Abstract: In an indexing mechanism for advancing a transducer with respect to a rotated disk to record and/or play back information on the disk, the transducer is mounted on a cylindrical carrier having a flat surface along one of its sides. A fixed guide supports the carrier for longitudinal movement along a reference axis defining the direction of travel of the carrier relative to the rotated disk. The carrier is moved by a stepper motor which rotates a lead screw in threading engagement with the carrier. A pair of flat support surfaces of the guide contact the flat surface of the carrier along respective parallel lines arranged parallel to the reference axis. Another flat support surface of the guide contacts the cylindrical portion of the carrier along a line arranged parallel to the first two lines. Thus a three-point support is provided for the carrier which prevents it from being rolled about the reference axis as the lead screw is rotated to move the carrier along the axis.

Abstract: In a camera, a pressure plate is urged against a film frame to hold the film frame in the focal plane of a picture-taking lens during exposure. A resiliently flexible strip, mounted on a loading door of the camera, is normally disposed in a storage plane. An actuating pin, which engages the flexible strip when the loading door is closed, connects the strip to camera mechanism, such as a shutter release. The actuating pin operates, in response to movement of the shutter release, to partially bow an intermediate portion of the strip from the storage plane by sliding a first portion of the strip in the storage plane toward a second, stationary portion of the strip. Bowing of the strip moves the intermediate portion toward the exposure plane to urge the pressure plate against the film frame before exposure and establishes a resilient force in the bowed portion for returning the strip to the storage plane after exposure.

Abstract: A carrier plate for use in mounting a pair of magnetic heads at diametrically opposite sides on a rotatable head drum section facilitates positioning adjustments to remove dihedral head positioning error. Independent dihedral position adjustment is made possible by virtue of a specially shaped slot in the carrier plate, which slot is characterized by two guide edges that are perpendicular to the head pair axis and are adapted to closely engage a shaft or other axis-identifying means associated with the drum section. Such guide edges in cooperation with the shaft permit relative movement between the carrier plate and drum section in a direction to correct dihedral error while blocking movement in directions which would disturb other alignment geometries. In a preferred implementation, the carrier plate has a generally disc-like form.

Abstract: A rotatable guide having both a conical and a cylindrical surface on opposite sides thereof is provided, within a coaxial-reel cassette, for orienting a magnetic tape along two different tape paths, depending on whether the tape is wound within the cassette between the coaxial reels or is withdrawn from the cassette and wrapped around a helical recording drum. By providing such a guide, with appropriate selective orientation, the tape may be translated directly between the reels by means of the conical surface, or guidedly directed to and from the recording drum, about which it helically wraps, by means of the cylindrical surface.