Spring bearing for use in a developer cartridge roller system

The present disclosure is directed to a spring bearing which is used in a roller system for a developer cartridge. The spring bearing has a front surface and a rear surface and an angled relief cut extending from the front surface to the rear surface.

BACKGROUND

The present disclosure relates to a spring bearing which is used in a roller system in a developer cartridge.

Roller systems used in developer cartridges typically having a magnet roller which rotates during operation. Bearings are provided on opposite sides of the magnet roller to facilitate rotation of the magnet roller. These bearings have a short life span as a result of the stress forces created during rotation of the magnet roller. This necessitates frequent replacement of the roller systems.

It would be desirable to have a roller system with an extended life span.

SUMMARY

In accordance with the present disclosure, there is provided a spring bearing which broadly has a front surface and a rear surface and an angled relief cut extending from the front surface to the rear surface.

In another and alternative embodiment, the spring bearing may further have a first flat exterior surface on a first side and a second flat exterior surface located on a second side opposed to the first side.

In another and alternative embodiment, the angled relief cut may be angled with respect to the first and second flat exterior surfaces.

In another and alternative embodiment, the spring bearing may further have a front portion and a back portion and the front portion forms a lip with the back portion.

In another and alternative embodiment, the spring bearing may further have a foot extending from an outer surface of the back portion to one of the first and second flat exterior surfaces.

In another and alternative embodiment, the foot may have a constant thickness portion and two opposed arcuate portions adjacent the constant thickness portion.

In another and alternative embodiment, the spring bearing may further have an internal opening extending from the front surface to the rear surface.

In another and alternative embodiment, the internal opening may have a linear wall extending from the rear surface and an angled wall extending from the front surface and mating with the linear wall.

In another and alternative embodiment, the spring bearing may be formed from a material selected from the group consisting of nylon, acetal, polytetrafluoroethylene (PTFE), ultra high molecular weight polyethylene (UHMW) and IGUS® IGLIDE® J plastic material.

Further in accordance with the present disclosure, there is provided a roller system for a developer cartridge which broadly comprises a magnet roller, a magnet roller sleeve surrounding the magnet roller, a first bushing abutting the magnet roller sleeve, and a first spring bearing abutting the first bushing, the first spring bearing having a front surface and a rear surface and an angled relief cut extending from the front surface to the rear surface.

In another and alternative embodiment, the roller system may further comprise a first endpiece adjacent the first spring bearing and the first spring bearing mating with the first endpiece.

In another and alternative embodiment, the roller system may further comprise the first spring bearing having a first flat exterior surface on a first side and a second flat exterior surface on a second side opposed to the first side.

In another and alternative embodiment, the roller system may further comprise the first endpiece having a flat surface and one of the first and second flat exterior surfaces being aligned parallel to the flat surface of the first endpiece.

In another and alternative embodiment, the roller system may further comprise the first endpiece having an opening and a notch adjacent the opening and the first spring bearing having a foot which fits into the notch.

In another and alternative embodiment, the roller system may further comprise the first spring bearing having a front portion and a back portion and the back portion fitting in the opening in the first endpiece.

In another and alternative embodiment, the first spring bearing may have a lip formed by the front portion and the lip abutting the first endpiece.

In another and alternative embodiment, the roller system may further comprise a drive gear for driving the magnet roller and the drive gear may be housed in an exterior portion of the first endpiece.

In another and alternative embodiment, the roller system may further comprise an outer endpiece abutting the drive gear.

In another and alternative embodiment, the roller system may further comprise a hopper magnetic roller assembly having an arcuate portion for housing the magnet roller with the magnet roller sleeve.

In another and alternative embodiment, the roller system may further comprise a doctor blade and a sealing blade attached to the hopper magnetic roller assembly.

In another and alternative embodiment, the roller system may further comprise a second bushing abutting a second end of the magnet roller sleeve, a second spring bearing abutting the second bushing, and a second endpiece mating with the second spring bearing.

In another and alternative embodiment, the roller system may further comprise each of the first and second spring bearings being formed from a material selected from the group consisting of nylon, acetal, polytetrafluoroethylene (PTFE), ultra high molecular weight polyethylene (UHMW), and IGUS® IGLIDE® J plastic material.

Other details of a spring bearing for a toner cartridge roller system are set forth in the following detailed description and the accompanying drawings, wherein like reference numerals depict like elements

DETAILED DESCRIPTION

Referring now to the drawings,FIGS. 1 and 2illustrate a roller system10which may be used in a developer cartridge used in a printing and/or copying machine. The roller system10may include a hopper magnetic roller assembly12, a doctor blade14, a magnet roller sleeve16, and a sealing blade18. The doctor blade14may have a wiper tab20located on each side of the doctor blade14for securing the doctor blade14to the hopper magnetic roller assembly12.

The roller sleeve16may have a bushing22which abuts the roller sleeve16at side ends17and19. A spring bearing24may be positioned adjacent each of the bushings22. A drive gear26may be positioned on one side of the roller sleeve16for driving the roller sleeve16and the magnetic roller32located therein. The drive gear26may be connected to any suitable drive system known in the art. The roller system10further includes inner endpieces28and30which house the spring bearings24and an outer endpiece31which houses the drive gear26. The inner endpieces28and30and the outer endpiece31may be secured to the hopper magnetic roller assembly12using any suitable fastening/securing devices known in the art.

As can be seen fromFIG. 2, the magnetic roller sleeve16surrounds an internal magnetic roller32. The roller sleeve16is positioned within an arcuately shaped portion34of the hopper magnetic roller assembly12. The bushings22are positioned on the ends36of the roller sleeve16so as to abut the roller sleeve16. The spring bearings24are then positioned adjacent the bushings22. The bushings22and the spring bearings24may be secured in place by one of the inner endpieces28and30which may be secured to the hopper magnetic roller assembly12by a suitable fastener such as screws/bolts38. The drive gear26may then be positioned within an outer portion40of the inner endpiece28. The outer portion40may have an arcuately shaped opening41for receiving the drive gear26. The drive gear26may be connected to the magnetic roller32and the magnetic roller sleeve16so as to rotate the magnetic roller32and the surrounding roller sleeve16. The outer endpiece31covers the drive gear26and secures the drive gear26in position relative to the hopper magnetic roller assembly12. The outer endpiece31may be fastened or otherwise connected to the outer portion40of the inner endpiece28. The inner endpiece30may be used to secure the bushing22and the spring bearing24in position on the opposite side36of the magnetic roller sleeve16.

FIG. 3illustrates one of the spring bearings24positioned within one of the inner endpieces28and30. As can be seen fromFIG. 3, each of the spring bearings24has a spring relief cut50. The spring relief cut50is located between two flat surfaces52and54. The flat surface52is aligned parallel with a flat surface56on the inner endpiece28,30.

FIG. 4is an exploded view of the spring bearing/end piece arrangement ofFIG. 3. The endpiece28,30has an opening60into which a back portion66of the spring bearing24fits. The opening60includes a notch62in which a foot64on the spring bearing24is positioned so that the surfaces52and56align parallel to each other.

As can be seen inFIG. 5, each spring bearing24has a back portion66which is shaped and dimensioned to fit within the opening60. Each spring bearing24has a front portion68which has a larger outer dimension than the outer dimension of the back portion66so as to form a lip70which abuts the sidewall72of the endpiece28,30surrounding the opening60. As can be seen fromFIG. 6, the spring relief cut50extends from the front surface74of the front portion68to rear surface76of the back portion66. It also extends from the outer surfaces of the front portion68and the back portion66to an internal opening82.

A copper contact78may be secured to one of the inner endpieces28,30. The copper contact is for the magnetic roller32. The copper contact78receives an AC/DC signal that is applied to the magnetic roller32which helps improve the contrast and which will add more or less toner to be attracted to the drum. This is typically controlled by the printer's density setting.

FIG. 7is a perspective view of the spring bearing24including the spring relief cut50, the foot64, the flat surface54, the front portion68, the back portion66, the lip70, and the rear surface76.

Referring now toFIG. 8, which illustrates a rear view of the spring bearing24, the spring relief cut50is angled with respect to the axis80which extends parallel to the flat surfaces52and54. The angle a may be in the range of 15 to 20 degrees. The foot64may extend from an outer surface67of the back portion66to the flat surface54and may be formed with a constant thickness portion90and two opposed arcuate shaped portions92adjacent the constant thickness portion90. The notch62, as shown inFIG. 5, may be configured or shaped to have a shape which is receptive to the foot64. The spring bearing24further has an internal opening82.

FIG. 9is a sectional view of the spring bearing24taken along lines9-9inFIG. 8. As can be seen fromFIGS. 9 and 10, the spring bearing24includes an internal opening82which extends from the front surface74of the front portion68to the rear surface76of the back portion66. The internal opening82may be defined by a linear inner wall section84and an adjacent angled wall section86which mates with the linear inner wall section84. If desired, the back portion66may have an angled outer wall section89. As can be seen fromFIGS. 9 and 10, the spring bearing24may be formed as a unitary structure.

The spring bearing24may be formed from a material selected from the group consisting of nylon, acetal, polytetrafluoroethylene (PTFE), ultra high molecular weight polyethylene (UHMW), and IGUS® IGLIDE® J plastic material. The material forming the spring bearing24may posses the ability to handle high loads over an extended period of time. Further, the material may be characterized by a low coefficient of friction and low wear rates resulting in longer service life. The material forming the spring bearing24may be a plastic material consisting of base plastics, fibers and/or filling materials and one or more solid lubricants. These components may not be in layers, but rather homogeneously compounded. The advantages of such a construction is that: the coefficient of friction, determined by the surface of the plastic material, should be as low as possible; the surface may not be pushed aside by forces acting on the plastic material; and the plastic material should be particularly resistant to wear forces acting on its surface. The solid lubricant(s) may be embedded as microscopic particles in chambers in a fiber reinforced plastic material. From these chambers, the plastic material may release tiny amounts of solid lubricant during movement. Since the solid lubricant(s) is/are embedded in the chambers, they can not be pressed out. They are always there as soon as the plastic material is set in motion, thus helping to lower the coefficient of friction. Any radial pressure acting on the plastic material may be taken by the plastic base material, thus providing support at the contact surface. The plastic base material ensures that the solid lubricant(s) do not receive a surface pressure that is too high. The plastic base material may also be reinforced by fibers and/or filling materials. These additional materials help stabilize the plastic material for applications involving continuous stress.

The spring bearing24described herein should provide a number of advantages including (1) preventing banding due to the different radius on the hub of the magnetic rollers; (2) being greaseless (self lubricating); (3) having a low coefficient of friction; and (4) being reusable due to its low wear rate.

There has been provided in accordance with the present disclosure, a spring bearing which may be used in a toner cartridge roller system. While the spring bearing has been described in the context of specific embodiments thereof, other unforeseen alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, these alternatives, modifications, and variations are intended to be embraced by the broad scope of the following claims.