Abstract: A data storage device has a pressurized flexible disc stack. An external actuator creates a partial split allowing a transducer to read edge codings on the discs to locate a desired one. An internal controller controls the pressure within the center of the stack and defines a zone aligned with the actuator within which the pressure is maintained above the bistable range while locating the desired disc. Upon locating the desired disc, the pressure with the zone is dropped below the upper limit of the bistable range causing the partial split to open or expand into a full, stable separation allowing a read/write head to access the desired disc.

Abstract: A hollow tubular actuator device operates through an enclosure formed by aligned holes in multiple floppy type storage disks. The disks, separated by interposed ventilating spacers, are clamped between inflexible end plates in a closely spaced continually rotating stack assembly. The actuator preferably rotates with the stack and translates axially relative to the disks and spacers. The actuator has a slotted opening for transmitting variable pressure to a selected spacer (address) in the stack and thereby varies the aggregate pressure equilibrium in the stack due to centrifugal air flow. This acts to deflect the orbits of disks peripherally, on either side of the selected address space, forming a gap useful for obtaining external access to otherwise inaccessible storage surfaces adjacent the selected space.

Abstract: A flexible disk magnetic recording device wherein a large number of disks are separated by mechanical splitting means to form a space between any two selected disks for the insertion of a read/write transducing head. A restraint device is placed in bearing contact with the outer surface of the deflected portion of the disk stack at the periphery to create a bending moment in the deflected disks to buckle the disks. The restraint is placed at approximately 90 degrees subsequent to the splitting means in the direction of disk rotation, subtends an arc at the disk periphery of approximately 10.degree.-40.degree. and extends inwardly from the periphery one-half to two-thirds the radius.

Abstract: In a flexible disk magnetic storage device, a suspension assembly for holding a transducing head in proper transducing relationship to a target disk regardless of the radial position of the track. The assembly incorporates a chamber which is filled with gaseous fluid and expanded in order to move a chamber enclosing member with a transducing head mounted thereon. The head is moved axially into transducing relationship with the disk surface and continues to move until the disk surface exerts counter-balancing axial forces on the head to prevent further movement. An escape path is provided so that a small amount of fluid continually escapes from the chamber equal to the rate at which fluid is introduced into the chamber when all axial forces are in balance. Such an assembly damps the rapidity of any change in axial position of the head induced by variations of the flexible disk surface away from a constant plane during rotation.

Abstract: Multiple (e.g. 500) ultra-thin flexible storage disks are stacked in a closely spaced configuration between circular end plates and arranged for rotation together with the plates about a common axis. Recording surfaces of the rotating disks are deflected to successively expand (open) and contract (close) a selected interface and thereby provide recording access at the expanded interface. Separation of the selected interfacing surfaces for access is facilitated by maintaining a predetermined air pressure between the contracted disks which conditions the rotation of the disks to bistability in the contracted position. Thus only a small initiating force is required to expand any selected interface with the disks initially contracted. This reduces disk wear. Expansion of a selected interface is accelerated (for shortening access time) by applying vacuum to the disks in synchronism with the initiating force.