US3737746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quartz crystal controlled stepper motor
Assignee: GEN TIME CORP
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Filing: 1972-04-19
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Granted: 1973-06-05
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Expires: 1992-04-19
Abstract
Abstract A battery powered self-starting stepper motor driven by pulses of alternating polarity derived from a quartz crystal oscillator via a divider circuit. The output of the quartz crystal oscillator is connected to a divider circuit which divides the high frequency output of the oscillator down to 1 Hz. The complementary outputs of the last divider stage are coupled to a pair of bistable circuits and the output of an intermediate divider stage is connected to the reset terminals of the bistable circuits to limit the pulse width or duty cycle of the pulses generated by each bistable circuit. The respective outputs of the bistable circuits are coupled to the energizing winding on the stator core of the stepper motor via a drive circuit such that the pulses from one of the bistable circuits are passed through the winding in a first direction and the pulses from the other bistable are passed through the winding in the opposite direction.
Inventors
- 👤 E Cielaszyk
- 👤 R Lundin
- 👤 F Stellwagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:27
CPC Classifications
H; H02; H02K; H02K33/00; H02K33/16; G; G04; G04C; G04C13/00; G04C13/08; G04C13/10; G04C3/00; G04C3/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
174 words
A battery operated stepper motor comprising in combination, a stator having a core and an energizing winding, said core being separated to form a generally circular air gap, the periphery of said air gap being notched to form a plurality of stator pole faces, a rotor including a pair of spaced rotor discs, each disc having a plurality of teeth spaced about the periphery thereof to form a plurality of rotor pole faces, said rotor further including a permanent magnet positioned between and secured to said rotor discs, means for limiting the rotational movement of said rotor to a predetermined arc length, a quartz crystal oscillator, means for dividing the frequency of the output of said oscillator, digital means for substantially reducing the duty cycle of the output of said dividing means, and drive means for coupling the output of said duty cycle reducing means to said stator winding to thereby generate an alternating flux field in said stator core, said alternating flux field driving said rotor with a to and fro oscillatory motion.
Claim 2
Dependent Claim
174 words
A battery operated stepper motor comprising in combination, a stator having a core and an energizing winding, said core being separated to form a generally circular air gap, the periphery of said air gap being notched to form a plurality of stator pole faces, a rotor including a pair of spaced rotor discs, each disc having a plurality of teeth spaced about the periphery thereof to form a plurality of rotor pole faces, said rotor further including a permanent magnet positioned between and secured to said rotor discs, means for limiting the rotational movement of said rotor to a predetermined arc length, a quartz crystal oscillator, means for dividing the frequency of the output of said oscillator, digital means for substantially reducing the duty cycle of the output of said dividing means, and drive means for coupling the output of said duty cycle reducing means to said stator winding to thereby generate an alternating flux field in said stator core, said alternating flux field driving said rotor with a to and fro oscillatory motion.
Claim 3
Dependent Claim
85 words
The battery operated stepper motor of claim 1 wherein said separated stator core defines at least one channel extending radially with respect to said air gap, and wherein said means for limiting the rotational movement of said rotor comprises an elongated tooth formed integral with one of said rotor discs, said tooth extending into said channel defined by said stator core so that rotational movement of said rotor is limited by said tooth making contact with the portions of said stator which define said channel.
Claim 4
Dependent Claim
66 words
The battery powered stepper motor of claim 2 wherein said elongated rotor tooth further comprises a pair of side portions proximate the end of said tooth, said side portions forming a pair of rotor pole faces, and a spacer element mounted on each side portion to prevent said rotor pole faces on said elongated tooth from contacting the portions of said stator core defining said channel.
Claim 5
Dependent Claim
53 words
The battery powered stepper motor of claim 3 wherein said rotor pole faces are biased with respect to said stator pole faces such that when said elongated tooth is in a first contact position with respect to the stator, the rotor is biased to rotate said elongated tooth to the other contact position.
Claim 6
Dependent Claim
83 words
The battery powered stepper motor of claim 4 wherein said dividing means comprises a plurality of cascaded divider stages, each divider stage having a pair of complementary output terminals, and wherein said means for reducing the duty cycle of the output of said dividing means comprises a pair of bistable circuits for receiving the complementary outputs of the last divider stage of said dividing means, said bistable circuits each being reset by the output of an intermediate divider stage of said dividing means.
Claim 7
Dependent Claim
202 words
In an electronic watch movement including a seconds hand, a minutes hand, and an hour hand and gearing means for coupling rotational movement to said hands, the improvement comprising in combination a battery operated stepper motor, a stator having a core and an energizing winding, said core being separated to form a generally circular air gap, the periphery of said air gap being notched to form a plurality of stator pole faces, a rotor including a pair of spaced rotor discs, each disc having a plurality of teeth spaced about the periphery thereof to form a plurality of rotor pole faces, said rotor further including a permanent magnet positioned between and secured to said rotor discs, means for limiting the rotational movement of said rotor to a predetermined arc length, a quartz crystal oscillator, means for dividing the frequency of the output of said oscillator, digital means for substantially reducing the duty cycle of the output of said dividing means, and drive means for coupling the output of said duty cycle reducing means to said stator winding to thereby generate an alternating flux field in said stator core, said alternating flux field driving said rotor with a to and fro oscillatory motion.
Claim 8
Dependent Claim
202 words
In an electronic watch movement including a seconds hand, a minutes hand, and an hour hand and gearing means for coupling rotational movement to said hands, the improvement comprising in combination a battery operated stepper motor, a stator having a core and an energizing winding, said core being separated to form a generally circular air gap, the periphery of said air gap being notched to form a plurality of stator pole faces, a rotor including a pair of spaced rotor discs, each disc having a plurality of teeth spaced about the periphery thereof to form a plurality of rotor pole faces, said rotor further including a permanent magnet positioned between and secured to said rotor discs, means for limiting the rotational movement of said rotor to a predetermined arc length, a quartz crystal oscillator, means for dividing the frequency of the output of said oscillator, digital means for substantially reducing the duty cycle of the output of said dividing means, and drive means for coupling the output of said duty cycle reducing means to said stator winding to thereby generate an alternating flux field in said stator core, said alternating flux field driving said rotor with a to and fro oscillatory motion.
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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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |