US3976902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic wedge and the process of making said wedge
Assignee: Westinghouse Electric Corp
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Filing: 1972-01-21
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Granted: 1976-08-24
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Expires: 1992-01-21
Abstract
Abstract A magnetic wedge is made by preparing a composition of a thermosetting resin system and magnetizable particles, placing the composition in a mold, vibrating the mold at least until air bubbles are no longer evolved from the composition, curing the composition, and fabricating the lower portion of the cured composition into the shape desired for the wedge. The vibration removes air and compacts the particles which results in a wedge having overall superior physical and magnetic properties.
Inventors
- 👤 Leonard B. Simmonds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:56
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/46; H02K3/48; H02K3/487; H02K3/493; H02K15/00; H02K15/13
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
108 words
A method of making a magnetic wedge comprising: A. preparing a composition which comprises magnetizable particles and a thermosetting resin system having a viscosity of less than about 300 cps; B. placing said composition in a mold; C. vibrating said mold at least until air bubbles are no longer evolved from said composition to settle said magnetizable particles substantially into the lower portion of said mold, leaving the upper portion with substantially fewer magnetizable particles than the lower portion; D. curing said composition; E. removing the upper portion of said cured composition; and F. fabricating the lower portion of said cured composition into the shape of a wedge.
Claim 2
Independent Claim
108 words
A method of making a magnetic wedge comprising: A. preparing a composition which comprises magnetizable particles and a thermosetting resin system having a viscosity of less than about 300 cps; B. placing said composition in a mold; C. vibrating said mold at least until air bubbles are no longer evolved from said composition to settle said magnetizable particles substantially into the lower portion of said mold, leaving the upper portion with substantially fewer magnetizable particles than the lower portion; D. curing said composition; E. removing the upper portion of said cured composition; and F. fabricating the lower portion of said cured composition into the shape of a wedge.
Claim 3
Dependent Claim
24 words
A method of claim 1 wherein said thermosetting resin system comprises a resin selected from the group consisting of epoxy resins and polyester resins.
Claim 4
Dependent Claim
15 words
A method according to claim 1 wherein said thermosetting resin system comprises an epoxy resin.
Claim 5
Dependent Claim
18 words
A method according to claim 3 wherein said composition includes about 0.5 to about 1.5% of a flexibilizer.
Claim 6
Dependent Claim
12 words
A method according to claim 4 wherein said flexibilizer is polypropylene glycol.
Claim 7
Dependent Claim
11 words
A method according to claim 1 wherein said particles are iron.
Claim 8
Dependent Claim
23 words
A method according to claim 6 wherein said particles are elongated and have a length to diameter ratio of at least about 50.
Claim 9
Dependent Claim
20 words
A method according to claim 7 wherein said particles have a length to diameter ratio of at least about 250.
Claim 10
Dependent Claim
27 words
A method according to claim 7 wherein said vibrating is done in a magnetic field, the poles of said field being at the ends of said wedge.
Claim 11
Dependent Claim
21 words
A method according to claim 1 wherein said upper portion is less than the upper two fifths of said cured composition.
Claim 12
Dependent Claim
18 words
A magnetic wedge made according to the method of claim 1 wherein said magnetizable particles are a powder.
Claim 13
Dependent Claim
22 words
A method according to claim 1 wherein said particles are of a mixture of sizes between about 0.001 and about 0.1 mm.
Claim 14
Dependent Claim
35 words
A method according to claim 1 wherein said thermosetting resin is a resin which, when cured, has a deflection temperature of at least 150°C and a flexural strength of at least 10,000 psi at 25°C.
Claim 15
Dependent Claim
14 words
A method according to claim 1 wherein said composition is prepared under a vacuum.
Claim 16
Dependent Claim
11 words
A method according to claim 1 wherein said mold is horizontal.
Claim 17
Dependent Claim
30 words
A method according to claim 1 wherein said vibrating is at a frequency of about 2 to about 60 cycles/second and an amplitude of about 3 to about 6 mils.
Claim 18
Dependent Claim
16 words
A method according to claim 9 wherein said magnetic field is at least about 100 gauss.
Claim 19
Dependent Claim
26 words
A magnetic wedge according to claim 11 wherein said thermosetting resin system comprises a resin selected from the group consisting of epoxy resins and polyester resins.
Claim 20
Dependent Claim
16 words
A magnetic wedge according to claim 18 wherein said thermosetting resin system comprises an epoxy resin.
Claim 21
Dependent Claim
36 words
A magnetic wedge according to claim 11 wherein said thermosetting resin is a resin which, when cured, has a deflection temperature of at least 150°C and a flexural strength of at least 10,000 psi at 25°C.
Claim 22
Dependent Claim
27 words
A magnetic wedge according to claim 11 which contains about 65 to 70% by volume magnetizable particles and about 30 to 35% by volume thermosetting resin system.
Claim 23
Dependent Claim
23 words
A magnetic wedge according to claim 11, wherein said particles are iron and they constitute 80 to 90% by weight of said wedge.
Claim 24
Dependent Claim
30 words
A method according to claim 1, wherein said composition comprises about 75 to about 85% of said magnetizable particles and about 15 to about 25% of said thermosetting resin system.
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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) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |