US5345206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moving coil actuator utilizing flux-focused interleaved magnetic circuit
Assignee: BEI Electronics Inc
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Filing: 1993-06-10
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Granted: 1994-09-06
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Expires: 2013-06-10
Abstract
Abstract A cylindrically-symmetrical moving coil linear actuator utilizes axially-magnetized cylindrical magnets to provide flux-focused interleaved magnetic circuits. The moving coil linear actuator includes a cylindrical shell that has a closed end and open end. A magnetic core is disposed within the shell to define an annular air gap between the shell and the core. The core includes a first set of axially-magnetized cylindrical permanent magnets having a first direction of magnetization and disposed in proximity to the closed end of the shell. A second set of axially-magnetized cylindrically permanent magnets has a second direction of magnetization which is opposite of the first direction of magnetization and is disposed in proximity to the open end of the shell. A first ferro-magnetic pole piece is disposed between the first set of magnets and the second set of magnets. A second ferro-magnetic pole piece is disposed between the second set of magnets and the open end of the shell. A moving coil assembly is disposed within the annular air gap. The coil assembly includes a non-magnetic coil carrier disposed within the air gap. A first coil winding is formed on the coil carrier in proximity to the first set of magnets and is wound to have a first polarity. A second coil winding is formed on the coil carrier in proximity to the second set of magnets and is wound to have a second polarity opposite to the first polarity such that the first and second coil windings are wound in series opposition.
Inventors
- 👤 Anthony C. Morcos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:34
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356; H01; H01F; H01F7/00; H01F7/06; H01F7/066
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
217 words
A moving coil linear actuator comprising: a cylindrical shell having a closed end and an open end; a core disposed within the shell to define an annular air gap therebetween, the core including first axially-magnetized cylindrical permanent magnet means having a first direction of magnetization and disposed in proximity to the closed end of the shell, second axially-magnetized cylindrical permanent magnet means having a second direction of magnetization opposite to the first direction of magnetization and disposed in proximity to the open end of the shell, a first ferro-magnetic pole piece disposed between the first magnet means and the second magnet means, and a second ferro-magnetic pole piece disposed between the second magnet means and the open end of the shell; and a coil assembly movably disposed within the annular air gap and connectable to an electrical power supply, the coil assembly including a coil carrier disposed within the annular air gap, a first coil winding formed on the coil carrier in proximity to the first magnet means and wound to have a first polarity, and a second coil winding formed on the coil carrier in proximity to the second magnet means and wound to have a second polarity opposite to the first polarity such that the first and second coil windings are wound in series opposition.
Claim 2
Dependent Claim
217 words
A moving coil linear actuator comprising: a cylindrical shell having a closed end and an open end; a core disposed within the shell to define an annular air gap therebetween, the core including first axially-magnetized cylindrical permanent magnet means having a first direction of magnetization and disposed in proximity to the closed end of the shell, second axially-magnetized cylindrical permanent magnet means having a second direction of magnetization opposite to the first direction of magnetization and disposed in proximity to the open end of the shell, a first ferro-magnetic pole piece disposed between the first magnet means and the second magnet means, and a second ferro-magnetic pole piece disposed between the second magnet means and the open end of the shell; and a coil assembly movably disposed within the annular air gap and connectable to an electrical power supply, the coil assembly including a coil carrier disposed within the annular air gap, a first coil winding formed on the coil carrier in proximity to the first magnet means and wound to have a first polarity, and a second coil winding formed on the coil carrier in proximity to the second magnet means and wound to have a second polarity opposite to the first polarity such that the first and second coil windings are wound in series opposition.
Claim 3
Dependent Claim
41 words
A moving coil linear actuator as in claim 1 wherein the first magnet means comprises a first plurality of disc-shaped permanent magnets placed in series and the second magnet means comprises a second plurality of disc-shaped permanent magnets placed in series.
Claim 4
Dependent Claim
25 words
A moving coil linear actuator as in claim 1 wherein the first magnet means is shorter in the axial direction than the second magnet means.
Claim 5
Dependent Claim
25 words
A moving coil linear actuator as in claim 3 wherein the first magnet means is one-half to three-quarters as long as the second magnet means.
Claim 6
Dependent Claim
180 words
A moving coil linear actuator comprising: a cylindrical shell having a closed end and an open end; a core disposed within the shell to define an annular air gap therebetween, the core including a plurality of sets of axially-magnetized cylindrical permanent magnets separated from one another by ferro-magnetic pole pieces and having alternating directions of magnetization, the sets of magnets including an innermost magnet set disposed in proximity to the closed end of the shell and an outermost magnet set disposed in proximity to the open end of the shell, the outermost magnet set having a ferro-magnetic pole piece disposed between said outermost magnet set and the open end of the shell; and a coil assembly movably disposed within the annular air gap, the coil assembly including a coil carrier disposed within the annular air gap and a plurality of coil windings formed on the coil carrier in axial correspondence to the plurality of sets of magnets, being wound to have alternating polarities such that adjacent coil windings are wound in series opposition, and connectable to an electrical power supply.
Claim 7
Dependent Claim
180 words
A moving coil linear actuator comprising: a cylindrical shell having a closed end and an open end; a core disposed within the shell to define an annular air gap therebetween, the core including a plurality of sets of axially-magnetized cylindrical permanent magnets separated from one another by ferro-magnetic pole pieces and having alternating directions of magnetization, the sets of magnets including an innermost magnet set disposed in proximity to the closed end of the shell and an outermost magnet set disposed in proximity to the open end of the shell, the outermost magnet set having a ferro-magnetic pole piece disposed between said outermost magnet set and the open end of the shell; and a coil assembly movably disposed within the annular air gap, the coil assembly including a coil carrier disposed within the annular air gap and a plurality of coil windings formed on the coil carrier in axial correspondence to the plurality of sets of magnets, being wound to have alternating polarities such that adjacent coil windings are wound in series opposition, and connectable to an electrical power supply.
Claim 8
Dependent Claim
28 words
A moving coil linear actuator as in claim 5 wherein each of the plurality of sets of magnets comprises a plurality of disc-shaped permanent magnets placed in series.
Claim 9
Dependent Claim
30 words
A moving coil linear actuator as in claim 5 wherein the innermost magnet set is shorter in the axial direction than the remainder of the plurality of sets of magnets.
Claim 10
Dependent Claim
30 words
A moving coil linear actuator as in claim 7 wherein the innermost magnet set is one-half to one-third as long as the remainder of the plurality of sets of magnets.
Claim 11
Dependent Claim
16 words
A moving coil linear actuator as in claim 5 wherein the magnets are rare earth magnets.
Claim 12
Dependent Claim
35 words
A moving coil linear actuator as in claim 5 wherein the magnets are rare earth magnets selected from the group consisting of SmCO 5 , Sm 2 CO 17 and Nd 2 Fe 14 B.
Claim 13
Dependent Claim
16 words
A moving coil linear actuator as in claim 5 wherein the pole pieces are iron alloys.
Claim 14
Dependent Claim
30 words
A moving coil linear actuator as in claim 5 wherein the pole pieces are iron alloys selected from the group consisting of cold-rolled steel, vanadium permendur and 400-series stainless steel.
Claim 15
Dependent Claim
25 words
A moving coil linear actuator as in claim 5 wherein the coil windings are copper or aluminum magnet wire having non-electrically conducting insulation formed thereon.
Claim 16
Dependent Claim
17 words
A moving coil linear actuator as in claim 5 wherein the coil carrier comprises a nonferromagnetic material.
Claim 17
Dependent Claim
27 words
A moving coil linear actuator as in claim 14 wherein the coil carrier comprises a nonferromagnetic material selected from the group consisting of fiberglass, paper and plastic.
Claim 18
Dependent Claim
17 words
A moving coil linear actuator as in claim 5 wherein the coil carrier comprises a non-magnetic metal.
Claim 19
Dependent Claim
29 words
A moving coil linear actuator as in claim 16 wherein the coil carrier comprises a non-magnetic metal selected from the group consisting of aluminum, titanium or 300-series stainless steel.
Claim 20
Dependent Claim
209 words
A moving coil actuator comprising: a shell having a closed end and an open end; a core disposed within the shell to define an air gap therebetween, the core including first axially-magnetized permanent magnet means having a first direction of magnetization and disposed in proximity to the closed end of the shell, second axially-magnetized permanent magnet means having a second direction of magnetization opposite to the first direction of magnetization and disposed in proximity to the open end of the shell, a first ferro-magnetic pole piece disposed between the first magnet means and the second magnet means, and a second ferro-magnetic pole piece disposed between the second magnet means and the open end of the shell; and a coil assembly movably disposed within the air gap and connectable to an electrical power supply, the coil assembly including a coil carrier disposed within the gap, a first coil winding formed on the coil carrier in proximity to the first magnet means and wound to have a first polarity, and a second coil winding formed on the coil carrier in proximity to the second magnet means and wound to have a second polarity opposite to the first polarity such that the first and second coil windings are wound in series opposition.
Claim 21
Dependent Claim
209 words
A moving coil actuator comprising: a shell having a closed end and an open end; a core disposed within the shell to define an air gap therebetween, the core including first axially-magnetized permanent magnet means having a first direction of magnetization and disposed in proximity to the closed end of the shell, second axially-magnetized permanent magnet means having a second direction of magnetization opposite to the first direction of magnetization and disposed in proximity to the open end of the shell, a first ferro-magnetic pole piece disposed between the first magnet means and the second magnet means, and a second ferro-magnetic pole piece disposed between the second magnet means and the open end of the shell; and a coil assembly movably disposed within the air gap and connectable to an electrical power supply, the coil assembly including a coil carrier disposed within the gap, a first coil winding formed on the coil carrier in proximity to the first magnet means and wound to have a first polarity, and a second coil winding formed on the coil carrier in proximity to the second magnet means and wound to have a second polarity opposite to the first polarity such that the first and second coil windings are wound in series opposition.
Claim 22
Dependent Claim
38 words
A moving coil actuator as in claim 18 wherein the first magnet means comprises a first plurality of permanent magnets placed in series and the second magnet means comprises a second plurality of permanent magnets placed in series.
Claim 23
Dependent Claim
24 words
A moving coil actuator as in claim 18 wherein the first magnet means is shorter in the axial direction than the second magnet means.
Claim 24
Dependent Claim
24 words
A moving coil actuator as in claim 20 wherein the first magnet means is one-half to three-quarters as long as the second magnet means.
Claim 25
Dependent Claim
174 words
A moving coil actuator comprising: a shell having a closed end and an open end; a core disposed within the shell to define an air gap therebetween, the core including a plurality of sets of axially-magnetized permanent magnets separated from one another by ferro-magnetic pole pieces and having alternating directions of magnetization, the sets of magnets including an innermost magnet set disposed in proximity to the closed end of the shell and an outermost magnet set disposed in proximity to the open end of the shell, the outermost magnet set having a ferro-magnetic pole piece disposed between said outermost magnet set and the open end of the shell; and a coil assembly movably disposed within the air gap, the coil assembly including a coil carrier disposed within the air gap and a plurality of coil windings formed on the coil carrier in axial correspondence to the plurality of sets of magnets, being wound to have alternating polarities such that adjacent coil windings are wound in series opposition, and connectable to an electrical power supply.
Claim 26
Dependent Claim
174 words
A moving coil actuator comprising: a shell having a closed end and an open end; a core disposed within the shell to define an air gap therebetween, the core including a plurality of sets of axially-magnetized permanent magnets separated from one another by ferro-magnetic pole pieces and having alternating directions of magnetization, the sets of magnets including an innermost magnet set disposed in proximity to the closed end of the shell and an outermost magnet set disposed in proximity to the open end of the shell, the outermost magnet set having a ferro-magnetic pole piece disposed between said outermost magnet set and the open end of the shell; and a coil assembly movably disposed within the air gap, the coil assembly including a coil carrier disposed within the air gap and a plurality of coil windings formed on the coil carrier in axial correspondence to the plurality of sets of magnets, being wound to have alternating polarities such that adjacent coil windings are wound in series opposition, and connectable to an electrical power supply.
Claim 27
Dependent Claim
26 words
A moving coil actuator as in claim 22 wherein each of the plurality of sets of magnets comprises a plurality of permanent magnets placed in series.
Claim 28
Dependent Claim
29 words
A moving coil actuator as in claim 22 wherein the innermost magnet set is shorter in the axial direction than the remainder of the plurality of sets of magnets.
Claim 29
Dependent Claim
30 words
A moving coil actuator as in claim 24 wherein the inner most magnet set is one-half to one-third as long as the remainder of the plurality of sets of magnets.
Claim 30
Dependent Claim
15 words
A moving coil actuator as in claim 22 wherein the magnets are rare earth magnets.
Claim 31
Dependent Claim
34 words
A moving coil actuator as in claim 22 wherein the magnets are rare earth magnets selected from the group consisting of SmCO 5 , Sm 2 CO 17 and Nd 2 Fe 14 B.
Claim 32
Dependent Claim
15 words
A moving coil actuator as in claim 22 wherein the pole pieces are iron alloys.
Claim 33
Dependent Claim
29 words
A moving coil actuator as in claim 22 wherein the pole pieces are iron alloys selected from the group consisting of cold-rolled steel, vanadium permendur and 400-series stainless steel.
Claim 34
Dependent Claim
24 words
A moving coil actuator as in claim 22 wherein the coil windings are copper or aluminum magnet wire having non-electrically conducting insulation formed thereon.
Claim 35
Dependent Claim
16 words
A moving coil actuator as in claim 22 wherein the coil carrier comprises a non-ferromagnetic material.
Claim 36
Dependent Claim
26 words
A moving coil actuator as in claim 31 wherein the coil carrier comprises a non-ferromagnetic material selected from the group consisting of fiberglass, paper and plastic.
Claim 37
Dependent Claim
16 words
A moving coil actuator as in claim 22 wherein the coil carrier comprises a non-magnetic metal.
Claim 38
Dependent Claim
28 words
A moving coil actuator as in claim 33 wherein the coil carrier comprises a non-magnetic metal selected from the group consisting of aluminum, titanium or 300-series stainless steel.
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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) | 1997-09-05 | 1998-03-07 | 1998-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-05 | 2002-03-07 | 2002-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-05 | 2006-03-07 | 2006-09-06 | $7700.00 | Window Closed / Lapsed |