US3100110A - Apparatus for removing blanks or sheets from the top of a supply stack - Google Patents

Description

Aug. 6, 1963 R. WINKLER ETAL 3,100,110 APPARATUS FOR REMOVING BLANKS OR SHEETS FROM THE TOP OF' A SUPPLY STACK 2 Sheets-Sheet 1 Filed NOV. 2l, 1961 Aug 6, 1963 R. WINKLER ETAL 3,100,110

APPARATUS PoR PEMovTNG BLANES 0R SHEETS PROM TEE ToP oP A SUPPLY sTAcx Filed NOV. 2l, 1961 2 Sheets-Sheet 2 IN V EN TOR.

3 ,190,1 l0 Patented Aug. 6, 1 963 3,196,110 APPARATUS FR REMOVHNG BLANKS R SHEETS FRM THE TOP 0F A SUPPLY STACK Richard Winkler, Rengsdorf, near Neuwied, Rhineland,

and Kurt Dnnehier, Wollendorf, near Neuwied, Rhineland, Germany, assigner-s to Berkley Machine Company,

Kansas City, Mo., a corperation of Missouri Filed Nov. 21, 1961, Ser. No. 153,864

Claims priority, application Germany Feb. 1, 1961 9 Claims. (Ci. 271-28) This invention relates to apparatus for removing blanks or sheets from the top of a supply stack and starting feed of the blanks or sheets onto the top of a shallow working stack from which the blanks or sheets are removed from the bottom thereof into a rotary machine for making envelopes, dat bags, or the like, ythe present invention being an improvement in a corresponding apparatus disclosed in copending application Serial No. 774,677, led in the United States Patent Oiice on November 18, 195'8 and now Patent No. 3,020,043, issued February 6, 1962.

-In the apparatus of said application, the supply stack is lifted automatically with removal of blanks or sheets from the stack, in order to maintain a substantially constant position for the upper surface of the supply stack With reference to the blank or sheet removal mechanism. The Iblank or sheet removal mechanism includes a suction nozzle that swings into contact with the topmost blank or sheet and lifts it into position to be removed by rotary means. For this purpose a sensing lever is used to bear upon the stack for switching on the stack lifting mechanism at a predetermined reduction in the height of the stack, and to stop the lifting mechanism after the intended height has been attained.

It has been found in practice of the invention covered by said application that the blanks or sheets in the supply stack are often uneven or buckled and bent at the margin, which causes difficulty and disturbance in the operation of the sensing lever and also in the removal of such blanks or sheets from the stack.

-It is, therefore, an object of the invention to provide an improved control of the stack elevating means that reliably operates on the blanks or sheets of the supply stack, and to provide lingers to hold down marginal face portions of the blanks or sheets which operate alternately with a hold-down tongue, both working in synchronism with the suction means, so that when the lingers lift to release the uppermost blank or sheet after it is engaged and initially lifted by the suction nozzle, the tongue enters below the partially lifted blank or sheet to hold down the marginal face portion of the next lower blank or sheet while the uppermost blank or sheet is being removed from the stack.

It is also an object of the invention to provide control of the supply stack elevating mechanism, that is initiated by the hold-down ngers to maintain the top level of the supply stack in a substantially constant range relatively to the blank removal mechanism. The fingers, therefore, have the dual -function of holding down the marginai face portions of the blanks, and, following the reduction in height of the stack, to set the elevating mechanism in motion for maintaining the -top level of the stack Within the Working range of the blank removal mechanism.

In accomplishing these and other objects of the invention, improved structure has been provided, the preferred form of which is illustrated in the accompanying dra ings, wherein:

FIG. l is a vertical section through a mechanism for successively removing blanks from the top of a working stack supported on an elevating mechanism and employing the features of the present invention, the section being taken on the line 1 1 of FIG. 3.

FIG. 2 is a vertical section through the mechanism illustrated in FIG. l, but taken on 4the line 2-2 of PIG. 3 to better illustrate the control mechanism for operating the stack elevating means.

FIG. 3 is a plan view of the mechanism illustrated in FIGS. 1 and 2.

FIG. 4 is a horizontal section on the line 4--4 of FIG. 1.

FIG. 5 is a perspective view of the hold-down tongue.

FIG. 6 is a perspective view of one of the hold-down ngers.

FIG. 7 is a diagrammatic view of one type of stack elevating mechanism that may be used for maintaining the level of the supply stack relative to the` blank removing mechanism.

While the mechanism of the presen-t invention is adapted to work on either blanks or sheets, the description will refer to blanks from which envelopes are formed in an envelope making machine.

Referring more in detail to the drawings:

1 designates a supply stack of envelope or similar blanks that are to be removed from the top of the stack by a blank removing mechanism, generally indicated i2, for delivery to a rotary envelope making machine as disclosed in the above mentioned copending application, the present invention pertaining only to the blank removal mechanism that removes blanks from the supply stack, and the control of the stack lifting mechanism, generally indicated 3 and illustrated diagrammatically in FIG. 7 and by which the top level of the stack is kept in the desired working range of the blank removal mechanism 2.

The stack lifting mechanism 3 includes a platform 4 that may be lifted by chains 5 and 6 connected to the platform and operating over sprockets 7 and 8. One of the sprockets is actuated by a ratchet wheel 9 and is advanced step by step through a pawl 10 oscillatable over the teeth of the ratchet wheel by a rock lever 11, which is actuated by a driving gear 12 whenever the pawl is moved into engagement with the teeth of the ratchet Wheel by an electromagnet 13.

While a specific lifting mechanism has been briefly described, it is to be understood that other lifting mechanisms may be employed that have an actuator and means for setting the actuator in motion to lift the stack and to suspend the lifting operation when the stack has been lifted a desired amount to keep the blanks in supply to the removal mechanism 2.

The blank removal mechanism 2 includes a horizontal shaft 14 that is carried above the stack 1 and is driven from a rotary part of the envelope making machine, not shown. Mounted on the shaft 14 are withdrawal segments 15-15 having a predetermined mutual spacing on the shaft in accordance with the width of the blanks, and which are xed to the shaft in any suitable manner to permit adjustment in the spacing thereof. The withdrawal segments 15 have cylindrical faces 16 terminating in arcuate cutouts or recesses 17 extending inwardly from the peripheries of the withdrawal segments 15, as is illustrated in FIGS. 1 and 2. The segments 15 are driven in the direction of the arrow 18, and the forward edges `19 (FIG. 1) formed by the recesses 17 are inset from the cylindrical faces 16 to provide a shoulder 20 spaced rearwardly from the edge 19. The segments 15 15 may also have controlled Vacuum ports located in the periphery thereof just behind the shoulders 20, as indicated at 2G (FIG. 2).

Cooperating with the withdrawal segments y---15 are correspondingly spaced apart rollers 21 21 of resilient material and which are adjustably mounted on a shaft 22. rThe rollers 21-21 are supported above the supply stack 1 with the peripheral faces 23 thereof in position to make contact with the cylindrical faces 16 of the withdrawal segments -15 and to rotate in the direction Of the arrow 24. Located below each of the rollers 21-2'1' and at a small spacing from the upper surface of the supply stack are guide plates 25, each having curved portions 26 extending upwardly of the faces of the rollers 21-21'. Provided in the curved portions 26of the guide plates are suction openings 27, which are connected by exible ducts 28 to a suction line (not shown) wherein a suction ismaintained at intermittent periods in rhythm with the revolution of the withdrawal segments 15-15.

A suction feeding device 29 is carried between the withdrawal segments on an oscillatory shaft 30 that is oscillated in rhythm with the envelope making machine. The suction feeding device includes a tubular arm 31 that is secured at one end to the oscillatory shaft 36 by a clamping holder 32, to retain the tubular arm in conriection with a suction port 33 from a longitudinal bore 34 in the oscillatory shaft 30, and in which a suction is intermittently established in working rhythm with the suction" device 29. The free end of the tubular arm 31 carries a relatively broad suction nozzle 35 having a downwardly opening suction port 36 to make contact with a margin A of the uppermost blank B in the supply stackV `1.

rIhe suction device is oscillated to raise and lower the nozzle 35, once per revolution of the withdrawal segments 15-15, from a lower position 37 to an upper position 38 (FIG. 1). When the recesses .17 of the Withdrawal segments 15-15 begin to move over the stack, the nozzle 35 of the suction device swings to its lower position 37 (dotted lines FIG. l) and a suction is established through the nozzle 3S to lift the margin A of the topmost blank B from the stack 1 and to carry the seized portion of the blank into the recesses 17 of the withdrawal segments `15---15 to be engaged by the edges11'9, which then carry the blank into contact with the peripheral faces 23 of the rollers 21-21'.

During movement of the blank between the rollers 21;21' and the cylindrical faces 16 of the withdrawal segments 15-15', the suction through the openings 27 assures that the blank B is in Contact with the curved ends 26 of the guide plates 25, thereby cooperating with the edges 19 of the withdrawal segments for keeping the nozzle working space open for return movement of the nozzle 35 toward the stack for engagement with the following blank C (FIG. 2).

As above pointed out, it is found that the marginal portions A of the blanks to be contacted by the nozzle 35,' are not ilat, but are often uneven, with the edges buckled or bent at the margins of the blanks. Therefore, to hold such portions of the blanks fiat, the present invention provides means at the respective sides of the path of the nozzle 35 for engaging the uppermost blank prior to Contact of the nozzle 3S therewith.

In the illustratedv instance, this means includes a rock shaft 39 located at the side of the stack 1 below the shaft 14, and fixed` to the shaft 39 are spaced apart collars 40:--40 carrying radially projecting arms 41 terminating in angularly directed lingers 42. Also fixed on the shaft 319 is a crank arm 43 that is connected by a pin 44 with a reciprocating rod 4S. The rod 45 has a yoke portiony 4 6 havingspaced apart arm portions 47 and 48 for slidingly engaging opposite sides of the shaft 1'4 and whereon the rod 45 is adapted to rock and slide when oscillating the fingers 42 into and out of contact withv the uppermost blank A in the stack 1, the respective positions being indicated by the numerals 49 and 50 (FIG. 1).

y In order to actuate the rod to oscillate the arms 42, the shaft `1,4 carries a cam 51 that is fixed to the shaft 14- and has a high lobe portion 52 and a diametrically opposite low lobe portion 53. Rotatably mounted on l the rod 45 is a cam follower in the form of a roller S4 that is held in contact with the surface of the cam 51 by a spring 55.

The mechanism is so timed that just prior to descent of the nozzle 35 to the position 37, the cam follower 54 has moved from .the high lobe portion 52 of the cam and is traveling toward the low lobe por-tion 53, so that the spring 5S rocks the shaft 39 in a clockwise direction (FIG. il), to bring the 'ngers 42 into holding contact with the margin A of the next blank to be engaged by the suction nozzle 35. After engagement of the suction nozzle 35, the high lobe portion 52 is contacting the follower 54 to cam the rod 45- downwardly to swing the rock shaft 39 in an anticlockwise direction (FIG. l) to effect lifting of the fingers l42 to the full line position indicated at 49, fto thereby clear the edge of the blank when the nozzle 35 carries the margin of the blank B upwardly into a position where it is engaged by the edges 19 of the withdrawal segments `15--15'.

In order to hold the margin of the succeeding blank C in flat condition when the fingers -42 are lifted, and .to provide a stop for the top of the stack 1, a supplemental stop isprovided inthe form of la tongue 56. The tongue 56 extends laterallyl from an arm 57 that is adjfustahly carried on la holder 5S. The bolder 5S is fixed to a rock shaft S9 located below the -rock shaft 39, and which is oscillated in timed relation therewith so that when the fingers 42 tare out of position, the tongue 56 is in position to engage the stack, and when the tongue 56 is swung out of position, the `fingers 42 are in position to hold down the marginal face portion of the topmost blank.

It is pointed out that the highest point of the fingers 42 is determined by the lift aiorded by the high lobe portion 52 of the cam, while the lowest position of the yfingers 42 is 'determined by their contact with the top surface of the supply stack at the margin thereof, and only a very low level of the top lsurface of the supply stack, that is below the nozzle position 37, will bring the `cam follower into contact with the -low lobe portion 53 of the cam 51. When enough blanks have been rernoved from lthe stack for the fingers 42 to drop below the position 5b shown by the dotted lines in FIG. l,l the stack 1 will be lifted automatically, and the elevating mechanism must be stopped when the top Asurface of Athe stack has been returned to the required or normal height. This is accomplished through the fall of the fingers 42 below their dotted `line position `50. To accomplish this result, the rod 45 has :an upward extension 59 carrying a roller 60 that is adapted .to engage and close a switch 61 (FIG. 7) when the cam follower is engaging the low lobe portion 53 lof the cam 51. The switch 61 is connected into the electric circuit 62 which supplies an enery gizing current to the electromagnet 13 (FIG. 7) for effecting lift of the stack 1. Energization of the electromagnet will bring the oscillating pawl 10 into engagement with a tooth of the ratchet wheel 9, so that movement of the ratchet wheel in `an anticloekwise direction will rotate the ratchet wheel 9 and sprocket 8 to lift the stack 1 to la 4position where fthe uppermost blank contacts the stop tongue 56. As the stack is lifted and the iingers 42 move upwardly, the high lobe portion 52 of the cam 51 is in position to move the rod 45 downwardly to carry the roller eti away from the switch 611 Ito allow the switch 61 Ito open and break the circuit to the electromagnet 13. Interruption of the circuit will permit the pawl 10 to be lifted by 'a spring or the like from the teeth of the ratchet wheel 9 and stop upward movement of the stack. The travel of the ratchet pawl 10 should be adjustable to cornpensate for various paper Vthicknesses, as for thicker papers the elevator Will need to travel upward `a bit faster :than for thinner papers.

In using the mechanism of the character described, the platform 4 is moved to a low position. The blanks or sheets, as the case may tbe, are piled on the platform 4 in la vertical stack ll in sufiicient number to supply the envelope making machine for a substantial time. The withdrawal segments S-ll and resilient rollers Zit-2l', together with the guides 25, are adjusted according to the width of the blanks. The tongue 56 is adjusted on the holder 58 to the desired height relatively to the fingers Wit-h the envelope making machine in operation and the shafts ld and 22 rotating in timed relation with the machine and Iwith the rock shafts 3h, 39 and S9 oscillating in timed rhythm, the removal of the blanks from the stack is as follows:

Starting with the lingers 42 holding down the marginal edge A of the topmost blank B, the nozzle 35 moves toward the margin A of the topmost blank B and lthe suction through the port 36 of the nozzle 3S becomes effective to seize the blank at the margin A thereof, which lifts lthe margin A sufficiently for the tongue 56 to engage the next blank C for holding down -tlie m-arginal face portion thereof while the seized blank B is removed. Upon engagement of the tongue 56, the lingers 4Z are lifted free of the seized blank l The nozzle 35 is now lifted to the full line position 3S (FIGS. l and 2), to carry the marginal portion A of the blank B into the recesses 17 of the Withdrawal segments -15' and in position to be engaged by the edges i9 of the withdrawal seUments 15-15, whereupon the edges 19 push the blank B into contact with the rollers 2li-21 `while it is being seized to the curved portions 26 of the guides by the suction then established through the ports 27. Continued rotation of the withdrawal segments 5-l bring the blank into the space between the faces 23 of `the rollers 2-2l and the withdrawal segments provided by the shoulders 2t?. The vacuum nozzle has released the blank as soon as it is lifted into the recesses of the segments 15-15. As soon as the shoulders 210 of the withdrawal segments reach the faces 23 of the rollers Zl-Il, the suction in the ports 27 is shut off and the suction through the ports 2li is made effective to withdraw the blank B from olf the stack and start the blank B on its way to the feed stack of the envelope making machine.

Upon release of the blank B by the suction nozzle 3S, the fingers 42 swing back into engagement with the stack, the tongue 56 swings out of engagement with the stack, and the nozzle 35 swings downwardly to begin removal of the succeeding blank C in like manner.

The fingers 42 are lifted in response to the high lobe portion 52 of the cam 5l and are brought into contact with the stack by the spring 55 when the high lobe 52 rides off of the follower roller 54.

lf the support of the fingers 42 by the stack is such that the lingers do not drop below their dotted line position 59 in FIG. l, there is no adjustment of the stack. But after enough blanks have been removed for the fingers to drop below the dotted line position Sil, the roller 60 on the extension 59 of the rod 45 makes contact with the switch 6i to close the circuit 62 for energizing the electromagnet 13, which moves the oscillating pawl liti into driving engagement with the sprocket 9. This results in lifting the stack l until the lingers are lifted by the stack above their dotted line position, whereupon the roller ed is carried out of contact with the switch 6i. The switch 6l now opens for interruption of current how in the circuit 62 to the electromagnet r3.3, which allows the pawl itl' to be lifted from the teeth of the ratchet wheel 9, stopping lift of the stack until enough blanks have been removed to again start the stack elevating means in motion.

lt may be desirable to build up enough blanks in the feed stack to supply the envelope making machine while the elevator of the supply stack after reaching its upper position may be stopped and run back to its lower position 4for placing a new supply stack thereon, after which the mechanism of the supply stack is again placed in operation to continue feed of the blanks to the feed stack before the feed stack has been exhausted. With this method -of operation, the envelope making machine will be in continuous operation While the supply stack l is replenished. The exact ratio of the feed from the feed stack and feed to the feed stack Would actually be determined by the weight of the paper used. The supply stack feeder mechanism might be required to Work anywhere from possibly ten percent faster than the rate at which the envelopes are actually produced. This might involve storing an adequate supply somewhere -in the system, but it will have no bearing upon the mechanism of the present invention except that the feed of the supply stack may be varied to meet the conditions.

While the invention is described particularly to supply blanks to the feed of an envelope making machine, it is obvious that the invention is adaptable to feed of various sheets to any type of sheet processing machine.

From the foregoing it is obvious that the present invention provides means for holding the marginal face portions of the blanks in hat condition for the orderly withdrawal of the blanks, and that the means for holding down the blanks is also utilized for controlling lift of the stack, whereby the top level of the stack is kept automatically within a range from which the blanks are removed by the withdrawal mechanism 2.

What is claimed and desired to be secured by Letters Patent is:

l. `in combination with means for removing blanks from the top of a supply stack, elevating means for supporting the supply stack, a first means for holding down a marginal face portion of a topmost blank in the stack, means supporting said holding means for movement out of and into holding contact with the marginal face portion of the topmost blank in the stack, a second holding means, means for supporting the second holding means for movement into and out of holding contact with the marginal face portion of the succeeding blank, means for alternately actuating the respective holding lmeans so that one is bearing upon the marginal face portion of a blank when the other is out of holding position, means for actuating the elevating means, and means responsive to said rst holding means for effecting operation of the elevating means after removal of a Ifevv of the blanks to maintain the blanks in the stack in position to be removed by said blank removing means.

2. In combination with withdrawal segments and rollers cooperating with the Withdrawal segments for removing blanks from the top of a supply stack, means for supporting the supply stack, means for holding down a marginal face portion of the topmost blank in the stack, means for moving said holding means into and out of holding contact -with the marginal face portion of the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for movement into a posiion for seizing the topmost blank and to carry the seized blank into contact with the withdrawal segments for removal from the stack, a second holding means for holdmarginal face portion of the succeeding for supporting the second holding means for movement under the topmost blank `when lifted by the suction nozzle to engage the marginal face portion of said succeeding blank in the stack, and means for alternately actuating the respective holding means so that one is bearing upon the marginal face portion of a blank when the other is out of holding position.

3. ln combination with withdrawal segments and rollers cooperating with the withdrawal segments for removing blanks from the top of .a `supply stack, elevating means for supporting the supply stack, a first means for holding down a marginal face portion of the topmost blank in the stack, means for moving said holding means into and out of holding cont-act with the marginal face portion of the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for movement into a position for seizing arcano the topmost blank xand to carry the seized blank into ecntact with the withdrawal segments for removal from the stack, o second holding means, means for supporting the second holding me ans for movement under the blank lifted by the suction nozzle `and into engagement with the marginal face portion next blank in the stack, means for 'alternately actuating the respective holding means so that one is bearing upon the marginal edge portion of -a blank when the other is out of holding position, means for actuating the elevating means, `and means responsive to one of said holding means vfor electing :operation of the Iactuating means yof said elevating means -afterremoval of la few ofthe blanks by said blank removing means to maintain the blanks in the stack in position to be seized by the nozzle.

4. An apparatus including rotatable withdrawal segments each having a recess in the periphery thereof to provide an entering edge, rollers cooperating with the withdrawal segments for removing blanks from the top of a supply stack, elevating means for supporting the supply stack, lingers for holding down a margin-al face portion of the topmost blank in the stack, means for oscillating said lingers into and out of holding contact with the topmost blank in the stack, a suction nozzle, means lor supporting the suction nozzle for movement into ya position for seizing the top-most blank and to a position for carryingy the seized blank into the recesses for entrance of the entering edges of the withdrawal segments under the topmost blank to carry said blank into contact with said rollers, a cam rotatable with the withdrawal segments, .a reciprocatory bar, ya cam :follower on said bar, -means connecting the bar with the lingers to lift the lin-gers out of contact with the toprnost blank to release said blank when seized by the suction nozzle, :and resilient means connected with said bar for returning the lingers into holding contact with the next lower blank after passing ot the seized blank between the peripheries of the segments 4and said rollers.

5. An apparatus including rotatable withdrawal segments each having a recess in the periphery thereof to provide lan entering edge, roller-s cooperating with the peripheries of the withdrawal segments yfor removing blanks `from the top of -a supply stack, elevating means for supporting the supply stack, lingers for holding down -a marginal lace portion of the topmost blank in the stack, means for oscillating said lin-gers -into and out of hold-ing contact with the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for movement into a position for seizing the topmost blank and to a position for carrying the seized blank `into the recesses of the withdrawal segments for entrance of said entering edges between the stack and said blank to bring the blank between the peripheries of the segments and said rollers for removal lfrom the stack, la cam rotatable with the withdrawal segments, ya. reoiprocatory bar, a cam follower on said bar, means connecting the bar with the lingers to lift the lingers out of IContact with the toprnost blank to release said blank when seized by the suction nozzle, resilient means connected with said bar and for returning the lin-gers -into holding contact with the next lower blank after passing of the seized blank, la tongue, means supporting the tong-ue lor movement under the seized blank to hold down the marginal face of the next blank during lift of the 'ngers, and means for actuating the tongue galternately with the fingers.

6. An apparatus including rotatable withdrawal segments each havinga recess Ain the periphery thereof to provide an entering edge, rollers cooperating with the peripheries of the withdrawal segments vfor removing blanks from the top of a supply stack, elevating means for supporting the supply stack, lingers for holding down a margin-al lace portion of the topmost blank in the stack, means for oscillating said fingers into and out of holding contact with the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for move-V ment into a position for seizing the topmost blank and to a position for carrying the seized blank into recesses of the withdrawal segments for entrance of said entering edges between the stack and said blank to bring said blank between the peripheries of the segments and said rollers for removal from the stack, a cam rotatable with the withdrawal segments, fa reciprocatory bar, a cam follower on said bar, means connecting the bar with the ngers to lift the lingers out of contact with the topmost blank to release said blank when seized by the suction nozzle, resilient means :connected with said bar -for returning the ngers into holding contact with the marginal face of the succeeding blank :after lifting of the seized blank by the suction nozzle, means for actuating the elevating means, and means responsive to the extent of movement of the bar by said resilient means for ettecting oper-ation of the actuating means lor said elevating means after removal of a few of the blanks to maint-ain the top blank in the stack in position to be seized bythe suction nozzle.

7. An apparatus including rotatable withdrawal segments each `having a recess in the periphery thereof to provide an entering edge, rollers cooperating with the peripheries of the withdrawal segments for removing blanks from the top of a supply stack, elevating means for supporting the supply stack, fingers lor holding down a marginal face portion of the toprnost blank in the stack, means for oscillating said lingers into and out of holding contact with the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for movement into a position for seizing the topmost blank and to a position for carrying the seized blank into the recesses of the withdrawal segments for entrance of said entering edges between the stack and the seized blank to bring said blank between the peripheries of the removal segments and said rollers for removal from the stack, a cam rotatable .with the withdrawal segments, a reciprocatory bar, a cam follower on said bar, means connecting the bar with the lingers to lift the lingers out of .contact with the topmost blank to release said blank when seized by the suction nozzle, resilient means connected with said bar tor returning the lingers into holding contact with the marginal face portion of a succeeding blank after lifting the Seized blank by the suction nozzle, a tongue, means supporting the tongue for movement under the seized blank to hold down the marginal face of the next blank during lift of the lingers, means for actuating the tongue 4alternately with the lingers, means for actuating the elevating means, and means responsive to the `extent of movement of the bar by said resilient means for ellecting operation of the actuating means for said elevating means after removal of a few of the blanks to maintain the top blank in the stack in position to be seized by the suction nozzle.

8. In an apparatus of the character described, withdrawal segments, rollers cooperating with the withdrawal Segments for removing blanks from the top of a supply stack, means for holding down -a marginal face portion of the topmost blank in the stack, means for moving said holding means into and out of holding contact with the topmost blank in the stack, a suction nozzle, means for supporting the suction nozzle for movement into a position for `seizing the :topmost blank to carry the seized blank into contact with the withdrawal segments for removal from the stack, and guides under the rollers and having curved portions extending upwardly of the rollers and having suction ports for sucking the blank into contact with the curved portions of the guides while the suction nozzle is carrying the blank into position to be engaged by the withdrawal segments.

9. In an apparatus of the character described, withdrawal segments, rollers cooperating with the withdrawal segments for removing blanks from the top of a supply stack, elevating means for supporting the supply stack, means for holding down a marginal -face portion of the topmost blank in the stack, means for moving said holding means into and out of holding contact with the topmost blank in the stack, -a suction nozzle, means for supporting the suction nozzle for movement into a position for seizing the topmost blank and to a position for carrying the seized blank into contact with the withdrawal segments for removal from the stack, `a second holding means, means for supporting the second holding means for movement under the blank lifted by the suction nozzle and into engagement with the next blank in the stack, means for alternately actuating the respective holding means so that one is bearing upon the marginal face portion of a blank when the other is out of holding position, and guides under the rollers and having curved portions extending upwardly of the rollers and having suction ports for sucking the blank into contact with the curved portions of the guides while the suction nozzle is `carrying the seized blank into position to be engaged by the Withdrawal segments.

References Cited in the le of this patent UNITED STATES PATENTS 854,222 Knapp May 21, 1907 1,420,458 Steinmetz June 20, 1922 2,942,877 FoWlie et al. June 28, 1960

Claims (1)

1. IN COMBINATION WITH MEANS FOR REMOVING BLANKS FROM THE TOP OF A SUPPLY STACK, ELEVATING MEANS FOR SUPPORTING THE SUPPLY STACK, A FIRST MEANS FOR HOLDING DOWN A MARGINAL FACE PORTION OF A TOPMOST BLANK IN THE STACK, MEANS SUPPORTING SAID HOLDING MEANS FOR MOVEMENT OUT OF AND INTO HOLDING CONTACT WITH THE MARGINAL FACE PORTION OF THE TOPMOST BLANK IN THE STACK, A SECOND HOLDING MEANS, MEANS FOR SUPPORTING THE SECOND HOLDING MEANS FOR MOVEMENT INTO AND OUT OF HOLDING CONTACT WITH THE MARGINAL FACE PORTION OF THE SUCCEEDING BLANK, MEANS FOR ALTERNATELY ACTUATING THE RESPECTIVE HOLDING MEANS SO THAT ONE IS BEARING UPON THE MARGINAL FACE PORTION OF A BLANK WHEN THE OTHER IS OUT OF HOLDING POSITION, MEANS FOR ACTUATING THE ELEVATING MEANS, AND MEANS RESPONSIVE TO SAID FIRST HOLDING MEANS FOR EFFECTING OPERATION OF THE ELEVATING MEANS AFTER REMOVAL OF A FEW OF THE BLANKS TO MAINTAIN THE BLANKS IN THE STACK IN POSITION TO BE REMOVED BY SAID BLANK REMOVING MEANS.

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