Cylindrical toner cartridge for electrophotographic printer

Abstract: A toner cartridge has an outer cylinder (2) and an inner cylinder (7) contained in the outer cylinder (2) in such a relation that it is adjucent to the outer cylinder (2) and slidable. An outer cylinder toner discharge opening (5) is provided on the outer cylinder in a longitudinal direction thereof. An inner cylinder toner discharge opening (9) is provided on the inner cylinder in a longitudinal direction thereof, the inner cylinder toner discharge opening (9) being to be engaged with the outer cylinder toner discharge opening (5). The opposite ends of the outer cylinder (2) are provided with notches (4), respectively. The outer cylinder toner discharge opening (5) is provided with at least one outer cylinder rib (6). The inner cylinder toner discharge opening (9) is provided with at least one inner cylinder rib (10), which is located in such a relation that it is not engaged with the outer cylinder rib (6). A toner cartridge is thereby provided which is excellent in slidability in the inner cylinder (7).

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a toner cartridge for an electrophotographic printer or the like, and more particularly to a toner cartridge comprising an outer cylinder and an inner cylinder which is slidably contained in the outer cylinder. Description of the Prior Art A conventional toner cartridge for an electrophotographic printer comprising an outer cylinder and an inner cylinder which is slidably contained in the outer cylinder, both having one opening for discharging the toner, is for example disclosed in JP-A-60 147 764 or in US-A-3 356 248. There is also known another kind of toner cartridge comprising an outer cylinder having outer cylinder apertures formed at both ends thereof, respectively, and an inner cylinder contained in the outer cylinder in such a relation that it is adjacent to the outer cylinder and slidable, which inner cylinder has inner cylinder apertures formed at opposite ends thereof, respectively. Such a toner cartridge is shown in FIGS. 8-12. As apparent from FIGS. 8 and 9, the toner cartridge is so arranged that an outer peripheral surface of an inner cylinder 7, including an inner cylinder rib 10, extended in a periphery direction and an inner peripheral surface of an outer cylinder 2, including an outer cylinder rib 6, extended in a periphery direction are formed on a sliding face over the whole periphery. Referring to FIGS. 9 and 10, inner cylinder toner discharge openings 9 are closed with an inner wall of the outer cylinder 2. Thus, a toner, not shown, filled up in the inner cylinder 7 is not discharged. If it is required to discharge the toner from an outer cylinder toner discharge openings 5, the inner cylinder 7 is rotatively slided to the outer cylinder 2 in an arrow direction A so that the inner cylinder toner discharge openings 9 are engaged with the outer cylinder toner discharge openings 5. If inner cylinder 7 is further rotatively slided to the outer cylinder 2 in the arrow direction A, the inner cylinder toner discharge openings 9 are engaged with the outer cylinder toner discharge openings 5, as shown in FIGS. 11-12, whereby there is obtained a full opened condition. In such a condition, an inner cylinder rib 10 is aligned with an outer cylinder rib 6. If it is required to close the inner cylinder toner discharge openings 9, the inner cylinder 7 is rotatively slided to the outer cylinder 2 in an arrow direction B so that the inner cylinder toner discharge openings 9 are closed with an inner wall of the outer cylinder 2. There is a problem with this arrangement of toner cartridge however. If the inner cylinder 7 or the outer cylinder 2 is deformed, it will be impossible to expect a smooth sliding motion between the outer peripheral surface of the inner cylinder 7 and the inner peripheral surface of the outer cylinder 2, and such a deformation will make occurrence of a galling owing to an interference therebetween. Further, the toner cartridge is so arranged that outer peripheral surfaces at both ends of the inner cylinder 7 and inner peripheral surfaces at both ends of the outer cylinder 2 are formed on a sliding face over the whole periphery. There is a problem with this arrangement of toner cartridge however. If the outer cylinder 2 is deformed, it will be impossible to expect a smooth sliding motion between the outer peripheral surfaces at both ends of the inner cylinder 7 and the inner peripheral surfaces at both ends of the outer cylinder 2, and such a deformation will make occurrence of a galling owing to an interference therebetween. Furthermore, the toner cartridge is so arranged that an edge portion 3a of the inner cylinder toner discharge openings 9 and an edge portion 5a of the outer cylinder toner discharge openings 5 are formed in a paralell relation. There is a problem with this arrangement of toner cartridge however. When the inner cylinder toner discharge openings 9 are closed, the respective edge portions are involved with each other. Thus, it would be impossible to close the inner cylinder toner discharge openings 9. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a toner cartridge which solves the foregoing problems. It is another object of the present invention to provide a toner cartridge which is excellent in slidability in the inner cylinder. The present invention is disclosed in claim 1. Claims 2 to 5 disclose particular embodiments thereof. BRIEF DESCRIPTION OF THE DRAWINGS The objects and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 is a perspective view of a preferred embodiment of a toner cartridge in accordance with the present invention; FIG. 2 is a partial cutway view taken in the direction of the arrows substantially along the lines I-I of FIG. 1; FIG. 3 is a transverse sectional view of the embodiment shown in FIG. 1; FIG. 4 is a partial cutaway view for explanation of the inner cylinder rib and the outer cylinder rib of the embodiment; FIG. 5 is a view for explanation of an inner cylinder toner dischage opening of the embodiment; FIG. 6 is a view for explanation of edge portions of the embodiment; FIG. 7 is a view for explanation of an outer cylinder toner dischage opening of the embodiment; FIG. 8 is a partial cutway view in perspective of a conventional toner cartridge; FIG. 9 is a transverse sectional view of the conventional toner cartridge shown in FIG. 8; FIG. 10 is a cross-sectional view taken on line II-II of FIG. 9; FIG. 11 is a transverse sectional view for explanation of a complete open state of the conventional cartrigde; and FIG. 12 is a cross-sectional view taken on line III-III of FIG. 11. DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a toner cartrige of the invention will be described with reference to FIGS. 1-3. In the figures, the like parts are denoted by the same reference numbers. A toner cartridge 1 is provided with an outer cylinder 2, which is generally cylindrical and hollow, and extends in its longitudinal direction, as shown. Both ends of the outer cylinder 2 are provided with outer cylinder aperture sections 3, respectively, and in addition a plurality of notches 4, respectively. Further, the outer cylinder 2 is provided with outer cylinder toner discharge openings 5 extending in the longitudinal direction thereof. The outer cylinder toner discharge opening 5 are provided with an outer cylinder rib 6 located substantially at the center thereof and extended in the periphery direction of the outer cylinder 2. An inner cylinder 7 is contained in the outer cylinder 2 in such a relation that it is adjacent to the outer cylinder 2 and slidable. The inner cylinder 7, which is also generally cylindrical and hollow, and extends in its longitudinal direction, similarly to the outer cylinder 2, is provided with inner cylinder aperture sections 8 at opposite ends thereof, respectively, each aligned with the associated one of the outer cylinder aperture sections 3. The inner cylinder is also provided with inner cylinder toner discharge openings 9 extending in a longitudinal direction thereof. The inner cylinder toner discharge openings 9 are provided with innner cylinder ribs 10 each located substantially at a distance from the associated one of the respective inner cylinder aperture sections 8 which is substantially equal to 1/4 length of the inner cylinder toner discharge openings 9 extending in the longitudinal direction thereof, the ribs extending in the periphery direction of the inner cylinder 7. In other words, these inner cylinder ribs 10 are located in such a relation that they are not engaged with the outer cylinder rib 6. A cover 11 is provided on one of the inner cylinder aperture sections 8, and a cover 11a is provided on another. The cover 11a is provided with a toner supply opening 12. A cap 13 is detachably mounted on the toner supply opening 12. In operation, if it is required to discharge a toner, not shown, filled up in the cavity of the inner cylinder 7, the inner cylinder 7 is rotatively slided to the outer cylinder 2 so that the inner cylinder toner discharge openings 9 are engaged with the outer cylinder toner discharge openings 5. If it is required to stop the discharge of the toner, the inner cylinder 7 is rotatively slided to the outer cylinder 2 so that the inner cylinder toner discharge openings 9 are closed with an inner wall of the outer cylinder 2. As shown in FIG. 4, it may be arranged that the inner cylinder rib 10 is provided at a place shifted into the right direction from the center of the the inner cylinder toner discharge openings 9, while the outer cylinder rib 6 is provided at a place shifted into the left direction from the center of the the outer cylinder toner discharge openings 5. As a matter of course, the outer cylinder rib 6 and the inner cylinder rib 10 are not restricted in their setting positions and the setting number as far as the outer cylinder rib 6 and the inner cylinder rib 10 are not aligned with each other on the same periphery. Further, as shown in FIG. 5, it is preferrable that an edge portion 9a of the inner cylinder toner discharge openings 9 at the side for sealing the toner is formed at angles with an edge portion 5a of the outer cylinder toner discharge openings 5. According to such an arrangement, when the inner cylinder toner discharge openings 9 are closed by means of rotatively sliding the inner cylinder to the outer cylinder 2, the edge portions 9a of the inner cylinder toner discharge openings 9 are slided to the edge portions 5a of the outer cylinder toner discharge openings 5 on a point contact basis, as shown in FIG. 6. Thus, it is possible to avoid such a situation that the edge portions 5a and 9a are involved with each other, whereby the inner cylinder 7 is smoothly slided to the outer cylinder 2 so that the inner cylinder toner discharge openings 9 are smoothly closed. Furthermore, as shown in FIG. 7, it is also preferable that the edge portions 5a of the outer cylinder toner discharge openings 5 at the side for sealing the toner are formed at angles with the edge portions 9a of the inner cylinder toner discharge openings 9. According to such an arrangement, when the inner cylinder toner discharge openings 9 are closed by means of rotatively sliding the inner cylinder 7 to the outer cylinder 2, the edge portions 5a of the outer cylinder toner discharge openings 5 are slided to the edge portions 9a of the inner cylinder toner discharge openings 9 on a point contact basis. Thus, it is possible to avoid such a situation that the edge portions 5a and 9a are involved with each other, whereby the inner cylinder 7 is smoothly slided to the outer cylinder 2 so that the inner cylinder toner discharge openings 9 are smoothly closed. According to the present embodiment as described above, the toner cartrige is so arranged that both the ends of the outer cylinder are provided with notches, the outer cylinder toner discharge openings are provided with a single or a plurality of outer cylinder ribs, and the inner cylinder toner discharge openings are provided with a single or a plurality of inner cylinder ribs, which are located in such a relation that they are not engaged with the outer cylinder ribs each other. This arrangememt makes it possible to avoid such a situation that an outer peripheral surface of the inner cylinder and an inner peripheral surface of the outer cylinder 2 are formed on a sliding face over the whole periphery. Further it is possible to absorb a deformation of the inner cylinder in the outside direction by the outer cylinder toner discharge openings and the notches, and also possible to absorb a deformation of the outer cylinder in the inside direction by the inner cylinder toner discharge openings. Thus, according to the present invention, it is possible to smoothly slide the inner cylinder to the outer cylinder. Further, the toner cartridge according to the present embodiment is so arranged that an edge portion of the inner cylinder toner discharge openings are formed at angles with an edge portion of the outer cylinder toner discharge openings. This arrangememt makes it possible to avoid such a situation that when the inner cylinder toner discharge opening is closed, the edge portions of the inner cylinder toner discharge openings are involved with the edge portions of the outer cylinder toner discharge openings. Thus, according to the present invention, it is possible to smoothly slide the inner cylinder to the outer cylinder.

Claims: A toner cartridge comprising: an outer hollow cylinder (2) having a peripheral surface on which a plurality of outer cylinder toner discharge openings (5), separated by at least one outer cylinder rib (6) extending in the peripheral direction, are formed to extend in a longitudinal direction thereof; and an inner cylinder (7) contained within said outer cylinder (2) in such a relation that it is adjacent to said outer cylinder (2) and rotatably slidable relative thereto, said inner cylinder (7) having a cavity in which a toner may be contained; said inner cylinder (7) having a peripheral surface on which a plurality of inner cylinder toner discharge openings (9), separated by at least one inner cylinder rib (10) extending in the peripheral direction, are formed in a longitudinal direction thereof to communicate with the cavity, said inner cylinder toner discharge openings (9) being to be engaged with said an outer cylinder toner discharge openings (5); CHARACTERIZED IN THAT said at least one outer cylinder rib (6) and said at least one inner cylinder rib (10) are not aligned on the same periphery, so that both cylinders of the cartridge smoothly rotatably slide. A toner cartridge according to claim 1, CHARACTERIZED IN THAT an edge (9a) of said inner cylinder toner discharge openings (9) is formed at an angle with an edge (5a) of said outer cylinder toner discharge openings (5). A toner cartridge according to claim 2, CHARACTERIZED IN THAT said inner cylinder toner discharge openings (9) are generally rectangular. A toner cartridge according to claim 2, CHARACTERIZED IN THAT said outer cylinder toner discharge openings (5) are generally rectangular. A toner cartridge according to any of claims 1-4, CHARACTERIZED IN THAT the opposite ends of said outer cylinder (2) are provided with notches (4).

Inventors: MATSUDA KIYOSHI, MUTOU EISAKU, MATSUDA, KIYOSHI, MUTOU, EISAKU, MATSUDA, KIYOSHI, C/O OKI ELECTRIC IND. CO., LTD., MUTOU, EISAKU, C/O OKI ELECTRIC IND. CO., LTD.
Applicants: OKI ELECTRIC IND CO LTD, OKI ELECTRIC INDUSTRY CO., LTD.
Application year: 1990
Main classification: G03G15
IPC codes: G03G15