US3617841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-synchronizing direct current brushless motor
Assignee: Brailsford and Co Inc
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Filing: 1968-10-31
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Granted: 1971-11-02
•
Expires: 1988-10-31
Abstract
Abstract The disclosed invention is a synchronized motor operated by direct current and having a synchronizer in the form of a mechanical oscillator. The motor has a permanent magnet rotor and stator coils commutated by solid-state elements to produce magnetic pulses properly phased to keep the rotor turning. The mechanical oscillator has a member that oscillates at a natural frequency in response to the interaction of a permanent magnet and the pulsed field of a driving coil. The driving coil is connected to the stator coil section of the motor to receive a pulse, or oscillatory, driving signal therefrom. A pickup coil is energized by the oscillating member to produce a feedback signal at the natural frequency of the oscillating member, and this feedback signal is connected to the solid-state elements to control the timing of magnetic pulses in the stator coils thereby synchronizing the rotor speed in step with the natural frequency of the mechanical oscillator.
Inventors
- 👤 Harrison D Brailsford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:05
CPC Classifications
G; G04; G04C; G04C3/00; G04C3/16; G04C3/165; H; H02; H02K; H02K29/00
Claims Analysis
Total Claims: 60
Claim 1
Independent Claim
7 words
The combination comprising: A. A motor comprising:
Claim 2
Dependent Claim
7 words
The combination comprising: A. A motor comprising:
Claim 3
Dependent Claim
3 words
Main coil means,
Claim 4
Dependent Claim
3 words
Main coil means,
Claim 5
Dependent Claim
13 words
An oscillating member magnetically separated from said rotor and having a natural frequency,
Claim 6
Dependent Claim
13 words
An oscillating member magnetically separated from said rotor and having a natural frequency,
Claim 7
Dependent Claim
3 words
A permanent magnet,
Claim 8
Dependent Claim
3 words
A permanent magnet,
Claim 9
Dependent Claim
2 words
A rotor,
Claim 10
Dependent Claim
2 words
A rotor,
Claim 11
Dependent Claim
18 words
The invention as defined in claim 1 in which said permanent magnet is mounted on said oscillating member.
Claim 12
Dependent Claim
3 words
A permanent magnet,
Claim 13
Dependent Claim
3 words
A permanent magnet,
Claim 14
Dependent Claim
3 words
A permanent magnet,
Claim 15
Dependent Claim
3 words
A permanent magnet,
Claim 16
Dependent Claim
18 words
First and second coils connected, respectively, in series with the output circuits of said first and second transistors,
Claim 17
Dependent Claim
18 words
First and second coils connected, respectively, in series with the output circuits of said first and second transistors,
Claim 18
Dependent Claim
65 words
A second part stationarily mounted substantially concentrically with respect to said pickup coil; and B. Said oscillating member comprises a two-tyned tuning fork of ferromagnetic material to be actuated by the combined fields of said driving coil and said first part of said permanent magnet and to effect an oscillating change in flux from said second part of said permanent magnet linking said pickup coil.
Claim 19
Dependent Claim
65 words
A second part stationarily mounted substantially concentrically with respect to said pickup coil; and B. Said oscillating member comprises a two-tyned tuning fork of ferromagnetic material to be actuated by the combined fields of said driving coil and said first part of said permanent magnet and to effect an oscillating change in flux from said second part of said permanent magnet linking said pickup coil.
Claim 20
Dependent Claim
70 words
A feedback circuit connecting the output circuit of said first transistor to the base of said second transistor and the output circuit of said second transistor to the base of said first transistor, said main coil means comprising first and second coils connected to said output circuits of said first and second transistors, respectively; and B. Said feedback coil is connected to said base electrodes of both of said transistors.
Claim 21
Dependent Claim
70 words
A feedback circuit connecting the output circuit of said first transistor to the base of said second transistor and the output circuit of said second transistor to the base of said first transistor, said main coil means comprising first and second coils connected to said output circuits of said first and second transistors, respectively; and B. Said feedback coil is connected to said base electrodes of both of said transistors.
Claim 22
Dependent Claim
2 words
A rotor,
Claim 23
Dependent Claim
2 words
A rotor,
Claim 24
Dependent Claim
34 words
Solid-state commutating means comprising output terminals connected to said coil means to permit current pulses to energize said coil means in proper phase to keep said rotor turning; and B. A mechanical oscillator comprising:
Claim 25
Dependent Claim
34 words
Solid-state commutating means comprising output terminals connected to said coil means to permit current pulses to energize said coil means in proper phase to keep said rotor turning; and B. A mechanical oscillator comprising:
Claim 26
Dependent Claim
65 words
The invention as defined in claim 2 in which said driving coil and said pickup coil are mounted on opposite sides of said oscillating member; and said permanent magnet is divided into first and second parts and mounted transversely on said oscillating member with like poles of one polarity facing each other and like poles of the opposite polarity facing said driving and pickup coils.
Claim 27
Dependent Claim
60 words
A driving coil directly connected to said output circuits of said first and second transistors to receive an impulse signal at a frequency corresponding to the frequency of said current impulses, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 28
Dependent Claim
60 words
A driving coil directly connected to said output circuits of said first and second transistors to receive an impulse signal at a frequency corresponding to the frequency of said current impulses, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 29
Dependent Claim
42 words
A common junction to connect said first and second coils to a source of direct current to supply current impulses alternately to said first and second coils under the control of said first and second transistors, and B. A mechanical oscillator comprising:
Claim 30
Dependent Claim
42 words
A common junction to connect said first and second coils to a source of direct current to supply current impulses alternately to said first and second coils under the control of said first and second transistors, and B. A mechanical oscillator comprising:
Claim 31
Dependent Claim
46 words
A driving coil directly connected to said output terminals of said solid-state means to be energized thereby, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 32
Dependent Claim
46 words
A driving coil directly connected to said output terminals of said solid-state means to be energized thereby, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 33
Dependent Claim
34 words
Solid-state commutating means comprising output terminals connected to said coil means to permit current pulses to energize said coil means in proper phase to keep said rotor turning; and B. A mechanical oscillator comprising:
Claim 34
Dependent Claim
34 words
Solid-state commutating means comprising output terminals connected to said coil means to permit current pulses to energize said coil means in proper phase to keep said rotor turning; and B. A mechanical oscillator comprising:
Claim 35
Dependent Claim
46 words
A driving coil directly connected to said output terminals of said solid-state means to be energized thereby, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 36
Dependent Claim
46 words
A driving coil directly connected to said output terminals of said solid-state means to be energized thereby, said impulse signal in said driving coil producing an impulse magnetic field which interacts with the magnetic field of said permanent magnet to cause said oscillating member to oscillate,
Claim 37
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 38
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 39
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 40
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 41
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 42
Dependent Claim
18 words
A pickup coil energized by said oscillating member to produce a feedback signal at said natural frequency, and
Claim 43
Dependent Claim
40 words
The invention as defined in claim 3 comprising, in addition: first and second permanent stationary magnets oriented so that their fields oppose, respectively, the fields of said first and second parts, whereby the movement of said oscillating member is opposed.
Claim 44
Dependent Claim
43 words
A connection from said pickup coil to said bases of said transistors to make the output circuits of transistors alternately conductive in synchronous relation with said feedback signal to control the repetition rate of said current impulses in said first and second coils.
Claim 45
Dependent Claim
43 words
A connection from said pickup coil to said bases of said transistors to make the output circuits of transistors alternately conductive in synchronous relation with said feedback signal to control the repetition rate of said current impulses in said first and second coils.
Claim 46
Dependent Claim
25 words
A connection from said pickup coil to said solid-state means to control the commutation of said current pulses in synchronous relation with said feedback signal.
Claim 47
Dependent Claim
25 words
A connection from said pickup coil to said solid-state means to control the commutation of said current pulses in synchronous relation with said feedback signal.
Claim 48
Dependent Claim
25 words
A connection from said pickup coil to said solid-state means to control the commutation of said current pulses in synchronous relation with said feedback signal.
Claim 49
Dependent Claim
25 words
A connection from said pickup coil to said solid-state means to control the commutation of said current pulses in synchronous relation with said feedback signal.
Claim 50
Dependent Claim
36 words
The invention as defined in claim 4 comprising, in addition: adjustable mounting means for said stationary magnets to move them toward or away from said first and second parts to change said natural frequency is adjusted.
Claim 51
Dependent Claim
32 words
The invention as defined in claim 4 in which said oscillating member comprises a single, flat reed flexible substantially only in a direction toward and away from said driving and pickup coils.
Claim 52
Dependent Claim
30 words
The invention as defined in claim 4 in which said driving and pickup coils are solenoid coils substantially axially aligned with each other and with said first and second parts.
Claim 53
Dependent Claim
24 words
The invention as defined in claim 7 in which said first and second stationary magnets are located within said driving and pickup coils, respectively.
Claim 54
Dependent Claim
46 words
The invention as defined in claim 3 in which said oscillating member comprises a tuning fork having two tynes and said tynes facing said driving coil and said second part of said permanent magnet is mounted on the other of said tynes facing said pickup coil.
Claim 55
Dependent Claim
16 words
The invention as defined in claim 1 in which: A. Said permanent magnet is divided into:
Claim 56
Dependent Claim
14 words
The invention as described in claim 1 in which: A. Said solid-state means comprise:
Claim 57
Dependent Claim
7 words
The combination comprising; A. A circuit comprising:
Claim 58
Dependent Claim
7 words
The combination comprising; A. A circuit comprising:
Claim 59
Dependent Claim
20 words
The invention as described in claim 12 in which said feedback coil is connected in series between said base electrodes.
Claim 60
Dependent Claim
51 words
The invention as described in claim 12 in which said first and second coils are connected in series with collector electrodes of said first and second transistors, respectively, and said driving coil is connected in series from the collector electrode of said first transistor to the collector electrode of second transistor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |