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(11) | EP 1 076 271 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Toner cartridge |
| (57) A cartridge for the replenishment of dry toner in an image forming apparatus, such
as a copier or printer, has a cylindrical container and a mechanism to move toner
uniformly toward a discharge opening for delivery to a toner storage region of the
image forming apparatus. As the container is rotated about its longitudinal axis,
a slidable wall rotates with respect to the container or a stationary threaded center
rod or lead screw. The slidable wall then translates itself down the lead screw, axially
displacing itself and displacing toner or developer into the storage region of the
image forming machine. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to electrophotographic imaging machines in general, and specifically to a cartridge for the delivery and replenishment of dry powder toner to be used by such an imaging machine.
2. Background
[0002] Devices for replenishing the toner in an electrophotographic or dry-toner type imaging device are known in the art. Generally, in such imaging devices, dry toner is supplied from a storage region to an imaging drum or film, where it is subsequently transferred to the image carrier and fused thereto to form a permanent image. As the supply of toner becomes depleted after repeated images are formed, it becomes necessary to replenish the supply.
[0003] The prior art contains many examples of the types of arrangements that are presently used for replenishing dry toner in imaging devices. For example, the replenishing supply of toner can be in the form of a relatively simple container having a spout which mates to a storage region of the imaging device, and the toner might be dumped by gravity into the storage region.
[0004] U.S. Patent 4,878,603 to Ikesue et al. describes an arrangement wherein replenishing toner is supplied in a cylindrical cartridge, one end of which contained a discharge opening. A removable gear was attached to the discharge end of the cylinder, the gear having teeth about its periphery. By attaching the gear and cartridge combination to a replenishment mechanism of the imaging device, the gear teeth of the cartridge was matable with a drive sprocket, which when activated rotated the toner replenishment cartridge about its longitudinal axis. A spiral guide rib raised on the inside surface of the cylindrical cartridge aided to feed the powder toward the discharge end of the cartridge and into the replenishment mechanism of the imaging device.
SUMMARY OF THE INVENTION
[0006] The present invention provides a toner cartridge comprising an elongated container having a longitudinal axis, an open end and a closed end. An end cap is adapted and arranged to close the open end of the container and to accommodate relative rotational motion between the elongated container and the end cap. A rod is fixedly attached to the end cap and extends substantially along the longitudinal axis. A slidable member is engaged with the rod and has a diameter adapted to engage the longitudinal wall of the container to provide circumferential movement between one of the rod or the longitudinal wall resulting in axial movement of the slidable member. Upon the relative rotation of the end cap and the elongated container, the slidable member travels along said rod to translate the interior volume of the container. When the cartridge is filled with toner, the structure provides for the uniform and positive displacement of replenishing toner from a cartridge to an image forming device without waste.
[0007] In an exemplary embodiment, the cartridge comprises an elongated cylindrical container filled with toner. The container has a longitudinal axis, an open end and a closed end. An end cap is adapted and arranged to close the open end and to accommodate relative rotational motion between the container and the end cap. A threaded rod is fixedly attached to the end cap and extends substantially along the longitudinal axis of the container. A wall member or plate is positioned on and threadedly engaged with the threaded rod and has a diameter to frictionally engage the cylindrical wall of the container to avoid circumferential movement therebetween. Upon relative rotation of the end cap and the elongated container, the plate or wall member is induced to travel longitudinally along the threaded rod to translate the interior volume of said container.
[0008] In further accord with the invention is a toner cartridge that in use provides a positive indication of the present status of the amount of toner remaining and, when empty, that its contents have been fully dispensed.
[0009] The invention further provides a toner cartridge that is easily mounted to and detached from a toner replenishment mechanism of an image forming machine.
[0010] Other objects, advantages and features of the invention will become apparent in view of the following detailed description and in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIG. 1 shows a cross-sectional view of an exemplary embodiment of a toner cartridge in accord with the invention.
FIG. 2 is an end view illustrating the end cap.
DETAILED DESCRIPTION OF THE INVENTION INCLUDING PREFERRED EMBODIMENTS
[0012] Referring to FIG. 1, there is shown an exemplary embodiment of the instant invention formed of a cartridge for uniformly and positively delivering replenishment toner to an image-forming device.
[0013] The toner cartridge 10 is comprised of a cylindrical container 4 defined by a smooth walled body portion which terminates at one end in a closed transverse wall 12 and terminates at an opposite end in an open mouthed configuration. Container 4 near its open end includes one or more radially outward projecting annular rims. The container is typically formed of plastic. Preferably, a clear plastic is used. Suitable plastic materials include, for example, polyethylene, polypropylene, polyethylene terephthalate, polybutadiene, and the like, etc.
[0014] A drive gear 5 is attached to the outside surface of the container, preferably retained along the axial dimension by at least one of the annular rims. The drive gear takes the general form of an annulus and is mounted so that an inside diameter of the gear annulus engages the container's outside diameter to rotate the container when the gear is driven. When engaged, the fit should allow rotation of container by the drive gear without any relative slippage. Preferably, the gear is fixedly attached to the container wall. More preferable, the gear is formed integrally with the container wall.
[0015] End cap 6 is mounted on the open end of the cartridge container 4. One or more annular rings on the container wall engage with the end cap to hold the end cap to the container. The end cap has an opening for the discharge of toner from the interior of the container 4 to the toner replenishment mechanism of an image-forming machine when in use to replenish toner.
[0016] When the cartridge is mounted to the toner replenishment mechanism of an image-forming machine, the end cap 6 of the toner cartridge of the exemplary embodiment of the instant invention is held stationary due to engagement of portion 16 of the end cap with the toner replenishment mechanism, and the drive gear 5 is matingly received by a powered sprocket of the replenishment mechanism or of the image forming apparatus. This arrangement allows for the discharge opening of the end cap (6) to remain fixedly oriented, while the container is rotated about its longitudinal axis by the powered sprocket. The end cap can be made of any suitable material, but preferably is made of a plastic material. Materials useful for the cartridge are also useful for the end cap.
[0017] A seal is typically provided between the end cap and the container. In this embodiment, a layer 13 of a polyurethane foam or a felt is attached to the inside of the end cap. When the end cap is mated with the container, the cylindrical wall of the container abuts the seal. Other materials suitable for sealing can also be used, as is well known to those skilled in the art of sealing moving components. Alternatively, a cylindrical seal can be provided between the cylindrical wall of the container and the cylindrical portion of the end cap. For example, a rotary seal can be provided between the periphery of the container and the end cap, as described in U.S. Patent No. 5,879,307.
[0018] Attached to the end cap 6 is a lead screw 3, which extends substantially down the longitudinal axis of the cartridge assembly and the container 4. The lead screw 3 is fixedly secured to the end cap 6 such that it remains stationary with the end cap 6. The screw can be made of a suitable metal or plastic material.
[0019] Mounted on the lead screw 3 is a disk-shaped slidable wall member 2, which is of substantially the same diameter as that of the inside of the container 4. The slidable wall member 2 has an internal thread that mates with the lead screw for translational movement along the longitudinal axis. The wall member divides the container into two chambers, one on either side of the slidable wall. Preferably, a resilient strip of material 1 is positioned on the circumference of the slidable wall member to frictionally engage the inside surface of the container wall. The strip 1 creates a seal between the two chambers formed in the container 4. The strip can be made of foam, an elastomeric material, or any material that frictionally engages the cartridge wall to avoid circumferential slipping motion therebetween.
[0020] In use, as the container 4 is rotated by the drive gear 5 through the action of a powered sprocket of the image forming machine, the frictional engagement between the strip 1 and the slidable wall member 2 will not rotate but will advance longitudinally along the lead screw. Thus, rotation of the container relative to the end cap will force the slidable wall 2 to move along the threads on the lead screw 3, resulting in the axial translation of the slidable wall 2. When the container is rotated in the proper direction and speed, the slidable wall will translate toward the open end closed by the end cap 6, uniformly displacing the contents of the container 3 through the opening 15 in the end cap 6 and into the toner replenishment mechanism of the image forming machine.
[0021] It can be appreciated that any material of sufficient rigidity, such as metal or plastic, can be used to form the container, gear, end cap, slidable wall member and lead screw, and that the strip may be formed of any material allowing sufficient frictional engagement with the inside surface of the container to allow the wall member to rotate along with the container, but not so much friction as to interfere with the axial translation of the slidable wall along the lead screw.
[0022] It can be appreciated that, although a lead screw is described as a part of the exemplary embodiment, a simulated threaded rod such as a center rod wrapped with a spring may be used to provide the threads for the slidable wall to traverse. Alternatively, rotation of the disk and resulting axial movement thereof can be achieved by suitable, e.g., threaded, engagement of the periphery of the disk with the cylindrical wall of the cartridge.
[0023] In further accord with the invention, preferably a window or other transparent region can be provided in an opaque container to allow visual confirmation of complete or progressing dispensation of replenishing toner. Preferably, the cartridge wall transmits enough light to locate the position of the slidable wall.
[0024] Although the above description refers to the dispensation of toner, it can be appreciated that the cartridge assembly of the present invention could be used to store, transport and dispense developer or other pulverulent chemicals or substances for various purposes.
[0025] Further, it is foreseen that the drive gear 5 can comprise a high friction gripping material, such as rubber, located between the gear ring and the outside surface of the container.
[0026] It is further foreseen that the end cap can contain a sloping surface extending into the interior of the container and defining an angle with respect to the longitudinal axis of the container to aid toner flow and possibly avoid compaction of the toner as the slidable wall translates toward the end cap.
[0027] Although the exemplary embodiment is described as being cylindrical, it is appreciated that different cross-sectional shapes for the container can be employed. Indeed, containers having corners can avoid rotational movement between the container and slidable wall member due to geometry. Alternatively, the rod can be square and the container cylindrical to avoid rotational movement about the rod.
[0028] Although the exemplary embodiment comprises a slidable wall which is described as being disk-shaped, it is foreseen that different shapes for the slidable wall can be employed, especially in the case where a cross section other than circular describes the container.
[0029] Finally, although the exemplary embodiment describes the lead screw as stationary, it is foreseen that it can be rotated while the container is maintained in a stationary orientation to accomplish a similar result.
[0030] Although the invention has been shown and described in detail with reference to preferred embodiments thereof, it can be appreciated that those skilled in the art, upon consideration of the disclosure including the drawings, may make various changes, additions and omissions in the form and detail thereof without departing from the spirit and scope of the invention, as defined by the claims.
1. A toner cartridge (10) comprising:
an elongated container (4) having a longitudinal axis, a wall, an open end and a closed end;
an end cap (6) adapted and arranged to close said open end and to accommodate relative rotational motion between the elongated container (4) and the end cap (6);
a rod fixedly attached to said end cap (6) and extending substantially along said longitudinal axis; and
a slidable member (2) mounted on and engaged with said rod and having a diameter adapted
to engage the wall of the container (4), the slidable member (2) being configured
and arranged to provide circumferential movement between one of the rod or the wall
resulting in axial movement of the slidable member;
wherein, upon the relative rotation of the end cap (6) and the elongated container
(4), said slidable member (2) travels longitudinally along said rod to translate the
interior volume of said container (4).
2. The toner cartridge of claim 1, wherein said rod is a threaded rod (3) and/or wrapped
by a spring.
3. The toner cartridge of claim 1 or 2, wherein said wall of the container (4) and said
slidable member (2) comprise mating surfaces and circumferential movement therebetween
provides axial translation of the slidable member (2) in the container (4).
4. A toner cartridge (10) comprising:
an elongated container (4) containing a quantity of toner and having a longitudinal axis, an open end and a closed end;
an end cap (6) adapted and arranged to close said open end and to accommodate relative rotational motion between the elongated container (4) and the end cap (6);
said end cap (6) further comprising an opening (15);
a lead screw rod fixedly attached to said end cap (6) and extending substantially
along said longitudinal axis; and a slidable wall (2) positioned on and threadedly
engaged with said lead screw (3) and having an outer diameter to frictionally engage
the container (4) to avoid circumferential movement therebetween;
wherein the quantity of toner is between said slidable wall (2) and said end cap (6)
and, upon the relative rotation of the end cap (6) and the elongated container (4),
said slidable wall (2) is induced to travel along said lead screw (3) to translate
the interior volume of said container (4) and deliver said quantity of toner through
said outlet (15) in said end cap (6).
5. The toner cartridge of one of claims 1 to 4, wherein said elongated container (4)
is substantially cylindrical and/or said slidable wall (2) is substantially disk-shaped.
6. The toner cartridge of one of claims 1 to 5, further comprising a drive gear (5),
preferably selectably removably attached to the outside circumference of said elongated
container (4) and/or substantially annular in shape.
7. The toner cartridge of claim 6, further comprising a gripping material interposed
between the drive gear (5) and the outside circumference of said elongated container
(4).
8. The toner cartridge of one of claims 1 to 7, further comprising a strip of resilient
material (1) located on the periphery of the slidable member or wall (2), respectively,
and contacting the container wall, wherein said strip (1) preferably is comprised
of foam or an elastomer.
9. The toner cartridge of one of claims 4 to 8, wherein said lead screw (3) comprises
a threaded rod and/or wrapped in a spring.
10. The toner cartridge of one of claims 1 to 9, further comprising a window configured
and arranged such that the position of the slidable member or wall (2), respectively,
within said elongated container may be visualized or determined, respectively.
11. The toner cartridge of one of claims 1 to 10, wherein said elongated container (4)
is formed of light transmitting material configured and arranged such that the position
of the slidable member or wall (2), respectively, within said elongated container
(4) may be visualized and/or determined.
12. A method for replenishing toner in an imaging machine comprising the steps of:
A) providing a toner cartridge (10) comprising:
an elongated container (4) containing a quantity of toner and having a longitudinal axis, an open end and a closed end;
an end cap (6) adapted and arranged said open end and accommodate relative rotational motion between the elongated container (4) and the end cap (6);
said end cap (6) further comprising an opening (15);
a rod fixedly attached to said end cap (6) and extending substantially along said longitudinal axis; and
a slidable wall (2) mounted on and engaged with said rod and having a diameter to engage the wall of the container (4), the slidable member (2) being configured and arranged to provide circumferential movement between one of the rod or the wall resulting in axial movement of the slidable member (2); and
B) imparting relative rotation between the end cap (6) and the elongated container (4) such that said slidable wall (2) is induced to travel along said rod to translate the interior volume of said container (4) and deliver said quantity of toner through said opening (15) in said end cap (6).
13. The method of claim 12, wherein said step of imparting relative motion comprises the
steps of rotating said elongated cartridge (4) and retaining said end cap (6) in a
substantially stationary position or the steps of retaining said elongated cartridge
(4) in a substantially stationary position and rotating said end cap (6).
14. The method of claim 12 or 13, wherein said providing step further comprises providing
a drive gear (5), preferably providing a selectively removable drive gear (5).
15. The method of one of claims 12 to 14, further comprising providing a container (4)
made of a light transmitting material and visually observing the position of said
slidable wall (2) inside the elongated container (4).