US1717503A - Sheet-feeding mechanism - Google Patents

Description

June 18, 1929. c, FRAUENBERGER 1,717,503

SHEET FEEDING MECHANISM Filed Nov. 16, 1927 e Sheets-Sheet i June 1929- c. F. FRAUENBERGER SHEET FEEDING MECHANISM Filed NOV. 16, 1927 6 Sheets-Sheet 2 Zw/ffamw/ayw @51 1): Etta/4M3 Y (7 a. dywvmm June c. F. FRAUENBERGER SHEET FEEDING MEGHANI SM Filed Nov. 16, 1927 6 Sheets-Sheet m m w m 5 6:11! fjazwm/m av 35 14: flbtome/u June 1929- 'c. F. FRAUENBERGER SHEET FEEDING MECHANISM Filed Nov. 16

1927 6 Sheets-Sheet 4 smoonto'z June 18, 1929.

C. F. FRAU ENBERG ER SHEET FEEDI NG MECHANISM Filed Nov. 16, 1927 6 Sheets-Sheet 5 Z Suva a M 545M c. F. FRAUENBERGER 1.717.503

SHEET FEEDING MECHANISM Filed Nov. 16, 1927 6 Sheets-Sheet 6 June 18, 1929.

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Patented June 18, 1929.

UNITED STATES rinses PATENT OFFICE.

cam. r. FRAUENBERGER, or FRANKLIN, MASSACHUSETTS, ASSIGNOR T0 rnonson NATIONAL PRESS 00. me, A CORPORATION or DELAWARE.

SHEET-FEEDING MECHANISM.

Application filed November 16, 1927. Serial No. 233,843. I

This invention relates to improvements in sheet feeding mechanisms particularly designed for use with a cutting and creasmg press, though the invention 1s not expressly limited to such use.

More particularly the invention provides a feedin mechanism particularly well adapted for handling thick sheets of paper or cardboard for box making and similar purposes, and which paper is best out and creased on a platen type cutter and creaser as dlstinguished from a cylinder press for the same purpose.

The object of the invention 18 to provide a generally improved sheet feeding mechanism, wholly automatic 1n action and operation and adapted to be built in unit form ready to be attached to a platen cutting and creasing press and operated from the press.

My invention is embodied in an automatic sheet feeding mechanism in which the sheet is fed from the top of a pile, then carried well forward in over the platen and delivered as close as possible into final cutting posltion.

More particularly, one object of my lnvention is to provide a novel form of sheet separating mechanism for separating the top sheet fronithe pile and feed it to the grippers. Another object is to provide novel means for preventing more than one sheet from reaching' the grippers. Still another object of the invention and novel feature thereof resides in an improved sheet elevating mechan ism to place the top sheet at the proper level. Another object is to provide novel means for releasing the sheet from the grippers and quickly place it onthe platen.

With the foregoing and other objects in view, my invention is embodied in an automatic sheet feeding mechanism arranged and constructed as hereinafter set forth and as illustrated in the accompanying drawings in which 1 Fig. 1 is a side view of an automatic feeding mechanism embodying my invention showin the same connected to the press, with details omitted and parts broken away. In this view the press is shown in sheet receiving or open position.

Fig. 2 is an enlarged side view of the feeding mechanism with the parts in their respective positions immediately after a sheet has been fed into the grippers, with parts broken away and parts omitted.

Fig. 3 is a plan view of the feeder with parts omitted and broken away.

Fig. t is a detail View of the paper platform operating'mechanism partly in section and taken on the line 4% of Figure 3. i

Fig. 5 is a detail end view looking from the left in Figure 4 and with parts broken away. i I

Fig. 6 is an enlarged detail view ofthe sheet separating or push off -meehanism in posithe paper feed broken away.

Fig. 12 is a detail'front view of the paper retaining knife and guard.

Fig. 13 is a detail view showing the grippers in position at the moment the sheet is released and falls on the platen.

Referring to the drawings, the invention is disclosed, by way of illustrative example,

platen press. Machines of this type are used generally in the art ofmaking cardboard in connection with a cutting and creasing boxes and the like and do not require detailed description or illustration. The press is identified by its frame 1, oscillating platen 2 and stationary bed 3. The platen is operated by means of the usual connecting rods 4, one on each side.

The automatic feeder is assembledas aunit and adapted to beconnected with thepress in proper relation thereto and means are'eprovided for operating the feeder from the press. The feeder may be said to comprise, by way of sub-mechanisms, a paper supporting and A elevating mechanism; a paper separating and push off mechanism and a gripper mechanism for conveying the sheet to the platen, together with incidental relatedoperating parts and elements. The feeder, as a whole, is mounted. upon a suitable framework consisting of two side frames 5 and 6 connected by suitable cross members. i The frame rests upon columns 7 connected by bars Shaving rollers 9 by means'o'f which the feeder unit may conveniently be moved towards and away from the press on a track 10. Suitable 1 links 12 connect the feeder with the press,

there being one link on each side.

Figure 1 shows the left hand side of the machine, the front being towards the right, the rear to the left.

. The paper 13 is supported. on a platform 14 suspended by chains 15, 15. The chain on each side passes over a rear idler chain sheave 16, thence under idlers 17 and 17 Thence up over a chain drive sheave 18, thence down- 7 wardlyforming a loop 19, thence upwardly again over a second chain drive sheave 20 and thencedown to the platform. The'chain drive sheaves 18 and" 20 are best seen in Figure 4. They aremounted on a chain driving shaft 21 supported in upright side brackets 22, to the left, and'23 to the right. Figure 4 isa view looking towards the front of the machine. The chain drive shaft is operated stepwise by the following means.

- An operating shaft'24 is mounted in the brackets 22 and 23. Theishaft carries a ratchet 25, Fig. 2, driven by a pawl 26 mounted on ua pawl carrier 27 which oscillates freely on the shaft 24. An oscillating arm 28-engages the pawl carrier 27. A spring 29 serves to re turn the pawl carrier and pawl to initial starting position. When the arm 28 is oscillated, bymeans to be presently described,

the carrier and pawl are oscillated to drive the ratchet-and shaft 24' stepwise in a'clockwise direction as viewed in'Figure 2.,

At its other end, Fig. 4, the shaft 24 drives 1 a vertical worm shaft 30 by means of bevel gears 31 and 32. The worm shaft is suitably V mounted in the bracket 23 and carries a worm V33 which drives a' worm wheel 34 loosely mounted on the sheave drive shaft 21. A ratchet 35 is' keyed to the shaft 21 and is driven by two pawls 36, 36-mounted on the worm wheel 34. A spring 37keeps the pawls on the ratchet.

From this it will be seen, that the operating shaft 24'is driven stepwise at the one end 'jnearthe bracket 22, and in turn at its'other end drives the chain sheave drive shaft 21 by means of the bevel gears, worm and wormj ,wheel, and pawls 36 in engagement with ratchet 35,=the latter being fast on the shaft 21. The rotation of the latter of course drives the chain 15 to .raiseor lowerthe platform and paper. i

" It is, however, at times desirable to beable to raise or lower the platform quickly by rotating the shaft 21 by hand. Consequently it must be disconnected from its automatic driving-means. :At the left end this is accomplished by merely throwing back the pawl 26. At the other end the pawls 36 are lifted out of engagement'with the ratchet 35by rotatinga disk 38. The latter has two notches 39,

.39 to permit the pawls 36 to fall into engagemg SLlOkE.

ment with the ratchet. But when the disk is rotated the pawls are swung outwardly in an obvious manner and disengaged from the ratchet. The disk is provided with knobs 40 and inasmuch as it normally turns with the pawls there is always a knob handy for the operator to seize. Thereafter a suitable handle, not shown, may be applied either to the free end of the shaft 24 or the. free end of the shaft 21 to quickly operate the latter as will be understood;

During the operation of the machine a sheet will he removed from the pile for each operat It is, however, not-possible or practical to so regulate or proportion, the pile elevating mechanism to provide that for each stroke, the pile is lifted only to the extent of the thickness of a sheet. Means are therefore, provided for throwing out the chain driving mechanism when the pile of sheets reaches a certainpredetermined level. This is accomplished by a sheet height control mechanism. 9

Referring to Figure 2 it will be seen that the pawl carrier 2'? is provided with a notch 42 adapted 'to be engaged by-a stop pawl 43 pivoted on the bracket 22. The stop pawl is normally held out of engagement bythe control mechanisniwhich comprises a vertically adjustable linkj44 which engages the tail of the pawl. The lower end of the link is pivotedto a balancing arm 45 pivoted ona control shaft 46. On the other side of the shaft the arm 45 carries an adjustable counterweight 47. 7

The control shaft 46, Figs. 3 and 11, carries .in the middle an arm48-with a roller 49 which rests on top of the pile of sheets 13 under pressure of the weight 47. 50,50 are bearings for the shaft 46: The bearings are secured to cross bars 51, 51'which extend between the side frames 5 and 6.

So long as the top sheet is at the proper height, the roller 49 and counterweight 47 tend to rotate the control shaft 46 in an anticlockwise direction, see Fig. 11. Consequently the forward end of the balancing arm 45 with the link 44 remains elevated sufficiently to lift the tail of the stop pawl .43 and keep the later out of engagement with the pawl carrier 28.

' 'When, however, through the-platform raising mechanism the pile is elevated above the predetermined height, the roller '49 will be raised and cause the shaft 46 to be tipped in a clockwise direction against the force of the counterweight 47. Hence the link 44 will be When a few sheets have been removed, the roller 49 will drop, the counterweight will force the balancing arm and link 44 upwards to disengage the stop pawl from the carrier 27. The latter will be rotated anticlockwise, Fig. 2, by the spring 29 and the platform raising and sheet elevating mechanism will automatically resume operations. The foregoing describes the paper supporting and elevating mechanism and the automatic controlling means therefor.

I will now describe the sheet separating mechanism. See Figures 2, 3 and 6 to 10 inelusive.

The top sheet 52, Fig. 6, is separated from the pile 13 by being pushed frictionally rearwards away from the pile by a pushing roller 53 suitably mounted in a head 54 carried at the end of a rack bar 55. The head 54 also carries a brush roller 56 and a lifting roller 57. The pushing roller 53 is caused to engage the top sheet frictionally'under pres sure and move said sheet over the top of and away from the pile. At the end of this separating movement the push roller is elevated, and then moved forwardly in elevated position to initial position ready for the next sheet. To this end the following means are provided in duplicate, there being a push off mechanism adjacent each rearward corner of the sheet, see Fig. 3.

A base 58, Figs. 6 and 8, is screwed fast on the cross bars 51. The base has two forwardly extending arms 59, 59, the ends of which are supported on a push off shaft 60, which is supported in the two side brackets 22 and 23, Fig. 3. "The push off rack bar is reeiproeated between the arms 59 by means of a pinion, 61 fast on the shaft 60. The rack 62 of the bar is kept in engagement with the pinion by a roller 63, Fig. 2, below the bar and on which the bar slides.

The base 58 also has a rearwardly extending support 64., Figs. 6 and 8, which carries a fixed cam 65 and a movable cam 66 pivoted on 67. The movable'cam also supports a pressure roller 68. A spring 69 secured to the base support 64 extends in under the movable cam 66 and tends to depress the roller 68 to keep it in contactwith the top sheet. The movable cam piece carries a forward stop pawl 70. The fixed cam 65 carries another step pawl 71. Both of said pawls 7 O and 71 are adapted to engage a ratchet 7 2 secured to the roller 53. The base support 64 carries a lifting pawl 7 3 which rests by gravity on top of the fixed cam 65. The rack bar slides alongside the base support 64 and passes through a suitable guide 74. The base further carries a bell crank 75 which by means of a spring 76 causes a roller 77 to be pressed down upon the rack bar. The push off shaft 60 carries a gear 78 which meshes with a segmental gear 79 secured to the operating shaft 2a and is oscillated therewith.

The push ofi' shaft 60, Fig. 4, may be dis connected from the driving shaftQ l by withdrawing a pin 105 which connects the segmental gear 79 with the oscillating arm 28. The pin 105 has stops 106 adapted to be seated in grooves 107 in the arm when it is withdrawn. The pin is kept seated in the arm 28 fordriving connection by means of a spring 108.

The operation of the push off mechanism is as follows: Normally it is in the position shown in Figure 9 in which it will be seen that the push off roller 53, which has a roughened surface, is in frictional contact with the top sheet by gravity and under pressure of the spring 76. The roller is prevented from rotating because the pawl 7 O engages the ratchet 7 2. A further downward pressure is exerted on the sheet by the roller 68. On the feeding stroke of the machine, the roller 53 is pushed rearwards (to the left in Figure 9) by the pinion 61 engaging the rack 62. The parts are so proportioned that the roller carries the sheet with it into the position shown in Figure 6. However, at this time the lifting roller 57 has encountered the cams 65 and 66, rides up on said cams, passing under the lifting pawl 7 3 and runs on thehorizontal upper surface of cam 65. During this movement the ratchet 72 is engaged by the other pawl 71 and thus the push off roller is rotated a short distance and in contact with the brush 56 which serves to keep the push off roller free from fine particles of sheet material.

The neutral or return stroke follows iinmediately and the pusholf roller is now pulled During this forward, return, movement the push oif mechanism has been kept clear of the outgoing sheet. by gravity and falls back into position after the roller 57 passes'under it.

To repeat: The push elf roller or mechanism is given a lateral sheet separating and feeding movement sufficient to move the outgoing sheet away from the pile. The roller is then lifted and is elevated still further dur ing its return movement to give the sheettime to pass away from under. During this move.- ment the roller is rotated and cleaned, and at the beginning of the feeding stroke the roller is kept stationary so long as the pawl 70 engages the ratchet 72. The feeding movement is even, merging into the lifting and return movements in a smooth and easy manner. The movable cam 66, which would appear to have no function, is provided for the reason, that some times the sheet is at a slightly higher level. is lifted to correspond with the higher position of the push off rack bar and roller 53, it being remembered that the level of the base support 64 is fixed. a I

The separating movement of the sheet is The pawl 7 8 rests on the cam At such times themovable cam,

- tom of Fig. 3)'t-here is mounted a cross support 80 between the side frames, and centrally of said cross support there is affixed thereto a spacer 81. As the platform is elevated, being. guided along uprights 82, see Figs. 1, 2 and 6, the leading rear edge of the pile of sheets is moved up closely adj acentto the'inner surface of the spacer 81.

The cross support '80 carries gages one for each push off mechanism and located prefers ably in alinement therewith. Each gage consists of a base 83 which fits over the support SOand. is adjustable along the same by a suitable bolt 84. The base is'forme-d with an upright sheet side guide arm 85. To the latter is secured an. overhanging and downwardly extending fixedj aw 86. A movable jaw 87 is pivoted in the base at 88 and is ad ,justed withvrespec't to the fixed jaw by a gage screw 89. The base 83 is further provided with a vertical slot 90. The base is-rounded as at 91 and the movable jaw is formed with an upper rounded surface 92 so that the sheet may slide easily up over the base and movable jaw, in between the jaws and against a temporary stop member 93 which is operated vertically in the aforesaid slot 90, see Fig. 11.

' The vertical [stop 93 has a short up and down movementr within the gage base 83.

There is a stop in each gage and the two stops are operated by the following means, see bottom of Fig. 3 and Fig. 11. The two stop gages 93, 93 are mounted on a transverse shaft9t which moves vertically in slotted arm 97 to oscillate the same and to vertically.

guides 95, 95 secured to the cross support 80. 7 To, one end of the shaft there is pivoted a link 96, which is operated by a short arm 97 which turns freely on the main operating shaft 98 which is suitably mounted in the frame of the feeder.. Alongside the arm 97 there is a collar 99 secured to the shaft by a set screw- The'collar has two pins 100 and 101 which extend'in the path of the arm'97. The shaft 98 is oscillated to operate the, feeder and in alternate strokes the pins 100 and-101 hit the reciprocate the: cross shaft 9 1 to raise and lower the gages or stops 93. w The parts are. so proportioned and timed, that the stop 93,

has-a quick downward movement assisted by aspring 102' so as to disappearrwithin the gage base 83 just prior-to the moment when the grippers seize the sheet. The upward movementof the stops 93 is timed so that vent lateral movement'of those sheets.

the end of the upward movement of the link to provide a definitestop in an obvious manner. Y

ment of the topmost layers of sheets when the Means are provided for prexenting movetop sheet is being pushed off the pile. See

Figs. 3, 11 and 12. On the flat cross bars 51 there is secured athird bearing 110 forthe control shaft 46. This bearing is located centrally of the machine and is in addition to the two end bearings 50 aforesaid. The bearing 110 supports a forwardly extending knife shaft 111 on which thereis adjustably mounted a knife support'112 by means of a set screw 113. The knife support carries a sheet retarding knife 114 which is under pressure by a spring 115 and penetrates the pile of sheets to the extent of the first half dozen topmost sheets depending of course upon the thickness of the stock. The pressure of the knife may be regulated by a screw 116 above the spring 115 in an obvious manner. The knife support also carries a knife guard 117 pivoted at 118. lVhen the top sheet is pushed off the pile, the sheet is drawn against the knife which thus makes a very thin out in the margin of the sheet. At the same time, how? ever, the penetration of the knife'into' the sheets below the top sheet issufiicient to pre- In operation, of course the pressure of the knife will be regulated so as to not unduly retard the movement of the top sheet and hinder the operation of the-push ofi mechanism. The

knife guard is pivoted so that it will swing 'to one side and not obstruct the upward movement of the platform.

how the pile of sheets are elevated, how the top sheet is separated and placed in position to be'seized by the grippers and the several sub-mechanisms operate to' accomplish this result. It will further be clear from an inspection of Figure 3that the parts are adjustable transversely of the feeder .to suit the width of the sheet and the knife is adjustable'with respect to theforwa-rd edge of the sheets: Reference has been made to the upstanding arms 85' of the sheet measuring gages 83- In practice those gages will be adjusted as near the corners of'the sheets as 1 possible and the arm 85 will prevent transverse movement of the sheets. In Figure 3 the arms 85'are shown a short distance away from the sides of the sheet. It will further be understood that the sheet handling means described above absolutely prevent more than one sheet from passing through the gages, the movable aws 87 being adjusted to permit only one sheet to. pass, while the knife at the other edge prevents movement of the other sheets while the uppermost one is being pushed off the pile.

I will now describe the gripper mechanism by means of which the sheet is seized and conveyed onto the platen in the position shown in Figure 1. This mechanism includes a gripper carriage, upper and lower gripper jaws, means for guiding and operating the carriage and gripper openingand closing means.

Referring first to Figure 3 the gripper carriage comprises anupper gripper shaft 120 and a lower gripper shaft 121 which are joined by suitable braces 122. For the sake of clearness only two braces 122 are shown. There are usually more. The braces are connected by a transverse tie rod 123. The gripper carriage is, moved from the position shown in Figure 2, where the sheet is seized,

to the position shown in Figure 1, where the sheet is dropped on the platen 2. The gripper carriage operating means are as follows.

The feeder main operating shaft 98 ex-- tends across the machine and is supported in suitable bearings 125 at each side. At the extreme outer ends of the shaft there are affixed main operating levers 126, 126, the upper ends of which support the upper gripper shaft 120. The lower ends of levers 126 are connected by detachable links 127 to the connecting rods 4 ofthe press. As the latter operates, the levers 126 are oscillated to operate the gripper carriage as explained. There is thus imparted a swinging movement to the grippers, but in addition means are provided for moving the grippers outwardly parallel with the top plane of the pile of sheets and the parts are so arranged that the lateral movement of the grippers, precedes the downward swinging movement towards the platen. Of course the two movements merge into each other.

The lateral outward movement of the gripper carriage is accomplished by means of slides 128, one on each side, which move in swinging guides-129 pivoted at 130 to the side frames. Braces 131 similar to the braces 122 connect the upper gripper shaft 120 with the rearward ends 132 of'the slides. The tie rod 123 extendsto the braces 131. The'pivotal connection at 132 is coaxial with the lower gripper shaft.

. The guides 129 are swung on their pivots 130 by vertically movable arms 133 connected by a pin and slot connection at 134 to the guides. The arms 133 have rollers 135 operable by cams 136 on the main operating levers 126.

When the parts are in the position shown in Figure 2, the guides 129 lie horizontal and the slides 128 are moved forwardly, the gripper carriage being in its extreme forward position. When now the main levers126 swing towards the press, the slides 128 move mal position. p The grippers move forwardtoward the sheets in open position and are closed on the laterally in the guides 129 and the latter are.

swung ontheir pivots 130 into the position shown in Figure 1, thisswinging movement being accomplished by the vertically movable The movement then continues arms 133. until the gripper carriage reachesitsextreme rearward position in Figure 1. The arms 133 have slotsl37 which guide the arms on the main shaft 98. The construction is on both sides ofthe press.

Referring now to F iguresfi, 7 and 8, agripper bar 140 extends between the gripper shaft-s. 'AhltS lower end the, gripper bar forms afixed gripper jaw 141 (see also F lg.

13) and carries asheet stop 142. On the lower. gripper shaft 121 and adjacent tothe gripper bar there is clamped to the shaft a lower gripper jaw 143 which is ofiset and extends in under the fixed jaw 141. The grippers close to seizethe sheet as shown in Figure 6. They are opened to drop the sheet as shown in Figure 13. In'order that the sheet maybe definitely released from the gripper and drop alike on the platen the gripper bar 140 carries a sheet beater144pivotcd at 145 and operated by a link 146 froma shortarm 147 fast on the-uppergripper shaft 120.

On the cross support80and inalinement There are two sets of grippers as shown in Figure 3. With reference to this figure it should also be noted that on the right hand half of the drawing, the top sheet 52is shown in separated pushed off position in the grip of the grippers. The left half of this view shows the sheets 13 in their norsheet. as in Fig. G-by the following means,

see Fig.11. To'the loweri gripper shaft is secured an arm 153 connected by a pivoted link 154 with another arm155 whichis loosely mountedon the upper gripper shaft 120. The arm 155 has a pin'156.- A spring 157 extends from'the arm 153 to the link 15.4. a On the bars 51thereis mounted an abutment 158 which carries an adjustable gripper closing stud 159. As the gripper carriage (is movedtoward the front and passes in over the feeder, itcomes toa stop at the endof its movement when the upper gripper shaft moves against the abutment- 158 and as 159. The arm 155 isv swung clockwise up,-

' wardly, the" pin 156 hits .theend of the link 15 1, pushes the link leftwardly on the drawing', giving to the arm 153 and lower gripper'shaft'121 an anticlockwise movement to close the gripper jaw 143 up against thefixed jaw 141 and the grippers seize the, sheet. The grippers are then held closed by the spring 157 The sheet stops 142 insures perfect alinement of the leading edge of the sheet when it is seized. f

The grippers are opened as in Figure 1 by the'following mechanism. A gripper opening cam 160 is adjust-ably mounted on the side frame 5. To the upper gripper shaft 120 there iszaflixed an arm'161 connected by an adjustable link 162 to another arm 163 pivoted at 165; on the main-operating lever 126. The arm 163 carries'a roller 164; which ,engagesthe cam underinfluence of a spring At the end of the outward movement-the roller 165 runs over the cam- 160 and through the connectionsdescribed imparts an anticlockwise sudden movement to the upper "gripper shaft 120. ,On th'e latterand adja cent to thefaforesaid-closing arm 155' there is mounted an adjustable opening abutment 168; Consequently when'the shaft 120 is rocked anticlockwise, the abutment 168 descends upon-the link 154. moving itand the arm 155 downwardly anticlockwise and through the link 154 and arm 158 theslower gripper-shaft is rotated clockwise to open the grippers. Simultaneously therewith the sheetrbeater 1414 is moved downward and definitely knocks the sheet awayjfrom the grippers and onto the platen where it slides into cutting position against the usual stop gages 170 as the platen moves down into closed position. 7

The ratchet operating arm 28 hasa depending lever 171 which, is connected by a [link 172 to the main lever 126 for operating the platform raising mechanism. V In operatiom'the platen 2 oscillates con- 7 tinuously, thereby moving the levers 126-in Z a. similar fashion.

I The sheet separating means'operates' to position a sheet for the gripper mechanism during the closing movementof the platen and during the same movement'ofv the platen the'gripper mechanism returns toward the sheets with jaws in open position. As'the gripper mechanism nears the end of its stroke, the uppermost sheet of the stack, is pushed out 'by the sheetseparating mechanism into'the position shown inFig. 6. The'grippers approach the sheet and jaws 1 13 are closed thereupon by reason ofthe abutment of stud-159 with the; arm 155. This action occursas the platen 2 moves into, engagement with bed 3. Asthe platen moves away from-its bed, the levers=126 push the grippers toward the platen, and the leadmg; ends. of such levers, being connected to the slides 128 travel at first in a straight line parallel with the top face of the stack ofi tions more nearly parallel with the sheet receiving face of platen, when it is fully open and in sheet receiving position. This causes the grippers to dipdownwardlyand travel in a curved path until they finally approach very'closelyto the lowest edgeof the platen. At such time, the grippers are opened to release the. sheet, which has to drop only a very short distance and can therefore, be positioned properly on the platen against stops 170. 7

Automatic sheet feeders constructed as herein disclosed are in actual operationin the industry and handle successfully all kinds of cardboard and stock for box making purposes. 1

I claim-{ I 1. Paper separating means comprising a support, a separating member mounted there on, a paper separating; roller revolubly secured to said member, means for operating thelatter in one direction with the roller in frictional contact with the sheet to be sepation of the roller at the beginning of its first,

said movement, a rotatable brush in said separation mechanism and ,means' causing the roller to'be rotated, in contact with said rotatable brush at the end of its first'said movement.-

2. A paper vseparating mechanism comprising a support, a bar mounted to slide thereon, a head on said bar, means on said head adapted to frictionally engage the sheet to be separated, means engaging the bar for operating said head to separate the sheet by a lateral movement thereof and a fixed and a movable cam on said support,-either of which is adapted to lift the head away fromithe sheet after thelatter has been separated. 1

3. In an automatic feeder,-the combination of means for separating the top sheet from the pile by a lateral sliding movement,imeans for preventing a similar lateral movement of sheets below the top sheetcomprising supporting means, a knife adjustably carried thereby, a spring for causing said knife to penetrate the top layers of the sheets at the margins thereof and a knife guard pivoted on said supporting means.

4. Means for separating a sheet from a pile ofgsheets comprising in combination a fixed gage, means for separating the top sheet and moving it into and through said gage, a movable stop forpositioning the sheet in said gage and grippingmeans for seizing and conveylie ing the separated sheet away from the pile after it has passed through the gage.

5. In a paper feeding device the combination of a pair of grippers for seizing and conveying the paper, opening and closing means for said grippers and means movable with the grippers for forcibly and suddenly delivering a blow to the paper to release it from the grippers.

6. In a paper feeding device the combination of a relatively fixed gripper bar forming an upper gripper jaw, a lower gripper jaw pivoted on said bar to cooperate with the upper gripper jaw to seize and convey the sheet, means for opening and closing the gripper, a sheet beating member pivoted on said gripper bar for forcibly releasing the sheet from the grippers when they open and means for operating said gripper and sheet beating member.

7. A paper feeding device for a press comprising means for supporting the stock, a gage located adjacent the leading edge of the stock, said gage eomprisinga base having an upright supporting member, an upper overhanging fixed gage jaw on the latter, a lower gage jaw pivoted in the base inalinement with the upper jaw, means for adjusting the space between the said two jaws to permit only one sheet to pass therebetween, said base and lower jaw having upwardly stopping rounded surfaces to facilitate the removal of the paper, said base having a slot, a sheet stop member in said slot, means for separating the top sheet and move it laterally between said jaws and means for operating said stop member to project the same into the path of the sheet to limit the movement thereof.

8. The combination with a press, of a paper feeding device therefor comprising in combination a framework, a stock carrying platform having operating mechanism compensating for the removal of sheets, controlling means for the operating mechanism of said platform toinsure the positioning of the top sheet at a predetermined level, gaging and sheet stopping means located adjacent the leading edge of the sheets,

means operable from said operating mech v 9. A gripping mechanism of the character,

described comprising an upper and a lower gripper shaft, a gripper bar extending therebetween and forming a fixed gripper jaw, a movable gripper jaw secured to the lower gripper shaft, a link connection extending between said shafts for operating the lower gripper shaft to close'the grippers, fixed means for actuating said link connection to close the grippers, a movable cam and means operable thereby for operating the said lower shaft to open the grippers.

10. In combination, a sheet gage member comprising a base forming an upright side member, an overhanging fixed jaw secured thereto, a lower jaw pivoted on the base in alinement with the upper jaw, means for adjusting said lower jaw to permit the passage of but a single sheet between the jaws and astop member operable vertically in said base to momentarily arrest the passage of a sheet, between the said jaws.

CARL r. FRAUENBERGER.

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