Patent Publication Number: US-6666399-B2

Title: System for transfer and inversion of a continuous web substrate between printing and other devices

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on a Provisional Patent Application No. 60/299,014, filed Jun. 18, 2001. 
     Reference is made to commonly-assigned copending U.S. patent application, Ser. No. 10/063,111, filed Mar. 21, 2002, U.S. Pat. No. 6,615,717 entitled: Symmetrical Parallel Duplex Paper Path Device, by Perdu. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to improvements in transfer of a continuous web substrate between printing, feed, storage, finishing/cutting and/or other devices, especially high speed xerographic printing devices, to include simplex printing systems including or requiring separate, dual, or multiple print engines. 
     In particular, in the embodiments herein the page images for the opposing sides of the web may be transferred efficiently thereto from single conventional photoreceptor or other imaging surface of a single print engine with two separate but closely spaced and alternatingly engaged image transfer stations, and a special web inversion and variable length web loop control system, in plural page image batches, from a common transfer area. 
     Several known patents relate to the field of the present invention, and each of the following are hereby incorporated herein in their entirety: 
     Boeck et al., U.S. Pat. No. 5,467,179 teaches a turnover device for turning a web-shaped recording medium over between two electrophotographic printer or copier devices working in tandem mode, the crossing point of the turning elements is arranged offset a distance of π/2 in the direction of the deflector element relative to the middle of the supplied recording medium, taking the cross sectional dimensions of the turning elements into consideration. The lateral offset of the recording medium is thereby avoided. In other words, the web inverting device of Boeck inverts a web and the web exits in the same paper path direction as its entrance path. This fixed path is useful for in-line tandem simplex printers. 
     Knapp, U.S. Pat. No. 3,548,783 teaches a sheet transport apparatus for both cut sheet and web-type flexible material for changing the path of the material by driving it through guide means curved to change the direction of movement of the flexible material moved therethrough by rollers. By strategically preshaping curved units, paths of feed may be manipulated for inverting the material as the path is changed. A hollow guide track or strategically placed guides and drive rollers are taught by Knapp for use to change the path of the input. In other words, the web inversion apparatus of Knapp requires entrance and exit angles to be fixed and, more particularly, to be fixed at 90 degrees. 
     It is desired to create a web inversion apparatus that both inverts a web substrate and allows wide flexibility between entrance and exit angles. Such a flexible web inversion apparatus may then be coupled with a wide assortment of printing, copying, finishing, and web supply and receiving devices in a manner that enables a web supplying device to work in tandem with a first web receiving device and then, subsequently, to work in tandem with a second web receiving device without the need to substantially move any of the devices other than change in orientation of the web inversion apparatus. 
     The disclosed embodiments of the present invention may desirably employ known existing simplex or duplex web printers and peripheral devices/systems. Duplex web printing may performed by inverting a web for printing between serial printers according to a transfer apparatus and/or systems of the present invention which can be moved and or pivoted to any desired location or angle of web entry or exit. The web transfer system described and illustrated herein inverts and transfers the continuous web to and/or from printing and other devices in a variety of variable and flexible scenarios. For example, faster and more reliable handling of the physical image bearing substrate is made possible for xerographic and other copiers, offset and digital printers, and multifunction machines. 
     In one embodiment of the present invention, a system for inverting a continuous web substrate having a defined direction of movement comprises (a) a continuous web print substrate supply system providing controlled feeding of said continuous web print substrate to a single web print substrate receiving system, and (b) a web transfer apparatus for inverting said continuous web, said transfer apparatus including a hinge point whereby an angle of entry of the web substrate to the web transfer apparatus can be varied relative to an angle of exit of the web substrate web from said web transfer apparatus. 
     In another embodiment of the present invention, an apparatus for inverting a web substrate having a width dimension, comprises: (a) a hinge assembly having a hinge axis and a first attachment section and a second attachment section placed along said axis; (b) an entrance turning surface, coupled to the hinge assembly within the first hinge attachment section and having an axis extending away from the hinge assembly, said entrance turning surface having an end section away from the hinge assembly; (c) a second turning surface, coupled to the hinge assembly within the second hinge attachment section at a location spaced apart from the first hinge attachment section, said second turning surface being arranged in a plane substantially parallel to the plane containing the axis of the entrance turning surface and that is substantially parallel to the axis of the hinge assembly, said second turning surface having an axis extending away from the hinge assembly and angled toward the end section of the entrance turning surface; (d) an exit turning surface, coupled to the hinge assembly within the second hinge attachment section at an angle adjustable with respect to the angle at which the entrance turning surface is coupled to the hinge assembly, said exit turning surface having an axis extending away from the hinge assembly in a different plane than the plane containing the axis of the entrance turning surface and having an end section away from the hinge assembly; and (e) a third turning surface, coupled to the hinge assembly within the first hinge attachment section at a location spaced apart from the second hinge attachment section, said third turning surface being arranged in a plane substantially parallel to the plane containing the axis of the exit turning member and that is substantially parallel to the axis of the hinge assembly, said third turning surface having an axis extending away from the hinge assembly and angled toward the end section of the exit turning surface; whereby a web paper path is formed within the inverting apparatus by feeding the web over the entrance turning surface, then around the second turning surface toward and around the third turning surface toward the exit turning surface where it is turned before exiting the inverting apparatus. 
     In another embodiment of the present invention, a web inverting apparatus comprises (a) a hinge assembly and (b) an entrance module and an exit module, each such module coupled to said hinge assembly such that the hinge assembly provides variability in the angle between the entrance module and the exit module so that a web supply system may feed a web substrate into the entrance module and the web exits the exit module in an orientation substantially inverted to its entrance orientation and so that the web substrate may enter the entrance module at one angle in respect to a web substrate supply system and exit at a different angle. 
     In yet another embodiment of the present invention, a method for inverting a web substrate in a web inverting device comprises: (a) feeding the web substrate around an entrance turning surface toward a second turning surface, said entrance turning surface being coupled to a hinge assembly within a first attachment section of said hinge assembly and said entrance turning surface having an end section away from the hinge assembly; (b) weaving the web substrate path around the second turning surface toward a third turning surface, said second turning surface being coupled to the hinge assembly within a second hinge attachment section at a location spaced apart from the first hinge attachment section, said second turning surface being arranged in a plane substantially parallel to the plane containing the axis of the entrance turning surface and that is substantially parallel to the axis of the hinge assembly, said second turning surface having an axis extending away from the hinge assembly and angled toward the end section of the entrance turning surface; (c) turning the web substrate path around the third turning surface toward an exit turning surface, said third turning surface being coupled to the hinge assembly within the first hinge attachment section at a location spaced apart from the second hinge attachment section, said third turning surface being arranged in a plane substantially parallel to the plane containing the axis of the exit turning member and that is substantially parallel to the axis of the hinge assembly, said third turning surface having an axis extending away from the hinge assembly and angled toward the end section of the exit turning surface; and (d) exiting the web substrate from the web inverting device by turning the web substrate around the exit turning surface toward a preferred exit orientation, said exit turning surface being coupled to the hinge assembly within the second hinge attachment section at an angle adjustable with respect to the angle at which the entrance turning surface is coupled to the hinge assembly, said exit turning surface having an axis extending away from the hinge assembly in a different plane than the plane containing the axis of the entrance turning surface and having an end section away from the hinge assembly. 
     In the description herein the term “web” refers to an elongated flexible material of paper, plastic, or other suitable physical substrate for printing images thereon. As to specific components of the subject apparatus, or alternatives therefor, it will be appreciated that, as is normally the case, some similar components are known per se in other apparatus or applications which may be additionally or alternatively used herein, including those from art cited herein. All references cited in this specification, and their references, are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features, and/or technical background. What is well known to those skilled in the art need not be described here. 
    
    
     Various of the above-noted and further features and advantages will be apparent from the specific apparatus and its operation described in the examples below, including the drawing figures (approximately to scale) wherein: 
     FIG. 1 is a schematic side view of one example of a continuous web simplex printing system with a single xerographic print engine; 
     FIG. 2 is a web inverting transfer module of the present invention; 
     FIG. 3 is a web inverting transfer module and system of the present invention; 
     FIG. 4 is a top view of web inverting transfer module of the present invention; 
     FIG. 5 is a top view of web inverting transfer module of the present invention; 
     FIG. 6 is a web inverting transfer module and system of the present invention; 
     FIG. 7 is a web inverting transfer module and system of the present invention; 
     FIG. 8 is a web inverting transfer module and system of the present invention; and 
     FIG. 9 is a web inverting transfer module and system of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is one example or embodiment of a simplex web printing system  10  for printing page images onto one side of a continuous web substrate  12 . The web  12  may be duplex printed on both of its sides, such as by printing on a first side of web  12  utilizing a first web printing system  10 , then inverting web  12  and printing on the second (non-imaged) side of  12  utilizing a second web printing system similar to or different from printing system  10  (not shown in FIG.  1 ). A tensioning roller  53  may be employed to maintain the proper tension on web  12 . A pretransfer nip  52  may position the web prior to transfer station  22 . The paper supply roll input feed system may be designed to accommodate web steering systems (not shown) to achieve lateral edge registration requirements. The roll  13  from which the continuos web  12  is being fed to be printed in the printing system  10 , and various other conventional or known components, may be likewise employed to feed web  12  and need not be fully illustrated or discussed here. Alternatively, web  12  can be fed to printing system  10  via alternate web feeding path  54  (shown in phantom in FIG.  1 ), rather than being fed from roll  13 . 
     The printing system  10  shows a single exemplary conventional xerographic laser printing engine which is normally only capable of simplex web printing. Various such printers can be used in the subject printing system  10 . In this exemplary print engine a conventional single endless belt photoreceptor  16  is being conventionally sequentially latent imaged with page images, such as by a ROS laser printing imaging system  18 , or an LED bar, or the like. The latent images are developed with visible image developer material by a development system  20 , which may include plural development units for plural colors (not shown in FIG.  1 ). At an image transfer station area or position  22 , the developed images are normally transferred from the photoreceptor  16  to one side of web  12 . Within the printing system  10  a conventional xerographic fusing system  23  is provided in which the transferred developed images are fused to web  12 . 
     Printing system  10  may be conventionally controlled by a conventional programmable controller  100 , as described above. As per the above-cited art, the controller  100  here may desirably be automatically partially reprogrammed by or in accordance with a particular transfer module adjacent to printing system  10  (not shown in FIG.  1 ). In particular here, reprogramming the page image spacing and/or sequence on the photoreceptor between that appropriate for image transfers to a continuous web. Further, imaging of cut sheet original documents can be performed under the control of controller  100  using digital recirculating document scanner  50 . 
     In this system  10 , the images to be printed may be sequentially transferred to appropriate page order opposing side areas of the continuous web  12 . As is known in xerography, in the image transfer area, the web may be driven at the same speed as the photoreceptor by the electrostatic tacking of the paper to the photoreceptor. A conventional corotron or scorotron such as  72  may be mounted behind the web  12  for conventional corona charge toner transfer. 
     Turning now the further details of the web printing system  10  of FIG. 1, it may be seen that a web paper path system is provided for imaged on a the first side of web  12  at transfer station  72 , and fused to web  12  at roll fuser  23 . Thereafter, web  12  exits printing system  10  at exit point  56 . 
     As shown, the web may be pushed into and held in the first transfer station  72  against the photoreceptor for first side image transfer by a commonly movable pair of rollers on each side of the transfer corona source for that transfer. 
     FIG. 2 shows a web inverting transfer apparatus  200  of the present invention that inverts the simplex printed web  12  (such as from printing system  10 ) in a manner such as will permit web  12  to be imaged on the non-imaged side of web  12  such as by a second printing system  10 . Rather than feeding web  12  from roll  13  as shown in FIG. 1, web  12  can be fed to the second printing system  10  via alternate web feeding path  54  via web inverting transfer apparatus  200 . Web  12  is fed over roll  202 , which forms an entrance turning surface coupled, in this embodiment, to hinge assembly  214  in its top section in an orientation approximately perpendicular to the axis of hinge assembly  214 . The web is turned by roll  202  toward and around roll  204  which forms a second turning surface. Roll  204  is coupled to hinge assembly  214  at a position spaced apart from the attachment point of roller  202 . Both rolls  202  and  204  are shown mounted on frame  212  which, in turn, is rotatably coupled to hinge assembly  214 . The axes of the entrance roll  202  and second turning roll  204  extend away from the hinge assembly and converge proximate to the end section of entrance turning roll  202 . Together, entrance turning surface  202  and second turning surface  204  comprise a first module fixedly held in relation to each other within frame  212 . 
     After being turned around turning surface roll  204 , web  12  continues around rotatably mounted roller  206  which forms a turning surface with an axis substantially parallel to the axis of the hinge assembly. Thereafter, web  12  continues around roll  208 , which forms a third turning surface, and then around roll  210 , forming the exit turning surface. As shown, exit roll  208  is coupled to hinge assembly  214  in its top section while third turning surface roll  210  is coupled to hinge assembly  214  at a location spaced apart from roll  208  and, in this embodiment, in an approximately perpendicular orientation to the axis of hinge assembly  214 . Both rolls  210  and  208  are shown mounted on frame  216  which, in turn, is rotably coupled to hinge assembly  214 . The axes of the exit roll  208  and third turning roll  210  extend away from the hinge assembly and converge proximate to the end section of exit turning roll  208 . Together, exit turning surface  208  and third turning surface  210  comprise a second module fixedly held in relation to each other within frame  216 . 
     Roller  206  is rotatably mounted at hinge assembly  214 . Hinge assembly, or hinge point,  214  permits the angle between frame  212  and frame  216  to be varied between 0 and 180 degrees in the embodiment shown in FIG.  2 . In this manner, multiple printing systems can be positioned at any angle relative to the web output (such as via exit point  56  as shown in FIG. 1) of a first printing system  10  and the web input of a second printing system  10  (such as via web feed path  54  as shown in FIG.  1 ). Second printing system may be configured in a manner (not shown) as may permit exit of the duplex printed web at an exit point above or below web inverting transfer apparatus  200 , for subsequent reeling, cutting into individual sheets or other storage or finishing operations as are well known in the art of printing and document finishing. 
     FIG. 3 shows a web inverting transfer apparatus  300  of the present invention that inverts the simplex printed web  12  (such as from printing system  10 ) in a manner such as will permit web  12  to be imaged on the non-imaged side of web  12  such as by a second printing system  110 . Rather than feeding web  12  from roll  13  as shown in FIG. 1, web  12  can be fed to the second printing system  10  via alternate web feeding path  54  via web inverting transfer apparatus  300 . Web  12  is fed over turn point  302  and then around turn point  304 , both shown fixed on perforated turn member  314  mounted on frame  320 . Web  12  continues around perforated turn member  316 . Thereafter, web  12  continues around turn point  308  and then around turn point  310 . Perforated turn members  316 ,  314 ,  318  are each supplied with a pressurized air flow from air supply system  306  via air supply lines  301 , whereby web  12  moves across each turn point  302 ,  304 ,  308  and  310  and perforated turn member  316 , while riding on an air cushion provided by air exit perforations in each perforated turn member  314 ,  318  and  316 . Perforated member  316  is mounted at hinge point  324 . Hinge point  324  permits the angle between frame  320  and frame  322  to be varied between 0 and 180 degrees in the embodiment shown in FIG.  3 . Hinge frame mechanism  312  permits the angle between frame  320  and frame  322  to be fixed in a manner so as to prevent drift or other variance to occur. 
     In the manner shown in FIG.  3  and as discussed in relation to FIGS. 4 and 5, multiple printing systems or any appropriate web supplying device or web receiving device can be positioned at any angle relative to the web output (such as via exit point  56  as shown in FIG. 1) of a first printing system  10  and the web input of a second printing system  110  (such as via web feed path  54  as shown in FIG.  1 ). 
     FIG. 4 shows a top view of web inverting transfer apparatus  200 . Roll  202  is shown in this view on frame  212 ; roll  208  is shown on frame  216 . Hinge point  214  permits the angle between frame  212  and frame  216  to be varied to 0 degrees as shown in FIG.  4 . 
     FIG. 5 shows a top view of web inverting transfer apparatus  200 . In this case, hinge frame mechanism  312  permits the angle between frame  212  and frame  216  to be fixed in a manner so as to prevent drift or other variance to occur. FIG. 4 shows hinge frame  312  collapsed whereas FIG. 5 shows hinge frame mechanism  312  opening the angle between frames  212  and  216  to approximately 120 degrees. 
     It can be further understood that a web inverting transfer apparatus of the present invention may include a perforated turn member  316  supplied with a pressurized air flow from air supply system  306  (as shown and described in conjunction with FIG. 3) in combination with a frame  212  with roll  202  and  204 , and frame  216 , with rolls  208  and  210  (as shown and described in conjunction with FIG.  2 ). Further, when air supply line  301  supplies air from air supply system  306  to a rotation point such as shown in FIG. 3, perforated turn member  316  may also rotate as web  12  passes over said perforated turn member  316 . Likewise, rolls  202 ,  204 ,  206 ,  208  and  210  (as shown in FIG. 2) when supplied with a pressurized air flow from air supply system  306  in a manner as perforated turn member  316  is supplied with a pressurized air flow from air supply system  306  (as shown in FIG.  3 ), may likewise enable web  12  to be separated by an air cushion from each rotating roll  202 ,  204 ,  206 ,  208  and  210 . 
     FIG. 6 shows a top view of web inverting transfer apparatus  200 . Hinge point  214  permits the angle between frame  212  and frame  216  to be varied to 0 degrees as shown in FIG.  4 . Web  12  is shown being printed on both sides, by printing on a first side of web  12  with printing system  10 , inverting web  12  with web inverting transfer apparatus  200 , and then printing on a second side of web  12  with printing system  110 . 
     FIG. 7 shows a top view of web inverting transfer apparatus  200 . Hinge point  214  permits the angle between frame  212  and frame  216  to be varied to 90 degrees as shown. Web  12  is shown being printed on both sides, by printing on a first side of web  12  with printing system  10 , inverting web  12  with web inverting transfer apparatus  200 , and then printing on a second side of web  12  with printing system  110 . It is understood that instead of printing system  10 , web  12  could be supplied to inverting transfer apparatus  200  by any web substrate supplying device, including, without limitation, roll feeders, interim finisher devices, etc. Similarly, printing system  110  can be replaced by any number of web substrate receiving systems, including, without limitation, roll receivers, finisher devices, post-processing devices, etc. 
     FIG. 8 shows a top view of web inverting transfer apparatus  200 . Web  12  is shown being printed on both sides, by printing on a first side of web  12  with printing system  120 , inverting web  12  with web inverting transfer apparatus  200 , and then printing on a second side of web  12  with printing system  110 . Printing systems  10  and  130  are shown idle; with rotation of and/or varying the angle of entry and exit of web  12 , web inverting transfer apparatus  200  can be used to feed between any of printing systems  10 ,  110 ,  120  and  130  so as to print on both sides of web  12 . 
     FIG. 9 likewise shows a top view of web inverting transfer apparatus  200 . Web  12  is shown being printed on both sides, by printing on a first side of web  12  with printing system  10 , inverting web  12  with web inverting transfer apparatus  200 , and then printing on a second side of web  12  with a second printing system  10 . 
     A finisher  5  (such as for cutting the web into individual sheets and otherwise stacking, stapling or processing said individual sheets) is shown as idle in FIG. 9. A web storage reel (such as for feeding web  12  as shown by roll  13  in FIG. 1) is likewise shown as idle in FIG.  9 . By varying the position and angle of web inverting transfer apparatus  200 , finisher  5  or web storage reel  7  may engage web  12  during activation. In this manner, multiple printing systems, web feeders, finishers and other devices can be positioned at any angle relative to the web output for inversion and transport via a web inverting transfer apparatus of the present invention. 
     Variously disclosed in the above embodiments is an architecture and method for accomplishing two sided printing on a single imaging or print engine (xerographic or other) onto a continuous web. While the embodiments disclosed herein are preferred, it will be appreciated from this teaching that various alternatives, modifications, variations or improvements therein may be made by those skilled in the art, which are intended to be encompassed by the following claims.