Patent Application
20080170879
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1. Field of the Invention
The present invention relates to a seal within an image forming apparatus, and more particularly, to a roll seal that seals an interface between a developer roll and a developer frame.
2. Description of the Related Art
An image forming apparatus, such as an electrophotographic device, ink printer, copier, fax, all-in-one device or multi-functional device may use developing agents such as toner or ink, which may be disposed on media to form an image. The developing agent, such as toner, may be fixed to the media using an image fixing apparatus, which may apply heat and/or pressure to the toner. In a developer assembly in an image forming apparatus, there is a desire to seal the interface between the developer roll and the developer frame to prevent or minimize leakage of the developing agent. In conventional developer assemblies, the seals may not be adequate and may not stay in position as the developer roll rotates.
One exemplary embodiment of the present disclosure relates to a seal assembly for sealing an interface between a roller and a frame in an image forming apparatus. The seal assembly may include an end seal configured to seal a doctor blade in contact with the roller. The roll seal may include a sealing surface configured to seal at least a portion of an outer surface of the roller and an extension portion located between the end seal and the roller. The extension portion may have a reduced thickness or be tapered. In addition, the roll seal may include an end portion configured to engage the frame which upon engagement may provide a resistance in movement of the roll seal upon roller rotation.
Another exemplary embodiment of the present disclosure relates an assembly for sealing components in an image forming device which includes a frame and a roller rotatably mounted in that frame and having an outer surface. A blade may then be mounted with a portion of the blade in contact with the roller and at least one end seal positioned in the frame and configured to seal the blade to the roller. At least one roller seal may be located within the frame that may contact a portion of the outer surface of the roller, the roll seal including a sealing surface conforming to a portion of the outer surface of the developer roll, the roll seal including a first end located between the end seal and the roller.
Yet another exemplary embodiment relates to a roll seal for a frame and roller including a body portion and an arcuate sealing surface extending along a first side of the body portion configured to engage and seal a portion of the roller. At least one rib may be provide that extends along a second side of the body portion. The roll seal may include an end portion that is configured to engage the frame along with an extension portion. The extension portion may include a sealing surface wherein the extension portion may extend beyond the identified rib portion.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings wherein:
It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.
As alluded to above, the present disclosure relates to a roll seal and seal assembly for sealing an interface between a roller and a frame. The roller may include a developer roller and the frame may include a developer frame (as may be found in a laster printer) which may include a blade such as a doctor blade and an end seal for the doctor blade. While the disclosure herein is therefore described in such context, it should be appreciated that other configurations are contemplated. In addition, generally, the roll seal may engage and overlap an end seal at one end and may be secured against movement at the other end. The seal assembly may therefore be used, for example, in an image forming apparatus including, but not limited to, printers (e.g. a laser printer), copiers, faxes, multifunctional devices or all-in-one devices.
In one embodiment, the end seal 120 may seal the end of a blade 140 (e.g., a doctor blade) contacting a surface of the developer roll 130. Although only one end is shown, end seals 120 may be used at each end of the blade 140. In general, the blade 140 may be used to control the thickness of image forming material (e.g., toner) on a surface of the developer roll 130. The blade 140 may include a portion 142 mounted or clamped, for example, between blade support members 150, 152 such that another portion of the blade 140 contact the developer roll 130. The support members 150, 152, with the blade 140 clamped therebetween, may be secured to a developer frame (not shown). The blade 140 may be mounted such that the amount of force of the blade 140 may be varied, for example, by adjusting the relative positions of the support members 150, 152.
The end seal(s) 120 may be made of any material capable of reducing the amount of image forming material from passing the end seal(s) 120. In one example, the end seal(s) 120 may include a relatively low modulus polymeric type material with a flex modulus of less than about 200,000 psi. The end seals may include, for example, a relatively low density (about 4.0 to about 8.0 pounds per cubic foot) open-celled polyester urethane foam having a 25 percent Compression Load Deflection (CLD 25%) of about 0.6 (per ASTM D-3574-86). Other types of flexible foams such as polyether urethane, silicone or rubber may also be suitable. The end seals may also include or be composed of abrasion resistant material such as a non-woven material. An example of such non-woven material is a polyester ultra-microfiber non-woven with a non-fibrous polymeric binder such as a polyurethane binder. For example the non-woven material may be Ultrasuede® from Toray (Ultrasuede (America)), Inc., which may be adhered to the bottom surface of the end seals to bear against the developer roller. In addition, the non-woven material for the end seals may have a basis weight of about 100-1000 g/m2, a denier of about 0.01-0.2, a thickness of about 0.1-5.0 mm and a surface abrasion resistance (ASTM D3886 P800) of about 100-10,000, and values greater than 10,000, including all ranges and values between 100-10,000.
One example of the blade 140 is a cantilevered “checkmark” doctor blade. The blade may be made of a metal (e.g., stainless steel) or a plastic material and may have a thickness of about 0.005-0.010 inches. If the blade 140 is a “checkmark” doctor blade, a portion of the blade 140 may contact the developer roll 130 at a tangential contact point and a portion of the blade 140 may extend away from the tangential contact point. At the ends of the blade (e.g., one end is shown in
Referring to the enlarged view in
As shown in
One embodiment of the roll seal 110 may be similar to the type known as a J-seal. The J-seal may include a relatively flexible and relatively low modulus material such as urethane, natural or synthetic rubber (e.g., cis-polyisoprene) or fluorocarbon polymer having a Shore A hardness of greater than or equal to about 55, and more specifically, having a value of about 55-110, as well as all values and increments therein. The sealing surface 114 may also include grooves known to those skilled in the art for use on J-seals. Those skilled in the art will recognize that other shapes and configurations may be used for the roll seal.
The roll seal 110 may also include at least one rib 118 (sometimes referred to as compression ribs) on the side of the roll seal 110 opposite the sealing surface 114. The rib(s) 118 may extend from the toe portion 117 to the extension 113 such that the rib(s) 118 contact the end seal 120 (see
Referring to
The toe portion 117 may be positioned within a slot 620 of the developer frame 610. The slot 620 may include surfaces or portions 622, 624 that engage surface or portions 162, 164 of the toe portion 117 to constrain the toe portion 117 within the developer frame 610. Thus, the roll seal 110 may engage and become relatively immobilized in the developer frame 610. In one embodiment, only the toe portion 117 is engaged into the developer frame 610, allowing the remainder of the roll seal 110 to stretch in the direction of rotation of the developer roll 130.
The developer roll (not shown) may be rotatably mounted within a bearing portion 614 of the developer frame 610. When a developer roll, such as developer roll 130 shown in
The blade (not shown in
Thus, the developer frame 610 may receive and secure the roll seal 110, the end seal 120, the developer roll 130, and the blade 140, for example, in the interlocking relationship shown in
The foregoing description of several methods and an embodiment of the invention has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to precise steps and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. It is intended that th scope of the invention be defined by the claims appended hereto.
