Cylindrical structure, process cartridge, and image forming apparatus

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising:

• a frame;
• a photosensitive drum including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and an outer surface coated with a photosensitive material, and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous gear fastened to said at least one open end of said cylinder, said gear having a head fitted into said at least one open end and having a plurality of discrete recesses formed circumferentially around a periphery of said gear, wherein said gear is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said gear in both axial and rotational directions;
• and
• process means for acting on said photosensitive drum.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising:

• a frame;
• an image-bearing member;
• and
• a developing sleeve for supplying a developer to said image-bearing member, said developing sleeve including a metallic cylinder having a wall thickness of 0.3-1.5 mm. having at least one open end and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous flange fastened to said at least one open end of said cylinder, said flange having a head fitted into said at least one open end and having a plurality of discrete recesses formed circumferentially around a periphery of said flange, wherein said flange is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder, at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said flange in both axial and rotational directions.

An electrophotographic image forming apparatus for forming images on a recording medium, said image forming apparatus comprising:

• a process cartridge detachably mountable to said image forming apparatus, said process cartridge including a frame;
• a photosensitive drum including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and an outer surface coated with a photosensitive material, and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous gear fastened to said at least one open end of said cylinder, said gear having a head fitted into said at least one open end and having a plurality of discrete recesses formed circumferentially around a periphery of said gear, wherein said gear is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder, at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said gear in both axial and rotational directions;
• and process means for acting on said photosensitive drum;
• means for mounting said process cartridge;
• and
• means for conveying the recording medium.

An electrophotographic image forming apparatus for forming images on a recording medium, said image forming apparatus comprising:

• a process cartridge detachably mountable to said image forming apparatus, said process cartridge including a frame;
• an image-bearing member;
• and a developing sleeve for supplying a developer to said image-bearing member, said developing sleeve including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and having an inner surface, disposed at a portion adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous flange fastened to said at least one open end of said cylinder, said flange having a head fitted into said at least one open end and having a plurality of discrete recesses formed circumferentially around a periphery of said flange, wherein said flange is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder, at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said flange in both axial and rotational directions;
• means for mounting said process cartridge;
• and
• means for conveying the recording medium.

An electrophotographic image forming apparatus for forming an image on a recording medium, said image forming apparatus comprising:

• a photosensitive drum including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and an outer surface coated with a photosensitive material, and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous gear fastened to said at least one open end of said cylinder, said gear having a head fitted into said at least one open end and having a plurality of discrete recesses formed circumferentially around a periphery of said gear, wherein said gear is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder, at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said gear in both axial and rotational directions;
• process means for acting on said photosensitive drum;
• means for transferring an image formed on said photosensitive drum to the recording medium;
• and
• means for conveying the recording medium.

An electrophotographic image forming apparatus for forming an image on a recording medium, said image forming apparatus comprising:

• an image-bearing member;
• a developing sleeve for supplying a developer to said image-bearing member, said developing sleeve including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous flange fastened to said at least one open end of said cylinder, said flange having a head fitted into said at least one open end and having a plurality of discrete recesses, formed circumferentially around a periphery of said flange, wherein said flange is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder, at positions spaced circumferentially around said at least one open end such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said flange in both axial and rotational directions;
• means for transferring an image formed on said image bearing member to the recording medium;
• and
• means for conveying the recording medium.

A developing sleeve for use in an electrophotographic image forming apparatus, said developing sleeve comprising:

• a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end and having an inner surface, disposed at a portion of said cylinder adjacent to said at least one open end, processed to provide said cylinder with a reduced thickness portion for a socket joint;
• and
• a resinous terminal engaging member having a head fitted into said processed open end of said cylinder and having a plurality of discrete recesses formed circumferentially around a periphery of said terminal engaging member so as to be fastened to said at least one open end,
• wherein said terminal engaging member is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder at positions spaced circumferentially around said at least one open end of said cylinder such that a plurality of parts projects into said plurality of discrete recesses of said head, each of said plurality of parts thereby fixing a relative position between said cylinder and said terminal engaging member in both axial and rotational directions.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• a developing sleeve for developing a latent image formed on said electrophotographic photosensitive drum, said developing sleeve including a metallic cylinder having a wall thickness of 0.3-1.5 mm, having at least one open end, an inner surface at a portion of said cylinder adjacent said at least one open end and processed to provide said cylinder with a reduced thickness portion for a socket joint, and a resinous terminal engaging member fastened to said at least one open end of said cylinder, said terminal engaging member having a head that is fitted into said at least one open end of said cylinder and having a plurality of discrete recesses formed circumferentially around a periphery of said terminal engaging member;
• and
• a gear for receiving a drive force for rotating said developing sleeve,
• wherein said terminal engaging member is fastened to said at least one open end of said cylinder by bending and cutting said reduced thickness portion of said cylinder at positions spaced circumferentially around said at least one open end of said cylinder such that a plurality of parts projects into said plurality of discrete recesses, each of said plurality of parts thereby fixing a relative position between said cylinder and said terminal engaging member in both axial and rotational directions.