US3970978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnet
Assignee: Telemecanique SA
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Filing: 1975-01-03
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Granted: 1976-07-20
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Expires: 1995-01-03
Abstract
Abstract The object of the present invention is a direct current-operated electromagnet. The branch of the armature which penetrates the coil body cooperates with a fixed core branch in three distinct successive modes due to the action of different air gaps. It can advantageously be used on relays for automatic equipment or on small contactors whose number of contacts is variable and/or subject to time lags.
Inventors
- 👤 Michel Langree
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:18
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/14; H01F7/13; H01H; H01H50/00; H01H50/16; H01H50/18; H01H50/20; H01H50/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
262 words
An electromagnet constituted by (i) a coil the inner zone of which has a certain axial length, and (ii) a magnetic structure, said magnetic structure comprising (a) a fixed core in the form of a "U" having a base joining a first fixed arm placed externally of the coil, and a second fixed arm having a convex external surface disposed over substantially the whole of its length, in the interior of the coil, and (b) a movable armature in the form of a "U" having a first movable arm of which one end mounted on a pivot is associated with the first fixed arm by a small air gap and a second movable arm having a first internal curved surface which is spaced by a first variable air gap from the external curved surface of the second fixed arm, and of which the end is provided with a pole surface which is transverse with respect to said first variable air gap and which is spaced by a second variable air gap from a transverse fixed surface on an extension of the base, the said extension comprising an auxiliary concave surface disposed over a portion of its length within the coil and directed towards the external convex surface, the end of the second movable arm becoming disposed, when the coil is energised, in a space between the curved external surface of the second fixed arm, the auxiliary concave surface and the transverse fixed surface, the magnetic attraction of the said end becoming effective when it is engaged substantially half way into said space.
Claim 2
Dependent Claim
262 words
An electromagnet constituted by (i) a coil the inner zone of which has a certain axial length, and (ii) a magnetic structure, said magnetic structure comprising (a) a fixed core in the form of a "U" having a base joining a first fixed arm placed externally of the coil, and a second fixed arm having a convex external surface disposed over substantially the whole of its length, in the interior of the coil, and (b) a movable armature in the form of a "U" having a first movable arm of which one end mounted on a pivot is associated with the first fixed arm by a small air gap and a second movable arm having a first internal curved surface which is spaced by a first variable air gap from the external curved surface of the second fixed arm, and of which the end is provided with a pole surface which is transverse with respect to said first variable air gap and which is spaced by a second variable air gap from a transverse fixed surface on an extension of the base, the said extension comprising an auxiliary concave surface disposed over a portion of its length within the coil and directed towards the external convex surface, the end of the second movable arm becoming disposed, when the coil is energised, in a space between the curved external surface of the second fixed arm, the auxiliary concave surface and the transverse fixed surface, the magnetic attraction of the said end becoming effective when it is engaged substantially half way into said space.
Claim 3
Dependent Claim
140 words
An electromagnet, according to claim 1, in which the external convex surface of the second fixed arm comprises a first portion adjacent to the transverse surface and a second portion extending from the first portion up to the end of the second fixed arm, the centre of curvature of the second portion having disposed substantially on the median line joining that point which is common to the two portions of the surface which is substantially in the axis of the coil and the said end, the radius of curvature of the said second portion being between 1.3 and 2 times the distance separating the pivot from the said end, the centre of curvature of the second portion being disposed in a quadrant of which the apex is on the pivot and which is opposite to the quadrant containing the armature.
Claim 4
Dependent Claim
50 words
An electromagnet, according to claim 2, in which the centres of curvature of the first portion of the fixed arm and of the auxiliary concave surface are disposed on a straight line passing through the pivot and through the point common to the two portions of the external convex surface.
Claim 5
Dependent Claim
42 words
An electromagnet, according to claim 3, in which the section of the first fixed arm adjacent to the base, the transverse surface and the section of the extension are each equal to 1/3 of the section of the opening of the coil.
Claim 6
Dependent Claim
33 words
An electromagnet, according to claim 1 wherein the centre of rotation of the armature is close to the plane passing through the axial centre of the coil and perpendicular to the coil axis.
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) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |