EP0084124A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Linear moving coil actuator
Assignee: International Business Machines Corp
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Filing: 1982-12-14
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Granted: —
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Expires: 2002-12-14
Abstract
Abstract The magnetic head actuator includes a substantially totally enclosed self-shielding voice coil linear motor which includes a continuous, cylindrical permanent magnet (18) of flexible material which is sealed against the inner cylindrical wall of the outer core (11) by a flared copper sleeve (29) that also serves as a non-magnetic, conductive shorted turn to reduce instantaneous inductance of the drive coil (35). An annular reluctance gap in the outer core provides symmetrical distribution of the permanent magnet flux.
Inventors
- 👤 Arthur Paul Brende
- 👤 Richard William Luoma
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 20:10
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
201 words
A linear actuator for positioning the transducer carriage assembly in a disk file comprising: a cylindrical outer core element (11) of magnetically permeable material; a cylindrical inner core element (14) of magnetically permeable material, coaxial and concentrically mounted within said outer core element; at least one axially extending slotted opening (38) in said inner core element; end closure means (13, 16) of magnetically permeable material associated with said core elements, whereby said core elements and said end closure means form a substantially totally enclosed annular space; a continuous cylindrical permanent magnet (18) within said annular space adjacent said outer core element inner wall in concentric relation therewith; a tubular retaining element (29) concentrically within said permanent magnet which retains said magnet against said outer core; a carriage supported for linear motion in the direction of the axis of said core elements with a portion thereof extending within said inner core element; a drive coil (35) substantially coaxial with said core elements and disposed in said annular space between said inner core element and said tubular retaining element; and connecting means (40) extending through said at least one slotted opening and interconnecting said drive coil and said carriage for unitary linear motion.
Claim 2
Dependent Claim
201 words
A linear actuator for positioning the transducer carriage assembly in a disk file comprising: a cylindrical outer core element (11) of magnetically permeable material; a cylindrical inner core element (14) of magnetically permeable material, coaxial and concentrically mounted within said outer core element; at least one axially extending slotted opening (38) in said inner core element; end closure means (13, 16) of magnetically permeable material associated with said core elements, whereby said core elements and said end closure means form a substantially totally enclosed annular space; a continuous cylindrical permanent magnet (18) within said annular space adjacent said outer core element inner wall in concentric relation therewith; a tubular retaining element (29) concentrically within said permanent magnet which retains said magnet against said outer core; a carriage supported for linear motion in the direction of the axis of said core elements with a portion thereof extending within said inner core element; a drive coil (35) substantially coaxial with said core elements and disposed in said annular space between said inner core element and said tubular retaining element; and connecting means (40) extending through said at least one slotted opening and interconnecting said drive coil and said carriage for unitary linear motion.
Claim 3
Dependent Claim
27 words
The linear actuator of claim 1 characterized in that a substantially annular slotted opening (41) is formed in one of said core elements providing a reluctance gap.
Claim 4
Dependent Claim
45 words
The linear actuator of claim 2 characterized in that said reluctance gap (41) is centrally located with respect to the axial length of said permanent magnet (18) with said gap being narrower than the thickness of the core element (11) through which it is formed.
Claim 5
Dependent Claim
27 words
The linear actuator of claim 1 characterized in that said tubular retaining element (29) is formed of a non-magnetic conductive material to also provide a shorted turn.
Claim 6
Dependent Claim
55 words
The linear actuator of claim 4 chracterized in that it further comprises annular sealing elements (24, 25) at each axial end of said permanent magnet and wherein said retaining element (29) comprises a copper tube flared at each end in cooperation with said annular sealing elements to seal said permanent magnet from said annular space.
Claim 7
Dependent Claim
39 words
The linear actuator of claim 5 characterized in that said copper tube is radially expanded to compressively retain said continuous permanent magnet (18) and said annular sealing elements against the inner cylindrical wall of said outer core element (11).
Claim 8
Dependent Claim
44 words
The linear actuator of claim 1 characterized in that said continuous cylindrical permanent magnet (18) comprises two sheets (21, 22) of flexible permanent magnet material, each cylindrically formed, concentrically positioned with respect to the other and radially magnetized with the abutting edges radially non-aligned.
References Cited (Backward Citations)
No citation records indexed.
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