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US 5,019,796 AGranted
Bar magnet for construction of a magnetic roller core
AssigneeEastman Kodak Company
InventorsJames K. Lee, Donald J. McJury, Michael A. Pickup, Kelly S. Robinson
Life of this patent
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Abstract
An improved bar magnet and method of construction, and an improved magnetic core comprising an assembly of such magnets, for use in a processing station of an electrostatographic printing machine. The improved bar magnet is formed of permanent magnet material having magnetic domains therein that are magnetized along epicycloidal curve segments. The external magnetic flux density is improved over that of a conventionally-magnetized magnet. An injection mold for inducing the particular epicycloidal alignment of magnetic domains in the improved bar magnet is provided.
Claims41
A magnet for a magnetic core, the magnet comprising:
- a body of hard magnetic material having magnetic domains therein;
- and
- a first magnetic pole face and second and third generally mutually opposing magnetic pole faces, the first pole face being of a first polarity and located generally transverse to said second and third pole faces, the second and third pole faces being of a polarity opposite to that of the first pole face, and the domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces.
A magnet for a magnetic core, the magnet comprising:
- a body of hard magnetic material having opposing first and fourth surfaces and mutually opposing second and third surfaces;
- the hard magnetic material having magnetic domains aligned to create a magnetic pole face of a first polarity associated with the first surface and pole faces of an opposite polarity associated with the second and third surfaces;
- and
- the domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces.
1 more element
A magnet for a magnetic core, the magnet comprising:
- a body of hard magnetic material having magnetic domains therein, and first, second, and third magnetic pole faces, the first pole face being located adjacent to and contiguous with the second and third pole faces;
- and
- the second and third pole faces having a polarity that is the opposite of the first pole face and the domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces;
- wherein the effect of the location of the second and third pole faces is an increase in the external magnetic field strength at the first pole face.
1 more element
A magnetic core for use in a magnetic roller, comprising:
- a support;
- and
- a plurality of magnets mounted peripherally around the support,
- each magnet having a body of hard magnetic material having magnetic domains therein, and a first magnetic pole face and second and third generally mutually opposing magnetic pole faces, the first pole face being of a first polarity and located generally transverse to said second and third pole faces, the second and third pole faces being of a polarity opposite to that of the first pole face, and the domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces;
- wherein each magnet is positioned on the support between at least two adjoining magnets, the first pole faces of the magnets being circumferentially positioned with alternating polarity, and the second and third pole faces of each magnet being oriented to like faces of opposite polarity in the adjoining magnets.
2 more elements
A method of producing a magnet for a magnetic core, comprising the steps of:
- forming a body of hard magnetic material having having magnetic domains therein and having a first surface and second and third generally mutually opposing surfaces, the first surface being located generally transverse to the second and third surfaces;
- positioning, with respect to the first, second, and third surfaces, magnetizing means operable for inducing magnetizing field lines along generally diverging curved paths between the first surface and the second and third surfaces;
- and
- activating the magnetizing means to magnetize the domains along the paths and to induce first, second, and third remanent magnetic pole faces respectively at the first, second, and third surfaces, the first pole face being of a first polarity and the second and third pole faces being of a polarity opposite to that of the first pole face.
1 more element
A method of producing a multiple bar magnetic core, the core having a circumferential surface, comprising the steps of:
- providing a plurality of bar magnets, the provision of each magnet comprising the steps of:
- (a) forming a body of hard magnetic material having magnetic domains therein, and
- (b) magnetizing first and second pluralities of the magnetic domains to provide a first magnetic pole face and second and third generally mutually opposing magnetic pole faces, the first pole face being of a first polarity and located generally transverse to said second and third pole faces, the second and third pole faces being of a polarity opposite to that of the first pole face, and the first and second pluralities of domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces;
- orienting the first magnetic pole face of each bar magnet at the core circumferential surface;
- orienting the second and third magnetic pole faces of each magnet respectively adjacent to the second and third magnetic pole faces of adjacent bar magnets;
- and
- joining the oriented magnets together to form a rigid core.
4 more elements
A magnet for a magnetic core, the magnet made by the process of:
- forming a body of hard magnetic material having magnetic domains therein;
- and
- magnetizing first and second pluralities of the magnetic domains to provide a first magnetic pole face and second and third generally mutually opposing magnetic pole faces, the first pole face being of a first polarity and located generally transverse to said second and third pole faces, the second and third pole faces being of a polarity opposite to that of the first pole face, and the first and second pluralities of domains being aligned along generally diverging curved paths between the first pole face and the second and third pole faces.
A magnet for a magnetic core, the magnet made by the process of:
- forming a body of hard magnetic material having having magnetic domains therein and having a first surface and second and third generally mutually opposing surfaces, the first surface being located generally transverse to the second and third surfaces;
- positioning, with respect to the first, second, and third surfaces, magnetizing means operable for inducing magnetizing field lines along generally diverging curved paths between the first surface and the second and third surfaces;
- and
- activating the magnetizing means to magnetize the domains along the paths and to induce first, second, and third remanent magnetic pole faces respectively at the first, second, and third surfaces, the first pole face being of a first polarity and the second and third pole faces being of a polarity opposite to that of the first pole face.
1 more element
Dependencies are inferred from the claim text.