Embodiments herein generally relate to printing devices that feed sheets of media on media paths to printing engines that print on the sheets of media, and more particularly to an improved printing device that includes a nip roll structure that actively adjusts the pivot position of a frame member to maintain proper positional relationships between the two rolls that form the nip.
When moving sheets of media along the media path within a printing device, many different devices such as belts, rolls (which are sometimes referred to herein as rollers) etc., can be utilized. One such media movement mechanism is referred to as a “nip” that is formed at a location where opposing rollers contact one another. Within most nip structures, one of the rollers is driven by a motor or other actuator (directly or indirectly), and the other roller has a specifically designed amount of rolling freedom (rolling resistance) and spring loading against the drive roller that helps achieve various design goals for each specific nip. The rollers that make up the nip can be biased against one another using a spring, piston, or other similar biasing member connected to one or both rollers.
One exemplary printing apparatus herein comprises a marking device, a media path positioned to supply sheets of media to the marking device, and a media supply tray positioned to supply the sheets of media to the media path. Further, a pair of rollers forms a nip adjacent the media supply tray. The rollers rotate in opposite directions to cause the sheets of media to move from the media supply tray to the media path. Additionally, a first frame structure supports a first roller of the pair of rollers. The first frame structure can be in a fixed position and holds the first roller in a fixed location. A second frame structure supports a second roller of the pair of rollers.
The second frame structure is adjustable in a first direction toward the first roller and has a variable pivot position allowing the second frame structure to move in a second direction perpendicular to the first direction. The second frame structure also includes a pivot connection that allows the frame to move in the first direction. A biasing member such as a spring or actuator is connected to the second frame for biasing the second frame in the first direction.
In one embodiment, a series of openings into which the pivot connection connects allow the pivot connection to move in the second direction. In another embodiment, the second frame structure has a slot into which the pivot connection connects that allows the pivot connection to move in the second direction. In an additional embodiment, the second frame structure includes a screw mechanism to which the pivot connection connects, where adjustment of the screw mechanism allows the pivot connection to move in the second direction.
The first roller has a first axis about which the first roller rotates and the second roller has a second axis about which the second roller rotates. A reference line would connect the first axis and the second axis when the first roller and the second roller are not worn and are full size. The second direction would also be perpendicular to the reference line. Further, coordinated movement of the second frame in the first direction and the second direction keeps the second axis on this reference line as the size of the first roller and the second roller decrease because of wear.
Another exemplary printing apparatus herein comprises a marking device, a media path positioned to supply sheets of media to the marking device, and a media supply tray positioned to supply the sheets of media to the media path. Further, the media path includes a pair of rollers that form a nip. The rollers rotate in opposite directions to cause the sheets of media to move along the media path. Additionally, a first frame structure supports a first roller of the pair of rollers. The first frame structure can be in a fixed position and holds the first roller in a fixed location. A second frame structure supports a second roller of the pair of rollers.
The second frame structure is adjustable in a first direction toward the first roller and has a variable pivot position allowing the second frame structure to move in a second direction perpendicular to the first direction. The second frame structure also includes a pivot connection that allows the frame to move in the first direction. A biasing member such as a spring or actuator is connected to the second frame for biasing the second frame in the first direction.
In one embodiment, a series of openings into which the pivot connection connects allow the pivot connection to move in the second direction. In another embodiment, the second frame structure has a slot into which the pivot connection connects that allows the pivot connection to move in the second direction. In an additional embodiment, the second frame structure includes a screw mechanism to which the pivot connection connects, where adjustment of the screw mechanism allows the pivot connection to move in the second direction.
The first roller has a first axis about which the first roller rotates and the second roller has a second axis about which the second roller rotates. A reference line would connect the first axis and the second axis when the first roller and the second roller are not worn and are full size. The second direction would also be perpendicular to the reference line. Further, coordinated movement of the second frame in the first direction and the second direction keeps the second axis on this reference line as the size of the first roller and the second roller decrease because of wear.
An additional exemplary apparatus herein comprises a nip structure that includes a pair of rollers that form a nip. The rollers rotate in opposite directions to cause the sheets of media to move along a media path. Additionally, a first frame structure supports a first roller of the pair of rollers. The first frame structure can be in a fixed position and holds the first roller in a fixed location. A second frame structure supports a second roller of the pair of rollers.
The second frame structure is adjustable in a first direction toward the first roller and has a variable pivot position allowing the second frame structure to move in a second direction perpendicular to the first direction. The second frame structure also includes a pivot connection that allows the frame to move in the first direction. A biasing member such as a spring or actuator is connected to the second frame for biasing the second frame in the first direction.
In one embodiment, a series of openings into which the pivot connection connects allow the pivot connection to move in the second direction. In another embodiment, the second frame structure has a slot into which the pivot connection connects that allows the pivot connection to move in the second direction. In an additional embodiment, the second frame structure includes a screw mechanism to which the pivot connection connects, where adjustment of the screw mechanism allows the pivot connection to move in the second direction.
The first roller has a first axis about which the first roller rotates and the second roller has a second axis about which the second roller rotates. A reference line would connect the first axis and the second axis when the first roller and the second roller are not worn and are full size. The second direction would also be perpendicular to the reference line. Further, coordinated movement of the second frame in the first direction and the second direction keeps the second axis on this reference line as the size of the first roller and the second roller decrease because of wear.
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:
One exemplary nip structure that can be used within printing devices is illustrated in
The frame member 112 pivots around an axle, pin, or pivot point 114 such that the biasing member 110 causes of the roller 118 to be biased toward the feed roller 102. The axle 114 is generally a low friction cylindrical item that has sufficient strength to support the forces experienced by the frame 112 and can comprise a metal, alloy, plastic, etc. item (any may comprise rolling surfaces, such as roller or ball bearings, etc.). The rotation of the rollers 102, 118 through the nip area causes each sheet of media 106 to be propelled from the sheet storage 120 at a controlled speed along the paper path 100 toward the next item within the printing device that will perform an operation on the sheet of media 106.
As shown in
Thus, the nip angle varies over the life of the nip as the opposing rollers wear and their diameters are reduced, which can cause the issues that are mentioned above. In order to address these issues, as shown in
More specifically, as shown in
The second frame structure 112 is adjustable in a first direction toward the first roller 102 and has a variable pivot position to compensate for the arc movement the second roller 118 would experience with a single pivot position (
With the structure illustrated in
In an additional embodiment, the position of the first frame structure 104 can also be adjustable as illustrated by the downward arrow in
In another embodiment, illustrated in
In an additional embodiment illustrated in
Therefore, as shown above, with embodiments herein, the pivot point 114 on the second frame member 112 that is connected to the retard roller 118 can be automatically or manually changed to provide coordinated movement of the second frame in the first direction and the second direction to keep the second axis on or near (within a predetermined distance of) the reference line A-A as the size of the first roller 102 and the second roller 118 decrease because of wear. Further, the first frame member 104 can be adjusted manually or automatically
While the foregoing examples provide a nip that is positioned directly adjacent to the sheets storage area 120, those ordinarily skilled in the art would understand that any of the nips within the printing apparatus could utilize the dynamically positioned pivot point frame to avoid the issues that are caused by increasing separation nip angle, which occurs as the diameters of the nips decreased with wear.
Additionally, different structures, such as the biasing member 110 can be located in different positions. For example, as illustrated in
Further, the printing device 900 includes at least one accessory functional component (such as a scanner/document handler 904, sheet supply 120, finisher 908, etc.) and graphic user interface assembly 906 that also operate on the power supplied from the external power source 928 (through the power supply 922).
An input/output device 926 is used for communications to and from the multi-function printing device 900. The processor 924 controls the various actions of the printing device. A computer storage medium 920 (which can be optical, magnetic, capacitor based, etc.) is readable by the processor 924 and stores instructions that the processor 924 executes to allow the multi-function printing device to perform its various functions, such as those described herein.
Thus, a printer body housing 900 has one or more functional components that operate on power supplied from the alternating current (AC) 928 by the power supply 922. The power supply 922 connects to an external alternating current power source 928 and converts the external power into the type of power needed by the various components.
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.
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.