DE2953472C2 - DEVICE FOR INTERCHANGEABLE STORAGE OF A LIGHT-SENSITIVE RECORDING DRUM IN AN ELECTROPHOTOGRAPHIC COPIER - Google Patents

Description

characterized,

(372) is transferable.

5. Device according to one of claims 1 to 4, characterized in that the shaft (326) and the the hub (322) adjacent to the other bearing (308) each has a conical section (342, 332) exhibit.

6. Device according to one of claims 1 to 5, characterized in that the Sehert walls (292, 294) with the drum (26) and the shaft {£ 26} form an insertable and removable unit (290) in the copier.

25th

- That the shaft (326) as a stub shaft with a conical end section (338) is formed at its insertion end,

- That the inner diameter of one bearing (306) is greater than that of the other bearing (308), corresponding collar sections (548 and 340) being provided on the shaft (326) are,

- That the coupling (364) and the photosensitive drum (26) are on opposite sides of the other bearing (308) are arranged, and

- That the hubs (320,322) of the photosensitive Drum (26) when inserting the drum (26) in the U-shaped holding members (310,312) to the Put on the holding surfaces of the holding members (310,312) and lightly when inserting the shaft (326) be raised.

45

2. Apparatus according to claim 1, characterized in that one of the hubs is on the inner surface (320, 322) of the photosensitive drum (26) an internal thread (330) is formed with a of the shaft (326) located external thread (346) can be brought into engagement, the threads of this Threads (330, 346) run in such a way that they are mutually tightened during rotation when copying.

3. Apparatus according to claim 1 or 2, characterized in that the clutch is a one-way clutch (364) with a plurality of balls (372) arranged in the circumferential direction (arrow 368).

4. Apparatus according to claim 3, characterized in that an input end element (366) of the One-way clutch (3W) with a plurality of Extensions is provided, each having surfaces (370), which in a the shaft (326) according to radially outward to the direction of rotation (368) leaving the direction obliquely, wherein the rotary drive force from the input end element (366) on the shaft (326) over the balls engaging between the recesses and the outer circumference of the shaft (326) The invention relates to a device for exchangeable storage of a photosensitive recording drum in an electrophotographic one Copier in which two bearings for the drum shaft have a common axis and close to the side walls both sides of the drum are arranged in the axial direction, one on the bearing axis Horizontal coupling for transferring the drive force to the shaft after the shaft has been inserted into the coupling is arranged, in which the photosensitive drum in the axial direction has externally arranged hubs, at the holding members on the opposite throat of the side walls, each with an upwardly open or upwardly sloping retaining surface are rigidly attached, and in which the light-sensitive The drum and the shaft can be fixed together as a unit.

From US-PS 30 78 770 such a xerographic display device is known, with the one Microfilm should be able to produce copies automatically, economically and precisely. This device has a Recording drum from a cylinder, which is mounted on both sides on bearings and on one Driving force can be transmitted via a clutch. A replaceable bearing for this recording drum is not provided, as this can only be exchanged after practically all of them Storage is dismantled into individual parts.

Furthermore, the US-PS 39 98 548 describes a recording drum, which on both sides with Receiving members and is provided with side walls. This recording drum is said to be especially without There is a risk of damage to their surface. An interchangeable storage of the Recording drum is not provided here either.

From US-PS 38 40 100 a one-way clutch is also known which is particularly suitable for an electrophotographic printing machine. The at This printing machine's existing drum is also not interchangeable, since first numerous other parts must be removed before access to the drum is even possible.

The US-PS 39 94 053 finally describes a drum bearing for a playback machine in which the Drum is firmly connected to the shaft. The drum itself is not in this drum bearing either exchangeably stored.

Furthermore, from US-PS 41 20 576 a drum bearing is known in which a drum with a shaft is connected, which is attached to a frame in a cantilevered manner. The US-PS 41 14 998 describes finally a copier where the drum is off

removed from the housing to facilitate maintenance can be.

If the photosensitive drum is used for long periods of time, there is a risk that the decrease in electrical properties of the photosensitive layer located on the drum or many small scratches or flaws occur in the layer. Therefore it is necessary to put the drum in to be exchanged at certain intervals. Various devices have been discussed so far to achieve the mount the photosensitive drum in the copier body without touching the photosensitive layer; However, there are problems in terms of the time required during assembly, the necessity the use of tools, e.g. a screwdriver or the like, or possible damage the layer through unwanted contact between the drum and the copier housing.

The invention has set itself the task of providing a device of the type mentioned at the beginning to improve that the recording drum by simple handling z. B. snow during maintenance! and can be safely removed from the housing of the copier.

The features characterized in the main claim serve to solve this problem. The subclaims mark appropriate further training.

The inventive design of the device allows the drum in a simple manner and quickly can be safely removed from the housing of the copier.

The one-way clutch has the following advantages in particular: When one has the driving force to act driving shaft does not rotate, the balls are in the direction of the diameter of this drive shaft biased. At the same time, there is a gap between the balls and the part of the shaft with small Diameter. Because of this gap, the shaft can easily be inserted into or removed from the photosensitive drum. be removed from this. In addition, the driving force from the input end element is via the Balls easily transferred to the small diameter part of the shaft.

In the drawings, an embodiment of the Device according to the invention shown. It shows

F i g. 1 is a perspective view of the holder extended toward the front of the copier body;

F i g. 2 shows a cross-sectional view XII-XII according to FIG. 1;

3 shows a partial cross-section through part of a One way clutch on a larger scale;

4 shows a simplified perspective view of the holder and its surroundings.

As from F i ς. 1 can be seen, the drum 26 and the development unit 32 of the copier and other units detachably on a bracket 290 fixed forward and backward with respect to the copier body 2 (i.e. in one to the paper surface perpendicular direction) is movable back and forth. 1 shows in perspective view the extended bracket 290 comprising front and rear side walls 292 and 294- which are parallel are arranged at a predetermined distance from one another, and can be moved on a rail 300 is led. A handle 302 is attached to the side wall 292 of the bracket 290.

According to Fig. 2 walls 292 and 294 are on the sides Bearings 306 and 308 are attached to a common axle. On the surfaces facing each other U-shaped holding members 310 and 312 are attached to the side walls 292 and 294 and are open to the inside are. On opposite sides of a cylindrical part 22 of the drum 26 are provided with an anchor bolt 318 end plates 314 and 316 attached. End plates 314 and 316 have hub portions 320 and 322 with a common axis extending from part 22 in the direction of this axis to the outside. By doing Space between the hub parts 320 and 322, a guide tube 324 is coaxially defined

κ »F i g. 4 shows the holder 290 in the state in which the drum 26 is inserted from above into the U-shaped holding surfaces of the holding members 310 and 312, the hub parts 320 and 322 contacting lower sections 31la and 312a and the axis of the drum 26 slightly below The configuration of the hub parts 320 and 322 and the positions of the lower portions 310a and 312a of the support members 310 and 312 upwards, downwards and horizontally are dimensioned to be suitable for the arrangement indicated. A shaft 326, which holds the drum 26 in bearings 306 and 3OS, runs successively through the bearing 306, the hub part 320, the guide tube 324, the hub part 322 and the bearing 308 and is connected to a drive unit 323 arranged in the housing 2. The inner circumferential surface of the hub part 320 on the insertion side (right or front side in FIG. 2) has an internal thread 330, while a conical surface on the hub part 322 on the inwardly directed side

ίο 332 adjacent storage area 336 are provided.

The shaft 326 has a tip 338, a portion 340 of reduced diameter, a conical one Part 342, a large diameter section 344, an externally threaded portion 346, another large diameter portion 348, and a head 350 along its axis. The tip 338 is conically shaped towards the free end. The externally threaded section 346 is threadedly connected to the internal thread 330.

The drive unit 328 (Fig. 2) includes a cylindrical support member 354. which is attached to the side wall 236 of the Attached to the housing 2 is a drive shaft 360 and inserted into the holding member 354 via bearings 356 and 358 a gear wheel 100 arranged on the shaft 360. The drive shaft 360 has a gearwheel towards the insertion side of the shaft 326 to open hole 362. In the hole 362, the tip 338 and the section 340 with a small Diameter of the shaft 326 inserted via a one-way clutch 364. The holding member 354, the drive shaft 360, gear 100 and hole 362 share a common axis. The gear 100 is with an im Housing 2 arranged motor connected by a chain.

Part of the one-way clutch 364 is shown enlarged in Pi 2-3. An input end member 366 is attached to the drive shaft 360. This has a plurality of recesses which are formed radially at a distance from one another in the circumferential direction and each have surfaces 370 which in one of the

6G shaft extending radially outward to the direction of rotation 368, between each inclined surface 370 and the A ball 372 is disposed on the circumferential surface of the small diameter portion 340 of the shaft 326. Furthermore, springs 374 are provided, which act on the balls 372 along the rear side of the direction of rotation 368.

As drive shaft 360 and input end member 366 rotate in drive direction 368, each occurs

Ball 372 between the inclined surface 370 and the peripheral surface of the shaft section 340 along the inclined surface 370, as a result of the force of the springs 372 (see. Fig.3a). As a result, the Driving torque from input end member 366 on small diameter portion 340 through the Balls 372 are transferred, and the shaft 326 is integrated with the drive shaft 360 as a unit driven. The rotating movement of the shaft 326 rotates the drum 26. When the drive shaft 360 and, as a result, the input end element 366 are stationary (see FIG. 3), the balls 372 do not kick between the inclined surfaces 370 and the peripheral surface of the shaft 326.

To secure the drum 26 in the copier housing 2, the holder 290 is removed from the housing 2 pulled out. Then the hub parts 320 and 322 of the drum 26 are first turned into the U-shaped Holding sides of the holding members 310 and 312 used, the hub parts 320 and 322 on the bottom parts 310a and 312a of the holding members 310 and 312 are supported. Then the shaft 326 of the Front one after the other through the bearing 306, the hub part 320, the guide tube 324 and the hub part 322 pushed. The tip 338 of the shaft 326 is extending from the guide tube 324 through the Conical surface 332 of the hub part 322 introduced into the bearing surface 336 of the hub part 322.

In the next step, the internal thread 330 of the hub part 320 joins the external thread portion 346 of FIG Shaft 326 engaged by rotating head 350.

and the shaft is screwed to the projecting side (left side in Fig. 2) so that the tip 338 of the Shaft 326 is displaceable through the bearing 308 to the one-way clutch 364. Since the conical section 342 is formed adjacent to the small diameter portion 340 of the shaft 326, further becomes the Large diameter portion 344 inserted into bearing 308 as shaft 326 continues to advance. on this is how tip 338 and section 340 stand

ίο with a small diameter outwards in the axial direction from camp 308. and the drum 26 is thus mounted on the bracket 290.

The bracket 290 is then attached to it mounted drum 26 is pushed into the housing 2.

and thus becomes the small diameter portion 350 of shaft 326 that consists of bearing 308 protrudes outward, into the one-way clutch 364, which is disposed in the hole 362 of the drive shaft 360, inserted. Since the tip 33 »of the white 326 is conical, is the portion 340 of the shaft 326 easily in the One-way coupling 364 can be used.

The threads 330 and 346 run like this. that mutual attraction during copying in Direction of arrow 368 takes place. So even if the Drum 26 with loosened threads 330 and 346 is assembled, the drum 26 and the shaft 326 form one unit during copying. Where / u note that this arrangement can be changed so that. if the hub part 332 has an internal thread it is provided that an external thread which can be brought into engagement therewith is provided on a shaft 326.

For this purpose 4 sheets of drawings

Claims (1)

Patent claims: 1. Device for exchangeable storage of a photosensitive recording drum in one electrophotographic copier, - with the two bearings for the drum shaft have a common axis and on side walls are arranged on both sides of the drum in the axial direction thereof, to - With a coupling lying on the bearing axis to transmit the driving force is arranged on the shaft after the shaft has been inserted into the coupling, - in which the photosensitive drum has hubs arranged on the outside in the axial direction. - in the case of the opposite faces of the Side walls holding members each with an upwardly open or upwardly inclined trending !! Holding surface are rigidly attached, - and in which the photosensitive drum and the shaft can be fixed as a unit with one another are.