Abstract: A telecommunications line test system wherein a digital telecommunications network is electronically sectionalized via at least one master test unit in combination with at least one remotely addressable field loopback unit whereby the defective line section is isolated by progressively looping back test data as transmitted from a master test unit. Each field loopback unit, when properly addressed, will loopback to both the near side and the far side of the line so as to enable a given loopback unit to be reset (inactivated) from either side of the line.

Abstract: A buffering device for use with a process cartridge disposed for detachable mounting in an image-forming apparatus. The buffering device is disposed for buffering the longitudinal movement of a photosensitive member relative to the casing of the process cartridge and, also if desired, for buffering the longitudinal movement of the process cartridge casing relative to a reference wall of the image-forming apparatus. The longitudinal movement is in response to rotation of a helical gear mounted on the rotatable photosensitive member by a helical gear on a drive shaft of the image-forming apparatus. The buffering device also is disposed for imparting a reciprocal longitudinal movement to the photosensitive member and the casing.