Abstract: In a magnetic recording disc cartridge having a recording disc contained within an upper housing and a separably mating lower housing, an improved latch and carrying handle includes a handle pivotally mounted to the upper housing, lifting apparatus selectively engageable with the recording disc for moving the disc axially away from the lower housing and including a pivotally mounted lifting bar and connected disc engaging element, a latch slidably mounted to the lifting bar for connecting the lifting bar and the handle together for pivotal movement, and a trigger engageable with the latch for moving the latch to its handle engaging position.

Abstract: Apparatus for preventing unauthorized access to data recorded upon the magnetic discs of a disc drive which utilizes at least one rotating magnetic disc and at least one magnetic playback head movable relative to the axis of rotation of the disc to access data recorded on the disc includes structure selectively engageable and disengageable with the playback head for restraining the movement of the head, and locking structure for controlling the engagement and disengagement of the head movement restraining structure.

Abstract: In a disc drive for use with an operator inserted flexible magnetic recording disc cartridge means are disclosed for preventing closing of the cartridge access door and the disc clamping means if a recording disc cartridge is only partially inserted.

Abstract: Apparatus for centering and clamping a flexible magnetic recording disc in a disc drive comprises a spindle having on its outer end a face for supporting the associated recording disc and also has a recess within that face and a disc clamping element which cooperates with the spindle and includes a plurality of resiliently deflectable fingers extending in a direction both angularly outwardly of the axis and toward the spindle with means for deflecting the fingers radially outwardly for centering the associated recording disc with respect to the center of the spindle, and means for selectively moving the clamping element toward and away from the spindle and into and out of releasable engagement with the recording disc and spindle.

Abstract: A crash stop for use in a rotary disc file storage system, particularly for use with a rotary-type electromechanical actuator, the crash stop comprising a dual stop mechanism for delimiting the travel of an actuator arm in either of two reciprocal directions, the stop having two symetrically oriented plain levers having separate spaced pivots, the levers each having first segments projecting from the pivot and adjustably spaced on either side of a stop pin fixed on the actuator arm and second segments oppositely projecting from the pivot and interconnected by a spring loaded, adjustment mechanism, whereby movement of the actuator arm is restricted by contact of the stop pin with one of the first lever segments and limited compression of a spring in the adjustment mechanism.

Abstract: A recording head support assembly for use on a high density, direct access data storage device, the head support assembly having multiple arms rigidly interconnected in bank and attached to an actuator mechanism, and having at least one magnetic head flexibly mounted to each arm by a localized spring assembly for reduction of tolerances and maintenance of alignment.

Abstract: A multiple-stage sintering process is described for making low porosity manganese-zinc ferrites having good magnetic characteristics.

Abstract: A device and method are disclosed for testing the abrasion quality of a magnetic recording member to cause recording head wear. A magnetic recording member to be tested is moved past a dummy recording head, the smoothness of which has been determined before the head is contacted with the magnetic recording surface. After a predetermined contact between the dummy head and the tape, the smoothness of the head is again determined which is a direct function of the abrasion characteristics of the tape. The smoothness of the dummy head is determined by means of a non-contact photonic sensor which converts reflective light from the surface of the head into a specific voltage output.

Abstract: A reel for magnetic recording tape includes a hub having axially extending coaxial inner and outer rims joined by a radially extending web, and an intermediate ring on each side of the web extending axially outward of the web, and a pair of opposed flanges. The flanges are attached to and extend radially outward of the hub, and each flange has a pair of coaxial rings extending axially inward of the reel with the radially outer flange rings being received against the corresponding radially inward portion of the hub outer rim and the radially inner flange rings being received against the radially outward portion of the corresponding hub intermediate rings.

Abstract: A cartridge for holding and protecting a recording disc during storage and use is disclosed in which a recording head access door for providing access to the disc within the cartridge is attached to the cartridge housing by a hinge pivotally operable about a predetermined axis.

Abstract: A reel for magnetic recording tape includes a hub having axially extending coaxial inner and outer rims joined by a radially extending web, and an intermediate ring on each side of the web extending axially outwardly of the web and a pair of opposed flanges. The flanges are attached to and extend radially outwardly of the respective hub intermediate rings and each flange includes hub support means cooperating with its respectively adjacent hub intermediate ring and the hub outer rim to assist the hub outer rim in resisting radially inward deflection.

Abstract: A magnetic coating composition is disclosed which comprises a dispersion of magnetic particles in a solution of an epoxy resin having an average of between 1 and 3 epoxy groups per molecule and having an epoxy equivalent in the range about 400 to 4,000 and containing an organic acid which boils below 220.degree. C., the acid being present in amount equal to from 2 to 20% by weight of the contained magnetic particles. Magnetic recording media prepared by coating a substrate with the coating composition, subjecting the coated substrate to a magnetic field to orient the magnetic particles in a desired direction and then heating the coated substrate to evaporate the solvent and cure the resin exhibit high orientation ratios in the range 1.8 to 2.4.

Abstract: A servo system for controlling the movement of one or more magnetic transducer heads relative to rotating magnetic disc surfaces which are supported and transported by means of a linear actuator motor having position and velocity modes of control, and which additionally has an anticipatory mode of control which provides a compensatory signal proportional to the rate of change of the servo velocity error over the operating frequencies of the system so that the linear actuator motor is responsive to both the velocity error and compensatory mode signals to reduce velocity overshoots from a predetermined programmed velocity profile.

Abstract: A method and apparatus for recovering data stored on a magnetic medium which includes a variable frequency oscillator and a variable frequency oscillator feedback control loop therefor as a part of the data read circuitry, and which includes means for attempting to recover marginally recorded data by increasing the variable frequency oscillator feedback control loop gain during predetermined data read retries.

Abstract: A cassette container having a latch member connected to the top of the container by an integral, flexible hinge which latches against a pair of pins on the bottom of the container, the pins incorporating slots which receive a plastic locking seal therethrough to prevent an opening of the latch without destruction of the seal.

Abstract: A captive pivot nut is fastened to a panel either by a separate bolt or, in the case of a toggle switch, by being threaded onto the switch and a rocker arm is pivotably snapped onto the captive nut and actuates the switch by being pivoted about the nut to depress the switch, or, in the case of a toggle switch, the rocker arm is mounted over the switch toggle arm.