US3689855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit protector
Assignee: Panasonic Electric Works Co Ltd
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Filing: 1971-04-22
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Granted: 1972-09-05
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Expires: 1991-04-22
Abstract
Abstract A circuit protector including an electromagnetic device, said device comprising a coil through which circuit current flows and wound on a coil bobbin, a cylinder provided at the center of said bobbin, an oil-dash type plunger provided within said cylinder movably against a compression force of a spring arranged between a cylinder head and the plunger, a yoke integrally connected to said cylinder and the bobbin, and an armature mounted to an end of said yoke in a manner capable of being attracted to the plunger head, said bobbin is provided with a magnetic leakage in the vicinity to the cylinder head.
Inventors
- 👤 Isami Setone
- 👤 Akira Yoshino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:52
CPC Classifications
H; H01; H01H; H01H71/00; H01H71/10; H01H71/12; H01H71/24; H01H71/34; H01H71/345
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
270 words
An electromagnetic circuit protector comprising the combination of an armature mounted for pivotal movement between first and second positions for Opening a pair of electrical contacts to protect an electrical circuit, a magnetizable pole member located at said second position, a magnetizable plunger mounted for reciprocating movement in a non-magnetizable cylinder leading to said pole member, biasing means urging said plunger away from said pole member, a magnetizable yoke having one end located closely adjacent said plunger and a second end extending toward said armature and said pole member, a coil disposed around said cylinder for advancing said plunger toward said pole member against the urging of said biasing means when the coil is energized for a predetermined time interval, thereby attracting said armature to said pole member due to a first magnetic circuit formed by said yoke, plunger, pole member and armature, and magnetizable short circuiting means contacting said yoke and extending to a position proximate to said pole member and lying in substantially the same plane as said pole member in the direction transverse to the direction of movement of said plunger so that the short circuiting means is substantially as far from said plunger as said pole member, said short circuiting means cooperating with said pole member, yoke and plunger to form a second magnetic circuit for short circuiting a part of the magnetic flux from said first magnetic circuit when said plunger is not engaging said pole member and thereby preventing attraction of said armature to said pole member when said coil is energized for only a short time interval less than said predetermined time interval.
Claim 2
Dependent Claim
270 words
An electromagnetic circuit protector comprising the combination of an armature mounted for pivotal movement between first and second positions for Opening a pair of electrical contacts to protect an electrical circuit, a magnetizable pole member located at said second position, a magnetizable plunger mounted for reciprocating movement in a non-magnetizable cylinder leading to said pole member, biasing means urging said plunger away from said pole member, a magnetizable yoke having one end located closely adjacent said plunger and a second end extending toward said armature and said pole member, a coil disposed around said cylinder for advancing said plunger toward said pole member against the urging of said biasing means when the coil is energized for a predetermined time interval, thereby attracting said armature to said pole member due to a first magnetic circuit formed by said yoke, plunger, pole member and armature, and magnetizable short circuiting means contacting said yoke and extending to a position proximate to said pole member and lying in substantially the same plane as said pole member in the direction transverse to the direction of movement of said plunger so that the short circuiting means is substantially as far from said plunger as said pole member, said short circuiting means cooperating with said pole member, yoke and plunger to form a second magnetic circuit for short circuiting a part of the magnetic flux from said first magnetic circuit when said plunger is not engaging said pole member and thereby preventing attraction of said armature to said pole member when said coil is energized for only a short time interval less than said predetermined time interval.
Claim 3
Dependent Claim
37 words
The circuit protector according to claim 1 wherein said coil is wound on a flanged bobbin and said short circuiting means is disposed at both sides of the pole member in a flange of the coil bobbin.
Claim 4
Dependent Claim
21 words
The circuit protector according to claim 1 wherein said pole member is positioned between the armature and the short circuiting means.
Claim 5
Dependent Claim
19 words
The circuit protector according to claim 1 wherein said yoke and armature are formed in an integral body member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |