Browse Prior Art Database

Magnetic Disk and Head Drives

IP.com Disclosure Number: IPCOM000086521D
Original Publication Date: 1976-Sep-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 52K

Publishing Venue

IBM

Related People

Porter, TH: AUTHOR [+2]

Abstract

Figs. 1 and 2 disclose a single stepping motor 20 effective, through shiftable change speed gearing 22, for either driving magnetic recording disk 24 or magnetic recording head 26. Figs. 3-7 show variations of this drive.

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Magnetic Disk and Head Drives

Figs. 1 and 2 disclose a single stepping motor 20 effective, through shiftable change speed gearing 22, for either driving magnetic recording disk 24 or magnetic recording head 26. Figs. 3-7 show variations of this drive.

Referring to Figs. 1 and 2, the change speed gearing 22 comprises a spool-shaped clutch member 28 which has clutch teeth 28a and 28b on its ends and is splined in output shaft 30 of motor 20.

Hub 32, which is fixed to disk 24, has clutch teeth 32a adapted to engage with clutch teeth 28a. Hub 34, which has clutch teeth 34a adapted to engage with clutch teeth 28b, is rotatably disposed on shaft 30 and is fixed to pinion gear 36, which is also rotatable on shaft 30. Gears 38, 40, 42 and 44 form a drive train between gear 36 and a gear segment 46 that is fixed by shaft 50 to access arm 48, which carries magnetic head 26.

Clutch member 28 is Shifted longitudinally by bell crank 52, swingably disposed about pin 54. An electromagnet 56 and a spring 58 act to swing bell crank 52, thereby moving clutch member 28.

The single stepping motor 20 may be used for either driving disk 24 or swinging arm 48 to move head 26 across the surface of disk 24. Electromagnet 56 is energized to swing bell crank 52 in order to move clutch member 28 to engage teeth 28a with teeth 32a, thus causing motor 20 to be directly connected to disk 24 for rotating the latter. Electromagnet 56 is deenergized to allow spring 58 to move bell crank 52 in the opposite direction in order to engage teeth 28b with teeth 34a for swinging arm 48 and head 26. The drive from motor output shaft 30 is then connected, through hub 34 and gears 36, 38, 40, 42 and 44 to gear segment 46. Motor output shaft 30 is driven in one direction or the other to move head 26 in opposite directions across disk 24.

Fig. 3 shows a variation of the above drive. It differs principally from the latter in that recording disk 24 is fixed at all times to motor shaft 30 so that, any time motor shaft 30 turns, disk 24 rotates. Disk 24 is fixed to shaft 30 by means of hub 32k. Clutch member 28k, which corresponds to clutch member 28, has teeth 28b, but not teeth 28a, which engage with teeth 34a of clutch member 34 to drive access arm 48 and head 26 across the surface of disk 24, in the manner described above.

Fig. 4 shows...