Patent US4700436A successfully refreshed from Google Patents.
US4700436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic fastener
Assignee: DYNAMAR CORP
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Filing: 1986-03-05
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Granted: 1987-10-20
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Expires: 2006-03-05
Abstract
Abstract A magnetic fastener comprising a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached at the first side of the magnet member, a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the permanent magnet member being a dispersion of hard magnetic powder in a matrix of synthetic resin, and the first magnetic pole plate being integrally attached to the permanent magnet member by the permanent magnet member itself. The permanent magnet member may be comprised of a molded member made by casting wherein the first magnetic pole plate is at least partly incorporated in the molded magnetic member or may be embedded therein. A hole is provided through the permanent magnet member extending between the first and second sides, and projections on the first and second pole plates extend into the hole so that the projections are magnetically attracted to each other and to the corresponding pole plate. The permanent magnet member being comprised of hard magnetic powder bound together by a synthetic resin and the first pole plate being incorporated as a part of the permanent magnet itself obviates the necessity for a protective covering or casing over the permanent magnet member and a reduction in the magnetic reluctance between the permanent magnet member and the first and second pole plates.
Inventors
- 👤 Tamao Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:11
CPC Classifications
A; A44; A44B; A44B19/00; E; E05; E05C; E05C19/00; E05C19/16; A45; A45C; A45C13/00; A45C13/10; A45C13/1069; H; H01; H01F; H01F7/00; H01F7/02; H01F7/0231; H01F7/0252; H01F7/0263; Y; Y10; Y10T; Y10T24/00; Y10T24/32; Y10T292/00; Y10T292/11
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
105 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; and said first magnetic pole plate is integrally attached to said permanent magnet member by said permanent magnet member itself.
Claim 2
Dependent Claim
105 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; and said first magnetic pole plate is integrally attached to said permanent magnet member by said permanent magnet member itself.
Claim 3
Dependent Claim
23 words
A magnetic fastener as claimed in claim 1 wherein: said first magnetic pole plate is at least partly incorporated in said magnetic member.
Claim 4
Dependent Claim
53 words
A magnetic fastener as claimed in claim 2 and further comprising: A hole through said permanent magnet member extending between the first and second sides; and projections on said first and second magnetic pole plates extending into said hole, said projections being magnetically attracted to each other and to the corresponding pole plate.
Claim 5
Dependent Claim
28 words
A magnetic fastener as claimed in claim 3 wherein: said second magnetic pole plate is attachable in direct contact with said second side of said permanent magnet member.
Claim 6
Dependent Claim
48 words
A magnetic fastener as claimed in claim 4 and further comprising: a raised edge surrounding the magnetic pole on said second side of said permanent magnet member forming a rim so that said second magnetic pole plate is located within said rim when attached to said second side.
Claim 7
Dependent Claim
46 words
A magnetic fastener as claimed in claim 4 wherein: said first magnetic pole plate is at least partly embedded in said permanent magnet member so that a thin layer of the permanent magnet member is provided between said first side and said first magnetic pole plate.
Claim 8
Dependent Claim
50 words
A magnetic fastener as claimed in claim 4 wherein: said first pole plate has a chamfered peripheral edge having a chamfered surface facing substantially outwardly of said first side; and a portion of said permanent magnet member at a peripheral edge thereof at said first side overlies said chamfered surface.
Claim 9
Dependent Claim
53 words
A magnetic fastener as claimed in claim 1 and further comprising: a hole through said permanent magnet member extending between the first and second sides; and projections on said first and second magnetic pole plates extending into said hole, said projections being magnetically attracted to each other and to the corresponding pole plate.
Claim 10
Dependent Claim
28 words
A magnetic fastener as claimed in claim 1 wherein: said second magnetic pole plate is attachable in direct contact with said second side of said permanent magnet member.
Claim 11
Dependent Claim
48 words
A magnetic fastener as claimed in claim 1 and further comprising: a raised edge surrounding the magnetic pole on said second side of said permanent magnet member forming a rim so that said second magnetic pole plate is located within said rim when attached to said second side.
Claim 12
Dependent Claim
46 words
A magnetic fastener as claimed in claim 1 wherein: said first magnetic pole plate is at least partly embedded in said permanent magnet member so that a thin layer of the permanent magnet member is provided between said first side and said first magnetic pole plate.
Claim 13
Dependent Claim
50 words
A magnetic fastener as claimed in claim 1 wherein: said first pole plate has a chamfered peripheral edge having a chamfered surface facing substantially outwardly of said first side; and a portion of said permanent magnet member at a peripheral edge thereof at said first side overlies said chamfered surface.
Claim 14
Dependent Claim
130 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member; the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole plate is integrally attached to said permanent magnet member by said permanent magnet member itself; and a magnetic shielding plate attached to the second side of said permanent magnet member for attracting magnetic flux at the pole adjacent said second side.
Claim 15
Dependent Claim
130 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member; the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole plate is integrally attached to said permanent magnet member by said permanent magnet member itself; and a magnetic shielding plate attached to the second side of said permanent magnet member for attracting magnetic flux at the pole adjacent said second side.
Claim 16
Dependent Claim
48 words
A magnetic fastener as claimed in claim 13 and further comprising: a raised edge surrounding the magnetic pole on said second side of said permanent magnet member forming a rim so that said second magnetic pole plate is located within said rim when attached to said second side.
Claim 17
Dependent Claim
39 words
A magnetic fastener as claimed in claim 14 wherein: said magnetic shielding plate is attached to said second side by said rim; and said rim projects outwardly from said second side a greater distance than said magnetic shielding plate.
Claim 18
Dependent Claim
116 words
A magnetic fastener as claimed in claim 14 wherein: said magnetic shielding plate is attached to said second side by side rim; said rim projects outwardly from said second side a distance greater than said magnetic shielding plate; said first magnetic pole plate is at least partly incorporated in said magnetic member; said second magnetic pole plate is attachable in direct contact with said second side of said permanent magnet member; and further comprising a hole through said permanent magnet member extending between the first and second sides; and projections on said first and second magnetic pole plates extending into said hole, said projections being magnetically attracted to each other and to the corresponding pole plate.
Claim 19
Dependent Claim
153 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnetic member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole is integrally attached to said permanent magnet member by said permanent magnet member itself; and further comprising a magnetic shielding plate embedded in said permanent magnet member adjacent said second side thereof for attracting magnetic flux at the pole at said second side; and a thin layer formed by a portion of the permanent magnet member between said second side and said shielding plate.
Claim 20
Dependent Claim
153 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnetic member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole is integrally attached to said permanent magnet member by said permanent magnet member itself; and further comprising a magnetic shielding plate embedded in said permanent magnet member adjacent said second side thereof for attracting magnetic flux at the pole at said second side; and a thin layer formed by a portion of the permanent magnet member between said second side and said shielding plate.
Claim 21
Dependent Claim
48 words
A magnetic fastener as claimed in claim 17 and further comprising: a raised edge surrounding the magnetic pole on said second side of said permanent magnet member forming a rim so that said second magnetic pole plate is located within said rim when attached to said second side.
Claim 22
Dependent Claim
25 words
A magnetic fastener as claimed in claim 18 wherein: said rim projects outwardly from said second side a greater distance than said magnetic shielding plate.
Claim 23
Dependent Claim
210 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole plate is at least partly incorporated in said permanent magnetic member; said second magnetic pole plate is attachable in direct contact with said second side of said permanent magnet member; and further comprising a magnetic shielding plate embedded in said permanent magnet member adjacent said second side thereof for attracting magnetic flux at the pole at said second side; a thin layer formed by a portion of the permanent magnet member between said second side and said shielding plate; a hole through said permanent magnet member extending between the first and second sides; and projections on said first and second magnetic pole plates extending into said hole, said projections being magnetically attracted to each other and to the corresponding pole plate.
Claim 24
Dependent Claim
210 words
In a magnetic fastener including a permanent magnet member having first and second sides of opposite polarity, a first magnetic pole plate attached against the first side of the magnet member and a second magnetic pole plate removably attachable on the second side of the magnet member, the pole plates being magnetically attracted to the magnet member and to each other through the magnet member, the improvement wherein: said permanent magnet member comprises a dispersion of hard magnetic powder in a matrix of synthetic resin; said first magnetic pole plate is at least partly incorporated in said permanent magnetic member; said second magnetic pole plate is attachable in direct contact with said second side of said permanent magnet member; and further comprising a magnetic shielding plate embedded in said permanent magnet member adjacent said second side thereof for attracting magnetic flux at the pole at said second side; a thin layer formed by a portion of the permanent magnet member between said second side and said shielding plate; a hole through said permanent magnet member extending between the first and second sides; and projections on said first and second magnetic pole plates extending into said hole, said projections being magnetically attracted to each other and to the corresponding pole plate.
References Cited (Backward Citations)
DE1068149B
Cited
US2340781A
Cited
US2615227A
Cited
US2623256A
Cited
US2726110A
Cited
DE1127509B
Cited
CH374845A
Cited
FR1268582A
Cited
US3159372A
Cited
US3100663A
Cited
US3192747A
Cited
US3324521A
Cited
US3897288A
Cited
US4021891B1
Cited
US4021891A
Cited
US4021891B2
Cited
US4033013A
Cited
US4200852A
Cited
US4390458A
Cited
US4438164A
Cited
US4453294A
Cited
US4453294B1
Cited
US4453294B2
Cited
US4455719A
Cited
US4458395A
Cited
US4480361A
Cited
US4556611A
Cited
US4593736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |