Patent US3638093A successfully refreshed from Google Patents.
US3638093A
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Magnetic suspension and propulsion system
Assignee: Rohr Inc
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Filing: 1971-04-19
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Granted: 1972-01-25
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Expires: 1991-04-19
Abstract
Abstract A method and apparatus for supporting and translating a mass by magnetic attractive means. A ferromagnetic track may have repetitive magnetic discontinuities. A linear plural-phase ferromagnetic electric motor, which may be synchronous, supports the mass at a small gap below the track at zero frequency current variation through the motor. The same motor translates the mass along the track at a speed determined by the frequency of the plural-phase alternating current supplied to the motor. A nonlinear feedback circuit having plural sensor elements controls the magnitude of the alternating current supplied to the motor. This maintains the gap substantially constant despite varying loads and gradually corrects for unevenness of the track. The feedback circuit provides uniform stability and uniform dynamic response regardless of the length of the gap.
Inventors
- 👤 James A Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:31
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; B; B60; B60L; B60L13/00; B60L13/04; B60L13/06; B60L13/10; B60L15/00; B60L15/002; B60L15/005; B61; B61B; B61B13/00; B61B13/12; B61B13/122; B61F; B61F5/00; B61F5/38; B61F5/383; B60L2200/00; B60L2200/26; B60L2220/00; B60L2220/10; B60L2220/14; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64; Y02T30/00
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
102 words
The method of suspending and moving a mass which includes the steps of; a. magnetically attracting said mass toward a stationary element in the direction opposite to the direction of the attraction due to gravity to define a gap therebetween, b. regulating the magnitude of the magnetic attraction exerted upon said mass by nonlinear electrical feedback related to the attracted position of the mass, and c. electrically altering the magnetic configuration associated with said mass transverse to the direction of attraction due to gravity to longitudinally move the position of stable magnetic equilibrium for said mass with respect to said stationary element.
Claim 2
Independent Claim
102 words
The method of suspending and moving a mass which includes the steps of; a. magnetically attracting said mass toward a stationary element in the direction opposite to the direction of the attraction due to gravity to define a gap therebetween, b. regulating the magnitude of the magnetic attraction exerted upon said mass by nonlinear electrical feedback related to the attracted position of the mass, and c. electrically altering the magnetic configuration associated with said mass transverse to the direction of attraction due to gravity to longitudinally move the position of stable magnetic equilibrium for said mass with respect to said stationary element.
Claim 3
Dependent Claim
2 words
said displacement,
Claim 4
Dependent Claim
2 words
said displacement,
Claim 5
Dependent Claim
31 words
The method of claim 1 in which; a. the magnitude of magnetic attraction is regulated by sensing the vertical position of the mass and the acceleration of change of that position.
Claim 6
Dependent Claim
33 words
The method of claim 1 in which; a. the magnetic configuration is altered by changing the magnetization of at least a part of said mass by passing plural-phase alternating electric current through it.
Claim 7
Dependent Claim
6 words
the velocity of said movements, and
Claim 8
Dependent Claim
6 words
the velocity of said movements, and
Claim 9
Dependent Claim
5 words
the acceleration of said movements.
Claim 10
Dependent Claim
5 words
the acceleration of said movements.
Claim 11
Dependent Claim
30 words
The method of claim 1 in which; a. the alternating current feedback gain of said electrical feedback is substantially constant as a function of the attracted position of the mass.
Claim 12
Dependent Claim
38 words
The method of claim 3, including the step of; a. controlling the amplitude of said plural-phase alternating current as a function of its frequency, whereby the feedback gain may be maintained substantially constant notwithstanding changes in the frequency.
Claim 13
Dependent Claim
41 words
The method of claim 1, including the additional step of; a. regulating the magnitude of the magnetic attraction exerted upon said mass by control of said nonlinear feedback to provide lateral stability of said mass with respect to said stationary element.
Claim 14
Dependent Claim
111 words
Magnetic suspension apparatus comprising; a. a stationary ferromagnetic member (2), b. a movable ferromagnetic member (1), disposed below said stationary member and defining a gap between said members, c. an electrical circuit (4, 38) associated with said movable member to produce a magnetic flux across said gap, d. a first sensor element (22) responsive to the length of said gap, e. a second sensor element (20) responsive to motion of said movable member, and f. a nonlinear feedback circuit (24, 26) including said first and second sensor elements and connected to said electrical circuit for the electrical control of said electrical circuit over a wide range of length of said gap.
Claim 15
Dependent Claim
111 words
Magnetic suspension apparatus comprising; a. a stationary ferromagnetic member (2), b. a movable ferromagnetic member (1), disposed below said stationary member and defining a gap between said members, c. an electrical circuit (4, 38) associated with said movable member to produce a magnetic flux across said gap, d. a first sensor element (22) responsive to the length of said gap, e. a second sensor element (20) responsive to motion of said movable member, and f. a nonlinear feedback circuit (24, 26) including said first and second sensor elements and connected to said electrical circuit for the electrical control of said electrical circuit over a wide range of length of said gap.
Claim 16
Dependent Claim
46 words
The apparatus of claim 7 in which; a. the magnetic flux across said gap is developed by alternating current applied to said electrical circuit, and b. the output of said feedback circuit is a direct current control voltage to control the magnitude of said alternating current.
Claim 17
Dependent Claim
32 words
The apparatus of claim 8 in which; a. said stationary member is an elongated rail, and b. said movable member includes means to shift the position of stable equilibrium along said rail.
Claim 18
Dependent Claim
62 words
The apparatus of claim 7, in which; a. said stationary ferromagnetic member is a rail having repetitive magnetic discontinuities, and b. said electrical circuit has plural paths (11, 12, 13) to carry plural-phase electric current to progressively alter the position of stable magnetic equilibrium of said movable member wIth respect to said rail for translating said movable member (1) along said rail.
Claim 19
Dependent Claim
43 words
The apparatus of claim 10 in which; a. said electrical circuit is wound (11, 12, 13) for plural phases of electricity, and b. said magnetic discontinuities are spaced to include a part of said electrical circuit which carries all of said plural phases.
Claim 20
Dependent Claim
20 words
The apparatus of claim 10 in which; a. the plurality of the plural-phase paths of said electrical circuit is three.
Claim 21
Dependent Claim
71 words
The apparatus of claim 7 in which; a. said stationary ferromagnetic member is a rail having discrete repetitive electrical paths, and b. said electrical circuit has plural paths (11, 12, 13) to carry plural-phase electric current, to induce electric current in said electrical paths for progressively altering the position of stable magnetic equilibrium of said movable member (1) with respect to said rail to translate said movable member along said rail.
Claim 22
Dependent Claim
43 words
The apparatus of claim 13 which includes; a. electrical discontinuity conductors (115) transverse to said rail, and b. longitudinal shorting conductors (116, 117), the electrical conductivity of said conductors and said shorting conductors being greater than the transverse electrical conductivity of said rail.
Claim 23
Dependent Claim
58 words
The apparatus of claim 7, which additionally includes; a. a uniform electrical conductor (2'''''') substantially coextensive with and attached to the underside of said stationary ferromagnetic member (2) to lie within said gap, whereby said magnetic flux induces electric currents in said uniform electrical conductor to magnetically propel said movable ferromagnetic member (1) along said stationary ferromagnetic member.
Claim 24
Dependent Claim
89 words
The apparatus of claim 7, which additionally includes; a. further plural-phase windings (111, 112, 113) repetitively disposed along said stationary elongated ferromagnetic member (2), b. means to energize said further plural-phase windings with plural-phase electric current, and c. electrically reactive means to alter the phase of electric current flowing in said electrical circuit (4, 38) by induction from said further plural-phase windings from the phase of the electric current flowing in said further plural-phase windings, whereby electric power is transmitted from said further plural-phase windings to said electrical circuit.
Claim 25
Dependent Claim
44 words
The apparatus of claim 7 in which; a. said stationary ferromagnetic member (2) is magnetically uniform and homogeneous, is magnetically retentive, and exhibits magnetic hysteresis, whereby a longitudinal force is exerted upon said motor (1) upon electric current flowing through the electric circuit thereof.
Claim 26
Dependent Claim
16 words
The apparatus of claim 7 in which; a. said movable ferromagnetic member (1) is longitudinally laminated.
Claim 27
Dependent Claim
16 words
The apparatus of claim 7 in which a. said stationary ferromagnetic member (2) is longitudinally laminated.
Claim 28
Dependent Claim
31 words
The apparatus of claim 7, in which said nonlinear feedback circuit includes; a. an electrical element (24) having an electrical output proportional to a mathematical root of the electrical input thereto.
Claim 29
Dependent Claim
31 words
The apparatus of claim 7, in which said nonlinear feedback circuit includes; a. another electrical element (26) having an electrical output proportional to a mathematical differential of the electrical input thereto.
Claim 30
Dependent Claim
129 words
The apparatus of claim 7, in which the nonlinear feedback circuit includes; a. an electrical integrator (58, 59, 61) connected to said first sensor element (22) responsive to the length of the gap, b. said integrator and also said second sensor element (20) responsive to acceleration connected to a first electrical element (24) having an electrical output proportional to a mathematical root of the electrical input thereto, c. the electrical output of said root element connected to a second electrical element (26) having an electrical output proportional to the mathematical differential of the electrical input thereto, and d. the output of said second electrical element connected to said electrical circuit (35, 36, 37, 38 4) associated with said movable ferromagnetic member (1) for the control of said electrical circuit.
Claim 31
Dependent Claim
47 words
The apparatus of claim 7, in which said electrical circuit includes; a. a variable frequency plural-phase oscillator (31) to originate alternating electrical energy for energizing said electrical circuit (38, 4) at a selected frequency corresponding to the desired velocity of translation of said movable ferromagnetic member (1).
Claim 32
Dependent Claim
64 words
The apparatus of claim 23, in which said electrical circuit additionally includes; a. an imperfect differentiator (32, 33 or 34) connected to each output phase circuit if said plural-phase oscillator (31), and to said electrical circuit (38, 4), to give an increasing voltage output with increasing frequency for overcoming the inductive reactance of said electrical circuit (4) associated with said movable ferromagnetic member (1).
Claim 33
Dependent Claim
90 words
The apparatus of claim 23, in which said electrical circuit additionally includes; a. plural electrical multipliers (35, 36, 37), each having, b. a first input circuit ( phi A, phi B, phi C) connected to an output phase circuit of said plural-phase oscillator (31), c. a second input circuit (Y) connected to said nonlinear feedback circuit, and d. an output circuit connected to said electrical circuit (38, 4) for energizing said electrical circuit proportional to the product of the electrical amplitudes derived from both said oscillator and said feedback circuit.
Claim 34
Dependent Claim
84 words
Magnetic suspension apparatus comprising; a. alternating current energized electromagnetic means for freely suspending a mass by magnetic attraction against the force of gravity acting thereon, b. sensing means carried by the mass for sensing movements thereof away from a reference position, and c. feedback means including said sensing means for regulating the magnitude of the alternating current energization in accordance with movements sensed by the sensing means to thereby restore the mass to its reference position over a range of frequency upwards from zero.
Claim 35
Dependent Claim
84 words
Magnetic suspension apparatus comprising; a. alternating current energized electromagnetic means for freely suspending a mass by magnetic attraction against the force of gravity acting thereon, b. sensing means carried by the mass for sensing movements thereof away from a reference position, and c. feedback means including said sensing means for regulating the magnitude of the alternating current energization in accordance with movements sensed by the sensing means to thereby restore the mass to its reference position over a range of frequency upwards from zero.
Claim 36
Dependent Claim
27 words
The apparatus of claim 26 wherein; a. the feedback means generates a direct current feedback voltage for control of the magnitude of the alternating current energization currents.
Claim 37
Dependent Claim
39 words
The apparatus of claim 27 wherein; a. said feedback voltage includes a control parameter to compensate for changes in the total weight of said mass to thereby restore the same to said reference position notwithstanding said changes in weight.
Claim 38
Dependent Claim
23 words
The apparatus of claim 27 wherein; a. the feedback voltage includes a control parameter responsive to the velocity of movement of the mass.
Claim 39
Dependent Claim
23 words
The apparatus of claim 27 wherein; a. the feedback voltage includes a control parameter responsive to the acceleration of movement of the mass.
Claim 40
Dependent Claim
25 words
The apparatus of claim 27 wherein; a. the feedback voltage includes a control parameter responsive to the displacement of the object from its reference position.
Claim 41
Dependent Claim
33 words
The apparatus of claim 27 wherein; a. the feedback voltage in response to said movements varies as the product of displacement of the mass from said reference position times the algebraic sum of
Claim 42
Dependent Claim
33 words
The apparatus of claim 32 wherein; a. said displacement is a dominant factor affecting the feedback voltage when the frequency of changes in displacement is in the range from dc to 1.2 hertz.
Claim 43
Dependent Claim
32 words
The apparatus of claim 32 wherein; a. said acceleration is a dominant factor affecting the feedback voltage when the frequency of changes in said displacement is in the range above 1.2 hertz.
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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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |