Patent US2248904A successfully refreshed from Google Patents.
Patent EP0223204A2 successfully refreshed from Google Patents.
US4048713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making compact electric coils
Assignee: Individual
•
Filing: 1975-06-09
•
Granted: 1977-09-20
•
Expires: 1995-06-09
Abstract
Abstract A method of producing a compact electric coil such as a voice coil for loudspeakers, whereby a coil member is wound of ordinary round wire having a coating of a thermoplastic or thermosetting bonding material, whereafter the coil member mounted on a mandrel is heated together with the mandrel and thereafter cooled from its outside so as to crimp around the mandrel while this is still warm and expanded. Hereby the round wire will be forced inwardly with high force so as to get cross sectionally deformed to fill out the available space to a very large degree, and the bonding material sets so as to hold the coil in its compacted shape whereby a coil of high rigidity and heat conductivity is produced. The coil is easily retractable from the mandrel upon further cooling of the latter.
Inventors
- 👤 Mogens Hvass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:26
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; H01F41/06; H01F41/077; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005; Y10T29/4902; Y10T29/49071
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
A method of producing compact electric coils having a high space factor, such as voice coils for loudspeakers, whereby the coil is wound in winding layers of insulated wire of round cross sectional shape, characterized in that the method comprises the steps of arranging a coil on a mandrel filling out the coil, subjecting the mandrel and coil to a differential thermal treatment to cause, without a counter pressure being exerted on the wire, a radial compression of the wire until the wire in each winding layer becomes deformed at surface portions thereof so as to be pressed substantially flat against the surfaces of the adjoining wire portions of the adjacent winding layers.
Claim 2
Independent Claim
113 words
A method of producing compact electric coils having a high space factor, such as voice coils for loudspeakers, whereby the coil is wound in winding layers of insulated wire of round cross sectional shape, characterized in that the method comprises the steps of arranging a coil on a mandrel filling out the coil, subjecting the mandrel and coil to a differential thermal treatment to cause, without a counter pressure being exerted on the wire, a radial compression of the wire until the wire in each winding layer becomes deformed at surface portions thereof so as to be pressed substantially flat against the surfaces of the adjoining wire portions of the adjacent winding layers.
Claim 3
Dependent Claim
36 words
A method according to claim 1, characterized in that the step of subjecting the mandrel to a differential thermal treatment comprises: thermally causing said mandrel to expand, and cooling the coil with the mandrel still expanded.
Claim 4
Dependent Claim
73 words
A method according to claim 2, characterized in that the mandrel is heated to a temperature sufficient to soften the insulation coating of the wire, and in that the coil is cooled to a temperature sufficient for solidification of the insulation coating and for contraction without a corresponding contraction of the mandrel, the method further comprising cooling the mandrel subsequent to the cooling of the wire, and removing the coil from the mandrel.
Claim 5
Independent Claim
106 words
A method of compacting an electric coil to increase the space factor thereof, the coil being comprised of a plurality of turns of round cross-sectional wires arranged in layers, the method comprising the steps of: arranging a coil on a mandrel filling out the coil, subjecting the mandrel and coil to a differential thermal treatment to effectively cause the coil windings to be tightened about the mandrel to such a degree that the resulting radial forces on the wire of the coil are sufficient to effect a cross-sectional deformation of the wire in each of the turns against adjacent turns and therewith compaction of the windings.
Claim 6
Independent Claim
106 words
A method of compacting an electric coil to increase the space factor thereof, the coil being comprised of a plurality of turns of round cross-sectional wires arranged in layers, the method comprising the steps of: arranging a coil on a mandrel filling out the coil, subjecting the mandrel and coil to a differential thermal treatment to effectively cause the coil windings to be tightened about the mandrel to such a degree that the resulting radial forces on the wire of the coil are sufficient to effect a cross-sectional deformation of the wire in each of the turns against adjacent turns and therewith compaction of the windings.
Claim 7
Dependent Claim
48 words
A method according to claim 4, characterized in that the step of subjecting the mandrel and coil to a differential thermal treatment includes heating the mandrel to cause a predetermined expansion thereof, cooling the coil with the mandrel still expanded, and contracting the mandrel for releasing the coil.
Claim 8
Dependent Claim
23 words
A method according to claim 5, characterized in that the step of contracting the mandrel includes directing a cooling medium at the mandrel.
Claim 9
Dependent Claim
35 words
A method according to claim 5, characterized in that the coil wire is insulated with a thermo-softenable insulation material, and in that the mandrel is heated to a temperature sufficient to soften the insulation matrial.
Claim 10
Dependent Claim
54 words
A method according to claim 7, characterized in that the step of heating the mandrel includes heating the mandrel from the inside thereof and allowing a transfer of heat from the mandrel to the coil, and wherein the step of cooling the coil includes supplying a cooling medium to the outside of the coil.
References Cited (Backward Citations)
US1041293A
Cited
US3050613A
Cited
US3298096A
Cited
US3383900A
Cited
US3348183A
Cited
US3541682A
Cited
US3667118A
Cited
US3845547A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |