GROUNDING DEVICE WITH ELECTRICALLY CONDUCTIVE CUSHION

Abstract

An exemplary grounding device includes an electrically conductive planar member having a hollow, central opening. Arms extend from inner edges of the hollow, central opening of the planar member. Each arm is angled relative to a surface of the planar member and each arm includes a facing portion having an electrically conductive cushion attached thereto. Each arm is approximately the same size and is configured to contact a shaft extending through the hollow, central opening of the planar member to form an electrical connection between the planar member and the shaft. The electrically conductive cushion is between the arm and the shaft. A tab projection extends from an outer edge of the planar member. Each tab projection is in the same plane as the planar member.

Claims

1. A device, comprising: a conductive photosensitive drum; a circular flange including a first portion having a first diameter for protruding above a surface of said conductive photosensitive drum and a second portion having a second diameter for inserting into an inside diameter of said conductive photosensitive drum, said second diameter being relatively smaller than said first diameter, said circular flange having an aperture centrally located therein; a grounding device comprising an electrically conductive plate mounted in said circular flange, said grounding device comprising a planar member having a hollow, central opening; and a drive shaft extending into said conductive photosensitive drum through said aperture of said circular flange and through said hollow, central opening of said grounding device, said grounding device further comprising a pair of arms connected to and extending from inner edges of said hollow, central opening of said planar member, each arm of said pair of arms being angled relative to a surface of said planar member, each arm of said pair of arms including a distal end portion having an electrically conductive cushion thereon, said electrically conductive cushion contacting said drive shaft, said electrically conductive cushion being between each said arm and said drive shaft and forming an electrical connection between said grounding device and said drive shaft, and said grounding device further comprising a pair of tab projections connected to and extending from outer edges of said planar member, each tab projection of said pair of tab projections being in the same plane as said planar member, each tab projection of said pair of tab projections being folded over said second portion of said circular flange and forming an electrical connection between said grounding device and said conductive photosensitive drum.

2. The device according to claim 1, wherein said electrically conductive cushion comprises a foam pad embedded with electrically conductive fibers or a non-conductive foam pad wrapped in an electrically conductive cover.

3. The device according to claim 1, wherein said electrically conductive cushion comprises conductive plastic or conductive rubber.

4. The device according to claim 1, wherein said arms comprise spring clips pressing against an outer surface of said drive shaft, said electrically conductive cushion being between each spring clip and said drive shaft.

5. The device according to claim 1, further comprising: a bridge connected to said distal end portion of each said arm, said electrically conductive cushion being disposed between said arms and contacting against the bridge, an end of said drive shaft being pressed against said electrically conductive cushion.

6. The device according to claim 1, wherein said electrically conductive cushion is attached to said grounding device using an electrically conductive adhesive.

7. The device according to claim 1, said grounding device further comprising: mounting devices configured to attach said grounding device to said circular flange.

8. An image forming device, comprising: a printer engine; and a photosensitive drum assembly mounted in said printer engine, said photosensitive drum assembly comprising: a cylindrical drum having a photosensitive layer on an outer surface thereof; a first end cap and a second end cap, each of said end caps being configured to fit into opposite ends of said cylindrical drum; a drive shaft extending into said cylindrical drum through said first end cap; and a grounding device comprising an electrically conductive plate fixed to an inner face of said first end cap, said grounding device comprising: a planar member having a central opening, a pair of arms connected to and extending from inner edges of said central opening of said planar member, each arm of said pair of arms being angled relative to a surface of said planar member, and having an electrically conductive cushion attached thereon, said electrically conductive cushion contacting said drive shaft, said electrically conductive cushion being between each said arm and said drive shaft and forming an electrical connection between said grounding device and said drive shaft, and a pair of tab projections connected to and extending from outer edges of said planar member, each tab projection of said pair of tab projections being folded over a lip of said first end cap and forming an electrical connection between said grounding device and said cylindrical drum.

9. The image forming device according to claim 8, wherein said electrically conductive cushion comprises a foam pad embedded with electrically conductive fibers or a non-conductive foam pad wrapped in an electrically conductive cover.

10. The image forming device according to claim 8, wherein said electrically conductive cushion comprises conductive plastic or conductive rubber.

11. The image forming device according to claim 8, wherein said arms comprise spring clips pressing against an outer surface of said drive shaft, said electrically conductive cushion being between each spring clip and said drive shaft.

12. The image forming device according to claim 8, further comprising: a bridge connected to a distal end portion of each said arm, said electrically conductive cushion being disposed between said arms and contacting against the bridge, an end of said drive shaft being pressed against said electrically conductive cushion.

13. The image forming device according to claim 8, wherein said electrically conductive cushion is attached to said grounding device using an electrically conductive adhesive.

14. The image forming device according to claim 8, said grounding device further comprising: mounting devices configured to attach said grounding device to said first end cap.

15. A grounding device, comprising: an electrically conductive planar member, said electrically conductive planar member having a hollow, central opening; and arms connected to and extending from inner edges of said hollow, central opening of said electrically conductive planar member, each of said arms being angled relative to a surface of said electrically conductive planar member, each of said arms being approximately the same size, and each of said arms having an electrically conductive cushion attached thereon said electrically conductive cushion being positioned to contact a shaft extending through said hollow, central opening of said electrically conductive planar member, said electrically conductive cushion being between said arms and said shaft and forming an electrical connection between said electrically conductive planar member and said shaft.

16. The grounding device according to claim 15, wherein said electrically conductive cushion comprises a foam pad embedded with electrically conductive fibers or a non-conductive foam pad wrapped in an electrically conductive cover.

17. The grounding device according to claim 15, wherein said electrically conductive cushion comprises conductive plastic or conductive rubber.

18. The grounding device according to claim 15, wherein said arms comprise clips pressing against an outer surface of said shaft, said electrically conductive cushion being between each clip and said shaft.

19. The grounding device according to claim 15, further comprising: a bridge connected to distal ends of each of said arms, said electrically conductive cushion being disposed between said arms and contacting against the bridge, said electrically conductive cushion being positioned to contact an end of said shaft being pressed against said electrically conductive cushion.

20. The grounding device according to claim 15, further comprising: a tab projection connected to and extending from an outer edge of said electrically conductive planar member, said tab projection being in the same plane as said electrically conductive planar member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Various examples of the devices and methods are described in detail below, with reference to the attached drawing figures, which are not necessarily drawn to scale and in which:

[0013] FIG. 1 is a schematic diagram of an electrostatic imaging system according to devices herein;

[0014] FIG. 2 is a perspective view of a typical photoreceptor drum;

[0015] FIG. 3 is a perspective view of an exemplary grounding device according to devices herein;

[0016] FIG. 4 is a perspective view of a hub flange with an exemplary grounding device according to devices herein; and

[0017] FIG. 5 is a perspective view of a hub flange with another exemplary grounding device according to devices herein.

DETAILED DESCRIPTION

[0018] The disclosure will now be described by reference to a multi-function device that includes an automatic document handler. While the disclosure will be described hereinafter in connection with specific devices and methods thereof, it will be understood that limiting the disclosure to such specific devices and methods is not intended. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure as defined by the appended claims.

[0019] For a general understanding of the features of the disclosure, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to identify identical elements.

[0020] Referring to FIG. 1, a simple electrostatic imaging system is shown, which can be used with devices and methods herein and can comprise, for example, a printer, copier, fax machine, multi-function device (MFD), etc. An electronic or optical image or an image of an original document or set of documents to be reproduced may be projected or scanned onto a charged surface of a photoreceptor drum 100 to form an electrostatic latent image. The latent image is developed with developing material from a toner source 103 to form a toner image corresponding to the latent image. More specifically, a sheet of print media is fed from a selected media sheet tray having a supply of paper to a sheet transport for travel to a transfer station including the photoreceptor drum 100. There, the toned image is electrostatically transferred to the print media. In other words, a surface, such as a printing medium 106, is moved adjacent to (and/or in contact with) the photoreceptor drum 100 and toner is transferred to the printing medium 106 with the assistance of a charged transfer device 109. That is, by operation of the charge induced into the printing medium 106 by the charged transfer device 109, oppositely charged toner is attracted from the photoreceptor drum 100 to the printing medium 106 as the printing medium 106 passes through the nip 112 created between the photoreceptor drum 100 and the charged transfer device 109. The toner remains on the printing medium 106 after it passes through the nip 112, and is fused to the printing medium 106. A controller 115 is connected to the charged transfer device 109 to control operation of the electrostatic imaging system while varying the transfer field of the charged transfer device 109.

[0021] As would be understood by those ordinarily skilled in the art, the electrostatic imaging system shown in FIG. 1 is only one example and the devices and methods herein are equally applicable to other types of printing devices that may include fewer components or more components. For example, while a single photoreceptor drum 100 and paper path are illustrated in FIG. 1, those ordinarily skilled in the art would understand that many more paper paths and additional photoreceptor drums 100 could be included within any printing device used with devices and methods herein.

[0022] In other words, an exemplary imaging system comprises a multifunctional device with print, copy, scan, and fax services. Such multifunctional devices are well known in the art and may comprise print engines based upon liquid or solid ink jet, electrophotography, other electrostatographic technologies, and other imaging technologies. The general principles of electrophotographic imaging are well known to many skilled in the art and are described above as an example of an imaging system to which the present concepts is applicable.

[0023] It should be understood that the controller 115 as used herein may comprise a computerized device adapted to perform (i.e., programmed to perform, configured to perform, etc.) the below described system operations. According to devices and methods herein, the controller 115 comprises a programmable, self-contained, dedicated mini-computer having a central processor unit (CPU). Computerized devices that include chip-based central processing units (CPU's) 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. The details of such computerized devices are not discussed herein for purposes of brevity and reader focus.

[0024] FIG. 2 shows a photoreceptor drum 100, on the surface of which an electrostatic latent image is formed. The photoreceptor drum 100 has a photosensitive drum tube 205 and flanges 208, 211. The photosensitive drum tube 205 is obtained by forming a conductive metal into a cylindrical shape. The photosensitive drum tube 205 can have a photosensitive layer, for example an organic photoconductor (OPC), formed on the peripheral surface of the metal tube. Openings, such as 214, are formed on the ends of the photosensitive drum tube 205, and fittings, such as 217, having a specific length and a smaller wall thickness are provided on the ends of the openings 214. In the center of the flange 208, an aperture or support hole 220 is provided. The support hole 220 is fitted with a drive shaft 223 in order to support and rotate the photosensitive drum tube 205. The peripheral surface of the flange 208 defines a contact portion 226 that is inserted in the fitting 217 of the photosensitive drum tube 205.

[0025] FIG. 3 shows an exemplary grounding device, indicated generally as 303, according to the present disclosure. The grounding device 303 comprises a planar member 306 that is made of an electrically conductive material. For example, in some cases, the planar member 306 can be made of copper, aluminum, titanium, stainless steel, phosphor bronze, or other appropriate metal. The planar member 306 includes a central opening 309 that is hollow. As shown in FIG. 3, the central opening 309 may be rectangularly shaped. Other appropriate shapes can be used. Arms 312, 313 extend from inner edges of the central opening 309. Each arm 312, 313 is angled relative to a surface of the planar member 306 and includes a facing portion 316, 317 having an electrically conductive cushion 320 attached thereon. The electrically conductive cushion 320 can be a pad made of foam embedded with electrically conductive fibers or non-conductive foam wrapped in an electrically conductive cover. Alternatively, the electrically conductive cushion 320 can be conductive plastic, conductive rubber, and the like on the arms 312, 313. Further, the electrically conductive cushion 320 can be applied to the arms 312, 313 by direct coating application, molding, or other mechanical attachment to the grounding device 303. Each of the arms 312, 313 is approximately the same size and configured so that the electrically conductive cushion 320 contacts the drive shaft 223 extending through the central opening 309 of the planar member 306. The electrically conductive cushion 320 eliminates metal-to-metal friction at the contact interface. As shown in FIG. 3, the arms 312, 313 may comprise spring clips that press against the side of the drive shaft 223 and form an electrical connection between the grounding device 303 and the drive shaft 223, with the electrically conductive cushion 320 being between the arms 312, 313 and the drive shaft 223.

[0026] As described above, the electrically conductive cushion 320 can be a pad made of foam embedded with electrically conductive fibers or non-conductive foam wrapped in an electrically conductive cover. For example, the electrically conductive cushion 320 may be made of polyurethane foam coated with copper, nickel, or other appropriate material. The electrically conductive cushion 320 may be attached to the arms 312, 313 using an electrically conductive adhesive. In some cases, the electrically conductive cushion 320 can be directly coated or molded onto the arms 312, 313. The electrically conductive cushion 320 eliminates metal-to-metal contact at the interface between the grounding device 303 and the drive shaft 223 of the sort that causes fretting and thus the possibility of corrosion. Moreover, the electrically conductive cushion 320 can maintain electrical contact with the drive shaft 223 in the event of misalignment of the drive shaft 323 with the flange 208. The flange 208 and the drive shaft 223 are intended to move together so there should be no relative motion between the drive shaft 223 and the grounding device 303. However, the cushioning effect of the electrically conductive cushion 320 can absorb wobble caused by misalignment between the drive shaft 323 and the flange 208.

[0027] Tab projections 323, 324 extend from an outer edge of the planar member 306. Each tab projection 323, 324 is in the same plane as the planar member 306. The grounding device 303 may include mounting devices, such as 327, to attach the grounding device 303 to the flange 208. As shown in FIG. 4, each tab projection 323, 324 is then folded over the contact portion 226 of the flange 208 so that the tab projections 323, 324 form an electrical connection between the grounding device 303 and the photoreceptor drum 100. As shown in FIGS. 3 and 4, the arms 312, 313 push the electrically conductive cushion 320 in contact with the drive shaft 223 and provide a path for grounding of the photoreceptor drum 100.

[0028] FIG. 5 shows another exemplary grounding device, indicated generally as 505, according to the present disclosure. The grounding device 505 comprises a planar member 306 that is made of an electrically conductive material. For example, in some cases, the planar member 306 can be made of copper, aluminum, titanium, stainless steel, phosphor bronze, or other appropriate metal. The planar member 306 includes a space 508 between opposing ends of the planar member 306. The space is at least as wide as the support hole 220 in the flange 208 (FIG. 2). Arms 312, 313 extend from inner edges of the space 508. Each arm 312, 313 is angled relative to a surface of the planar member 306 and is approximately the same size. The arms 312, 313 are spaced such that they do not contact the shaft 223 extending through the space 508 in the planar member 306. A bridge 511 connects the distal ends of the arms 312, 313. The bridge 511 may be a flat surface in a plane approximately parallel to the plane of the planar member 306. An electrically conductive cushion 320 is disposed between the arms 312, 313 and may be contacting against the bridge 511. The electrically conductive cushion 320 can be a pad made of foam embedded with electrically conductive fibers or non-conductive foam wrapped in an electrically conductive cover. Alternatively, the electrically conductive cushion 320 can be conductive plastic, conductive rubber, and the like. The electrically conductive cushion may be attached to the arms 312, 313. Alternatively, the electrically conductive cushion may be attached to the bridge. As shown in FIG. 5, the electrically conductive cushion 320 may be configured so that the electrically conductive cushion 320 contacts the end of the drive shaft 223 extending through the space 508 between opposing ends of the planar member 306. The electrically conductive cushion 320 eliminates metal-to-metal friction at the contact interface. The end of the drive shaft 223 may press against the electrically conductive cushion 320 and form an electrical connection between the grounding device 505 and the drive shaft 223, with the electrically conductive cushion 320 being between the arms 312, 313 adjacent to the end of the drive shaft 223.

[0029] The electrically conductive cushion 320 can be a pad made of foam embedded with electrically conductive fibers or non-conductive foam wrapped in an electrically conductive cover. For example, the electrically conductive cushion 320 may be made of polyurethane foam coated with copper, nickel, or other appropriate material. The electrically conductive cushion 320 may be attached to the arms 312, 313 or the bridge 511 using an electrically conductive adhesive. In some cases, the electrically conductive cushion 320 can be molded between the arms 312, 313 or mechanically attached between the arms 312, 313. The electrically conductive cushion 320 eliminates metal-to-metal contact at the interface between the grounding device 505 and the drive shaft 223 of the sort that causes fretting and thus the possibility of corrosion. Moreover, the electrically conductive cushion 320 can maintain electrical contact with the drive shaft 223 in the event of misalignment of the drive shaft 323 with the flange 208. The flange 208 and the drive shaft 223 are intended to move together so there should be no relative motion between the drive shaft 223 and the grounding device 505. However, the cushioning effect of the electrically conductive cushion 320 can absorb wobble caused by misalignment between the drive shaft 323 and the flange 208.

[0030] Tab projections 323, 324 extend from an outer edge of the planar member 306. Each tab projection 323, 324 is in the same plane as the planar member 306. Each tab projection 323, 324 is folded over the contact portion 226 of the flange 208 so that the tab projections 323, 324 form an electrical connection between the grounding device 303 and the photoreceptor drum 100.

[0031] 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, it is not intended 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.

[0032] 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.

[0033] 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 not described in detail herein to keep this disclosure focused on the salient features presented. The devices and methods herein can encompass devices that print in color, monochrome, or handle color or monochrome image data. All foregoing devices and methods are specifically applicable to electrostatographic and/or xerographic machines and/or processes.

[0034] The terminology used herein is for the purpose of describing particular devices and methods only and is not intended to be limiting of this disclosure. As used herein, the singular forms a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises, comprising, includes, and/or including, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0035] 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.

[0036] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The descriptions of the various devices and methods of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the devices and methods disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described devices and methods. The terminology used herein was chosen to best explain the principles of the devices and methods, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the devices and methods disclosed herein.

[0037] 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 devices 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.