US3159397A

US3159397A - Document separating apparatus

Info

Publication number: US3159397A
Application number: US244108A
Authority: US
Inventors: Kenneth F Zyber
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1962-12-12
Filing date: 1962-12-12
Publication date: 1964-12-01
Anticipated expiration: 1981-12-01

Description

Dec. 1, 1964 K. F. ZYBER 3,159,397

DOCUMENT SEPARATING-APPARATUS Filed Dec. 12, 1962 3 Sheets-Sheet 1 Fig. 1.

INVENTOR KENNETH E ZYBER. Y

ATTORNEY.

Dec. 1, 1964 Filed 'Dec. 12, 1962 Fig. 2.

K. F. ZYBER DOCUMENT SEPARATING APPARATUS 3 Sheets-Sheet 2 INVENTOR KENNETH E ZYBER.

ATTORNEY 1964 K. F. ZYBER DOCUMENT SEPARATING APPARATUS 3 Sheets-Sheet 3 Filed D60. 12, 1962 u mwgwx 5 R 8 w J m a 5 my 2 w 2 a :w n n Mn 1 H a v w M M M M I H ATTORNEY.

United States Patent 3,159,3h7 DGCUIWENT SEPARATENG APPARATU$ Kenneth F. Zyber, Novi, Mich, assignor to Burroughs Corporation, etroit, Mich, a corporation of Miehigan Filed Dec. 12, E62, er. No. 244,108 13 Claims. (til. 271-34) This invention relates to document handling apparatus, and, more particularly, to apparatus for demand operated document feeders feeding documents at a high rate of speed.

The invention is specially suited for use with a demand operated, high speed friction feeder feeding documents, such as punched tabulating cards, one at a time on demand through the feed exit of a card hopper to power driven accelerating drive rollers from which the card is fed to another destination.

The invention has among its objects to provide, in a demand operated document feeder feeding documents from a stack of documents in a feed hopper, a document separator structure that effectively separates a document fed on demand by the feeder and prevents a subsequent document from being carried therewith to the drive rollers until a subsequent operation of the demand feeder.

A related object is to provide, in apparatus of the above character, a document separator structure in which the driving force is applied through the separator area for driving the document therethrough and separating it from adjacent documents, which are effectively prevented by the separator structure from progressing through the separator area in both the feeding and non-feeding operating modes of the friction feeder.

Another object is to provide a document separating structure for a demand operated feeder providing both frictional separation and fixed throat separation.

A specific object is to provide in apparatus of the above character a variable gap separator providing two different separating gaps in the feeding and non-feeding modes of the feeder.

A related object is to provide a frictional separator structure for a demand operated friction feeder in which the separator is not subjected to any wear from the friction feeder in the non-feeding mode of the feeder.

Another object is to provide a document separator structure for accomplishment of the foregoing ends which is of simple construction, is possessed of relatively durable wearing qualities and long service life and enables effective separating action for a demand feeder without restricting the speed rate thereof.

The above and other objects together with the features, advantages and manner of accomplishment thereof will appear more fully from a consideration of the following detailed description and drawings, wherein:

FIG. 1 is a plan View on a reduced scale and with parts broken away of a card handling and friction feeder apparatus incorporating the document separating structure of the present invention;

FIG. 2 is a sectional elevation view taken along the line 22 of FIG. 1 with some parts broken away;

FIG. 3 is an enlarged view with parts broken away of a portion of the feeder and separator section of FIG. 1 and illustrated in a feeding position;

FIG. 4 is a portion of FIG. 3 illustrating the separator structure in the non-feeding position of the feeder;

FIG. 5 is a perspective view of a stripper guide plate in the feeder and separator section of FIG. 1; and

FIG. 6 is a simplified electrical control circuit diagram for controlling the operation of the feeder.

Referring to the drawings, a portion of a document handling card feeder and reader mechanism 10 is shown 3,l5,397 Patented Dec. 1., 1964 in FIG. 1 in which a stack 12 of documents, such as punched cards, is supported edgewise in a feed hopper 14 and successively presented to a feeding station 16 from which the cards are fed singly on demand past a reading station 18 to a turn around guide roller 20 from which they are stacked in a stacking hopper 22 in the same order in which they were fed.

The feed hopper 14 includes a stationary floor plate 28 and an oscillatable floor plate 29 mounted on a base casting 26; a left end wall formed by an upstanding, rearwardly extending stripper or guide plate 32; a laterally extending edge guide 33 slidably mounted on the movable floor plate 29; a rearwardly extending pusher plate 36 overhanging the hopper edge guide and floor plates; and

an empty hopper switch 37 having a card sensing actuator 38 projecting through an opening in the stripper plate. The pusher plate 36 is pivotally mounted and supported from an upstanding bracket 40, which is secured to a bored pilot or bearing block 42 coaxially slidably received on a laterally extending cylindrical guide tube 44 that is mounted on the base casting 26. The pusher plate is urged leftwardly toward the stripper plate by a vertically spaced pair of horizontally extending

cables

45, 46 connected respectively between the block 42 and a lug 47 on bracket 4%) and to coiled

spring tensioning devices

48 and 49 which are mounted from the base plate and are tensioned as the pusher plate 36 is moved manually rightwardly to receive a stack of cards.

The feeder 16 is disclosed and claimed in copending US. patent application S.N. 244,030 filed December 12, 1962, in the name of Robert 1. Barber, for Document Handling Apparatus, and includes a constantly driven, endless feed belt Bil, which is formed of rubber and passes over one face of a belt back-up member or platen 52. Platen 52 is displaced behind, but is movable upon demand from a solenoid actuator assembly 54 past the stripper plate 32 to position the belt for frictional engagement with the first or leftmost card of the stack. The continuously traveling belt drives the card edgewise and rearwardly between a spaced pair of

upstanding guide plates

56, 58 forming a document guideway and past a separator and throat block region 60 in the feed exit of the hopper. From the feed exit the card is fed by the feeder into the bight of a card pull-out, accelerating drive roller assembly 62 and past a photo-optical card detector 64, which detects the presence of the card and de-energizes the solenoid actuator 54 to retract the belt carrying platen from the card stack. From the pull-out drive roller assembly, the card is transported thereby between the guide plates and past the card reading station 18 by a cotton belt 65, drive roller 66 and cooperating idler, belt tensioning, and

pressure rollers

67, 68 and 69, 70 and then around the turn around guide roll 20 from which the card is directed into the card stacker 22.

The feed belt 55) is driven in acounterclockwise direction from a drive pulley 1&2 secured to the upper end of a vertically extending tubular shaft 104, the lower portion of which below the base casting 26 mounts another pulley 1% which is constantly driven by belt 1&8 from an electric drive motor 110. Spaced rearwardly of the drive pulley 162 is an adjustable idler and belt tensioning pulley 112, and located inwardly and to the right of the drive pulley 162 and crowned idler pulley 112 is a pair of forwardly and rearwardly spaced reverse idler rollers 124 of ribbed configuration corresponding to the ribbed sectional configuration of the feedbelt. *rom the reverse idler rollers 124, the feed belt 50 passes around a pair of forwardly and rearwardly spaced idler rollers 14?. carried by and rotatably mounted on the movable platen 52 which provides a rigid backing surface for the reach of e belt extending between the platen idler rollers 142.

Liv

a Located to the left of and behind the platen is a shock mount and push rod housing 162 of generally hollow, cylindrical formation and having at the end thereor ad acent the, platen a pair of integrally formed face flanges 163, .164 each of which contains in a bored opening 16'? therein a resilient shock mount 165, 1st to which the platen is fastened near its extremities by screws172, as shown in FIG. 3. Projecting beyond the base or lower endo'i the shock mount housing is a pair of integrally formed base flanges 1'76, 177 each having an elongated adjustment slot as 178 therein for reception or a cap screw as 179 through which the housin is adjustably positionably mounted and releasably secured to a subplate L34.v Sub-plate 134 is adjustably mounted on a pedestal block 136 fastened to the base plate as shown inrto. 2.

Located internally of the housing 162 is an upstanding stop and guide block 182 for a resiliently mounted elongated pin or push rod 284 resiliently mounted as shown inFlG, 3 through a spaced pair of inner shock mounts"185, 1t57 similar to the shock mounts 165, 1&6. The right end of the push rod 184 abuts the central portion of the platen 52 and has a threaded opening therein to receive a threaded machine screw Ztll by which the central portion of the platen is positioned and secured to thepushrod and drawn against the inner right shock mount 187. The stop block extends through an elongated slot in the base portion of the housing 162 and is secured at its lower end to the sub-plate 13s by machine screws as shown in PEG. 2. The upper end of the guide spaced pair of shoulders 1%, 1?? located near the opposite endsthereof and bearing against the inner SdOCii mounts as shown. The shoulder ass is received between thexspaced walls of a cross-slot 21% extending transversely of'and formed in the yoke-shaped upper end of the guide solenoid actuator assembly 54 which includes a two-piece cup-shaped, non-magnetic housing 214 having a flanged w baseportion 2l6 with elongated slots therein by which it isajdjustably positioned and secured'to the sub-plate 134 by machine screws, as shown in FIGS. 1 and 3. The solenoid unit includes an electrically energizable, annular field coil224, whichsurrounds a cylindrical, non-magnetic Shaft Z ZS that is supported in spaced sleeve bushings 228 at 'opposite ends of the solenoid housing; Press-fitted on the shaft 226 is an annular armature ring composed of magnetizable soft iron material received in an annular recess or cavity of the coil. Upon energization of the coil, the ring is attracted inwardly of the solenoid coil and carries therewith the reciprocable shaft 226, which is infcontact with the rounded end 2120-5 the push rod 184 through which the platen and belt are displaced transversely of the stripper plate. The armature shaft and push rod are limited in their movement by the central shoulder ass on the push rod limiting against the right side or wall of the cross slot 219 in the stop block 182. The width of the cross slot is such as to permit the feed belt carried by the platen in the actuated position of the latter to project a sufiicient predetermined distance beyond the stripper plate.

The stripper plate 32 is secured to the pedestalblock 136 and, as shown in FIG. 5, includes an elongated slot or opening 15?. therein defined between a spaced pair of converging and longitudinally rearwardly extending flange portions 15%, 155 struck out of the plate. The parallel, vertically'spaced

edges

156, 157 of the flanged portions of the stripper plate overhang the stationary hopper floor plate 28 and are located in a vertical plane in advance of the normal position of the peripheral face of the feed belt in the retracted position of the platen, as shown in FIG. 2. The feed belt and platen are located in the opening 152 and leftwardly behind the flange edges 156, is? so as to be spaced from the first card of the card stack urged against and contacting the flange edges of the stripper plate. Located above the upper flanged portion 154 and spaced longitudinally of the stripper plate are several laterally extending aligning pins 16% fastened to the stripper plate a distance above the feed hopper floor to engage-the upper longitudinal edges of the card stack to maintain the cards in correct vertical registration position for presentation to the feed belt. The surface of the feed belt is ridged as shown at 51, the ridge contacting the surface of a tabulating card between adg'acent rows of perforations therein and being of a width approximately equal to the length or vertical dimension of a punched hole therein.

The rcarwardiy extending rail extensions 15%, 159 of the hanged portions of the stripper plate extend beyond the card stack and past the feed exit of the feed hopper into thesepa'rator area seam, in the retracted or nonl'eeding position of the feed belt, cooperate with the adjacent face of the adjustable' separator block lot to provide a separator throat bloclt having a fixedgap of a width, slightly. greater than the thickness of one card. it will be noted that the longitudinal reach of the feed belt over the face of the platen extends rearwardly beyond the extension rails of the stripper plate and, upon actuation of the platen, is moved transversely of the stripper pl'ateinto the throat gap where it cooperates with the adjacent face, ofthe separator block to provide a separator gap of lesser width than the aforesaid fixed throat gap for effective frictional separation of a card from the stack in the actuated position of the platen in which the feeding force of the belt is supplied through tie separator area.

The separator block 161 or cartridge is formed of a frictional, resilient compressible material, such as cellular urethane foam with an adiprene rubber base and of durable wearing quality, and having a higher coefiicient of friction relative to a card than that between adjacent documents or cards but less than the coelhcient of friction of the rubber feed belt with the cards. The block is shown in FIGS. 4 and 5, as surrounded, on all sides except theinclined separator face 242thereof, by a metallic shield 282, the forward'portion 233 of which p-rivides a hard protective metallic facing for the portion of the block adjacent the rearwardly disposed end of the card stack in the feed hopper. The separator block is included in an assembly which includes a separator pedestal mount 2% that is fastened to the time plate 26 and has stacked thereon'an adjustable intermediate block 292 and a housing 294, which receives the separator block and shield as a cartridge and is mounted on the intermediate block.

The upper surface of the pedestal mount 2% has a raised guide ridge. or key integrally formed thereon and received in a complementary grooved guide or keyway formed in the bottom surface of the intermediate block,

which is adjustably positionable on the pedestal mount by a graduated positioning screw 304- that is longitudinally fixed in the intermediateblock and is threadably received in the cartridge housing. The bottom-surface of the separator block housing has a similar but shorter integrally formed projecting ridge or key received in. a complementary grooved guide or lieyway in the adiacent surface of the adjustable intermediate block and is re- A leasably, clamped thereto by a lock screw 3% threadably of the shipper plate. The separator gap is of sutficient width to allow only one card to pass freely therethrough and is adjusted with tWo cards positioned therein to provide an extremely tight, snug, force fit that would prevent a double card thickness to pass 'therethrough.

For standard tabulating cards of 0.007 inch thickness, the aforesaid fixed gap of the throat block is adjusted within the range of 0.009 to 0.012 inch. The lock screw 302 is then tightened to clamp the setting of the intermediate block 292 to which the separator block housing is secured. The solenoid coil 224 is then energized to actuate the platen and displace the peripheral face of the feed belt a slight distance transversely beyond or in advance of the flange edges of the stripper plate to provide the aforesaid separator gap formed between the separator block and the peripheral face of the feed belt. This gap width is no greater than one card thickness at the most and in the order of 0.005 to 0.007 inch to provide a snug, tight fit with the thickness of a single card positioned between the belt and the separator block. The pressure of the belt and the adjustment of the beltto-separator block gap width are obtained by moving the adjustably positionable sub-plate 134, on which the armature and push rod housings are mounted, relative to the pedestal block 136 on which the sub-plate is mounted, as shown in FIG. 1.

In the feeding position of the belt, the moving face of the belt is in frictional engagement with the card stack to feed a card into and through the feed exit separator area of the feed hopper. The aforesaid separator gap formed between the separator block and feed belt is of such width that the separator block is under pressure against the back of the first card being fed by the belt through the separator area, where there will be generated a separating, scrubbing or retarding force which is greater than the frictional and cohesive forces between adjacent documents but is less than the feeding force supplied from the belt through the separator area. In consequence, should two cards be fed, the second card will be separated from the first by the frictional force of the separator. The inclined face 242 of the separator block assists the separating action between two cards, the sec- 0nd of which will strike the inclined face 285 of the block and be held back thereby as it slips against the back surface of the first card, which presents a lower frictional coefiicient to the second card than that between second card and the separator block. Since the feeding force is applied through the separator area, feeding will be substantially independent of document stifiness and the frictional forces generated from the feeding force in the separating area is effectively utilized to separate adjacent documents.

As the first card passes through the throat gap, it is presented to the bight of the card pull-out and accelerating drive roller assembly 62 which grabs and drivingly aecelerates the separated card at approximately the aforementioned peripheral velocity of 225 inches per second of the feed belt. The drive roller assembly includes a pair of friction-faced drive rollers 244, which are mounted on a shaft 226 driven in a clockwise direction, and a pair of idler rollers 252, which are in yieldable contact with the driven rollers 22d and are freely rotatably mounted in a yoke-shaped housing 256 shown in FIG. 1. Housing 2-56 is resiliently mounted in a shock mount housing container 269 that is adjustably positionable and mounted on the base casting.

Fastened to the upper portion of the

guide plates

56, 58 and located above the driver rollers and idler rollers of the pull-out driver assembly is a mounting for an electric lamp 264 and solar cell 266 which constitute the photoelectric card detector 64. The lamp projects a horizontal light beam through an opening in the guide plate 56 and across the card path upon the solar cell which is positioned behind an opening in the guide plate 58. The detector serves to detect the presence of a card in the bight of the pull-out drive roller assembly and to control the de-energization of the solenoid to retract the feed belt behind the flange edges of the stripper plate, thereby effectively disengaging the feed belt from the card stack and the feeding of a subsequent card by the belt feeder. A simplified control circuit for the solenoid actuator is shown in FIG. 6 in which the output of the solar cell is applied over conductor line 267 to an amplifier 270 having a control relay 272 in the output thereof with the contacts 274 of the relay connected in series with the solenoid coil 224 and the empty hopper switch 37 to a push-button 276 or external demand signal line 268.

After de-energization of the solenoid, the feeding of the separated card is then effected from the pull-out accelerating rollers. However, there is still a portion of the first card in contact with the adjacent card at the time the feed belt is disengaged from the first card. While there will no longer be any feeding force available from the retracted feed belt, there is still a need for preventing the second card from being carried along the interdocument friction, particulanly since the control apparatus controlling the feeder is not calling for a card to be fed at this time. Thus, so long as the second card can be prevented from entering the throat area and progressing into the bight of the continuously driven accelerating rollers while the first card is being fed thereby, the second card cannot be driven by the accelerating rollers and will remain in the position shown in FIG. 3 where it cannot be fed until the platen is again actuated. This separation is eifected from the fixed throat gap now provided between the edges of the stripper plate guide rails and the separator block, which are located as shown in FIG. 4 and spaced apart a distance that is greater than the thickness of one document but less than the thickness of two. Should two cards advance into the separating area and the second card attempt to enter the gap between the stripper rails and the inclined face 242 of the separator block, the second card will attempt to wedge and force against the first and, because of the stiffness of the cards, a normal force will be exerted against the separator block that is sufficient to produce the separating force necessary to retard the second card until the first card is fed completely past the throat block separator area. Thus the second card cannot reach the accelerating rollers, and, being out of contact with the face of the retracted feed belt, is effectively separated and retained in the separating area where it will be held until a subsequent demand signal is applied to the solenoid actuator to actuate the feed belt carrying platen. Since no force is applied to the separator block from the feed belt in the retracted position thereof, the service life of the separator block is considerably increased, conducted tests on which yielding satisfactory separating action therefrom even after over 10 million card feed cycles of the feeder.

It can thus be seen that the invention provides a very effective document separating structure for a demand operated friction feeder that combines the advantages of a fixed throat block separator with a frictional separator without the disadvantages attending such separators. In the feed mode of the feeder, the feeding force is supplied through the separator area whereby the feeding and separating forces are independent of document stiffness. In the non-feed mode, positive separation is still maintained by the fixed throat block while no force is applied through the feeding surface of the belt to the separator, thereby preventing unnecessary wear thereof.

What is claimed is:

l. A document feeding apparatus for edgewise feeding of successive documents stacked in a feed hopper out of the hopper and past the feed exit of the hopper including an elongated stripper plate extending in the direction of the path of feeding and defining a side wall of the hopper, means urging a stack of documents in the hopper against one side of the stripper plate, document separating means located on one side of the feed path in the feed exit of the hopper and spaced from the stripper plate to form a throat block separator therewith having a predetermined gap width related to the thickness of a document, a power driven endless belt on the other side of the stripper plate and having a reach portion extending in the direction of thelongitudinal extent of the stripper plate past the stack of cards and into the feed exit of the hopper, a transversely movable, elongated platen member located behind the aforesaid reach portion of the belt and extending into the feed exit of the hopper, and power operated actuator means coupled to the platen member and operable to'move it and the aforesaid reach portion of the belt a predetermined extent in a direction toward and transversely of the stripper plate to form a frictional separator between the peripheral face of the belt and the separating means spaced from the belt an amount to provide a lesser gap width than that formed between the stripper plate and said separating means in the inactivated position of the platen member.

2. A document feeding apparatus for edgewise feeding of successive documents stacked in a feed hopper out of the hopper and past the feed exit of the hopper including an elongated stripper plate extending in the direction of the path of feeding and defining a side wall of the hopper, means urging a stack of documents in the hopper against one side of the stripper plate, document separating means located on one side of the feed path in the feed exit of the hopper and forming with a portion of the stripper plate a throat block separator having a predetermined gap width greater than the thickness of one document and less than the thickness of two documents, a power driven endless belt on the other side of the stripper plate and having a reach portion extending in the direction of the longitudinal extent of the stripper plate past the stack of cards and into the feed exit of the hopper, a transversely movable, elongated platen member backing and located behind the aforesaid reach portion of the belt and extending into the feed exit of the hopper, and power operated actuator means coupled to the platen memberand operable to move it and the aforesaid reach portion of the belt a predetermined amount in a direction toward and transversely of the stripper plate to form a frictional separator between the peripheral face of the belt and the separating means spaced from the belt an amount to provide a gap Width no greater than the thickness of a single document to be fed therethrough.

3. A document feeding apparatus in accordance with claim 2 above wherein said document separating means is structurally yieldable away from said feed belt by a document being fed thereby in the activated position of the platen member and feed belt.

4. A document feeding apparatus in accordance with claim 2 above wherein said document separating means is composed of resilient material and is spaced from the peripheral face of the belt a distance less than the thickness of one document being fed thereby in the activated condition of the platen member and feed belt.

5. A' document feeding apparatus in accordance with claim 4 above wherein said document separating means is composed of a compressible cellular urethane foam material.

6. A card feeding apparatus for edgewise successive feeding of a stack of cards stacked in a feed hopper including an elongated stripper plate extending in the direction of feeding and defining a side wall of the hopper, means urging a stack of documents in the hopper against one side of the stripper plate, a power driven end-less belt on the other side of the stripper plate, means including a rigid backing member supporting the belt for travel in a path in the direction of the longitudinal extent of the stripper plate and movable transversely of the stripper plate, power operated actuatorimeans coupled to the belt supporting backing member and operable to move it and the belt in a direction transversely of the stripper plate to position the peripheral face of the belt a predetermined distance beyond the said one side of the stripper plate for frictional engagement with the face of the stack, means coupled to and controlling the operation of said power operated means to position the belt in engagement with the stack, a power driven drive roller assembly positioned adjacent the feed exit of the hopper to receive the leading edge of a card still being fed and engaged by said belt, card presence detecting control means detecting the presence of a card fed by the belt to the bight of the drive roller assembly and controlling the operation of said power operated means to retract the belt supporting backing member and the belt to the said other side of the stripper plate, and document separating means located in the feed exit of the feed hopper and cooperating with the feed belt to provide a frictional separating action therewith when the card is being fed thereby and cooperating with the stripper plate'to provide a separating throat therewith when the card is being fed by the drive roller assembly.

7. A card feeding apparatus in accordance with claim 6 above wherein said document separating means provides a different width separating gap when the card is -being fed by the feed belt than when it is being fed by the drive roller assembly.

8. A, card feeding apparatus in accordance with claim 7 above wherein the separating gap provided with the feed belt is of lesser width than that provided with the stripper plate.,-

9. A card feeding apparatus in accordance with claim 8 above wherein the separating gap provided with the cod belt is no greater than the thickness of one card and that provided with the stripper plate is slightly less than the thickness or" two cards,

10. In a document feeding apparatus for demand feeding of documents stacked in a hopper out of the feed exit of the hopper and, including demand operated friction feeding means in the hopper, means urging a stack of documents in the hopper towardsaid friction feeding means, power driven drive rollers receiving a document fed by said friction feeding means for continuing the feeding of a document fed thereto to another destination, a narrow gap friction separator located in the feed exit of the hopper providing a frictional separating action on a document fed on demand from the stack by the friction feeding means, a wide gap throat separator in the same location of the feed exit of the hopper as said friction separator, and means disabling the frictional separating action provided by'said friction separator on the document fed to the power driven rollers when that document is being fed by the drive rollers.

11. A document feeding apparatus for successive feeding of documents stacked in a feed hopper out of the feed exitof the hopper comprising a continuously driven endless feed belt having a reach portion on one side of the document feed path and extending in the direction of the longitudinal extent of the documents past the stack of documents and the feed exit of the hopper, means urging the stack of documents toward the feed belt, stack hold-back means interposed between the feed belt and the stack of documents and normally in engagement with and maintaining the stack of documents in spaced relation from and out of engagement with the feed belt, power operated actuating means operable to disengage said documents from said stack hold-back means and engage the end document of the stack with the feed belt, and a fixed stop located on the other side of the document feed path in the feed exit of the hopper and spaced from the feed belt a distance approximately equal to the thickness of a document to form a frictional separator with the belt in the stack engaged feeding condition thereof, said stop being spaced from the stack hold-back means a distance slightly greater than the thickness of a document to form a throat block separator with the stack hold-back means in the stack engaged condition thereof.

12. A document feeder apparatus for feeding of documents stacked in a hopper through a feed exit of the hopper, comprising an accelerating medium in the hopper, stack hold-back means interposed between said accelerating medium and said stack of documents and normally engaging and maintaining said documents in spaced relation from and out of feeding engagement with said accelerating medium, actuating means operable to remove said documents from engagement with said stack holdback means for engagement with said accelerating medium to feed the end document of the stack through the feed exit of the hopper, means controlling said actuating means to return said stack of documents into engagement with said stack hold-back means when the leading edge of the end document has been fed past the feed exit of the hopper, and a variable gap separator including a fixed stop located in the feed exit of the hopper and successively providing for the documents adjacent the end document as the end document is fed from the stack through the feed exit of the hopper a narrow separation gap formed between the stop and the accelerating medium while in engagement with the end document being fed thereby and then a wide separation gap formed between the stop and the hold-back means when the leading edge of the aforesaid end document has been fed past the feed exit of the hopper.

13. A document feeding apparatus for demand feeding of documents stacked in a hopper out of the feed exit of the hopper, said apparatus comprising feeding means in the hopper operable in response to a command signal to engage the end document of the stack and feed it out through the feed exit of the hopper, a power driven drive roller assembly receiving the end document fed by said feeding means and continuing the feeding thereof to another destination, a narrow gap friction separator located in the feed exit of the hopper providing a frictional separating action on the documents adjacent the end document being fed from the stack by the feeding means, a wide gap throat separator in the same location of the feed exit of the hopper as said friction separator, and means disabling the frictional separating action provided by said narrow gap friction separator to permit the wide gap separating action of said wide gap throat sepa rator on the documents adjacent the end document being fed by the feeding means through the feed exit of the hopper when the aforesaid end document is being fed by the drive roller assembly.

References Cited in the file of this patent UNITED STATES PATENTS 856,346 Jahn June 11, 1907 2,093,654 Bellamy Sept. 21, 1937 2,856,187 Burckhardt et a1 Oct. 14, 1958 3,089,697 Brozo May 14, 1963 3,103,355 Hubbard et al Sept. 10, 1963

Claims

10. IN A DOCUMENT FEEDING APPARATUS FOR DEMAND FEEDING OF DOCUMENTS STACKED IN A HOPPER OUT OF THE FEED EXIT OF THE HOPPER AND INCLUDING DEMAND OPERATED FRICTION FEEDING MEANS IN THE HOPPER, MEANS URGING A STACK OF DOCUMENTS IN THE HOPPER TOWARD SAID FRICTION FEEDING MEANS, POWER DRIVEN DRIVE ROLLERS RECEIVING, A DOCUMENT FED BY SAID FRICTION FEEDING MEANS FOR CONTINUING THE FEEDING OF A DOCUMENT FED THERETO TO ANOTHER DESTINATION, A NARROW GAP FRICTION SEPARATOR LOCATED IN THE FEED EXIT OF THE HOPPER PROVIDING A FRICTIONAL SEPARATING ACTION ON A DOCUMENT FED ON DEMAND FROM THE STACK BY THE FRICTION FEEDING MEANS, A WIDE GAP THROAT SEPARATOR IN THE SAME LOCATION OF THE FEED EXIT OF THE HOPPER AS SAID FRICTION SEPARATOR, AND MEANS DISABLING THE FRICTIONAL SEPARATING ACTION PROVIDED BY SAID FRICTION SEPARATOR ON THE DOCUMENT FED TO THE POWER DRIVEN ROLLERS WHEN THAT DOCUMENT IS BEING FED BY THE DRIVE ROLLERS.