Browse Prior Art Database

Obtaining Uniform Openings in a Flexible Disk File

IP.com Disclosure Number: IPCOM000085684D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Barbeau, RA: AUTHOR [+3]

Abstract

Large packs of centrally clamped floppy disks rotating at high speeds can be separated for external transducing access in what is termed a bistable mode. Successive storage disks are spaced slightly apart by spacer elements, which permit central circulation of air through aligned apertures in the disks and radial circulation of air through porous spacers between the disks.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 67% of the total text.

Page 1 of 2

Obtaining Uniform Openings in a Flexible Disk File

Large packs of centrally clamped floppy disks rotating at high speeds can be separated for external transducing access in what is termed a bistable mode. Successive storage disks are spaced slightly apart by spacer elements, which permit central circulation of air through aligned apertures in the disks and radial circulation of air through porous spacers between the disks.

When the pressure condition of the circulating air is reduced below a critical level empirically determined, the rotating disks can be bent peripherally by small transient forces. The space formed by such bending can be made wide enough to accommodate an externally transported head. The pack may be closed (i.e., the disks may be restored to a uniform spacing) by increasing the internal pressure above the above-mentioned critical level.

The width of the access opening produced under the foregoing conditions is subject to variation over the range of all accessible positions in a pack. This condition is undesirable because the access time is a function of the "worst case" (widest) opening. Thus, if the narrowest opening in the range of all accessible file positions is made sufficiently wide to accommodate the head, the widest opening in the range will be considerably wider and take more time to form. This condition is corrected by a baffle structure described next.

The baffling construction shown in the figure reduces air pressure gradients which...