EP0055334A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic recording disk file
Assignee: International Business Machines Corp
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Filing: 1981-10-05
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Granted: —
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Expires: 2001-10-05
Abstract
Abstract A linear motor actuator for a magnetic read/write head has its stator located between a pair of disks within a stack of magnetic recording disks. The stator comprises an array of reversed polarity magnets 42,43 (preferably permanent) in a linear array, the two end magnets 42' being half the width of the others. A pair of flat coils 24, 25 are the drive elements of the armature of the motor with the coils arranged in side-by-side relationship for bridging from magnet to magnet of the stator, so that the armature will not stall between magnets. The actuator is controlled by an external microprocessor electronic control system for selecting any position precisely, rather than in steps as in a stepping motor. The microprocessor effects servo control of the actuator and its direction of motion based upon feedback signals. The stator arrangement including plates 41,42 and end magnets 42' reduce fringing flux thereby allowing said stator location between the associated pair of disks.
Inventors
- 👤 Richard Lawrence Garwin
- 👤 David Allen Thompson
- 👤 Robert Alan Scranton
- 👤 Thomas Kimber Worthington
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 10:44
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; H02K41/031; G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
35 words
Magnetic recording disk file including a magnetic recording head, characterised by said head (3) being driven by a linear motor (26, 49, 50) having its stator (42, 43) juxtaposed with a magnetic recording disk (1).
Claim 2
Dependent Claim
35 words
Magnetic recording disk file including a magnetic recording head, characterised by said head (3) being driven by a linear motor (26, 49, 50) having its stator (42, 43) juxtaposed with a magnetic recording disk (1).
Claim 3
Dependent Claim
162 words
Magnetic recording disk file including at least one magnetic recording disk (1), and a magnetic recording head (3), said head being driven reciprocably generally parallel to said disk from its center to its periphery by a linear motor having its stator (40) located adjacent to the surface of a disk in said disk file, said stator being constructed of a pair of magnetic yokes (41, 44) comprising parallel plates extending parallel to said disk, with at least one of said yokes (44) carrying an array of regularly spaced and alternating magnetic pole elements (42, 43) including distal poles at each end of said stator, the improvement comprising provision, at the ends of said array, of flux gathering end magnets (42) of permanent magnetic material having a flux producing capacity matched to collect the return flux from the poles adjacent to said distal poles of said stator, whereby fringing magnetic fields extending into the space in which said disk is located are minimize.
Claim 4
Dependent Claim
162 words
Magnetic recording disk file including at least one magnetic recording disk (1), and a magnetic recording head (3), said head being driven reciprocably generally parallel to said disk from its center to its periphery by a linear motor having its stator (40) located adjacent to the surface of a disk in said disk file, said stator being constructed of a pair of magnetic yokes (41, 44) comprising parallel plates extending parallel to said disk, with at least one of said yokes (44) carrying an array of regularly spaced and alternating magnetic pole elements (42, 43) including distal poles at each end of said stator, the improvement comprising provision, at the ends of said array, of flux gathering end magnets (42) of permanent magnetic material having a flux producing capacity matched to collect the return flux from the poles adjacent to said distal poles of said stator, whereby fringing magnetic fields extending into the space in which said disk is located are minimize.
Claim 5
Dependent Claim
23 words
A disk file in accordance with claim 2 wherein said end magnets produce substantially half the quantity of flux of said distal poles.
Claim 6
Dependent Claim
34 words
A disk file in accordance with any preceding claim, wherein said file includes a stack of a plurality of disks and said stator is located between a pair of said disks within said stack.
Claim 7
Dependent Claim
29 words
A disk file as claimed in any preceding claim in which said motor has multiple pairs of magnets including at least two pairs of aligned magnets on said stator.
Claim 8
Dependent Claim
21 words
A disk file as claimed in any preceding claim wherein the armature of said motor includes at least two flat coils.
Claim 9
Dependent Claim
49 words
A disk file as claimed in claim 6, wherein said motor includes a servo control system employing feedback and stored control signals for operating said coils in sequence as a function of head position and the difference between actual head position and a position command applied to said system.
Claim 10
Dependent Claim
69 words
A linear motor including an array of magnets of alternating polarity mounted upon a yoke, the improvement comprising an armature with a pair of flat magnetic coils and automatic control means for energizing said coils in sequence, sensor means for sensing actuator position, said automatic control means being adapted to control the sequence of energization signals to said coils as a function of the output of said sensor means.
Claim 11
Dependent Claim
69 words
A linear motor including an array of magnets of alternating polarity mounted upon a yoke, the improvement comprising an armature with a pair of flat magnetic coils and automatic control means for energizing said coils in sequence, sensor means for sensing actuator position, said automatic control means being adapted to control the sequence of energization signals to said coils as a function of the output of said sensor means.
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