Systems and methods herein generally relate to apparatuses that move sheets along sheet paths and more particularly to devices useful at intersections of sheet paths.
The more compact that a sheet transport device can be made produces advantages including weight reduction, lower cost, reduced area requirements, etc. In one example, some sheet transport devices handle oversized and overlength sheets. Such devices end up having an increased size that can decrease user satisfaction.
Various apparatuses herein include, among other components, a pair of opposing drive rollers, a pair of opposing idle rollers, and a rotatable support operatively connected to the axles of the idle rollers. Axles of the drive rollers and the idle rollers are positioned along a circle. The axles of the drive rollers and the idle rollers alternate along the circle. Also, rotation of the rotatable support moves the idle rollers along the circle until the idle rollers contact the drive rollers. Each of the idle rollers is positioned by the rotatable support to only contact a single drive roller at a time.
Additional apparatuses herein include, among other components, a frame, drive rollers operatively connected to the frame, a rotatable support operatively connected to the frame, idle rollers operatively connected to the rotatable support. The drive rollers and the idle rollers lie in the same plane. A pivot axis of the rotatable support is centered between axles of the drive rollers and is also centered between axles of the idle rollers. The axles of the drive rollers are in a fixed position relative to the frame and the axles of the idle rollers move relative to the drive rollers as the rotatable support rotates.
Additional embodiments herein include a sheet transport device. Such a device includes, among other components, a frame, sheet transport paths operatively connected to the frame, and a path intersection nip driver positioned at an intersection of two of the sheet transport paths.
The path intersection nip driver includes, among other components, drive rollers operatively connected to the frame, a rotatable support operatively connected to the frame, and idle rollers operatively connected to the rotatable support. The drive rollers and the idle rollers lie in the same plane. A pivot axis of the rotatable support is centered between axles of the drive rollers and centered between axles of the idle rollers. The axles of the drive rollers are in a fixed position relative to the frame and the axles of the idle rollers move relative to the drive rollers as the rotatable support rotates.
More specifically, rotation of the rotatable support in a first direction relative to the frame causes a first idle roller to contact a first drive roller and a second idle roller to contact a second drive roller. Conversely, rotation of the rotatable support in a second direction (opposite the first direction) causes the first idle roller to contact the second drive roller and the second idle roller to contact the first drive roller. The first idle roller spins in opposite directions when contacting either the first drive roller or the second drive roller, and the second idle roller similarly spins in opposite directions when contacting either the first drive roller or the second drive roller.
Also, contact between the first idle roller and the first drive roller forms a first drive nip. Contact between the second idle roller and the second drive roller forms a second drive nip. Contact between the first idle roller and the second drive roller forms a third drive nip. Contact between the second idle roller and the first drive roller forms a fourth drive nip. The first drive nip and the second drive nip form a first sheet path and the third drive nip and the fourth drive nip form a second sheet path. The first sheet path intersects the second sheet path. Additionally, the pivot axis of the rotatable support is aligned with a sheet path intersection location where the first sheet path intersects the second sheet path.
Such devices also include at least one drive motor operatively connected to the frame. The drive rollers are connected to the drive motor to continuously rotate in opposite directions. Also included is a rotation motor operatively connected to the frame. The rotatable support is connected to the rotation motor to pivot about the pivot axis upon operation of the rotation motor. The rotation motor is adapted to alternatively rotate the rotatable support in either a clockwise direction or a counter-clockwise direction.
These and other features are described in, or are apparent from, the following detailed description.
Various exemplary systems and methods are described in detail below, with reference to the attached drawings, in which:
As mentioned above, reducing the size of a sheet transport device can produce a number of advantages, including weight reduction, lower cost, reduced area requirements, etc. Some devices temporarily extend sheet paths outside their normal locations when accommodating extra-large sheets. However, sheet paths can be made to curve within sheet transport devices to increase the length of the sheet path and correspondingly increase the sheet size that can be accommodated without increasing the exterior size of the sheet transport devices.
Additionally, utilizing intersecting paper paths helps increase the sheet size that can be accommodated without increasing overall device size. One issue with some sheet intersection devices is that they can be unreliable and can result in an unacceptably high rate of sheet jams. Alternative intersection designs can reduce the probability of sheet jams; however, such devices are more complex, which renders such complex devices more expensive and more vulnerable to component failure.
In view of such issues, the systems and methods herein provide sheet path intersection devices that use a simplified structure with a very low sheet jam rate to promote a compact structure. Some devices herein use two fixed-position drive shafts connected to drive rollers in combination with two movable idler shafts connected to idler rollers. The idler shafts are joined together so that they pivot about the center of the sheet intersection. An actuator moves the idler shafts into multiple positions, which allows two drive nips to be formed to drive sheets through the intersection in either of two directions. This provides a simplified, compact architecture that easily switches between different sheet paths without sheet jams.
Sheets directed to the sheet reversal path 335 are generally sheets that have received printing or other processing on one side and such sheets pass into a long curved reversal path portion 337. The sheets stop and reverse direction and are directed to an exit path 339 and out a duplex exit 341. The process of reversing the sheets and directing the sheets along the exit path 339 flips the sheets. The duplexed (flipped) sheets exiting the duplex exit 341 are returned to the printer to allow printing on the other side of the sheets.
For certain applications, for instance ballot printing, it is desired to print in duplex mode on sheets significantly longer than standard (e.g., 14 inches long or longer). The reversal path portion 337 and exit path 339 shown in
In order to accommodate for the added length of the reversal path portion 337 and exit path 339 without increasing the overall dimensions of the sheet transport device 336 or using exterior sheet path extensions, the sheet paths 333 and 339 intersect at the path intersection nip driver 100. As noted above, the path intersection nip driver 100 uses two fixed-position drive shafts connected to drive rollers in combination with two movable idler shafts connected to idler rollers. The idler shafts are joined together so that they pivot about the center of the intersection. An actuator moves the idler shafts into multiple positions, which allows two drive nips to be formed to drive sheets through the intersection in either of two directions.
While driven rollers are shown in the examples below, with path intersection nips herein, the four rollers shown at the intersection can all be idler rolls, such that they freewheel (freely spin on their axles) when a sheet of paper driven by an upstream nip driver directs a sheet through the intersection. In some examples discussed below, two of the rollers are driven at a commanded velocity to ensure a continuous drive force acting on the sheet throughout its passage through the path intersection.
Therefore,
As noted above, the structure also includes a rotation motor 130 operatively connected to the frame 302. The rotatable support 150 is connected to the rotation motor 130 to pivot about the pivot axis 152 upon operation of the rotation motor 130. The rotation motor 130 is adapted to alternatively rotate the rotatable support 150 in either a clockwise direction or a counter-clockwise direction.
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In the example illustrated in
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The idle shafts 146, 148 cause all the idle rollers 120, 120A, 120B, 122, 122A, 122B to move as the two rotatable supports 150 rotate. One of the rotatable supports 150 is connected to the rotation motor 130 through the rotation shaft 140 for the rotation. Each of the idle shafts 146, 148 contains at least two of the idle rollers 120 or 122. Similarly, each of the drive shafts 142, 144 contains at least two of the drive rollers 110 or 112.
In the structure shown in
As noted above, such devices also include at least one drive motor 132, 134 operatively connected to the frame 302. In the examples above, the drive rollers 110, 112 are connected to two drive motors 132, 134. However, as shown in
The above examples show how the idler assembly can be switched between two positions to provide the appropriate drive force to sheets traveling approximately perpendicular to each other (e.g., either vertically or horizontally). The idler assembly actuator can bias the idler assembly either clockwise or counter-clockwise, as needed. It is also possible to arrange the actuator to provide a third ‘neutral’ position in which there are no nips engaged. This could be used for improved jam clearance, for example. Therefore, these structures present a simple architecture to provide selectable drive force to sheets passing through a 4-way intersection and this enables highly compact and complex paper paths to be maintained within a compact exterior.
As noted above, these devices include (among other components) what is generically referred to herein as a “frame” 302. The frame 302 can comprise many different components of the apparatus, which are elements of the apparatus and which are directly or indirectly connected to each other. Thus, the frame herein can include any or all of the various elements that physically support the enumerated components discussed herein. In the attached drawings, identification numeral 302 is used to indicate the different items that can be considered to be this generically defined “frame.” Relative to the device exterior, the frame is in a fixed location (even though many of the attached components move, rotate, etc., relative to the frame 302) and therefore all the following components are directly or indirectly connected to the frame 302 in some way.
The input/output device 314 is used for communications to and from the computerized device 304 and comprises a wired device or wireless device (of any form, whether currently known or developed in the future). The tangible processor 324 controls the various actions of the computerized device. A non-transitory, tangible, computer storage medium device 310 (which can be optical, magnetic, capacitor based, etc., and is different from a transitory signal) is readable by the tangible processor 324 and stores instructions that the tangible processor 324 executes to allow the computerized device to perform its various functions, such as those described herein. Thus, as shown in
The printing device 304 includes at least one marking device (printing engine(s)) 340 operatively connected to a specialized image processor 324 (that is different from a general purpose computer because it is specialized for processing image data), a media path 336 positioned to supply continuous media or sheets of media from a sheet supply 330 to the marking device(s) 340, etc. After receiving various markings from the printing engine(s) 340, the sheets of media can optionally pass to a finisher 334 which can fold, staple, sort, etc., the various printed sheets. Also, the printing device 304 can include at least one accessory functional component (such as a scanner/document handler 332 (automatic document feeder (ADF)), etc.) that also operate on the power supplied from the external power source 320 (through the power supply 318).
The one or more printing engines 340 are intended to illustrate any marking device that applies a marking material (toner, inks, etc.) to continuous media or sheets of media, whether currently known or developed in the future and can include, for example, devices that use an ink jet imaging system, as shown in
More specifically,
The media is propelled by a sheet transport 362 that can include a variety of motors rotating one or more rollers. For duplex operations, an inverter 366 may be used to flip the sheet over to present a second side of the media to the printheads 342A-342D.
The media conditioner 360 includes, for example, a pre-heater. The pre-heater brings the media to an initial predetermined temperature that is selected for desired image characteristics corresponding to the type of media being printed as well as the type, colors, and number of inks being used. The pre-heater may use contact, radiant, conductive, or convective heat to bring the media to a target preheat temperature.
The media is transported through a printing station that includes a series of color printheads 342A-342D, each color unit effectively extending across the width of the media and being able to place ink directly (i.e., without use of an intermediate or offset member) onto the moving media. As is generally familiar, each of the printheads may eject a single color of ink, one for each of the colors typically used in color printing, namely, cyan, magenta, yellow, and black (CMYK). A controller 324 generates timing signals for actuating the ink jet ejectors in the printheads 342A-342D in synchronization with the passage of the media to enable the four colors to be ejected with a reliable degree of accuracy for registration of the differently colored patterns to form four primary-color images on the media. The ink jet ejectors are actuated by the firing signals to correspond to image data processed by the controller 324 that may be transmitted to the printer, generated by a scanner (not shown) that is a component of the printer, or otherwise generated and delivered to the printer. In various possible embodiments, a color unit for each primary color may include one or more printheads; multiple printheads in a color unit may be formed into a single row or multiple row array; printheads of a multiple row array may be staggered; a printhead may print more than one color; or the printheads or portions of a color unit may be mounted movably in a direction transverse to the process direction, such as for spot-color applications and the like.
Each of color printheads 342A-342D may include at least one actuator configured to adjust the printheads in each of the printhead modules in the cross-process direction across the media web. In a typical embodiment, each motor is an electromechanical device such as a stepper motor or the like. In a practical embodiment, a print bar actuator is connected to a print bar containing two or more printheads and is configured to reposition the print bar by sliding the print bar along the cross-process axle of the media web. In alternative embodiments, an actuator system may be used that does not physically move the printheads but redirects the image data to different ejectors in each head to change head position.
The printer may use liquid ink or “phase-change ink,” by which is meant that the ink is substantially solid at room temperature and substantially liquid when heated to a phase change ink melting temperature for jetting onto the imaging receiving surface. The phase change ink melting temperature may be any temperature that is capable of melting solid phase change ink into liquid or molten form. As used herein, liquid ink refers to melted solid ink, heated gel ink, or other known forms of ink, such as aqueous inks, ink emulsions, ink suspensions, ink solutions, or the like.
Associated with each color unit is a backing member, typically in the form of a bar or roll, which is arranged substantially opposite the color unit on the back side of the media. Each backing member is used to position the media at a predetermined distance from the printheads opposite the backing member. Each backing member may be configured to emit thermal energy to heat the media to a predetermined temperature.
Following the printing zone along the media path are one or more “mid-heaters” 344. A mid-heater 344 may use contact, radiant, conductive, and/or convective heat to control a temperature of the media and particularly to bring the media to a temperature suitable for desired properties when passing through the spreader 346. A fixing assembly in the form of the “spreader” 346 is configured to apply heat and/or pressure to the media to fix the images to the media. The function of the spreader 346 is to take what are essentially droplets, strings of droplets, or lines of ink on the sheet and smear them out by pressure and, in some systems, heat, so that spaces between adjacent drops are filled and image solids become uniform. The spreader 346 may include rollers, such as image-side roller 352 and pressure roller 350, to apply heat and pressure to the media, either of which can include heating elements, such as heating elements 348, to bring the media to a predetermined temperature. The spreader 346 may also include a cleaning/oiling station 354 associated with image-side roller 352. The station 354 cleans and/or applies a layer of some release agent or other material to the roller surface. A coating station 364 applies a clear ink to the printed media to modify the gloss and/or to help protect the printed media from smearing or other environmental degradation following removal from the printer.
Operation and control of the various subsystems, components and functions of the imaging system are performed with the aid of the controller 324. The controller 324 may be implemented with general or specialized programmable processors that execute programmed instructions. The controller 324 may be operatively coupled to the print bar and printhead actuators of color printheads 342A-342D in order to adjust the position of the print bars and printheads along the cross-process axle of the media web. In particular, the controller may be operable to shift one or more, or all, of the color units laterally or transverse to the process direction.
The imaging system may also include an optical imaging system 356 that is configured in a manner similar to that for creating the image to be transferred to the web. The optical imaging system is configured to detect, for example, the presence, intensity, and/or location of ink drops jetted onto the receiving member by the ink jets of the printhead assembly. The imaging system may incorporate a variety of light sources capable of illuminating the printed web sufficient to detect printing errors that may be attributable to a faulty or defective ink jet or printhead. The imaging system 356 further includes an array of light detectors or optical sensors that sense the image reflected from the printed web prior to discharge. The controller 324 analyzes the information from the imaging system 356 to determine, among other things, whether a failure or an ink jet or printhead has occurred. The location of the defective printing element is identified and made available to the maintenance technician during a diagnosis procedure. The controller 324 may also use the data obtained from the imaging system 356 to adjust the registration of the color units such as by moving a color unit or one or more printheads. This image data may also be used for color control.
The pretreatment unit 420 includes at least one pretreatment device 422 and transport belt 424. The pretreatment unit 420 receives the media sheets from the media supply 410 and transports the media sheets in a process direction (block arrows in
The printing unit 430 includes at least one marking unit transport belt 432 that receives the media sheets from the pretreatment unit 420 or the media supply 410 and transports the media sheets through the printing unit 430. The printing unit 430 further includes at least one printhead (labeled CMYK in
The dryer 440 includes a heater 442 and a vacuum drying belt 444 that receives the media sheets from the printing unit 430. A vacuum plenum 446 connects to a vacuum blower or the plumbing that is connected to a vacuum blower at one side in the cross-process direction. The sheet stacker 450 receives and stacks the printed sheets 452.
While
The print media is then transported by the sheet output transport 336 to output trays or a multi-function finishing station 334 performing different desired actions, such as stapling, hole-punching and C or Z-folding, a modular booklet maker, etc., although those ordinarily skilled in the art would understand that the finisher/output tray 334 could comprise any functional unit.
As would be understood by those ordinarily skilled in the art, the printing devices shown here are only examples and the systems and methods herein are equally applicable to other types of printing devices that may include fewer components or more components. For example, while a limited number of printing engines and paper paths are illustrated, those ordinarily skilled in the art would understand that many more paper paths and additional printing engines could be included within any printing device used with systems and methods herein.
Many computerized devices are discussed above. Computerized devices that include chip-based central processing units (CPU's), input/output devices (including graphic user interfaces (GUI), memories, comparators, tangible processors, etc.) are well-known and readily available devices produced by manufacturers such as Dell Computers, Round Rock TX, USA and Apple Computer Co., Cupertino CA, USA. Such computerized devices commonly include input/output devices, power supplies, tangible processors, electronic storage memories, wiring, etc., the details of which are omitted herefrom to allow the reader to focus on the salient aspects of the systems and methods described herein. Similarly, printers, copiers, scanners and other similar peripheral equipment are available from Xerox Corporation, Norwalk, CT, USA and the details of such devices are not discussed herein for purposes of brevity and reader focus.
The terms printer or printing device as used herein encompasses any apparatus, such as a digital copier, bookmaking machine, facsimile machine, multi-function machine, etc., which performs a print outputting function for any purpose. The details of printers, printing engines, etc., are well-known and are not described in detail herein to keep this disclosure focused on the salient features presented. The systems and methods herein can encompass systems and methods that print in color, monochrome, or handle color or monochrome image data. All foregoing systems and methods are specifically applicable to electrostatographic and/or xerographic machines and/or processes.
In addition, terms such as “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “upper”, “lower”, “under”, “below”, “underlying”, “over”, “overlying”, “parallel”, “perpendicular”, etc., used herein are understood to be relative locations as they are oriented and illustrated in the drawings (unless otherwise indicated). Terms such as “touching”, “on”, “in direct contact”, “abutting”, “directly adjacent to”, etc., mean that at least one element physically contacts another element (without other elements separating the described elements). Further, the terms automated or automatically mean that once a process is started (by a machine or a user), one or more machines perform the process without further input from any user. Additionally, terms such as “adapted to” mean that a device is specifically designed to have specialized internal or external components that automatically perform a specific operation or function at a specific point in the processing described herein, where such specialized components are physically shaped and positioned to perform the specified operation/function at the processing point indicated herein (potentially without any operator input or action). In the drawings herein, the same identification numeral identifies the same or similar item.
While some exemplary structures are illustrated in the attached drawings, those ordinarily skilled in the art would understand that the drawings are simplified schematic illustrations and that the claims presented below encompass many more features that are not illustrated (or potentially many less) but that are commonly utilized with such devices and systems. Therefore, Applicants do not intend for the claims presented below to be limited by the attached drawings, but instead the attached drawings are merely provided to illustrate a few ways in which the claimed features can be implemented.
It will be appreciated that the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. Unless specifically defined in a specific claim itself, steps or components of the systems and methods herein cannot be implied or imported from any above example as limitations to any particular order, number, position, size, shape, angle, color, or material.