JPS6014267A - Opening and closing mechanism of gripper for holding transfer material - Google Patents

Abstract

PURPOSE:To eliminate both an uneven rotation due to driving of a gripper and a color shift due to a vibration, and to obtain an image having a good quality by constituting so that opening and closing of the gripper of a transfer material are driven directly by an electromagnetic solenoid. CONSTITUTION:A gripper plate 9 of a gripper 4a is energized clockwise by a spring 21, and the tip of a transfer material is inserted and held between said plate and a transfer drum 4. When a transfer is started, an iron core 20 of a solenoid 19 pushes one end 9a of the gripper plate, the gripper 4a is opened and the transfer material is inserted, subsequently, the iron core 20 moves backward and the gripper 4a is closed, the transfer material in inserted and held, and shifted to a transfer process, and when the transfer is ended, the gripper 4a is opened, and also, a pushing-up rod 14 projects and separates the transfer material from the transfer drum 4. Since the solenoid 19 rotates together with the transfer drum 4, a cam mechanism for opening and closing the gripper becomes unnecessary, an uneven rotation due to said mechanism and a color shift due to a vibration are eliminated, and an image having a good quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an opening/closing mechanism of a gripper of a copying machine or the like that transfers a toner image onto a photographic material.

Conventionally, in this type of gripper opening/closing device, the gripper was opened and closed by a cam sliding and displacing the cam 7 lower attached to the gripper. but,
According to such a configuration, when the gripper is opened and closed, the cam and the lower of the cam 7 collide with each other, causing vibrations in the transfer device and the photoreceptor, resulting in rotational deviation and uneven transfer. Particularly in color copying machines, this has been a cause of color smearing and donor scattering between toner images of each color transferred to a transfer material. Further, the gripper is opened and closed when the transfer material is supplied to the gripper and when the transfer material is discharged after transfer.

For this reason, cam mechanisms for opening and closing the grippers are generally required at both the transfer material supply position and the transfer material discharge position. Conventionally, this has made the transfer device complicated and heavy, which has hindered the miniaturization and weight reduction of the main device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gripper opening/closing mechanism for a transfer bag Wt in a copying machine or the like, which eliminates the drawbacks of the conventional example described above.

One specific embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a main part of an apparatus showing an example of an electrophotographic color copying machine to which the present invention can be applied. In the figure, 1 is a cassette loaded with transfer material, 2 is a feeding roller that feeds a sheet-like member, 3 is a registration roller that adjusts the timing of the transfer material, and 4 is a transfer material holding drum that supports the transfer material. , 5 is a transfer corona discharger that transfers the image formed on the photosensitive drum 7 to a transfer material, 6 is a fixing device that fixes the toner image to the transfer material, and Y-M-C is a yellow, magenta,
This is a developing device for each cyan color.

In the device described above, the transfer material is carried out from the cassette 1 by the feeding roller 2, and the positional timing of the leading edge of the transfer material and the leading edge of the image on the photosensitive drum is determined by the registration roller 6. Then, the transfer material is supplied to a gripper 4a provided on the transfer material holding drum 4 and gripped. After the toner image is transferred for each color to the sheet-like transfer material by the transfer discharge device 5, the transfer material is separated from the drum 4, the toner image is fixed by the fixing device 6, and the toner image is fixed to the tray 1 outside the machine.
is discharged.

The opening and closing structure of the gripper according to the present invention is as shown in FIG. The gripper has a gripper shaft 8, a gripper plate 9 mounted on the gripper shaft, and an abutment member 10 mounted on the underside of the gripper plate 9 with screws.The gripper shaft 8 is attached to the transfer drum body at both ends. Rotatably supported.

Further, in order to hold the gripper plate 9 in a pressed state so that it does not protrude from the transfer drum surface, a coil spring 21 is attached to both ends of the gripper shaft 8, and a hook portion formed at one end of this coil spring is attached to an abutting portion 10. engages in the groove of the
The other end of this coil spring is engaged in a groove (not shown) provided in the transfer drum body, and rotational force is applied to the gripper plate 9 in a direction to always grip the paper surface.

The mounting surface of the above-mentioned gripper mechanism has a flat surface 12 that is lowered one step at a position where the tip of the gripper plate 9 touches, and this surface prevents the gripper plate 9 from rotating. An elastic member 16 for buffering is provided on the plane 12, and a push-up @A14 is attached through a notch in the elastic member 13. As shown in FIGS. 2 and 3, the lower part of the push-up bar 14 is attached inside the guide 15 so as to be movable in the vertical direction.

Next, the opening/closing mechanism of the gripper mechanism will be shown in accordance with FIGS. 2 to 5. When the solenoid 1″9 is energized by applying a current, the movable iron core 20 pushes one end 9a of the gripper plate as shown in FIG. The gripper plate 9a is rotated counterclockwise to open the gripper 4a.When the current to the solenoid 19 is cut off, the gripper plate 9a is automatically closed again by the force of the spring 21 and returns to the position shown in FIG. 14 is always subjected to a force in the direction of popping out by the force of a coil spring 26 (see FIG. 4 (1)) provided inside the guide 15.

On the other hand, a pin 16, which is integrally attached to the push-up bar 14 and projects horizontally from its lower end, passes through a notch 17 in the guide 15 and fits into the push-up member 1B. When this pin 16 is fitted into the locking member 1B shown in FIGS. 4 and 5, the push-up bar 14 is stationary at the position shown by the solid line in FIG. When released, the push-up bar is pushed up by the spring until the pin 16 reaches the upper end of the notch 22, and then comes to rest at the position shown by the broken line in FIG. The locking member 18 is rotatable with respect to the guide 15 by a shaft 26, and is attached with some leeway in the axial direction. The coil spring 24 is engaged by a shaft 23 with a stopper 25, a support portion 18a which is a part of the lock member 1B folded back, and a shaft 23.
8 is applied with a counterclockwise rotational force, and this locking member is pressed against the guide 15.

When the transfer material is to be supplied to the gripper 4a, the toroid 19 is energized and the gripper plate 9 is opened as shown in FIG. As a result, the push-up bar 14 tends to protrude beyond the peripheral surface of the transfer drum due to the spring 26. However, when the gripper plate 9 is about to open, the locking member 1B is in the fifth position, which is the state where the transfer material is separated from the drum surface.
From the state shown in FIG. 1, the gripper plate 9 is closed again and the push-up rod 14 is pushed down to the position shown in FIG. 5 (2).

When the gripper plate 9 is released from above the push-up bar 14 in the state shown in FIG. However, at this time, the lock member 18 is urged by the coil spring 24 to rotate counterclockwise about the shaft 23. Therefore, as the pin 16 moves upward, the locking member 18 engages with the pin 16 at the position shown in FIG. 5(3), and therefore the push-up bar 14 stops at the position shown in FIG. 5(3). do. At this time, the amount of lift of the push-up bar 14 is determined by the amount by which the gripper 4 of the transfer material
The height is maintained at a level that does not obstruct access to a. After the transfer material is supplied, the current to the solenoid 19 is cut off, and the gripper plate 9 is closed by the force of the coil spring 21, gripping the transfer material and simultaneously pushing down the push-up bar 14. As a result, the pin 14 moves downward, and at the same time, the locking member 1B rotates and enters under the protrusion 18a, and the pin 16 reaches the point shown in FIG. 5(4).

The protrusion 1Sa is bent outward as shown in FIG. 4(2). Therefore, when all the transfer steps on the transfer material are completed, the solenoid 19 is energized to eject the paper, the gripper plate 9 opens, and the push-up bar 14 attempts to rise due to the spring. Then, the pin 16 pushes the locking member 18 toward the front side in FIG. 5 along the inside of the claw-shaped protrusion 18&, and
The pin is released from this locking member. As a result, the pin 16 of the push-up bar 14 is inserted into the notch 2, as shown in FIG. 5(1).
2 and stops at the position indicated by the broken line in FIG. At this time, in this state, the push-up bar 14 holds the leading edge of the transfer material that has completed all the pine forest processes, and lifts the leading edge of the transfer material onto a separation claw (not shown) facing the transfer drum. By raising the transfer material, the transfer material is assisted in being separated by the transfer drum.

After the paper is ejected, the gripper plate 9 closes by stopping the power supply to the threaded board, and when the push-up bar 14 is pushed down, the pin 16
is the oblique side 1 of the locking member 18 against the force of the coil spring 24.
By pressing 8b, it is rotated clockwise and lowered while being pushed away, returning to the point shown in FIG. 5 (2), in preparation for the next transfer.

When such an opening/closing mechanism for the gripper 4 is disposed near the inner circumferential surface of the transfer drum, the transfer discharger disposed inside the transfer drum is moved between the operating position and the retracted position in preparation for the passage of the solenoid 19, guide member, etc. It moves between positions using the driving force of a cam or trail. Since these dischargers and the means for moving the dischargers are attached to a fixed part of the transfer unit, the influence of vibrations and the like caused by the movement of the dischargers on the transfer drum can be suppressed to a sufficiently small level.

As explained above, in the gripper opening/closing device according to the present invention, the solenoid 19 that opens and closes the gripper rotates together with the transfer drum, so that the moving transfer drum does not collide with the stationary cam as in the conventional example. Therefore, there is no impact due to collision. Therefore, it is possible to prevent color shift and toner scattering due to vibrations and uneven rotation caused by the opening and closing operations of the gripper, and furthermore, it is possible to prevent the copy image from being disturbed as a result. In addition, separation of the transfer material can be reliably performed by using a push-up bar.

Note that the gripper opening/closing mechanism of the present invention is applicable not only to color copying machines but also to monochrome copying machines or recording apparatuses that include a toner image transfer process. Further, the image carrier is not limited to the electrophotographic photoreceptor of the embodiment, but may also be an insulated drum.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of a color copying machine to which the present invention can be applied, and FIGS. 2 and 3 show a push-up bar 1 of the gripper of the present invention.
FIG. 4 is an explanatory diagram showing a fourth driving mode. In the figure, 4 is a transfer drum, 4a is a gripper section, 9 is a gripper plate, 19 is a solenoid, S20 is a movable iron core, 2
1 indicates a spring. Japanese Patent Application Sho GO-14267 (4)

Claims (1)

[Claims] (1) An opening/closing mechanism for a gripper that grips a transfer material, which is characterized by directly driving the transfer material that grips the leading edge of the sheet-like transfer material and transfers a toner image on an image carrier while moving endlessly.