Browse Prior Art Database

Servo Mechanism

IP.com Disclosure Number: IPCOM000074697D
Original Publication Date: 1971-May-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Lynott, JJ: AUTHOR [+2]

Abstract

In this magnetic memory device utilizing a plurality of coaxial data tracks, a servo mechanism actuates a magnetic head and positions it to a selected track. To achieve constant linear recording density the net centrifugal force of the head and a counterweight mass is used, which is responsive to changes of angular velocity.

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Servo Mechanism

In this magnetic memory device utilizing a plurality of coaxial data tracks, a servo mechanism actuates a magnetic head and positions it to a selected track. To achieve constant linear recording density the net centrifugal force of the head and a counterweight mass is used, which is responsive to changes of angular velocity.

Magnetic head 1 is mounted to rods 2, 3 of counterweight pistons 4, 5 within cylinders 6, 7. A counter balance 8 is mounted on rod 9 of piston 10 within cylinder 11 for axial movement. Variations in fluid pressure within the cylinders cause head 1 to move to various track locations.

Capstan assembly 12 comprises capstan head 13 to which cylinders 6, 7 and 11 are attached, as well as capstan body 14, and pulley 15, driven by variable speed motor 16.

Contained within capstan body 14 is counterweight reference cylinder 17 with hollowed-out piston 18 to receive nonlinear spring 19, which tends to force piston 18 upward. Also contained within capstan body 14 is counter-balance reference cylinder 20 with hollowed-out piston 21 to receive nonlinear spring 22 which tends to force piston 21 downward.

Cylinder 20 is hydraulically connected to cylinder 11 through tube 23. Cylinder 17 is hydraulically connected to cylinders 6, 7 through tube 24 and manifold 28.

Acting on the fluids are the force of spring 22 and centrifugal forces of counterbalance 8, rod 9, piston 10 in cylinder and 11, and the force of spring 19 and centrifugal forces o...