US3281145A

US3281145A - Paper reject mechanism

Info

Publication number: US3281145A
Application number: US332461A
Authority: US
Inventors: Richard F Reilly
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1963-12-23
Filing date: 1963-12-23
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25

Description

R. F. REILLY Oct. 25, 1966 PAPER REJECT MECHANISM l0 Sheets-Sheet 1 Filed Dec. 23, 1963 INVENTOR. RICHARD F. RElLLY A TTORNE V Oct. 25, 1966 R. F. REILLY PAPER REJECT MECHANISM 1O Sheets-Sheet 2 Filed Dec. 23, 1963 INVENTOR. RICHARD F. REILLY BY% q M A T TORNE V Oct. 25, 1966 R. F. REILLY PAPER REJECT MECHANISM Filed Dec. 23, 1963 10 Sheets-Sheet 3 INVENTOR. RICHARD F. REILLY A T TORNE Y Oct. 25, 1966 R. F. REILLY PAPER REJECT MECHANISM l0 Sheets-Sheet &

Filed Dec. 23, 1963 INVENTOR. RICHARD F. REILLY A T TORNEY R. F. REILLY Oct. 25, 1966 PAPER REJECT MECHANISM l0 Sheets-Sheet 5 Filed Dec. 25, 1963 INVENTOR. RICHARD F. REILLY BY A TTORNEY Oct. 25, 1966' R. F. REILLY 3,281,145

PAPER REJEGT MECHANISM Filed Dec. 23, 1963 10 Sheets-Sheet 6 INVENTOR. RICHARD F. REILLY A T TORNEV Oct. 25, 1966 R. F. REILLY PAPER REJECT MECHANISM l0 Sheets-Sheet 7 Filed Dec. 23, 1963 INVENTOR RICHARD F. REILLY BY MW W ATTORNEY Oct. 25, 1966 Filed Dec. 23, 1963 R. F. REILLY 1Q Sheets-Sheet 8 IOLS @@ 72s ""UIIH g5 D f EELS m 725 j q l, x 5;;

i 7/2 -7/3 5 i I 722 /-j 5* j I INVENTOR. RICHARD F. REILLY A T TORNE Y Oct. 25, 1966 Filed Dec. 23, 1963 R. F. REILLY PAPER REJECT MECHANISM 10 Sheets-Sheet 9 FIG.

RICHARD F. REILLY BY II(( %/%W A T IORNE Y Oct. 25, 1966 Filed Dec. 23, 1963 PAPER REJEGT MECHANISM R. F. REILLY 10 Sheets-Sheet l0 A T TOR/YE V .of the drum surface United States Patent 3,281,145 PAPER REJECT MECHANISM Richard F. Reilly, Webster, N.Y., assignor to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Dec. 23, 1963, Ser. No. 332,461 2 Claims. (Cl. 271-57) This invention relates in general to a sheet feed mech anism and, in particular, to a paper reject mechanism.

More specifically, the invention relates to an improved paper reject mechanism for diverting superposed sheets from the normal path of sheet delivery.

In an automatic xeromatic apparatus adapted to effect reproductions onto cut sheet material, it is necessary to feed sheets one at a time to the xerographic plate in proper registration with the powder image formed on the xerographic plate whereby the powder image is transferred to the sheet material. In such an apparatus, the advancement of superposed sheets to the xerographic drum is not desired.

It is, therefore, the principal object of this invention to improve sheet reject mechanisms for diverting superposed sheets from the normal path of sheet delivery.

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. 1 illustrates schematically a preferred embodiment of a xerographic apparatus having a sheet feed mechanism with a paper reject mechanism constructed in accordance with the invention;

FIG. 2 is a front view of a portion of the paper transport mechanism;

FIG. 3 is -a view similar to FIG. 2 with parts broken away to show the elements of the transport mechanism including the paper reject mechanism and the paper registering mechanism;

FIG. 4 is a top view of a portion of the paper transport mechanism to the right of the xerographic drum;

FIG. 5 is a sectional view showing the paper registration stops and feed rollers of the paper transport;

FIG. 6 is an enlarged front view of the double sheet sensing device of the paper transport;

FIG. 7 is a right-hand view of the double sheet sensing device;

FIG. 8 is an enlarged view with parts broken away of the sheet reject mechanism and the sheet registration mechanism of the paper transport assembly;

FIG. 9 is a rear view of the paper reject mechanism and the sheet registration mechanism of the paper transport assembly;

FIG. 10 is a top view of a transport drive assembly and a switch actuator mechanism;

FIGS. 11 and 12 are a schematic electrical wiring diagram of the electrical components of the xerographic apparatus.

As shown schematically in FIG. 1, the automatic xerographic reproducing appartus comprises a xerographic plate including a photoconductive layer or light-receiving surface on a conductive backing and formed in the shape of a drum, which is mounted on a shaft journa'led in a frame to rotate in the direction indicated by the arrow to cause the drum surface sequentially to pass a plurality of xerographic processing stations.

For the purpose of the present disclosure, the several xerographic processing stations in the path of movement may be described functionally, as follows:

A charging station, at which a uniform electrostatic charge is deposited on the photooonductive layer of the xerographic drum;

An exposure station, at which a light or radiation pattern of copy to be reproduced is projected onto the drum surface to dissipate the drum charge in the exposed areas thereof and thereby form -a latent electrostatic image of the copy to be reproduced;

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

A transfer station, at which the xerographic powder image is electrostatioally transferred from the drum surface to a transfer material or a support surface; and,

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

The charging station is preferably located, as indicated by reference character A. As shown, the charging arrangement includes a corona charging device 21 which includes a corona discharge array on one or more corona discharge electrodes that extend transversely across the drum surface and are energized from a high potential source and are substantially closed within a shielding member.

Next subsequent thereto in the path of motion of the xerographic drum is an exposure station B. An optical scanning or projection system is provided to project a flowing image onto the surface of the photoconductive drum from a stationary original.

The optical scanning or projection assembly comprises a stationary copyboard which consists of a transparent curved platen member 22 such as, for example, a glass plate or the like positioned on the exterior of the cabinet, which is adapted to support a document to be reproduced, the document being uniformly illuminated and arranged in light projecting relation to the moving light-receiving surface of the xerographic drum. Uniform lighting is provided by banks of lamps LMPS arranged on opposite sides of the copyboard. Scanning of the document on the stationary copyboard is accomplished by means of a mirror assembly which is oscillated relative-to the copyboard in timed relation to the movement of the xerographic drum.

The mirror assembly, which includes an object mirror 23 is mounted below the copyholder to reflect an image of the document through a lens 24 onto an image mirror 25 which in turn reflects the image onto the xerographic drum through a slot in a fixed light shield 26 positioned adjacent to the xerographic dmm surface.

Adjacent to the exposure station is a developing station C in which there is positioned a developer apparatus 30 including a casing or housing having a lower or sump portion for accumulating developer material. A bucket type conveyor is used to carry the developing material to the upper part of the developer housing where it is cascaded over a hopper chute onto the xerographic drum to effect development. A toner dispenser is used to ac curately meter toner to the developing material as toner particles are consumed during the developing operation.

Positioned next and adjacent to the developing station is the image transfer station D which includes a sheet feeding arrangement adapted to feed sheets of support material, such as paper or the like successively to the xerographic drum in coordination with the presentation of the 'support material and the rotating drum. the electrostatic field created by the corona transfer developed image on the drum surface at the transfer station.

The sheet feeding mechanism includes a sheet feed device 40 adapted by means of vacuum feeders to feed the top sheet, of a stack of sheets on a tray 41, to a set of feed rollers 42 for advancement by the feed rollers of the sheet to a paper transport 4 which, in turn, conveys the sheet to a sheet registration device 45 positioned adjacent to the xerographic drum. The sheet registration device arrests and aligns each individual sheet of material and then in timed relation to the movement of the xerographic drum, advances the sheet material into contact with the xerographic drum in registration with a previously formed xerographic powder image on the drum.

The transfer of the xerographic powder image from the drum surface to the sheets of support material is effected by means of a corona transfer device 51 that is located at/ or immediately after the line of contact between the In operation,

device is effective to tack the support material electrostatically to the drum surface, whereby the support material moves synchronously with the drum while in contact therewith. Simultaneously with the tacking action, the electrostatic field is effective to attract the toner particles comprising the xerographic powder image from the drum surface and cause them to adhere electrostatically to the surface of the support material.

Immediate subsequent to the image transfer station, there is positioned a stripping apparatus or paper pickoif mechanism 52 for removing the sheets of support material from the drum surface. This device, which is of the type disclosed in Rutkus et al. Patent 3,062,536, includes a plurality of small diameter orifices supplied with pressurized aeriform fluid by a suitable pulsator or other device. The pulsator is adapted to force jets of pressurized aeriform fluid through the outlet orifices into contact with the surface of the xerographic drum slightly in advance of the sheet of support material to strip the leading edge of the sheet from the drum surface and to direct it onto an endless conveyor 55 whereby the sheet material is carried to a fixing device 60. At the fixing device, the transferred xerographic powder image on the sheet of support material is permanently fixed or fused thereto as by heat. After fusing, the finished copy is discharged from the apparatus at a suitable point for collection externally of the apparatus by means of the conveyor 65.

The next and final station in the device is a drum cleaning station E, having positioned therein a corona pre- -clean device 66, similar to corona charging device 21, a drum cleaning device 70 adapted to remove any powder remaining on the xerographic drum after transfer by means of a rotating brush 71, and a discharge lamp LMP- 1 adapted to flood the xerographic drum with light to cause dissipation of any residual electrical charge remain 'ing on the xerographic drum.

To remove residual powder from. the xerographic drum, there is disposed a cylindrical brush 71, rotatably mounted on an axle and driven by a motor, not shown. For collecting powder particles removed from the xerographic drum by the brush, there is provided a dust hood 73 that is formed to encompass approximately two-thirds of the brush area. To ensure thorough cleaning of the brush, a flicking bar 74 is secured to the interior of the dust hood adjacent the edge of the outlet duct 75 of the dust hood and in interfering relation with the ends of the brush bristles whereby dust particles may be dislodged therefrom.

' For removing dust particles from the brush and dust hood, an exhaust duct 76 is arranged to cover the outlet of the dust hood, the exhaust duct being connected at its other end to the wall of a filter box 77 attached to the duct hood. A filter bag 78 is secured Within the filter box, with the mouth of the filter bag in communication with the exhaust duct. A motor fan unit MOT6 connected to the filter box, produces a flow of air through the filter box drawing air through the area surrounding the xerographic drum and the dust hood, the air entraining powder particles removed from the drum by the brush as the air flows through the dust hood. Powder particles are separated from the air as it flows through the filter bag so that only clean air reaches the motor unit.

Suitable drive means are provided to drive the drum, rotating mirror and sheet feed mechanism at predetermined speeds relative to each other, and to effect operation of the bucket-type conveyor and toner dispenser mechanism.

It is believed that the foregoing description is sufiicient for the purposes of this application to show the general operation of the xerographic reproducing apparatus. For further details concerning the specific construction reference is made to copending Gilber A. Aser et al. application, Serial No. 332,653 filed concurrently herewith and now Patent No. 3,221,622 and to portions of this specification wherein specific elements cooperating with the sheet feed mechanism are illustrated and described although they form no part of the instant invention.

Referring now to the drawings, there is provided a frame for supporting the components of the apparatus formed by a base plate 10 supported on legs 9. Vertical outboard and

inboard frame plates

11 and 12, respectively, are secured to base plate 10 in spaced relation to each other.

The xerographic drum 20 is mounted on a horizontal driven shaft and the drum is positioned between

frames

11 and 12, with the major xerographic components of the machine mounted around the drum.

Paper separated and fed by the sheet feed mechanism is further advanced by a paper transport 44 to a sheet registration device 45, constructed in accordance with the invention, whereat the lea-ding edge of a sheet is aligned and then advanced to the xerographic drum in registration with a previously developed image thereon. Transfer of the developed image on the drum to the sheet of paper is effected electrostatically by corona transfer device 51. After transfer, the sheet is separated from the drum by sheet pick-off device 52, the sheet dropping onto endless conveyor to be forwarded thereby to fuser In the embodiment of the xerographic apparatus shown, paper transport 44, sheet registration device 45, corona transfer device 51 and endless conveyor 55 are supported on a frame assembly formed as a separate unit from the main frame of the machine. The frame assembly supporting these elements may be moved as a unit away from the xerographic drum to permit access to the paper path.

As shown, the frame assembly includes an outboard frame 501 and an inboard frame 502 held in rigid spaced relation to each other by tie bars 503 which also support one portion of drawer slides 504, the mating portions of which are secured to angle rail supports 595 fastened to the base plate 10 of the main machine frame.

The paper transport 44 includes a transport frame hav ing a guide plate 510 and depending

side plates

511 and 512 to support the remaining components of the paper transport.

The

side plates

511 and 512 of paper transport 44 are secured to outboard frame 501 and inboard frame 502, respectively, by angle brackets 513, secured to the side plates as by Welding, and by screws 514 to the frames.

A plurality of endless belts 521 are looped about an idler roller 522 and a drive roller '523. Idler roller 522 is journaled in bearings 524 positioned in bearing brackets 525 secured to

side plates

511 and 512. Drive roller 523 is journaled in bearings 526 retained by the recessed apertured portions of

side plates

511 and 512 and held in axial alignment by collars 527. The drive roller is driven by chain 530 engaging sprocket 528 fixed to the inboard end of the drive roller.

The sheets are'held in engagement with the belts by ball weights 531 carried in

ball retainer brackets

532 and 533 secured to ball carrier bracket 534 supported by

spacers

535 and 536 secured to

side plates

511 and 512 whereby the ball weights will be in contact with the belts 521 or with a sheet therebetween.

In addition, a paper guide 519 is secured on spacers 536 to prevent the leading edge of a sheet from being deflected as it strikes the actuator of count limit switch 8LS. Limit switch 8L8 is mounted below guide plate 510 with its actuator extending through a suitable slot in the guide plate into the path of travel of a sheet.

To insure alignment of the right hand edge of a sheet, as seen in FIG. 4, against the inboard end of guide plate 510, an edge guide 515 is adjustably secured to the underside of the guide plate by slide plate 516 fastened to guide plate 510 to effect proper side registration by jagging each sheet approximately one-eighth inch. One end of leaf spring 517 is secured to the underside of guide plate 510, the free end of the spring being provided with an aperture to receive ball detent 518 adapted to engage suitably spaced apertures in the edge guide whereby the edge guide can be adjusted for various size sheets.

To prevent delivery of multiple or superposed sheets, a multiple sheet sensing device is used to sense the presence of superposed sheets and thereby control the operation of a diverter to discharge these superposed sheets rather than allowing them to be transported to the drum.

The sheet sensing device includes an adapter arm 541 suported at one end on spacer 536 and at its other end on a spacer rod 537. The adapter arm 541 is adjustable about the axis of spacer 536 whereby the opposite end of the adapter arm can be positioned at a predetermined height or functional setting above one idler roller 522. Adjustment of this height of the adapter arm is effected by

screws

542 and 545 threaded in the bifurcated ends of the adapter arm into contact with the spacer 537.

When the adapter arm is correctly positioned, screws 542 are locked into position by nut 543 and then the screw 544 threaded into the opposite end of this arm, is used to lock the adapter arm to spacer 536.

A multi-feed sensing limit switch 9LS is mounted on switch bracket 551 secured to adapter arm 541, with the actuator of the limit switch positioned to be actuated by the free end of a pivot arm 546.

The pivot arm 546 is pivotally secured at one end by pin 547 to the adapter arm. Sheet sensing roller 548 is journaled to pivot arm 546 intermediate its ends. A button 549 is fixed to the pivot arm to contact limit switch 9L8 before its actuator can be moved sufficiently to damage this switch.

The adapter arm is positioned, as previously described, to permit contact between the sensing roller and a single sheet as it is advanced by the belts without causing the operation of the limit switch 9LS, a normally open switch. However, when more than a single sheet passes between the idler roller 522 and the sensing roller, the sensing roller will rise to allow the multiple or superposed sheets to pass and thereby rock the pivot arm sufiiciently to actuate the limit switch 9LS to a closed position, for a purpose to be described.

As previously described, the multiple sheet detecting device is used to effect operation of a sheet diverter, which, in the apparatus shown, forms part of a sheet registration device, generally identified by reference character 45.

In the normal operation of the sheet feed system, that is, when a single sheet has been separated from the stack and fed to the paper transport, the sheet is advanced toward the drum by the paper transport 44. Single sheets thus advanced are guided by feed table or paper guide 580 toward another set of

feed rollers

601 and 602 which will direct the sheet into contact with the peripheral surface of the xerographic drum. Before this sheet can be advanced into the bite of the

feed rollers

601 and 602 its forward progress is stopped by a register stop 561 positioned in front of these feed rollers in the normal paper path.

The register stop 561 is used to align the leading edge of the sheet parallel to the axis of the drum and to restrain the forward progress of the sheet for a short period of time so that the final advancement of the sheet to the drum is timed for proper registration with a developed xerographic image previously formed on the drum.

The register stop 561 is provided at opposite end-s with pins 562 journaled in suitable bearings mounted in inboard and

outboard frames

502 and 501, respectively. The inboard end of the register stop has a depending portion to which is secured a spring bracket 563 and a cam follower 564. Cam follower 564 is forced into engagement with a cam 571 by means of spring 565 connected at one end to spring bracket 563 and at its opposite end to pin 566 secured to inboard frame 502.

The cam 571 is fixed to shaft 572 suitably journaled in outboard frame 501 and inboard frame 502. This shaft is rotated by means to be described at a speed directly related to the drum speed, which speed is also related to the speed of scanning of an image for projection onto the drum. The register stop is pivoted out of interference relation to a sheet to allow the sheet to be advanced to the drum at a predetermined interval after start of scanning as controlled by the fall of the scan cam and its rate of rotation with respect to the drum.

As shown, shaft 572 is journaled in

bearings

573 and 574 mounted in inboard and

outboard frames

502 and 501, respectively. A spacer 575 encircles shaft 572 between cam 571 and inboard frame 502, and a sprocket 576 and clutch cam 577 are secured to this end of the shaft.

Referring again to the table feed, generally designated 580, it includes a paper guide portion 581 and a reject gate portion 582 formed integral with each other, and a depending bifurcated portion 583 to slidably receive the grooved pin 586 of the actuator lever 587 secured to one end of stub shaft 588-. The feed table is pivotally mounted by pins 584 extending therefrom journaled in suitable bearings mounted in the inboard and outboard frame plates.

Stub shaft 588 journaled in outboard frame 501, has one end of lever 591 secured thereon, the opposite end of the lever being secured by pin 592 to the plunger of solenoid SOL2 supported by bracket 593 to the outboard frame. Solenoid SOL2 is suitably connected in an electrical circuit to limit switch LS-9. When the solenoid SOL-2 is energized by closure of limit switch 9LS because of the sensing of superposed sheets, will retract its plunger causing lever 591 and therefore actuator lever 587 to rotate clockwise, as seen in FIG. 8, causing the feed table 580 to rotate in the opposite direction bringing the reject gate portion into the path of paper travel to deflect the paper downward against

paper deflectors

594 and 595 which guide the paper into a paper catch tray 596.

Lever 591 is normally biased in a counterclockwise direction by torsion spring 589 encircling stub shaft 588. One end of the torsion spring is connected to pin 566 in frame 501 and the other end is secured to lever 591.

In the normal operation of single sheet feeding, the forward progress of a sheet is stopped for a very short period of time by the register stop 561, but as this register stop is suddenly lowered out of the path of paper travel, the sheet is advanced to the feed rolls 601 and 602 which firmly feed the sheet between

guides

611 and 612 into contact with the drum adjacent corona transfer unit 51.

The feed rolls 601 and 602 are also driven in timed relation with the peripheral speed of the drum. As shown, feed roll 601 is journaled in

frames

501 and 502 and is driven by sprocket 603.

Sprocket 603 on the feed roll 601 and sprocket 528 on driven roller 523 of the paper transport are operatively connected by chain 530 to sprocket 576 on shaft 572.

As a sheet is forwarded between guides, the sheet will contact the actuator of a limit switch 1LS suitably supported beneath guide 612.

After transfer, the leading edge of the sheet is separated from the drum by the sheet pick-off mechanism 52, the remainder of the sheet then peeling off the drum due to its own weight to fall onto the belts of endless conveyor 55 which transport the sheet to heat fuser 60.

Endless conveyor 55 includes a transverse extending guide plate 621 secured by angle brackets 626 to

frames

501 and 502; a flanged cover 624 is secured as by cam welding to the underside of guide plate 621 forming there with a vacuum manifold having a number of inlet apertures 622 formed in the guide plate and a discharge connection 623 in communication with a suitable aperture in inboard frame 502 which is connected by vacuum co-nnector 507 and by flexible conduit 625 to a vacuum pump. Suitable gaskets 506 are provided between guide plate 621 and frame 502 and between frame 502 and vacuum connector 507.

Sheets pulled toward the guide plate by suction through inlet apertures 622 are carried by belts 629 looped over idler roller 627 and driven roller 628 suitably journaled in the depending portions of guide plate 621. Driven roller 628 has a cam 629 fixed thereon to be driven in a manner to be described.

A miss detector limit switch 3L5 is secured by a suitable bracket in a position whereby the actuator of the limit switch extends through an aperture in guide plate 621 into the path of paper travel, for a purpose to be described.

As previously described, the frame assembly, carrying paper transport 44, sheet registration device 45, corona transfer device 51 and endless conveyor 55, is slidably mounted by means of drawer slides 504.

To insure proper alignment of these components with the xerographic drum, the brackets 641, secured to base plate 10, are provided with locating pins 542 adapted to engage suitable locating apertures formed in the frame 502.

The outboard frame 501 is aligned vertically by means of bearing plates 645 fixed to this frame and which are adapted to slide onto the locating plates 646 secured to base plate 10 in position to engage the bearing plates as this assembly is pushed parallel to the drum.

Complete Withdrawal of this assembly is prevented by suitable stops positioned on the drawer slides 504.

-In this positon of the assembly, the operator can remove the superposed sheets ejected into catch tray 596. The catch tray, as shown in FIG. 5, is pivotally secured by hinge 651 to a tray support 652 secured to

frames

501 and 502, whereby as the assembly is advanced over the edge of base plate 10, the feed out tray will pivot down about hinge 651. As this assembly is again returned to operativerelation with respect to the drum, the catch tray is cammed back into sheet receiving position by the cam action of spring support 652, secured to the underside of the catch tray, as it contacts base plate 10.

This entire assembly is locked into operative relation with the xerographic drum by manual operation of lever arm 661. Lever arm 661 is fixed to one end of shaft 664 journaled by

bearings

662 and 663 positoned in base plate 10, a cam follower 65 being secured to the opposite end of the shaft to engage cam 666 secured to outboard frame 501. With the lever arm 661 in the position, as shown in FIG. 2, the assembly is properly located in operative position by engagement of cam follower 665 with cam 666. The lever arm, is locked in this position by engagement of ball detent 668 with the knob 667 fixed to the opposite end of lever arm 661 from shaft 664. Ball detent 668 is supported by detent holder 671 threaded into base plate 10 and is biased into engagement with knob 667 by spring 672 positioned within the recessed portion of detent holder 671.

The Xerogr-aphic drum 20, and the object mirror during the scanning cycles are driven in synchronization with each other by means of a main drive motor M-3. Since the movement of a copy sheet, such as paper, to and from the drum must also be synchronized with the peripheral surface speed of the drum, the paper transport 44 and elements associated therewith, endless conveyor 55, fuser or fixing device 60 and inclined conveyor 65 are also driven by main drive motor M-3.

A splincd cam shaft 721 has fixed thereon five

cams

723, 724, 725, 726 and 727, for actuating five limit switches suitably positioned within the switch-mounting housing. Cam 723 is used to actuate a miss-puff pulse limit switch 2LS, earn 724 actuates a paper feed limit switch 5LS, cam 725 actuates a count pulse limit switch 7LS, cam 726 actuates a reject break circuit limit switch 10LS and cam 727 actuates a puffer limit switch 1218. Each of these limit switches is actuated in timed relation to the rotation of the xerographic drum through the drive mechanism, just described.

Other functions of the machine are energized in timed sequence from a bank of cam actuated limit switches, that is, a miss-puff pulse switch 2LS, paper feed switch SLS, count pulse switch 7L5, reject switch 1018 and puffer switch 12LS. 'I he cams actuating these switches are fixed on a shaft for rotation in synchronization with the rotational speed of the xerographic drum 20 and this shaft is driven by the main drive motor MOT-3, as previously described. As this shaft is rotated to rotate the actuating earns, the paper feed switch SLS is closed, completing a circuit to the contact 9CR-1 and contact 7CR-1B of control relay 7CR, a paper feed solenoid SOL-1 will be energized to initiate the separation and feeding of a sheet by the sheet feed device 40'. For further details concerning the specific construction of the sheet feed device 40, reference is made to copending application Serial No. 332,464 filed concurrently herewith on December 23, 1963, and now Patent No. 3,241,830 in the name of John W. Wagner. Paper is now fed from the sheet feed device onto paper transport 44 where it will actuate the count switch 8L5.

Assuming that only a single sheet has been advanced by the sheet feed device 40, the cam actuated count pulse limit switch 7LS will be actuated to complete a circuit through the normally closed contact 6LSB of no count switch 6LS and .by momentarily closed count switch 8LS to energize counter 3TR connected in parallel with a billing counter M-l. As the paper is continued to be fed, it will actuate limit switch 1LS. As the paper continues to advance, it will contact the xerographic drum and as it passes adjacent to the corona transfer device 51, the paper will adhere to the xerographic drum electrostatically and would continue to rotate with the drum unless it is removed by the paper pick-off mechanism 52. The operation of the pick-off device is effected by a solenoid SOL-3 operated valve controlled by a puffer limit switch 12LS which is actuated at this time.

In the event that a double sheet is fed instead of a single sheet by the sheet feed device 40, the multiple sheet sensing switch 9L8 will be actuated by the previously described multiple sheet detecting device, which senses the thickness of more than one sheet advanced by sheet feed device 40 to paper transport 44. As limit switch 9L8 is closed, it will through reject limit switch 10LS, which is timed to be closed at this time, close a circuit to solenoid SOL-2.

As solenoid SOL-2 is energized, its plunger will contact the actuator of no count limit switch 6L8 to close its contact 618A to lock in the circuit to solenoid SOL-2. In addition, normally closed contact 6LSB is opened to prevent counting, by opening the billing counter M-1 and the counter 3TR circuits. In addition, the plunger of solenoid SOL2 is linked mechanically to a reject gate, previously described, to deflect the superimposed sheets from the normal paper path thereby ejecting these sheets into the catch tray. Operation of the reject switch 10LS is so timed that it will open again before the following sheet advanced by the sheet feed device 40 arrives at the multiple sheet sensing device on paper transport 44.

While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications -or changes as may come within the purposes of the improvements or the scope of the appended claims:

What is claimed is:

1. A sheet handling mechanism, including:

a pair of feed rollers,

a conveyor positioned to forward sheets through a path of movement to said feed rollers,

a paper guide positioned for movement between a first position adjacent said path of movement and a second position in interference relationship with the path of movement of said sheets to deflect said sheets from said conveyor,

moving means to move said paper guide between said first position and said second position,

a sheet sensing device positioned to detect the feeding of superposed sheets through said path of movement including a sensor switch to actuate said paper guide moving means, and

an electrical control circuit including a counter, a counter switch positioned to be actuated by each sheet forwarded through said path of movement and electrically connected in series with said counter, a no-count switch having a pair of normally closed and a pair of normally open contacts, a break limit switch to de-energize the paper guide moving means, and a sensor switch electrically connected in parallel with the contacts of the no-count switch, said counter switch, and said counter,

the pair of normally closed cont-acts of the no-count switch being electrically connected in series with said counter and said counter switch,

the pair of normally open contacts of said no-count switch being electrically connected in parallel with said sensor switch to provide a holding circuit for the paper guide moving means whereby the paper guide is held in said second position after the release of the sensor switch until the opening of the contacts of the break limit switch connected in series with the normally open contacts and the paper guide moving means, thereby, resetting the electrical control circuit after the passage of superposed sheets, and

said norm-ally closed contacts being opened and said normally opened contacts being closed upon detection of superposed sheets whereby the counter will not 'be actuated upon the passing of the superposed sheets through said path of movement.

2. A sheet handling mechanism, including:

a pair of feed rollers,

a sheet sensing device positioned to detect the feeding of superposed sheets through said path of movement including a sensor switch to actuate said paper guide moving means,

a counter to indicate the number of single sheets fed through said path of movement,

a counter switch for actuating said counter, remote from and electrically connected in series with said counter and positioned in said path of movement between said sheet sensing device and said paper guide to be actuated by each sheet forwarded, and

a no-count switch electrically connected with said counter switch, said counter, said sensor switch, and said paper guide moving means, positioned to be actuated by said paper guide moving means and adapted to prevent actuation of said counter upon the passage of superposed sheets through said sheet sensing device into contact with said counter switch.

References Cited by the Examiner UNITED STATES PATENTS 625,094 5/ 1899 Dexter 271-57 2,220,073 11/ 1940 Belcker. 2,670,954 3/ 1954 Bach 271-57 2,818,252 12/ 1957 Nilsson 271-57 FOREIGN PATENTS 888,065 1/1962 Great Britain.

ROBERT B. REEVES, Primary Examiner.

S. ALPERT, Assistant Examiner.

Claims

1. A SHEET HANDLING MECHANISM, INCLUDING: A PAIR OF FEED ROLLERS, A CONVEYOR POSITIONED TO FORWARD SHEETS THROUGH A PATH OF MOVEMENT OF SAID FEED ROLLERS, A PAPER GUIDE POSITIONED FOR MOVEMENT BETWEEN A FIRST POSITION ADJACENT SAID PATH OF MOVEMENT AND A SECOND POSITION IN INTERFERENCE RELATIONSHIP WITH THE PATH OF MOVEMENT OF SAID SHEETS TO DEFLECT SAID SHEETS FROM SAID CONVEYOR, MOVING MEANS TO MOVE SAID PAPER GUIDE BETWEEN SAID FIRST POSITION AND SAID SECOND POSITION, A SHEET SENSING DEVICE POSITIONED TO DETECT THE FEEDING OF SUPERPOSED SHEETS THROUGH SAID PATH OF MOVEMENT INCLUDING A SENSOR SWITCH TO ACTUATE SAID PAPER GUIDE MOVING MEANS, AND AN ELECTRICAL CONTROL CIRCUIT INCLUDING A COUNTER, A COUNTER SWITCH POSITIONED TO BE ACTUATED BY EACH SHEET FORWARDED THROUGH SAID PATH OF MOVEMENT AND ELECTRICALLY CONNECTED IN SERIES WITH SAID COUNTER, A NON-COUNT SWITCH HAVING A PAIR OF NORMALLY CLOSED AND A PAIR OF NORMALLY OPEN CONTACTS, A BREAK LIMIT SWITCH TO DE-ENERGIZE THE PAPER GUIDE MOVING MEANS, AND A SENSOR SWITCH ELECTRICALLY CONNECTED IN PARALLEL WITH THE CONTACTS OF THE NO-COUNT SWITCH, SAID COUNTER SWITCH, AND SAID, COUNTER, THE PAIR OF NORMALLY CLOSED CONTACTS OF THE NO-COUNT SWITCH BEING ELECTRICALLY CONNECTED IN SERIES WITH SAID COUNTER AND SAID COUNTER SWITCH, THE PAIR OF NORMALLY OPEN CONTACTS OF SAID NO-COUNT