Browse Prior Art Database

Disk Counting and Position Sensing for Central Internal Selection

IP.com Disclosure Number: IPCOM000088690D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Orlando, AW: AUTHOR

Abstract

Fig. 1 shows a cross-section of a pack of co-rotating floppy-type storage disks 1 separated by metal spacer disks 3 having channels 5 (Fig. 2) which permit air to circulate radially from central space 7 into spaces 9 between the recording surfaces of the floppy disks. Centrally movable slotted piston member 11 conducts air transiently through slit 13 to the adjacent one of interface spaces 9 in a manner tending to produce pressure imbalance and deflect the disks apart at said space. This is used to facilitate introduction of a transportable transducing head into the widened space.

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Disk Counting and Position Sensing for Central Internal Selection

Fig. 1 shows a cross-section of a pack of co-rotating floppy-type storage disks 1 separated by metal spacer disks 3 having channels 5 (Fig. 2) which permit air to circulate radially from central space 7 into spaces 9 between the recording surfaces of the floppy disks. Centrally movable slotted piston member 11 conducts air transiently through slit 13 to the adjacent one of interface spaces 9 in a manner tending to produce pressure imbalance and deflect the disks apart at said space. This is used to facilitate introduction of a transportable transducing head into the widened space.

A magnetic reluctance position-sensing head l7,supported on member 11 in close proximity to slit 13, senses the inner edges of the storage and spacer disks. A high frequency current supplied to the position-sensing head encounters a reluctance which varies according to the presence of a storage or spacer disk adjacent the magnetic circuit gap of the head. The reluctance changes are detectable by circuits (not shown) and utilizable to provide counting indications associated with the head position. Obviously peripheral fluctuations of the storage disks do not affect this central position sensing operation. A capacitance sensing head can be used instead of the reluctance head. It is also possible to sense pressure variations inside the actuating member 11 as the member moves across the openings defined by the channels 5 in t...