Coupling arrangement

Abstract

 In a coupling arrangement (10) which comprises a first coupling part (1) for driving a printer drum and which comprises a second coupling part (2) for driving a developer drum, with the first coupling part (1) and the second coupling part (2) being movable in a predeterminable way between a decoupling position (20) and a coupling position (30), it is proposed that the first coupling part (1) and the second coupling part (2) are coupled with at least one coupling means (3), and that the at least one coupling means (3) is arranged in such a way that the displacement of merely the first coupling part (1) from the decoupling position (20) to the coupling position (30) is excluded.

Description

[0001] The invention relates to a coupling arrangement according to the preamble of claim 1.

[0002] The coupling arrangement is used for coupling at least one drive unit of a printing unit with the printer drum and the developer drum of a cassette, especially toner cassette. Printer drum and developer drum are enclosed by the cassette, which cassette is arranged to be inserted into the printer unit and removed from the printer unit. The drive unit and the cassette must be separated from each other for inserting the cassette, especially a full toner cassette, into the printer unit and for removing the cassette, especially an empty toner cassette, from the printer unit. Such printer units can be arranged as a fax machine, multifunctional machine, a copying machine, home office printer and/or as an industrial printer.

[0003] The fault is known in conventional coupling arrangements that driving is merely made with the printer drum. Although the paper is conveyed without fault through the printer unit, no toner is transferred to the receiving medium, which is especially a sheet of paper. The disadvantageous aspect is that this fault is not recognized by the printer unit, but the receiving medium is not printed, through which the printed information is lost.

[0004] It is the object of the invention to provide a coupling arrangement of the kind mentioned above with which it can reliably be prevented that the printing information is lost during the printing of a receiving medium to be printed.

[0005] This is achieved by the features of claim 1.

[0006] The coupling means causes an advantageous cooperation of first coupling part and second coupling part, with the coupling means ensuring that a displacement of merely the first coupling part from its decoupling position to the coupling position is prevented.

[0007] The sub-claims, which simultaneously form a part of the description like claim 1, relate to further advantageous embodiments of the invention.

[0008] It can be provided especially in this connection that the coupling means is arranged as a driver plate which connects the second coupling part with the first coupling part in such a way that merely motions of the second coupling part from the coupling position to the decoupling position can be transferred to the first coupling part. As a result, the first coupling part and the second coupling part can be coupled and decoupled and the coupling means can be arranged in an especially simple way. It is further advantageous in this respect that the printing unit need not monitor the relative positions of the first coupling part, the second coupling part and the coupling means.

[0009] The invention is now described in closer detail by reference to the enclosed drawings which merely show preferred embodiments in an exemplary way, wherein:

Fig. 1 shows the coupling arrangement of an especially preferred first embodiment in a first oblique view and a part of the toner cassette, with the first coupling part and the second coupling part being arranged in the decoupling position;

Fig. 2 shows the coupling arrangement of Fig. 1 in a second oblique view, with the first coupling part and the second coupling part being arranged in the coupling position, and

Fig. 3 shows the coupling arrangement of Fig. 1 in a third oblique view, with the first coupling part being arranged in the decoupling position and the second coupling part in the coupling position.

[0010] Figs. 1 to 3 show a coupling arrangement 10 which comprises a first coupling part 1 for driving a printer drum and a second coupling part 2 for driving a developer drum, with the first coupling part 1 and the second coupling part 2 being movable in a predeterminable manner between a decoupling position 20 and a coupling position 30. It is proposed in this coupling arrangement 10, in order to prevent losing the printing information during the printing of a receiving medium, that the first coupling part 1 and the second coupling part 2 are coupled with at least one coupling means 3, and that at least one coupling means 3 is arranged in such a way that a displacement of merely the first coupling part 1 form the decoupling position 20 to the coupling position 30 is excluded.

[0011] The exclusion of displacing merely the first coupling part 1 from the coupling position 20 to the coupling position 30 is ensured in such a way that when the second coupling part 2 is arranged in its decoupling position 20, the coupling means 3 is also arranged in its decoupling position 20, as is shown in Fig. 1, and that as a result of the arrangement of the coupling means 3 in its decoupling position 20 the first coupling part 1 is inevitably also arranged in its decoupling position 20.

[0012] It is ensured by means of the coupling means 3 that a displacement of merely the first coupling part 1 from its decoupling position 20 to the coupling position is prevented.

[0013] The printer drum and the developer drum are enclosed by a cassette, especially a toner cassette, which cassette is provided for changing. For changing the cassette, it is inserted in a printing unit and/or removed from the printing unit. The printing unit comprises the driving unit.

[0014] The coupling arrangement 10 is provided for arrangement in a printer, with the coupling arrangement 10 being enclosed by the printing unit in which the cassette, and especially a toner cassette, can be inserted.

[0015] The printing unit can be arranged as a fax machine, copying machine, computer printer, as a so-called multifunctional device for scanning, faxing and printing or the like, with the printing unit comprising the coupling arrangement in accordance with the invention.

[0016] Fig. 1 shows the first coupling part 1, the second coupling part 2 and the coupling means 2, each in their decoupling position 20. The printer drum, developer drum, and the cassette in particular, are separated from the drive unit of the printing unit, so that the cassette can be displaced relative to the printing unit, especially a housing of the printing unit.

[0017] Fig. 2 shows the first coupling part 1, the second coupling part 2 and the coupling means 3 in their respective coupling position 30. In this position, the printing unit and the cassette inserted into the printing unit are in operating readiness, with the printer drum causing the conveyance of the receiving medium, especially the sheet of paper, during the printing of the receiving medium by means of the printing unit and the developer drum causing the application of toner on the receiving medium. The error-free printing of the receiving medium for receiving the printing information can thus be ensured reliably.

[0018] Fig. 3 shows the first coupling part 1 in its decoupling position 20 and the second coupling part 2 as well as the coupling means 3 in their coupling position 30. There cannot be any conveyance of the medium to be printed here, so that the printing unit will report back a paper jam as an error message when attempts are made to print the receiving medium. It is advantageous that thus the output of a substantially empty receiving medium can be prevented, thus preventing that printing information is lost.

[0019] As shown in Figs. 1 to 3, it can especially be provided that the first coupling part 1 is arranged as a first drive shaft with a first rotational axis 11 and is arranged in a longitudinally displaceable manner from the decoupling position 20 to the coupling position 30 in the direction of the first rotational axis 11. This enables an especially simple and especially energy-saving displacement of the first coupling part 1.

[0020] As also shown in Figs. 1 to 3, it can especially be provided that the second coupling part 2 is arranged as a second drive shaft with a second rotational axis 21 and is arranged in a longitudinally displaceable manner from the decoupling position 20 to the coupling position 30 in the direction of the second rotational axis 21. This enables an especially simple and especially energy-saving displacement of the second coupling part 2.

[0021] The first coupling part 1 and/or the second coupling part 2 can be arranged as a pin or as a bushing and can especially engage in a region of the printer drum or developer drum which is arranged in a positive-locking and diametrically opposed way.

[0022] As shown, it can especially be provided that the first coupling part 1 and the second coupling part 2 each comprise an engagement pin 4 which is arranged as a positive-locking connection element. It can especially be provided in this connection that the first coupling part 1 and the second coupling part 2 each have a sleeve 41 and that the respectively one engagement pin 4 is relatively displaceable in the respectively one sleeve. This relative displacement can be directed especially in the direction of the first rotational axis 11 or in the direction of the second rotational axis 21.

[0023] In the preferred first embodiment, the sleeve 41 of the first coupling part 1 is controlled in respect of position for moving the first coupling part 1 to the coupling position 30, with the engagement pin 4 of the first part 1 being simultaneously moved with the sleeve 41. If the engagement pin 4 of the first coupling part 1 meets an obstruction however and cannot couple with the printer drum, the sleeve 41 can be further displacement in the case of an engagement pin 4 which is stationary relative to the housing of the printing unit, with the sleeve 41 being displaced relative to the engagement pin 4. The same can especially also be provided for the sleeve 41 and the engagement pin 4 of the first coupling part 1.
For entrainment of the engagement pin 4 by the sleeve 41 with simultaneous formation of the relative displaceability between engagement pin 4 and the sleeve 41, it can be provided especially that the engagement pin 4 and the sleeve 41 are connected with each other elastically, especially by means of a spring element.

[0024] It can especially be provided that the first coupling part 1 and the second coupling part 2 are each pressurized by a spring 5 in the direction of the coupling position 30. Spring 5 pretensions the coupling parts 1, 2 in the direction of the cassette, i.e. in the direction of the printer drum or developer drum. The displacement to the coupling position 30 can thus occur in an especially simple and reliable way.

[0025] The coupling and decoupling can occur in an especially user-friendly way when it is provided that the second coupling part 2 comprises a disk cam 22 which is provided for controlling the movement between decoupling position 20 and the coupling position 30 by a control element. The control element can be arranged especially by a component of the printing unit, especially a housing part of the printing unit which is arranged so as to make contact with the disk cam 22. The control element can be in connection with a flap of the housing in an especially preferred way, so that the control element is moved relative to the disk cam 22 during the movement of the housing flap of the printing unit, with the control of the movement between the decoupling position 20 and the coupling position 30 occurring in an especially simple and, without any action on the part of the operator, user-friendly way by means of said relative movement. It can especially be provided that the control element is arranged as a part of the housing flap, through which the control element is connected with the housing flap in a firmly positioned way. The housing flap for the cassette can also be designated in this connection as a housing cover for the cassette because it covers the cassette, and especially the toner cassette, from the outside. When the housing flap is opened, access to the cassette inserted in the printing unit is possible.

[0026] It can be provided in an especially preferred way that the coupling means 3 is arranged as a driver disk 31 which connects the second coupling part 2 with the first coupling part 1 in such a way that merely movements of the second coupling part 2 can be transferred from the coupling position 30 to the decoupling position 20 to the first coupling part 1. As a result, the coupling means 3 can be arranged in an especially simple and cost-effective way. It is thus further ensured that a displacement merely of the first coupling part 1 from its decoupling position 20 to the coupling position 30 is prevented.

[0027] In a preferred arrangement of the driver disk 31 it is provided that the driver disk 31 is connected with the second part 2 in a manner as to be fixed against longitudinal displacement, that the first coupling part 1 comprises a stop element 12, and that the driver disk 31 is arranged for contacting a first side of the stop element 12 facing the coupling position 30, as shown in Figs. 1 to 3.

[0028] In this connection it can be provided especially that the driver disk 31 comprises a pass-through opening 32 through which the first coupling part 1 extends, and that the first side rests on the driver disk 31 in the decoupling position 20 of the first coupling part 1. The pass-through opening 32 is covered in Figs. 1 and 2 by the stop element 12 because the driver disk 31 rests in these illustrations on the stop element 12 and is visibly shown in Fig. 3.

[0029] In a further development of the pass-through 32 it can also be arranged with an open edge. The driver disk 31 can be arranged in the area of the pass-through opening 32 in a fork-like manner.

[0030] Further embodiments in accordance with the invention merely have a part of the described features, with any combination of features being provided, especially also of different described embodiments.

Claims

1. Coupling arrangement (10) which comprises a first coupling part (1) for driving a printer drum and which comprises a second coupling part (2) for driving a developer drum, with the first coupling part (1) and the second coupling part (2) being movable in a predeterminable way between a decoupling position (20) and a coupling position (30), characterized in that the first coupling part (1) and the second coupling part (2) are coupled with at least one coupling means (3), and that the at least one coupling means (3) is arranged in such a way that the displacement of merely the first coupling part (1) from the decoupling position (20) to the coupling position (30) is excluded.

2. Coupling arrangement according to claim 1, characterized in that the first coupling part (1) is arranged as a first drive shaft with a first rotational axis (11) and is arranged in a longitudinally displaceable manner from the decoupling position (20) to the coupling position (30) in the direction of the first rotational axis (11).

3. Coupling arrangement according to claim 1 or 2, characterized in that the second coupling part (2) is arranged as a second drive shaft with a second rotational axis (21) and is arranged in a longitudinally displaceable manner from the decoupling position (20) to the coupling position (30) in the direction of the second rotational axis (21).

4. Coupling arrangement according to one of the claims 1 to 3, characterized in that the first coupling part (1) and the second coupling part (2) each comprise an engagement pin (4) which is arranged as a positive-locking connecting element.

5. Coupling arrangement according to one of the claims 1 to 4, characterized in that the first coupling part (1) and the second coupling part (2) are each pressurized by a spring (5) in the direction of the coupling position (30).

6. Coupling arrangement according to one of the claims 1 to 5, characterized in that the second coupling part (2) comprises a disk cam (22) which is provided for controlling the movement between the decoupling position (20) and the coupling position (30) by a control element.

7. Coupling arrangement according to one of the claims 1 to 6, characterized in that the coupling means (3) is arranged as a driver plate (31) which connects the second coupling part (2) with the first coupling part (1) in such a way that merely movements of the second coupling part (2) can be transferred from the coupling position (30) to the decoupling position (20) to the first coupling part (1).

8. Coupling arrangement according to claim 7, characterized in that the driver plate (31) is connected in a longitudinally displaceable way with the second coupling part (2), that the first coupling part (1) comprises a stop element (12) and that the driver plate (31) is arranged for contacting a first side of the stop element (12) facing the coupling position (30).

9. Coupling arrangement according to claim 8, characterized in that the driver plate (31) comprises a pass-through opening (32) through which the first coupling part (1) extends and that the first side rests on the driver plate (31) in the decoupling position (20) of the first coupling part (1).

10. Printing unit with a coupling arrangement (10) according to one of the claims 1 to 9.

Drawing