US4806218A
Expired / Lapsed
US
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Method of coating cathode wires by cataphoretic coating
Assignee: Panasonic Holdings Corp
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Filing: 1987-09-04
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Granted: 1989-02-21
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Expires: 2007-09-04
Abstract
Abstract Oxide cathode wires are produced by coating tungsten wires with emissive material by cataphoretic coating. It is important for the coating to have a substantially uniform thickness over the entire surface of the wire. This is achieved in a simple manner by reversing the polarity of the direction of current flow for a short time at the beginning of the coating process, so that the tungsten wire to be coated is connected as an anode. The remainder of the coating process is performed in a known manner with a tungsten wire connected as a cathode.
Inventors
- 👤 Herbert Hemminger
- 👤 Michael Schlipf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:35
CPC Classifications
C; C25; C25D; C25D13/00; C25D13/12; C25D13/16; C25D13/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A method of coating cathode wires by cataphorectically coating wires with an emissive material suspended in an electrolyte, comprising the steps of: suspending a wire in a suspension of emissive material in an electrolyte; connecting the wire as an anode for about a fraction of a second to about a few seconds; and thereafter connecting the wire as a cathode in the same suspension, whereby a uniform coating of the emissive material is cataphoretically coated on said wire.
Claim 2
Independent Claim
78 words
A method of coating cathode wires by cataphorectically coating wires with an emissive material suspended in an electrolyte, comprising the steps of: suspending a wire in a suspension of emissive material in an electrolyte; connecting the wire as an anode for about a fraction of a second to about a few seconds; and thereafter connecting the wire as a cathode in the same suspension, whereby a uniform coating of the emissive material is cataphoretically coated on said wire.
Claim 3
Dependent Claim
20 words
A method as described in claim 1, wherein the electrolyte contains diethyl carbonate, diethyl oxalate, ethyl alcohol, acetone and methanol.
Claim 4
Dependent Claim
15 words
A method as described in claim 2, wherein a counterelectrode of stainless steel is used.
Claim 5
Dependent Claim
24 words
A method as described in claim 3, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
Claim 6
Dependent Claim
24 words
A method as described in claim 2, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
Claim 7
Dependent Claim
15 words
A method as described in claim 1, wherein a counterelectrode of stainless steel is used.
Claim 8
Dependent Claim
24 words
A method as described in claim 6, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
Claim 9
Dependent Claim
27 words
A method as described in claim 1, wherein the emissive material is selected from a group consisting of barium carbonate, strontium carbonate, calcium carbonate and mixtures thereof.
Claim 10
Dependent Claim
15 words
A method as described in claim 8, wherein a counterelectrode of stainless steel is used.
Claim 11
Dependent Claim
24 words
A method as described in claim 9, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
Claim 12
Dependent Claim
24 words
A method as described in claim 8, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
Claim 13
Dependent Claim
24 words
A method as described in claim 1, wherein the wires to be coated are subjected to a pretreatment consisting of washing and reductive annealing.
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) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |