JPH0233249Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positioning device for attaching a developing machine to an electrophotographic apparatus.

For maintenance reasons, electrophotographic apparatuses have a structure that makes it easy to take in and out the developing machine.
Therefore, when the developing device is installed, it is necessary to easily position the developing device and to set appropriate conditions.

Conventionally, there were two mechanisms for loading and unloading the developing machine: one for loading and unloading from the operating side, and one for loading and unloading from the top of the device.Among these, the mechanism for loading and unloading from the top is as shown in Figure 1. The developing machine positioning shaft 5 is inserted into the support groove 4 on the main body side, and using this as a fulcrum, the developing machine 2 is pressed from the rear against the photoreceptor 1 side by the pressing member 8.
Abutting the gap retaining ring 7 against the photoreceptor 1,
The developing gap was set to a specified value.

However, there are some twists in the developing machine itself,
A phenomenon may occur in which only one of the gap retaining rings 7 on the operating side and the gap retaining ring 7 on the non-operating side butts against each other, resulting in a problem.

In order to prevent this phenomenon, conventionally, as shown in FIG. 2, a metal plate 9 for adjusting the mounting position of the positioning shaft 5 in the support groove 4 on one side is attached, and the position of the positioning shaft 5 is finely adjusted by sliding the metal plate. Adjustments were made to eliminate uneven contact, but this adjustment was time consuming and troublesome.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, eliminate uneven contact of the developing machine, and enable it to be mounted at a predetermined position without providing a special adjustment mechanism.

This invention focuses on the backlash that occurs when parts are installed, and has a structure that uses the backlash to absorb the uneven contact that occurs due to the twisting of the developing machine itself.
This method has been devised to set a predetermined development gap.

An embodiment of the present invention will be described below with reference to the drawings.

The structure when installing the developing machine will be explained with reference to FIG.

The positioning shaft 5 attached to the developing machine 2 is inserted into the support groove 4 on the apparatus main body 3 side, and the developing machine 2 is rotatable about the positioning shaft 5 as a fulcrum, and a pressing member is pressed against the photoreceptor 1 side. 8 to press the gap retaining ring 7 onto the photoreceptor 1.
to set an appropriate developing gap between the developing roll 6 and the photoreceptor 1.

At this time, as shown in FIG. 3, the support groove 4 for inserting the positioning shaft 5 on the opposite side (opposite side)
Since the play is larger than that on the operating side (front side) shown in FIG. 4, if the operating side gap retaining ring 7 hits the photoreceptor 1 first, the positioning shaft 5 will move in the direction a. However, the gap retaining ring 7 on the non-operating side also comes into contact with the photoreceptor evenly. In addition, if the gap retaining ring on the non-operating side hits the photoconductor first, the positioning shaft 5 moves in the b direction, and the gap retaining ring 7 on the operating side also hits the photoconductor evenly, so that the condition is always normal. Maintain a gap.

In the embodiment of the present invention, it goes without saying that the portion provided with play may be provided on the operation side.

According to the present invention, by providing play between the positioning shaft of the developing machine and the support groove on the main body side,
Since the developing device is not attached unevenly to the photoreceptor, the developing device can be installed without any adjustment.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional example. FIG. 2 is a partial side view showing a conventional positioning shaft adjustment mechanism, and FIGS. 3 and 4 are partial side views showing an embodiment of the present invention. In the figure, 1 is a photoreceptor, 2 is a developing device, 4 is a support groove, 5 is a positioning shaft, 7 is a gap retaining ring, and 9 is a metal plate.

Claims (1)

[Scope of utility model registration request] An electrophotographic apparatus that has a developing roll and a positioning shaft, is rotatably supported on an apparatus main body via the positioning shaft, and rotates about the positioning shaft to bring the developing roll into contact with a photoreceptor. In the developing device, a positioning shaft of the developing device is supported substantially horizontally in a developing device support groove provided in the device main body, and the developing device is mounted on the device main body from the upper direction. A groove having approximately the same size as the outer diameter of the positioning shaft is formed in one of the supporting grooves, and a groove having a size that creates play between the outer diameter of the positioning shaft and the outer diameter of the positioning shaft is formed in the other support groove to prevent the developing device from being connected to the photoreceptor. A developing device characterized by absorbing uneven contact.