Patent Application
20120200030
Embodiments herein generally relate to sheet transportation devices and more particularly to a beltless vacuum transport apparatus that includes grooves in the rollers.
Various devices, such a printers and finishing machines, need to transport sheets. For example, many printing devices transport sheets to and from a marking device to allow the marking device to print markings on the sheet. There are many forms of such sheet transportation devices, including ones that use rolls (which are sometimes referred to herein as rollers), belts, vacuum devices, etc.
An exemplary sheet transportation apparatus herein can be used in any device that moves sheets of media, such as a printing device that has a media path that moves sheets of media by a marking device. The media path includes at least one beltless vacuum transport (BVT) that has a plurality of adjacent rollers. Rotation of the rollers moves the sheets of media in a process direction.
Each of the rollers comprises a rounded external surface and an axis about which the external surface rotates. Each axis can be parallel to each other axis (if, for example, the BVT is in a straight line) and the axes of the rollers are generally perpendicular to the process direction of the media path. The external surfaces of the rollers are spaced from each other by gaps referred to as “inter-roller spaces.”
A fan is positioned on a first side of the rollers. The fan draws air through the inter-roller spaces to create a vacuum force on a second side of the rollers. The vacuum force maintains the sheets of media in contact with the second side of the rollers.
The external surface of each of the rollers comprises a plurality of first regions having a first diameter and a plurality of second regions having a second diameter different than the first diameter. The first regions and the second regions of the external surface are adjacent one another and alternate along the length of the external surface of each of the rollers.
The external surface of each of the rollers further comprises sidewalls connecting the first regions to the second regions. The sidewalls between the first and second regions can be positioned at a right angle to the axis of each roller, so that the sidewalls are parallel to the process direction of the media path. Alternatively, the sidewalls between the first and second regions can be positioned at a non-right angle (obtuse angle or acute angle) to the axis of each roller, so that the sidewalls are not parallel to the process direction of the media path.
The first regions of adjacent rollers are positioned next to one another and the second regions of the adjacent rollers are positioned next to one another. The inter-roller spaces between the first regions of adjacent rollers are greater than inter-roller spaces between the second regions of the adjacent rollers.
These and other features are described in, or are apparent from, the following detailed description.
Various exemplary embodiments of the systems and methods are described in detail below, with reference to the attached drawing figures, in which:
Beltless vacuum transport systems include a series of rollers mounted in a vacuum chamber box (for a fuller description of conventional BVT systems, see U.S. Pat. No. 6,873,821, the complete disclosure of which is incorporated herein by reference). For example, as shown as
In the drawings, the side of the rollers 100 that contacts the sheet of media 102 is arbitrarily referred to as the “top” of the structure, and the opposite side of the rollers 100 is referred to as the “bottom” of the structure to simplify the description; however, those ordinarily skilled in the art would understand that the structure is not limited to this orientation and that it could have any orientation appropriate for a given design.
Some form of vacuum producing device 104 is positioned below the bottom of the rollers 100. While this vacuum device 104 is illustrated as a simple rectangular duct, those ordinarily skilled in the art would understand that the vacuum device 104 could have any shape appropriate for a given device and could be positioned at any location relative to the rollers 100. Generally, the vacuum device 104 includes a fan to draw air from the top of the rollers toward the bottom of the rollers 100 (as indicated by the arrows in
In addition, the BVT system includes one or more drive mechanisms 106 (such as drive motors, etc.) that can rotate the rollers 100. While all the rollers 100 are illustrated as including an individual drive mechanism 106, those ordinarily skilled in the art would understand that less than all the rollers 100 could include the drive mechanisms 106. Further, the drive mechanisms 106 could be linked together through a chain, belt, gears, etc., to allow a single drive motor to simultaneously rotate all the rollers 100. As the rollers 100 rotate, they move the sheet of media 102 in the process direction and the vacuum force from the vacuum device 104 maintains the sheet of media 102 in contact with the rollers 100.
As illustrated in
Another of the dysfunctions of the BVT technology involves the use of silicon material for the rollers 100. Silicon foam material provides great traction at low cost, but this roller material is susceptible to contamination. Loss of document holding force occurs when the diameter (d2) of the rollers 100 increases when silicon material rollers get contaminated with silicon oil, paper dust, and toner particles (see
While one could make the roll diameter smaller in order to maintain a larger gap between the rolls (and avoid choking the air flow as shown in
In view of such issues, the embodiments herein can provide alternating angled or spiral grooves in the rollers to provide a continuous airflow instead of air flow only between rolls. This provides an air passage regardless of roll diameter changes due to contamination. The angled grooves provide holding force in two axes. The alternating angle between rolls also helps distribute any heat transient to the local area.
More specifically, as illustrated in
A fan in the vacuum apparatus 104 is positioned on a “first” side (bottom) of the rollers 200. As mentioned above, the fan draws air through the inter-roller spaces to create a vacuum force on a “second” side (top) of the rollers 200. The vacuum force maintains the sheets of media in contact with the second side of the rollers 200.
As shown in
The first regions 202 of adjacent rollers 200 are positioned next to one another and the second regions 204 of the adjacent rollers 200 are positioned next to one another. Thus causes the inter-roller spaces between the first regions 202 of adjacent rollers 200 to be greater than inter-roller spaces between the second regions 204 of the adjacent rollers 200.
The external surface of each of the rollers 200 further comprises sidewalls connecting the first regions 202 to the second regions 204. The sidewalls between the first 202 and second regions 204 can be positioned at a right angle to the axis of each roller, so that the sidewalls are parallel to the process direction of the media path.
As shown in
Alternatively, as shown in
The grooves created by the difference between the first regions 202/232 and the second regions 204/234 provide a continuous holding force, minimizing the potential effects of external forces acting on document. This increases paper handling robustness. Further, these systems are easy to implement and only require a simple additional machining operation or addition of a feature to the mold (urethane rolls design). The embodiments herein eliminate the sensitivity to silicon oil and other contaminates and the grooves provide a continuous holding force
The exemplary sheet transportation apparatus shown in
The printing device 190 can include any form of scanning device, such as one used within a document handler 194 of a printing device 190. The printer body housing 190 has one or more functional components that operate on power supplied from the alternating current (AC) 188 by the power supply 182. The power supply 182 converts the external power 188 into the type of power needed by the various components.
The printing device 190 includes a controller/processor 184, at least one marking device (printing engine) 170 operatively connected to the processor 184, a media path 172 positioned to supply sheets of media from a paper tray 192 to the marking device(s) 170 and a communications port (input/output) 186 operatively connected to the processor 184 and to a computerized network external to the printing device. After receiving various markings from the printing engine(s), the sheets of media pass to a finisher 198 which can fold, staple, sort, etc., the various printed sheets.
Further, the printing device 190 includes at least one accessory functional component, such as the sheet supply/paper tray 192, finisher 198, graphic user interface assembly 196, etc., that also operate on the power supplied from the external power source 188 (through the power supply 182).
The processor 184 controls the various actions of the printing device. A computer storage medium 180 (which can be optical, magnetic, capacitor based, etc.) is readable by the processor 184 and stores the scanned images and instructions that the processor 184 executes to allow the multi-function printing device to perform its various functions, such as those described 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, processors, etc. are well-known and readily available devices produced by manufacturers such as Dell Computers, Round Rock Tex., USA and Apple Computer Co., Cupertino Calif., USA. Such computerized devices commonly include input/output devices, power supplies, 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 embodiments described herein. Similarly, scanners and other similar peripheral equipment are available from Xerox Corporation, Norwalk, Conn., 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 by those ordinarily skilled in the art and are discussed in, for example, U.S. Pat. No. 6,032,004, the complete disclosure of which is fully incorporated herein by reference. The embodiments herein can encompass embodiments that print in color, monochrome, or handle color or monochrome image data. All foregoing embodiments 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).
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. The claims can encompass embodiments in hardware, software, and/or a combination thereof. Unless specifically defined in a specific claim itself, steps or components of the embodiments herein cannot be implied or imported from any above example as limitations to any particular order, number, position, size, shape, angle, color, or material.
