Patent US3857145A successfully refreshed from Google Patents.
US3857145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing spark plug center electrode
Assignee: Denso Corp
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Filing: 1972-08-01
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Granted: 1974-12-31
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Expires: 1992-08-01
Abstract
Abstract A method for the production of a spark plug center electrode comprising steps of forming a good heat conducting metal piece into a convex or protrudent shape and a corrosion-resistant metal piece into a concave or cup-shaped shape, preparing an extrusion material by fitting the protruding portion of the convex-shaped good heat conducting metal piece into the recessed portion of the concave-shaped corrosion-resistant metal piece, and coldextruding and extrusion material into a rod form such that the corrosion-resistant metal covers the good heat conducting metal.
Inventors
- 👤 T Yamaguchi
- 👤 K Izumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:10
CPC Classifications
H; H01; H01T; H01T21/00; H01T21/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
179 words
A method of producing a spark plug center electrode of the type which comprises a core member consisting of a good heat conducting metal having a corrosion-resistant metal enclosing the sparking end portion and the side portions thereof, said method comprising the steps of: Forming said good heat conducting metal into a protrudent shape by only one plastic-working step, the protrudent portion of the shaped good heat conducting metal being at least as great as one-half the height of said shaped good heat conducting metal, forming a corrosion-resistant metal piece into a cup shape by only one plastic working step, the depth of the cavity of said cup-shaped metal being at least as great as one-half the height of said cup-shaped metal, preparing an extrusion metal by fitting the protruding portion of said protrudent shaped good heat conducting metal piece into the recess portion of said cup-shaped corrosion resistant metal piece, and shaping said extrusion metal into a rod formed by the process of cold extrusion, wherein said good heat conducting metal is covered by said corrosion resistant metal.
Claim 2
Independent Claim
179 words
A method of producing a spark plug center electrode of the type which comprises a core member consisting of a good heat conducting metal having a corrosion-resistant metal enclosing the sparking end portion and the side portions thereof, said method comprising the steps of: Forming said good heat conducting metal into a protrudent shape by only one plastic-working step, the protrudent portion of the shaped good heat conducting metal being at least as great as one-half the height of said shaped good heat conducting metal, forming a corrosion-resistant metal piece into a cup shape by only one plastic working step, the depth of the cavity of said cup-shaped metal being at least as great as one-half the height of said cup-shaped metal, preparing an extrusion metal by fitting the protruding portion of said protrudent shaped good heat conducting metal piece into the recess portion of said cup-shaped corrosion resistant metal piece, and shaping said extrusion metal into a rod formed by the process of cold extrusion, wherein said good heat conducting metal is covered by said corrosion resistant metal.
Claim 3
Dependent Claim
33 words
A method according to claim 1 including a further step of cutting said cold-extruded product at that portion thereof where the length of said corrosion-resistant metal covering said good heat conducting metal terminates.
Claim 4
Dependent Claim
59 words
A method according to claim 2 including a further step of subjecting the center electrode comprising the core member consisting of said good heat conducting metal and the covering member covering said core member and consisting of said corrosion-resistant metal to a heading operation to form thereon a collar portion for assemblying said center electrode into a spark plug.
Claim 5
Dependent Claim
22 words
A method according to claim 3, wherein said good heat conducting metal consists of copper and said corrosion-resistant metal consists of nickel.
Claim 6
Independent Claim
184 words
A method of producing a spark plug center electrode of the type which comprises a core member consisting of a good heat conducting metal having a corrosion-resistant metal enclosing the sparking end portion and the side portions thereof, said method comprising the steps of: forming said good heat conducting metal into a protrudent shape by only one plastic-working step wherein the protruding portion of said good heat conducting metal is at least as great as one-half the length of the shaped good heat conducting metal, forming a corrosion-resistant metal piece into a complementary shape having a cavity therein for receiving said protruding portion of said good heat conducting metal, the depth of said cavity being at least as great as one-half the height of said complementary-shaped metal piece, preparing an extrusion metal by fitting the protruding portion of said protrudent-shaped good heat conducting metal piece into the cavity portion of said complementary-shaped corrosion-resistant metal piece, and shaping said extrusion metal into a rod formed by the process of cold extrusion, wherein said good heat conducting metal is substantially uniformly covered by said corrosion-resistant metal.
Claim 7
Independent Claim
184 words
A method of producing a spark plug center electrode of the type which comprises a core member consisting of a good heat conducting metal having a corrosion-resistant metal enclosing the sparking end portion and the side portions thereof, said method comprising the steps of: forming said good heat conducting metal into a protrudent shape by only one plastic-working step wherein the protruding portion of said good heat conducting metal is at least as great as one-half the length of the shaped good heat conducting metal, forming a corrosion-resistant metal piece into a complementary shape having a cavity therein for receiving said protruding portion of said good heat conducting metal, the depth of said cavity being at least as great as one-half the height of said complementary-shaped metal piece, preparing an extrusion metal by fitting the protruding portion of said protrudent-shaped good heat conducting metal piece into the cavity portion of said complementary-shaped corrosion-resistant metal piece, and shaping said extrusion metal into a rod formed by the process of cold extrusion, wherein said good heat conducting metal is substantially uniformly covered by said corrosion-resistant metal.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |