US3614090A

US3614090A - Document conveyor

Info

Publication number: US3614090A
Application number: US829608A
Authority: US
Inventors: George D Del Vecchio; Edward A Schwartz; Norman L Yarger
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1969-06-02
Filing date: 1969-06-02
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19
Also published as: DE2026063C3; GB1311766A; FR2049703A5; DE2026063B2; ES380271A1; NL7007787A; CH512751A; BE751308A; DE2026063A1; CA922330A; SE362150B

Abstract

A document conveyor assembly for moving a document past a work station. The assembly includes a drum for releasably supporting the leading edge of the document, drive means to rotate the drum so that at least a portion of the document is moved past the exposure slit and supplemental conveyor belts to continue the movement of the document past the exposure slit even though the conveyor drum is stopped. Programming means are also employed to cause a predetermined number of passages of the document past the work station prior to its release.

Description

United States Patent [72] inventors George D. Del Vecchio Briscoe Cove, North Rose; Edward A. Schwartz, Fairport, N.Y.;

Norman L. Yarger, Marengo, Ill.

[211 AppLNo. 829,608

[22] Filed June2,1969

[45] Patented Oct.19, 1971 [73] Assignee Xerox Corporation Rochester, N.Y.

[54] DOCUMENT CONVEYOR 1l Claims, 8 Drawing Figs. [52] U.S. Cl 271/51 [51] Int. Cl B65h 5/12 [50] Field of Search 5/ 4, 3;

[56] References Cited UNITED STATES PA TENTS 2,374,668 5/1945 Davidson 271/53 X 3,173,346 3/l965 Zemov et al 271/51 X Primary Examiner-Joseph Wegbreit Attorneys-Norman E. Schrader, James J. Ralabate and Michael J. Colitz, Jr.

ABSTRACT: A document conveyor assembly for moving a document past a work station. The assembly includes a drum for releasably supporting the leading edge of the document, drive means to rotate the drum so that at least a portion of the document is moved past the exposure slit and supplemental conveyor belts to continue the movement of the document past the exposure slit even though the conveyor drum is stopped. Programming means are also employed to cause a predetermined number of passages of the document past the work station prior to its release.

llO

PATENTEnuCr 19m?! 3.614.090

SHI-:Er 10F e INVENTORS GEORGE D. DEL VECCHIO EDWARD A.SCHWART`Z BY NORMAN L. YARGER A T TORNEV PATENTEUnm 19 Ism SHEET 2 0F 6 PATENEDuc 19 anl SHEET BUF 6 SIF FIG. 3

M1919 3,614,090 MENTE SHEEI SUF 6 PAIENTEunm 1s mn SHEET B UF 6 PROGRAMMER FIG. 8

DOCUMENT coNvEYoit This invention relates to document-conveying apparatus and in particular to apparatus for conveying a document past an image-projecting station of a reproducing machine.

More specifically, this invention relates to apparatus for holding a leading edge of a document on a drum and for moving it at a constant speed past an exposure station. Cooperable frictional conveyor belts continue to cause the flowing movement of the document past an exposure slit in an uninterrupted motion after the stopping of the document-supporting drum in a location whereat the leading edge of the document is in advance of the exposure slit for a subsequent pass of the document past the scanning slit.

In prior art reproducing machines various devices have been designed and constructed for supporting a document to be reproduced. In some devices, the document is held in a fixed position and the optical elements are moved with respect thereto. In other machines, the document is moved past a fixed exposure slit for flowingly projecting a light pattern of the document to a light receiving surface for creating a reproduction ofthe document.

In one of the prior art devices, as described for example in U.S. Pat. No. 3,239,220 issued in the name of L. C. Lot etal., the document is fed past the exposure slit in a flat orientation to project light images therefrom. If it is desired to initiate a subsequent imaging of the original, it is necessary to manually move the document output station to the document input station for a subsequent movement past the scanning slot. In another type of machine, as described for example in U.S. Pat. No. 3,100,112 issued in the name of H. C. Davis et al., the document to be reproduced is supported on a document drum which is rotated to move the document past a scanning slot one or a predetermined plurality of times prior to dispensing the document to a copy output station.

While both of these techniques are suitable for their purpose, neither provides for the rapid movement of an original document several times past an imaging slot with optimum efficiency.

The sheet feeding mechanism of the aforementioned Davis et al., patent is an efficient system but the size of the drum limits the size of document to be reproduced. That is, the document conveying apparatus of Davis et al., cannot accommodate a document of length longer than the circumference of the drum. If a longer document were supported by the Davis et al. drum, the trailing edge of the document would overlap its gripped leading edge so that a portion of the document adjacent the leading edge would be imaged on subsequent runs due to the fact that it would be optically marked by the trailing edge. Furthermore, if documents shorter than the circumference were supported on this type of drum, an inefficient system would be created since there would be an imaging of a portion of the circumference of the document drum which was not covered by the shorter documents.

It is, therefore, an object of the invention to improve document-handling apparatus whereby a document may be releasably secured in position on a rotating copy drum so as to be carried around thereby and so as to be readily releasable from the drum when desired.

Another object of this invention is to improve documenthandling apparatus by feeding a document of any length beneath a work station by the movement of a a first feed means and then continuing the movement of the trailing edge of the document by a second feed means even though the first feed means has stopped its movement.

Another object of the instant invention is to move the leading edge of a document to be reproduced by the rotation of a document supporting drum, stopping the copy drum in a position in advance of the exposure slit and continuing the movement of the trailing edge of the document past the exposure slit so that the entire movement of the document is fluid and uninterrupted.

A further object of the instant invention is to move documents of any length past a work station at a predetermined constant speed.

Another object of the instant invention is to move documents past an exposure station one or a plurality of times with a minimum of wasted time and motion of the document and feeding apparatus.

These and other objects of the instant invention are obtained by a document conveyor assembly for the moving of a document past an illuminated exposure slit at a constant speed. The conveyor assembly includes a drum for releasably supporting the leading edge of the document, means to rotate the drum so that at least a portion of the document is tlowingly moved past the exposure slit. The assembly also includes supplemental conveyor belts to continue the movement of the document past the exposure slit even though the conveyor drum is stopped. In this manner, the drum is in position for reconveying the document past the exposure slit after passage of the trailing edge of the document with minimum waste of time and movement of the document and feeding mechanisms.

For a better understanding of the invention as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings wherein:

FIG. l is a perspective view of a continuous and automatic xerographic reproducing machine employing apparatus constructed in accordance with the instant invention;

FIG. 2 is a schematic illustration of the apparatus shown in FIG. l;

FIG. 3 is an enlarged sectional view of the document feeder assembly with parts removed for clarity;

FIG. 4 is a perspective view of the document feeder drum and associated mechanisms with parts broken away to show internal construction;

FIG. 5 is a perspective view of the document drum and drive mechanisms as seen from the inboard side;

FIGS. 6 and 7 are sectional views of the document drum taken along lines 6-6 and 7-7 of FIG. 5; and

FIG. 8 is an electrical schematic of the control for the document feeding assembly.

Referring now to the drawings there is shown in the FIGS., a xerographic reproducing machine used for producing a xerographic reproduction from a moving original. The machine is adapted for continuous and automatic operation and includes a xerographic plate or surface 10 formed in the shape of a drum upon which the latent electrostatic representation of the document is created. The plate has a photoconductive layer of light-receiving surface on a conductive backing joumaled in a frame to rotate in the direction indicated by the arrow. The rotation will cause the plate surface to sequentially pass a series of xerographic processing stations. For the purpose of the present disclosure, the several xerographic processing stations in the path of movement of the plate surface may be described functionally as follows:

A charging station A, at which a uniform electrostatic charge is deposited on the photoconductive plate;

An exposure station B at which light or radiation patterns or copy to be reproduced is projected onto the plate surface to dissipate the charge in the exposed areas thereof to thereby form a latent electrostatic image of the copy to be reproduced;

A developing station C at which the xerographic developing material, including toner particles having an electrostatic charge opposite to that of the latent electrostatic image, is cascaded over the plate surface whereby the toner particles adhere to the latent electrostatic image to form a toner image in a configuration ofthe copy being reproduced;

A transfer station D at which the toner image is electrostatically transferred from the plate surface to a transfer material or support surface; and

A drum cleaning and discharge station E at which the plate surface is brushed to remove residual toner particles remaining thereon after image transfer and exposed to a relatively bright light source to effect substantially complete discharge of any residual electrostatic charge remaining thereon.

It is felt that the preceding description of the xerographic processing stations is sufficient for an understanding of the instant invention. Further details of the xerographic apparatus may be had by reference to U.S. Pat. No. 3,301,126 issued to Robert F. Osborne et al.

In addition to the above described apparatus disclosed in the aforementioned Osborne et al. patent, the xerographic machine may be provided with an optical assembly 12 of the type disclosed in copending application Ser. No. 829,605 filed concurrently herewith in the name of George D. Delvecchio et al. The optical assembly l2 is variable to permit a plurality of optical reductions. When these reductions are employed, the speed of movement of the document handling apparatus is varied proportionately to retain an undistorted projection of the document onto the xerographic surface at the reduced rate. In addition thereto, the copy sheet support material is retained at a support station 14 for being fed through the reproducing machine and for being discharged therefrom with the fused copy at either of two

copy catch trays

16 or 18. A sheet folding and turning station 20 is provided along the sheet feed path whereby the sheet material directed to the smaller of the copy catch trays 16 may be advanced in either a folded or unfolded state. Details of the elements along the sheet feed path may be had by reference to copending application Ser. No. 829,365 filed concurrently herewith in the name of George D. DelVecchio et al.,

The leading edge of the document to be reproduced is supported on a document feed drum 24 supported on concentric support shaft 26 for concurrent rotation therewith. The ends of the support shaft 26 are journaled in side frame portions 28 of the machine. One end of the main drive shaft includes a gear 32 for imparting power thereto through a gear train assembly 34 as shown in FIG. 5. Also associated with the support shaft 26 is an electric clutch-brake assembly 36 for stopping and starting the rotation of the drum in a predetermined fashion during the constant rotation of the gear train assembly 34.

The drum assembly includes a plurality of protruding gripper fingers 38 extending across the face of the drum 24 for gripping the leading edge of the document to be reproduced. Each gripper finger 38 has an internal portion 40 within the drum secured within support blocks 42 which also contain an actuator rod 44 displaced from the main support shaft 26 of the dmm assembly. A coil spring 46 is provided for each gripper finger 38 and is mounted within a cylindrical cavity 48 within the bearing support blocks 42 and in contact with a pin 50 extending transverse through the internal portion 40 of the gripper finger 38. This coil spring 46 tends to urge the pin away from the surface of the drum and consequently the gripper fingers into engagement with the surface of the drum for supporting a document.

The lowermost portion of the internal portion 40 of the gripper fingers 38 is in coacting relationship with flat portions of the actuator rod 44 so that movement of the actuator rod in a clockwise direction as viewed in FIG. 6 will urge the gripper fingers away from the surface of the drum against the action of spring 46 to pennit loading or unloading of a document from the drum. This orientation of the actuator rod is shown in FIG. 4. Rotation of the actuator rod in the counterclockwise direction as viewed in FIG. 7 permits the coil spring 46 to urge the gripper fingers 38 into contact with the surface of the drum to permit the gripping of a document.

The actuator rod may be rotated to disengage the gripper fingers by a manual mode or an automatic mode. In order to raise the gripper fingers through the manual mode, a knurled cap 52 is provided on the left hand side of the document drum as viewed in FIG. l. This knob, as also seen in FIGS. S and 7 is mounted concentric with the document drum 24 on support shaft 26. The support shaft 26 extends through the cap. This knurled cap is accessible to the operator through the document input slot 54 adjacent the operators station shown in FIG. l.

The end of the actuator rod 44 adjacent the knurled cap 52 is secured to a collar 56 fixedly mounted with respect to the rod. The collar 56 is provided with an upstanding stud 58 which is in turn mounted to a coil spring 60. The other end of the coil spring is mounted on a stud 62 upstanding from a face plate 64 of the document drum 24. In this manner, the coil spring 60 tends to urge the collar 56 and consequently the actuator rod 44 in a counterclockwise direction as viewed in FIG. 7 to permit the gripper fingers 38 to be maintained in a closed orientation. Since the

studs

58 and 62, spring 60, collar 56 and actuator rod 44 are mounted for rotation with the document drum 24, the force provided by the coil spring 60 renders these elements uneffected by rotation of the drum 24.

Also mounted on the collar 56 is a second stud 66 urged by spring 60 into contact with cam surface 68 formed into the inner surface of the knurled cap 52. The cam surface 68 is shaped so that rotation of the cap 52 in a counterclockwise direction as viewed in FIG. 7 will move the stud 66 in a clockwise direction to rotate the collar 56 and actuator rod 44 in a clockwise direction against the urging of the spring 60. With this movement of the knurled cap 52, the actuator rod 44 can urge the gripper fingers 38 upwardly to release a document held thereby. Release of the knurled cap 52 permits the spring 60 to counter rotate collar 56, actuator rod 44 and cap 52 to close the gripper fingers 38. This mode of releasing the gripper fingers is operable at any position of rotation of the document drum whether or not power is supplied to the machine.

Rotating of the actuator rod 44 for releasing the gripper fingers 38 is also operable in an automatic mode. As most clearly seen in FIG. 4, the mechanisms for automatically operating the gripper fingers includes a cam follower 70 fixedly mounted with respect to the end of the actuator rod 44 remote from the knurled knob 52.

This cam follower 70 is oriented so that it may interact with a cam surface of a pivotal main cam plate 72 and the cam surface of a pivotal auxiliary cam plate 74 between less than a 200 feed position, or 7 oclock and beyond the 340 load position, about Il oclock, as viewed in FIGS. 2, 3 and 4. When the main cam plate 72 is moved from interference relationship with the cam follower 70, the cam follower 70 is uneffected thereby during drum rotation and the gripper fingers 38 remain closed.

The main cam plate 72 is secured for pivotal motion with respect to the drum 24 and drum support shaft 26 by a short shaft journaled within the side frames 28 of the machine. Pivotal motion is imparted to the torque shaft 76 and main cam plate 72 by means of a clevis 80 supported in the piston 82, of an air cylinder 84 which rocks the cam plate 72 into and out of an operative relationship position with respect to the cam follower 70 in a programmed fashion to be later described.

Also, supported adjacent this end of the document feed drum 24 is the auxiliary cam plate 74 mounted for rotation on short shaft 86 which is likewise fixedly mounted with respect to the frames 28 of the machine. Intermediate lever arm 88 with

pivotal studs

90 and 92 interconnects the auxiliary cam plate 74 with the main cam plate 72. Consequently, when the air cylinder pivots the main cam plate out of operative relation with the cam follower 70 as shown in FIG. 7, shaft 90 moves in a arcuate path to move shaft 92 and consequently pivot the cam surface end of the supplemental cam plate 74 upwardly about shaft 86, out of operative position with respect to the cam follower 70. When the cylinder 84 is activated to push the main cam plate 72 into operative relationship with respect to the cam follower 70, the supplemental cam plate 74 pivots downwardly into operative association with the cam follower 70 as shown in FIG. 4. When in the operative position, the

cam surface may act to permit the pivoting of the cam follower 70 in a counterclockwise direction as viewed in FIG. 4 to urge the gripper fingers 38 away from the drum 24 and thereby permit the release of a held document.

The air cylinder 84 for moving the cams into operative relationship with the cam follower can be actuated in either of two manners. The first includes the depression of the GRIPPER button 94 adjacent the operators station. This will reverse the valve V-1 to drive air into the other side of the cylinder to move the piston to its alternate position by the flow of air from a suitable source of pressurized air not shown. This action, however, can only be achieved when the cam follower is between the 7 and 11 oclock positions. This is because the positioning of the cam follower 70 at another orientation will not cause the contact between the cam 72 and 74 and cam follower 70. The air cylinder may also be operated in an automatic mode correlated through the general programming of the machine in a manner to be described. v

ln the normal operation of the document feed drum, the drum is rotated from its load position near ll oclock as viewed in FIGS. 2 and 3 upon depression of the START PRINT button 96 to move the document past the scanning slot 13 through its movement by the main drive shaft 98 ofthe gear train assembly 34. The lamps LMPS are not illuminated at this time. The drum is then stopped when the gripper fingers and cam follower have reached the feed position near 8 0- clock. ln this position, the'drum is incapable by itself to transport the trailing edge of a long document past the exposure station. To effect this result, supplemental drivebelts 100 are provided adjacent the lower right quadrant of the document feeding drum 24 as viewed in FIGS. 2 and 3. These drivebelts 100 are adapted to make frictional contact with the exterior of the drum and document supported thereby, even after the leading edge of the document has moved to the load position and has stopped. The drivebelts are mounted for movement in a continuing path of movement by driven roller 102 and

idler rollers

104, 106, 108 and 110. Idler roller 108 is spring tensioned by spring means 112 to maintain these drivebelts in tension and in driving engagement with driven roller 102 and the surface of the document feed drum 24. The belts are adapted to be driven through gear 114 supported on shaft 116 supporting roller 102. Gear 114 mates with the main drive shaft so that the belts 100 and drum 24 move at the same linear speed. Consequently, these belts function to drive trailing edge of the document past the exposure slit 13 at a constant speed even though the document drum has been stopped.

It has been found desirable to employ an overrunning clutch in the clutch-brake assembly 36 and to gear

shafts

26 and 116 so that the document drum has a slightly slower surface speed than the belts 100. In this manner the power through shaft 26 and the clutch brake assembly 36 will give a starting impulse to drum 24 but continued drum movement, from imaging slot 13 to its stopped 8 oclock position is effected by frictional force from belts 100 overrunning the clutch. By this arrangement, no variation of document speed occurs as the drum is stopped and the belts begin moving the document.

When the trailing edge of the document approaches the exposure slit 13, a loop formed of the document will be forming down the vertical face of feed belts 100. At this time the machine programming will restart the drum to feed the leading edge of the document beneath the exposure slit 13 with the lamps illuminated to flowingly project light images on the drum 10. The leading edge will again stop at the feed position with the belts 100 causing the continued smooth motion of the rest of the document as described above. This sequence continues until the programming determines that the last imaging of the document is occuring. At this time the air cylinder is activated to drive in cams 72 and 74 so that movement of the leading edge to the feed position will cause the opening of the grippers 38 by the rotation of cam 70 to drop the document down belts 100 toward the document catch tray 142.

Positioned behind the document feed belts 100 beneath the document feed drum 24 is plenum chamber 118 adapted to be connected to a suitable source of vacuum to assist in controlling a loop in the document which is normally formed when the leading edge of the document is held in the 8 oclock position while the trailing edge is moved past the exposure slit 13. A flexible document subcarrier 101, as shown in FIGS. 3 and 5 may also be employed as further assurance that the document is held smooth during imaging and to assist in assuring the document is released from the drum after its last imaging. A flexible material such as mylar'effects these results.

When plural passes of a long document are to be made, the trailing edge of the document will be dropped from its contact between the document drum 24 and feed belts 100. With this arrangement, the leading edge of the document is ina positionv adjacent the exposure slit for subsequent passes past the imaging slot immediately upon the passing of the trailing edge of the document therefrom.

In order to operate the machine of the instant invention an operator at front of the machine, positions the leading edge of the document under the gripper fingers 38. Tray 144 assists in supporting the document at this time. The opening of the gripper fingers is caused by the depression of the GRIPPER" button 94 adjacent the operator station. A second depression of this button causes the closing of the gripper fingers. This opening and closing of the gripper fingers is effected through the driving of the air cylinder in and out with the cam follower 70 in the ll oclock position. In the alternative, the gripper fingers could be manually opened by the twisting of the knurled knob 52 on the opposite side of the document feed drum 24.

Before or after positioning the document, the operator may select the magnification desired by pressing the appropriate size reduction button on the console 95. The pressing of one of these buttons will act to properly position the optical assembly to the appropriate optical reduction. In association therewith, the transmission 146 of the gear train-assembly 34 will also become oriented to drive the document feed drum 24 and belts to drive the document being reproduced at a speed correlated with that of the optical reduction chosen.

The operator will also dial in the copy count desired on the copy count dials 148 and 150 to thereby cause the appropriate number of imaging passes of the document and consequently the appropriate number of documents to be reproduced from the same original.

The depression of the START-PRINT button 96 will then activate the main drive mechanism of the machine to tum the xerographic surface l0 through the various xerographic processing stations, feed the copy sheet through the reproducing machine to one of the copy catch trays and, concurrently therewith, activate the main drive for the document feeding assembly. This motion is imparted through the three speed transmission 146 to drive the main document feed roll and associated feeding mechanisms in the manner described above.

The document drum will then rotate to stop at the load position by the programmed actuation of the clutch-brake assembly 36 whereupon the trailing edge of the document will be slid across the fixed document feed drum 24 by the action of the supplemental belts 100. The cams 72 and 74 will be out of engagement with the cam 70 as long as subsequent images are to be projected to the xerographic surface as determined by the number of copies dialed into the programmer. After the leading edge of the document has passed the scanning slit for the projection of the last image from the document drum, the air cylinder 84 will be actuated to drive in the cam plates 72 and 74 so that movement of the drum and cam follower to the load position will cause the pivoting motion of the actuator rod to open the gripper fingers 38 and release the document being reproduced.

The document feeder as described herein is adapted to handle copy of a wide variety of sizes. When adapted for use in copying engineering drawings, the document feeder would be equipped with a document drum at least 22 inches long to handle D size drawings which are 22x34 inches. The C size drawings of 17x22 inches could also be handled. But these two size documents would require optical reductions when the machine is adapted to copy onto B size copy sheets of l lXI7 inches or A size copy sheets of 8%Xll inches. A and B size documents could be reproduced at a 1:1 optical magnification or at a reduced rate.

In a preferred mode of operation, the document drum would be driven continually during operation through the three speed transmission 146. When the l() percent optical reduction mode is employed, the document drum would be rotated at the same surface speed as that of the photoreceptive surface 10. When the 50 percent reduction mode is employed, the document drum would rotate at twice the surface speed as the photoconductive surface while the 65 percent reduction mode would require an intermediate speed. These speeds are attained through the three speed transmission operatively coupled with the main machine programming to effect the proper speed and imaging correlation.

As described hereinabove, the power output from the transmission is employed to rotate the drum in the clockwise direction as viewed in FIGS. 2 and 3 through the clutch-brake assembly 32. The clutch-brake assembly is a commercially available two-detent assembly adapted to be locked at two preset positions and released by the pulsing of a solenoid SOL-l operatively coupled thereto. Clutch-brake assemblies adapted for this purpose are commercially available. The instant clutch is preset to stop in the load position at about l l oclock as viewed in FIGS. 2 and 3 and the feed position of 7 oclock as also viewed in these figures. Also operatively coupled with the drum controls are limit switches LS-26 and LS-27 operable o` of cams 126 and 127 rotatablewith the document drum. The cams are positioned to open the switches so that LS-27 is opened when the drum is in the 2 oclock positionas seen in FIGS. 2-4 and LS-26 is opened when the gripper fingers are in the feed position.

When one of the

optical reduction buttons

150, 152 or 154 is depressed, the optical reduction logic determines which of the three cycle switches CS-9, CS-l0 or CS-ll will become adapted to be closed during operation. These cycle switches are operated off the main machine cam bank as disclosed in the aforementioned Osborne et al. patent and one of which, as determined by the state of the optical reduction buttons, will be closed periodically, as for example every 1 yseconds, when the xerographic drum rotates at 6.67 inches/second. The closing of one of these cycle switches will determine the starting time of the leading edge of the document from the feed position. These various starting times are required since the various speeds of rotation of the document drum would otherwise cause the imaging of the leading edge at various sections of the xerographic drum. This in turn would cause improper registration of the copy sheet with the toner image.

With one of the cycle switches closed, e.g., CS-ll coupled to the 100 percent button, power will be imparted through the startup logic to energize relay K45 which will be held in through holding contact K45-1. The A button 160 will also be depressed to forward smaller copy sheets. The energization of relay K45 will also close contact K45-2 to energize the clutch solenoid SOL-1 which withdraws the actuator arm of the clutch-brake assembly and permits the driving of the document drum. As the leading edge of the document moves past the optical exposure slot, cam member 127 will trip LS-27 to open the line to holding contact to K45-1 causing the deenergization of relay K45, the opening of contact K45-2 and the deenergization of solenoid SOL-. This returns the actuator arm into interference position to cause the stoppage of the document dmm when the leading edge reaches the feed position. This cycle will be continually repeated as the main cam bank recloscs the appropriate cycle switch to reinitiate the cycle.

This procedure is similar to that effected when the lead edge is moved from the load position to the feed position with the lamps not illuminated and prior to the first imaging. During this movement, however, cam 126 is not holding LS-26 open as it would if the leading edge were being moved from the feed position. The startup logic interprets this difference as part of the logic to distinguish between movement of the document from the feed and load positions.

As the leading edge of the document moves away from the feed position to image the last copy as dialed in on the programmer, the last cycle logic will be energized from the programmer to pneumatically reverse air cylinder 84 to drive the cams into interference position after the start-of-scan of the leading edge. Thus the movement of the leading edge of the held sheet toward the feed position will bring cam follower 70 into contact with the cams 71 and 74 to open the gripper fingers and drop the leading edge of the document toward the copy catch tray. After a short time delay as determined by the last cycle logic, the gripper fingers will be rotated to the load position while causing an opening in the line to holding contact K45-1 to thereby prevent the continued energization of X45 and the bypassing of the clutch past the load position.

The same program cycle is employed when B size copy sheets are being fed through depressing B button 162 except that normally closed contact k4l-l will periodically be opened and closed off of a binary counter operatively coupled with the machine programming so that the appropriate cycle switch CS-9 or (IS-10 or CS-ll will only be closed for every other pulse applied to it by the main cam bank. ln this manner larger documents will only leave the feed position for every other closing of switches CS-9 or CS-10. This will permit the larger documents to be fed past the exposure slot without the leading edge thereof moving beneath its training edge.

As can be understood from the foregoing description the document handling apparatus of the instant invention is adapted for a single or multiple passes of' documents to be imaged of virtually any length since the motion of the trailing edge passed the imaging slot is effected by the supplemental belts in association therewith. Furthermore, the stopping of the gripper finger in advance ofthe imaging slot while the continued imaging of the document occurs, permits the leading edge of the document to be in proper position for being quickly recycled beneath the exposure slot for supplemental passes of the document therepassed.

While the instant invention as to its objects and advantages have been described as being carried out in a single embodiment thereof. It is not intended to be limited thereby but it is desired to be covered broadly within the scope of the appended claims.

What is claimed is:

l. A sheet conveying assembly including first sheet feed means positioned adjacent work station,

means on said first sheet feed means to support the leading edge of the sheet to be conveyed thereby,

means to move said first sheet feed means whereby the supported sheet is conveyed past the work station and stopped at a predetermined point therepast and,

second sheet feed means in association with said first sheet feed means to effect the movement of the trailing edge of the fed sheet past the work station after the stoppage of said first sheet feed means. 2. The sheet conveying assembly as set forth in claim l wherein said first sheet feed means is cylindrical and wherein said second sheet feed means is an endless conveyor in operative association with said first sheet feed means to frictionally contacta sheet supported thereon and slide it, relative to said first sheet feed means after said first sheet feed means is stopped.

3. Conveying apparatus adapted to move a document past a work station including l a document drum positioned adjacent the work station, gripper means on the document drum to support the leading edge of the document to be moved past the work station,

means to rotate said document drum so that the gripper means move a supported document past the work station,

means to stop the movement of said document drum with said gripper means in advance of the work station and supplemental sheet feed means in contact with the document supported on said drum to convey the trailing edge of the supported document past the exposure slot by sliding it on said document drum after said document drum is stopped.

4. The apparatus as set forth in claim 3 and further including means to reactivate said means to rotate said document drum after the passage of the trailing edge of the document past the work station.

5. The apparatus as set forth in claim 4 and further including means to release the document from said gripper means after the leading edge of the document has been moved past the work station a predetermined number of times.

6. A document conveyor assembly including a document support means positioned adjacent a work station,

gripper means on said document support means to hold the leading edge of the document to be conveyed past the work station, first drive means to move said document support means from a load position whereat said gripper means are in advance of the work station to a feed position reached by the passage of the gripper means past the work station,

means to initiate said first drive means for the movement of said document support means from the load position to the feed position and to stop such movement upon the reaching of said feed station,

supplemental document feed means in contact with said document support means,

and second drive means to activate said supplemental drive means during the movement of said document support means and to continue such driving after the termination of movement ofsaid document support means.

7. The apparatus as set forth in claim 6 wherein said first and second drive means are operatively coupled and further including selectively actuated clutch means in association with said document support means and said first drive means to terminate the motion of said document support means independent of termination of the movement of said supplemental document feed means.

8. Sheet-conveying apparatus including first sheet feed means capable of supporting and moving a sheet past a work station,

first drive means to move said first sheet feed means,

second sheet feed means positioned adjacent said first sheet feed means to permit the movement of sheet material therebetween,

second drive means to move said second sheet feed means,

means coupling said first drive means and said second drive means to cause concurrent movement between said first and second sheet feed means and clutch means operatively interconnecting said first drive means and said first sheet feed means to permit the inactivation of said first sheet feed means independent of the activation of said second sheet feed means.

9. A document conveying assembly for use in a reproducing machine of the type wherein a document is scanned as it flowingly passes an exposure slot including a document support drum,

gripper means on said document support drum to retain the leading edge of a document on said document support drum,

selectively operable means to open and close said gripper means to accept or release a document,

first drive means to rotate said document support drum such that the gripper fingers are moved past the exposure slot to feed position in advance of said exposure slot, means to stop the movement of said document support drum when said gripper fingers reach the feed position,

supplemental conveyor means in contact with said document support drums that a fed document is passed therebetween as it moves past the exposure slot to the feed position and second drive means to move said supplemental conveyor means, said second drive means and said first drive means being operatively coupled such that the stopping of said document support drum at the feed position will not necessarily stop the movement of said supplemental drive means.

10. The assembly as set forth in claim 9 wherein said second drive means is driven off of said first drive means and further including a selectively engageable clutch means between said first drive means and said sup prt drum to permit the inactivation of said support drum w ile said supplemental conveyor means feeds the trailing edge of the fed document past the exposure slot.

1 1. The assembly as set forth in claim l0 and further including means to control said clutch to stop said document feed drum at said feed position for each exposure of the document.

Claims

1. A sheet conveying assembly including first sheet feed means positioned adjacent work station, means on said first sheet feed means to support the leading edge of the sheet to be conveyed thereby, means to move said first sheet feed means whereby the supported sheet is conveyed past the work station and stopped at a predetermined point therepast and, second sheet feed means in association with said first sheet feed means to effect the movement of the trailing edge of the fed sheet past the work station after the stoppage of said first sheet feed means.

2. The sheet conveying assembly as set forth in claim 1 wherein said first sheet feed means is cylindrical and wherein said second sheet feed means is an endless conveyor in operative association with said first sheet feed means to frictionally contact a sheet supported thereon and slide it, relative to said first sheet feed means after said first sheet feed means is stopped.

3. Conveying apparatus adapted to move a document past a work station including a document drum positioned adjacent the work station, gripper means on the document drum to support the leading edge of the document to be moved past the work station, means to rotate said document drum so that the gripper means move a supported document past the work station, means to stop the movement of said document drum with said gripper means in advance of the work station and supplemental sheet feed means in contact with the document supported on said drum to convey the trailing edge of the supported document past the exposure slot by sliding it on said document drum after said document drum is stopped.

6. A document conveyor assembly including a document support means positioned adjacent a work station, gripper means on said document support means to hold the leading edge of the document to be conveyed past the work station, first drive means to move said document support means from a load position whereat said gripper means are in advance of the work station to a feed position reached by the passage of the gripper means past the work station, means to initiate said first drive means for the movement of said document support means from the load position to the feed position and to stop such movement upon the reaching Of said feed station, supplemental document feed means in contact with said document support means, and second drive means to activate said supplemental drive means during the movement of said document support means and to continue such driving after the termination of movement of said document support means.

8. Sheet-conveying apparatus including first sheet feed means capable of supporting and moving a sheet past a work station, first drive means to move said first sheet feed means, second sheet feed means positioned adjacent said first sheet feed means to permit the movement of sheet material therebetween, second drive means to move said second sheet feed means, means coupling said first drive means and said second drive means to cause concurrent movement between said first and second sheet feed means and clutch means operatively interconnecting said first drive means and said first sheet feed means to permit the inactivation of said first sheet feed means independent of the activation of said second sheet feed means.

9. A document conveying assembly for use in a reproducing machine of the type wherein a document is scanned as it flowingly passes an exposure slot including a document support drum, gripper means on said document support drum to retain the leading edge of a document on said document support drum, selectively operable means to open and close said gripper means to accept or release a document, first drive means to rotate said document support drum such that the gripper fingers are moved past the exposure slot to feed position in advance of said exposure slot, means to stop the movement of said document support drum when said gripper fingers reach the feed position, supplemental conveyor means in contact with said document support drums that a fed document is passed therebetween as it moves past the exposure slot to the feed position and second drive means to move said supplemental conveyor means, said second drive means and said first drive means being operatively coupled such that the stopping of said document support drum at the feed position will not necessarily stop the movement of said supplemental drive means.

10. The assembly as set forth in claim 9 wherein said second drive means is driven off of said first drive means and further including a selectively engageable clutch means between said first drive means and said support drum to permit the inactivation of said support drum while said supplemental conveyor means feeds the trailing edge of the fed document past the exposure slot.

11. The assembly as set forth in claim 10 and further including means to control said clutch to stop said document feed drum at said feed position for each exposure of the document.