JPS60130779A - Separating pawl device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To eliminate the separation of a separating pawl from a photosensitive drum owing to oscillations and prevent the occurrence of transfer paper jamming by supporting the separating pawl pivotally at a specific position with a spring and rotation limiting pin so that it rotates by a specific angle. CONSTITUTION:While the separating pawl 2 is pressed against the photosensitive drum 3, limiting pins 9 are positioned at both side ends of a circular cut groove 8 and the separating pawl 2 is pressed against the photosensitive drum 3 with the force of the spring 6. When a support shaft 1 is rotated counterclockwise, the limiting pins 9 engage one side end of the circumferential cut groove 8 to turn a separating pawl support 4 counterclockwise together with the support shaft 1, thereby separating the separating pawl 2 from the photosensitive drum 3. Further, when the support shaft 1 is moved as shown by an arrow (axially), the separating pawl 2 also moves axially and shifts in contacting position on the circumferential surface of the photosensitive drum 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a separating claw device for separating transfer paper from a photosensitive drum in an electrophotographic copying machine.

In an electrophotographic copying machine, when the separating claw is in contact with the photoreceptor drum, the leading edge of the transfer paper must be guided to the contact position. It is necessary to press the separation claw toward the photoreceptor drum.

As shown in FIG. 1(a), a conventional method is to bring the center of gravity G of the separating claw 2 loosely engaged with the support shaft 1 to the rear and bring it into contact with the photosensitive drum 3 by its own weight. As shown in FIG. 1(b), there is a method in which the separating claw 2 is fixed to the machine frame and brought into contact with the photosensitive drum 3 by elastic force.

However, if pressure is applied at the center of gravity of the separation claw, the vibration of the machine may cause the separation claw to move away from the photoreceptor drum, which may cause a paper jam. , it is necessary to perform many calculations of natural vibrations and experiments, and if the method is fixed to the machine frame and pressurizes the photoreceptor drum, the separation claw always comes into contact with the same position on the photoreceptor drum. As a result, streaks and scratches appear on the photoreceptor drum, appearing as white or black streaks even on a single image, shortening the life of the photoreceptor drum.

The present invention uses a spring to pressurize the photoreceptor drum to prevent it from separating from the photoreceptor drum due to the vibration of the separation claw, thereby preventing the occurrence of a transfer paper jam. to bring them into contact and to separate them,
To provide a separation claw device that can also swing in the axial direction, thereby significantly reducing streaks and scratches on the photoreceptor drum, and thus extending the life of the photoreceptor drum. It is.

Fig. 2 is a perspective view showing an embodiment according to the present invention, in which a separation claw support 4 equipped with separation claws 2 (a case in which three are attached is shown) is mounted on a support shaft 1 which is rotatable and swingable in the axial direction. A spring 6 is provided between the fixing pin 5 provided on the support shaft 1 and the separating claw supporter 4 to bias the separating claw 2 in a direction that presses the separating claw 2 into contact with the facing photoreceptor drum 3. In addition, a groove 8 in the circumferential direction is provided in the supporting shaft reciprocating cylindrical portion 7 of the separation claw support 4, and the groove 8 is located within the groove 8 to limit the range of rotation of the separation claw support 4 by the spring 6. The one-separation claw support 4 is attached to the support shaft 1 by fixing the limiting pin 9 to the support shaft 1.

Therefore, as shown in FIG. 3(a), which is a side sectional view showing the relationship between the separation claw 2 and the photoreceptor drum 3, when the separation claw 2 is in pressure contact with the photoreceptor tram 3, the restriction pin 9 is The separating claw 2 is located between both ends of the circumferential cut groove 8, and is pressed against the photoreceptor drum by the force of the spring 6.
), when the support shaft 1 is rotated counterclockwise,
The restriction pin 9 engages with one side end of the circumferential cut groove 8, rotates the separation claw support 4 counterclockwise together with the support shaft 1, and separates the separation claw 2 from the photosensitive drum 3.

Furthermore, as shown in FIG. 2, when the support shaft 1 is moved in the direction of the arrow (axial direction), the separation claw 2 is also moved in the axial direction with respect to the photoreceptor drum shaft, which causes the photoreceptor drum to move in the opposite direction. However, the contact position can be changed.

Note that the support shaft 1 may be rotated and moved in the axial direction by using appropriate means such as a solenoid.

-Hot Ball As explained above, in the present invention, the separating claw, which is brought into pressure contact with the photoreceptor drum via a spring, is attached to its support shaft so that it can rotate at a fixed angle at a fixed position by means of a spring and a rotation limiting pin. Since the support shaft 1 is rotated, the separation claw 2 can be moved toward and away from the photoreceptor drum 3 at appropriate times.Moreover, if the support shaft 1 is moved in the axial direction, the separation claw 2 can be moved in the axial direction. The contact position to the photosensitive drum 3 can also be changed arbitrarily.

Therefore, according to the present invention, by attaching the separating claw to the support shaft via a spring, the separating claw does not vibrate and can be brought into pressure contact with the photoreceptor drum with a constant force. By moving the support shaft in the direction of the body drum axis, the contact position between the photoconductor drum and separation claw can be changed, which reduces the occurrence of streaks due to abrasion of the photoconductor drum, extending the life of the photoconductor drum. You can also do that.

[Brief explanation of the drawing]

Figure 1 is a side view showing a conventional example, (,) is its own weight, (b)
2 shows a state in which the separating claw and the photoreceptor drum are in pressure contact due to elastic force, FIG. 2 is a perspective view showing the relationship between the separating claw and the support shaft according to the present invention, and FIG. 3 shows the separating claw and the photosensitive drum according to the present invention. FIG. 3 is a cross-sectional view showing the relationship between the two, in which (a) shows a state of contact and (b) shows a state of separation. ■...Support shaft, 2...Separation claw, 3...Photoconductor drum, 4...Separation claw support, 5...Fixing pin, 6
... Spring, 7... Cylindrical part, 8... Cut groove, 9... Rotation limiting pin. Agent Patent Attorney Makoto Kon

Claims (1)

[Claims] A fixing pin provided on a support shaft that pivotally supports the separation claw supporter and a spring passed between the separation claw supporter bias the one separation claw in the direction of pressing against the photoreceptor drum, and also support the separation claw. A circumferential cut groove is provided in the cylindrical portion of the support shaft fitting part of the body, and a limiting pin is fixed to the support shaft, and is located within the cut groove to limit the range of rotation of the separation claw support body by the spring. Separation claw device for electrophotographic copying machine.