US3694115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molding apparatus for making anisotropic ring-shaped magnets with zones having a preferred radial direction
Assignee: Magnetfabrik Bonn GmbH
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Filing: 1970-03-30
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Granted: 1972-09-26
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Expires: 1990-03-30
Abstract
Abstract Apparatus for the production of ring-shaped permanent magnets having radial lines of force from permanent magnet powder and a binder comprises a die holder provided with a liner of hard having high mechanical strength and/or abrasion resistance magnetic material for cooperation with a center ram and opposed end wall rams.
Inventors
- 👤 Eric Steingroever
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:11
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/008; H; H01; H01F; H01F41/00; H01F41/02; H01F41/0253; H01F41/0273; H01F41/028
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
Apparatus for the production of ring-shaped magnets having radially oriented lines of force defining a plurality of circumferentially disposed magnetic poles from permanent magnet powder and non-magnetic binder, comprising a ring-shaped die liner of magnetic material having high mechanical strength and/or resistance to wear defining the outer wall of the magnets to be produced, a die holder surrounding said die liner, means to produce a multi-pole magnetic field to magnetically saturate the die liner and having the lines of force disposed in planes perpendicular to the axis of said ring-shaped die liner, a center ram defining the inner wall of a ring-shaped magnet to be produced, and a pair of annular opposed movable ram elements to define the opposite end walls of a ring-shaped magnet to be produced.
Claim 2
Dependent Claim
128 words
Apparatus for the production of ring-shaped magnets having radially oriented lines of force defining a plurality of circumferentially disposed magnetic poles from permanent magnet powder and non-magnetic binder, comprising a ring-shaped die liner of magnetic material having high mechanical strength and/or resistance to wear defining the outer wall of the magnets to be produced, a die holder surrounding said die liner, means to produce a multi-pole magnetic field to magnetically saturate the die liner and having the lines of force disposed in planes perpendicular to the axis of said ring-shaped die liner, a center ram defining the inner wall of a ring-shaped magnet to be produced, and a pair of annular opposed movable ram elements to define the opposite end walls of a ring-shaped magnet to be produced.
Claim 3
Dependent Claim
16 words
The invention as claimed in claim 1 wherein said center ram is made of ferromagnetic material.
Claim 4
Dependent Claim
16 words
The invention as claimed in claim 1 wherein said ram elements are made of ferromagnetic material.
Claim 5
Dependent Claim
36 words
The invention as claimed in claim 1, wherein at least one of said annular rams includes an axial projection to form an indentation in a portion of an end wall of a magnet to be produced.
Claim 6
Dependent Claim
79 words
The invention as claimed in claim 1, wherein said multi-pole magnetic field is arranged to produce a pair of poles disposed diametrically on opposite sides of the axis of the ring-shaped magnet to be produced, and at least one of said annular rams includes a pair of circumferentially spaced projections to form indentations in portions of an end wall of a magnet to be produced, said projections being generally located between said pair of magnetic poles of said magnet.
References Cited (Backward Citations)
US2384215A
Cited
US2999271A
Cited
US3274303A
Cited
US3250831A
Cited
US3416191A
Cited
US3555621A
Cited
US3452121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |