US3617124A

US3617124A - Electrographic copying machine

Info

Publication number: US3617124A
Application number: US867496A
Authority: US
Inventors: Orville C Haugen; Emil J Kvaal
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1969-10-20
Filing date: 1969-10-20
Publication date: 1971-11-02
Anticipated expiration: 1988-11-02
Also published as: NL7014827A; ZA707084B; JPS4922660B1; GB1329099A; SE354934B; CH524164A; FR2066149A5; CA928551A; AT311793B; DE2052836A1

Abstract

A system for handling and transporting the intermediate web in an electrographic copying machine which utilizes an intermediate web to produce copies of graphic intelligence. The system comprises a cartridge formed of two molded shells which contain a supply of intermediate web wound between two rollers. The rollers extend beyond the sides of the cartridge and a section of the web between the rollers is disposed externally to the cartridge. The cartridge is removably mounted on a movable carriage having a flat conductive peripheral support area supporting said external web section. Means is provided to transport the carriage thus moving the supported section of web in proper sequence from an imaging system or exposure station to a development and a transfer station on the copying machine and to then return the carriage to the imaging station in order to produce the desired copies. Drive means is provided on the machine to change the section of web disposed externally to the cartridge as is needed in producing subsequent copies. The web change is accomplished by winding the web from one roller onto the other.

Description

United States Patent [72] Inventors Orville C. Haugen Bloomington; Emil J. Kvaal, North St. Paul, both of Minn. 21 Appl. No. 867,496 [22] Filed Oct. 20, 1969 [45] Patented Nov. 2, 1971 [73] Assignee Minnesota Mining and Manufacturing Company St. Paul, Minn.

[54] ELECTROGRAPHIC COPYING MACHINE 7 Claims, 7 Drawing Figs.

[52] 0.5. CI 355/16, 355/72, 355/66, 355/65, 355/27 [51] Int. Cl 603g 15/00 [50] Field oiSenrclL. 355/16, 3, 107, 72, 64, 65

[56] References Cited UNITED STATES PATENTS 3,432,231 3/1969 Gordner 355/16 3,490,844 1/1970 Sapp 355/40 Primary Examiner-Samuel S. Matthews Assistant Examiner-D. .l. Clement Attorney-Kinney, Alexander, Sell, Stedt & Delahunt ABSTRACT: A system for handling and transporting the intermediate web in an electrographic copying machine which utilizes an intermediate web to produce copies of graphic intelligence. The system comprises a cartridge formed of two molded shells which contain a supply of intermediate web wound between two rollers. The rollers extend beyond the sides of the cartridge and a section of the web between the rollers is disposed externally to the cartridge. The cartridge is removably mounted on a movable carriage having a Hat con ductive peripheral support area supporting said external web section. Means is provided to transport the carriage thus moving the supported section of web in proper sequence from an imaging system or exposure station to a development and a transfer station on the copying machine and to then return the carriage to the imaging station in order to produce the desired copies. Drive means is provided on the machine to change the section of web disposed externally to the cartridge as is needed in producing subsequent copies. The web change is accomplished by winding the web from one roller onto the other.

PATENTEUmv 2 l9?! SHEET 2 IF 4 f CZMM INVIi 'I'URS d /m5 HUGE/Y BY MIL Arm/Wa PATENTEDNUV 2 Ian SHEET 3 OF 4 J n 6 MM W M W.V 4 WC z a ELECTROGRAPHIC COPYING MACHINE This invention relates to a new and improved electrographic copying machine and in one aspect an improved mechanism for handling a photoconductive intermediate web to supply the same and to bring the web into operative contact with several stations to produce copies of an original document.

Heretofore in prior art copying machines utilizing an intermediate web, the web has been wound between two rotatable rollers mounted directly on the copying machine. One system comprises a web supply roll, means to form a path past the various processing stations in the copying machine, a takeup roll, and a means for advancing the web between the supply and the takeup roll and in so doing to move it past various processing stations. This moving web system allows the use of generally flat processing stations which are normally less complex in nature, however, to replace an intermediate web in this system requires the awkward and tedious task of removing the roll of used intermediate paper and then loading and threading the new web through the machine and attaching the free end to the takeup roll. This task of changing rolls of intermediate web is not only time consuming, but also requires a certain level of training for the office personnel servicing the machine.Additionally, the strength of the intermediate web is a factor in limiting the speed at which the web can be moved through the machine; thus limiting the speed of copy production. Also, elaborate web handling, timing and drive mechanisms are required to advance the web past the required stations and subsequently rewind a portion of the web toward the imaging station in order to avoid wasting the length of web between successive exposed sections.

The types of intermediate web-handling systems for electrographic copy machines include the use of an endless web, or mounting the supply and takeup rolls for the intermediate web in a support drum and threading the web from one roll to the other about a peripheral portion of the drum. The web is advanced during or after exposure to a developing position on the drum which is pennanently and rotatably mounted on the copying machine. The drum rotates the exposed section of the intermediate web in an arcuate path past fixed processing stations to produce a copy of an original document. One form of such a machine is illustrated in the copending application of James G. Moxness, Harold l-l. Nelson, and Edward A. OMara, Ser. No. 640,547, assigned to the assignee of this application. The system-of the Moxness et al. application removed some of the disadvantages previously involved with moving the web through the machine. However, the disadvantages of having to load, unload and thread the web, and to move the web relative to the support to achieve the exposure, development or the transfer and to time the web movement and drum movement with these process steps remained.

The electrographic copy machines utilizing an endless web are generally of the xerographic type and in these machines control of the web position or location as well as elaborate web drive and steering mechanisms are required to produce copies. These webs must also be cleaned between the production of successive copies, which presents further problems.

The present invention eliminates the disadvantageous features involved with loading and unloading loose rolls of intermediate web as practiced in the prior art.v

In the present invention the web handling and threading by the machine operator is reduced to a minimum. The positioning of the web on the web supply or takeup rollers so that it steers properly and without wrinkling is all handled by the web supplier as the ends of the web are secured to the rollers within the supply cartridge. The process of changing the intermediate web merely requires substitution of one cartridge for another. This substitution is accomplished after opening a gate on the movable carriage by inserting the cartridge, and closing the gate.

The present machine does not require movement of the web relative to its support between or during any of the copy process steps. This reduces the chance of misalignment of the image with the receptor or copy sheet.

In the present invention, the carriage supporting the exposed section of web is movable with and not relative to the web during any of the process functions of the copy machine in making each copy. A high rate of copy production is possible without the limitations and problems previously mentioned in connection with a conveying system.

The machine of the present invention affords projection of the image onto the web disposed on a plane, the development is handled with the web positioned on the same plane in the same relative position to the plane, the plane is movable along a restricted path relative to the processing stations and control is easily maintained.

The inertial forces to be anticipated in a reciprocal system are effectively minimizer in the present invention by a carriage drive system which provides gradual acceleration and deceleration at the respective ends of the path traversed by the carriage, thus allowing a high rate of copy production.

The copying machine of this invention is adapted to produce a copy of graphic intelligence via a photoconductive intermediate web material where the process includes exposure of a section of intermediate web at an imaging system or imaging station supported on the copy machine when the intermediate web material is oriented at the imaging station, developing the image at a developing station by depositing a particulate material on the image areas in the presence of an electric field when the exposed section of the web material is moved past the developing station, and transferring the particulate imagewise pattern to a receptor or copy sheet at a transferring station to produce a copy of the graphic intelligence when the developed section of web material is moved past the transfer station. The web is supplied to the machine of this invention by a cartridge comprising two molded shells, two rotatable rollers and a supply of intermediate web wound between said two rollers. The rollers extend beyond the sides of the cartridge and a section of the web between the rollers is disposed externally to the cartridge. The cartridge is removably mounted on a movable carriage having an essentially flat conductive peripheral support area supporting said external web section. Means is provided to transport the carriage thus moving the supported section of web in proper sequence from the imaging system or exposure station to the development and the transfer station on the copying machine and to then return the carriage to the imaging station in order to produce the desired copies. Drive means is provided on the machine which is coupled to the carriage at the exposure station and disposed upon the carriage as needed to change the section of web in producing subsequent copies, the web change being accomplished by the web being drawn from one roller in the cartridge while the used web is rewound on the other roller in the cartridge.

The above and added advantages of the present invention will be more apparent after reading the following detailed description which refers to the accompanying drawing wherein:

FIG. 1 is a schematic vertical sectional view illustrating an electrographic copying machine according to the present invention;

FIG. 2 is a perspective view of the web cartridge used in the electrographic copying machine of FIG. 1;

FIG. 3 is a vertical sectional view of the cartridge of FIG. 2;

FlG. 4 is a horizontal sectional view of the electrographic copying machine taken approximately along the line 4-4 of FIG. 1;

FIG. 5 is a fragmentary front elevational view of the copying machine, with the front cover removed and with parts in section;

FIG. 6 is a fragmentary rear elevational view of the machine as shown in FIG. 5; and

FIG. 7 is a fragmentary end view of the carriage of the copy machine withthe cartridge of FIG. 2 removed, and with parts in section for clarity.

Referring now to the drawing there is shown in FlG. l a schematic side elevational view of an electrographic copying machine utilizing the present invention, which is designated in its entirety by the numeral 10. The machine 211 has a generally rectangular frame having a transversely extending first side 11, an opposed parallel second side 12, a backside 13, a front side (not shown); a top 15, and a bottom plate 16 to which castors 17 for supporting the machine are mounted. The machine 10 is adapted to produce a copy of graphic intelligence via a process utilizing an intermediate web 21. In producing a copy, a section 22 of the intermediate web 21, properly registered and oriented at an imaging system 23, is exposed by the imaging system 23.

The imaging system 23 comprises a transparent imaging plate 24 upon which an original document to be copied is supported, a pair of mirrors 25 for folding the light path, suitable lamps 26 for illuminating the original document on the plate 24 and a lens system 27 for projecting the image of the graphic intelligence supported on the imaging plate 24 to the section 22 of intermediate web 21. The exposure registers a light image of the graphic intelligence from the original document onto a photoconductive coating on the registered section 22 of the intermediate web 21 and causes areas of differential conductivity in the coating on the intermediate web 21 which correspond to lighter and darker areas on the original document.

The intermediate web 21 utilized in this invention is contained in a cartridge 31 removably mounted on and defining with a carriage 32 an assembly which is mounted for reciprocable movement relative to the machine 10 along a straight path defined by a pair of fixed guide members or

rails

29 and 30 extending between the first side 11 and the second side 12 of the machine 10. The section 22 of web 21 is exposed while the carriage 32 is disposed under the imaging system 23 adjacent the second side 12 in what will be referred to as the home position. The section 22 of web 21 extends externally to the lighttight cartridge 31 and is supported externally to the cartridge 31 and on the upper peripheral surface of the assembly by a conductive platen 33. After exposure, accomplished by the operator energizing a suitable control circuit, the control circuit will energize moving means, which will hereinafter be described, to move the carriage 32 to carry the exposed section 22 of web 21 from the imaging system 23 past a development station 34.

As the carriage 32 passes under the development station 34 the switching circuit causes an electrical potential to be established between the development station 34 and the platen 33 on the carriage 32 to cause a dry, electrically conductive particulate material to be transferred to the image areas of the web section 22 in accordance with the "electropowder process described in French Pat. No. 1,456,993, issued Sept. I9, 1966. By the electropowder process, a photoresponsive sheet, for example, a photoconductive surface, is exposed to a light image without preliminary electrostatic charging to form a differentially conductive pattern corresponding to the light image and is then contacted with an electrically conductive developer powder while simultaneously a suitable electric potential is applied between a conductive support or backing for such imaged sheet and the powder applicator so that the imaged sheet is differentially coated with the powder corresponding to the conductive pattern thereon.

The powder applicator bearing the developer powder and the photoresponsive sheet are separated while maintaining the electrical potential between them, the electrical potential being discontinued after such separation. The resulting powder-coated photoresponsive sheet is then contacted with a receptor sheet while simultaneously being placed in a suitable electric field. The result is that a powder image of the graphic original is transferred from the photoresponsive sheet to the copy or receptor sheet and upon fusing the powder to the receptor sheet a copy of the graphic original is formed.

After the application of powder to the exposed section 22 of web 21, the carriage 32 continues toward the end of its path adjacent the side 11 of the machine 10 and subsequently reverses its direction of travel. On the return trip of the carriage 32 towards the side 12 a transfer station 35 is activated. A sheet-feeding mechanism (not shown) feeds a single sheet from a stack of copy sheets 36 which is supported on the copying machine 10. The single sheet is timed to contact the now leading edge of the exposed section 22 of web 21 and is pressed in contact with the successive portions of the coated section 22 of web 21 by the surface of a cylindrical roller 37 rotatably mounted between the backside 13 and the front side of the machine 10. Simultaneously there is applied an electrical potential between the platen 33 and the roller 37 to afford the transfer of the powder image from the intermediate web 21 to the copy sheet. The sheet is then transported by a suitable machine-mounted conveyor 38 into contact with a heated fusing roll 39 rotatably mounted on the copying machine 10 parallel with roller 37 so that the powder image will be fused to the copy sheet prior to the time it is discharged from the machine 10 as a completed copy into a receiving tray 40. The carriage 32 continues to its home position from the transfer station 35 at which point the switching circuit either causes the carriage 32 to recycle if further copies of the same graphic intelligence are desired, or causes the carriage 32 to stop if a sufficient quantity of copies have been produced from the exposed section 22 of intermediate web 21. After the carriage 32 has returned to the home position subsequent to producing the appropriate number of copies from the exposed section 22 of intermediate web 21, the web is advanced to change the section 22 by web-advancing means which will later be described in detail. The copying machine is then ready to be reactivated to copy a second original.

Referring now to FIGS. 2 and 3, the intermediate web cartridge 31 is generally lighttight and is formed by two mating shells 41 and 42 which define spaced generally cylindrical cavities with a narrow connecting and supporting area between the cavities. In the cartridge 31 are supported spools 43 upon which are wound a length of the intermediate web 21. The upper shell 41 is a molded member with transversely spaced side walls 44, end walls 45, and a top wall 46. The top wall 46 is formed with two generally semicylindrical or armate portions connected by a planar panel to define with the side and end walls 44 and 45 half of the cavities referred to above. An outwardly extending flange 47 surrounds the open side of the shell 41 which flange has a lip 48 formed about its periphery. The lip 48 and flange 47 define a seat for receiving a planar flange 49 of the lower shell 42. The lower shell 42 has opposed transversely spaced side walls 51 shaped to join with a bottom wall 53 to form two semicylindrical wall portions, and define the other half of the cavities. The flanges 47 and 49 and the

sidewalls

44 and 51 are formed with bearing surfaces to journal two parallel shafts 58 and 59 which carry axially spaced hubs to support the spools 43 upon which the strip of intermediate web material 21 is wound. The shafts 58 and 59 extend beyond the

sidewalls

44 and 51 and have ends attached to provide a half of a coupling 60 to mate with halves of couplings on the carriage 32 as will be hereinafter described to drive the shafts 58 and 59 from the carriage 32. The web 21 is threaded from one spool 43 to the other and passes out of the cartridge 31 through a slotted opening 61 located near the uppermost side of one end wall 45, over the top wall 36, and back into the cartridge onto the other spool 43 through a second slotted opening 61 located near the uppermost side of the other end wall 45. The slotted openings 61 are long narrow openings, and may be lined with a flocked material, to restrict ambient light from entering the cartridge and exposing the web in the cartridge during insertion of a cartridge or when the machine is opened for any purpose. The cartridge 31, comprising the shells 41 and 42 and the shafts 58 and 59, is symmetrical with respect to a vertical plane passing through the normally horizontal midpoint of the

sidewalls

44 and 51, and is symmetrical with respect to a vertical plane passing through the normally horizontal midpoints of the end walls 45. In the following description of the accompanying drawings, the assembly of the shaft 58 and its spool 43 will be termed a supply roller 63 and the shaft 59 and its spool 43 will be termed a take up roller 64, with the web being transferred form roller 63 to roller 64, however, the cartridge 31 can be mounted in the carriage 32 with either shaft to the right to permit the web to be wound from the right spool 43 or first roller to the left spool 43 or second roller in the carriage and then back by removing and tuming the cartridge 180 until the web is no longer usable.

As can be seen in FIGS. 1 and 5, the cartridge 31 with the supply of intermediate web 21 is received within the carriage 32 and is reciprocally movable therewith along the

rails

29 and 30 to produce a copy of a document. The carriage 32 comprises half couplings to mate the half couplings 60 on the shafts 58 and 59 and has means for driving the shafts 58 and 59 to advance the web from the supply roller 63 to the take up roller 64 during operation. As is best seen in FIG. 7 the carriage 32 includes the platen 33 to define the exposure plane for the web 21 which platen 33 is supported from a rectangular rear wall 66 of a frame of the carriage 32. The rear wall 66 supports a web advancing system and is supported by a pair of wheels 67 positioned .on the top of the rails 29. An inverted U- shaped beam 70 is cantilever mounted perpendicular to the bottom half of the wall 66 at essentially its horizontal center. At the end of the beam 70' is rotatably mounted a wheel 71 which runs on the rail 30 and in conjunction with the wheels 67 which run on the track 29 provides three point support for the carriage32 as it traverses the 29 and 30. Additional rollers 73 are provided to insure proper lateral and vertical positioning of the carriage 32 on the

tracks

29 and 30 thereby providing proper registration for the section 22 of intermediate web 21 exposed upon the platen 33.

The platen 33 is cantilever mounted perpendicular to the uppermost portion of wall 66. A transversely extending beam 75 extends from the wall 66 essentially the width of the platen 33 below the horizontalcenter of the platen 33, which beam 75 together with a web member 76 is intended to help support the platen 33.'1'he cartridge 31 fits between the

beams

70 and 75 with the upper half 41 of the cartridge 31 adjacent beam 75 and the cavities therein disposed on opposite sides of the

beams

70 and 75. Thus the carriage 32 is properly shaped to receive the cartridge 31 internally. Entrance of the cartridge 31 into the carriage 32 is obtained from the side oppositewall 66 through a pivoted gate 77. Rotatably mounted on the wall 66 of the carriage 32 are a half coupling 87 on a journaled stub shaft and a driven half coupling 88 on a drive shaft 89. The

half couplings

87 and 88 are centered properly for driving engagement with the half coupling 60 on one pair of adjacent ends of the rollers 63 and 64 when the cartridge 31 has been placed in the carriage 32.

The gate 77 is positioned opposite the wall 66 and is essentially a triangular framelike member, hinged at its lowermost point by a pin and slot arrangement 93 to the end of the beam 70. The gate 77 is mounted so as to swing down to a position where its normally vertical side is essentially parallel with the platen 33 to permit access to the cartridge 31 for insertion and removal thereof between the beam 70 and the beam 75 of the carriage 32. The gate 77 may then be swung to a vertical position essentially parallel with the wall 66 of the carriage 32 to enclose the cartridge 31 within the carriage 32. A pair of pins 91 are provided to accurately locate the gate 77 with respect to the rear wall 66 of the carriage 32 and thereby to position two half couplings 94 joumaled on the gate 77 by stub shafts to engage the half couplings 60 on the end of shafts 58 and 59 of the cartridge 31 opposite the half couplings 60 engaging the

hubs

87 and 88 on the wall 66 so that the rollers 63 and 64 of the cartridge 31 will be aligned parallel with two

guide rollers

97 and 98 on the carriage 32.

A hand wheel 95 affixed to a threaded shaft 96 rotatably mounted on the gate 77 secures the gate 77 to the beam 75 of the carriage 32. The wheel 95 is generally centered on the gate and the threaded shaft is designed to engage a taped hole in the end of the beam 75 to hold the gate in place and maintain contact between the

half couplings

87, 88 and 94 and the half couplings 60 on the cartridge shafts 58 and 59 when the gate 77 is in an upright position.

A telescoping support (not shown) may be mounted on the beam 70 to assist in supporting the cartridge 31 for movement along the beam 70 toward the rear wall 66. As the cartridge 31 reaches the wall 66 supported by the telescoping support, the half couplings 60 on the leading side of the cartridge 31 engage the

couplings

87 and 88. The telescoping support continues to support the ends of the shafts 58 and 59 adjacent the gate 77 until the gate 77 is attached in its vertical position, at which time the half couplings 94 contact the half couplings 60 to support the shafts 58 and 59, and thereby the cartridge 31.

The first guide roller 97 defines part of the path for the web between the supply roller 63 in the cartridge 31 and the platen 33. The roller is not readily rotatable to provide tension for restricting wrinkles from appearing in the web 21 as it is drawn across the platen 33. Rotation of the roller 97 is retarded by friction devices (not shown) incorporated in the journals mounting the roller 97. The roller 97 is mounted on transver' sely spaced ears extending from the end of the platen 33 adjacent the first roller 63 and is located so that the uppermost surface of the platen 33 is in a plane tangent to its periphery.

The second guide roller 98, attached to a shaft 99 defines part of the path of the web 21 between the platen 33 and the takeup roller 64 in the cartridge 31 and provides drivingcontact with the web 21 to pull it across the platen 33 when the web is wound from the supply roller 63 to the takeup roller 64. The roller 98 is rotatably mounted on transversely spaced ears extending from the end of the platen 33 adjacent the takeup roller 64, and is positioned so that the plane of the uppermost surface of the platen is tangent to the periphery of the roller 98.

As through cleaning of the particulate material from the intermediate web 21 after each exposure will prolong the useful life of the web 21, a cleaning device (not shown) may be attached to the machine 10 which will be located adjacent roller 98 when the carriage 32 is in its home" position. The aforementioned cleaning device will remove the last traces of the dry electrically conductive particulate material from the intermediate web 21 as the web 21 passes over the surface of roller 98 prior to being wound on the takeup roller 64.

The roller 98 is driven so that the web 21 may be advanced from the supply roller 63 to the take up roller 64, thereby changing the section 22 of web 21 exposed on the platen. The roller 98 is driven from the shaft 99 to which is attached adjacent the rear of wall 66 a sprocket 101. Sprocket 101 is connected by a suitable roller chain 102 to a drive sprocket 103 driven from a gearbox assembly 104. The gearbox assembly 104 is mounted on the rear of the wall 66 opposite the half coupling 88. The gearbox assembly 104 is also coupled to the drive shaft 89 mounting the half coupling 88 and thereby drives the takeup roller 64 through a frictional drive or slip clutch mechanism (not shown) within the gearbox assembly 104. Sufficient torque at the proper rate is thereby provided to the takeup roller 64 to wind the web 21 advanced over the platen 33 by the roller 98, however, the frictional driving contact in the gearbox assembly 104 will slip before a torque is transmitted to the takeup roller 64 which is sufficient to pull the web 21 across the driving surface of roller 98.

As can be seen in FIGS. 4 and 6, the gearbox assembly 104 receives its driving torque through a torque coupling 105 from the web advancing drive means fixed on the machine frame. The drive coupling for the gearbox 104 is mounted on a shaft 107 extending from the side of the gearbox assembly 104. The coupling 105 may be driven as needed in producing copies when the carriage 32 is located in its home position by the web-advancing driving means generally designated 106. The drive coupling 105 may comprise a collar having diametrical slots to receive a shaft 108 having a transverse pin pressed therethrough which shaft 108 is the driving member for the driving means 106. Driving contact between the collar and pin is facilitated by the coupling 105 being axially movable and urged by a spring 110 into proper driving contact with the pin in the driving shaft 103 such that after the shaft 108 is rotated by the driving means 106 the coupling 111 5 is positioned so that the notch therein will make driving contact or engagement with the pin.

The driving shaft 108, which is thus part of the driving means 166 for advancing the section 22 of web 21 on the platen 33 as needed in the copying process, is journaled on a bracket 109 and is driven through a pulley 111 attached thereto and a suitable belt or chain 112 driven by a motor 113 mounted on the bracket 1119, which bracket 109 is attached to the bottom plate 16.

A cartridge 31 containing the intermediate web 21 is inserted over the gate 77 when it is lowered, and over the beam 70 under the platen 33 so that the beam 75 fits between the cartridge cavities and so that the

half couplings

87 and 88 on the rear wall 66 engage the half couplings 60 on the ends of the shafts 58 and 59. While the cartridge 31 is being inserted, the section of web exposed externally to the cartridge 31 is slightly larger and is directed over the

rollers

97 and 98 and the platen 33. After the cartridge 31 is in position within the carriage 32 the roller 63 may be rotated slightly to take up some slack in the web and the gate 77 is raised to its vertical position. The handwheel 95 is rotated so that the threaded shaft 96 engages the end of the beam 75 which brings the half couplings 94, in contact with the half couplings 61) which are attached to the rollers 63 and 64. The shell of the cartridge 31 is then supported by the journals for the rollers 63 and 64 which rollers are now supported through the couplings by the backwall 66 and the gate 77. When the carriage 32 is in its home" position and driving torque is supplied by the motor 113 through the coupling 1115 and the gear box assembly 104, the roller 96 applies frictional driving force to the intermediate web 21 causing it to be transferred from the supply roller 63 to the take up roller 64. Appropriate tension in the intermediate web 21 to provide a wrinkle-free section on the platen 33 is provided by the restraining torque applied to the roller 97 from the friction brake assemblies incorporated in its mounting. To prevent excessive rotation of the supply roller 63 a friction brake also operates on the shaft journaling the half coupling 87 which engages the half couplings 61) on the supply roller 63. In order to provide appropriate takeup tension for the web 21 being wrapped on the takeup roller 64, the gearbox assembly 104 provides frictional driving contact to the shaft 89 supporting half coupling 88 which drives the takeup roller 64 at a speed designed to produce a linear speed of intermediate take up greater than the linear speed of intermediate web 21 advance provided by the driven roller 98. The frictional driving mechanism rotating the take up roller 64 is designed to produce a maximum torque insufficient to overcome the friction between the driven roller 98 and the intermediate web 21. For this reason, slippage occurs in the frictional driving mechanism turning the take up roller 64 while still providing adequate take up tension throughout the varying angular speed required of the roller 64 while it accumulates the intermediate web 21. By this advancing system the intermediate web 211 may be advanced when needed to produce the desired variety or quantity of copies with this electrographic copying machine 10.

Drive means are provided for causing the carriage 32 to traverse the

rails

29 and 30 so that the section 22 of intermediate web 21 supported on the platen 33 may be moved from the imaging system 23 past the developing section 34 and returned via the transfer section 35 to produce a print. The drive means comprises a bar 115 pivotally attached at one end to a point on the underside of the beam 70 in a vertical longitudinal plane parallel with the wall 66 through the center of gravity of the carriage 32 when it has a cartridge 31 mounted therein. The other end of the bar 115 is rotatably attached to and is towed or pushed by a link 116 on an endless tracking member or roller chain 117 as the chain 117 is driven around spaced supporting sprocket wheels 118 and 119. The roller chain 117 travels a path or track parallel to the bottom plate 16, which path is defined by the idler sprocket 118 and the chain drive sprocket 119 rotatably mounted on the upper surface of the bottom plate 16. The track having two straight legs connecting tangential points on the opposite sides of the sprockets and arcuate sections joining the legs about the sprockets. The sprockets 118 and 119 are positioned so that the straight lengths of the chain 117 between the sprockets 118 and 119 are parallel with the

rails

29 and 30 travelled by the carriage 32, and so that the axis of the sprockets 118 and 119 fall in a vertical plane through the center of gravity of the carriage 32 with a cartridge 31 installed. The sprocket 119 is properly positioned so that when the link 116 is on the periphery of sprocket 119 in a plane through the axis of the sprockets 118 and 119, the bar will position the carriage 32 under the imaging system 23. As the sprocket 119 is driven counterclockwise as viewed in FIG. 4, the carriage will be drawn by the bar 115 along the

rails

29 and 30 toward the first side 11 past the development station 34 to the transfer station 35. After the link 116 on the chain 117 has traversed the sprocket 118 located near the side 11 cf the machine 10, the carriage will be pushed by the bar 115 through the transfer station 35 and returned to the imaging system 23.

A guide member 123 comprising two U-shaped tracks attached to the bottom plate 16 supports and guides the two lengths of roller chain 117 extending between the sprockets 118 and 119 so that the link 116 will maintain a straight line path as it tows or pushes the carriage 32 via the bar 115.

To provide the driving force to the chain 117 to move the carriage 32, a sprocket 128, attached to the shalt-supporting sprocket 119 between the sprocket 119 and the bottom plate 16 of the copying machine 10 is driven by a chain 129 from a drive sprocket 131 attached to a suitably gear-reduced motor 132 mounted on a bracket 134 which is attached to the bottom plate 16.

in order that the carriage 32 may be exactly positioned under the imaging system 23 for a new exposure the on the web 21 after the carriage 32 has traversed the

rails

29 and 30 making prior copies, a low-speed positioning system is provided. The armature of the motor 132 extends externally to the motor 132 and is attached through s sprocket 136, a chain 137 and a sprocket 138 to a low-speed positioning motor 140 attached to the bracket 134. When the carriage 32 is to be moved under the imaging system 23, the circuit disconnects the power to motor 132 with the carriage 32 in a position slightly removed from a proper home" position. The circuit then activates the positioning motor 140 which slowly drives the rotor of motor 132, thereby driving the chain 117 to exactly position the carriage 31 under the imaging system 23, this position being indicated to the circuit by indicating switches mounted on the machine 10.

The drive means for the carriage 32 are designed to minimize the inertial forces which act upon the carriage 32 as it conveys the exposed section 22 of web 21 upon its platen 33 from the imaging system 23 past the developing station 34 and then returns past the transfer station 35. With the carriage in its home" position under the imaging system 23, the link 116 which is attached to the carriage 32 by the bar 115 is located on the periphery of the sprocket 119 at the point closest the second side of the machine 10. When the motor 132 is activated to cause the carriage 32 to traverse the

rails

29 and 36, it drives the chain 117 between the sprockets 118 and 119, thereby causing the link 116 to start on its path around sprocket 119 towing the carriage 32 by the bar 115. The immediate starting of the link 116 along its path at essentially full speed will not. cause an immediate maximum velocity of the carriage 32 toward the first side 11 of the machine 10, because of the gradual increase in the component of velocity of the link 116 in the direction towards the first side 11 as the link 116 is moved along its path about a 90 degree segment of the circumference of the sprocket 119. This relatively gradual acceleration pattern is again repeated at the sprocket 118 where the link 116 and the carriage 32 are decelerated to zero velocity towards the first side 11 of the machine 10 while the link 116 travels the first 90 of its path around the sprocket 118 and then the carriage 32 is gradually accelerated along the tracks towards the second side 12 while the link 116 travels the second 90 segment of its path around sprocket 118. The affect of this gradual acceleration and deceleration of the carriage 32 is to minimize the inertial forces acting throughout the traversing of the carriage 32, thereby permitting more rapid traversing of the carriage 32 upon the machine 10, which in turn permits a higher rate of copy production with a minimum of abuse to the copy machine 10.

Having thus described the present invention what is claimed 1. A copying machine adapted to produce a copy of graphic intelligence via an intermediate web material, said machine comprising imaging" nieansfor exposing a said intermediate web material, developing means for developing an image of said graphic intelligence on said web material, and transfer means for transferring the image on the web material to a sheet to produce a visible image of said graphic intelligence on said sheet, the improvement comprising:

, a carriage assembly mounted on said machine,

a cartridge assembly removably mounted on said carriage assembly for storing a supply of web material, said cartridge assembly comprising: ashell, o a first roller mounted rotatably in said shell, a second roller rotatably mounted in said shell parallel to said firstroller, and 1 a strip of web m'aterialbeing attached at its respective ends to, and extending between, said first roller and said second roller with respective portions of said web being wound on said first roller and on said second roller, and with a section of at least one surface of said web material extending between said wound portions being exposed externally to said shell, means mounted on said carriage assembly for moving said web material between said first roller and said second roller thereby changing the section of web material exposed externally to said cartridge, and

moving means mounted on said machine for providing relative movement between said exposed section of web material on said cartridge and at least said developing means and said transfer means.

2. A copying machine according to claim 1 wherein said imaging means, said developing means and said transfer means are attached in fixed relationship to said machine and said moving means comprises fixed guides and means for mounting said carriage assembly for movement along said fixed guides so that a said section of intermediate web material exposed externally to said cartridge is brought in proper sequential disposure with said imaging means, said developing means and said transfer means.

3. A copying machine according to claim 2 wherein said fixed guides and said means mounting said carriage assembly afford straight line reciprocal movement along a path which when traversed places the section of web material exposed externally to said cartridge in sequential disposure with said imaging means, said developing means and said transfer means.

4. A copying machine according to claim 3 wherein said fixed guides are a pair of parallel rails mounted on said copying machine.

5. A copying machine according to claim 3 wherein said moving means comprises:

an endless tracking member,

a track attached to said machine, said track having two legs positioned essentially parallel to the path traversed by said carriage assembly with the adjacent ends of said two legs of said track joined by an are shaped track section having a radius equal to one-half the separating distance of said two legs, said track supporting and restraining said endless tracking member along said track,

a link rotatably attached between one point on said tracking member and said carriage assemblg, the point of attachment between said link and sat carnage assembly being positioned at a point essentially half the distance between said track legs, and a driving means for moving said tracking member along said track thereby moving said carriage assembly along the straight line path traversed by said carriage assembly, said arcuate track being traveled by said link attaching point on said tracking member in changing directions, thus serving to minimize the rate of acceleration and deceleration of the carriage assembly in the direction parallel with the line of travel of said carriage assembly during the time the direction of travel of said carriage assembly is reversed. 6. A copying machine according to claim 3 wherein said web moving means mounted on said carriage assembly for moving said web material between said first roller and said second roller comprises a motor attached to said copying machine which drives a coupling which couples with said web moving means on said carriage assembly when said carriage assembly is positioned under said imaging means to move said web material between said first roller and said second roller as required in the operation of said copying machine.

7. A copying machine according to claim 1 wherein said carriage assembly comprises a frame member, said frame member comprising a planar web support for positioning a section of said web material extending between said rollers, a main rectangular support wall supporting said web support, a movable gate opposite said support wall affording insertion of said cartridge assembly, and support means affording movement of said carriage assembly relative to said developing means.

Patent No. 3, 17,124 Da ed November 2, 1971 Inventor) Orville C. Haugen and Emil J. Kvaal It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 1, change "minimizer" to minimized Column 3, line 2, change "20" to lO and line &9, change "tropowder" to tro-powder Column 5, line 21, change "rails" to rail line '27, after "the" second occurrence add rails line 99, after "the" second occurrence chan e "tracks" to rails and line &7, change "coupling to couplings Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDwARD M.FLETCI-IER,JR. ROBERT GOITSCHALK Attestzmg Officer Commissioner of Patents ORM PO-10 0l USCOMM-DC B0375-P69 (I U S GOVERNMENT PRINTING OFFICE l9? O-3GG33A

Claims

1. A copying machine adapted to produce a copy of graphic intelligence via an intermediate web material, said machine comprising imaging means for exposing a said intermediate web material, developing means for developing an image of said graphic intelligence on said web material, and transfer means for transferring the image on the web material to a sheet to produce a visible image of said graphic intelligence on said sheet, the improvement comprising: a carriage assembly mounted on said machine, a cartridge assembly removably mounted on said carriage assembly for storing a supply of web material, said cartridge assembly comprising: a shell, a first roller mounted rotatably in said shell, a second roller rotatably mounted in said shell parallel to said first roller, and a strip of web material being attached at its respective ends to, and extending between, said first roller and said second roller with respective portions of said web being wound on said first roller and on said second roller, and with a section of at least one surface of said web material extending between said wound portions being exposed externally to said shell, means mounted on said carriage assembly for moving said web material between said first roller and said second roller thereby changing the section of web material exposed externally to said cartridge, and moving means mounted on said machine for providing relative movement between said exposed section of web material on said cartridge and at least said developing means and said transfer means.

5. A copying machine according to claim 3 wherein said moving means comprises: an endless tracking member, a track attached to said machine, said track having two legs positioned essentially parallel to the path traversed by said carriage assembly with the adjacent ends of said two legs of said track joined by an arc shaped track section having a radius equal to one-half the separating distance of said two legs, said track supporting and restraining said endless tracking member along said track, a link rotatably attached between one point on said tracking member and said carriage assembly, the point of attachment between said link and said carriage assembly being positioned at a point essentially half the distance between said track legs, and a driving means for moving said tracking member along said track thereby moving said carriage assembly along the straight line path traversed by said carriage assembly, said arcuate track being traveled by said link attaching point on said tracking member in changing directions, thus serving to minimize the rate of acceleration and deceleration of the carriage assembly in the direction parallel with the line of travel of said carriage assembly during the time the direction of travel of said carriage assembly is reversed.

6. A copying machine according to claim 3 wherein said web moving means mounted on said carriage assembly for moving said web material between said first roller and said second roller comprises a motor attached to said copying machine which drives a coupling which couples with said web moving means on said carriage assembly when said carriage assembly is positioned under said imaging means to move said web material between said first roller and said second roller as required in the operation of said copying machine.