US3581182A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital indicator step motor system
Assignee: RTX Corp
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Filing: 1967-02-08
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Granted: 1971-05-25
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Expires: 1987-02-08
Abstract
Abstract A digital indicator system in which a command signal activates a switching network selectively to couple digitally generated, bipolar, phase-displaced signals to the two-phase internal stator windings of a stepper motor having an outer permanent magnet rotor to cause the rotor always to step in the same direction no matter at what time the switching network is activated by the command signal. The rotor locks magnetically onto the stator poles of one phase when the input to the motor disappears. Miniature code drums driven by the stepper motor rotors provide feedback signals which are compared with the command signal to deactivate the switching network when the rotors reach the commanded positions.
Inventors
- 👤 David W Comstock
- 👤 Edwin R Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:39
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/40; G; G09; G09F; G09F11/00; G09F11/23; G09F11/235; H02K; H02K37/00; H02K37/10; H02K37/12; H03; H03M; H03M1/00; H03M1/12; H03M1/22; H03M1/24; H03M1/28; H03M1/30; H03M1/303; H03M1/305; H03M1/64
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
238 words
A digital indicator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one pluRality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means comprising means for applying a first potential of a certain value to said common terminal, means providing a second potential of a value less than that of the first potential and a third potential of a value greater than that of said first potential, and means for switching the other terminals of said phase windings between said second and third potentials.
Claim 2
Dependent Claim
238 words
A digital indicator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one pluRality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means comprising means for applying a first potential of a certain value to said common terminal, means providing a second potential of a value less than that of the first potential and a third potential of a value greater than that of said first potential, and means for switching the other terminals of said phase windings between said second and third potentials.
Claim 3
Dependent Claim
94 words
A system as in claim 1 in which said current flow producing means comprises means providing first and second phase-displaced switching signals, respective first and second switching means associated with said windings, means for applying the first switching signal to the first switching means for coupling the other terminal of the first winding alternately to the second potential and to the third potential and means for applying the second switching signal to the second switching means for coupling the other terminal of the second winding alternately to said second potential and said third potential.
Claim 4
Dependent Claim
86 words
A system as in claim 1 in which said switching means comprises first switching means for alternately producing current flow in one direction through said first winding and producing current flow in the other direction through said first winding, second switching means for alternately producing current flow in one direction through said second winding and for producing current flow in the other direction through said second winding, means providing respective phase-displaced first and second switching signals and means for applying said signals respectively to said windings.
Claim 5
Dependent Claim
21 words
A system as in claim 1 in which said current flow producing means comprising a common power source providing said potentials.
Claim 6
Dependent Claim
17 words
A system as in claim 1 in which said rotor is disposed radially outwardly of said stator.
Claim 7
Dependent Claim
236 words
A digital indicator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one plurality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means being normally disabled, said system including means producing a signal representing the actual position of said rotor, a source of a command signal representing a desired position of said rotor and means responsive to said actual position signal and to said command signal for enabling said current flow producing means when said actual position differs from said desired position.
Claim 8
Dependent Claim
236 words
A digital indicator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one plurality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means being normally disabled, said system including means producing a signal representing the actual position of said rotor, a source of a command signal representing a desired position of said rotor and means responsive to said actual position signal and to said command signal for enabling said current flow producing means when said actual position differs from said desired position.
Claim 9
Dependent Claim
204 words
A digital indiCator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one plurality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means comprising an oscillator having a certain frequency and means responsive to said oscillator for producing switching signals having a frequency substantially different from that of said oscillator.
Claim 10
Dependent Claim
204 words
A digital indiCator system including in combination a stator having a plurality of salient poles, a two-phase stator winding comprising a first phase winding carried by alternate ones of said stator poles and a second phase winding carried by the other stator poles, said windings having a common terminal, a permanent magnet rotor having a plurality of poles, one plurality of poles comprising twice the number of poles in the other plurality, means mounting said rotor and stator for relative rotary movement to a number of positions equal to the number of poles in the first plurality, and means for sequentially and successively producing current flow through said first and second phase windings in one direction, through said first phase winding in said one direction and through the second phase winding in another direction, through said first and second phase windings in said other direction and through said first phase winding in said other direction and through said second phase winding in said one direction to step said rotor through said positions, said current flow producing means comprising an oscillator having a certain frequency and means responsive to said oscillator for producing switching signals having a frequency substantially different from that of said oscillator.
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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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |