheets are conveyed in the form of a stream of underlapped sheets to a printing or other machine for operating on the individual sheets of said stream. The pile of sheets 20 is supported in feeding position on a loading skid 20a which rests on the machine foundation.

The sheet feeder comprises four uprights 22, 23, 24 and 25 secured to pairs of top and bottom brackets 26 and 27, respectively, said top brackets being interconnected by crossbars 28, 29 and 30, said bottom brackets being interconnected by a crossbar 31, and the uprights 23 and 25 being formed with rack teeth 98 and 99, respectively, on and along the major portion of the rear edges thereof. Guided on the uprights 22 to 25 for straight-line vertical movement downwardly and upwardly is a sheet separator carriage comprising guide blocks 35 and 36 interconnected by tubular crossbars 37 and 38. Supported on the separator carriage for vertical movement therewith are two similar sheet separating mechanisms 39 which are disposed at opposite sides of the pile of sheets 20, the righthand mechanism only appearing in Fig. l, the left-hand mechanism being shown in Fig. 2. The sheet separating mechanisms 39 include timed combing wheels 127 for buckling the opposite front corner portions of the top sheet on the pile 20, and timed suction devices 140 for lifting said sheet at the buckled corner portions thereof and stretching the same in a direction transversely to the feeding direction whereby the entire front edge portion of the separated top sheet is straightened and raised to a predetermined level above the top of the pile 20. A de tailed disclosure and description of the sheet separating mechanisms 39 may be had, if desired, by reference to the aforementioned copending application.

The sheet feeder also comprises an upright conveyor for taking each separated sheet from the suction devices 140 and removing said sheet from the pile in an upward direction and in underlapped relation with a preceding separated and removed sheet, said conveyor being disposed between the sheet separating mechanisms 39 and forwardly of and in close proximity to the stationary pile of sheets 20. The upright conveyor comprises at least two transversely spaced units 45 and 46 carried by the crossbars 29 and 31, each unit comprising an endless chain 150 and a series of sheet grippers 151 which are carried by and equally spaced apart along said chain, the spacing between the grippers being less than the length of the shortest sheet which the feeder is designed to handle. Suitable cam means are provided along the path of travel of the grippers 151 for successively operating the latter to grip the separated front edge portions of successive sheets and to release said sheets for transfer to the tape conveyor 21, said cam means including cam units 40 and 41 which are mounted on and movable with the sheet separator carriage and control the operation of the grippers 151 in timed relation with the operation of the sheet separating mechanisms 39 as said grippers travel past the top of the pile of sheets 20. The upright conveyor units 45, 46 include upright pile positioning bars or guides 193 against which the pile of sheets 20 is loaded in accurate feeding position. A detailed disclosure and description of the upright conveyor may be had, if desired, by reference to the aforementioned copending application.

As disclosed and described in detail in the aforementioned copending application, suitable driving means are provided for continuously driving the endless chains 150 at a surface speed such that for each cycle of operation of the feeder said chains will be advanced a distance equal to the spacing between successive grippers 151. The sheet separating mechanisms 39 are operated in timed relation with the cycle of movement of the conveyor chains 150 by suitable driving means including an endless chain 57 which is driven continuously in the same direction and at the same surface speed as that of the conveyor chains 150. The chain 57 passes around and drives a sprocket 65 which is fixed on one end of a transversely extending drive shaft 66 to rotate the latter one complete revolution for each cycle of operation of the feeder, said shaft being rotatably carried by the separator carriage and being drivably connected to suitable mechanisms for rotating the combing wheels 127 and operating the same toward and away from the top of the pile 20, and for operating the suction devices 140 toward and away from said pile in timed relation with the operations of said combing wheels. Because of the described drive comprising the chain 57 and sprockets 65, the sheet separating mechanisms 39 will be operated in all vertical positions thereof and in timed relation with the cycle of movement of the conveyor chains 150 at each and every position that they may occupy within the range of vertical movement thereof. This is accomplished through the rolling action of the sprocket 65 downwardly along the chain 57 as the sheet separating mechanisms descend, which action advances the timing of said mechanisms a degree commensurate with the extent of downward movement thereof, and through the rolling action of said sprocket upwardly along said chain as the sheet separating mechanisms are raised, which action retards the timing of said mechanisms a degree commensurate with the extent of upward movement thereof. Thus, the timing of the sheet separating mechanisms will be advanced or retarded relative to the cycle of movement of the upright conveyor depending on the vertical position of said mechanisms, and regardless of what position said mechanisms occupy vertically or the direction of vertical movement thereof the timing relationship between the sheet separating mechanisms and the upright conveyor will be maintained.

When the sheet separating mechanisms 39 operate initially on the top of a pile 20 of maximum height which the feeder is designed to handle, said mechanisms are located a short distance below the top of the upright conveyor. This location of the sheet separating mechanisms is substantially represented by the broken line showing thereof in Fig. 20f the drawings. As the sheets are separated and fed successively from the top of the stationary pile 20 during the normal operation of the feeder, the separator carriage and the sheet separating mechanisms 39 thereon are lowered at certain intervals with the change in the level of the diminishing pile to enable continued separation and feeding of sheets from said pile. This lowering of the separator carriage and sheet separating mechanisms is effected by power means carried by said carriage and operated from the driven shaft 66 under the control of a feeler 70 which is also carried by the separator carriage and actuated into and out of engagement with the top of the pile 20 once during each feeding cycle, all as disclosed and described in the aforementioned copending application to which reference may be had for a more detailed disclosure and description thereof. Briefly, the power means for lowering the separator carriage and the sheet separating mechanisms 39 comprises a feeler controlled, pawl actuated ratchet which is splined to and slidable along an upright shaft 87 rotatably mounted at its opposite ends on the adjacent frame brackets 26 and 27. Splined to and slidable along the shaft 87 is a worm 93 which meshes with a worm gear 94 fixed on a cross shaft 95 rotatably carried by the separator carriage and having fixed thereon spur pinions 96 and 97 which mesh with the rack teeth 98 and 99, respectively, on the uprights 23 and 25, respectively. Rotation of the shaft 87 by the ratchet 90' will thus impart rotation to the shaft 95 through the worm 93 and worm gear 94 in the proper direction to lower the separator carriage and the sheet separating mechanisms 39, said worm and worm gear being self-locking to hold said carriage against sliding downward movement under the weight thereof. I

When all or substantially all of the sheets have been fed and the pile 20 is exhausted or substantially so and it is necessary to reload the feeder with a new pile of sheets, the separator carriage and the sheet separating mechanisms 39 thereon are raised to the top :of the feeder without disturbing the timing relationship between said mechanisms and the upright conveyor, as hereinbefore described. This raising of the separator carriage and the sheet separating mechanisms is accomplished, as disclosed and described in detail in the aforementioned copending application, through axial inward movement of a 'handwheel 103and rotation by said "handwheel of intermeshing bevel gears 100 and 101, the gear 100 being fixed on the upper end of the separator carriage operating shaft 87 and the gear 101 having clutching engagement with the hand-wheel. The inward movement of the handwheel 103 is utilized to release the ratchet 90 from the power operated mechanism and thereby enable rotation of shaft 87 by the handwheel to raise the separator carriage and the sheet separating mechanisms 39 thereon.

The present invention contemplates the provision of pile supporting and lifting means movable upwardly in unison with the separator carriage and the sheet separating mechanisms 39 thereon, whereby the normally stationary pile of sheets 20, when a major portion of the sheets have been fed therefrom and before said pile is completely exhausted, may be raised together with said carriage and mechanisms to the top of the feeder or to a selected level, so as to enable loading of a new pile of sheets in feeding position beneath the elevated remainder of the first pile. During upward movement of the remainder of the first pile and while the latter is in its elevated position and the new pile of sheets is being loaded beneath the same, the feeding of sheets from said first pile continues, and when said new pile 'has been so loaded the remainder :f the first pile is deposited on top .of the new pile, thus enabling the feeder to feed sheets substantially continuously from the top of a continuous supply of sheets. There is herein shown one form of pile supporting and 'lihting means constructed, arranged and operated as follows to accomplish this continuous feeding .of sheets by :the feeder and the replenishing of the sheet supply during the feeding operation.

To begin with, the usual skid type of pile support 20 is eliminated and in lieu thereof a plain pile board 300 is used (Figs. 2 and 3). The pile board 300 has secured to the underside thereof guiding and ,reenforcing cleats 301 which extend lengthwise of said board and are located inwardly of the :side edges of the board. The pile board 300 is placed on a stool :or platform 302 with the front edge thereof in contact with the front pile guides 193, and is located centrally of the feeder determined through abutting engagement of the ,cleats 301 with the adjacent sides of said stool which is also located centrally of the feeder and rests on the machine foundation. The sheets forming the initial, stationary, relatively high pile 20 are loaded on the pile board 300 with the front edges thereof in contact with the front pile guides 193 and with one of their side edges in contact with an upright side piling guide 303 which further serves to locate the pile centrally of the feeder. The pile guide 303 is removably and adjustably carried by the stool 302 and has a portion thereof slidably engaged in a suitable groove formed in the upper surface of said .stool. The pile board 300 is suitably slotted to receive the pile guide 303 and to permit lateral adjustment of said guide and movement of said board into and out of pile supporting position from the rear of the feeder.

Disposed below the separator carriage are 1W0 brackets 304 and 305 which are guided on the uprights .22, 23 and 24, 25, respectively, for straight-line vertical movement upwardly and downwardly. These brackets 304 and 305 are formed with relatively long rearwardly projecting arms 306, 306 having journalled thereon shafts 307, 307 which extend lengthwise of said arms. Firmly secured to opposite ends of each shaft 307 are latches 308 which are counterbalanced to swing inwardly toward the pile board 300 to an upwardly and inwardly inclined-position determined through engagement of lower portions of said latches with the respective arm 306, as shown in Fig. 3. Normally the stationary pile of sheets 20 is supported on the stool 302 at a predetermined distance up from the machine foundation, and while sheets are normally being fed from said pile so supported, the brackets 304, 305 rest on the base brackets 27 of the feeder with the arms 306 of the former brackets located below the 'plane of the upper surface of the stool 302 and with the latches 308 on said arms positioned below the pile board 300 and inwardly of the side edges thereof, as shown in Fig. 3, in readiness to lift said board and thepile of sheets thereon in a manner and by mechanism :to he presently described.

Extending transversely of the feeder :and journal-led in suitable bearings in the brackets 304 and 305 is a shaft 309 having fixed thereon :spur pinions 310 and 311 which mesh with the rack teeth 98 and 99, respectively, on the respective uprights 23 and 25. Disposed outwardly of the feed side bracket .305 and fixed on the adjacent end of the shaft 309 is a ratchet 312 which is normally continuously engaged by a pawl 313 pivotally mounted at 314 on the bracket 305. The ratchet .312 and pawl 313 cooperate to hold the brackets 304, 305 in any elevated position and to prevent rotation of the shaft 309 in the direction .to lower said brackets. The pawl 313 has secured thereto or formed integrally therewith a handle 315 for moving ;said pawl into and out of engagement with the ratchet .312, and which counterbalances the pawl and serves to bias the latter toward and into engagement with said ratchet. also fixed thereon outwardly of the ratchet 312 a handle 316 for rotating said shaft and the pinions 310, 311 thereon to raise and lower the brackets 304, .305. The bracket .305 is provided with suitable releasable springpressed latch means .317 for releasably holding the pawl .313 in ratchet releasing position when the brackets 304, 305 are lowered by the handle 316 from an elevated position to the bottom of the feeder.

Bolted or otherwise suitably secured to the outer surfaces of the brackets .304, 305 are vertically extending blocks 318 which are provided along the .rear edges thereof with downwardly facing :ratchet teeth 319. Carried by and movable vertically with the separator carriage are two pawls 320 which'are firmly secured to a shaft 321 which extends transversely of the feeder and is journalled in suitable hearings on the guide blocks 35 and 36 of the separator carriage. The pawls 320 are arranged to automatically engage the teeth 3.19 of the ratchet blocks 318 when the separator carriage has been lowered sufliciently to enable such engagement, as will be hereinafter described. The pawl 320 at the feed :side of the feeder has secured thereto or formed integrally therewith a handle 322 for swinging the pawls 320 into and out of operative positions with respect to the ratchet blocks 318, said handle counterbalancing said pawls and serving to bias the same into operative positions. The separator carriage is provided at the feed side of the feeder with suitable releasable spring-pressed latch means 323 for releasably holding the pawls 320 in their inoperative positions.

.As herein-before described, the separator carriage, during normal operation of the feeder and as sheets are fed successively from the top of the stationary pile 20 on the stool 302, is lowered step by step to maintain the sheet separating mechanisms 39 in operating position with .respect to the height of the diminishing pile and enable continued separation and feeding of sheets from said pile. It will thus be apparent that when the separator carriage in the downward movement thereof approaches the brackets 304, 305 .and arrives at a certain position, the pawls 320 on said carriage will automatically engage the first tooth 319 of the ratchet :blocks1318 :on the brackets .304, 305, and upon continued downward movement of the The shaft 309 has carriage said pawls will engage other teeth 319 of said blocks. Engagement of the pawls 320 with the first tooth 319 of the ratchet blocks 318 automatically connects the brackets 304, 305 to the separator carriage as a single unit, and this engagement is chosen to occur while a quantity of sheets of the pile still remains on the pile board 300. The plural teeth 319 on the blocks 318 provide for connecting the separator carriage with the brackets 304, 305 over a range of positions of said carriage relative to said brackets with a corresponding increase or decrease in the quantity of sheets remaining on the pile board 300. In this manner the connection between the separator carriage and the brackets 304, 305 may be made with more or less sheets remaining on the pile board 300 depending on the time required to reload the feeder, the speed at which the feeder is operated, and the thickness of the sheets being handled.

Assuming now that through continued feeding of sheets from the top of the stationary pile 20 thereof on the stool 302, the separator carriage has been lowered sufficiently, i. e., beyond the position thereof shown in full lines in Fig. 2, to bring the pawls 320 into position to engage the ratchet blocks 318 and that said pawls have engaged the first tooth 319 on said blocks, as shown in broken lines in said figure. With a quantity of sheets of pile 20 still remaining on the pile board 300 and while the feeding of said sheets still continues, the operator standing at the feed side of the feeder moves the handwheel 103 (Fig. l) inwardly and rotates the same in the proper direction and thereby raises the separator carriage and therewith the brackets 304, 305, pile board 300 and the remainder of the pile 20 of sheet thereon to the top of the feeder or other selected level, as shown in broken lines in Fig. 2, through the connection afforded by the pawls 320 and ratchet blocks 318 and through engagement of the latches 308 with the underside of said board. The brackets 304, 305 are now held in their elevated positions and against downward movement through engagement of the pawl 313 with the ratchet 312, the latter rotating idly past the pawl 313 while the brackets 304, 305 are being raised.

While sheets are being separated and fed from the top of the stationary elevated remainder of the original pile 20 now on the arms 306 of the brackets 304, 305, a second pile board 300 is placed on the stool 302 and a second pile of sheets 20 is loaded on said board, as in the case of the first pile or load, said second pile extending substantially to the underside of the elevated first pile board on the arms 306. It is to be noted that the connection afforded by the pawls 320 and ratchet blocks 318 enables downward movement of the separator carriage relative to the stationary elevated brackets 304, 305 by the described feeler controlled mechanism for this purpose as the sheets are fed from the top of the stationary elevated remainder of the first pile to maintain the sheet separating mechanisms 39 in operating position with respect to said pile.

After the second pile of sheets has been loaded in feeding position beneath the elevated remainder of the first pile as above described, and while the feeding of sheets from said first pile continues, the operator grasps the handle 316 with one hand and rotates the shaft 309 slightly in the proper direction to free the pawl 313, and then with the other hand moves the pawl 313 by the handle 315 out of engagement with the ratchet 312 and into holding engagement with the latch means 317 to release the brackets 304, 305, said brackets now being held against downward movement through engagement of the pawls 320 with the teeth 319 of the ratchet blocks 313. The handwheel 103 is then moved inwardly to disconnect the described feeler-controlled, power-actuated separatorcarriage-lowering mechanism and then rotated in the proper direction to lower the separator carriage, the brackets 304, 305, the pile board 300 and the sheets of the first pile.remaining thereon as a unit until said pile board substantially contacts the top of the new pile. The

8 handwheel 103 is then moved outwardly to again connect the feeler-controlled, power-actuated separator-carriage-lowering mechanism.

As the feeding of sheets continues, the first pile board 300 is then withdrawn rearwardly from pile supporting position and any remaining sheets of the first pile are deposited upon the top of the new pile, the feeler 70 being immediately responsive to effect lowering of the separator carriage to compensate for the withdrawal of said pile board. Suitable guides or back-stops may be employed to prevent rearward displacement of the remaining sheets with the first pile board upon rearward removal of said board. Separation and feeding of the sheets from the top of the combined new pile and remainder of the first pile and step by lowering of the separator carriage now continue through the medium of the described devices for this purpose.

Before or after the first pile board 300 has been removed from pile supporting position as above described, the handle 316 is held by the operator who also moves the pawls 320 by the handle 322 out of engagement with the ratchet blocks 318 and into holding engagement with the latch means 323 to release the brackets 304, 305. Thereupon the operator rotates the shaft 309 by said handle 316 to lower the brackets 304, 305 to the bottom of the feeder and into abutting engagement with the base brackets 27. The pawl 313 is then released from the latch means 317 and moved into engagement with the ratchet 312, and the pawls 320 are released from the latch means 323 to permit said pawls to return to their original operative positions shown in Fig. 2, in readiness for a repeat performance of the above described pile replenishing operations as necessary or required. In the downward movement of the pile lifting brackets 304, 305 to the bottom of the feeder, the latches 308 are deflected by the second pile board as they pass the latter, and then they return beneath said board.

Certain modifications may be made, if desired, in the described structure, such as for example, as shown in Fig. 4, rearwardly extending rail bars 325 may be employed in lieu of the stool or platform 302. These bars 325 are supported on standards 326 at substantially the same level as that of the upper surface of the stool 302. The bars 325 serve to support in feeding position the first pile of sheets 20 on a pile board 300 with the latter in position for engagement by the pile lifting brackets 304, 305, and they enable preparation thereon of a second pile 20' of sheets rearwardly of said first pile on a second pile board 300 while the sheets are being fed from the top of the first pile. The rails 325 have removably secured thereto in any suitable manner front and side pile guides 327 and 328, respectively, which facilitate loading of the second pile 20' of sheets on said rack. When the first pile board 300 and the remainder of the first pile 20 of sheets thereon are raised from the rail bars 325 in the manner hereinbefore described, the pile guides 327 and 328 are removed if not already removed from said rail bars and the second pile board 300 and the second pile 20 of sheets thereon are moved along the rail bars into feeding position beneath the elevated first pile and against the front pile guides 193 on the feeder. These operations are repeated as necessary or required, utilizing a preceding withdrawn pile board as the supporting pile board for a succeeding pile of sheets.

In lieu of the stool 302 or rail bars 325, the successive piles of sheets on pile boards may be truck loaded into feeding position against the pile guides 193, and the trucks utilized to support each pile while the sheets are being separated and fed therefrom, and with the pile board therefore in position for engagement by the pile lifting brackets 304, 305. Additionally, the feeder frame may be so constructed to provide two transversely spaced rearwardly extending arms for supporting each pile board and pile of sheets thereon in sheet feeding and pile lifting po sition. Further, a series of transversely extending lon- 9 gitudinally spaced slats may be employed as the sole support for each pile of sheets or they may be placed on top of the pile board in the loading of the sheets on said board. In the latter case, the pile board is made narrower than the slats so that said slats alone will be engaged by the pile lifting latches which in this case are of one-piece construction and of a length sufficient to engage and support all of the slats.

In place of the pawls 320 shown in the above figures there may be provided, at each side of the machine and as shown in Figs. and 6, a square section hardened steel rod 400 pivotally dependent from the guide blocks 35, 36 and in place of the ratchets 318 there may be provided, at each side, a roller clutch 401 the clutches being attached to the brackets 304, 305 respectively. Each clutch comprises a housing 402 fixed to the bracket and having a vertical throughway 403 for the rod. The throughway is formed with a pair of opposed tapered enlargements 404 within each of which is located a horizontal hardened steel roller 405 pressed upwardly by a spring 406. The taper is such that the enlargements form with the rod throats which taper (i. e. decrease in width) upwardly. Projections 463 on the housing between the ends of the rollers 405the rollers being longer than the width of the rod 4tl0-lirnit the inward movements of the rollers towards one another. The arrangement permits free downward movement of the rod 400 relative to the clutch but on upward movement the rollers jam against the rod in the tapered enlargements, and upward relative movement between the rod and the housing is prevented. The angle of taper of each enlargement is about 7. The rollers and the housing are hardened.

For the purpose of releasing the clutch there is provided a sleeve 410 vertically slidable in the clutch housing around the rod by means of a lever 411 fulorurned on a shaft 412 journaled in the housing. The sleeve has prongs 413 extending downwardly and engageable with the rollers to press the rollers downwardly. A latch 414 is provided for holding the lever in the roller-disengaging position. The lever 411 is fixed to the cross-shaft 412 to which is also fixed the corresponding lever at the other side of the machine so that the levers move together. The rollers may be replaced by balls. The arrangement just described has the advantage over the pawl and ratchet devices which it replaces that it avoids the difiiculty that the separator mechanism and pile support members can only be interconnected at relative positions spaced apart by the pitch of the ratchet teeth.

It will appear from the foregoing, that because of the fact that the sheet separating mechanisms and the upright conveyor cooperating therewith are capable of separating and removing sheets from an upright pile thereof during upward movement as well as during downward movement of said sheet separating mechanisms, feeding of sheets by the feeder may proceed substantially continuously, by supporting at a low level a relatively high pile until a major portion or a substantial number of the sheets have been fed from said pile, lifting the remainder of said pile to a higher level and temporarily supporting the same at said level, reloading a new pile under the raised remainder of the first pile, lowering the remainder of the first pile and depositing the same :on top of the new pile, and repeating these operations as necessary or required.

Although only a single embodiment of the present invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be expressly understood that the invention is not limited to said embodiment or to the particular type of sheet feeder disclosed and described herein. Various changes may be made in the mechanical details, some of which have been illustrated, described, and suggested herein, Without departing from the spirit and scope of the invention, as will now be apparent to'those skilled in the art. For a defini- 10 tion of the limits of the invention reference is bad primarily to the appended claims.

What'is claimed is:

'1. A sheet feeder having, in combination, means normally fixed at a low level for supporting a stationary pile of sheets, sheet separating means for separating the sheets one after another from the top of said pile and movable downwardly to substantially said level as the pile diminishes through removal of the separated sheets from said pile, means for raising said sheet separating means to a selected upper level from the lowered position it occupies at which said pile is appreciably diminished, and pile lifting means movable upwardly in unison with said sheet separating means for lifting the diminished pile from said supporting means and raising the same with said sheet separating means to said upper level.

2. Sheet feeding apparatus, comprising means normally fixed at a low level for supporting a stationary pile of sheets, sheet separating means for separating the sheets one after another from the top of said pile and movable downwardly to substantially said level as the pile diminishes through removal of the separated sheets from said pile, means for raising said sheet separating means to a selected upper level from the lowered position it occupies atwhich said pile is appreciably diminished, and pile lifting means carried by and movable upwardly with said sheet separating means for lifting the diminished pile from said supporting means and raising the same with said sheet separating means to said upper level.

3. In a sheet feeder, sheet separating means for separating sheets successively from the top of a stationary pile thereof and movable downwardly to substantially the lowermost sheet of the pile as said pile diminishes through removal of the separated sheets therefrom, pile supporting and lifting means arranged below said sheet separating means and movable upwardly to lift a remainder of said pile to a selected upper level, and means for raising said pile supporting and lifting means and the lowered sheet separating means as a single unit to bring said sheet separating means and the remainder of said pile to said upper level.

4. In a sheet feeder, sheet separating means for separating sheets successively from the top of a stationary pile thereof and movable downwardly to substantially the lowermost sheet of the pile 'as said pile diminishes through removal of the separated sheets therefrom, means for raising said sheet separating means to a selected upper level from the lowered position it occupies at which said pile is appreciably diminished, pile supporting and lifting means arranged below said sheet separating means and movable upwardly to lift the diminished pile to said upper level, and means for raising said pile supporting and lifting means.

5. ,A sheet feeder having, in combination, sheet separating mechanism arranged for vertical up and down movement and operable to separate sheets one after another from the top of a stationary pile thereof, means for lowering said sheet separating mechanism as said pile diminishes through removal of the separated sheets therefrom, a pile support arranged below sai' sheet separating mechanism for vertical up and down movement, cooperating means on said sheet separating mechanism and said pile support for connecting one with the other when said sheet separating mechanism reaches a certain level in the downward movement thereof and said pile is appreciably diminished, and means for raising said sheet separating mechanism and said pile support as a single unit after said sh'eet separating mechanism and said pile support are so connected to lift the diminished pile with said sheet separating mechanism by said pile sup port to a selected upper level, whereby a new pile of sheets may be loaded beneath the raised diminished pile while separation and feeding of sheets from said diminished pile continues. I

6. A sheet feeder as defined in claim 5 wherein the means for raising the sheet separating mechanism and pile support unit is operatively connected to said sheet separating mechanism, and said pile support is raised by said sheet separating mechanism through said cooperating connecting means.

7. A sheet feeder as defined in claim wherein said cooperating connecting means provides for connecting said pile support to said sheet separating mechanism over a range of relative positions of said mechanism and support.

8. A sheet feeder as defined in claim 5 comprising means for releasably holding said pile support and diminished pile thereon stationary in said upper level position, and wherein said cooperating connecting means provides for downward movement of said sheet separating mechanism by said lowering means relative to said stationary pile support and diminished pile.

9. A sheet feeder as defined in claim 5 wherein said cooperating connecting means comprises a depending pawl pivotally mounted on said sheet separating mechanism, and a ratchet-toothed member immovably secured to said pile support and positioned for engagement by said pawl.

10. In a sheet feeder, sheet separating mechanism arranged for vertical up and down movement and operable to separate sheets one after another from the top of a stationary pile thereof, means for lowering said sheet separating mechanism as said pile diminishes through removal of the separated sheets therefrom, means for raising said sheet separating mechanism from a lowered diminished pile position to a selected upper level, a pile support arranged below said sheet separating mechanism for vertical up and down movement, releasable means for connecting said pile support to said sheet separating mechanism for upward movement by the latter to simultaneously lift the diminished pile with said sheet separating mechanism to said upper level, whereby a new pile of sheets may be loaded beneath the raised diminished pile while separation and feeding of sheets from said diminished pile continues, means for releasably holding said pile support and diminished pile thereon stationary in said upper level position, said connecting means providing for downward movement of said sheet separating mechanism by said lowering means relative to the raised and stationary pile support and diminished pile and providing for downward movement of said pile support relative to said sheet separating mechanism after the new pile of sheets has been loaded beneath the raised diminished pile, and means for lowering said pile support.

11. A sheet feeder having, in combination, sheet separating mechanism arranged for vertical up and down movement and operable to separate sheets one after another from the top of a stationary pile thereof, means for lowering said sheet separating mechanism as said pile diminishes through removal of the separated sheets therefrom, a pile support arranged below said sheet separating mechanism for vertical up and down movement, means for raising said sheet separating mechanism and said pile support in unison after said sheet separating mechanism reaches a certain level in the downward movement thereof at which said pile is appreciably diminished, whereby the diminished pile is raised by said pile support with said sheet separating mechanism to a selected upper level to enable loading of a new pile of sheets beneath the raised diminished pile while separation and feeding of sheets from said diminished pile continues, and means for releasably holding said pile support in the raised upper level position thereof, said means for lowering the sheet separating mechanism being operable to impart downward movement to said sheet separating mechanism in the upper level position thereof relative to the raised pile support and diminished pile thereon as the sheets are separated and removed from said diminished pile.

12. A sheet feeder as defined in claim 11 wherein the means for raising the sheet separating mechanism and pile support is operable to impart downward movement to 12 said mechanism and support to bring the diminished pile adjacent to the top of the new pile of sheets.

13. A sheet feeder comprising a support at the bottom thereof for supporting a pile board and pile of sheets thereon, sheet separating mechanism arranged for vertical up and down movement and operable to separate the sheets successively from the top of said pile, means for lowering said sheet separating mechanism as said pile diminishes through removal of the separated sheets therefrom, pile lifting means arranged at the bottom of the feeder for vertical up and down movement, said pile lifting means comprising a pair of members disposed at opposite sides of said pile board, and retractile latch means carried by said members and extending beneath said pile board, depending pawl means pivotally mounted on said sheet separating mechanism, ratchet means secured to said members and arranged to be engaged by said pawl means when said sheet separating mechanism reaches a level in the downward movement thereof at which said pile is appreciably diminished, means for raising said sheet separating mechanism and said members after said pawl and ratchet means are engaged to lift said pile board and the diminished pile thereon to a selected upper level through engagement of said latch means with said pile board, whereby a second pile board and second pile of sheets thereon may be loaded on said support beneath the raised diminished pile while separation and feeding of sheets from said diminished pile continues, means for releasably holding said members and the diminished pile thereon stationary in the upper level position thereof, said pawl and ratchet means while engaged enabling downward movement of said sheet separating mechanism by said lowering means relative to the raised stationary members and diminished pile and when disengaged enabling downward movement of the raised members relative to said sheet separating mechanism, and means for lowering said members to the bottom of the feeder after the second pile has been loaded on said support and said pawl and ratchet means have been disengaged, said latch means retracting upon engagement with the second pile board and thereafter extending beneath said second pile board.

14. A sheet feeder as defined in claim 13 wherein the means for raising the sheet separating mechanism and pile lifting members is operable to lower said mechanism and members until the pile board on said members substantially contacts the top of the second pile of sheets, and said pile board when so lowered is withdrawn from pile supporting position to deposit the remaining sheets of the diminished pile on top of the second pile of sheets.

15. A sheet feeder having, in combination, sheet separating means arranged for vertical up and down movement and operable to separate sheets one after another from the top of a stationary pile thereof, means for lowering said sheet separating means as said pile diminishes through removal of the separated sheets therefrom, pile lifting means arranged below said sheet separating means for vertical up and down movement, means for raising said sheet separating means and said pile lifting means in unison after said sheet separating means reaches a level in the downward movement thereof at which said pile is appreciably diminished, whereby the diminished pile is raised with said sheet separating means by said pile lifting means to a selected upper level, and means for operating said sheet separating means at timed intervals in all vertical positions thereof and during upward and downward movement thereof.

16. In a sheet feeder, sheet separating means arranged for vertical up and down movement and operable to separate sheets successively from the top of a stationary pile thereof, sheet conveyor means arranged adjacent said pile for removing the separated sheets from said pile, means for lowering said sheet separating means as the pile diminishes through removal of the separated sheets therefrom, pile lifting means arranged below said sheet separating means for vertical up and down movement, means 13 for. raising said sheet separating means and said pile lifting means inunison after said sheet separating means reaches a leyel'inthe downward movement thereof at which said'pile is appreciably diminished, whereby the diminished pile is raised'with said'sheet separating means by said pile. lifting means to aselectedlupper level, and means for operating said sheet separatingmeans at timed intervals in timed relation with the cycle of movement of said'sheetconveyor meansand formaintaining said'timed relation as said'sheet separating means descends and during upward. movement thereof.

17. In a sheet feeder, sheet separating means arranged forvertical up and down movement and operable to separate sheets successively from the top of a stationary pile thereof; means for'lowering said sheet separating means as the pilediminishes through removal of the separated sheets therefrom, pile lifting means arranged below said sheetv separating means for vertical up anddown movement; meansfor raising said sheet separating means and said pile lifting means in unison after said sheet separating meansreaches a levelin thedownwardmovementthereof at which said pileis appreciably diminished, whereby the diminished pile is raised with said sheet separating means by said pile lifting means to-a selected upper level, and means for operating said sheet separating means at timed intervals in all vertical positions thereof and for controlling said operation such that' the timing thereof is progressively advanced'as said sheet separating means descendsand is progressively retarded as saidsheet separating means is raised:

18; In the art=of sheet feeding, the method of presenting sheets substantially continuously one after another from a supply thereof,,which comprises holding a pile of sheets stationary while the sheets are being separated and removed successively, fI'OIl'l'thBrtOP-t thereof by mechanism including sheet separating means movable downwardly as' the pile-diminishes'through removal of separated sheets therefrom and until itreaches a certain level and-said pile is appreciably'diminished, connecting said sheet separating meansat said level with the diminished pile, raising said sheet separating means and therewith the diminished pile to a selected upper level, continuing the separation and removal of sheets from the diminished pile while the latter is being raised to said upper level, and loading a second pile of sheets beneath the raised diminished first pile while separation and removal of sheets i from said diminished first pile continues.

19. In the art of sheet feeding, the method of presenting sheets substantially continuously one after another from a supply thereof, which comprises holding a pile of sheets stationary while the sheets are being separated and removed successively from the top thereof by mechanism including sheet separating means movable downwardly as the pile diminishes through removal of separated sheets therefrom and until it reaches a certain level and said pile is appreciably diminished, connecting the diminished pile with said sheet separating means at said level, raising said sheet separating means and the diminished pile in unison to a selected upper level, continuing the separation and removal of sheets from the diminished pile while the latter is being raised to said upper level, loading a second pile of sheets beneath the raised diminished first pile while separation and removal of sheets from said diminished first pile continues, and lowering said sheet separating means and therewith the diminished first pile to the top of the second pile while separation and removal of sheets from the diminished first pile continues.

20. In the art of sheet feeding, the method of presenting sheets substantially continuously one after another from a supply thereof, which comprises holding a pile of sheets stationary while the sheets are being separated and removed successively from the top thereof by mechanism including sheet separating means movable downwardly as the pile diminishes through removal of separated sheets therefrom and until it reaches a certain level and said pile is appreciably diminished, connectingthe diminished pile with said sheet separating means at saidlevel, raising said sheet separating means and the diminishedpile in unison to a selected'upper level; continuing the-separation and removalJof sheets from the diminished pile while the latter is being raised to said upper level, loading. a

second pile of sheets beneath the raised diminished" first pile while separation and removal of sheets from said diminished first pile continues, lowering said sheet separating means and therewith the diminished first pile to the top of the second pile and depositing the diminished for lowering said sheet separating mechanism as said pile diminishes through removal of the separated sheets therefrom, a pile support arranged below said sheet separating mechanism for vertical up and down movement, co-

operatingmeans on'saidsheet separating mechanism and said pile support for connecting one with the'other when said sheet separating mechanism reaches a-certain level in the downward movement'thereof and said pile is appreciably diminished, said co-operating means comprising an elongated membenon one of the parts to be connected and extending in the vertical direction and a friction clutch secured to the part to be connected arranged to make one-way clutching engagement with the elongatedmember at any position along-at least a portion of the length thereof, and means for raising said sheet separating mechanism and imparting like movement to said pile supportthrough said cooperating elongated member and a friction" clutch to lift the diminished pile with said sheet separatingmeehanism by said pile support to a selected upper level,- whereby a new pile of sheets may be loaded beneath the raised diminished pile while separation andfeeding of sheets from-said diminished pile continues.

22. A sheet feeder as claimed in claim 21 in which said clutch comprises a housing having a cam surface which co-operates with the elongated member to form a tapering throat and a roller within the throat and arranged to wedge therein on upward movement of the separating mechanism and to move out of such wedging engagement on downward movement of the separating mechanism relative to the pile support.

23. Sheet feeding apparatus for feeding sheets successively from the top of a stationary upright pile thereof, comprising sheet separating means arranged for vertical up and down movement and operable upon the top of said pile for engaging and positioning the front edge portion of each top sheet in turn for removal of said sheet from said pile, conveyor means f gripping each sheet at the front edge portion thereof and removing said sheet from said pile, means for lowering said sheet separating means as the level of the top of said pile changes through removal of the sheets successively therefrom to maintain said sheet separating means properly positioned with relation to the top of the diminishing pile, means for raising said sheet separating means from a lowered diminished pile position to a higher elevation, pile lifting means arranged to be positioned beneath the remainder of said pile and to be raised in unison with said sheet separating means to raise said remainder of said pile to a position which enables loading of a new pile of sheets in feeding position beneath the remainder of the first pile while the removal of sheets from said remaining first pile continues, and means for operating said sheet separating means and providing for continued operation thereof throughout the range of downward and upward movements of said sheet separating means.

24. Sheet feeding apparatus for feeding sheets successively from the top of a stationary upright pile thereof,

15 comprising sheet separating means arranged for vertical up and down movement and operable upon the top of said pile for engaging and positioning the front edge portion of each top sheet in turn for removal of said sheet from said pile in an upward direction, endless conveyor means arranged with an upwardly travelling reach thereof adjacent the front of said pile and extending from substantially the lowermost sheet of said pile to a level above the top of said pile for taking each sheet at the front edge thereof and removing said sheet from said pile in an upward direction, means for lowering said sheet separating means relative to said pile and said conveyor means as the level of the top of said pile changes through removal of the sheets successively therefrom to maintain said sheet separating means properly positioned with relation to the top of the diminishing pile, means for raising said sheet separating means from a lowered diminished pile position to a higher elevation, pile lifting means arranged to be positioned beneath the remainder of said pile and to be raised in unison with said sheet separating means to raise said remainder of said pile to a position which enables loading of a new pile of sheets in feeding position beneath the remainder of the first pile while the removal of sheets from said remaining first pile continues, and means for operating said sheet separating means in timed relation with the cycle of movement of said conveyor means and providing for advancing the cyclic timing of said sheet separating means relative to the cycle of movement of said conveyor means as said sheet separating means is lowered, and for retarding the cyclic timing of said sheet separating means relative to the cycle of movement of said conveyor means as said sheet separating means is raised.

25. Sheet feeding apparatus for feeding sheets successively from the top of a stationary upright pile thereof, comprising sheet separating means arranged for vertical up and down movement and including means operable toward and away from the top of said pile for lifting the front edge portion of each sheet in turn from said pile,

an endless sheet conveyor having an upwardly travelling reach arranged adjacent the front of said pile and extending from substantially the lowermost sheet of said pile to a level above the top of said pile, said conveyor carrying sheet grippers at spaced intervals therealong and operable successively to grip the lifted front edge portions of successive sheets and remove said sheets from said pile in an upward direction as said grippers travel along said reach, means for lowering said sheet separating means relative to said pile and said conveyor as the level of the top of said pile changes through removal of the sheets successively therefrom to maintain said sheet separating means properly positioned with relation to the top of the diminishing pile, means for raising said sheet separating means from a lowered diminished pile position to a higher elevation, pile lifting means arranged to be positioned beneath the remainder of said pile and to be coupled with said sheet separating means for raising movement therewith to lift said remainder of said pile to a position which enables loading of a new pile of sheets in feeding position beneath the remainder of the first pile while the removal of sheets from said remaining first pile continues, and means for operating said sheet separating means in timed relation with the cycle of movement of said conveyor and the operation of said grippers and for maintaining such timing relation throughout the range of downward and upward movements of said sheet separating means, whereby feeding of sheets from said pile in proper relation may continue during lowering of said sheet separating means as well as during raising of said sheet separating means with the remainder of said pile.

References Cited in the file of this patent UNITED STATES PATENTS 476,476 McAdams June 7, 1892 673,892 Agnew May 14, 1901 1,240,464 McCormack Sept. 18, 1917 1,248,786 Bachwitz Dec. 4, 1917

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