Abstract: A cutting blade replacement apparatus includes a nut attaching-detaching unit including a nut holding part that holds a nut and a drive part that rotates the nut holding part. When the nut is screwed to a male screw formed at an end part of a boss part of a cutting unit, one of the nut attaching-detaching unit or the cutting unit moves in a Y-axis direction in synchronization with the speed of movement in the Y-axis direction due to the screwing of the nut, and the other of the nut attaching-detaching unit and the cutting unit escapes in the Y-axis direction when a pressing force equal to or larger than a predetermined value acts on the nut attaching-detaching unit or the cutting unit.

Abstract: A card holder for a rotary type information retrieving device such as a telephone number list, address list, and so on, in which a plurality of information-containing card cases are hangingly supported between a pair of mutually spaced rotary discs. In the present invention, a plurality of pins are projectively provided on the mutually opposed surfaces of the pair of rotary discs around their circumference and at an equal space interval provided among them, and a plurality of the information-containing card cases are hangingly supported between the rotary discs by the inwardly projected pins thereon. Each card case is formed by folding a single sheet of film material into a folder shape, and its bent portion, either in a single U-shape or in a circular shape in its cross-section, is made a pin insertion engagement part.

Abstract: A rotary type index in which a multiplicity of information containing cards are arranged around a cylindrical drum and the drum is rotated to display information-containing surfaces of the cards in a viewing window is provided with a mechanism for causing a plurality of the information cards to be brought into position with a single selection key. This is as distinguished from the conventional drum type machine in which the number of selection switches equals the number of information cards.