Patent US2253539A successfully refreshed from Google Patents.
Patent US3666977A successfully refreshed from Google Patents.
US3666977A
Expired / Lapsed
US
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Linear positioner
Assignee: Unisys Corp
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Filing: 1970-09-10
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Granted: 1972-05-30
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Expires: 1990-09-10
Abstract
Abstract A linear positioner particularly useful for rapidly and precisely positioning heads with respect to a magnetic disc recording surface. The positioner includes a linear motor having a cylindrical core of magnetically permeable material and a motor housing, also of permeable material, closely magnetically coupled to the ends of the core. Permanent magnets are mounted on the inner surface of the housing, between the ends thereof, to produce a magnetic field across an air gap to the core which is of substantially uniform density along the length of the core. A coil assembly, including a rigid edge-wound drive coil mounted around the core in the air gap, is supported for horizontal movement along the core by a plurality of roller bearings. The roller bearings are mounted on bearing support rods secured to the drive coil structure and spaced around the circumference thereof. Some of the bearings are mounted for rotation about vertical spindle axes so as to engage vertical rail surfaces while other bearings are mounted for rotation about horizontal spindle axes so as to engage horizontal rail surfaces. At least some of the bearings are flexibly mounted in order to preload the bearings and assure that they roll properly on the rail surfaces.
Inventors
- 👤 Clifford J Helms
- 👤 Stelios B Papadopoulos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
207 words
A linear motor comprising: a substantially cylindrical core of magnetically permeable material; a substantially cylindrical housing of magnetically permeable material mounted with the axis thereof coincident with the axis of said core, said housing including end portions formed to provide a low reluctance path to the ends of said core and an intermediate portion spaced from an intermediate portion of said core; a permanent magnet structure mounted within said housing adjacent to said intermediate portion thereof and spaced from said core to define an air gap therebetween, said permanent magnet structure being oriented so as to direct magnetic flux in a uniform direction substantially perpendicularly across said air gap; a rigid substantially shaped drive coil assembly; said housing including three elongated slots spaced by substantially 120* around the circumference thereof, each extending parallel to said core axis; a plurality of roller bearings secured to said drive coil assembly in alignment with said slots for rotation about spindle axes extending substantially perpendicular to planes through said core axis; and three fixedly mounted rails defining perpendicularly related reference surfaces, each reference surface engaging at least one of said roller bearings for supporting said coil assembly in said air gap out of engagement with said core and permanent magnet structure.
Claim 2
Dependent Claim
207 words
A linear motor comprising: a substantially cylindrical core of magnetically permeable material; a substantially cylindrical housing of magnetically permeable material mounted with the axis thereof coincident with the axis of said core, said housing including end portions formed to provide a low reluctance path to the ends of said core and an intermediate portion spaced from an intermediate portion of said core; a permanent magnet structure mounted within said housing adjacent to said intermediate portion thereof and spaced from said core to define an air gap therebetween, said permanent magnet structure being oriented so as to direct magnetic flux in a uniform direction substantially perpendicularly across said air gap; a rigid substantially shaped drive coil assembly; said housing including three elongated slots spaced by substantially 120* around the circumference thereof, each extending parallel to said core axis; a plurality of roller bearings secured to said drive coil assembly in alignment with said slots for rotation about spindle axes extending substantially perpendicular to planes through said core axis; and three fixedly mounted rails defining perpendicularly related reference surfaces, each reference surface engaging at least one of said roller bearings for supporting said coil assembly in said air gap out of engagement with said core and permanent magnet structure.
Claim 3
Dependent Claim
30 words
The motor of claim 1 wherein said drive coil assembly includes a first conductor having a substantially rectangular cross-section and wound on edge to form a cylindrical multi-turn drive coil.
Claim 4
Dependent Claim
28 words
The motor of claim 2 wherein said drive coil assembly includes rigid thin wall, cylindrical skins adhered to the inner and outer surfaces of said cylindrical drive coil.
Claim 5
Dependent Claim
90 words
The motor of claim 2 including a second conductor having a substantially rectangular cross-section and wound on edge on said core to form a cylindrical multi-turn bucking coil; said bucking coil having a greater number of turns than said drive coil; and first and second spaced means carried by said coil structure electrically contacting said bucking coil across a portion including a number of turns substantially equal to the number of turns in said drive coil for connecting said bucking coil portion in series of opposition to said drive coil.
Claim 6
Dependent Claim
52 words
The motor of claim 1 including three bearing support rods extending parallel to said core axis and secured to said drive coil assembly substantially 120* apart; and wherein said pluraliTy of roller bearings includes three sets of roller bearings, each set being mounted on a different one of said bearing support rods.
Claim 7
Dependent Claim
33 words
The motor of claim 5 wherein at least one of said sets of bearings includes first and second bearings mounted for rotation about first and second spindle axes extending perpendicular to one another.
Claim 8
Dependent Claim
25 words
The motor of claim 6 wherein at least one of said rails includes first and second perpendicular surfaces respectively engaging such first and second bearings.
Claim 9
Dependent Claim
58 words
The motor of claim 1 wherein said plurality of bearings includes a first group rotatable about spindle axes extending in a first direction perpendicular to a plane through said core axis and a second group rotatable about spindle axes extending in a second direction perpendicular to both said first direction and to a plane through said core axis.
Claim 10
Dependent Claim
54 words
The motor of claim 8 wherein said plurality of rails defines at least first and second spaced surfaces extending parallel to said first direction each engaging bearings in said first group disposed therebetween and third and fourth spaced surfaces extending parallel to said second direction each engaging bearings in said second group disposed therebetween.
Claim 11
Dependent Claim
39 words
The motor of claim 9 including means flexibly mounting at least one bearing in each of said first and second groups for respectively resiliently urging said flexibly mounted bearings against rail surfaces extending in said first and second directions.
Claim 12
Dependent Claim
24 words
The motor of claim 10 including adjustable stop means mounted adjacent each of said flexibly mounted bearings for limiting the amount of flexure thereof.
Claim 13
Dependent Claim
17 words
The motor of claim 1 including means for adjusting the position of one of said spindle axes.
Claim 14
Dependent Claim
27 words
The motor of claim 1 including energy absorbing bumper means secured in said housing adjacent to the end portions thereof in alignment with said drive coil assembly.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |