US3708683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diesel engine starting switch and circuit
Assignee: Thermo King Corp
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Filing: 1971-05-12
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Granted: 1973-01-02
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Expires: 1991-05-12
Abstract
Abstract A diesel engine pre-heating, starting and running switch and circuit is comprised of a three pole, three position switch connecting the battery source to the engine starter, the electric fuel actuator and auxiliary equipment, the pre-heating glow plugs and a safety circuit that can be energized only when the engine is running, the fuel actuator can be energized only in the run and start positions of the switch, the starter can be energized only in the start position of the switch, and the glow plugs can be energized only in the pre-heat and starting positions of the switch.
Inventors
- 👤 L Howland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:22
CPC Classifications
F; F02; F02P; F02P19/00; F02P19/02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
307 words
A diesel engine pre-heating, starting and running switch and circuit comprising, a three position switch having first, second and third poles, a source of current, a starter solenoid, an electrically operated engine fuel actuator, at least one engine pre-heating glow plug, a safety circuit having a normally closed contact to be connected to be energized only when the engine is running, means connecting said fuel actuator in series with said normally closed contact and the contacts of a main control switch to one terminal of said source, at least one alarm safety switch having normally open contacts, means electrically connecting together the first and second poles of said three position switch, means connecting said third pole to said one terminal of said source, means connecting the second and third switch positions of said first pole in series with said normally closed contact and said main switch to said one terminal of said source, means connecting the second position of said second pole in series with the said safety circuit and said at least one safety switch normally open contacts to the other terminal of said source, means connecting the third position of said second pole in series with said starter solenoid and the other terminal of said source, and means connecting the first and third positions of the second pole of said switch in series with said at least one glow plug to the other terminal of said source whereby said starting solenoid is connected to be energized only when the three position switch is in the third position, said at least one glow plug is connected to be energized to pre-heat the engine only when said switch is in the first or third positions, and said safety circuit is connected to said at least one safety switch only when said switch is in the second position.
Claim 2
Dependent Claim
307 words
A diesel engine pre-heating, starting and running switch and circuit comprising, a three position switch having first, second and third poles, a source of current, a starter solenoid, an electrically operated engine fuel actuator, at least one engine pre-heating glow plug, a safety circuit having a normally closed contact to be connected to be energized only when the engine is running, means connecting said fuel actuator in series with said normally closed contact and the contacts of a main control switch to one terminal of said source, at least one alarm safety switch having normally open contacts, means electrically connecting together the first and second poles of said three position switch, means connecting said third pole to said one terminal of said source, means connecting the second and third switch positions of said first pole in series with said normally closed contact and said main switch to said one terminal of said source, means connecting the second position of said second pole in series with the said safety circuit and said at least one safety switch normally open contacts to the other terminal of said source, means connecting the third position of said second pole in series with said starter solenoid and the other terminal of said source, and means connecting the first and third positions of the second pole of said switch in series with said at least one glow plug to the other terminal of said source whereby said starting solenoid is connected to be energized only when the three position switch is in the third position, said at least one glow plug is connected to be energized to pre-heat the engine only when said switch is in the first or third positions, and said safety circuit is connected to said at least one safety switch only when said switch is in the second position.
Claim 3
Dependent Claim
24 words
The invention of claim 1 in which the three position switch is spring biased to the second position for normal running of the engine.
Claim 4
Dependent Claim
21 words
The invention of claim 1 in which said at least one safety switch includes a thermally operated engine high temperature switch.
Claim 5
Dependent Claim
31 words
The invention of claim 1 in which said at least one safety switch includes a low oil pressure switch whose contacts are closed when engine oil pressure is lower than desired.
Claim 6
Dependent Claim
21 words
The invention of claim 2 in which said at least one safety switch includes a thermally operated engine high temperature switch.
Claim 7
Dependent Claim
31 words
The invention of claim 2 in which said at least one safety switch includes a low oil pRessure switch whose contacts are closed when engine oil pressure is lower than desired.
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |