US2874962A - Sheet feeding system for printing presses and the like - Google Patents

Description

Feb. 24, 1959 P. w. LAYDEN 2,874,962

SHEET FEEDING SYSTEM FOR PRINTING PRESSES AND THE LIKE Filed NOV- 16, 1953 i 5 Sheets-Sheet l PAUL W. LAYDEN ATTORNEY INVENTOR v Feb. 24, 1959 P. wwLAYDEN 62 SHEET FEEDING SYSTEM FOR PRINTING PRESSES AND THE LIKE Filed Nov. 16, 1955 3 Sheets-Sheet 2 I I I I I r I 5 I I i I D INVENTOR PAUL w. LAYDEN P. W. LAYDEN Feb. 24, 1959 SHEET FEEDING SYSTEM FOR PRINTING PRESSES AND THE LIKE Filed Nov. 16, 19753 3 Sheets-Sheet 3 llll llllllll I ll ll IIIIIIIII I II INVENTOR PAUL w. LAYDEN ATTORNEY SHEET FEEDlNG SYSTEM FOR PRINTING PRESSES AND THE LIKE Paul W. Layden, Salem, Ohio Application November 16, 1953, Serial No. 392,110

6 Claims. (Cl. 271-27) The present invention relates to sheet feeding systems for printing presses and the like, and more particularly to novel and improved apparatus for feeding a plurality of paper sheets in rapid succession from a pile thereof into a printing press in accurately aligned relation to the latter.

As an overall object, the presentinvention seeks to provide a new and improved arrangement for separating a plurality of paper sheets from a compact pile or stack thereof, feeding the sheets one at a time, in rapid order and in overlapped relation toward a printing press, and accurately aligning the sheets with the press immediately prior to feeding the sheets thereinto.

More specifically, the present invention seeks an improved arrangement for initially separating'a plurality of paper sheets from a pile thereof so that the sheets may be accurately and positively gripped by a feeding device and fed inrapid succession toward a printing press, for example. In this respect the invention contemplates the use of a sheet feeding device of the general type shown and described in my co-pending application Ser. No. 220,375 filed April 11, 1951, which has matured into U. S. Patent No. 2,714,006, which is positioned over the rear edge of a pile of sheets and arranged to engage individual sheets and feed the same in extremely rapid succession, in overlapped or streamfeed relation, toward a printing device.

As will be readily understood, a plurality of sheets in stacked relation have a certain tendency to stick together, hampering the proper operation of the feeding device, and in many instances tending'to cause feeding of two or more sheets at a time. This is of course particularly true where the sheets have undergone a previous printing operation. Accordingly, the' present invention seeks to provide an improved apparatus, positioned adjacent the sheet feeding device, for separating the sheets prior to engagement of the same by the feeding device, and for facilitating such engagement whereby the feeding operation may be carried out as rapidly as the capacity of the feeding devicewill permit.

Another object of the invention is the provision of an improved means for incorporation into a sheet feeding system of the general type contemplated, whereby individual sheets of paper fed in overlapped or streamfeed relation toward a printing press or similar device may be accurately aligned or registered with suchpress or device prior to being fed into the same. i a

In many types of printing operations, and particularly in multi-color printing, wherein sheets arefed into a press a number of times, a different color being applied in each instance, it is necessary that the sheets be in substantially exact registry with the press, lest there be noticeable overlaps and voids in the color scheme, re-

2,874,962- Patented Feb. 24,1959

are fed at a substantially higher rate of speed than in conventional systems. i

In connection with the above, it is another object of the present invention to provide a sheet registering arrangement for incorporation into my general feeding system which is operative to quickly and accurately move misaligned sheets into exact or substantially exact registry with the printing apparatus and maintainthe sheets in such registry until the sheets are gripped and drawn away.

by the press.

Yet another object of the invention resides in the provision of an improved and novel sheet registering device of the type described above which is adapted to exert a high initial guiding force to a misaligned sheet, causing the same'to be moved toward a fixedqguiding member, and to thereafter maintain a substantially reduced guiding force upon the sheet so that the registry thereof is properly maintained until the sheet is gripped and drawn into the press. The desired arrangement is such that the sheets are rapidly moved into proper registry, so that the feeding system may be operated at high speed, while upon the sheets being moved into proper registry a reduced guiding force is applied thereto to prevent buckling or bounce-back of the sheet.

The above and other objects and advantages of the invention will become apparent upon full consideration of the following detailed specification and accompanying drawing wherein is shown apreferred embodiment of my invention. t

In the drawing:

Figure l is a simplified side elevation of the sheet feeding system of my invention; a

Figure 2 is an end elevation of the apparatus of Figure 1;

Figure 3 is an enlarged fragmentary view of .the apparatus of Figure 1, illustrating my improved sheet separating apparatus;

Figure 4 is a fragmentary top plan view of the apparatus of Figure 1 illustrating certain details of my improved sheet registering apparatus;

Figure 5 is a simplified fragmentary view of the apparatus of Figure 1, illustrating parts of my sheet registering apparatus; and

sulting in an inferior and in many instances completely and described in my co-pending application Ser. No.

220,375 filed April 11, 1951, now U. S. Patent No. 2,714,006, wherein a plurality of sheet-engaging suckers 17 rotate generally about an axis 18, subject, however, to a modifying motion which is eifected by'a cam 19 in such manner that a plurality of suckers 17 are simultaneously in sheet-engaging and sheet-moving relation while other suckers 17' are accelerated and rapidly returned into feeding relation with the pile-10. In accordance with the teachings of my prior invention the suckers 17 are preferably of the telescoping type whereby upon the same moving into operative relation with the pile sheet-engaging cups 18 are moved downwardly into en,- gagement with the uppermost sheet of the pile 10 and then drawn upwardly with the sheet. After a sheet has been moved forwardly a.'short distance the next succeed:

ing sucker engages a sheet and begins to move the same forwardly underneath the previous sheet. A continuous stream of such sheets is thus fed in overlapped or streamfeed relation into the conveyor 13 where the sheets are brought into registry with the printing press 15 and then: engaged and drawn into the press 15 by means of a gripping roll 16 or other suitable device.

Depending primarily-upon the width of the sheetsto be fed, the feeding system of my invention maybe arranged to incorporate one or a plurality of feeding devices 12. Thus, inthe"illustratedembodiment of the invention I have-provided a pair of spaced feeding devices positioned adjacent each side of the pile 10, over the rear edge thereof, so that eachsheet is engaged at its rear corners for feeding. Of course, both feeding devices 12 are substantially identical and are arranged to operate. in synchronism. Preferably, a common shaft defining a com mon axis 18 drivesboth devices.

In order to obtain extremely high speed feeding, as has been made possible by my feeding device 12, it has been found necessary to insure-proper separation of the sheets of? the. pile 10 to thereby insure that the same are fed in one-at-a-time relation. And it has also been found desirable to buckle or fluff the uppermost sheet of the pile 10 so that the suckers 17 more quickly and readily engage: the sheet for feeding in the manner desired.

Thus, in accordance with suggestions of the prior art I have positioned adjacent each rear corner of the pile 10 a nozzle 20 of right angular shape, each of the nozzles being provided with apair of elongated vertically disposed outlet openings 21 directed toward the edge of the pile- 10 adjacent the uppermost few sheets thereof. Each of: the nozzles 20 has a. supply conduit 22 communicating with a source of compressed air, not shown, whereby streams of air may be directed toward; the top sheets of the pile; toeifect a separation of the rear edge. portions of the sheets.

Positioned directly above the pile 10, adjacent each rear corner thereof, and disposed generally at right angles with respect to. the. axis; of feeding movement, are suction wheels 23 which are keyed or otherwise connected with shafts 24 and adapted to be rotated therewith at a relatively high rate of speed by any suitable means, not shown. As illustrated in Figure 3, each of the suction wheels 23 is provided with a plurality of spaced radially directed bores 25,'whichbores are intercepted by a like plurality of axially directed bores 26 located concentrically about the shaft 24. As shown in Figure 1 the outer openings of the bores are axially elongated so that a substantial effective suction area is afforded while the circumferential dimension of the bores is maintained at a minimum. Positioned adjacent each wheel 23 in a valving member 27 having, a recess 28 therein which is arranged tocommunicate with one of the axial bores 26. In the preferred construction the valve member 27 is fixed, and the recess 28 is located below the. shaft 24 so that only the lowermost bore 26 will be in'c ommunication with the recess atany one time. I Also communicating with the recess 28, and extending outwardly of the valving member 27, is a short nipple 29 which is adapted to be connected to a suitable vacuum pump or device, not shown, whereby suction may be applied to the lowermost of the radial bores 25 when desired.

Referring again to Figure 2, there is shown a pair of air blast feet 30 positioned over the pile 10, adjacent the real-edge thereof and between the spaced feeding devices 12. In" accordance with known feeder design the feet 30 are provided with forwardly directed nozzle portions 31, and are arranged to communicate with a suitable source of compressed air, not shown, so that when a sheet of p'aper is lifted from the pile 10 by the feeding devices 12, as'shown in Figure 2, one or more streams or blasts of air may bedirected along the lower surface of the lifted sheet so that the same-is separated and freed from the I underlying sheet for easy forwardfeeding. Alsoih accordancezwith'known feeder'design, the blast feets30 are;

mounted for timed vertical movement toward and away from the top of the pile-10, the arrangement beingsuch that whenever a sheet is engaged by the feeding devices 12 the feet 30 rise to permit the engaged sheet to be withdrawn, whereupon the feet are lowered, simultaneously clamping the next sheet to the top of the pile and sending a blast of air beneath the raised sheet to facilitate the feeding thereof toward the press.

If desired, the feet 30- may be further employed as detecting devices for the purpose of energizing a pile raising mechanism, not shown, whereby to maintain the top level of the pile- 10 in predetermined'relation with the feeding devices12. This is also in accordance with known principles of sheet feeder construction.

The operation of my sheet separatingand feeding arrangement may be ascertained by reference to Figures 1-3 of the drawing. As shown in Figure 3, the uppermost few sheets of the pile 10 are initially separated along the rear edges by means of strong air blastsissuing'from the vertically disposed openings 21- of the separating nozzles 20. The uppermost one of the sheets thus separated is forced upwardly intounderlying relation with the suction wheels 23 which, in accordance with the teachings of the invention, are rapidly rotating in the. directions indicated so that the lower surfaces of the wheels move inwardly over the pile. By means of the recess 28 and nipple 29, in the valving member 27 of each suction wheel, suction is applied to the lowermost radial bore 25 whereby the uppermost sheet of the pile is frictionally engaged at its rear corners by the wheels 23 and urged in the direction of travel of the wheels.

. At this time the blast feet 30 are in lowered or clamp ing relation to the pile 10 so that the uppermost sheet is firmly held in. place. The result is that the corners of the upper sheet are buckled upwardly in the manner shown in Figure 2. And in accordance with the teach ings of the.- invention the buckle thus produced is positioned substantially directly beneath the continuously rotating feeding devices 12 so that the sheet is'readily engaged by apair of extended suckers 17 of the devices 12. Substantially at the instant the sheet is engagedv by a pair of suckers 17 the blast feet 30 move upwardly to release the upper sheet and permit forward movement thereof in the manner desired. And an instant later, after the upper sheet has been moved forwardly a sufiicient distance to clear the blast feet 30, the latter are. lowered into clamping relation with the pile 10 and blasts of air are directed forwardly from the feet 30 to lift the forward edge of the moving'slieet to assist its proper feeding toward the press.

Thev above'described cycle of'operations is repeated in rapid succession in normal operation, causing a continouus streamof sheets to. be fed in overlapping relation toward the printing pressv 15 in the manner desired.

An important feature ofrthe invention is the suction wheel arrangement wherein the. suction openings in the wheels are axially elongatedwhile being of a minimum size in a circumferential direction. The arrangement is such that a beating action is imparted to the paperto insure the separation of the uppermost sheet from other sheets which may tend to adhere thereto. The beating action is, however, effected without mutilation of the sheet, as sometimes occurred with apparatus of the prior art. i v

To convey the separated and initially moved sheets from the pile: 10 to the press 15 it is. conventional to provide a conveyor device 13, comprising a pair of spaced rolls-32 and 33 and a plurality of endless belts 34. pressure roll 35 cooperates with the forward conveyor ro1l 32 to frictionall'yengagcsheets fed from the pile 10 and causethe same, t'o 'be properly conveyed to the moving belts 34'. -An-d-,also in. accordance with usual constructiona suitable hold-down device 36 is provided which is positionedover the bclts'.34 and arranged to In. accordance with usual construction a suitable bear lightly upon sheets carried by the belts 34 so a relatively positive feeding movement is afforded. Preferably the hold-down device 36 comprises a plurality of universally movable balls 37 so that sheets may be readily moved in a longitudinal or feeding direction, or in a transverse direction as may be desired. i

It is of course necessary in most printing operations to accurately align and register the conveyed sheets with the printing press prior to the sheets being fed thereinto, and this of course contemplates transverse as Well as longitudinal registry with the printing apparatus. Longitudinal registrymay be readily effected by providing a plurality of retractible head stops 38 which are arranged to engage the forward edges of individual sheets as the same are conveyed into position for feeding into the press 15. As illustrated in Figure l, the press may be provided with a suitable sheet gripping roll 16 having clamps 39 thereon which are arranged to engage a longitudinally registered sheet at its forward edge portion, and at a predetermined time, after retraction of the head stops 38, to draw such sheet into the press 15.

In order to effect proper transverse registry of the conveyed sheets I conventionally provide a laterally adjustable side guide member 40 (see Figure 4) which is positioned along one side of the conveyor 13 and which is so positioned with respect to the press 15 that any sheet which is in contact along its side edge'with the guide 40 is in proper transverse registry with the press.

In orderto insure that each sheet conveyed to the press 15 is in proper guiding contact with the guide member 40 I have provided a novel arrangement which includes a pair of suction wheels 41 and 42, positioned one on each side of the passline of the conveyor 13 so as to contact respectively the upper and lower surfaces of each sheet conveyed to the press. In accordance with the teachings of the invention a motor 43 or other means is provided to rapidly rotate the wheels 41 and 42 in such a direction as will tend, when suction is applied to the wheels, to move the sheet engaged thereby laterally toward the side guide member 40.

As previously mentioned, my overall feeding system is intended to operate at exceptionally high speeds, in the order of 20,000 sheets per hour, for example, and accord ingly the transverse or side register device 14 must also be capable of high speed operation. This is particularly true since, in the preferred operation of the apparatus transverse movement of the sheets to effect side registry is effected after the leading edge of the sheet has engaged the head stops 38 but before the gripping roll 16 draws the sheet into the press 15. It will be readily apparent the interval of time thus afforded for effecting side registry of each individual sheet is of a small magnitude.

Thus, in accordance with the teachings of the invention I have connected each of the suction wheels 41 and 42 of the side register device through valve members 44 and 45, respectively, and suitable conduit means to a suitable vacuum pump, not shown, so that upon periodic application of suction to the continuously rotating wheels 41 and 42 a sheet of paper positioned therebetween will be caused to move transversely toward and into contact with the guide member 40. As will be readily understood, in view of the unusually short interval of time provided. for effecting proper side registry of the sheets the suction applied to the rotating wheels41 and 42 must be of a comparatively high magnitude, so that within the interval provided a sheet may be moved into registry from a possible extreme out-of-register position. Of course, the majority of sheets fed by the conveyor device 13 will not be so far out of register, and it has therefore been found necessary to reduce the moving force of the wheels 41 and 42 toward the end of the registering operation so-that the sheets do not become buckled and skewed with respect to the side guide 40 and press 15. Accordingly, as one of the important features of my invention, I have provided a variable relief valve 46 in the to the wheels 41 and 42. As shown in Figure 6, the

valve 46 comprises a body 47 having inlet and outlet parts therein for the suction line, indicated schematically at 48, and an additional port 49 leading to the atmosphere and normally closed off by means of a ball check 50 and spring 51. A nut 52 is retained in the upper portion of the valve body 47, which nut slidably retains a control plunger 53 which bears against the spring 51.

As the valve 46 is employed in the present apparatus, it is intended to limit the application of suction to the wheels 41 and 42 by admitting air through port 49 whenever the pressure differential between the conduit 48 and the atmosphere become great enough to lift the ball 50 off of its seat. The pressure differential at which the ball 50 is lifted may be regulated in the first instance by the setting of nut 50, which provides a. normal limit position for the plunger 53, and in the second instance by the setting of the plunger 53 with respect to the nut 52. Thus, in Figure 6 the plunger 53 is illustrated in its uppermost position wherein the ball 50 may be most easily lifted off its seat to admit air through port 49. If the plunger is depressed, however, the spring 51 applies a greater restraining force to the ball 50 and a greater pressure differential must exist between the conduit 48 and the atmosphere before the ball 50 will lift off its seat. Thus, when the plunger is depressed a maximum suction is applied to the wheels 41 and 42, while when the plunger is in its uppermost position the suction applied at the wheels 41 and 42 will be at a predeterminedminimum.

To operate the valve 46 synchronously with the feeding of sheets to the press 15.I have provided a cam 54 which is operatively associated with the press 15, as schematically indicated at 65, for example. And the arrangement is such that the cam 54 will make one complete revolution for each sheet of paper gripped and drawn into the press 15 by the sheet gripping roll 16.

As above mentioned, it is desirable, after a sheet has engagedthe head stops 38, to apply a strong suction force to the wheels 41 and 42 to effect a rapid transverse movement of such sheet. Accordingly, the cam 54 is provided with a raised surface portion 54a which is arranged, upon appropriate rotation of the cam 54, to fully depress the plunger 53 to retain the check ball 50 most firmly in its seat. In accordance with the teachings of the invention, the contoured surface of the cam 54 gradually recedes from the raised portion 54a so that, as the cam rotates, a progressively diminishing suction is applied to the wheels 41. After, for example, about degrees of rotation of the cam 54 the .suction is at a predetermined minimum of, for example, ten percent of the maximum, sufiicient to retain the sheets in proper engagement with the side guide 40 without causing any buckling or skewing of the sheets.

Also in accordance with the teachings of the invention, it is desirable to completely deenergize the wheels 41 and 42 during feeding of sheets into the press 15 and during longitudinal travel of the sheets into engagement with the head stops 38 and for this purpose I have provided a second valve 55. The valve 55, illustrated In Figure 6, is provided with a spring biased operating plunger 56 which is actuated by a cam 57 arranged to rotate in synchronism with the suction control cam 54. The desired arrangement is such that upon engagement of a sheet with the head stops 38 the plunger 56 will be raised to open the suction line 48, whereupon sliction is applied to the wheels 41 and 42 in a controlled manner, as determined by the contour of cam 54. At

or slightly before the instant a sheet is gripped and drawn into the press 15 the cam 57 causes the plunger 56 to be depressed to disconnect the wheels 41 and 42 from the vacuum source therefor, and in accordance with the preferred operation the wheels remain deenergized until the nextsubsequent sheet engages the head strips 38.

Generally, it is desirable in sheet feeding systems of the type herein contemplated to provide means for detecting the passage through the feeding system of a double thickness of paper and to stop the printing press and feeding system to prevent the passage through the press of such double thickness. In the present apparatus I may advantageously employ the suction wheels 41 and 4-2 for this purpose. As illustrated in Figure 1 the transversely disposed wheels 41 and 42 are provided with rounded outer surfaces whereby sheets traveling parallel to the axis of rotation of the wheels may readily pass therehetween. Preferably the lower suction wheel 42 is mounted for rotation about a fixed axis, as indicated in the simplified View, Figure 5, while the upper wheel 41 is mounted for rotation about a vertically movable axis afforded by a pivotally mounted journal member 58. In the illustrated embodiment of the invention, the journal member 58. is spring biased in a downward direction, and is provided with an elongated operator 58' which engages at' its outer end a sensitive type limit switch 59 which is of a type adapted to be actuated upon a small movement of the operator 58'. The desired arrangement is such that upon the passage between the wheels 41 and 42 ofa single sheet of paper the switch will remain in a closed condition, but that upon the passage between the wheels of two or more sheets the switch 59 will open, stopping the press and feeding system so that the situation may be corrected without damage to the apparatus.

Thus, it should be apparent that I have accomplished the objects initially set forth. There is provided by my invention a sheet feeding system of a substantially improved nature, capable of feeding sheets in rapid one at-a-time relation, at. substantiallyhigher rates than has been heretofore thought practical, in order that full advantage may be taken of the capacities of the sheet feeding device constituting the subject matter of my previously identified co-pending application.

One aspect of my improved sheet feeding system relates to the initial separation of the sheets from a compact pile thereof and the conditioning of the uppermost sheet of such pile for ready engagement by the feeding device of my prior invention. Thus, I have provided a pair of continuously rotating transversely disposed suction wheels, positioned at each rear corner of the pile, and adapted to engage the uppermost sheet of the pile to buckle the same upwardly at a point below the feeding device or devices whereby the same may readily and positively engage such sheet for feeding toward a printing press or the like. My separating apparatus is novel in that a beating action is obtained to insure proper separation, while the sheets are not marred or harmed in any way. I obtain this result by providing axially elongated suction apertures which afford substantial gripping area while having a minimum circumferential dimension. The arrangement is such that there tends to be an instantaneous release of the paper by one suction opening before the next succeeding opening comes into gripping contact with the, paper. Thus, a vibrating or beating action is obtained which insures that the uppermost sheet will be properly separated from lower sheets tending to adhere thereto.

Another important aspect of myinvention resides in my novel side registering apparatus which is capable of moving individual sheets into accurate registry with the printing press or other apparatus at the high rates of speed possible in my overall feeding system. I have provided a pair of rapidly and continuously rotating suction wheels to which is applied, for the positioning of each individual sheet,.an.initially high'but gradually diminishing suction force, which force is entirely removed upon the 'sheet being gripped for feeding intov the press. The arrangement is such that the sheets are given a relatively strong accelerating force initially so that proper positioningof the sheets in registry is assured, while such force is reduced to a small fraction of the initial force prior to feeding the sheet into the press whereby buckling or skewingof the sheet, as might otherwise be caused, is wholly avoided. By means of a novel valving arrangement, which is operatively associated with the operation of the printing press, I may energize and deenergize the side register wheels 41 and 42 at the exact moments desired, and may accurately control the force applied by such wheels through the period of energization so that optimum operating results are obtained at all times.

It should be understood, however, that the apparatus herein specifically shown and described is intended to be representative only, and reference should therefore be had to the appended claims in determining the true scope of the invention.

Iclaim:

1. In a sheet feeding system of the type having means for feeding sheets one at a time from a pile thereof in rapid streamfeed relation toward a printing press, the combination of a conveying device arranged to receive sheets in streamfeed relation from said means for feeding, a guide member positioned adjacent said conveying device and located in predetermined relation with respect to said press, means to apply suction to each of said sheets independently of said conveying device for urging the same toward said guide member, said last mentioned means including means to apply aninitial relatively high suction, said last mentioned means further including means to progressively reduce said suctionas said sheet moves toward and abuts against said guide member prior to feeding said sheet so acted upon into the press, said means to apply suction to each of said sheets comprising a rotating suction Wheel adapted to engage the surface of said sheet, means to supply suction to said suction Wheel, said means to progressively reduce said suction comprising valve means interposed in said means to supply, said valve means comprising a suction passageway, an exhaust port communicating with said suction passageway, closure means for said exhaust port, yieldable biasing meansassociated with said closure means for normally maintaining said exhaust port closed, and means for changing the force exerted by said yieldable biasing means on said closure means as said sheet moves toward said guide member.

2. Apparatus according to claim 1 further comprising means to block said means to supply suction to said suction wheel prior to feeding of said sheet into said press, and means to release said means to block said supply of suction upon a subsequent sheet moving into operative relation with respect to said suction wheel. I

3. In a sheet feeding and registering system comprising conveying means operative to feed sheets one at a time from a pile thereof to other apparatus in rapid streamfeed relation, a guide member positioned adjacent said conveying means, means to apply suction to each of said sheets independently of said conveying means for urging the same toward said guide member, said last mentioned means including means to apply an initial relatively high suction, said last mentioned means further including means to progressively reduce said suction as said sheet moves toward and abuts against said guide member, means to block said'means to apply suction after a sheet has moved into registry'with said guide member, means to release said means to block upon a subsequent sheet moving into sheet registering'position, said means to block comprising valve means, means operating said valve means, and said means operating being operated synchronouslywith the apparatus to which said sheets are fed.

4. In a sheet feeding and registering system comprising conveying means operative to feed sheets one at a time from a pile thereof to other apparatus in rapid streamfeed relation, a guide member positioned adjacent saidconveying means, means to apply suction to each of said sheets independently of said conveying means for urging the same toward said guide member, said last mentioned means including means to apply an initial relatively high suction, said last mentioned means further including means to progressively reduce said suction as said sheet moves toward and abuts against said guide member, means to block said means to apply suction after a sheet has moved into registry with said guide member, means to release said means to block upon a subsequent sheet moving into sheet registering position, and said means to apply a relatively high suction, said means to progressively reduce said suction, said means to block and said means to release said means to block being operated synchronously with the apparatus to which the sheets are fed.

5. In a sheet feeding and registering system comprising conveying means operative to feed sheets one at a time from a pile thereof to other apparatus in rapid streamfeed relation, a guide member positioned adjacent said conveying means, means to apply suction to each of said sheets independently of said conveying means for urging the same toward said guide member, said last mentioned means comprising means to apply an initial value of suction, said last mentioned means further comprising means to progressively change said suction as said sheet moves toward and abuts against said guide member, said last mentioned means comprising a valve having a suction passageway and an exhaust port, closure means for said exhaust port, yieldable biasing means associated with said closure means for normally maintaining said exhaust port closed, a protruding operator connected with said yieldable biasing means, and cam means operative to move said operator in synchronism with the apparatus to which said sheets are fed.

7 conveying means operative to feed sheets one at a time from a pile thereof into other apparatus in rapid streamfeed relation, a guide member positioned adjacent said conveying means, means to supply suction to each of said sheets independently of said conveying means for urging the same toward saidguide member, said last mentioned means comprising means to apply an initial value of suction, said last mentioned means further comprising means to progressively change said suction as said sheet moves toward and abuts against said guide member, said means to apply comprising a rotating wheel mounted for movement toward and away from said conveying means, and switch means associated with said wheel operative in the simultaneous passage adjacent said wheel of more than one sheet thickness to stop said sheet feeding and registering system.

References Cited in the file of this patent Netherlands Oct. 16, 1950

Images