US2698175A - Sheet feeding mechanism - Google Patents

Description

Dec. 28, 1954 e. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 1 INVENTOR. 650265 5. POWELL m EF SMAWA ATT6EN'EY6 Dec. 28, 1954 5, ROWELL 2,698,17

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 2 INVENTOR. GEO/FM J. Wok/ LL AWOWEVKS.

Dec. 28, 1954 G. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 3 INVENTOR. 450M: 5. 2044 54 Dec. 1954 G. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 4 INVEN TOR. 22 Mme: .s. wwaL Dec. 28, 1954 G. S. ROWELL SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 SheefcsSheet 5 INVENTOR. 65026.6 5 POWELL 9770MB K5 Dec, 28, 1954 G. s. ROWELL, 2,698,W5

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 6 i I l I i I I 42 I I06 I J22 WIL- 1 loz i" as: 5 E

E fig a amz/ INVENTOR. QED/F61 6. IPOWZLL BY m q [@WJM ATTOk/V'E V6 United States Patent SHEET FEEDING MECHANISM George S. Rowell, Bedford, Ohio, assignor to The Chandler & Price Company, Cleveland, Ohio, a corporation of Ohio 14 Claims. (Cl. 271-11) This invention relates as indicated to sheet feeding mechanism for printing presses and the like and particularly for cylinder printing presses.

There has been a steadily increasing need for a small cylinder printing press of compact design having the adaptability required for use by jobbers. Such a press must be rapid in operation and versatile in the sizes and types of sheets which may be printed without elaborate adjustment of the sheet feeding mechanism. The sheet feeding mechanism of this invention may be employed in conjunction with various other devices such as folding machines but is especially adapted for use in cylinder presses of the type above indicated.

It is, therefore, a primary object of this invention to provide sheet feeding means capable of fast operation without necessity of an overlapping feed, thereby permitting the feed table to be positioned more closely to the impression cylinder with a resulting saving in space.

Another object is to provide sheet registering means which will be effective under conditions of high speed operation and very accurate.

A further object of this invention is to provide sheet feeding mechanism in which the same means which picks up the sheet from the feed table feeds such sheet directly to the impression cylinder without requiring any intermediate conveying means.

Still another object is to provide stack hold down and air blast means adapted to cooperate with such rapidly operating sheet feeding mechanism.

Other objects of this invention will appear asthe description proceeds. To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a top plan view of a printing press constructed in accordance with my invention showing the feed table, sheet feeding and registering mechanism and the impression cylinder;

Fig. 2 is a front elevational view of such press;

Fig. 3 is a vertical sectional view taken along the line 3-3 on Fig. l and showing the suction means of the.

sheet feeding mechanism in position to seize a sheet on the stack;

Fig. 4 is a similar sectional view but showing a position of such sheet feeding mechanism after it has advanced a sheet to the impression cylinder;

Fig. 5 is a top plan view of one of the sucker fingers extending from a fragmentary portion of the sucker bar; Fig. 6 is a sectional view taken along the line 6-6 on Fig. 5;

Fig. 7 is a view similar to Fig. 6 but showing the along the line 8-8 on Fig. 5; Fig. 9 is a fragmentary sectional view of the sucker bar mounting taken along the line 9-9 on Fig. 4;

Fig. 10 is an elevational view of the mounting of the "forward register;

Fig. 11 is a sectional view of such mounting means taken along theline 11-11 on Fig. 10;

2,698,175 Patented Dec. 28, 1954 12 is a vertical sectional view similar to Fig. 3 but illustrating a modified form of sucker bar mounting means;

Fig. 13 is a fragmentary view of the sheet feeding mechanism of Fig. 12 in the course of elevating a sheet from the stack;

Fig. 14 is a fragmentary view showing the positions of the parts after release of the sheet by the sucker tips;

Fig. 15 is a fragmentary top plan view of the sucker bar mounting means shown in Figs. 12-14;

Fig. 16 is a fragmentary front elevational view of such mountmg means;

Fig. 17 is a fragmentary top plan view of another modified form of such mounting means;

Fig. 18 is a vertical sectional view corresponding to a mirror mage of Fig. 3 but illustrating the cylinder press gmpltlaymg feeding mechanism of the type illustrated in Fig. 19 is a vertical sectional view taken along the line 19-19 on Fig. 18;

Fig. 20 is a sectional view taken along the line 20-20 on Fig. 18;

Fig. 21 is an elevational view of the side registering means showing a sheet being engaged thereby; and

Fig. 22 is an end elevational view of the sheet registering means of Fig. 21. Referring now more particularly to said annexed drawlngs and especially Figs. 1-4 inclusive, one form of press in which I contemplate employing my new sheet feeding mechanism comprises side frame members 1 and 2 reinforced by cross brace 3. Between such frame members is positioned a feed table 4 of conventional design adapted to support a stack of sheets 5 and provided with side gauges 6 and 7. Longitudinal slots 8, 9 and 10 are provided for gauges for the rear edge of such stack, only one gauge 11 being required for the size of stack illustrated in Figs. 1 and 2. The usual stack elevating means (not shown) will be employed operative to elevate the feed table and stack as sheets are withdrawn from the top of such a stack. Y

A back plate 12 is provided against which the forward side of the stack is adapted to rest, such plate having a number of slots 13 in its upper edge through which air from the air blast means may be emitted.

Journaled in the side frame members 1 and 2 is the impression cylinder 14 which is adapted to be driven through gear 15. Feed plate 16 extends between such cylinder and the forward edge of the stack. Adjacent the forward edge of the stack such feed plate is flanged downwardly, such flange 17 being slightly spaced from back plate 12. Fitted in such intervening space is a freely slidable hold down means comprising a metal sheet, the upper edge of which is bent into a depending flange 18 adapted to rest upon the forward edge of the stack. The metal sheet forming such hold down means is provided with openings corresponding to openings 13 in back plate 12 so that the air blast from longitudinal chamber 19 under feed plate 16 is permitted to reach the forward edge of the stack. A second parallel chamber 20 is provided under feed plate 16 adapted to direct a blast upwardly through openings 21 for the purpose to be described below.

The sheet feeding mechanism is reciprocated through the oscillation of'rocker arm 22 about its pivotal mount 23. Such rocking or oscillation of arm 22 is accomplished through'the following means. A gear 24 driven with impression cylinder 14 meshes with gear 25 to drive a sprocket 26 connected by chain drive 27 with sprocket 28. Sprocket 28 drives a large cam 29 which also has a cam track 30 slotted in its outer face. Adjusting arm 31 may be locked by means of lock nuts 32 and 33 in desired position to urge idlerroller 34 against endless chain 27, thereby maintaining the proper degree of tension in the latter. Rocker arm 22 is provided with a cam roller 35 traveling in cam track 30, whereby such rocker arm will be oscillated back and forth as cam 29 revolves.

A guide-way 36, having a longitudinal slot 37 therein, is pivotally mounted at 38 in a side bracket 39 in turn pivotally mounted onside frame 2 at 40. An adjusting screw 41, passing through bracket 39 and bearing on ,feedplate 16, is operative to adjust-ably tilt bracket 39 to the right. relieved in local areas to permit the advance'of the-sucker t1ps,- and the individual segments of which such'roll is #comprised maybe moved'along shaft" 74 into anyd'esired about its mounting 40 and thereby to effect a delicate adjustmftt' of' the-location of' pivotal mounting 38' ofguideway Referring now additionally to Fig. 9 of the drawing, the end *of :tubular sucker ba'r 42 is provided with an offset-brace arm"43, both: such a'rms having ball bearing journaled rollers 44 and 45 respectively adapted to''- travel insl'ot 37 of guide-way 36. Also pivotally connected to the endof sucker bar'42 is' 'a -1ink'46 connected to he upper end of rocker arm 22. The other 'erid of guideiway -36- fr'om its pivotal F mount 38 carries I a I cam- 'roller 47' adapted to 'run on the periphery of canrZQ. The coil spring '48 serves-to maintain s'uch'roller in close engagement with such cam. -As' shown in' Figs. 1 and :2,the oth'er end of sucker bar 42 is supported and oscil lated by means which are the exact mirror image of the means above des'cribed'and illustrated in Figs. 3 and 4; shaft 49 driven by gear 25 servingto synchronously drive the =sprocket corresponding'to' sprocket 26"on-the other side -'of'-the press. Like' numerals will, therefore,- be employed to designatelike parts of such mechanism.

Now referring to Figs. 1 and -8 of the drawing; tubular sucker bar 42, which-'is olosed ateachend, is provided with a flexible hose connection 50=leading to a suction "pump cn'ot shown). such' sucker bar-carries a plurality of fingers, the construction of whichis best illustrated in Figs. 5+8. Each -finger comprises a tube 51 extending laterally forward from "within-such s'ucker bar in 1 which is sleeved a 'protr-uding tube 52 closed at each end. Tubular extension 51 -is slotted-near its ex- -tremity -and provided' with-wings"53 and 54, whereby tube -52 -'may be tightly clamped by adjustment of knurled screw 55. A sucker tip 56, preferably of 'rubber, is -inounted at rightangles to theend of tube SZ-a'nd cOm- *municates -with the *interior thereof. An opening 57 1s provided in the lowerwallof tubular extension 5l' within sucker bar' 42 and a similar opening "5815 provided in thewall of tube 52 adapted'to coincide-with such firstnamed opening When'sucker tip 56 is turned downwardly. as s hown in'Fig. 6, andnot to socoincidewhen such suckertip'is turned upwardly, as shown-in Fig. 7. It will, therefore, be seenthat a sle'eve 'valve has-'been provided whereby thesucker tip is in communication with the interior of sucker bar 42 when such -su'cker tip 13 tul'ned downwardly injposition to-contact the 'topmo st "-sheet' of the stack but which wilhplacesuch sucker tip out of communication with the-interior of 'the 'su'ckerbar when such sucker tipis 'turned upwardly'as shown-an Fig. 7. In operation,-as 'shown'in Fig. 1, only those sucker-tips adapted to contact the sizegof sheetbelng fed will beturned downwardly with the 'others'turned up to close off communication with the-suckerb'ar as WeIl 'as 'toavoidpossibility of interference with theside register described I below.

The forward register is in the form of a long-comb'59 having depending fingers 60. As best-'shown in Figs. 1, '3, and 11, 'such register is clamped to rocker-shaft 61 journaledinside frames 1 and 2bymeans of clamps 62 and 63. 'As shown -in Fig. l1,' each of these clamps.

- comprisesa 'split'bushing adapted to'be drawn into tight engagernent with sha'ft'61 by means of scr'ewl 64. The register is-attached thereto by bolt 65 and bac'ked by a coil spring 66, whereby damage to the mechanism will be prevented should such register accidentally contact otherparts of the me'chanisnwin operation. A5 fbest shown in Figs. 1 and 3, the end-of:'shaft 6l protrtlding "through side frame member l carries*aishortt'leverlarm 1 and cam roller 67 1 adapted: 'to" ride the periphery of cam #68 driven with the impressionz-cylinder 14. A=?torsion. spring 69'acts"on SUch deVer -arm to hold -rdlle1f-:67Hin close contact-with-the periphery of cam-'68. vSuch cam 'isshaped to rock shaft 61 back and' forth to 'swing1 for- =ward f register 59- in and out i of operative position.

A'zpulley 70 drivenwith"cam 68 "is" adaptedto be'connected' to smaller pulley 71' by means of a V-belt" (-not *shown). Pulley 7l -isadaptedito drive sp'ur gear' 'lz,

"which in turn drives gear' 73 and shaft" 74. Mounted *on "shaft 74"forro'ta'tion therewith is a'ro1l 75-bearing'a ":spiral r1b'76-"about its periphery,}pr'eferably ofrubber. ."As shown in the drawing; when"'roll75 is rotated in the 'directionillustrated in Fig. 3, such spiraljwill 'rnove Roll 75 is interrupted or circumferentially position. As best shown in Figs. 21 and 22, the side register comprises a small 'vertical flange '77 carried on a laterally adjustable plate member 78 which may be locked in desired position "by means of nut 79 threaded on stud 80.

The operation of my.new sheet feeding mechanism is as follows. Slot 37 is so shaped that as rocker arm 22 swings rearwardly, the sucker bar 42 and the sucker tips carried thereby will be rocked in counter-clockwise l0 direction, asviewed in Fig. 3. At the same time roller 47 encounters depression 81 in the periphery of cam 29 thereby tilting guide-way 36 abruptly to lower the sucker tips into engagement with the forward portion-of the topmost sheet of the stack as illustrated in Fig. 3. At this point, the air blast from chamber 19 comes on tending to fluff up and separate the uppermost sheets of the stack. Thesuctionthen comes on in such sucker bar and the sucker tips seize the sheet. Rocker arm 22 cont'inues its rearward movement for a short distance sufficient to wiithdrawlheforward edge of the sheet' from beneath hold down 18. Simultaneouslyroller 47-encounters theabruptxshoulder on cam '29 succeeding depression sl :and. abruptly elevates/guide-way36 and the sucker bar and "sheet carried thereby. .As rocker arm l22now swings forward,' the.upward turn of slot-'37 causes the-sucker tips. andltherefore the: leading edge of the sheet to-"beslightly tupwardly'inclinedcausing such edge to :planethrough the air"without drooping. The degree of isuch inclination may be regulated by adjusting screw "41 'even 'to a point oflafl'ording no inclination whatsoever if desired. As the sucker'tipsapproach the forward limit 'of their movement between"the'segments of'roll 75 with the forward edgeof the sheet extending between "the --lower- 'surface 'of-Y'such rolland the surface of'feed plate 30 16;the suction is'turned'off and the sheet released. "At

-thispoint,ithe air iblast from chamber 20 through open- -ings21icomes on causing the sheet tobe pressed upwardly 'against the spiral ribs 'ofrevolving roll75. Si-

multaneously with the foregoing; roller 67 riding on cam f68 has'rocked shaft fl' to swing" forward register fingers 60 down into'gauging position. The rotation of roll' 75 'bringsthe forward edge of the sheet into gauging engagement 'with such fingers and at the same time the movement of the spiral ribs 76 to theri'ght carries the 40 fioatingi'sheet into 'gauging engagement with side reg- Tister 77. Because-"of the fact that-the sucker tips have already carried the sheet so close to the'impression cylinder,1there is: little loss"of register between the stack and the above described registering means so' that only slight 5oad ustment of the-sheet need beetfe'cted if thestack has beenprop'erly positioned upon the feed table. "Register ifingers-60 now 'swing back again'and sheet grippers 82 of theimpression cylinder seize the forward edge of the sheet. Rocker-arm 22 is'now swinging'rearwardly again and' 'the operation=is repeated. Ithas been found that sheet feeding mechanism of the typedescribed is capable of exceedingly rapid operation and, indeed, itis believed that for the first time sheet feeding means has beenprovidedcapable' of feeding individualsheets from a stack at'a rate comparable to that at which a press of this type may be effectivcly'run. Thus, the speed of operation of the sheet feeding mechanism is no-longer "the limiting factor-in'the operation of the press as has been '-'the casein the' past. "The same sheet may be run through the'press as many as seven-times without apparentloss "of register.

Figs. 12-16 illustrate a modified form of my new sh'e'et feeding mechanism in which 'the' guide-way for the sucker bariniits'reciporcation isnot adaptedto be tilted but is fixedly attached ateach end to side frame member 2. As the driving'rneans' and registering means are the s'ame" as in the first embodiment of my invention above described, like pa'rts will be designated by like numerals.

Means for controlling the rotative movement of the 'lfi sucker bar about its axis is provided, however, on but one "side of =thepress as such means is sufficiently positivein its effect not to require duplication.

A straighh'guide-way 83 in 'the form of a tubular bracket is rigidly attached to'- sideframe member 2 and s'upportsa slide'84' sleeved thereon in which one end of sucker bar'42 is inounted for pivotal movement about -its-a'xis. "Such slide' 84'is also'pivotally connected by means of link 85 to the upper end of rockerarm 22 so -that as such arm- 22 is oscillated by rotation of cam 85 86, slide 84 and Sucker-bar 42will be reciprocated along guide-way 83. Mounted on the end of sucker bar 42 for rotation therewith is a bracket member having arms 87 and 88 extending therefrom approximately at right angles to each other. Arm 87 is adapted to contact the under surface of an eccentric 89 mounted on slide 84 thereby limiting clockwise rotation of sucker bar 42 as viewed in Fig. 12. A delicate adjustment of the degree of such clockwise rotation is obtainable by turning such eccentric.

The other, upwardly extending, arm 88 carries a cam roller 90 at its end adapted to engage the under surface of arm 91 pivotally mounted at 92 about guide-way 83 on side frame member 2. Integral with such finger 91 is another inner finger 93 carrying an upwardly extending bolt 94 which passes freely through a boss 95 on side frame member 2. A spring 96 between boss 95 and arm 93 tends to urge such arm downwardly to the extent permitted by nut 97. Upward pressure on such arm will, of course, result in compression of spring 96 and upward movement of bolt 94 through boss 95. The lower surface of arm 91 contacting roller 90 provides a cam track having a shoulder 98 succeeded by a depression 99. A spring 100 serves to maintain roller 90 in close engagement with the under surface of arm 91.

In operation, as rocker arm 22 swings to the right, as viewed in Fig. 12, roller 90 encounters shoulder 98 causing sucker bar 42 to be rotated in a counter-clockwise direction and bringing the sucker tips into contact with the top of the stack. Just prior to such contact, the air blast from longitudinal chamber 19 has been turned on to fluff up the forward portion of the stack. As rocker arm 22 swings still further to the right, the sucker tips, now grasping the sheet, are caused to withdraw the same from beneath the lip of hold down 18. During such movement roller 90 passes shoulder 98 and depression 99. Thereupon, sucker bar 42 is rotated abruptly in a clockwise direction and the sucker tips elevated with a snap action to raise the forward portion of the sheet as shown in Fig. 13. Rocker arm 22 is now swung to the left as cam 86 continues to turn, moving slide 84 to the left along guide-way 83. Stop 89 limits the rotation of sucker bar 42 in a clockwise direction so cam roller 90 is effective to push up arm 91 as it passes prominence 98. After the sucker tips have advanced between the segments of roll 75, the sheet is released for registering as shown in Fig. 14. The sheet feeding mechanism then repeats the cycle, the sheet being registered and seized by impression cylinder grippers 82 in the same manner as previously explained.

A modified embodiment of the mechanism of my invention is illustrated in Figs. 17-20 where guide-way 101 is mounted on studs 102 and 103 carried by bracket plates 104 respectively welded to side frame members 1 and 2. Sucker bar 42, here of rectangular cross section as shown in Fig. 18, is pivotally connected at each end by means of pins 105 to slides 106 adapted to be reciprocated along such guide-ways 101. Arms 107 extending forwardly from such sucker bar are connected to brackets 108 on such slides by means of tension springs 109. The means for reciprocating slides 106 along guideways 101 are substantially identical with that previously illustrated and described and the parts are accordingly identified by like numerals. A slightly different form of device for maintaining chain 27 in tight engagement with the sprockets is, however, shown comprising an idler wheel 110 carried at the end of threaded rod 111 adapted to be locked in adjusted position relative to lower frame member 114 by means of nuts 112 and 113.

As best shown in Figs. 18 and 19, the left-hand end of sucker bar 42 carries an upwardly extending lever arm 115 bearing a cam roller 116 at its upper end, such lever arm corresponding generally to lever arm 88 of the Fig. 12 embodiment. Pivotally mounted on boss 117 is a slotted arm 118 carrying on its lower surface a cam track member 119 adjustable longitudinally along such slot and adapted to be retained in desired position by means of screw 120. The action of springs 109 serves to hold roller 116 in close contact with such cam track 119. Limiting the degree to which such springs are effective to rotate sucker bar 42 in a counter-clockwise direction, as viewed in Fig. 18, is an adjustable screw 124 fastened in arm 118 extends upwardly through an aperture in bracket 123 and carries an adjusting nut 125 threaded thereon. Between such nut and such bracket about such pin is a compression spring 126. It will, therefore, be seen that by turning such nut to compress such spring, the pressure urging arm 118 and therefore cam track 119- downwardly into engagement with roller 116 may be regulated as desired, a cotter pin 127 preventing pin 124 from being drawn through the aperture in bracket 123. t

The operation of this last-described embodiment of my invention is substantially that of the embodiment shown in Figs. 12-16. However, after seating cam track 119 in the proper position, the angle at which the advancing sucker tips will carry the sheet may be regulated by adjusting screw 121 so that the forward edge of very thin sheets of paper may be rather sharply upwardly inclined, whereas heavier and stiffer sheets will be given a relatively small degree of inclination, the rectangular cross section of sucker bar 42 affording a sufficient degree of clearance. In Figs. 17 and 18, the ribbed register roll 75 is shown driven directly by means of-a belt 128 and a pulley 129 instead of through the pulley and gear train as shown in Fig. 1. Its operation is, however, identical.

It will be seen from the foregoing that I have provided new sheet feeding mechanism which is adapted for very rapid operation and may be readily adjusted to accommodate either heavy or light sheets. Since as little as 2% inches may intervene between the forward edge of the stack and the point where the grippers on the impression cylinder seize the forward edge of the sheet, it is obvious that the press may be of -very compact construction, a matter of some importance to small jobbers and the like. Because of the small distance between the stack and the impression cylinder, sheets may be fed as rapidly as the press may otherwise be run without the complexity of lapped feeding usually required when operating presses at high speeds. Despite such high speed operation, exceedingly accurate register is obtained due partly to the short distance and positive control over the sheet being advanced and partly to my novel register means which quickly performs any final slight adjustment in the position of the sheet required before such sheet is snatched by the gripper means on the impression cylinder.

This application is a division of my co-pending application Serial No. 696,992, filed September 14,1946, now abandoned.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In sheet feeding mechanism, suction means operative to seize and advance the topmost sheet of a stack, a guide-way for said suction means as it thus advances, means operative to tilt 'said guide-way during such advance, and means operative to tilt said suction means relative to said guide-way during such advance.

2. In sheet feeding mechanism, suction means operative to seize and advance the topmost sheet of a stack, a guide-way for said suction means as it thus advances, means operative to tilt said guide-way to elevate said suction means during such advance, and means operative to tilt said suction means relative to said guide-way during such advance.

3. In sheet feeding mechanism, suction means operative to seize the topmost sheet of a stack adjacent its forward edge and advance the same, a guide-way for said suction means as it thus advances, means operative toelevate said guide-way to elevate said suction means during such advance, and means operative to tilt said suction means relative to said guide-way to upwardly incline the forward edge of such sheet during such advance.

4. In sheet feeding mechanism, suction means operative to seize the topmost sheet of a stack adjacent its forward edge and advance the same, a guide'way for said suction means as it thus advances pivotally mounted for oscillation in a vertical plane, cam means operative to tilt said guide-way about such pivotal mounting to elevate said suction means during such advance, and cam means operative to tilt said suction means relative 57 ,to said guideway to upwardly ,inclinethe forward edge ,of-such sheetduring such advance.

,5. In sheet feeding mechanism, suction means operativeto. seize and advance the topmost sheet of a stack comprising a horizontal pivotally mounted sucker bar, ztubular arms extending therefrom over such stack, sucker tips-rigidly fixed to thefree ends of said arms adapted .toengage the upper surface of such stack, and a lever ,arm on said pivotally mounted sucker bar; a guide-way inclined relative to such stack along which said sucker bar; is adapted to be laterally reciprocated; and means ,operative on said lever arm to rock said sucker bar abruptly-to elevate said sucker tips immediately after seizing such-sheet to elevate such sheet from such stack.

6.-In sheet, feeding mechanism, suction means opera- :tive to seize and advance the topmost sheet of a stack comprising a horizontal pivotally mounted sucker bar, tubjular arms extending therefrom over such stack, sucker tips rigidly fixed to the free ends of said arms adapted to engage the upper surface of such stack, and a lever arm onsaid pivotally mounted sucker bar; a guide-way along 'which said sucker bar, is adapted to be laterally reciprocated; means operative on said lever arm to rock said sucker-bar abruptly to elevatesaid sucker tips immediately after seizing such sheet, and a stop adapted tolimit the degree of elevation of said sucker tips.

7.--In sheet'feeding mechanism, suction means opera- --tive to seize and advance the topmost sheet of a stack comprising a horizontal pivotally mounted sucker bar, tubular arms extending therefrom over such stack, sucker tips rigidly fixed to the free ends of said arms adapted tov engage the upper surface of such stack, and a lever .:arm on said pivotally mounted sucker bar; a guide-way .-along which said sucker bar is adapted to be laterally -reciprocated; a roller on the end of said lever arm; a v

cam track resiliently engaging said roller; resilient means urging said roller into engagement with said track a shoulder .on said track adapted to rock said lever arm and sucker baras said sucker bar is reciprocated in one direction, whereby said sucker tips will be depressed into engagement with the top of such stack; a recess in said track beyond said shoulder adapted to permit said lever arm and sucker bar to rock abruptly to elevate =said sucker tips upon further reciprocation in the same direction; and a stop limiting the degree of elevation of said sucker tips upon reciprocation past said shoulder in the opposite direction.

8. In sheet feeding mechanism, means operative to seize and advance the topmost sheet of a stack comprising apivotally mounted carriage and suction means rigid- 1y fixed to and disposed forwardly of said carriage; a guideway along which said carriage is adapted to be reciprocated; means for rocking said carriage comprising a lever arm fixed thereto, a cam roller on said lever arm, a resiliently backed cam track adapted to engage said 'roller, resisient means urging said roller into engagement with said track, a shoulder on said cam track adapt- .ed to rock said lever to depress said suction means as said carriage is reciprocated in one direction, and a .stop adapted to limit the degree of elevation of said suction means upon reciprocation of said carriage in the opposite direction.

9.-Insheetfeeding mechanism, means operative to seize and advance the top-most sheet of a stack comprising a pivotally mounted carriage and suction means rigidly fixed to and disposed forwardly of said carriage, a guide-way along which said carriage is adapted to be reciprocated, a lever arm fixed to said carriage, means operative to rock said lever arm to depress said suction means into engagement with the top-most sheet of such stack, andmeans operative to rock said lever arm abruptly to elevate said suction means immediately after seizing such sheet.

10. In'sheet feeding mechanism, means operative to -seize and advance the top-most sheet of a stack com-.

prising a horizontal pivotally mounted sucker bar, tu-

bular arms extending therefrom over such stack, sucker -tips rigidly fixed to the ends of said arms adapted to engage the upper surface of such stack, and a lever zarm on said pivotally mounted sucker bar; a guide-way along which said sucker bar is adapted to be reciprocated; ;,a -cam-roller on the end of said lever arm, a cam track resiliently engaging said roller, resilient means urging i said roller-into engagement with said cam track, a shoulder onpsaid cam track adapted to rock said leverv arm vandspckerbar, as'the latter is reciprocated in onedirection and thereby depress-said suckertips intoengagementtwith the top of such.stack, a recess insaid camtr'ack beyond said shoulder adapted to permit said lever; arm and sucker bar to rockabruptly to elevate said. sucker tips upon further reciprocation of said sucker .bar -m the .same direction; astop limiting the degree of.elevati0n press or the like which comprises subjecting the forward .edge of a stack of'sheets to a blast of air and themedvancing the top-most sheet, thesteps of yieldably-holding down the forward edge portion of such stackof sheets, moving the top-most sheet rearwardly to free the forward edge thereof, then abruptly elevating .the portion of such sheet adjacent the forward edgecthereof and advancing the same.

12. In the method of feeding sheets to a printingpress or the like which comprises subjecting the forwardedge of a stack of sheets tea-blast of air and then.advancing the top-most sheet, the steps of yieldably holding down the forward edge portion of such stack of sheets, moving the top-most sheet rearwardly to free the forward edge thereof, then abruptly elevating the portion of such sheet adjacent the forward edge thereof and advancing the same, and upwardly inclining the forward portion of such advancing sheet.

13. In sheet feedingmechanism, means operative to seize and advance the top-most sheet of a stack comprismounted to rock said sucker tips intoand outof stackvengaging position, resilientmeans urging said suckertips upwardly, and cam means adaptedto rock said carriage to depress said sucker tips into stack-engaging position against the action of said resilient means during v rearward movement of said carriage and then to release said carriage for abrupt upward movement of said suckergtips under the. infiuencelof said resilient means prior to-the next forward movement of said carriage.

14. In sheetfeeding mechanism, means operative to seize and advance thetop-most sheet of.a stack comprising a carriage and suction means rigidly fixed toand disposed forwardly of. said carriage, a guide-wayalong which said carriage is adapted to be reciprocated to move said suction means from a position abovesuch stack to a position forwardly thereof, said carriage being pivotally mounted to rock said suction means .into and out of stack-engaging position, means adapted .to rock said carriage to depress said suction means into stack-engaging position during rearward movement of References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 488,212 ,Masterson Dec. 20,1892 824,920 Erickson July 3, 1906 1,133,807 Lagerman et al Mar. 30, 1915 1,207,365 Broadmeyer Dec. 5, 1916 1,435,205 'Brigham Nov. 22, 1922 1,488,673 Henderson Apr. 1,1924 1,625,578 Tremper Apr. 19, 1927 1,834,382 Cheshire Dec. 1, 1931 1,867,038 Upham July 12, 1932 1,966,320 Tate July 10, 1934 2,097,587 Dearing Nov. 2, 1937 2,132,283 -Allen Oct. v4, .1938

2,169,400 Strongberg et a1 Aug. 15, 1939 2,182,435 Huck Dec. 5,' 1939 2,207,492 Speiss July-,9; 19,40

:(Otlwr references onlfollowing ,page) Number Name Date Seybold Sept. 10, 1940 Christensen Aug. 26, 1941 Sundstrand May 12, 1942 Robinson Feb. 16, 1943 Lake et a1 June 6, 1944 Bernard et a1 Apr. 24, 1945 Number Number 10 Name Date Eckman Aug. 14, 1945 Perry June 18, 1946 Williams Jan. 13, 1948 FOREIGN PATENTS Country Date Germany July 10, 1930

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