US2714006A

US2714006A - Sheet feeder

Info

Publication number: US2714006A
Application number: US220375A
Authority: US
Inventors: Paul W Layden
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-04-11
Filing date: 1951-04-11
Publication date: 1955-07-26
Anticipated expiration: 1972-07-26

Description

July 26, 1955 P. w. LAYDEN 2,714,006

SHEET FEEDER Filed April 11, 1951 4 Sheets-Sheet l Enventor PAUL W. LAYDEN %Mmf (I omeg July 26, 1955 E P. w. LAYDEN SHEET FEEDER Filed April' 11, 1951 4 Sheets-Sheet 2 li In W D 'IIHI In! .I! I 5 57 I 24 o t In WWI 24c I 4o 62 o 57 3mm PAUL LAYDE July 26, 1955 P. W."LAYDEN 2,714,006

SHEET FEEDER Filed April 11, 1951 4 Sheets-Sheet 3 3twentor PAUL w. LAYDEN attorney July 26, 1955 Filed April 11, 1951 P. w. LAYDEN 2,714,006

SHEET FEEDER 4 Sheets-Sheet 4 Snnentor PAUL W. LAYDEN United States Patent EEDER Paul W. Layden, Salem, .Ohio

Application April, 11, 1951,, Serial No. 220,375

12 Claims. (Cl. 271-48) This invention relates to. automatic apparatus for feeding sheets individually off a pile in overlapped relation in the manner commonly termed stream feeding. The application of automatic devices for this purpose in the printing industry, for example, is Well understood but the necessity remains for continued improvement in the design and operation of such feeding devices in order that the full production capabilities of lately designed printing machines may be realized. Thus, rotary offset lithograph presses, forexample, of modern design are capable of extremely high rates of production and their productive capacity is in fact now limited primarily by the inability of known feed devices to dependably feed individual sheets in succession to them. It is accordingly the primary object of this invention to, provide an improved sheet feeding apparatus which is entirely practical in design but which is capable of feeding successive sheets from the top of a pile in an unfailing manner and at an extremely high rate of speed.

An important object of the present invention is the provision of improved apparatus for the purposes stated which is operative to dependably break away the individual sheets from the topv of a pile and to move the same in overlapped progression laterally oif the top of the pile by means of moving mechanical elements having primarily rotary or uni-directional movement as distinguished from reciprocating movement which has heretofore been the greatest limiting factor in holding down the speed potentialities of sheet feeding devices. This general object is accomplished by the present invention by mounting the sheet engaging and moving elements of the assembly on a movable carrier which has predominantly a uniform rotary motion. Such sheet en: gaging and moving devices are preferably movable suction pads and while it has been heretofore proposed to mount similar pads on rotary carriers the attempts have been wholly unsuccessful and it has accordingly been considered necessary to carry these suction pads on re ciprocating structures, The present invention, however, provides a novel method of mounting the suction devices on the rotary carrier and of controlling the instantaneous relative movement of the devices with respect to the carrier whereby an optimum cycle of movement of successive suction devices with respect to successive sheets on the pile is effective to thereby insure the breaking away of these successive sheets from he pile and their lateral displacement with respect thereto at high speeds and without the requirement of reciprocatory movement of the suction devices.

A more specific object of the invention is the provision in sheet feeding apparatus employing telescopic suckers to engage and move successive sheets on a pile of an improved arrangement for movably carrying the suckers whereby the latter have a more optimum pattern of movement but without objectionable reciprocation. as required heretofore, whereby a greater part of the time cycle of each sucker is available foruseful Work to thus improve dependability of operation, and whereby a slight bachice ward movement may be imparted to each successive sheets to assist in breaking the same loose from the pile without requir ng ec p f e en r f mass of the sucker assembly during such portion of its pattern of mo emen Yet another object of the invention is the provision in high speed sheet feeding apparatus having the characteristics outlined above of an improved arrangement for timing and controlling the application of suction to the successive telescoping suckers at the start of a run to insure initial and continuing synchronization of the first and succeeding suckers with respect to the first and succeeding sheets to thereby avoid any possibility of fouling the associated press, for example, and avoiding the wastage of stock.

The above and other objects and advantages of the invention will become apparent upon consideration of the following detailed specification and the accompanying drawing wherein there is fully disclosed a preferred embodiment of the invention.

In the drawing:

Figure 1 is a front elevation of a portion of a sheet feeder constructed in accordance with the principles of my invention;

Figure 2 is a, vertical section through the feeder of Figure 1, the view being taken along the line IIII of Figure 1; 7

Figures 3 and 4 are a side elevation and a sectional view, respectively, of one of the pivotally mounted telescoping sucker units utilized in the assembly of Figures 1 and 2;

Figure 5 is a schematic representation of the pattern of movement of the various sucker units utilized in the assembly of Figures 1 and 2;

Figure 6 is an inside elevation of one of the cam and valving plates of the machine of Figure 1;

Figure 7 is a plan view of a starting control gate which overlies the plate of Figure 6;

Figure 8 is an end view of a mounting collar which overlies the gate of Figure 7 and which pivotally receives the pintles of the telescoping sucker units;

Figure 9 is a sectional view of a control pin carried by the gate of Figure 7;

Figures l0, l1 and 12 show start, intermediate, and finalposition of the starting gate at the start of a feed run; and

Figure 13 is a fragmentary view of a modification utilizing a modified form of movement controlling cam to secure an initial backward movement of the telescoping sucker immediately upon the latter being affixed to a sheet.

Being a stream feed device, the telescopic suckers uti-. lized in my invention must engage the rear edge portions of the successive sheets of the pile and after breaking the sheets loose from the pile impart a lateral move: ment to the sheets so that the latter may be engaged in succession by the high speed feed rollers of the printing Pressa fo e amp e- Th man e n wh c th s accump ished an the ppara us devised to accomplish it is th of h n ntio an Will e esc d in detail below but, first, l desire to point out that, in

common with the prior art, I utilize a controlled lift for thepile or stack of sheets to be f ed so that the top of the pile always bears a reasonably fixed position relative to the feeding mechanism of my invention. A schematic showing of such elevating mechanism is included in Figure 2 wherein reference numeral 10 designates a base for supporting a pile of sheets 11 and the base 10 is, in turn, supported by a ratchet bar 12 arranged to be elevated in step-by-tstep movement by a lever 13, the ratchet bar 1-2. e g ld. in upp P O by a og 14- A sol noid 1 a r nged to be P r od ca ly n:

ergized by a circuit 16 may be employed to actuate the lever 13.

In the illustrated embodiment of the invention there is a rigid frame comprised of a pair of uprights 17 and 18 (Figure 1) which have rigidly attached thereto a pair or"

clamps

19 and 20 which may be secured to beams, not shown, extending outwardly from a printing press, for example, whereby the feeder of my invention may be mounted in rigid fixed relation to such press including the feed rollers thereof. Rigidly secured to and spanning the upper ends of the

uprights

17 and 18 is a horizontally disposed beam 21 having a pair of spaced brackets 22 and 23 depending downwardly therefrom. Rigidly secured to the bracket 23 in depending relation thereto is a combined cam and valving plate 24 which has a cam-shaped outer periphery as shown in Figures 2 and 6 and which has a centrally disposed aperture for the passage of a shaft 25 which is journaled in

bearings

26 and 27 rigidly affixed on the

uprights

17 and 18, respectively. As shown in Figure 6 cam 24 has, on its inner face, an arcuate groove 28 which is concentric about the central aperture and communicating with the space in the groove 28 is an aperture 29 to which is connected a suction hose 30. Also concentric about the central aperture in cam 24 but radially outward of the groove 28 and circumferentially offset with respect thereto is an arcuate slot 30, the function of which will be described in detail below. Rigidly secured thereto and depending from the bracket 22 is a second cam plate 31 which has an outer periphery identical with the outer periphery of the cam and valving plate of the cam 24.

Keyed to the shaft 25 is a pair of

collars

32 and 33 having a plurality of circumferentially spaced axial bores 34 and it will be understood that the bores in one collar are axially aligned with the bores in the other collar. For a purpose to be later described, a plate-like starting gate 35 is rotatably mounted on the shaft 25 intermediate the cam 24 and the collar 33 in flat relation to the latter two elements and by referring to Figure 7 it will be noted that the gate 35 has a plurality of circumferentially disposed apertures having radial spacing coincident with the radius of the groove 28 in cam 24 and with the radial spacing of the apertures 35 in the collar 33. Gate 35 has an integral radially extending tab 37 mounting a barrel 38 in which is slidably received a spring-press plunger 39 to the outer end of which is attached a headed knob 40. The spring 41 in barrel 38 biases plunger 39 to the projected position shown in Figure 9 but the knob may be engaged to withdraw the plunger 39 into retracted position within the face of the gate plate,-

Rotatably received in the aligned apertures in the

collars

32 and 33 are the pins 42 of the telescoping sucker assemblies, one of which is shown in detail in Figures 3 and 4. Each sucker assembly, herein designated generally by the reference numeral 43, comprises a body member 44 having a longitudinally extending bore 45 adapted to slidably receive a piston 46 on the inner end of a plunger rod 47 which is guided in a sleeve 48 pressfitted into the outer end of bore 45 and carrying at its outer end a suction cup 49 preferably of rubber. Piston 46, rod 47, and cup 49 are centrally apertured whereby air may be withdrawn from the cup 49 outwardly through the inward end of the bore 45. Body member 44 is apertured transversely to slidably receive the pintle 42 which is locked therein by the drive pin 50 and, as shown, one end of the pin 42 is bored longitudinally inward as at 51 for communication with

passages

52 and 53 formed in the body member 44. Passage 52 leads to the inward end of bore 45 and is adjustable by means of a set screw 54 while passage 53 leads to the space in bore 45 between piston 46 and guide sleeve 48. In assembly, the bored end of the pin 42 is inserted in the collar 33 so that suction may be applied to the

passages

52 and 53 through the

passages

51, 34, 36, 28 and 29. A coil spring 55 is interposed between sleeve 48 and piston 46 to normally retain the cup 49 in retracted position. Considering now the operation of the assembly shown in Figure 4 wherein the parts are shown in normal unenergized positions it will be observed that upon suction being applied to

passages

51, 52 and 53 the rod 47 and cup 49 will move outwardly due to the decrease in pressure on the rod end of piston 46. At this time the pressure on the head end of piston 46 does not decrease appreciably because this space is open to the atmosphere through the passage provided in piston 46, rod 47 and cup 49 and the effective cross-sectional area of the passage 52 may be held down by adjustment of screw 54. If now the outer face of the extended cup 49 is closed off by its engaging a fiat sheet of paper, for example, the pressure on the head side of piston 46 will drop rapidly due to the continued evacuation through passage 52 and the rod 47 and cup 49 will be retracted, carrying sheet of paper along with the cup. This operation is utilized by my invention in separating an edge portion of the individual sheets from the pile of sheets. The coordination of this action with other assists and movements will be described more fully below.

Each of the sucker assemblies 43 has a rigidly attached arm 56 mounting at its outer end a roller 57 which rides on the peripheral cam surface of one or the other of the two

cam plates

24 and 31. Further, a coil spring 58 is provided for each of the sucker assemblies 43 to pivotally bias the same so that the rollers 57 are maintained in contact with the peripheral cam surfaces of the

plates

24 and 31. The need for the two

plates

24 and 31 arises out of the requirement for a special pattern of orbital movement of the sucker assemblies 43 which makes it physically impossible to control the movements of all the sucker assemblies from a single cam. I have found that five suckers are sufiicient to provide a practical machine and in such an assembly the cams have the contours shown in Figure 2 while the arms 56 have a moment and disposition as shown in Figure 3. Two of the arms ride on the cam 24 while three are disposed on the cam 31. Also, the individual arms 56 are offset with respect to each other as shown in Figure 1, in order that they may nest and not interfere with each other during rotary operation of the apparatus.

Considering now the pattern of movement imparted to the suckers by the

cams

24 and 31 and the rotation of the driving hub 33. It should be remembered that the cams do not rotate while the driving hub does rotate. Consequently the radially outward directed suckers will have a complex pattern of movement determined by the instantaneous relative movement between the mounting pins and the cam followers. In Figure 5 I have depicted graphically the patterns of movement of the five suckers during one cycle of operation which means one-fifth of a revolution of the shaft 25. Thus, during this cycle the sucker which I have designated by letter A and shown in full lines and which corresponds to the lower right sucker in Figure 2 has a pattern of movement which may be described as a downward dipping movement followed immediately by an upward retracting movement. This is brought about by the severe dwell 24a formed in the cam 24 which has the effect of arresting the rotational movement of the cam follower 57 of the sucker assembly A while the mounting pin 42 of this assembly A approaches its lowermost position. In this manner the normal rotational component of movement of the sucker A during a substantial portion of the rotational cycle of shaft 25 is resolved into radial outward movement of the sucker A when such radial outward movement continues even while the associated cam follower 57 rides radially out of the steep discharge slope of the dwell 24a. Cam 24 is provided with a sharp peak 24b at the discharge end of dwell 24a and immediately upon the follower 57 passing this peak the sucker A is rotated quickly in a counterclockwise direction into the position assumed by the lower central sucker of Figure 2. A succeeding but less severe dwell 24a in the cam 24 restricts the rotation of the outer end of the next preceding sucker B to the relatively small arc shown in- Figure so that it should be understood that the cam mechanism herein providedresults in the consumption of approximately two-fifths of the total rotational time of the shaft 25 and the associated five suckers in carrying each succeeding sucker through the relatively small arc of movement shown in stations A and B of Figure 5'. As will appear later, this feature is of critical importance in the operation of my machine since recycling (idling) time for each sucker is held to a minimum while the working time of each sucker is extended to enable the impartation thereto of deliberate movements and extended suction time to insure dependability in the separation and feeding of the sheets from the pile. 'At stations C, D and E of Figure 5 the radially outward suction cup ends of the sucker assemblies have greatly accelerated rotational components of movement due to the decreasing radius of the cam 24 and the forward extending position of the arms 56, all as graphically depicted in Figure 5, so that the suction cups are returned in minimum time into position available for immediate utilization at the working station A. Of course, the timing of the application of suction to the respective suckers during the complete cycles of movement is highly important and the same will now be described in detail.

Referring back to the parts shown in Figures 3 through 12 it should be observed that while the radial disposition of the apertures 36 in starting gate 35 is. coincident with the radial disposition of the arcuate groove 28 in cam plate 24 and with the apertures 34 in driving hub 33 the circumferential spacing of these apertures 36 is very much closer than the circumferential spacing of the apertures 34. As shown in Figure 8 there. is a small radially extending pin 59 on the periphery of driving hub 33 which is arranged to engage the retractable pin 39 carried by the gate 35 when the pin is in extended position. During oif time pin 39 is arranged to be held in retracted position by a cammed clevis 60 which is carried by the outer face of cam plate 24 in position to engage the shoulder of knob 49 upon the gate 35 being rotated to initial starting position shown in Figure 10 which is allowed by the arcuate slot 30 through which the barrel 38 extends. In this starting position none of the apertures 36 in gate 35 register with the groove 28 so that no suction can be transmitted to any of the apertures 34 inhub 33 and consequently there is no suction applied at this time to any of the sucker assemblies and the plungers thereof are fully retracted by the action of the springs 55 even though the sucker assemblies are rotating at full speed.

It is a remarkable characteristic of this. invention that while the suckers have a predominantly rotary pattern of movement their operative ends (the suction cups) are nevertheless provided with a smooth but quick interruption in rotary movement but simultaneously with a deliberate predominantly linear projective movement coupled with applied suction which is admirably suited to the function of smoothly but firmly affixing the suction cup onto the sheet to be fed. Further, immediately upon the completion of such aifixation the suction cup moves with a predominantly linear retracting movement which again is a superior characteristic in that the connected sheet is positively lifted without crumpling and without any side slipping of the suction cup on the sheet which would tend to break the suction bond. The mechanical contribution to this generally improved operation has been described and a pneumatic contribution for the same will now be explained.

When it is desired to begin feeding and assuming the shaft 25 to be rotating at proper synchronous speed as may be accomplished, incidentally, by a sprocket 61 coupled by a chain, not shown, with the rotating driven parts of a printing press, for example, also not shown, the knob 40 is manually moved oft" the cammed clevis 6 which projects pin 39 into the rotational path of travel of the pin 59 on the driving hub 34 and eventually the pin 59 engages the pin 39 and swings the starting gate 35 around with the hub 33 until the knob 40 rides up onto a second cammed clevis 62 which operates, of course, to move the knob 40 outwardly and consequently to retract the pin 39 from the rotational path of travel of the pin 59. During normal operation the knob 40 is arrested on the clevis 62 but the starting function of the gate 35 as to synchronous application of suction to the successive telescoping suckers is highly important and will accordingly now be explained.

The circumferential positioning of the pin 59 on the hub 33 with respect to the apertures 34 therein is such that as one of the sucker assemblies approaches the station A (Figure 5) the pin 39 is engaged to begin rotation of the gate 35 and almost immediately one or more of the apertures 36 in gate 35 begins to uncover an end portion of groove 28 thereby allowing suction to be applied through the particular aperture 34 which mounts the pin 42 of the sucker assembly which is approaching position A. Upon such assembly reaching the full-line position A this particular aperture 34 is in full communication with the suction groove 28 so'that the plunger 47 of the unit in position A darts out to impress the cup 49 onto the sheet and then retracts in the manner specified above. The same thing occurs as the next succeeding sucker approaches position A as indicated in Figure 11 and the same is also true for the next yet succeeding sucker to approach position A. It should be observed particularly that the radial Webs between the adjacent apertures 36 in the gate 35 prevent the application of suction to the unit next succeeding the first unit to approach and enter the position A after start of the feeding cycle. Upon the gate 35 being sufficiently rotated to ride the knob 40 onto the clevis 62 whereby the pin 39 is retracted the arcuate groove of apertures 36 overlies in circumferential extent the arcuate groove 28 but the apertures 36 are sufiiciently close together to allow open communication between each and all of the apertures 34- in the hub 33 as such apertures transverse their axial alignment with the groove 28. In this manner suction is continuously applied, during normal operation of the apparatus, to two of the sucker units which are transversing stations A and B while suction is withheld from the other three sucker units which are transversing stations or positions C, D and E. However, at the very start of a feeding run suction is applied only to the sucker in position A whereby the individual application of the suckers to the separate initial and successive sheets on the pile is insured. The first sheet on the pile is accordingly subjected to the same handling accorded the next succeeding sheets on the pile. When it is desired to interrupt feeding without shutting down the press or stopping the shaft 25 the same may be accomplished by manually moving the knob 40 from the clevis 62 onto the clevis 60. Such recycling is also done upon a new pile being started.

At the trailing edge of the pile of sheets I provide a pair of air-

blast nozzles

63 and 64, the first of which is fixed and connected with an air supply line 65 while the second of which is carried on a rod 66 for tilting movement about the axis of the rod and is connected to an air supply line 67. Nozzle 64 is arranged to be tilted in proper sequence by a cam 68 keyed onto rotating shaft 69 which is driven through chain 70 from the shaft 25. Of course, if five sucker assemblies 43 are employed the shaft 69 will be driven at five times the speed of the shaft 25 in order that a complete cycle of movement of the nozzle 64 may be imparted during each cycle of movement of a sucker assembly at station A. Nozzle 64 is so mounted and dimensioned that its forward extremity can tilt down closely past the rear edge of a sheet which is being lifted by the sucker at station A and then into engagement with the next lower sheet on the pile. By the timed application of air pressure to the nozzle 64 rapidly moving air is blown under the sheet whose rear edge portion is being lifted by the sucker at station A so that this sheet is lifted and separated from the next lower sheet in the pile while the said next lower sheet is held against movement by the physical engagement of the forward tip of nozzle 64. Air is supplied to the nozzle 63 at about the time the sucker 49 at station A is moving onto engagement with the top sheet on the pile so as to ripple the rear edge portion of this sheet at the time it is being grasped by this sucker and the blast of air from nozzle 63 continues while the sucker is being retracted with the rear edge portion of the top sheet to thereby insure that the sucker picks up only one sheet. The air blast from nozzle 63 continues at least until the tip of nozzle 64 moves down past the edge of the sheet being lifted and air issues therefrom. I provide a rotary distributing valve 70 which is supplied with compressed air by conduit 71' and which has a rotary distributor, not shown, mounted on the end of shaft 69 to time the distribution of compressed air flow into the

conduits

65 and 67 and thus to the

nozzles

63 and 64, respectively.

To insure the stability of the pile and the feeding of but a single sheet at a time I provide a retractable stop 71 at the forward edge of the pile which is pivotally mounted at 72 and which is arranged to be tilted downwardly (retracted) by linkage 73 coupled with a cam follower 74. The latter is arranged to be engaged by a circumferentially limited cam 75 on the shaft so that immediately upon completion of retraction of the sucker at station A and the resumption of rotary movement of this sucker the stop 71 will be let down to allow for forward feeding of the sheet which is being held by this sucker. At this time, of course, the said sheet is being held in an upward floating position with respect to the next lower top sheet on the pile due to the mechanical clamping action of the nozzle 64 and the air blast issuing therefrom so that the forward edge of the sheet being held by the sucker in position A is readily moved laterally over the top of the downwardly tilted stop 71.

To control the pile elevating mechanism 1215 automatically and in such manner that the top sheets of the pile are properly positioned with respect to the operating plungers as well as the stop 71 and the nozzles 63 and 64 I provide a switch 76 which is in the energizing circuit 16 for the solenoid 15 and which is provided with an operating lever 77 engaging the tilting nozzle 64. As illustrated in Figure 2, the operating lever 77 will be moved upwardly a certain extent each time the nozzle tilts forwardly. As sheets are progressively removed from the pile the nozzle 64 will be caused to tilt a progressively greater amount, and similarly the operating lever 77 Will be caused to move upwardly a progressively greater amount. When the pile becomes too low the tilting of the nozzle 64, and consequently the upward movement of the lever 77, becomes abnormally great and the switch 76 is closed. At this time the solenoid 15 is energized to raise the pile by one notch on the rack 12. So long as the pile remains sufficiently high the switch 76 does not close.

As represented in Figure 2 the apparatus of my invention operates upon synchronous rotation of the

shafts

25 and 69 and release of the knob 48 from clevis 60 to separate the sheets from the pile l1 and to feed them laterally (to the left) in overlapped relation in a smooth progression. While one sucker is imparting a final moving force to one sheet a next succeeding sucker is firmly retaining and applying a firm accelerating force to a second sheet and a third succeeding sucker is busily engaged in separating yet another sheet from the pile. Because of this distribution of functioning among multiple sucker assemblies a great number of sheets may be fed in unit time while yet enabling each individual sucker assembly to have relatively slow and smooth movement during their critical functioning stages. This makes for dependability in the functioning of the apparatus and insures a dependable and uninterrupted feed of sheets to the press, for example. Of particular importance is the fact that the sucker assemblies have a predominant rotary motion and any reciprocation involved is only that of minor and low weight components thereof. The general overall result is that the feeder is operative to supply sheets at a much higher rate than has heretofore been possible without sacrifice of dependability.

In the embodiment of the invention shown in Figure 13 the discharge face of the cam dwell (24a) in the cam plate (24') is made steeper than in the case of the cam 24 in the first embodiment in order that there is imparted to the sucker 49 of the sucker assembly 43 while at station A a slight backward movement as shown. As apparent from Figure 13 this may be accomplished without reciprocation of the center of mass of the body portion of the sucker assembly 43 but it does accomplish the purpose of moving the top sheet of the pile 11 in a backward direction represented by the dimension R. This retraction of the sucker attached top sheet is made and the next lower sheet is held clamped by the nozzle 64 and it is effective in separating sheets of certain stock which have a pronounced tendency to stick together.

Having thus described certain representative embodiments of my invention, in which many changes may be made without departing from the spirit or scope of the invention, what I claim as new and desired to secure by Letters Patent is:

1. In a sheet feeder of the type comprising a carrier mounted for rotation about an axis, a plurality of outwardly extending telescopic sucker assemblies mounted on said carrier in circumferentially spaced relation, and means to periodically energize said sucker assemblies to cause the same to become extended; the improvement in said last mentioned means comprising separate passage means in said carrier each communicating with a sucker assembly, a plate adjacent said carrier having an elongated arcuate groove therein adapted for registry with said passage means over a predetermined portion of the circular path thereof, the arrangement being such that said separate passage means are successively brought into communication with said groove and whereby at all times more than one of said separate passage means is in communication with said groove, and a starting gate comprising a flat plate rotatable about said axis and positioned in fiat lying relation between said carrier and cam plate, said starting gate having a plurality of closely spaced apertures adapted to be brought into progressive registry with said arcuate groove upon rotation of the starting gate about said axis.

2. Apparatus according to claim 1 further including a retractible pin on said starting gate and a projection on said carrier whereby rotation of said carrier may rotatably move said starting gate, and means on said cam plate to automatically retract said pin away from said projection to thus limit the rotation of said starting gate without impeding the continued rotation of said carrier.

3. In a sheet feeder a plurality of telescoping suckers each of the kind having a plunger mounting a suction cup at its outer free end which moves outwardly upon the application of suction until a sheet is engaged to close oif the suction cup whereupon the plunger and suction cup are retracted inwardly, means mounting said suckers in circumferentially spaced and radially outward extending pattern and for rotating the same in the common plane both about a common centrally disposed axis and about individual axes positioned radially outward from but parallel to said common axes whereby said suction cups move with a predetermined pattern of circumferential speed while having a superimposed predetermined pattern of radial outward and inward movement as determined by the application of suction to the successive suckers approaching a certain fixed station and the engagement of the suction cups with successive sheets to be fed from a pile, said predetermined pattern of circumferential speed of successive suckers being substantially arrested independently of the movement of the other suckers as the successive suckers pass said fixed station, the arrangement being such that the suction cups of said suckers are substantially stationary for an interval of time wherein a sheet is engaged.

4. Apparatus according to claim 3 further including cam means to control the rotation of said suckers about said individual axes, said cam means being formed to substantially arrest the circumferential component of movement of the suction cups of successive suckers at a certain station and for a substantial interval of time and to closely space the next preceding sucker while imparting a decreased circumferential speed to the suction cup thereof, said cam means being also formed to impart an increased circumferential speed to the suction cups of the other suckers in bringing the same around to said certain station.

5. Apparatus according to claim 4 further including means to apply suction to said telescoping suckers during a predetermined fixed portion of the path of travel about said common axis.

6. In a sheet feeder having a plurality of telescoping suckers each having a plunger mounting a suction cup at its outer free end and operative automatically in response to the application of suction to impart an outward movement to said plunger and cup until said cup is closed by impingement on a sheet after which the plunger and cup are retracted, a carrier for moving said suckers laterally and in one direction only onto a pile of sheets from over one edge thereof with the cups thereof directed to the top surfaces of the sheets of the pile, means associated with said carrier to move said suckers through a predetermined pattern of movement wherein each of said cups have the lateral movement thereof arrested independently of the other cups for a predetermined interval of time while it moves into impingement with the sheet and retracts the sheet upwardly, and means to apply suction to said suckers during a predetermined portion of the pattern of movement of the successive suckers.

7. In a sheet feeder of the type adapted to feed a plurality of'sheets in successive overlapped relation from a pile thereof the combination of a carrier positioned over the rear edge of said pile and adapted for movement in the direction of feed, a plurality of suckers mounted on said carrier and extending outwardly thereof and adapted when in a predetermined position for engagement with the rear edge portion of a sheet positioned on said pile, means to move said carrier to impart movement to said suckers in said direction of feed whereby said plurality thereof are caused to move successively into said predetermined position, and means operative when one of said suckers moves into said predetermined position to substantially arrest the movement thereof in said direction of feed independently of the movement of the other suckers.

8. Apparatus according to claim 7 further including means operative subsequent to said one sucker moving into said predetermined position and engaging a sheet and while the next subsequent sucker is moving into said predetermined position to effect movement of said one sucker in a feeding direction at a reduced speed for a predetermined interval of time.

9. Apparatus according to claim 8 further including means operative after said predetermined interval of time to impart a substantially increased speed to said one sucker to cause the same to move rapidly toward said predetermined position.

E2 10. In a sheet feeder of the type adapted to feed a plurality of sheets in successive overlapped relation from a pile thereof and comprised of a plurality of sheet-engaging,

terval of time as said members individually move into sheet-engaging position, and control means for initiating operation of said feeder, said control means being operative to initially energize only one of said sheet-engaging members and then the member next moving into sheetengaging position and thereafter two or more members simultaneously.

11. In a sheet feeder of the type adapted to feed a plurality of sheets in successive overlapped relation from a pile thereof the combination of a carrier positioned over the rear edge of said pile and adapted for rotation about an axis disposed transversely to the direction of feed, a plurality of suckers mounted on said carrier and extending outwardly thereof and adapted when in a predetermined position for engagement with the rear edge portion of a sheet positioned on said pile, means to rotate said carrier to impart rotary movement to said suckers whereby said plurality thereof are caused to move successively into said predetermined position, and means operative when one of said suckers moves into said predetermined position to substantially arrest the rotary movement thereof independently of the movement of the other suckers.

12. In a sheet feeder of the type adapted to feed a plurality of sheets in successive overlapped relation from a pile thereof the combination of a carrier positioned over the rear edge of said pile and adapted for movement in the direction of feed, a plurality of successively disposed suckers mounted on said carrier in depending relation over the rear edge portion of the pile and adapted when in a predetermined position to individually engage the rear edge portions of successive sheets positioned on said pile, means to move said carrier to impart general movement of said suckers in said direction of feed whereby said successive sheets are moved in said direction of feed, means operative to substantially arrest the feeding movement to said suckers in said direction of feed Wheresaid predetermined position to provide time for the attachment of the individual suckers to the successive sheets, and means to energize said suckers during the time their feeding movement is arrested and during a predetermined following path of movement whereby during the time while one sucker is attaching itself to a sheet the next preceding sucker is forcibly moving the next preceding sheet in a feeding direction.

References flirted in the file of this patent UNITED STATES PATENTS 622,106 Berry Mar. 28, 1899 1,366,549 Winkley June 25, 1921 1,706,952 Broadrneyer Mar. 26, 1929 2,085,612 Spiess June 29, 1937 2,156,648 Baker et al. May 2, 1939 2,195,545 Stobb Apr. 2, 1940 2,341,521 Baker et al. Feb. 15, 1944 2,395,497 Nordquist Feb. 26, 1946 2,566,175 Danielsson Aug. 28, 1951 2,568,069 Herr Sept. 18, 1951 2,600,138 Tesch June 10, 1952