Device for manual replacement of the roller of a copying machine

The invention relates to a device for manual replacement of a roller of a copying machine and more particularly to a device for manual replacement of a copying machine fuser roller.

Copying machines are known in the form of copiers in which a roller is replaceable for service purposes, the roller being equipped with a carrying feature, in which it can turn freely around its center axis. The copying machine has rollers, in a roller pair arrangement, for routing and delivering a toner image-bearing recording medium in the form of a sheet or strip. The rollers are supported at their axial ends and are operated in rotation in an adjoining, axially parallel arrangement in bearing points of the copying machine. There are manually activated mechanisms for releasing the rollers in their bearing points, and for separating the rollers in the radial direction for purposes of removing them from, and inserting them into, their bearing points.

U.S. Pat. No. 4,121,089 discloses a copier machine, in which the fixing unit for toner image-bearing sheets of paper can be removed laterally from the copier for service purposes and has a mechanism in the form of a manually actuated swiveling lever system for release of the fixer/heating roller. The fixing/heating roller moreover has carrying features, for its replacement and carrying. The carrying feature is in the form of a single U-shaped carrying handle which is located rigidly on a U-shaped holding frame spaced in the middle between the axial ends of the fixing/heating roller and radially to the center axis of the roller. The U-shaped holding frame, on its free U-leg ends, has one pivot bearing each for one of the axial shaft ends of the roller in which it can be freely turned. Moreover, the holding frame, on the outside, on its free U-leg ends, has cube-shaped, separate bearing blocks which are connected rigidly to the leg ends. The fixing/heating roller can be inserted/removed into/from the U-shaped bearing points of the fixing unit by the cube-shaped separate bearing blocks. The pressure roller, which is located obliquely underneath the fixing/heating roller, does not have any carrying handles and can only be replaced using a tool.

The deficiency of this disclosed prior art arrangement is that when using large, heavy rollers, for purposes of improving fixing quality, it is difficult to replace and carry the fixing/heating roller by a single central carrying handle without jamming and damaging of the bearing points. Removing a heavy, hot fixing/heating roller and depositing it on a resting surface cannot be done without endangering the service personnel and damaging the roller, since when the roller is laid down it lies directly on the resting surface and can roll away. Furthermore, due to the alignment of the input/output openings of the machine-side U-shaped bearing points, which alignment deviates from the vertical, it is very difficult to insert a large, heavy roller using the central carrying handle, since the roller must be swiveled around the carrying handle to be inserted into the bearing points. Moreover, for purposes of replacing the pressure roller the disclosed embodiment and arrangement of the carrying handle could not be used since the carrying handle would project into an area of the transport path for the toner image-bearing sheets.

Therefore it is an important purpose of the invention to provide a device which overcomes these defects, and which makes it safer and easier to carry out customer service of the copying machine, especially the replacement of heavy and large rollers, and moreover has a simple, compact, economical structure.

The purpose of the invention is achieved with a device wherein rollers have on their two axial ends one carrying handle each, as the carrying mechanism, which handles are located eccentrically to the center axis of the roller. Accordingly the roller hangs down vertically underneath the carrying handles due to its weight in the manual removal from and insertion into the vertically and radially oriented input/output openings of the bearing points of the copying machine. Advantageously, the carrying handles are attached using annular mechanisms to annular pivot bearings which are concentrically located rigidly on the shaft ends of the roller, and the carrying handles of the roller project in the axial direction beyond their bearing points in the machine. Furthermore, the two attachment mechanisms of the carrying handles are axially and radially centered, guiding and holding of the roller in its machine bearing points; and the two attachment mechanisms of the carrying handles aid in depositing the roller which has been removed from the bearing points on the machine on a resting surface.

Advantageously the carrying handles are attached using annular means to annular pivot bearings which are concentrically located rigidly on the shaft ends of the roller, and the carrying handles of the roller project in the axial direction beyond their bearing points in the machine.

Furthermore, the two attachment means of the carrying handles have means for axial and radial centering, guiding and holding of the roller in its machine bearing points; and the two attachment means of the carrying handles have means for depositing the roller which has been removed from the bearing points on the machine on a resting surface.

Moreover the mechanism for centering, guiding and holding the roller are essentially annular disks which are located concentrically around the shaft ends of the roller. The outside diameter of the disks is greater than that of the roller; and the means for depositing the roller are made as a flattened area on the outside periphery of the annular disk of the means on the bottom side opposite the carrying handles, the flattened area with its support surface projecting by a predetermined amount beyond the outside diameter of the roller.

The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiment presented below.

FIG. 1 shows the device according to the invention on the pressure roller of a fixing unit which has been opened and removed from a copying machine, in a three-dimensional representation,

FIG. 2 shows the device from FIG. 1 on a pressure roller which has been released from the fixing unit, in an enlarged three-dimensional view,

FIG. 3 shows the device from FIG. 2 as an enlarged partial representation in a front view, and

FIG. 4 shows the device from FIG. 3 in a side view.

The following description referring to FIGS. 1 to 4 relates to one preferred embodiment of the device according to the invention for manual replacement and deposition of the roller of a copying machine. The device here is located on the pressure roller of a machine or a fixing unit, the fixing unit being located in a copying machine of the conventional type which is not shown. For one skilled in the art in this field it goes without saying that the inventive device can also be used in other machines, such as in printers, image transfer units, photoprinters with fixing units and sheet/strip conveyor units or in sheet sorters with sheet conveyor units and that the rollers can also be made in the form of fixing/heating, image transfer or sheet conveyor rollers.

The device here is located on the pressure roller of a machine or a fixing unit, the fixing unit being located in a copying machine of the conventional type which is not shown, for example, a copier.

For one skilled in the art in this field it goes without saying that the inventive device can also be used in other machines, such as in printers, image transfer units, photoprinters with fixing units and sheet/strip conveyor units or in sheet sorters with sheet conveyor units and that the rollers can also be made in the form of fixing/heating, image transfer or sheet conveyor rollers.

The fixing unit F which is shown in FIG. 1 is shown in the position removed laterally from the copier, on a carriage of the conventional type (which is not shown) and in a closed position. A pressure roller 1 , or first lower roller, and fixing roller 2 , or second upper roller, are pressed radially against one another. The fixing unit F pressure roller 1 in the lower part of the chassis and fixing roller 2 in the upper part of the chassis are in a roller pair arrangement for routing through and conveying a recording medium S in the form of a sheet or strip. The rollers are supported with their axial ends in bearing points L 1 ; L 2 ; L 3 ; L 4 of the chassis parts, to be able to operate by rotation, in the closed position of the fixing unit in an adjoining, axially parallel arrangement.

A manually activated mechanism 3 is provided to swivel the upper chassis part of the fixing unit F or to separate the rollers 1 ; 2 in the radial direction into the open position of the fixing unit and to release/fix them, for purposes of removal of the pressure roller 1 from its bearing points L 1 ; L 2 and/or insertion into them. The manually activated means 3 includes a toggle lever unit with a handle and with an actuating lever 30 . The pressure roller 1 is equipped with carrying mechanisms T 1 ; T 2 , which each have conventional pivot bearings in which the pressure roller is mounted to be able to turn freely around its center axis X 1 . Furthermore, the pressure roller 1 is equipped with a heating lamp H (see FIG. 3) which is attached centered in it for purposes of its heating. The pressure roller 1 , as shown in FIGS. 1 to 4 , has on its two axial ends as the carrying mechanism carrying handles T 1 ; T 2 . Each handle is located eccentrically with respect to the center axis X 1 of the roller 1 , such that the roller hangs down vertically underneath the carrying handles, due to its weight, in manual removal from and insertion into the input/output openings of the bearing points of the machine F, which openings run vertically and radially.

As shown in FIGS. 2 to 4 , the carrying handles T 1 ; T 2 are attached by annular members 10 ; 11 to annular pivot bearings 13 . The pivot bearings 13 , concentrically located rigidly on the two shaft ends 12 of the pressure roller 1 , are for example conventional ball bearings or roller bearings pressed onto the two shaft ends on the outside periphery. The annular members 10 ; 11 are spaced axially to the pressure roller. The attachment annular members 10 ; 11 of the carrying handles T 1 ; T 2 provide respectively for axial and radial centering, guiding and holding of the pressure roller 1 in its machine bearing points L 1 ; L 2 , and for depositing the pressure roller 1 which has been removed from the bearing points L 1 ; L 2 of the machine or the fixing unit F on a conventional resting surface which is not shown.

The annular members 10 for centering, guiding and holding of the pressure roller 1 , as shown in FIGS. 3 and 4, essentially annular disks which are arranged concentrically around the shaft ends 12 of the roller, and which have an outside diameter which is larger than that of the pressure roller 1 . The annular members 11 for depositing the pressure roller 1 are flattened areas on the outside circumference of the annular disks the annular members 10 . On the bottom side of the flattened area, which is opposite the carrying handles T 1 ; T 2 , the flattened area, with its flat support surface, projects by a predetermined amount D beyond the outside diameter of the roller. Accordingly, when the pressure roller 1 is deposited on a resting surface, for example a table top, the pressure roller 1 with its outside circumference does not touch the resting surface and cannot roll away due to the flattened area.

Each annular disk 10 of the two attachments annular members 10 ; 11 has essentially two ring halves 10 . 1 ; 10 . 2 . The ends E of the two ring halves are bent at a right angle for joining the ring halves to one another such that the carrying handles T 1 ; T 2 can be aligned and fixed to the essentially slotted input/output openings of the bearing points L 1 ; L 2 of the fixing unit F. Such openings run from top to bottom radially from the outside circumference to the center axis Y 1 , when the pressure roller 1 is inserted from overhead into the bearing points L 1 ; L 2 of the device F. To do this the bent ends E of the ring halves 10 . 1 ; 10 . 2 fixed on the pivot bearings 13 , which ends are connected among one another by connecting elements 14 (for example screws) rest on radial stops/supports 22 in the bearing points L 1 ; L 2 . As shown in FIG. 2, the two attachment annular members 10 ; 11 of the carrying handles T 1 ; T 2 are held radially and axially centered by the inside peripheral area of their annular disks, or ring halves 10 . 1 ; 10 . 2 , in a groove 15 which runs around the outside periphery of the assigned annular pivot bearing 13 , and are fixed rigidly on the pivot bearings 13 by the screws 14 which are screwed in on the bent ends of the ring halves. Furthermore, for the pressure roller 1 inserted into the fixing unit F, the two attachment annular members 10 ; 11 of the carrying handles T 1 ; T 2 can be held radially and axially centered by the outside peripheral area of their annular disks and the lower ring halves 10 . 2 in a groove 21 . The groove 21 runs around the inside periphery of the assigned semicircular bearing points L 1 ; L 2 , especially the inside periphery of the essentially semicircular or U-shaped bearing clips 20 of the bearing points. The ends E of the lower ring halves 10 . 2 encompass roughly 200 degrees angle at the circumference lying on the stops 22 , and are offset axially to the groove 21 in the direction of the roller.

The carrying handles T 1 ; T 2 of the pressure roller 1 , as shown in FIGS. 1 to 4 , are rigidly attached to the upper area of the upper ring halves 10 . 1 offset radially to the center axis X 1 of the pressure roller by connecting element 17 , for example, two screws. For improved handling of the pressure roller 1 during replacement by an operator and for formation of a free area above the roller the carrying handles, in the form of essentially cylindrical knobs, are arranged such that they project in the axial direction to the outside beyond their bearing points L 1 ; L 2 of the machine or the fixing unit F. To keep the rod-shaped heating lamp H in the center of the hollow pressure roller 1 , and to shield the carrying handles T 1 ; T 2 against the thermal radiation of the heating lamp, on the two axial ends of the pressure roller 1 , one lamp holders 16 is externally connected to each of the upper ring halves 10 . 1 of the carrying handle attachment annular member 10 . Each lamp holder i 6 is in the form of a Z-shaped sheet metal angle. The lamp holders 16 have circular openings with V-shaped, elastic insertion slots for holding or clamping the axial ends of the heating lamp.

The invention has been described in detail with particular reference to certain preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

L 1 first bearing point/s for 1st roller (pressure roller) in the fixing unit

L 2 second bearing point/s for 1st roller (pressure roller) in the fixing unit

L 3 first bearing point/s for 2nd roller (fixing/heating roller) in the fixing unit

L 4 second bearing point/s for 2nd roller (fixing/heating roller) in the fixing unit

D distance between the outside circumference of the 1st roller and the support surface of the lower ring half of the attachment means/annular disks for the carrying handle

E bent ends on the ring halves of the attachment means of the carrying handles

F fixing unit

H heating lamp of 1st roller (pressure roller)

S recording medium/sheet or strip (paper, film, etc.)

T 1 first carrying handle/s of carrying means of the 1st roller

T 2 second carrying handle/s of carrying means of the 1st roller

X 1 center axis of 1st roller

X 2 center axis of 2nd roller

Y 1 center axis of the bearing point for the 1st roller

Y 2 center axis of the bearing point for the 2nd roller

Z swiveling axis of the top and bottom chassis parts of the fixing unit

1 first/bottom roller (pressure roller) of the fixing unit

2 second/top roller (fixing/heating roller) of the fixing unit

3 means for radially separating (pressing together) the rollers in the fixing unit

10 attachment means/annular disk for carrying handle/s on the 1st roller and means for axial/radial centering, guiding, and holding of the 1st roller in the bearing points of the fixing unit

10 . 1 first/top ring half of the attachment means

10 . 2 second/bottom ring half of the attachment means

11 means for depositing the 1st roller (radial flattened area on the second lower ring half of the attachment means/annular disk)

12 shaft end of the 1st roller

13 pivot bearing on the shaft end of the 1st roller

14 connecting element (screw) for the ring half

15 groove on the outside periphery of the pivot bearing for attachment means (ring halves)

16 lamp holder on the attachment means for the carrying handle

17 connecting element (screw) for the carrying handle on the attachment means

20 bearing clip for the 1st roller (pressure roller)

21 groove on the inside periphery of the bearing clip for the attachment means (lower ring half)

22 stop/support for the angled ends of the ring halves on the bearing clip

30 actuating lever of the separating means/swiveling means for the rollers