Continuous flexible belt loading device

A belt loading apparatus has been provided for loading a flimsy continuous belt onto a belt support and drive assembly including a vertical front end having a first shape and without damage to the belt. The belt loading apparatus includes a wall member defining a sleeve including an outer surface having a total outer surface area, a first edge and a second and opposite edge. The second edge has a vertical profile having a second shape such that the second shape of the second edge is a mirror image of the first shape of the belt support and drive assembly. The belt loading apparatus then includes friction reducing members formed on the outer surface of the sleeve for temporarily supporting and spacing a flimsy continuous belt to be loaded onto the belt support and drive assembly. The friction reducing members each have a belt contact area such that a sum total of belt contact areas of all the friction reducing members is significantly less than the total outer surface area of the sleeve.

This invention relates generally to a reprographic printing machine, and more particularly, to a system in a such as a machine for easily mounting and positioning a large continuous flexible belt, such as a photoreceptor belt, onto the belt support and drive assembly or belt module for such a belt. Specifically, this invention relates to a simple, fast and easy apparatus for mounting and positioning a flexible type photoreceptor belt onto the belt support and drive assembly for the photoreceptor belt in a xerographic printing machine, and in a manner that substantially prevents damage to edges of the photoreceptor belt.

In reprographic apparatus, a large belt photoreceptor, such a multiple layered photoreceptor belt, is used; but the belt has a large circumference, a low rigidity, and excessive flexibility. As a consequence, the belt is unwieldy for one person to handle safely without causing some creases and denting damages in any attempts to load it onto a belt module. Any such damages of course will result in image quality defects on printed copies.

The belt support and drive assembly in reprographic machines that use such large belts is typically constructed with multiple components whose edges present obstacles to simply and easily sliding the photoreceptor belt onto the belt support and drive assembly. Ordinarily, the edges of a multiple layered photoreceptor belt tend to curl inwardly, thereby catching on the machine hardware and creating kinks in the imaging area of the photoreceptor belt.

To alleviate this problem, it is known as disclosed for example in commonly owned U.S. Pat. No. 6,304,737 issued Oct. 16, 2001 to Dotschkal (pertinent portions of which are incorporated herein by reference), to pre-position a removable smooth covering boot over the drive and support system or belt module, and then mounting the photoreceptor belt over the boot. After such mounting, the boot is then removed leaving the photoreceptor on the drive and support system.

It has been found that where the photoreceptor belt is very long, for example a 10-pitch or 10 image frames belt, it is nearly impossible to mount it onto the belt support and drive assembly or belt module without causing wrinkles or without touching parts of it against components of the drive and support assembly. The belt module for such a belt itself is usually a huge assembly of many elements that leave very little room for mounting the photoreceptor belt into its place. Where such a belt module has a unique shape, it is additionally necessary for the photoreceptor belt to be pre-shaped to the shape of the module before attempts are made to mount it onto the module.

Additionally, it has been found that during the process of removing the smooth boot after using it as above to mount the photoreceptor to the module, the two then to stick together due to friction and electrostatic forces, thus making it difficult to separate the smooth boot from the photoreceptor and risking damage to the photoconductive characteristics of the photoreceptor belt.

There is therefore a need for a simple, fast and easy apparatus for mounting and positioning a flexible continuous belt such as photoreceptor belt onto the belt support and drive module in a manner that substantially reduces friction and prevents electrostatic damage to the photoreceptor belt.

The present invention provides a belt loading apparatus for loading a flimsy continuous belt onto a belt support and drive assembly including a vertical front end having a first shape and without damage to the belt. The belt loading apparatus includes a wall member defining a sleeve including an outer surface having a total outer surface area, a first edge and a second and opposite edge. The second edge has a vertical profile having a second shape such that the second shape of the second edge is a mirror image of the first shape of the belt support and drive assembly. The belt loading apparatus then includes friction reducing members formed on the outer surface of the sleeve for temporarily supporting and spacing from the outer surface a flimsy continuous belt to be loaded onto the belt support and drive assembly. The friction reducing members each have a belt contact area such that a sum total of belt contact areas of all the friction reducing members is significantly less than the total outer surface area of the sleeve.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention will be described hereinafter in connection with a preferred embodiment thereof, it should be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternative, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

With reference toFIG. 1, there is shown a single pass multi-color xerographic printing machine10, for example, that employs a flimsy continuous photoconductive imaging belt11as is well known. For operation, the belt11is mounted onto and driven by a belt support and drive assembly or belt module200that includes a series of rollers74and76, or bars,13. The belt support and drive assembly200includes a front end202that includes a first perimeter210having a first shape212, for example, an elliptical or oval shape as shown. Usually the photoconductive belt11assumes that same given first shape212when it is mounted onto the belt module or belt support and drive assembly200. In one application as illustrated, the module200and the photoconductive belt11as mounted, each have a major axis120and a minor axis118. The major and minor axes are perpendicular to one another, thus giving each of them the elliptical shape212. The major axis120is substantially parallel to the gravitational vector and arranged in a substantially vertical orientation. The minor axis118is substantially perpendicular to the gravitational vector and arranged in a substantially horizontal direction.

In operation of the single pass multi-color xerographic printing machine10, the photoconductive belt11advances in the direction of arrow12to move successive portions of its external surface sequentially beneath the various xerographic processing stations disposed about the path of movement thereof within the printing machine10. Initially, belt11passes through charging station16that includes a charging device such as a corona generator26that charges the exterior surface of photoconductive belt11to a relatively high, and substantially uniform potential.

After the exterior surface of photoconductive belt11is charged, the charged portion thereof advances to an exposure station that includes a an exposure device such as a raster output scanner (ROS)28, that image-wise illuminates the charged portion of the exterior surface of photoconductive belt11to record a first electrostatic latent image thereon. Alternatively, a light emitting diode (LED) may be used.

This first electrostatic latent image is developed at a development station by developer unit30that deposits charged toner particles of a selected first color on the first electrostatic latent image. After the toner image has been developed as such on the exterior surface of photoconductive belt11, belt11continues to advance in the direction of arrow12to a recharging station18.

Recharging station18includes a recharging device and an exposure device. The charging device for example is a corona generator32that recharges the exterior surface of photoconductive belt11to a relatively high, and substantially uniform potential. The exposure device, for example, a ROS34, image-wise illuminates the charged portion of the exterior surface of photoconductive belt11selectively to record a second electrostatic latent image thereon. This second electrostatic latent image corresponds to the regions to be developed with for example with second color of toner particles. This second electrostatic latent image is now advanced to the next successive developer unit36.

Developer unit36deposits the second color toner, for example magenta toner particles on the electrostatic latent image. In this way, a magenta toner powder image is formed on the exterior surface of photoconductive belt11. After the magenta toner powder image has been developed on the exterior surface of photoconductive belt11, photoconductive belt11continues to advance in the direction of arrow12to image recording station20.

Image recording station20includes a charging device and an exposure device. The charging device includes corona generator38, which recharges the photoconductive surface to a relatively high, substantially uniform potential. The exposure device includes ROS40which illuminates the charged portion of the exterior surface of photoconductive belt11to selectively dissipate the charge thereon to record a third electrostatic latent image corresponding to the regions to be developed with yellow toner particles. This third electrostatic latent image is now advanced to the next successive developer unit42.

Developer unit42deposits yellow toner particles on the exterior surface of photoconductive belt11to form a yellow toner powder image thereon. After the third electrostatic latent image has been developed with yellow toner, belt11advances in the direction of arrow12to the next image recording station22.

Image recording station22includes a charging device and an exposure device. The charging device includes a corona generator44, which charges the exterior surface of photoconductive belt11to a relatively high, substantially uniform potential. The exposure device includes ROS46, which illuminates the charged portion of the exterior surface of photoconductive belt11to record a fourth electrostatic latent image for development with cyan toner particles. After the fourth electrostatic latent image is recorded on the exterior surface of photoconductive belt11, photoconductive belt11advances this electrostatic latent image to the magenta developer unit48.

Cyan developer unit48deposits magenta toner particles on the fourth electrostatic latent image. These toner particles may be partially in superimposed registration with the previously formed yellow powder image. After the cyan toner powder image is formed on the exterior surface of photoconductive belt11, photoconductive belt11advances to the next image recording station24.

Image recording station24includes a charging device and an exposure device. The charging device includes a corona generator50which charges the exterior surface of photoconductive belt11to a relatively high, substantially uniform potential. The exposure device includes ROS52, which illuminates the charged portion of the exterior surface of photoconductive belt11to selectively discharge those portions of the charged exterior surface of photoconductive belt11which are to be developed with black toner particles. The fifth electrostatic latent image, to be developed with black toner particles, is advanced to black developer unit54.

At black developer unit54, black toner particles are deposited on the exterior surface of photoconductive belt11. These black toner particles form a black toner powder image which may be partially or totally in superimposed registration with the previously formed yellow and magenta toner powder images. In this way, a multi-color toner powder image is formed on the exterior surface of photoconductive belt11. Thereafter, photoconductive belt11advances the multi-color toner powder image to a transfer station, indicated generally by the reference numeral56.

At transfer station56, a receiving medium, i.e., paper, is advanced from stack58by sheet feeders and guided to transfer station56. At transfer station56, a corona generating device60sprays ions onto the back side of the paper. This attracts the developed multi-color toner image from the exterior surface of photoconductive belt11to the sheet of paper. Stripping axis roller66contacts the interior surface of photoconductive belt11and provides a sufficiently sharp bend thereat so that the beam strength of the advancing paper strips from photoconductive belt11. A vacuum transport moves the sheet of paper in the direction of arrow62to fusing station64.

Fusing station64includes a heated fuser roller70and a back-up roller68. The back-up roller68is resiliently urged into engagement with the fuser roller70to form a nip through which the sheet of paper passes. In the fusing operation, the toner particles coalesce with one another and bond to the sheet in image configuration, forming a multi-color image thereon. After fusing, the finished sheet is discharged to a finishing station where the sheets are compiled and formed into sets which may be bound to one another. These sets are then advanced to a catch tray for subsequent removal therefrom by the printing machine operator.

One skilled in the art will appreciate that while the multi-color developed image has been disclosed as being transferred to paper, it may be transferred to an intermediate member, such as a belt or drum, and then subsequently transferred and fused to the paper. Furthermore, while toner powder images and toner particles have been disclosed herein, one skilled in the art will appreciate that a liquid developer material employing toner particles in a liquid carrier may also be used.

Invariably, after the multi-color toner powder image has been transferred to the sheet of paper, residual toner particles remain adhering to the exterior surface of photoconductive belt11. The photoconductive belt11moves over isolation roller78which isolates the cleaning operation at cleaning station72. At cleaning station72, the residual toner particles are removed from photoconductive belt11. The belt11then moves under spots blade80to also remove toner particles therefrom.

The large and long photoreceptor belt such as a 10-pitch belt, is very difficult to mount onto a belt module without causing wrinkles or damaging the belt by touching any parts of the module. The belt module for such a belt usually is a huge assembly of lots of xerographic elements that leave very little room for sliding the belt into its place. Attempts to load by sliding necessarily require that the photoreceptor belt take a shape that conforms to the shape of the module during the mounting attempt. This is ordinarily not possible because the photoreceptor belt is a thin flimsy device, about 125 microns in thickness.

Yet proper operation and maintenance of the xerographic printing machine10long term requires that the photoconductive belt11be replaced from time to time. Replacing the belt11involves removing an old and existing belt on the belt module200and then loading a new belt onto the belt module. As pointed out above, the photoconductive or photoreceptor belt11can be a large belt, such as an AMAT belt, and so will be too flexible and unwieldy for one person to handle safely during such loading without causing some damage to the belt. Any such damage of course will result in image quality defects. To prevent such damage, a belt loading apparatus300in accordance with the present invention can be used.

Referring now toFIG. 3, there is illustrated a straight-down hanging wrapped or pre-protected loop122of the flimsy belt11unfolded from its packaged state as disclosed for example in pending and commonly owned U.S. application Ser. No. 10/625,192 filed Jul. 23, 2003. As disclosed therein, unfolding and dropping of the packaged loop122will free a third packaging core (not shown but which initially was external to the wrapped loop122) to fall free, but leave other cores C1and C2inside the flexible belt loop124. With the loop tacking adhesive tape126,128still applied, the protective member380(to be described further below) is thus still intact as a protective loop380over the flexible belt loop124. The two loops124,380together (as the wrapped loop122) can thus be moved and handled for mounting onto the belt loading apparatus300of the present invention, in preparation for loading onto the belt module200in accordance with the present invention.

Referring now toFIGS. 4–9, there is shown in accordance with the present invention, various embodiments of the belt loading apparatus300of the present invention. As shown, the belt loading apparatus300is suitable for mounting and positioning a flimsy continuous belt, such as the photoconductive belt11, onto a belt support and drive assembly or belt module200. The belt module200includes a vertical front end202having a first perimeter210defining a first shape212. The first shape for example is elliptical. The belt loading apparatus300includes a wall member310defining a sleeve320. The sleeve320includes an outer surface330having a total outer surface area A1, a first or front edge334, and a second and opposite or back edge336. The second edge336includes a second perimeter340that has a second shape342. The second shape342of the second edge336is a mirror image of the first shape212of the belt support and drive assembly200.

The belt loading apparatus300also includes friction reducing members350formed or embossed on the outer surface330of the sleeve320, and having a typical height 1 to 10 mils, for temporarily supporting and spacing a flimsy continuous belt such as the belt11just before such belt is loaded onto the belt support and drive assembly200. In order to reduce friction and the risk of electrostatic damage to the belt11, the friction reducing members350each have a belt contact area356that are sized such that a sum total A2of all such belt contact areas356of friction reducing members350is significantly less than the total outer surface area A1of the sleeve320. Each belt contact area of each of the friction reducing members has a convex curved profile as shown.

The friction reducing members350are conductive so as to prevent tribo-electric charging between them and the temporarily supported flimsy continuous belt11. As illustrated inFIGS. 4 and 5, each of the friction reducing members350whether as a ridge352or mound354, comprises or is like a portion of a generally circular projection as shown above the outer surface330of the sleeve320

In a first version, the generally circular projection is a ridge352extending from the at least one or first edge334to a first direction opposite the at least one edge334, and spaced apart a distance S1in an orthogonal direction from adjacent such ridges352.

In another version, the generally circular project is a mound354, for example embossed, and having a circular diameter at the base, and forming part of an array of such mounds354(as shown) spaced apart, one from another, and extending in the first direction from the at least one or first edge334to a point opposite such edge. The array of such mounds354is spaced apart from adjacent such arrays in the generally orthogonal direction relative to the first edge-to-edge direction. A typical circular diameter at the base of the embossed area can be a few millimeters to centimeters and the heights at the center from 25 microns to 500 microns. Since the photoreceptor will come in contact with the sleeve320only at the peak or contact area356of the friction reducing member350, the total contact area A2will be reduced and thereby the friction will be reduced.

In a first embodiment as illustrated inFIGS. 4 and 5, the sleeve320is a semi-solid or semi-rigid belt322having a thickness within a range of 5 mils to 100 mils for providing rigidity. The semi-rigid solid belt is a nickel belt. Alternatively, the semi-rigid belt can be made of a plastic material such as polyethylene, polycarbonates or polyimide films.

Because the sleeve320is to be inserted inside the photoreceptor belt11for supporting it during loading, the sleeve320therefore is required to have very good rigidity. Materials satisfying this requirement include nickel from 5 to 10 mils in thickness, and plastic selected from among polyetheretherketone, polyimide, polyetherimide, polyethersulfone, polysulfone, polymethylpentene, polyvinylidene flouride, ehylene-chloroytifluoroethylene, polycarbonate, biaxially oriented polyvinyl flouride, biaxially oriented polyethylene terephthalate (PET), biaxially oriented polyethylene naphthalate (PEN), and the like. The sleeve belt322should have a outer circumference about 10 mm to about 10 cm smaller than that of the photoreceptor belt11in order to ease inserting it inside the photoreceptor belt loop122. The plastic support, or sleeve belt322as such should have a thickness of between about 5 and about 100 mils in order to provide rigidity. The plastic material for example is a white opaque polyester film available under a trade name of Melinex 359 (trade name of ICI, Inc.)

In a second embodiment as illustrated inFIGS. 6 and 7, the sleeve320is an inflatable pneumatic device324. The inflatable pneumatic device324for example includes internal baffles325and326for producing a desired shape, such as the second shape342, and a desired rigidity thereto. For ease of use, the inflatable pneumatic device324includes a valve member327for example, thus making it deflatable so as to collapse it into a relatively smaller shape and form for carrying about. Thus the invention consists of the pneumatic sleeve324in the shape of an air bag whose cross section has a shape conforming to that of the belt module200.

A technical representative can fill the air bag or sleeve320using the valve device327and exhaust air from a standard vacuum cleaner for example. The belt11is taken out of its shipping container, unwrapped and slipped over the inflated sleeve320.

In both cases, the sleeve320and the belt11on it, can then be juxtaposed and aligned with the front end202of the module200so that the belt11can be slid off of the sleeve320and onto the belt module200. The valve device327can be a simple flapper style check valve to match the vacuum cleaner hose. The second and opposite edge336of the air bag or pneumatic device324is tapered relative to the first edge334(edge that aligns against module), and the internal baffles325,326are provided in order for the device324when inflated to maintain the desired second shape342.

According to one aspect of the present invention, the sleeve320, whether as the belt322or pneumatic device or air bag324, can be pre-loaded first onto a movable and adjustable support stand360, then the flimsy belt11placed over it, for aligning against the front end202of the belt module200. When pre-loading the sleeve320and belt11onto the support stand360, they are loaded front or first edge334first onto extending arms362of the stand360. In this manner, when the assembly is aligned to the front end202of the module200, the belt11is then pushed or slid off second or back edge336first off of the sleeve and onto the belt module200.

As described above, in order for this to work, the sleeve320includes an outer surface330having a total outer surface area A1, a first edge334and a second and opposite edge336. The second edge336has a second perimeter340defining the second shape342. The second shape342of the second edge336is a mirror image of the first shape212of the belt support and drive assembly or belt module200in order to facilitate alignment and loading of the belt11from the sleeve320onto the module200.

Alternatively, as illustrated inFIG. 8, the sleeve320can be pre-loaded first onto a stand360, and then onto a set of removable dowel pins370that are mounted removably around the first perimeter210of the module200. The removable dowel pins370may be mounted as such just inside of the belt path216of the belt module200for aligning the belt11when placed over it. Again, the flimsy belt11(with a protective member380thereover) can then be placed over the sleeve320, in alignment with the front end202of the belt module200. Thereafter, the belt11can finally be slid with little risk of damage from friction from the sleeve320onto the module itself. The dowel pins can then be pulled out of the module. Note that the sleeve320either as a belt322or a pneumatic device324has a second or back edge336perimeter340that defines the second shape342that is approximately a mirror image of the shape of the belt module200.

In the second embodiment where the sleeve320is a pneumatic device324, the belt11can be put over the pneumatic device or air pillow324before the air pillow is inflated. After that the air pillow or pneumatic device324can then be inflated so that the belt11acquires the same shape as that of the pneumatic device, and so that the belt11can slide easily over the pneumatic device onto the belt module200. The assembly of the air bag or pillow324and belt11can then be put on the dowel pins370. The belt is slid off of the sleeve320onto the belt module200. Air pressure in the air bag or pillow324can be adjusted in order to make the sliding of the belt11easier. The air bag or pillow324is then removed from the dowel pins370, deflated and put away for reuse. The dowel pins370can then also be removed and stored away.

As a further alternative to aligning the sleeve320and belt11on it to the machine module200, VELCRO™ strips (not shown) may be provided around the perimeter210of the front end202of the belt module200, and around the perimeter340of the back end or second edge336of the sleeve320for temporary attachment of the two. In the case of the second embodiment, after inflating the pneumatic device or air pillow, it can then be attached to the belt module with the help of such VELCRO™ strips. Thereafter, the procedure is the same as above.

Referring now toFIGS. 3 and 8, the belt loading apparatus300may also include a protective device380having a circumference greater than a circumference of the flimsy continuous belt11, thus allowing the protective device380to slidably fit over the flimsy continuous belt11, even when supported on the sleeve320. The protective device380for example can be black photo paper or it can be a plastic belt having a thickness that is less than the thickness of the sleeve320. When the protective device380is a belt, such belt should be made of a plastic material selected out of the same materials like the support belt or sleeve320, but it should be thinner in thickness, and be within a range of from about 5 to about 20-mil thick. The circumference of the protective belt should be from about 20 mm to 10 cm larger than that of the photoreceptor belt11.

For the same reason, both support sleeve320and protective belt or device380may be conductive in order to avoid tribo-electrical charging. Each may also have a lower surface energy of less than 35 dynes/cm than the photoreceptor belt11in order to ease insertion as well as removal of these belts from the photoreceptor belt11after completion of its loading process onto the machine belt module200.

Alternatively, the belt loading apparatus300may additionally include (a) a holding cavity390located within the sleeve320and adjoining an inner surface331of the sleeve320for temporarily holding the belt support and drive assembly200; (b) at least one opening located at the at least one, back edge336and opening into the holding cavity390for allowing movement of the sleeve320onto and back out over the belt support and drive assembly or module200. The holding cavity390as such has a size and the second shape342for slidably fitting over the belt support and drive assembly200. The sleeve320when defining the holding cavity390has an external diameter that is about 10 mm to 10 cm less than an inner diameter of the flimsy continuous belt11in order to allow the belt11to fit over the sleeve320. The sleeve320thus may include an opposite edge334, and a second opening located at the first edge.

The first edge334and the second edge336have a first diameter and a second diameter respectively, and the first diameter is slightly greater than the second diameter for producing a tapered profile in the sleeve from the first edge334towards the first edge334.

The belt module is usually provided with an adjustable element such as a roller or a backer bar that is relaxed in order to loosen or tighten the tension on the belt. Once the belt is loaded onto the module200as such, the adjustable roller or backer bar can then be tightened. The belt loading apparatus300of the present invention thus will eliminate the problem of photoreceptor belt sticking to a conventional smooth surface device such as the boot of the prior art.

It is, therefore, apparent that there has been provided in accordance with the present invention, a belt loading apparatus for loading a flimsy continuous belt onto a belt support and drive assembly including a vertical front end having a first shape and without damage to the belt. The belt loading apparatus includes a wall member defining a sleeve including an outer surface having a total outer surface area, a first edge and a second and opposite edge. The second edge has a vertical profile having a second shape such that the second shape of the second edge is a mirror image of the first shape of the belt support and drive assembly. The belt loading apparatus then includes friction reducing members formed on the outer surface of the sleeve for temporarily supporting and spacing a flimsy continuous belt to be loaded onto the belt support and drive assembly. The friction reducing members each have a belt contact area such that a sum total of belt contact areas of all the friction reducing members is significantly less than the total outer surface area of the sleeve.