US3448978A - Paper-feeding method and machine - Google Patents

Description

June 10, 1969 G. A. GIBSON 3,448,973

PAPER-FEEDING METHOD AND MACHINE Filed March 15. 1967 Sheet INVEN'IUR. GEORGE A. GIBSON FIG 2 BY MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS June 10, 1969 GIBSON 3,448,978

PAPERFEEDING METHOD AND MACHINE Filed March 13, 1967 Sheet 5 or 5 INVENTOR.

GEORGE A. GIBSON BY MORGAN, FINNEGAN, DURHAM 8| PINE ATTORNEYS June 1969 G. A. GIBSON 3,448,978

PAPER-FEEDING METHOD AND MACHINE- Filed March 13, 1967 Sheet 3 of 5' I N VEN 10A.

GEORGE A. GIBSON MORGAN, FINNEGAN, DURHAM 8r PINE ATTORNEYS June 10, 1969 G. A. GIBSON PAPER-FEEDING METHOD AND MACHINE Sheet Filed March 15, 1967 INVENTOR.

GEORGE A. GIBSON MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS June 10, 1969 G. A; GIBSON 3,4 8,978

PAPER-FEEDING METHOD AND MACHINE Filed March 15. 1967 Sheet 14)! 5 GEORGE A. GIBSON MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS United States Patent 3,448,978 PAPER-FEEDING METHOD AND MACHINE George A. Gibson, 365 W. 20th St.,

New York, N.Y. 10011 Filed Mar. 13, 1967, Ser. No. 622,663 Int. Cl. B65h 5/08, 5/06, 3/08 US. Cl. 271-11 3 Claims ABSTRACT OF THE DISCLOSURE wheel on its upward return stroke, whereupon vacuum to the suction arm is broken and the suction wheel and pullout rollers transport the sheet away from the paper supply. Each sheet is flexed as it is drawn past the overhanging lip, so as to break any suction force permeating the topmost sheet of paper and thereby individually separate the sheets of paper from one another.

The paper supply is carried on a table which is elevated through gearing mechanism in response to a change in the paper level to thereby maintain the paper supply at a substantially constant level. A stopcock valve automatically opens and closes in synchronization with the suction arm to apply a vacuum to the suction wheel only at predetermined intervals of time.

Backgrormd and objects of the invention The present invention relates generally to paper feeding machines and methods and relates more particularly to a novel method for feeding paper and to a novel paper feeding machine for carrying out the novel method having certain new and improved mechanisms for automatically controlling the level of the paper supply carried by the machine and for picking and transferring the successively topmost sheet of paper from the supply to a desired location.

It is desirable in many facets of the paper and printing industries to be able to automatically feed one sheet of paper at a time from a supply of sheet paper stock so that other operations may be carried out on the individual sheets, as desired. Heretofore, automatic paper feeding machines have suffered from unreliable operation in that two or more sheets are often removed together, jamming subsequent operations, or awkward and unreliable mechanisms have been employed in attempts to separate the paper sheets so that they may be removed individually.

It is therefore an object of this invention to provide a new and improved paper feeding method and apparatus.

Another object of this invention is to provide a new and improved paper feeding method which transfers a single sheet of paper at a time from a supply of sheet paper stock with improved ease and reliability of operation.

Another object of this invention is to provide a new and improved paper feeding method for separating the individual sheets in a pile of sheet paper stock and for positively feeding the sheets, one at a time, to the desired location.

Another object of this invention is to provide a new and improved paper feeding method whereby sheet paper stock is fed from a supply by firstly, suspending the 11ppermost sheets in the supply with an air blast; secondly, picking and transferring the topmost sheet from the supply to transport means, flexing the sheet as it is transferred; and, thirdly, transporting the picked sheets, one at a time, to the desired location.

Another object of this invention is to provide a new and improved paper feeding method wherein the sheet paper supply is automatically maintained at a substantially constant level.

Another object of this invention is to provide a new and improved paper feeding machine which automatically picks up and transfers a single sheet of paper at a time from a supply of sheet paper stock with. improved ease and reliability of operation.

Another object of this invention is to provide a new and improved paper feeding machine having new and improved means for separating the individual sheets in a pile of sheet paper stock and for providing a positive pick-up and transfer of the topmost sheet to transport means which deliver the individual sheets to the desired location.

Another object of this invention is to provide a new and improved paper feeding machine having means for automatically controlling the level of the supply of sheet paper stock, such that the topmost sheet is continuously maintained at a substantially constant level.

Another object of this invention is to provide a new and improved paper feeding machine which includes valve means which automatically open and close in synchronization with suction' paper pick-up and transport means only at predetermined intervals.

Another object of this invention is to provide, in a paper feeding machine having new and improved positive paper pick-up means and transport means for delivering individual sheets of paper to a desired location, means for causing the pick-up means to release the sheet of paper upon its being transferred to the paper transport means.

Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities, steps, processes and combination pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, steps, combinations and improvements herein shown and described.

Summary 0 the invention Briefly described, the method of the present invention for feeding paper from a supply of sheet paper stock is primarily characterized by firstly suspending the uppermost sheets in the supply with an air blast; secondly, picking and transferring the topmost sheet from the supply to transport means, flexing the sheet as it is transferred; and, thirdly, transporting the picked sheets, one at a time, to the desired location. Also, the method contemplates automatically maintaining the sheet paper supply at a substantially constant level and automatically synchronizing the application of vacuum to a transport suction wheel with the transfer of a sheet of paper thereto by the paper picker.

The paper feeding machine of the present invention is primarily characterized by novel means for individually separating the sheets of paper in a sheet paper supply; for feeding individual sheets one at a time from the supply, including means for positively picking up and carrying the successive top sheets to transport means which, in turn, deliver the sheets to the desired location; for automatically controlling the sheet paper supply at a substantially constant level; and for automatically transmitting a vacuum to the transport means at predetermined intervals in synchronization with the pick-up means.

A plurality of air jet tubes direct a blast of air against the forward edge of the sheet paper supply so as to upwardly lift and suspend the several uppermost sheets. The forward edge of the topmost sheet bears against the underside of an overhanging lip located below the lowest level of the transport means. The successive topmost sheet in the supply is picked up by an oscillating suction arm and drawn past the overhanging lip as it is carried to the transport means, whereupon the vacuum to the arm is broken and the sheet is delivered by the transport means to the desired location. The oscillating suction arm provides a positive pick-up of the topmost sheet of paper on each of its downward strokes and the flexing of the paper sheet as it is drawn past the lip breaks any suction force which may permeate the topmost sheet, thereby reliably transferring only a single sheet at a time to the transrmrt means.

The transport means include a rotating suction wheel and two or more sets of pull-out rollers. The suction wheel firmly grasps the sheet of paper upon its release from the suction arm and transports it to pull-out rollers which, in turn, deliver the sheet to the desired location.

The sheet paper supply is maintained at a substantially constant level by stacking the sheets on a table which is elevated by gearing mechanism driven by a ratchet-andpawl in response to a change in the level of the paper. A paper feeler finger and dog-arm depressor are secured to the same oscillating shaft on which the suction arm is mounted, the dog-arm in vertical alignment, but normally out of contact, with the pawl. Upon a lowering of the paper supply level, due to the removal of one or more sheets therefrom, the paper feele'r finger permits the oscillating shaft to rotate over a greater arcual distance, whereupon the dog-arm contacts and depresses the pawl into engagement with the ratchet wheel, actuating the table elevation mechanism.

Advantageously, the application of a vacuum to the transport suction wheel is automatically synchronized with the oscillating suction arm so as to apply a vacuum only from a time shortly prior to the time the suction arm reaches the end of its upward stroke to a time just after the sheet of paper is passed to the pull-out rollers.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Brief description of the drawings FIGURE 1 is a fragmentary elevation view, partly diagrammatic and partly in section, of a side frame panel of a paper feeding machine embodying the apparatus of this invention, the view illustrating, in particular, an embodiment of the drive mechanism for automatically raising the paper storage table and for driving the paper transport rollers;

FIGURE 2 is a fragmentary elevation view, partly diagrammatic and partly in section, of the opposite side frame panel for the paper feeding machine of FIGURE 1, the view illustrating the drive mechanism for the paper transport suction wheel;

FIGURE 3 is an exploded, fragmentary perspective view, partly diagrammatic, of the paper feeding apparatus of FIGURES 1 and 2, the view depicting the transverse arrangement of the ratchet-and-pawl mechanism, paper feeler finger, paper transport suction wheel, and the paper pick-up mechanism;

FIGURE 4 is a view in front elevation of an embodiment of the air manifold unit for regulating the suction applied to the paper transport suction wheel, and of the mechanism for driving the paper pick-up finger and controlling the level of the paper storage table of the paper feeding machine of this invention;

FIGURE 5 is an elevation view, taken from the left side of FIGURE 4;

FIGURE 6 is a fragmentary elevation view, partly diagrammatic and partly in section, illustrating the details and operation of the positive paper pick-up finger;

FIGURE 7 is a fragmentary perspective view, partly diagrammatic, illustrating the air manifold unit and air jets for propelling a blast of air against the upper, forward edge of the paper supply carried by the paper storage table depicted diagrammatically in FIGURE 1; and

FIGURE 8 is a longitudinal sectional view illustrating the details of a typical air jet of FIGURE 7.

Description 0 the preferred embodiment Referring now more particularly to the embodiment of the apparatus of the invention shown in the accompanying drawings, there is illustrated a paper feeding machine, indicated generally by reference numeral 1, having opposed, upright side frame panels 2, 3 between which a paper storage table (not shown), carrying a supply of sheet paper stock 5 (see FIGURE 6), is suitably supported for upward and downward movement, more fully described hereinafter. Advantageously, suitable conveyor means, indicated generally by reference numeral 6, is provided immediately forwardly of the machine for carrying the individual sheets of paper delivered thereto to desired locations for the performance of subsequent operations thereon.

The driving means for the paper feed and elevator mechanism, as best depicted diagrammatically in FIG- URE 1, and as here preferably embodied, comprises a primary sprocket wheel 10, suitably mounted for rotation with a primary drive shaft 11 which, in turn, is suitably journalled at its outer ends for rotation in bearing housings (not shown) carried by the side frame panels 2, 3. Sprocket wheel 10 is chain driven by a suitable motor (not shown) and roller chain 12, at the desired rotational speed.

A pinion gear 15 is also mounted on primary drive shaft 11 so as to be driven thereby and, in turn, meshes with and serves to drive idler gear 16, mounted for rotation with an idler stud shaft 17, suitably mounted to frame panel 2. Idler shaft 17 also carries a sprocket 1 8 operatively coupled with and serving to drive a sprocket 19 by means of roller chain 20. Sprocket 19 is similarly mounted for rotation with a second idler stud shaft 21, suitably mounted to frame panel 2. Idler shaft 19 also carries a pinion gear 22 which meshes with and serves to drive pinion gear 23 secured to drive shaft 25, the latter suitably journalled for rotation in a bearing housing (not shown) carried by frame panel 2. Thus, the rotation of drive shaft 11 is transmitted through the idler shafts 17 and 21 to thereby drive the shaft 25 at a uniform rotational speed. It will be understood that the desired speed of rotation of shaft 25 may be obtained by varying the gear ratios of pinion gears 22, 23.

In accordance with the invention, means are provided for automatically controlling the level of the supply of sheet paper stock, such that the topmost sheet is con tinuously maintained at a substantially constant level. To this end, a crankshaft 26 is pivotally connected at one end by suitable linkage (not shown) secured to drive shaft 25 so as to be driven thereby in a generally up and down reciprocating movement. The opposite end of crankshaft 26 is pivotally connected by a pin member 27 to a pawl holder 28, advantageously in the form of a generally rectangular plate. Pawl holder 28 is mounted for rotation about a shaft 30, the latter being suitably journalled for rotation in a bearing housing (not shown) carried by frame panel 2. It will thus be seen that reciprocating crankshaft 26 continuously drives pawl holder 28 in a back-and-forth oscillating motion about shaft 30.

A pawl 31 is pivotally mounted on pawl holder 28 about pivot pin 33 and is adapted to engage and thereby drive ratchet wheel 35, secured to shaft 30 adjacent pawl holder 28. Pawl 31 is normally urged out of engagement with ratchet 35 by means of tension spring 36, the latter pivoting the pawl upwardly and outwardly away from the ratchet wheel. At predetermined times, in response to a change in the level of the paper supply carried by the machine, a dog arm 50 contracts and depresses pawl 31 into engagement with ratchet 35, as will be more fully described hereinafter, whereby the oscillating motion of pawl 31 intermittently unidirectionally rotates ratchet 35 and, consequently, shaft 30. A stop pin 34 prevents dog arm 50 from further depressing pawl 31 after the latter has engaged ratchet 35.

"A sprocket wheel 38 is also mounted on shaft 30 so as to be driven thereby and is operatively coupled with and serves to drive a sprocket 40, mounted for rotation on idler shaft 41, through roller chain 39. Shaft 41 also carries and serves to drive a pinion gear 42 in meshing engagement with a pinion gear 43 secured to a worm shaft 44. The worm gear 45 of shaft 44 in turn meshes with and serves to drive worm 'wheel 46, secured to one end of an elevator shaft 47. A sprocket-and-chain arrangement is mounted to the other end of shaft 48 in operative association with a similar sprocket (not shown) on the paper storage table (not shown), whereby rotation of shaft 48 serves to elevate the paper storage table. Advantageously, worm shaft 44 terminates in a crank for manual setting of the paper table at the beginning of a run, more fully described hereinafter.

It will be apparent from the foregoing that the elevation of the paper storage table, and consequently the level of the supply of sheet paper stock being fed by the machine, is controlled by the intermittent, unidirectional, rotation of ratchet 35, driven by oscillating pawl 31. Pawl 31 is, in turn, actuated into engagement with, and thereby serves to drive, ratchet at predetermined intervals, in response to a change in the level of the paper supply 5.

To this end, as previously indicated, there is provided a dog arm 50 secured to a pick-up shaft 51, the latter being suitably journalled for rotation in bearing housings (not shown) carried by side frame panels 2, 3. As best seen in FIGURES 1 and 3, dog arm 50 is secured in a position longitudinally of shaft 51 so as to be in vertical alignment with pawl 31.

Shaft 51 is normally urged to rotate in a clockwise direction by the force of tension spring 52, fixed at one end to a pin 53 mounted on the side frame panel 2, against clip 54 secured to the shaft 51 (FIGURE 4). Also secured for rotation with shaft 51 is a follower arm 55, the latter being in substantially continuous engagement with a roller 56 carried at the upper end of a vertically extending lever 57.

Lever '57 is pivotally mounted near its lower end about a stud shaft 58 extending from the side frame panel 2 and, similarly to shaft 51, is normally urged in a clockwise direction by the tension force of spring 59 extending between a pin 60 mounted on frame panel 2 and the lower end thereof. A rotating cam 61 is secured to driven shaft 25 so as to bear against a roller 62 mounted on lever 57 and serves to drive the lever, in combination with the action of tension spring 59, in an oscillating motion about stud 58. It will be seen that as lever 57 oscillates about stud shaft 58, roller 56 swings back and forth in an arcual path beneath follower arm 55. Thus, on alternate strokes of the lever, roller 56 works against the tension of spring 52 to thereby, in turn, drive pick-up shaft 51 in an oscillating motion about its axis of revolution.

A paper feeler finger 65 is also secured to pick-up shaft 51 with its free end resting on the topmost sheet of the supply of paper carried by the machine. Feeler 65 is secured to shaft 51 in a predetermined circumferential position with respect to the circumferential position of dog arm 50 on shaft 51 such that, when the topmost sheet of paper is at the desired level, feeler 65 stops the rotation of shaft 51 and dog arm 50 does not depress pawl 31, whereby the latter remains out of engagement with ratchet wheel 35. Upon the removal of a few sheets of paper from the supply 5, finger 65 must reach a lower level before the rotation of shaft 51 is stopped and, consequently, dog arm 50 contacts and depresses pawl 31 into driving engagement with ratchet wheel 35, thereby elevating the paper storage table in the manner previously described.

Advantageously, and as here preferably embodied, feeler finger 65 is located on pick-up shaft 51 near the side frame panel 2, so as to minimize the effect of the disturbance caused by the paper pick-up and transfer mechanism located centrally of the machine, as will be more fully described hereinafter.

In accordance with the invention, means are provided for separating the individual sheets of the supply of sheet paper stock and for providing a positive pick-up and transfer of the topmost sheet to transport means which, in turn, deliver the individual sheets to the conveyor 6, or to any other desired location.

To this end, the sheet paper supply 5 is carried on the storage table with the forward edges of the individual sheets substantially fully exposed, the sheets advantageously being held in place by two or more upstanding rails, one such rail illustrated at 70 in FIGURE 6. A plurality of vertically extending tubes 71 are located opposite the forward edges of the sheet paper supply and generally centrally thereof, and are each provided with small openings 72 near their upper ends. Tubes 71 terminate at their lower ends in a manifold 73, in turn connected to a source of air pressure (not shown) by flexible hose conduit 74. It will thus be seen that tubes 71 conduct and direct a blast of air against the forward edges of the upper portion of the sheet paper supply, thereby slightly separating the top few sheets of paper from each other (FIGURES 6 and 7). Advantageously, a paper contact finger 68 may be provided, suitably mounted on horizontal shaft 69, so as to ride on the surface of the topmost sheet of paper and thereby tend to hold down the individual sheets of paper in the supply stock and guide them as they are picked up and transported away, as is more fully described hereinafter.

Tubes 71 extend through openings in a horizontal bracket 75 provided with transverse set screws 76 so as to be vertically adjustably mounted opposite the paper supply. Also advantageously, manifold 73 is provided with a manually rotatable regulator disc 77 for regulating the force of the air blast emitted by tubes 71, as will be understood to those of ordinary skill in the art.

A bracket 78, having a horizontal lip 79 overhanging the supply of sheet paper 5, is suitably secured to the upper end of one of said rails 70 so as to limit the distance the topmost sheets are raised by the force of the air blast from tubes 71. Preferably, lip 79 is located in direct alignment with pick-up arm 80, the latter more fully described hereinafter. Lip 79 also serves a significant part in assuring that only a single sheet at a time is withdrawn from the supply, as will be more fully described hereinafter.

As previously indicated, positive pick-up means are provided for picking up and transferring the topmost sheet of paper from supply 5 to transport means. To this end, a pick-up ar-m, indicated generally by reference numeral 80, is secured to oscillating pick-up shaft 51 by clamp 81. Pick-up arm 80 comprises a generally tubular member 82 extending forwardly of clamp 81, the hollow interior thereof communicating with a flexible hose conduit 83 connected to a source of vacuum (not shown). Intermediate of pick-up arm 80 and the vacuum source, a pressure regulable manifold 84 is provided for regulating the vacuum communicated to the pick-up arm, as will be understood to those of ordinary skill in the art.

Pick-up arm 80 is provided with two openings on the underside of the tubular member 82, the first opening being located near the forward end thereof and receiving a suction cup 85 having a conically recessed face 86 terminating in a conduit 87 which extends through the base of the cup to communicate the interior of arm 80 with the cup face 86. The second opening is located at 90 and is normally closed by a disc pad 91 mounted on the end of a flat spring clip 92, the latter in turn being suitably secured to the undersurface of member 82.

It will be understood from the foregoing that pick-up arm 80 is driven in an oscillating motion by shaft 51 and that, by reason of the vacuum communicated thereto, at the end of each downward stroke, suction cup 85 picks up the topmost sheet of paper from the supply 5. On the upward, return stroke of arm 80, the sheet held by the suction cup is drawn past the overhanging lip 79 and transferred to the transport means. As the sheet is drawn past lip 79, it is caused to flex or bend, thereby insuring that any vacuum permeating the topmost sheet is broken and that only a single sheet at a time is carried to the transport means.

Advantageously, suction cup 85 is formed from a material, such as rubber or an equivalent thereto, having suflicient flexibility so as to substantially fully conform to the bending or flexing of the sheet as it is drawn past lip 79, thereby insuring that a vacuum is continuously maintained on the surface of the sheet.

Immediately prior to the end of each upward stroke of pick-up arm 80, the vacuum created on the face of the suction cup 85 is broken, thereby releasing the sheet of paper to transport means, more fully described hereinafter. To this end, as here preferably embodied, a rod 95 is suitably secured to horizontal shaft 69, extending between frame panels 2, 3, so as to extend angularly I downwardly adjacent pick-up arm 80. Rod 95 terminates at a point slightly below the upper limit of travel of pickup arm so as to contact and depress spring clip 92, thereby forcing pad 91 away from opening 90 in tubular member 82 and breaking the vacuum applied to the sheet by suction cup 85.

As here preferably embodied, the transport means for receiving the individual sheets from pick-up arm 80 and delivering the sheets to the desired location comprises a suction wheel 100 and two sets of pull-out rollers, one such set being shown at 101, 102. Advantageously, suction wheel 100 has a hollow interior communicating a double row of slotted openings 103, located on either side of a diametrically recessed portion 104 on the peripheral surface thereof, with a plurality of holes 105, arranged in a circular row on one side 106 of the wheel.

Suction wheel .100 is secured for rotation with a drive shaft 110 which, in turn, is suitably journalled at its outer ends for rotation in bearing housings (not shown) carried by the side frame panels 2, 3. A sprocket wheel 111 is also secured to, and serves to drive, shaft 110' by means of roller chain 112, operatively coupling sprocket 111 with a sprocket 113, the latter being mounted to an idler shaft 114 suitably journalled for rotation in side frame panel 3. Shaft 114 is driven by pinion gear 115 in meshing engagement with pinion gear a secured to the primary drive shaft 11 (FIGURE 2).

Each set of pull-out rollers includes a lower, driver roller 101, secured to primary drive shaft 11, and an upper, idler roller 102. Roller 102 is suitably journalled for rotation in a bracket 116 linked to horizontal shaft v118 extending between the side frame panels of the machine. Advantageously, driven roller 101 is constructed from a steel material while idler roller 102 has a rubber material formed about its periphery so as to insure positive delivery of the sheet paper to the desired destination. Also advantageously, suction wheel 100 and pull-out rollers 101, 102 are driven at the same surface speed whereby as soon as each sheet of paper is passed to the pull-out rollers the suction applied thereto by wheel 100 may be terminated in a manner to be described hereinafter.

An open-ended conduit member 120 is spring-pressed by compression spring 121 into tight-fitting abutment at a radial position on side 106 of suction wheel 100 so as to communicate a source of vacuum (not shown) from flexible hose conduit 122 to holes 105 and, thence, peripheral slots 103.

Intermediate conduit and the vacuum source, a manifold 125 is provided for regulating the amount of the vacuum and for turning the vacuum on and off. To this end, manifold 125 is provided with an opening 126 covered by a rotatable disc 127 having a plurality of holes therein of varying diameter. It will be apparent that the amount of vacuum conducted through the manifold may be progressively decreased by rotating the disc from a position completely covering opening 126 (FIGURE 4) to a position wherein the largest hole in the disc is in registry with opening 126.

A second opening 128 is provided in manifold 125 and is adapted to be opened or closed by manually rotating stopcock 129 into and out of registry therewith. It will be understood that with stopcock 129 in registry with opening 128, a vacuum is continuously created at the surface of suction Wheel 1100.

Advantageously, and as here preferably embodied, the suction at the peripheral surface 103 of suction wheel 100 is applied from a time shortly prior to the time pickup arm 80 reaches the end of its upward stroke to a time just after the sheet of paper is passed from the suction wheel to the pull-out rollers 101, 102. To this end, manifold 125 is provided with a third opening 130 adapted to be automatically opened and closed by a rocker stopcock 131 in synchronization with the oscillating motion of pick-up arm 80. Thus, rocker stopcock 131 is pivotally mounted at one end to stud shaft 58 and is normally urged into a positon of registry with opening 130 by tension spring 132. A rotating cam 133 is fixed to driven shaft 25 forwardly of cam 61 and is adapted to engage roller follower 134 mounted to stopcock 131 and thereby pivot the stopcock out of registry with opening 130, breaking the vacuum applied to suction wheel 100. It will be understood that, when it is desired to manually control the vacuum applied to the suction wheel, opening 130 may be permanently closed by locking stopcock 135 against the upper, curved lip 136 of rocker stopcock 131, stopcock 135 thereby covering the opening.

It will be apparent from the foregoing that the operation of the previously described embodiment of the paper feeding machine of the present invention is as follows.

The primary drive shaft 11, through chain and gear mechanisms, continuously rotates the suction wheel 100 and pullout rollers 101, 102, preferably at the same surface speed. Drive shaft 25, also driven by shaft 11 through chain and gear mechanisms, serves to continuously oscillate both pawl holder 28, through reciprocating crank shaft 26, and pick-up shaft 51, through cam 61, lever arm 57 and lever cam follower 55. The plurality of air jet tubes 71 directs a blast of air against the forward edge of the sheet paper supply 5 so as to upwardly lift and suspend the several uppermost sheets, the forward edge of the topmost sheet bearing against the underside of overhanging lip 79.

Suction arm 80 is continuously driven in an oscillatory motion by oscillating shaft 51, picking up the topmost sheet in the supply 5 on its downward stroke and carrying the sheet to suction wheel 100 on its upward, return stroke. As the forward edge of the sheet is drawn past the overhanging lip '79, the sheet is caused to flex or bend, which breaks any suction force permeating through the sheet to the next sheet. In this manner, only a single sheet at a time is carried to the suction Wheel to be subsequently fed from the machine.

The upward stroke of suction arm 80 advantageously terminates within the diametrically recessed portion 104 of suction wheel .100, whereupon rod 95 deflects spring clip 92 to break the vacuum applied to suction cup 85 and release the sheet to the bottom peripheral surface of the suction Wheel. The continuously rotating suction wheel propels the sheet in a substantially horizontal direction to pull-out roller 101, 102 which, in turn, transport the sheet to the desired location.

Upon the removal of a few sheets of paper from the supply, feeler finger 65 must reach a lower level before it contacts the paper supply and consequently, dog arm 50 depresses oscillating pawl 31 into engagement with ratchet wheel 35, thereby elevating the paper storage table until the topmost sheet is again at the desired level.

Also, as preferably opera-ted, suction wheel 100 and pull-out rollers 101, 102 are driven at corresponding surface speeds and the Vacuum to wheel 100 is applied only during the predetermined interval of time previously mentioned, providing a quieter and smoother feeding action.

The invention in its broader aspects is not limited to the specific embodiment herein shown and described but departures may be made therefrom within the scope of the accompanying claims, without departing from the principles of the invention and Without sacrificing its chief advantages.

What is claimed is:

1. In an apparatus for feeding individual sheets of paper from a supply of sheet paper stock, the improvements therein which comprise:

means for individually separating the sheets of paper in said sheet paper supply;

means for feeding said individual sheets of paper one at a time from said supply to a desired location, including means for positively picking up and carrying the successive top sheets to transport means, said transport means including a rotatable suction Wheel and a pair of pull-out rollers for delivering said sheets to said desired location; and means for automatically transmitting a vacuum to said suction wheel at predetermined intervals in synchronization with said positive pick-up means.

2. Apparatus for feeding individual sheets of paper from a supply of sheet paper stock comprising:

table means receiving said paper supply,

said table means including lip means extending inwardly from an edge of said table means and in spaced relation thereto;

means directing a blast of air against said paper supply so as to at least partially separate several of the uppermost sheets therein, one edge of the topmost sheet bearing against said lip means;

means for feeding said individual sheets of paper one at a time from said supply to a desired location,

including first and second suction means,

said first suction means picking up and carrying said topmost sheet to said second suction means, drawing said edge of said sheet past said lip means, said first suction means comprising a continuously oscillating hollow arm member having a suction cup at the distal end thereof and a source of vacuum communicated to said suction cup,

said oscillating arm picking up said topmost sheet on each downward stroke and carrying said sheet to said second suction means on each upward stroke; said second suction means comprising a rotatable Wheel and a source of vacuum communicated to the peripheral surface thereof, and further including at least a pair of pull-out rollers for receiving said sheet from the suction wheel and delivering said sheet to said desired location; means for breaking the vacuum applied to said first suction means simultaneously With the arrival of said topmost sheet at the suction Wheel of said second suction means; means responsive to a change in the level of said paper supply for elevating said table means a corresponding distance, thereby maintaining said paper supply at a substantially constant level; and

said suction wheel only from a time just prior to the arrival of said sheet thereto until said sheet is transported thereby to said pull-out rollers. 3. A method for feeding individual sheets of paper from a supply of sheet paper stock comprising the steps of:

directing a blast of air against said paper supply so as to at least partially separate several of the uppermost sheets therein; applying a first source of vacuum to the topmost sheet of said paper supply so as to pick up said sheet; flexing said sheet as it is picked up from said paper pp y; applying a second source of vacuum to said sheet so as to transport said sheet to a desired location; breaking said first source of vacuum simultaneously with the application of said second source of vacuum to said sheet; automatically providing said second source of vacuum at predetermined intervals in synchronization with the breaking of said first source of vacuum; and automatically controlling said sheet paper supply at a substantially constant level.

References Cited UNITED STATES PATENTS valve means automatically transmitting said vacuum to k

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