US4049024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mandrel and method of manufacturing same
Assignee: Osram Sylvania Inc
•
Filing: 1976-06-04
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Granted: 1977-09-20
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Expires: 1996-06-04
Abstract
Abstract A mandrel and a method for its manufacture and its use in manufacturing filament coils for electric lamps is disclosed. The mandrel, having a base core containing iron, is protected from diffusion of iron into a filament wire wound thereabout by a first coating of copper and a second coating of tungsten over the first, base metal. The process of coating the tungsten over the copper coating is improved by employing small amounts of copper ion contaminant in the electroplating solution. After a filament wire is wound around and annealed over this mandrel, the mandrel is selectively dissolved leaving the shaped filament coil, substantially free of extraneous metal impurities.
Inventors
- 👤 James J. Auborn
- 👤 Elizabeth Ann Trickett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:57
CPC Classifications
H; H01; H01K; H01K3/00; H01K3/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
29 words
A process which comprises directly electrodepositing tungsten onto a copper substrate metal, from a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/l of copper ion.
Claim 2
Dependent Claim
29 words
A process which comprises directly electrodepositing tungsten onto a copper substrate metal, from a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/l of copper ion.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the copper substrate metal contains iron.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the copper substrate metal is copper coated steel.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the solution is an aqueous alkaline solution.
Claim 6
Dependent Claim
14 words
The process of claim 4 wherein the tungsten electrodeposition solution is aqueous tungsten trioxide.
Claim 7
Dependent Claim
19 words
The process of claim 5 wherein the concentration of copper ion is from about 0.1 to about 0.3 gms/l.
Claim 8
Dependent Claim
13 words
The process of claim 6 wherein the copper substrate is copper coated steel.
Claim 9
Dependent Claim
20 words
The process of claim 1 wherein the copper ion is provided by reversing the polarity prior to electrodeposition of tungsten.
Claim 10
Dependent Claim
15 words
The process of claim 1 conducted at from about 85° C. to about 105° C.
Claim 11
Dependent Claim
21 words
The process of claim 1 where said tungsten solution contains about 0.5 M to about 0.6 M of the tungsten species.
Claim 12
Dependent Claim
25 words
The process of claim 1 where the tungsten is electrodeposited from solution at a current density of about 0.025 to about 0.75 A/cm 2 .
Claim 13
Dependent Claim
24 words
The process of claim 1 where said electrodeposition is conducted at a sufficiently high electrical potential to cause evolution of gas at the electrodes.
Claim 14
Dependent Claim
41 words
A process for making mandrels useful for making filaments for incandescent lamps comprising the step of directly electrodepositing tungsten onto a copper substrate metal from a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/l of copper ion.
Claim 15
Dependent Claim
41 words
A process for making mandrels useful for making filaments for incandescent lamps comprising the step of directly electrodepositing tungsten onto a copper substrate metal from a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/l of copper ion.
Claim 16
Dependent Claim
54 words
A process of making incandescent lamp filaments comprising the steps of directly electroplating a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/1 of copper ion, winding filament wire around the tungsten coating, annealing the filament wire winding, and selectively dissolving the tungsten coated copper substrate metal from the filament wire.
Claim 17
Dependent Claim
54 words
A process of making incandescent lamp filaments comprising the steps of directly electroplating a tungsten electrodeposition solution contaminated with from about 0.1 to about 0.3 gms/1 of copper ion, winding filament wire around the tungsten coating, annealing the filament wire winding, and selectively dissolving the tungsten coated copper substrate metal from the filament wire.
Claim 18
Dependent Claim
14 words
The process of claim 14 wherein the copper substrate metal is copper coated steel.
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) | 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 |