Abstract: A cartridge cover having slotted bosses which are positioned so that both the bosses and their slots are aligned with the vectorial resultant lines representing the direction of change that takes place during thermal expansion of the cartridge. Each boss has a fitting which engages pins fixed into the base of the cartridge, thereby securing the cover to the base. The cover and the base have different coefficients of thermal expansion. The slots are of sufficient length to allow all motion of the pins, taking place as a result of thermal expansion, to occur within the slots.

Abstract: A document storage and retrieval system featuring a plurality of remotely disposed control terminals arranged in data transfer relation to a computer includes a plurality of document storage units containing documents recorded on film. These units include means for converting an optical image of such documents to video signals. A plurality of video buffer units associated with each of the terminals are coupled by switching means to any one of the document storage units so that the video signals derived therefrom and representing the documents can be stored on a video buffer unit associated with a given terminal.

Abstract: A recording apparatus of a type employing a thin pliant disc of recording material with a transducer disposed to advance and retreat across the disc in recording relation thereto employs a drive construction for rotating the disc and a base member having a generally smooth crowned surface underlying the disc. The crowned surface includes a radially extending crest defined by flanking portions sloping away from the crest region formed therebetween. The crest extends linearly across the surface (preferably on a radius or diameter) of the disc. Means for rotating the disc relative to the underlying base member in surface following relation causes the recording surface of the disc to be subjected to tensioning forces derived from the conjoint change in angular direction of the disc and the change in the plane of movement of the disc as it passes across the crest region thereby smoothing uneven or irregular portions of the recording surface passing beneath the transducer.