US3879624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary solenoids in brush-application gear
Assignee: GEC AEROSPACE Ltd
•
Filing: 1973-04-24
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Granted: 1975-04-22
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Expires: 1993-04-24
Abstract
Abstract In order to retain the rotary brush-application solenoid of a starter-brush lifting mechanism in brush-application position, even under considerable reduction of the solenoid-energising voltage such as may be due to heavy starting current, the rotor is equipped with retention poles which are moved by the solenoid applying rotation into contact with the end faces of the inner and outer stator poles between which the rotor poles enter so as to form magnet armatures which retain the rotor, by strong magnetic forces, against reverse rotation. The solenoid energising voltage at which release takes place is determined by the thickness of shims interposed between the leading end faces of each retention pole and the said end of the stator poles. Conveniently the shims are clamped between each retention pole end of the rotor pole to which the retention pole is attached.
Inventors
- 👤 Frederick Raymond Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:30
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/42; H01F; H01F7/00; H01F7/06; H01F7/08; H02; H02K; H02K5/00; H02K5/04; H02K5/14; H02K5/143
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
290 words
A device for applying brushes to the commutator of an electrical starter motor, which comprises brush-lifting spring means which normally maintain the brushes clear of the commutator, and a rotary solenoid having a stator and a rotor member rotatable relative thereto about an axis of rotation and operative, when the solenoid is energised, to cause application of the brushes to the commutator against the action of said spring means, said rotary solenoid, said stator including a set of outer pole pieces spaced circumferentially about said axis, a set of inner pole pieces, similarly spaced circumferentially about said axis and arranged to respectively face the outer pole pieces across a radial gap, a magnetising winding arranged to produce a magnetic field by which all the inner stator pole pieces and all the outer stator pole pieces are magnetised with respectively opposite polarities, and said rotor member having a set of magnetisable pole pieces which are spaced circumferentially about said axis at an angular pitch corresponding to that of the stator pole pieces so that rotation of the rotor from a normal position to an operative position will cause each rotor pole piece to enter the gap between an inner stator pole piece and the corresponding outer stator pole piece, said rotor member being equipped with auxiliary pole pieces each of which extends radially from the trailing end of one of said rotor pole pieces beyond both limits of the gap between the inner and outer stator pole pieces to face the ends of an inner and an outer stator pole piece so that at the completion of rotor movement to said operative position the auxiliary pole piece reaches a position of near-contact with the said ends of the stator pole pieces.
Claim 2
Independent Claim
290 words
A device for applying brushes to the commutator of an electrical starter motor, which comprises brush-lifting spring means which normally maintain the brushes clear of the commutator, and a rotary solenoid having a stator and a rotor member rotatable relative thereto about an axis of rotation and operative, when the solenoid is energised, to cause application of the brushes to the commutator against the action of said spring means, said rotary solenoid, said stator including a set of outer pole pieces spaced circumferentially about said axis, a set of inner pole pieces, similarly spaced circumferentially about said axis and arranged to respectively face the outer pole pieces across a radial gap, a magnetising winding arranged to produce a magnetic field by which all the inner stator pole pieces and all the outer stator pole pieces are magnetised with respectively opposite polarities, and said rotor member having a set of magnetisable pole pieces which are spaced circumferentially about said axis at an angular pitch corresponding to that of the stator pole pieces so that rotation of the rotor from a normal position to an operative position will cause each rotor pole piece to enter the gap between an inner stator pole piece and the corresponding outer stator pole piece, said rotor member being equipped with auxiliary pole pieces each of which extends radially from the trailing end of one of said rotor pole pieces beyond both limits of the gap between the inner and outer stator pole pieces to face the ends of an inner and an outer stator pole piece so that at the completion of rotor movement to said operative position the auxiliary pole piece reaches a position of near-contact with the said ends of the stator pole pieces.
Claim 3
Independent Claim
290 words
A device for applying brushes to the commutator of an electrical starter motor, which comprises brush-lifting spring means which normally maintain the brushes clear of the commutator, and a rotary solenoid having a stator and a rotor member rotatable relative thereto about an axis of rotation and operative, when the solenoid is energised, to cause application of the brushes to the commutator against the action of said spring means, said rotary solenoid, said stator including a set of outer pole pieces spaced circumferentially about said axis, a set of inner pole pieces, similarly spaced circumferentially about said axis and arranged to respectively face the outer pole pieces across a radial gap, a magnetising winding arranged to produce a magnetic field by which all the inner stator pole pieces and all the outer stator pole pieces are magnetised with respectively opposite polarities, and said rotor member having a set of magnetisable pole pieces which are spaced circumferentially about said axis at an angular pitch corresponding to that of the stator pole pieces so that rotation of the rotor from a normal position to an operative position will cause each rotor pole piece to enter the gap between an inner stator pole piece and the corresponding outer stator pole piece, said rotor member being equipped with auxiliary pole pieces each of which extends radially from the trailing end of one of said rotor pole pieces beyond both limits of the gap between the inner and outer stator pole pieces to face the ends of an inner and an outer stator pole piece so that at the completion of rotor movement to said operative position the auxiliary pole piece reaches a position of near-contact with the said ends of the stator pole pieces.
Claim 4
Independent Claim
290 words
A device for applying brushes to the commutator of an electrical starter motor, which comprises brush-lifting spring means which normally maintain the brushes clear of the commutator, and a rotary solenoid having a stator and a rotor member rotatable relative thereto about an axis of rotation and operative, when the solenoid is energised, to cause application of the brushes to the commutator against the action of said spring means, said rotary solenoid, said stator including a set of outer pole pieces spaced circumferentially about said axis, a set of inner pole pieces, similarly spaced circumferentially about said axis and arranged to respectively face the outer pole pieces across a radial gap, a magnetising winding arranged to produce a magnetic field by which all the inner stator pole pieces and all the outer stator pole pieces are magnetised with respectively opposite polarities, and said rotor member having a set of magnetisable pole pieces which are spaced circumferentially about said axis at an angular pitch corresponding to that of the stator pole pieces so that rotation of the rotor from a normal position to an operative position will cause each rotor pole piece to enter the gap between an inner stator pole piece and the corresponding outer stator pole piece, said rotor member being equipped with auxiliary pole pieces each of which extends radially from the trailing end of one of said rotor pole pieces beyond both limits of the gap between the inner and outer stator pole pieces to face the ends of an inner and an outer stator pole piece so that at the completion of rotor movement to said operative position the auxiliary pole piece reaches a position of near-contact with the said ends of the stator pole pieces.
Claim 5
Dependent Claim
41 words
A device as claimed in claim 1, wherein movement-limiting means are provided which terminate movement of the auxiliary pole pieces when a residual gap in the ferromagnetic circuit is left between each auxiliary pole piece and the co-operating stator-pole end surfaces.
Claim 6
Dependent Claim
26 words
A device as claimed in claim 2, wherein the movement-limiting means include a thin non-magnetic lining on one of the mutual facing surfaces defining said gap.
Claim 7
Dependent Claim
31 words
A device as claimed in claim 3, wherein the non-magnetic lining comprises a shim clamped between an auxiliary pole and the rotor pole piece from which the auxiliary pole piece extends.
References Cited (Backward Citations)
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US2780949A
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US2753477A
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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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |