US3903453A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark plug incorporating a resistor for providing a low noise level
Assignee: Niterra Co Ltd
•
Filing: 1974-09-25
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Granted: 1975-09-02
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Expires: 1994-09-25
Abstract
Abstract A spark plug incorporating a resistor comprises a ceramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and extended through and sealed in a center bore provided in the insulator, said center electrode being composed of a discharge electrode portion, a conductive glass positioned at one end of the resistor, an auxiliary sealing resistor positioned at the other end of the resistor and a resistor. The conductive glass, the carbonaceous resistor and the auxiliary resistor are placed between the discharge and the terminal electrode portions so as to elongate an effective resistance portion of the resistor.
Inventors
- 👤 Kanemitsu Nishio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:58
CPC Classifications
H; H01; H01T; H01T13/00; H01T13/40; H01T13/41; H04; H04B; H04B15/00; H04B15/02; H04B15/025
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
109 words
In a spark plug comprising a ceramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and extended through and sealed in a center bore provided in the insulator, said center electrode being composed of conductive glasses and a resistor sandwiched by the conductive glasses inserted between a discharge electrode portion and a terminal electrode portion, an improvement comprising using an auxiliary resistor consisting mainly of a glass and a semiconductive material instead of at least one of said conductive glasses, whereby the length of an effective resistance portion of the resistor is elongated.
Claim 2
Dependent Claim
109 words
In a spark plug comprising a ceramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and extended through and sealed in a center bore provided in the insulator, said center electrode being composed of conductive glasses and a resistor sandwiched by the conductive glasses inserted between a discharge electrode portion and a terminal electrode portion, an improvement comprising using an auxiliary resistor consisting mainly of a glass and a semiconductive material instead of at least one of said conductive glasses, whereby the length of an effective resistance portion of the resistor is elongated.
Claim 3
Dependent Claim
17 words
A spark plug as claimed in claim 1, wherein an aggregate is added to the auxiliary resistor.
Claim 4
Dependent Claim
34 words
A spark plug as claimed in claim 2, wherein said auxiliary resistor consists of at least one metal oxide and at least one metal carbide as a semiconductor material, an aggregate and a glass.
Claim 5
Dependent Claim
27 words
A spark plug as claimed in claim 3, wherein said metal oxide is selected from the group consisting of: TiO2, Nb2O5, NiO, La2O3, ZrO2, ThO2 or ZnO.
Claim 6
Dependent Claim
23 words
A spark plug as claimed in claim 3, wherein said metal carbide is selected from thE group consisting of: TiC, SiC, or B4C.
Claim 7
Dependent Claim
22 words
A spark plug as claimed in claim 3, wherein said aggregate is selected from the group consisting of: bentonite, clay or zircon.
Claim 8
Dependent Claim
14 words
A spark plug as claimed in claim 3, wherein said glass is borosilicate glass.
Claim 9
Dependent Claim
30 words
A spark plug as claimed in claim 2, wherein said auxiliary resistor is a composition of 10-60% of the semiconductive material, 0.1-30% of the aggregate and 40-90% of the glass.
Claim 10
Dependent Claim
33 words
A spark plug as claimed in claim 1, wherein said resistor consists of 0.2-4% carbonaceous material, 10-70% aggregate and the remainder of barium borate glass, and contains less than 20% of semiconductive material.
Claim 11
Dependent Claim
17 words
A spark plug as claimed in claim 9, wherein said carbonaceous material is carbon black or glycerin.
Claim 12
Dependent Claim
15 words
A spark plug as claimed in claim 9, wherein said aggregate is clay or zircon.
Claim 13
Dependent Claim
16 words
A spark plug as claimed in claim 9, wherein said semiconductive material is TiO2 or TiC.
Claim 14
Dependent Claim
20 words
A spark plug as claimed in claim 9, wherein the resistance value of the resistor is 1-30 K Omega /cm3.
Claim 15
Dependent Claim
20 words
A spark plug as claimed in claim 3, wherein the resistance value of the auxiliary resistor is 100-3,000 Omega /cm3.
References Cited (Backward Citations)
US2864884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |