Patent US3946259A successfully refreshed from Google Patents.
US3946259A
Expired / Lapsed
US
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Electric stepping motors and remote registers
Assignee: Sangamo Weston Ltd
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Filing: 1973-09-14
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Granted: 1976-03-23
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Expires: 1993-09-14
Abstract
Abstract A stepping motor for use in a remote register, such as is used for the remote reading of electricity meters, is arranged to be advanced by current pulses of known constant polarity. The motor includes magnetic biasing means which effect further rotation of the rotor of the stepping motor in the same given direction each time that an input current pulse ends. The motor can therefore be controlled by a simple ON/OFF switch in the electricity meter circuit with a rectifier being provided in the remote register. The magnetic biasing means may consist of one or more cylindrical magnets co-axial with the rotor, or a straight or arcuate bar magnet adjacent to the periphery of the rotor.
Inventors
- 👤 Maurice Graham McBride
- 👤 Bernard Herbert Leslie Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:30
CPC Classifications
G; G06; G06M; G06M1/00; G06M1/08; G06M1/10; G06M1/102; G06M1/107; H; H02; H02K; H02K37/00; H02K37/10; H02K37/12; H02K37/14; H02K37/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
196 words
An electric stepping motor comprising a permanently magnetised rotor having peripheral magnetic poles, means mounting said rotor for rotation about an axis of rotation, a stationary magnetic circuit comprising a pair of stator pole members each having at least one polar surface positioned adjacent to the periphery of the rotor, an electromagnet winding associated with a part of the magnetic circuit to produce, when energised, opposite magnetic polarities in the respective stator pole members, and stationary magnetic biasing means fixedly mounted on frame means adjacent to said rotor, the magnetic flux in the magnetic circuit and through the rotor by way of the polar surfaces being sufficient as to produce and output rotary movement of said rotor through a first predetermined angle in a given direction in response to an input energizing current to said winding, and the magnetic flux due to said biasing means being sufficient as to produce a rotary movement of the rotor through a second predetermined angle in the same direction as the first-mentioned direction in response to de-energisation of said winding but being insufficient to prevent the rotation of the rotor through said first predetermined angle when said winding is energized.
Claim 2
Dependent Claim
196 words
An electric stepping motor comprising a permanently magnetised rotor having peripheral magnetic poles, means mounting said rotor for rotation about an axis of rotation, a stationary magnetic circuit comprising a pair of stator pole members each having at least one polar surface positioned adjacent to the periphery of the rotor, an electromagnet winding associated with a part of the magnetic circuit to produce, when energised, opposite magnetic polarities in the respective stator pole members, and stationary magnetic biasing means fixedly mounted on frame means adjacent to said rotor, the magnetic flux in the magnetic circuit and through the rotor by way of the polar surfaces being sufficient as to produce and output rotary movement of said rotor through a first predetermined angle in a given direction in response to an input energizing current to said winding, and the magnetic flux due to said biasing means being sufficient as to produce a rotary movement of the rotor through a second predetermined angle in the same direction as the first-mentioned direction in response to de-energisation of said winding but being insufficient to prevent the rotation of the rotor through said first predetermined angle when said winding is energized.
Claim 3
Dependent Claim
59 words
An electric stepping motor according to claim 1, in which said magnetic biasing means comprises at least one cylindrical magnet mounted on said frame means co-axially with respect to said axis of rotation and magnetised to provide a north-seeking pole at one region of its periphery and a complementary south-seeking pole at a diametrically opposite region of its periphery.
Claim 4
Dependent Claim
46 words
An electric stepping motor according to claim 1, in which said magnetic biasing means comprises a linear bar magnet having one end adjacent to the periphery of said rotor and having its longitudinal axis perpendicular to and passing through said axis of rotation of the rotor.
Claim 5
Dependent Claim
64 words
An electric stepping motor according to claim 1, in which said magnetic biasing means comprises an arcuate bar magnet positioned adjacent to the periphery of a portion of said rotor and concentric with respect to said axis of rotation, the angle subtended by said magnet at the centre of the rotor being equal to the angular spacing between two rotor poles of opposite polarity.
Claim 6
Dependent Claim
147 words
An electric stepping motor according to claim 1, in which said rotor comprises a cylindrical magnet magnetised diametrically to provide a single north-seeking pole at one peripheral region and a single complementary south-seeking pole at a diametrically opposite peripheral region, and in which said stationary magnetic circuit comprises a pair of main stator poles each having a flat main polar surface, which main polar surfaces are parallel to each other on diametrically opposite sides of the periphery of the rotor magnet, and at least one subsidiary stator pole having a flat subsidiary polar surface lying at an angle of 90° to said main polar surfaces and adjacent to the periphery of the rotor magnet, energisation of said winding producing opposite magnetic polarities in said main stator poles and the same magnetic polarity in said subsidiary stator pole as in a given one of said main stator poles.
Claim 7
Dependent Claim
151 words
An electric stepping motor according to claim 3, in which said rotor comprises a cylindrical magnet magnetised to provide two diametrically opposed north-seeking poles and two diametrically opposed south-seeking poles with adjacent poles spaced 90° apart, and in which said stationary magnetic circuit comprises a first strip of ferromagnetic material bent at 45° towards one end to form a first main stator pole and a first subsidiary stator pole at 45° to the main pole and connected towards its other end to one end of a magnetic core of said winding, and a second strip of ferromagnetic material bent at right-angles near its mid-region and bent again towards one end at 45° to form a second main stator pole and a second subsidiary stator pole at 45° to the main pole, the other end of said second strip being connected to the other end of said magnetic core of the winding.
Claim 8
Dependent Claim
152 words
An electric stepping motor according to claim 4, in which said rotor comprises a cylindrical magnet magnetised to provide two diametrically opposed north-seeking poles and two diametrically opposed south-seeking poles with adjacent poles spaced 90° apart, and in which said stationary magnetic circuit comprises a first strip of ferromagnetic material bent at 45° towards one end to form a first main stator pole and a first subsidiary stator pole at 45° to the main stator pole and connected towards its other end to one end of a magnetic core of said winding, and a second strip of ferromagnetic material bent at right-angles near its mid-region and bent again towards one end at 45° to form a second main stator pole and a second subsidiary stator pole at 45° to the main pole, the other end of said second strip being connected to the other end of said magnetic core of the winding.
Claim 9
Dependent Claim
42 words
An electric stepping motor according to claim 1, in which the poles of said magnetic biasing means are angularly offset relative to the poles of the rotor when said winding is de-energised to ensure rotation of the rotor in said given direction.
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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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |