US3973154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motors
Assignee: National Research Development Corp UK
•
Filing: 1974-12-30
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Granted: 1976-08-03
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Expires: 1994-12-30
Abstract
Abstract A two-speed, single-phase a.c., shaded-pole, induction motor with pole-changing, in ratio other than 2:1, by pole-amplitude modulation. The motor has stator and squirrel-cage rotor elements. The stator is made with an even number of salient poles, arranged as an even number of pole-groups, wound with at least one less number of coils than poles. Pole-changing is by reversal of the coils of consecutive pole-groups.
Inventors
- 👤 Alexander Richard William Broadway
- 👤 William Fong
- 👤 Gordon Hindle Rawcliffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:55
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/02; H02K17/04; H02K17/06; H02K17/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
74 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles, said stator having a stator winding comprising a number of coils less, by an even number, than the lower of said alternative pole-numbers, pole-changing being effected by reversal, in current-carrying sense, of one half the number of said coils.
Claim 2
Dependent Claim
74 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles, said stator having a stator winding comprising a number of coils less, by an even number, than the lower of said alternative pole-numbers, pole-changing being effected by reversal, in current-carrying sense, of one half the number of said coils.
Claim 3
Dependent Claim
23 words
A two-speed, single-phase alternating current, shaded-pole, induction motor as claimed in claim 1, in which the alternative running pole-numbers are four-poles and six-poles.
Claim 4
Dependent Claim
49 words
A two-speed, single-phase alternating current, shaded-pole, induction motor as claimed in claim 2, in which said stator is formed with four equally spaced-apart salient poles, defining two opposing pairs of poles, having one coil wound on each pole of one pair only of said two opposing pairs of poles.
Claim 5
Dependent Claim
35 words
A two-speed, single-phase alternating current, shaded-pole, induction motor as claimed in claim 1, in which said even number of stator salient poles are arranged as opposing pairs of poles unequally spaced-apart around the said stator.
Claim 6
Dependent Claim
108 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles comprising an even number of pole-groups, each pole-group having stator windings, comprising a number of coils less, by at least one, than the number of poles, pole-changing being effected by reversal, in current-carrying sense, of the said coils of consecutive pole groups, for providing alternative pole-numbers of six-poles and eight-poles, having the stator formed with six equally spaced-apart salient poles and having one coil wound on each of an opposing pair of poles.
Claim 7
Dependent Claim
108 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles comprising an even number of pole-groups, each pole-group having stator windings, comprising a number of coils less, by at least one, than the number of poles, pole-changing being effected by reversal, in current-carrying sense, of the said coils of consecutive pole groups, for providing alternative pole-numbers of six-poles and eight-poles, having the stator formed with six equally spaced-apart salient poles and having one coil wound on each of an opposing pair of poles.
Claim 8
Dependent Claim
108 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles comprising an even number of pole-groups, each pole group having stator windings comprising a number of coils less, by at least one, than the number of poles, pole-changing being effected by reversal, in current-carrying sense, of the said coils of consecutive pole groups, for providing pole-numbers of six-poles and eight-poles, having the stator formed with six equally spaced-apart salient poles and having one coil wound on each of two pairs of opposing poles.
Claim 9
Dependent Claim
108 words
A two-speed, single-phase alternating current, shaded-pole, induction motor of the pole-amplitude modulation pole-changing type, providing alternative running pole-numbers in a ratio other than 2:1, including a stator formed with an even number of salient poles comprising an even number of pole-groups, each pole group having stator windings comprising a number of coils less, by at least one, than the number of poles, pole-changing being effected by reversal, in current-carrying sense, of the said coils of consecutive pole groups, for providing pole-numbers of six-poles and eight-poles, having the stator formed with six equally spaced-apart salient poles and having one coil wound on each of two pairs of opposing poles.
References Cited (Backward Citations)
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US3295034A
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US3588649A
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US3619748A
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US3826960A
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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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |