FIELD OF THE INVENTION
The present invention relates to seals which may be used in an image forming apparatus. The seals may prevent the leakage of image forming materials, e.g., as between a doctor blade and a component in the image forming device. The image forming apparatus may include an electrophotographic device, ink printer, copier, fax, all-in-one device or multi-functional device
BACKGROUND OF THE INVENTION
An image forming device, 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. The image fixing apparatus may also include a nip through which the media may be passed. The nip may be formed by a heater opposing a pressure roller. A belt or film may be included in the fixing device, in proximity to the heater to aid the transport of media through the fixing device nip.
SUMMARY OF THE INVENTION
In an exemplary embodiment the present invention relates to a sealing member for an image forming apparatus. The sealing member may utilize non-woven material. The apparatus may include a housing, a roller having a length and a blade extending along the length of the roller. The sealing member may partially overlap an end of the blade and locate between the housing and the blade. The sealing member may be used in a cartridge placed within the image forming apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut away schematic view inside an exemplary housing with the roller removed illustrating an exemplary seal.
FIG. 2 is a cut away schematic view inside the exemplary housing with the exemplary roller in place below a blade.
FIG. 3 is a sectional view of an exemplary blade assembly and exemplary seals without the roller present
FIG. 4 is a schematic view showing the placement of the exemplary seal of the present invention in relation to the exemplary roller and exemplary blade in an exemplary housing.
FIG. 5 is an enlarged side view of the exemplary end seal according to the present invention.
FIGS. 6
a-6c are cross-sectional views of an exemplary blade and roller.
FIG. 7 is a schematic view of a blade and an end seal positioned at one end.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to seals which may be used in an image forming apparatus. The seals may prevent the leakage of image forming materials, e.g. as between a blade and a housing in the image forming apparatus. The blade may be a “doctor blade” which may control the thickness of image forming material on a given surface, such as a roller surface. The image forming apparatus may include an electrophotographic device, ink printer, copier, fax, all-in-one device or multi-functional device.
With reference first to FIG. 4, an exemplary blade component (10e) is illustrated that may therefore be disposed adjacent a roller (10d) to regulate the thickness of image forming substance formed therebetween. The exemplary blade (10e) (see FIG. 4) may be cantilevered (supported on one side) by a pair blade support members (20a), (20b) such that the lower surface of the blade (10e) may be tangential to the surface of the developer roller (10d). FIG. 4 illustrates the blade (10e) viewed prior to engagement with a first housing (12). FIG. 2 illustrates the blade (10e) assembled with the housing (12). The blade may be relatively flat and may also include a portion that extends beyond the tangent point location with the roller. This may be illustrated with reference to FIG. 6a which shows in cross-section blade (10e) in tangential engagement with roller (10d) and tangent point location (30). As can be see, the blade may include a portion (10e1) that extends beyond the illustrated tangent point.
The blade support members (20a), (20b) are further illustrated in FIG. 4. The lower member (20a) and upper member (20b) may cooperate to clamp the blade (10e). The support members may be metal or plastic. The blade (10e) may comprise metal or plastic and may therefore be formed from stainless steel. The blade may have a thickness of about 0.005-0.010 inches and all values and increments therebetween. The blade may also include a flange (see 10e1 in FIG. 4) along one edge. The flange may be upturned relative to the roller 10d. The assembly (members (20a), (20b), and blade (10e) may be located and fastened to the housing (12) using a locator pin (26) and hole (27) (to receive a screw, not shown) as shown in FIG. 1. The assembled condition with roller (10d) in place is shown in FIG. 2.
FIG. 3 illustrates the blade (10e) extending from the support members (20a) and (20b) while FIG. 4 illustrates the blade (10e) in an assembled condition bearing against the surface of the roller (10d) which may deflect the blade (10e) upward. That is, the roller (10d) may serve to deflect the blade upward against end seal (24) and back seal (22). The end seal (24) may therefore overlap a portion of the end 40 of the blade (10e) and may be held in place by the housing (12). With reference to FIG. 7, a general location of the end 40 of the blade 10e may be illustrated. On the right hand side of the blade 10e the end seal is illustrated in draft and as can be seen, it may overlap a portion of the end 40 of blade 10e. The end seal may be formed of any material which may reduce the amount of image forming material from passing as between, e.g., the end seal and housing.
The amount of force which the cantilevered blade (10e) may apply to the roller (10d) may also be varied and may therefore be adjusted by the relative positions of support members (20a) and (20b) (see FIG. 3). For example, support member (20b) may extend beyond (20a) or (20a) may extend beyond (20b). In such latter exemplary case (support member 20b extending beyond support member 20a) the relative force on the blade will be increased.
FIG. 1 is a view looking into the housing (12) with the developer roller removed. The end seal (24) may therefore be positioned as shown into the housing and may be engaged with the housing by use of an adhesive. In addition, a curved J-seal (16) may be supplied. Therefore, in FIG. 1, with the roller (10d) and blade 10(e) removed, one can see the combination of J-seal (16), separate end seal (24) and back seal (22). The curved J-seal (16) (FIG. 2) may therefore be provided to seal the roller (10d) to a C-shaped portion of the housing (12). This J-seal may generally comprises a relatively flexible and relatively low modulus material such as urethane, artificial rubber or fluorocarbon polymer having a Shore A hardness of from about 55 to about 75. The back seal (22) (see both FIGS. 1 and 4) may therefore seal along the length of the blade (10e) and against the housing (12) (FIG. 1). This may further prevent leakage of image forming material with respect to, e.g., the blade and housing.
It can therefore be appreciated that a gap may exist between the back seal (22) and J-seals (16) when a cantilevered blade (10e) tangentially engages the roller (10d). As illustrated in FIG. 4 the end seal 24 may fill such gap. As alluded to above, the end seal (24) may also be compressed between the housing (12) (see FIG. 1) and the blade (10e) (see FIG. 4) by the roller 10(d). The end seals (24) may also abut a rotary seal portion such as a J-seal (16) as well as a back seal (22) as shown in FIGS. 3 and 4.
In addition, where a “checkmark” blade is employed with flange running along all or a portion of the blade edge, the flange may be an upstanding flange (10e1) relative to the roller. The flange may then be trimmed back to at or near the tangent point at the particular region wherein the blade may engage with the end seal. For example, with reference to FIG. 6a, the portion (10e1) may be trimmed back to at or near the tangent point location 30. This may be illustrated by FIG. 6b which shows portion 10e1 that is trimmed back more towards the tangent point location relative to what is shown in FIG. 6a to provide a sealing location. Furthermore, FIG. 6c provides another illustration where the portion 10e1 has been substantially trimmed back or removed which may also then provide a sealing location for the seal 24. It may therefore be the case that FIG. 6c illustrates an end portion of the blade where end seal 24 may seal as between the blade, roller and housing.
It can therefore be appreciated that the “checkmark” blade herein may include a portion (10el) that runs along the length of the blade having a first extending dimension (D1) beyond the contacting tangent point location 30 as shown in FIG.6a. Then, in the region where the blade may engage with the seal, the flange portion may be of a second dimension (D2), which second extending dimension is less than that of the first extending dimension as shown in FIG. 6b. In addition, in the region where the blade engages with the seal, the flange may be completely removed back to the tangent point as shown in FIG. 6c. Furthermore, and optionally, in those cases where the flange may not be trimmed back to the tangent point at the region of engagement with the end seal (24), the end seal at each end of the blade may include a slit to receive such flange or be made of a material that may receive the flange and form a slit.
The end seals (24) of the present invention may comprise a relatively low modulus polymeric type material with a flex modulus of less than about 200,000 psi. The ends seals may include 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 (24) to bear against the developer roller. This may be generally illustrated in FIG. 5 by reference numeral (25). As shown in FIG. 5, the exemplary seal (24) is presented in cross section, and may include a double-backed pressure sensitive adhesive tape (28a) to adhere the non-woven layer (25) to the foam (29). A second layer of tape (28b) may be used to adhere the foam (29) to the developer housing (12). In addition, the non-woven material for the seal (24) 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.
With reference to FIG. 5, it is also contemplated that the non-woven layer (25) may be adhered directly to the foam (29). For example, the foam layer itself may be one that during preparation thereof, affords a surface that may engage and adhere directly with the non-woven fibers. In addition, it is contemplated that the non-woven layer may be made to mechanically engage with the foam layer as a result of mechanical engagement of the non-woven fibers with, e.g., a course foam surface. In addition, it is contemplated that one may employ separate mechanical connectors.
For purposes of exemplification, various embodiments of the invention have been shown and described. However, it will be apparent that changes and modifications may be resorted to without departing from the spirit and scope of the invention.
Patent Grant
7561820
