04/834695

11/09/1971

06/19/1969

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Eastman Kodak Company (Rochester, NY)

399/161

226/92, 242/556, 399/116, 242/562.100, 156/502

G03G15/00; B65H19/18; G03G15/00

355/3,14,16,17 352/126 226/91,92 242/58.1-58.6

3520604	PHOTOELECTROSTATIC COPIER	July 1970	Shelffo
3552957		January 1971	Hodges

IBM Technical Disclosure Bulletin, Vol. 6, No. 10, Mar. 1964, "Automatic Loading and Unloading for Cartridge Contained Magnetic Tape.".

Matthews, Samuel S.

Greiner, Robert P.

I claim

1. In electrophotographic apparatus of the type having an endless operative path and means for repetitively moving an electrophotosensitive web around said endless operative path, the improvement comprising:

2. means for receiving and supporting a container adapted to contain an electrophotosensitive web; and

3. means for moving a web in a received container to a location proximate said operative path; and

4. A mechanism for facilitating replacement of a flexible electrophotosensitive web in electrophotographic apparatus, which apparatus includes a means for repetitively moving an inserted electrophotosensitive web along an operative path of said apparatus, said mechanism comprising:

5. A mechanism for facilitating replacement of a flexible electrophotosensitive web in electrophotographic apparatus, which apparatus includes means for driving said web around an endless operative path, said mechanism comprising:

6. A web-threading and splicing mechanism, for use in replacing a flexible web in an electrophotographic machine, such web being of a type including a conductive layer and a photoconductive layer and having leading and trailing-end portions each with holding means formed thereon, said mechanism comprising:

7. In electrophotographic apparatus of the type adapted to utilize a flexible electrophotosensitive web member along an operative path located within the housing of said apparatus, a device for facilitating insertion of such a member into said apparatus, said device comprising:

8. The invention defined in claim 5 wherein said receiving means includes means operable in said receiving position for positioning an inserted container for cooperation with said opening means upon movement of said receiving means to said inserting position.

9. The invention defined in claim 5 wherein said apparatus includes means for threading a web of electrophotosensitive material along said operative path and said positioning means directs the leading end of a received web to a position for engagement by said threading means

10. In electrophotographic apparatus of the type having an operative path on which an electrophotosensitive web is utilized in reproduction operations, the combination comprising:

11. The invention defined in claim 8 wherein said cartridge includes frangible means for maintaining said cartridge closed and further comprising means in said apparatus for breaking said frangible means and opening said supported cartridge upon movement of said supporting means from said first position to said second position.

12. The invention defined in claim 9 further comprising means responsive to movement of said supporting means from said first position to said second position for rotating said cartridge a predetermined distance to position said leading end of said web material proximate said operative path.

13. In electrophotographic apparatus having an operative path and adapted to utilize a length of electrophotosensitive web material along said operative path, a device for inserting such a length of web material into said operative path, said device comprising:

14. In electrophotographic apparatus having an endless operative path and adapted to utilize a length of flexible electrophotosensitive web having a leading portion and a trailing portion, a mechanism for inserting such a length of web into said operative path, said mechanism comprising:

15. The invention defined in claim 12 wherein said means for coupling the trailing portion of the web length couples the trailing portion to said threading means.

16. The invention defined in claim 12 wherein said threading means includes means for engaging the leading portion and the trailing portion of such a web length.

17. The invention defined in claim 12 wherein said threading means includes stud means for engaging the leading and trailing portions of such a web length through openings formed in the web length near the leading and trailing portions.

18. The invention defined in claim 12 further comprising means for producing slack in a web along said operative path to facilitate coupling the trailing portion of the web length to the leading portion of the web length.

19. The invention defined in claim 12 further comprising means for receiving a cartridge containing such a length of web material to be inserted along said endless operative path and means cooperating with a received cartridge for positioning the leading portion of length of web therein for coupling with said threading means.

20. The invention defined in claim 12 further including means for providing a continuous electrical connection to said threading means during its movement around said endless path.

21. In electrophotographic apparatus having an endless operative path, a web-threading and splicing mechanism for use with an electrophotosensitive web having a leading portion and a trailing portion, each of said portions having a plurality of slots therein, said mechanism comprising:

22. A web-threading and splicing mechanism, for use in inserting a flexible web having a leading portion and a trailing portion into an endless path in electrophotographic apparatus, said mechanism comprising:

23. A drive mechanism for an electrophotographic machine, which machine includes a flexible web mounted for movement along an endless path, comprising:

24. The invention defined in claim 21 wherein each of said opposite ends of said web includes a plurality of slots; and

25. The invention defined in claim 21 further including means for providing an electrical connection to said towbar during its movement around said endless path.

26. In combination with electrophotographic apparatus having an endless operative path and means for utilizing a flexible electrophotosensitive web moved around said endless operative path, a device for removing a web from said operative path, said device comprising:

27. In combination with electrophotographic apparatus having an endless operative path and means for utilizing a length of flexible electrophotosensitive material supported around said endless operative path with the ends of the supported length coupled; a device for removing such a web from the operative path of said apparatus, said device comprising:

28. The invention defined in claim 25 wherein said means for uncoupling the ends of the web includes:

29. The invention defined in claim 25 wherein said apparatus includes a towbar movable around said operative path and both web ends of a web on the operative path are coupled to said towbar and wherein said means for uncoupling the web ends includes:

30. The invention defined in claim 27 including guide means adjacent said operative path for directing an uncoupled web end away from said operative path.

31. The invention defined in claim 28 wherein said second moving means cooperates with said guide means to feed the uncoupled web end away from said operative path and wherein said second moving means is adapted to subsequently uncouple the other end of the web.

32. The invention defined in claim 25 further including means for supporting a container and means for guiding said one uncoupled web end into said container.

33. In electrophotographic apparatus having an endless operative path and means for moving said utilizing a flexible electrophotosensitive web around said endless operative path and in which such web has opposite ends coupled to provide an endless belt around said operative path, the improvement comprising means in said apparatus for uncoupling the ends of a web located around said operative path to facilitate removal of that web from said apparatus.

34. An electrophotosensitive member adapted for insertion and repetitive use in electrophotographic apparatus along an endless operative path in such apparatus, said member comprising

35. An electrophotosensitive member adapted for insertion and repetitive use in electrophotographic apparatus along an endless operative path in such apparatus, said member comprising:

36. An article of manufacture comprising in combination:

37. A method of inserting along an endless operative path of an electrophotographic apparatus, a length of electrophotsensitive web having leading and trailing ends, said method comprising:

38. The invention defined in claim 35 further including the step of temporarily shortening the length of the path around which said web is threaded and wherein said securing step includes restoring said path to its operative length to effect engagement of said trailing web end.

39. A method of removing from electrophotographic apparatus a length of electrophotosensitive web material disposed around an endless operative path of the apparatus, said method comprising:

40. A method of removing from electrophotographic apparatus a length of electrophotosensitive web material disposed around an endless operative path of the apparatus, said method comprising:

41. A method of replacing an electrophotosensitive web on the endless operative path of electrophotographic apparatus, said method comprising:

42. In electrophotographic apparatus of the type having an endless operative path and means for repetitively moving an electrophotosensitive web around said endless operative path, the improvement comprising:

43. means for engaging and threading a web by its leading end around said endless operative path; and

44. means for coupling the leading end of the web to the trailing end of the web so as to form an endless electrophotosensitive belt extending around said endless operative path;

45. means for uncoupling the ends of an electrophotosensitive web on said endless operative path; and

46. means for moving the uncoupled web away from said endless operative path.

47. In electrophotographic apparatus of the type having an endless operative path and means for repetitively moving an electrophotosensitive web around said operative path, the improvement comprising:

48. In electrophotographic apparatus of the type having an external housing and adapted to utilize an elongated strip of flexible electrophotosensitive web member along an endless operative path located within the housing of said apparatus, a device for automatically inserting such a member into said apparatus, said device comprising:

49. In electrophotographic apparatus of the type having an endless operative path around which an electrophotosensitive web is repetitively moved in reproduction operations, the combination comprising:

50. A web threading and splicing mechanism, for use in inserting a flexible web having a leading portion and a trailing portion onto an endless operative path in electrophotographic apparatus, said mechanism comprising:

CROSS-REFERENCE TO RELATED APPLICATIONS

Reference is made to U.S. application Ser. No. 835,128 entitled "Openable Cartridge for Facilitating Egress and Ingress of Strip Material," filed June 20, 1969, in the name of Clifford B. Bushnell; U.S. Ser. No. 834,702, entitled "Web Take-up Device," filed June 19, 1969 in the name of Arthur C. Rissberger, Jr.; and U.S. Ser. No. 835,095, entitled "Apparatus and Method for Clearing the Development Plane of Magnetic Brush Developing Apparatus," filed June 20, 1969, in the name of Roger A. Drexler.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the fields of electrophotography and web handling. More specifically, this invention relates to electrophotographic apparatus adapted to utilize electrophotosensitive members in the form of an endless web and to articles of manufacture, mechanism and procedures for facilitating the supply, removal and/or replacement of such electrophotosensitive members.

2. Description of the Prior Art

In a common form of electrophotography, and electrophotosensitve member is utilized to form an electrical image in response to imagewise actinic radiation. The electrophotosensitive member includes a photoconductive layer with a conductive backing. In accordance with this known form of electrophotography, such an electrophotosensitive member is transported through a series of operation stations including a charging station at which a uniform charge is placed on the photoconductive layer, an exposure station at which the charged photoconductive layer is imagewise exposed to actinic radiation to create an electrostatic image, a developing station at which the electrostatic image is contacted with finely divided charged toner particles that adhere to the photoconductive layer in a configuration defined by the electrostatic image, a transfer station at which toner particles are transferred in the image configuration to a receiving surface, and a cleaning station at which residual toner is removed from the photoconductive layer so that it can be reused. In certain modifications of this same system one or more of these stations are commonly eliminated.

In such applications, in which the electrophotosensitive member is continually reused, the literature suggests that the electrophotosensitive member can be constructed in the form of a drum, a plate or an endless web. The endless web configuration has certain advantages over drums and plates. Among these advantages, is flexiblity of machine design for such a web can be disposed in flat configuration at one location in the apparatus to facilitate some operations such as, e.g., exposure and in a curved configuration at other locations to facilitate such other operations as the separation of a transfer sheet therefrom.

It has been found that after extended repetitive use, the photoconductive elements of such apparatus lose some of their photoconductive properties and should be replaced or removed and cleaned or rebuilt. Because there are substantial advantages in ease and expense of manufacture of an electrophotosensitive web compared to both drums and plates, a web member can be replaced more economically than drums and plates. Therefore, the use of web electrophotosensitive members in such machines has the potential for facilitating maintenance of higher and more uniform quality reproduction in such apparatus.

However, the advantages of endless web type electrophotosensitive members that are pointed out above heretofore have been substantially offset by the difficulty and inconvenience in replacing such members. Further, used members often carry particles of toner and present a problem in handling during disposal of such members.

Therefore, in order to take advantage of the attributes of the endless web system described above, I have devised a system for supplying, removing and/or replacing of such web members in a simple and convenient manner.

SUMMARY OF THE INVENTION

It is an object of this invention to provide for use with electrophotographic apparatus of the type using a continuous web electrophotosensitive member, articles of manufacture, mechanism and methods for facilitating supply, removal and/or replacement of the electrophotosensitive web.

Another object of the present invention is to provide improved means and method for feeding a web of electrophotosensitive material into an operative position in electrophotographic apparatus which utilizes such webs along an endless path.

Yet another object of the present invention is to provide improved means and method for removing a web of electrophotosensitive material from its operative position along an endless path in electrophotographic apparatus.

Still another object of the present invention is to provide means and procedures for replacing a used electrophotosensitive web in operative position along an endless path in electrographic apparatus with a new electrophotosensitive web.

Another object of the present invention is to provide means and procedures for such web replacement which do not require handling of either the new or used electrophotosensitive web.

Another object of the present invention is to provide a novel electrophotosensitive web and container which each facilitates such web replacement in electrophotographic apparatus.

In a preferred embodiment according to the present invention, a mechanism is provided for receiving a lighttight cartridge containing an electrophotosensitive web to be inserted into electrophotographic apparatus. When actuated by an operator, the mechanism opens the cartridge and positions the leading portion of the web to be contacted by a towbar. The towbar is adapted to engage a uniquely constructed leading portion of the web and thread the leading portion along the endless path in electrophotographic apparatus along which the various stations of the apparatus, such as described above, perform operations on the web. This endless path in electrophotographic apparatus is herein termed the "operative path." Upon completion of towbar travel around the operative path, means are provided to couple a uniquely formed trailing portion of the web to the towbar, thereby splicing the leading portion to the trailing portion and providing an endless web. A device is also provided which upon actuation disengages the splice of the web ends and feeds a used web from the operative path back into the cartridge.

It is an inventive feature of a preferred embodiment of the present invention that the threading towbar is used also to move the web during its copy-producing or "normal" use in the electrophotographic apparatus.

It is another inventive feature of a preferred embodiment of the present invention that connection between the ends of a web is facilitated by structure on the towbar web whereby the towbar is insertable into receiving slots provided in each of the leading and trailing portions of the web.

It is another inventive feature of a preferred embodiment of this invention that both the splicing and unsplicing operations are assisted by means for reducing the length of the endless web path in the apparatus from the length during normal or copy-producing operation of the machine, this path-length-reducing means creating slack in a web on the path which facilitates the splicing and unsplicing operations in the machine.

A remarkable thing about this invention is that endless web machines incorporating the present invention can be serviced with equal or more convenience than machines using electrophotosensitive drums or plates so that the advantages of the endless web usage described above can be obtained without the heretofore incumbent disadvantages. Further, replacement of the endless web can be accomplished by the machine user, eliminating a service call by specially trained personnel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an electrophotographic machine illustrating one manner in which an endless electrophotosensitive web and web replacement mechanism in accordance with the present invention can be arranged;

FIG. 2 is a plan view of the electrophotosensitive member shown in FIG. 1 with a portion removed and unfolded with its ends in a disconnected relation;

FIG. 2a is a sectional view of the electrophotosensitive member shown in FIG. 2, taken along the line 2a--2a;

FIG. 2b is a sectional view of the electrophotosensitive member shown in FIG. 2, taken along the line 2b--2b;

FIG. 3 is a perspective view of a cartridge adapted for use in accordance with the present invention and with an electrophotosensitive web in accordance with teachings of the present invention stored in a coiled configuration therein;

FIG. 4 is a partial perspective view of the cartridge shown in FIG. 3 but showing the opposite end;

FIG. 5 is a front view of the cartridge shown in FIG. 3 with a portion removed for illustration;

FIG. 6 is a partial sectional view of the cartridge shown in FIG. 3, the view being taken in direction 6--6 indicated in FIG. 5;

FIG. 7 is a perspective view of a transport mechanism for an electrophotosensitive web such as is schematically shown in FIG. 1 and embodying features of the present invention;

FIG. 8 is an enlarged exploded view of the joined ends of the web shown in FIG. 7 and illustrating their positional relation in the electrophotographic apparatus during normal operation of the apparatus;

FIG. 9 is a view similar to FIG. 8 but showing the relation of a leading end of a web in a magazine prior to connection with the cooperating member of the electrophotographic apparatus;

FIG. 10 is a view similar to FIG. 8 but showing the trailing end of the web just prior to connection to the cooperation member of the electrophotographic apparatus;

FIG. 11 is a side view of portions of the electrophotographic apparatus illustrated in FIGS. 1 and 7 without a web on the operative path and showing elements of an embodiment of web-feeding feeding and removing mechanism in accordance with teachings of the present invention;

FIG. 12 is a side view similar to FIG. 11 but showing elements of the web-feeding and removing mechanism at a different stage of operation;

FIG. 13 is a side view of a portion of the mechanism shown in FIG. 11 but at another stage in its operative cycle;

FIG. 13A is a sectional view taken along the line 13A-- 13A in FIG. 13;

FIG. 14 is a side view similar to FIG. 11 but showing the mechanism at yet another stage of its operative cycle;

FIG. 15 is a side view similar to FIG. 13 but showing the mechanism at still another stage of its operative cycle;

FIG. 16 is a view taken from the left end of the apparatus shown in FIGS. 1 and 7 and further illustrating certain of the elements of the mechanism illustrated in FIGS. 11-15;

FIG. 17 is a left-side view of the top portion of the mechanism shown in FIG. 16;

FIG. 18 is a right side view of the bottom portion of the mechanism shown in FIG. 16; and

FIG. 19 is a schematic diagram illustrating an exemplary circuit for controlling apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, an electrophotographic apparatus of the type with which the present invention can be advantageously used is shown. The apparatus includes an electrophotosensitive web 1 disposed on rollers and adapted to be driven along an endless operative path through cooperative relation with a series of electrophotographic stations. Electrophotosensitive web 1 is commonly constructed including a photoconductive layer with a conductive backing carried on a flexible support, for example film base. Examples of such webs and methods for their preparation can be found in U.S. Pat. No. 3,141,770, Davis et al. and for simplicity this multilayered construction of the web 1 is not illustrated in most figures of this application.

The stations of the electrophotographic apparatus include a charging station 2 which applies a uniform charge to a surface of the photoconductive layer of an operative segment of web 1, an exposing station 3 where the charged photoconductive layer is exposed to imagewise projected actinic radiation creating an electrostatic image, a developing station 4 where finely divided toner particles are applied to the electrostatic image creating a toner image on the web, a transfer station 5 where the toner image is transferred to the surface of a receiving sheet T and a cleaning station 6 where the residual toner is removed and any remaining electrostatic charge dissipated. It has been found desirable in practice of the present invention to provide that the cleaning apparatus 6 be movable between an operative position contacting a web on the path and a position spaced from the path, this movement being controlled by an eccentric 6a driven by a motor M ₂ . Of course, it will be appreciated that the cleaning station need not be movable as disclosed in FIG. 1. The transfer sheet T carrying transferred toner can be fed to a fixing station 7 where they are fused giving a final reproduction. Successive transfer sheets T can be fed from a supply station 8 to the apparatus and discharged into a storage station 9. After passing the cleaning station, one of the operative segments of the electrophotographic web 1 is ready for reuse. It is to be understood that the machine shown schematically in FIG. 1 is merely an example of an electrophotographic machine, and that the invention disclosed and claimed herein is usable with machines in which some of these stations are eliminated, combined with others or substantially changed or supplemented in function.

With such an arrangement, a large number of copies can be made by repetitive use of the operative segments of a single electrophotosensitive web. After continued use, the photoconductive layer of the web tends to lose some of its photoconductive properties as mentioned above. This occurs for a number of reasons, primary of which is that a small layer of scum builds up from the developing and cleaning processes. For purposes of replacing the photoconductive web in such a machine, a web-inserting, removing and/or replacement mechanism has been provided in accordance with the present invention. The web replacement station 10 of this mechanism is schematically shown in FIG. 1 and this mechanism subsequently will be described in detail. It subsequently will be appreciated that the web-inserting, removal and/or replacement mechanism and articles which are used therewith can advantageously be used to insert a web, to remove a web or to remove and insert, i.e., replace a web for the disclosed as well as other types of electrophotographic apparatus.

As shown in FIG. 2, the electrophotosensitive web 1, has formed along each end thereof, a series of openings 11 each of which openings includes an enlarged portion 11a and a slotted portion 11b that extends towards the adjacent web end from the enlarged portion.

In FIGS. 2a and 2b cross sections of the end 13 of web 1, hereinafter termed the leading end, and end 14, hereinafter termed the trailing end, are shown. As has been pointed out, the web 1 is a multilayered structure comprising a photoconductive layer 1a, a conductive layer 1b and a film base 1c. At trailing end 14 of web 1 it can be seen that a cover flap 15 is provided which is secured to the web 1 along one or both edges 16 so as to overlie the apertures 11 on end 14 of the web 1. This cover flap is provided to protect from developer, the edges of apertures 11 at which the electrophotographic apparatus electrically contacts the conductive grounding layer 1b.

Referring now to FIGS. 3-6 a cartridge 20 is shown which can be utilized to store unused electrophotosensitive webs such as web 1 and receive used webs of the same type for disposal.

The cartridge 20 includes a pair of circular ends 21 and 22 onto the edges of which is attached a slightly overlapping coil of protective sheet material 23. The end 21 has formed on the outer portion thereof a V-shaped retaining surface 24 which is adapted to support and orient the cartridge upon insertion in the electrophotographic apparatus for a purpose subsequently to be described.

In FIGS. 4 and 5 it can be seen that end 22 is formed with a circular opening extending through its central portion. A plug 27 is mounted for rotation in the opening of end 22 and a core 28 inside the magazine 20 is attached at one end to the inner portion of plug 27 so as to be rotatable with the plug 27. The portion of plug 27 which extends outside the cartridge is formed with central hub 27a and a pair of radial drive flanges 27b suitable for connection of rotary drive to the plug in a manner to be described.

Referring to FIGS. 3,5 and 6 it can be seen that the web 1 is wound about core 28 with the leading end 13 of web 1 extending between the overlapping portions of protective sheet 23 so as to be outside the space enclosed by the cartridge 20. It is to be noted that while the edges of sheet 23 are secured to the edges of ends 21 and 22 around the main portion of the ends circumferences, the length 29 of the coiled protective sheet 23 is not secured to the ends 21 and 22 but secured by frangible tabs 30 to the overlapped portion of sheet 23 in a novel manner described in more detail in U.S. Application Ser. No. 835,128, entitled "Openable Cartridge for Facilitating Egress and Ingress of Strip Material," filed June 20, 1969, by Clifford B. Bushnell.

Referring now to FIG. 7, the mechanism defining the operative path for the electrophotosensitive member 1 can be seen in more detail. A web 1 in its inserted position is connected at both ends 13 and 14 to a towbar 40 by hook studs 41 on the towbar 40. Referring to FIGS. 8-10 it can be seen that the hook studs 41 are formed with an enlarged head adapted to pass through the larger portions 11a of apertures 11 and securely retain the web ends 13 and 14 upon movement into slotted portions 11b of the apertures 11. The relative longitudinal relation of the web ends 13 and 14 and towbar 40 can best be seen in FIG. 8 in which the axis A shows relative longitudinal positions of the web ends 13 and 14 hook studs 41 during the copying mode of apparatus operation.

As shown in FIG. 7, towbar 40 is connected at its ends to endless toothed belts 42. Belts 42 are mounted for movement on rotatably mounted gears 43 which are located around the interior of the belt loops in a manner defining the operative path of travel for web 1 shown in FIGS. 1 and 7. The operative path of web 1 is also defined in part by a series of web transport rollers 44 which are journaled for rotation on the axis coinciding with or parallel to the rotational axis of gears 43 and which are disposed at spaced locations around the web path as shown in FIG. 7. Belt transport rollers 45 are desirably provided at the locations shown in FIG. 7 to define the downwardly inset path of travel illustrated. A web tension control roller 48 is provided at the left end of the operative path of web 1, as shown in FIG. 7, for a purpose to be subsequently described.

Additionally, an endless electrically conductive cable 46 is connected to one end of towbar 40 and grooved rollers 47 are provided to support cable 46 during movement of the towbar 40 around its path defined by the rollers 47. At least one of the rollers 47 is desirably electrically grounded and an effective ground of the conductive layer 1b of the web 1 therefore is provided from hook lugs 41, through towbar 40, cable 46 and the roller or rollers 47. If desired a conductive imbibing material can be provided on the edges of apertures 11 which contact the lugs 41 so as to enhance the ground connection to layer 1b.

When drive is transmitted in the direction indicated in FIG. 7 to one or more of the pairs of gears 43, e.g., as by a reversible motor 49 shown in FIG. 1, the belts 42, towbar 40 and electrophotosensitive web 1 connected to the towbar 40 will be moved around the path of operation in a counterclockwise direction as shown in FIG. 7. Drive can also be transmitted by the motor 49 to such of the transport rollers 44 and 45 as is desirable to facilitate transport of the web 1 along its operative path.

The web replacement station 10 that is illustrated schematically in FIG. 1 is shown in more detail in FIG. 11, and it can be seen that the station includes a hinged yoke 50 mounted on a pivot for movement between an open position, shown at I in FIG. 11, for receiving a cartridge 20 and a closed operating position shown at II in FIG. 11. The yoke 50 includes a cartridge position disc 51 having a male dart 52 for positioning cartridge 20 in yoke 50 by cooperation between dart 52 and slot 24 on the end of the cartridge. The position disc 51 contains a detent 53 for receiving a spring-biased position disc-locking lever 54 which is mounted on the yoke 50 in cooperating relation with position disc 51.

A cartridge 20 is inserted in the yoke 50 while in position I in the manner indicated in FIG. 11 and the yoke then is moved on its hinge into the cartridge housing 55, as shown at position II in FIG. 11. During movement of yoke 50 into housing 55, release lug 56 on the housing 55 intercepts the locking lever 54 and moves it out of detent 53 on the cartridge position disc 51.

The cartridge position disc 51 also has formed thereon pins 57 and 57 which, upon movement of the yoke 50 into the housing 55, are positioned in engagement with a cartridge rotation cam 58 (see FIG. 16). The cam 58 is coupled by a gear member 59 to a geared surface 60a formed on one end of cartridge rotation lever 60. As shown in FIG. 11, the cartridge rotation lever 60 is mounted on housing 55 for movement between a lower operating position and an upper position for allowing the yoke 50 to be swung out for cartridge removal and/or insertion. As cartridge rotation lever 60 is moved downwardly with yoke 50 in the housing 55, the geared surface 60a on lever 60 rotates gear member 59, which in turn rotates cartridge rotation cam 58. The above-described movements effect rotation of cartridge position disc 51 and the cartridge 20 engaged thereby approximately a one-quarter turn clockwise to the cartridge position shown in the housing in FIG. 11. Because of the cooperation between the locking lever 54 and position disc 51, the cartridge 20 is located initially in the housing 55 so that this one-quarter turn of rotation causes the frangible tabs 30 on the cartridge to be moved against a pair of cartridge-opening wedges 61 which are provided in housing 55. Cartridge-opening wedges 61 can be formed to be resiliently biased towards an inserted cartridge 20 and are located so that as an inserted cartridge 20 is rotated by actuation of cartridge rotation lever 60, the tabs 30 on the cartridge are broken or severed and the portion 29 of protective sheet 23 is moved back against a stop 62.

During the one-quarter turn rotation of the cartridge 20, leading portion 13 of the web 1 therein is guided by a web guide 63 provided in the housing 55, past a guide roller 64 at the lower portion of the housing and to the position in the path of the towbar 40 such as is shown in FIG. 11.

Referring to FIGS. 16 and 17 it can be seen that downward movement of cartridge rotation lever 60 also moves a retracting member 65 located on the opposite side of housing 55 from cam 58 to the position indicated in dotted lines in FIG. 17. Movement of member 65 to the dotted-line position allows spring 66 to move a core drive disc 67 that is rotatably mounted on the housing into engagement with the flanges 27b on the outer surface of cartridge plug 27 so that core 28 of cartridge 20 is thereafter coupled to drive disc 67. Core drive disc 67 is coupled by a drive shaft and suitable one-way clutch mechanism (not shown) to a drive pulley 68 supported on shaft 69. In FIG. 16 it can seen that shaft 69 also has mounted thereon another drive pulley 70 for a purpose subsequently to be described.

As was pointed out above, a web tension control roller 48 is provided at a location inside the web path shown in FIG. 7. The tension control roller 48 and mechanism which cooperates with that roller to selectively control the length of the endless path for a web 1 and thereby the tension of an endless web on the path are shown in more detail in FIGS. 11, 12, 14 and 16.

The tension control roller 48 is mounted for rotation on an enlarged shaft 71 which extends a distance axially beyond each end of the roller 48. The shaft 71 is mounted on a rod 72 extending through a horizontally elongated bore 73 in shaft 71 so that the shaft 71 is slidingly movable on rod 72 in a generally horizontal plane. The ends of rod 72 are mounted on the machine housing at locations spaced outwardly from shaft 71. Respectively attached to a lug 74 formed on each end of shaft 71 are a pair of positioning links 75, one of which is shown in FIGS. 11 and 12. Each link 75 has a slidable follower plate 76 and fixed follower plate 77 mounted thereon. Each of positioning links 75 also is provided with a follower spring 78 which maintains plates 76 and 77 in following contact with the cooperating rotatable tension control cams 79 which are mounted on the apparatus housing and connected to receive rotatable drive via shafts 79a from a motor M ₃ schematically shown in FIG. 1.

It can be seen that when tension control cams 79 have been rotated to the position shown in FIG. 11, the shaft 71 is moved by links 75 to its leftmost, or tension applied, position so that the roller 48 rotatably supported on shaft 71 slightly stresses and endless web 1 on the operative path of the apparatus. When tension control cams 79 have been rotated to the position shown in FIG. 12, the positioning links 75 move the ends of shaft 71 to the rightmost position shown in FIG. 12 so that the operative path is shortened and so that an endless web 1 mounted on the operative path will be relaxed.

Mounted in the electrophotographic apparatus, generally above and on the opposite side of the operative web path from tension control roller 48, are first and second splice control rollers 80 and 81, see FIGS. 7, 11, 12, 16 and 18. First splice control roller 80 is mounted on a shaft 82 which is supported at each end at a location laterally outside the web path on pivotally mounted arms 83. The shaft 82 is biased downwardly by a spring 84 towards a position where supported roller 80 contacts a web 1 on the operative path in the manner shown in FIG. 12. The second splice control roller 81 is similarly mounted on a shaft 85 supported on pivotally mounted arms 86 which are urged towards the web feed path by spring 87.

As most clearly shown in FIGS. 11, 16 and 18, cam plates 90 are mounted on each end of rod 72 at a location outside of belt gears 43 for rotation on the rod 72. Cam plates 90 are biased in a counterclockwise direction as viewed in FIG. 11 and 18 by springs 91. A pair of eccentric rollers 92 are mounted in the apparatus fixed on shaft 92a at locations for cooperative rolling contact with surfaces 90c of each of cam plates 90 and are connected via shaft 92a to a drive motor M ₁ as indicated schematically in FIG. 1. When eccentric rollers 92 are in the position shown in FIG. 11, the surfaces 90a and 90b of cam plate 90 have moved under shafts 82 and 85 of the splice control rollers 80 and 81 to move the rollers out of contact with a web 1 on the operative path of the apparatus. When the eccentric rollers 92 have been rotated to the position shown in FIGS. 12 and 18 the spring 91 moves cam plate counterclockwise to the position shown in FIGS. 12 and 18, so that surfaces 90a and 90b no longer contact shafts 82 and 85 of the splice control rollers. The springs 84 and 87 then move splice control rollers 80 and 81 into a position for contact with a web 1 on the operative path of the electrographic apparatus.

OPERATION OF WEB INSERTING MECHANISM

Assuming that no web is on the operative path and no cartridge is in the housing of the apparatus, the web-insertion operation can be commenced by actuating movement of the towbar 40 to a position Y slightly to the right, as shown in FIG. 1, of the location where the leading end 13 of a web 1 will be introduced into the path from a cartridge 20 in the housing 55. A cartridge 20 is inserted in yoke 50 and the yoke moved into the housing 55 in the manner described above. The operating handle is then moved downwardly to open the inserted cartridge and position the leading end 13 of the web in the cartridge as shown in FIG. 11.

The drive for towbar 40 is then actuated to move the towbar to the left or counterclockwise as viewed in FIG. 11 around the operative path of the apparatus. As indicated in FIG. 9, when the towbar 40 moves into contact with the leading portion 13 of web 1, the hook studs 41 move through the enlarged portions 11a of the openings 11 in the leading web portion. Continued movement of towbar 40 causes the hook studs to move into the portion 11b of the openings 11 and the web thereafter is withdrawn from the cartridge 20 and threaded around the operative path of the apparatus in a counterclockwise direction by towbar 40. The core 28 of cartridge 20 rotates freely during withdrawal of the web because the one-way clutch connecting drive disc 67 to pulley 68 does not operate in the web-unwinding direction or clockwise direction as viewed in FIG. 11.

Prior to or during the initial threading movement of towbar 40, the motors M ₁ , M ₂ and M ₃ are actuated and respectively effect movement of the rollers 80 and 81 into their operative position shown in FIG. 12, movement of cleaning station 6 to a position spaced from the operative path and movement of tension control roller 48 to its rightmost or relaxed web position shown in FIG. 12.

As the towbar 40 completes its movement around the operative path and passes the location at which it engaged the leading end of web 1, it passes under the trailing portion 14 of the web which is still partially within the egress passage from housing 55. The towbar 40 continues on its counterclockwise threading movement and stops at a predetermined location slightly beyond roller 81 as shown in FIG. 12. At this stage of the insertion operation, the trailing portion 14 of the web 1 has been removed entirely from housing 55 and has been pulled beneath roller 81 by which it is held flat against the overlapped portion of web 1. Because of the reduced length of the web path at this stage, the openings 11 in the trailing end 14 of the web 1 are slightly to the right of the studs 41 of towbar 40 as shown in FIG. 10.

At this time motors M ₁ , M ₂ and M ₃ are again actuated. Motor M ₃ effects a 180° rotation of eccentric cams 79 shifting the roller 48 to the leftmost position shown in FIG. 11. The leftward movement of roller 48 causes the trailing end 14 of web 1 to move to the left because the web end 13 is retained by the stationary towbar 40. As the end 14 moves left the enlarged openings 11a slip over the studs 41 of the towbar 40 and a slight further movement moves the web so that the studs 41 are in portions 11b of both the leading and trailing ends of the web. At this point the ends of web 1 are spliced and the web is slightly tensioned by roller 48 maintaining the towbar studs 41 in good grounding contact with the conductive layer 1b at each end of the web. Rotation of control motor M ₁ effects operation of cam plate 90 to move rollers 80 and 81 out of contact with the web to the position shown in FIG. 11. Motor M ₂ effects movement of the cleaning station 6 back to its operative position and the electrophotographic apparatus is then in a condition to proceed with normal reproducing operations with the newly inserted web.

OPERATION OF WEB REMOVAL MECHANISM

Assuming an empty cartridge 20 is provided in housing 55, removal of a used web from the operative path of apparatus is commenced by reversing the drive from motor 49 to towbar 40. When motor has moved towbar 40 in a clockwise direction to a location in the vicinity of the position indicated X in FIG. 1, motors M ₃ and M ₁ are energized to effect a 180° rotation of eccentric cams 79 and eccentric rollers 92. Rotation of cams 79 causes roller 48 to shift to the right to relax the tension on web 1 and rotation of rollers 92 releases rollers 80 and 81 into contact with the web in the same manner as described above with respect to the web insertion operation. Motor M ₂ is likewise actuated to effect movement of the cleaning apparatus 6 to its spaced position.

Referring to FIGS. 1 and 16 it can be seen that the reverse drive from motor 49 is transmitted via the toothed belts and gears 42 and 43 to a positive drive belt 111a. Drive from belt 111a is transmitted by spring belt 111 to the pulley 68 for the core drive disc 67. The counterclockwise rotation of pulley 68 effected by the reverse rotation of motor 49 is transmitted by the one-way clutch so that drive disc 67 rotates the core 28 of an empty cartridge in the housing 55 in a counterclockwise direction. Rotation of pulley 68 is also transmitted via shaft 69, pulley 70, spring belt 113 and pulley 114 to rotate roller 80 in a counterclockwise direction.

As the towbar 40 moves past the position X in a clockwise direction and passes on beneath the rotating roller 80 with roller 48 in its rightmost position to provide slack in the web, the trailing end 14 of the web 1 is disconnected from towbar 40 in the manner shown in FIGS. 13 and 13A. This disconnecting operation is facilitated by two functions performed by roller 80. Firstly, roller 80 is geared so that its peripheral surface moves at a higher linear speed than the towbar 40 passing thereunder. Because the web 1 is relaxed and slack exists in the endless web at this stage, the trailing end 14 is shifted ahead of the towbar along its path of travel by the faster moving roller 80 which contacts the end 14. This relative movement of the trailing end 14 causes the enlarged openings 11a of that end to shift into alignment with hook studs 41, see FIG. 13. Secondly, referring to FIG. 13A, it can be seen that as the towbar 40 passes beneath the roller 80, the spring bias towards tension control roller 48 causes the roller 80 to bow the towbar 40 and web end 14 thereon slightly towards the tension control roller. This bowing of the web end 14 in a transverse web direction causes the web end 14 to straighten in a longitudinal direction thereby moving the end 14 away from the towbar 40 as shown in FIG. 13. This straightening tendency of the web and the drive of roller 80 direct the trailing end away from the towbar and into a rewind passage 120 provided in housing 55.

Thereafter, as the towbar 40, with the leading end 13 of web 1 still attached, continues its clockwise movement around the operative path of the apparatus, the web is unthreaded from the operative path and fed by roller 80 into housing 55 in the manner as shown in FIG. 14.

In FIG. 14 it can be seen that the guide passage 120 formed by plates 120a and 120b directs the trailing end 14, of web 1 into the empty cartridge 20 in housing 55, through the opening presented by the displacement of portion 29 of the cartridge. Referring to FIG. 14 and to FIG. 5, it can be seen that since the core 28 of the cartridge 20 is being rotated in a counterclockwise direction, the trailing end 14 of web 1 will be directed around the interior of the cartridge and cinch itself onto the rotating core 28 in a manner described in detail in copending U.S. Application Ser. No. 834,702, entitled "Web Takeup Device," filed June 19, 1969, in the name of Arthur C. Rissberger. After cinching, the rotation of core 28 effects wind up of the unthreaded web 1 as it is fed from roller 80.

As the unthreading operation progresses, the towbar 40 with the leading end 13 of the web 1 will again approach and pass under roller 80 at which time the leading end is pulled free of the towbar by the takeup core 28.

The movement of the towbar studs 41 out of enlarged portions 11a of apertures 11 in the leading end 13 is facilitated by the configuration of the studs and the angle at which the web is being moved away from the towbar by the rotating cartridge core 28. The remaining portion of the web 1 is then wound into the cartridge by cartridge core 28. The motor 49 is then stopped.

The cartridge 20 containing the used web 1 can then be removed by lifting operating lever 60 and moving yoke 50 out of the housing 55 to provide access to the cartridge. It will be appreciated that the used web 1 in the cartridge therefore can be readily removed from the yoke and disposed of without necessity of the operator contacting the used web.

WEB-REPLACEMENT OPERATION AND CONTROL

It will be appreciated that in order to replace a used web in electrophotographic apparatus in accordance with the teachings of the present invention, as illustrated by the presently disclosed embodiment, it will be necessary only to effect a web removal operation such as described above, replace the cartridge 20 containing the used web with a new cartridge containing an unused web and effect the web-insertion operation described.

Referring now to FIGS. 1 and 19 a simplified cycle of web replacement will be described in conjunction with an embodiment of control circuitry in accordance with the present invention. It will be understood that given the teachings disclosed herein, various of the manual actuations described can be controlled automatically by sensing devices and circuits that are well within the state of the art.

In FIG. 1 it can be seen that an empty cartridge 20 is positioned in the station 10 and a web 1 is in operative position on the feed path as would be the case at the inception of a normal web-replacement operation. It is assumed for purpose of this description that the web has been sufficiently utilized so that web replacement is desired.

To commence the web replacement, switch S ₁ is opened to the position shown in FIG. 19 so that the power supply to the main drive motor 49 is only through lines L ₁ and L ₂ and the web-replacement control panel 140. The direction control switch S ₂ is then set in the reverse position shown as a solid line in FIG. 19 and the main motor drive switch S ₃ is closed to drive the towbar 40 and attached web 1 in the reverse direction (i.e., clockwise as viewed in FIG. 1) until towbar 40 has moved to a position in the vicinity of the range X shown in FIG. 1, and then released, i.e., opened. It is desirable for purposes described in detail in copending U.S. Application Ser. No. 835,095, entitled "Apparatus and Method for Clearing the Development Plane of Magnetic Brush Developing Apparatus," filed June 20, 1969 in the name of Roger A. Drexler, that the motor 49 operates in the reverse direction for a period sufficient to rotate the magnetic brushes B ₁ and B ₂ in the developing station one-half rotation clockwise. As described in that application such reverse rotation clears the development plane of the developing station 4 of developer for the remainder of the web-replacement operation.

When the towbar 40 has been moved to a position near the range X, the switch S ₄ is closed to effect release of the clutch mechanism 142 coupling drive from the main drive motor 49 to the developing station 4. The brushes B ₁ and B ₂ therefore do not rotate during the remainder of the web-replacement operation.

At this stage, three-pole switch S ₅ is momentarily closed and causes an approximately 180° rotation of auxiliary motors M ₁ , M ₂ and M ₃ . This controlled rotation is effected by energization of relays R ₁ , R ₂ and R ₃ which respectively close motor control switches 151, 152 and 153. When switches 151, 152 and 153 are closed, and when normally closed microswitches 154, 155 and 156 are closed, relays R ₁ , R ₂ and R ₃ remain energized after three-pole switch S ₅ is released. It is noted that motors M ₁ , M ₂ and M ₃ are connected in parallel with relays R ₁ , R ₂ and R ₃ , respectively, so the they operate together, Therefore, three pole switch S ₅ need be depressed only long enough to close switches 151, 152 and 153. As indicated in FIGS. 1 and 19 switching cams 161, 162 and 163 are respectively rotated in a counter clockwise direction by motors M ₁ , M ₂ and M ₃ , and after 180° of rotation, opened and then moved slightly past their respective microswitches 154, 155 and 156 by the inertia of the motors. The relays R ₁ , R ₂ and R ₃ maintain their respective switches in a closed condition until the microswitches 154, 155 and 156 are momentarily opened at which time they release the switches 151, 152 and 153 stopping the current to motors M 1, M ₂ and M ₃ .

The incremental rotation of motor M ₁ effects the 180° rotation of eccentric rollers 93 and allows cam plate 90 to move to the position shown in FIG. 18. The rollers 80 and 81 therefore are moved into the operative position along the machine feed path. The incremental rotation of motor M ₃ causes 180° rotation of control cams 79 and allows tension control roller 48 to move to the right as shown in FIG. 12. The incremental rotation of motor M ₂ similarly effects a 180° rotation of eccentric 6a which allows the cleaning station 6 to move away from the web path.

With the direction control switch S ₂ still in the reverse position the main motor drive switch S ₃ is closed and held in a closed position until the web 1 is removed from the operative path and rewound into the cartridge in the manner described above with respect to the removal mechanism operation. It is to be noted in FIG. 1 that reverse drive of the main motor 49 is transmitted to rotate the core drive disc 67 and roller 80 in a counterclockwise direction to effect separation and takeup of the used web in the manner also described with respect to the web-removal mechanism. When the web has been fed completely back into the cartridge and the towbar has moved to a position in the vicinity of the position Y shown in FIG. 1, the main motor control switch S ₃ is released, i.e., opened.

After the cartridge containing the old web has been removed a new cartridge is inserted and the leading end of a new web is positioned along the operative path by the mechanism in housing 55 previously described.

At this stage the direction control switch S ₂ is moved to the forward drive position shown in FIG. 19. The threading switch S ₆ is then depressed, i.e., closed and held until the towbar 40 has picked up and moved the leading end of the new web in a forward direction past the microswitch 167, see FIGS. 7, 12 and 19. It is to be pointed out that microswitch 167 is physically located on one of the arms 86 supporting roller 81 and is moved into an operative position along the path of towbar 40 when rollers 80 and 81 are lowered. After the towbar 40 has moved the leading end of the new web in the forward direction past the switch 167, the threading switch S ₆ is released, i.e., opened. Relay R ₄ having been energized, closes and retains double pole switch 170 closed to that current passes to the main drive motor 49 in the forward mode until towbar 40 has completed its movement around the path and opens microswitch 167. At this time the relay R ₄ is deenergized and drive of the towbar 40 is stopped with the towbar in the position shown in FIG. 12.

Next, three-way switch S ₅ is again momentarily actuated and the motors M ₁ , M ₂ and M ₃ move another 180° back to the original position to retract rollers 80 and 81, reposition the cleaning station 6 and move roller 48 back to its original position to complete joining and tensioning of the newly inserted web. Switch S ₁ is then closed and the web movement is again placed under control of the machine logic for normal copy reproduction operation.

The invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.