Claims
- 1. In an electrostatic copying apparatus comprising a housing; a rotary drum; means mounting said rotary drum rotatably within the housing; said rotary drum including a shaft, bearing members having a circular peripheral surface and mounted on two opposite ends of the shaft, and a drum member fixed to the shaft between the bearing members and having a photosensitive member on at least a part of the peripheral surface thereof; an original-support mechanism disposed on the top surface of the housing and including a transparent plate on which to place an original document to be copied; a charging corona-discharge device for applying corona discharge to the photosensitive member in a latent electrostatic image-forming zone located along the peripheral surface of the rotary drum; and optical unit for projecting the image of an original document placed on the transparent plate onto the photosensitive member in the latent electrostatic image-forming zone; a developing device for developing a latent electrostatic image formed on the photosensitive member by applying toner particles thereto in a developing zone located along the moving path of the photosensitive member and, viewed in the moving direction of the photosensitive member, both downstream of the latent electrostatic image-forming zone and upstream of the transfer zone, said developing device including a frame disposed adjacent the rotary drum and having two side plates spaced from each other a predetermined distance in the direction of the central axis of rotation of the rotary drum and a cylindrical rotary sleeve mounted rotatably between the side plates of the frame and extending substantially parallel to the rotary drum, said sleeve being adapted to hold a developer on its peripheral surface for application to the photosensitive member; and a copying paper transfer unit for transferring a copying paper through a predetermined transfer passage through a transfer zone located along the peripheral surface of the rotary drum and downstream of the developing zone in the rotating direction of the rotary drum; the improvement comprising a pair of guide and support members positioned within the housing and spaced from each other a predetermined distance in the direction of the central axis of rotation of the rotary drum, each of the guide and support members having formed therein a shaft support opening with a recess extending substantially perpendicular to the central axis of rotation of the rotary drum and a main guide surface extending from the lower end of the recess in a direction away from the shaft support opening substantially perpendicularly to the central axis of rotation of the rotary drum such that when each of the peripheral surfaces of the bearing members of the rotary drum is moved along the respective main guide surface, each of the bearing members passes through the respective recess and is positioned within the respective shaft support opening; and a pair of projecting pieces, one projecting piece positioned at each of the two side plates of the frame of the developing device such that after positioning each of the bearing members of the rotary drum in the respective shaft support openings, the free ends of the respective projecting pieces abut the peripheral surfaces of each of the respective bearing members to fix the frame within the housing, the distance between the peripheral surface of the drum member of the rotary drum and the peripheral surface of the sleeve of the developing device being set as required.
- 2. An improved apparatus according to claim 1 wherein the drum member has a non-photosensitive area outside the photosensitive member at both side end portions of the drum member, and each of the guide and support members has formed therein an initial guide surface extending inwardly of the main guide surface and substantially perpendicularly to the central axis of rotation of the rotary drum, so that when each non-photosensitive area of the drum member is moved along the respective initial guide surface, each of the bearing members is positioned on the main guide surface.
- 3. An improved apparatus according to claim 2 wherein the free end of each projecting piece of the two side plates is adapted to abut the peripheral surface of each of the bearings positioned in the shaft support openings and a part of the lower ends of the two side portions of the frame is adapted for placement on the initial guide surface, whereby the frame of the developing device is positioned in place within the housing.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-49497 |
Apr 1980 |
JPX |
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Parent Case Info
This is a division of application Ser. No. 250,829, filed Apr. 3, 1981, now U.S. Pat. No. 4,382,674.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4325626 |
Murata et al. |
Apr 1982 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
250829 |
Apr 1981 |
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