US Patent 6208821 - Photosensitive Drum Having Injection Molded Insert and Method of Forming Same
A photosensitive drum is provided with an insert by injecting a rapidly curing material directly into the drum such that when the material cures, a noise/vibration reducing insert is provided. The insert material can be injected by a reciprocating nozzle during the manufacture/assembly of the drum. By injecting the insert material into the drum when the drum is being manufactured/assembled, it is not necessary to separately design the insert or to procure tooling to separately manufacture the insert. In addition, the insert will closely conform to the interior of the drum since the insert is molded inside of the drum. In addition, modifications to the insert (e.g., to vary the mass or size of the insert) are readily achievable without tooling modifications.
