Patent US3788288A successfully refreshed from Google Patents.
US3788288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carburetor throttle valve positioner
Assignee: Ford Motor Co
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Filing: 1972-06-23
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Granted: 1974-01-29
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Expires: 1992-06-23
Abstract
Abstract One embodiment of a downdraft type carburetor has an idle system discharge port that is straddled by the idle speed and closed throttle positions of the throttle valve so as to permit idle speed fuel and air flow in one position and no flow in the other position; another embodiment has a conventional idle system with a transfer port straddling the edge of the throttle valve in the idle speed position of the throttle valve so as to permit normal idle speed fuel and air flow in this position, while being closed off or having its area that is exposed to the vacuum signal reduced in the closed position of the throttle valve to reduce idle channel flow; the two positions being controlled by a servo operatively engaging the throttle valve; the servo operation being controlled by intake manifold vacuum during engine deceleration operation to close the throttle valve, or upon engine shut off interrupting the ignition circuit to close the throttle valve with a subsequent return of the throttle valve to its curb idle position for engine restarting.
Inventors
- 👤 R Harrison
- 👤 M Lunsford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:16
CPC Classifications
F; F02; F02M; F02M3/00; F02M3/06; F02M3/07; F02M3/02; F02M3/04; Y; Y10; Y10S; Y10S123/00; Y10S123/11
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
297 words
A carburetor throttle valve positioner comprising, in combination, an engine carburetor having an induction passage open to atmospheric pressure at one end and adapted to be connected to an engine intake manifold at the opposite end so as to be subject to engine vacuum varying in level from ambient atmospheric pressure at engine shutdown to a maximum subatmospheric pressure level during engine deceleration operating conditions, a throttle valve rotatably mounted across said passage and movable from a first position essentially closing the induction passage to an engine idle speed position and beyond to a wide open throttle position, and return, for controlling flow through said passage, the carburetor including an idle fuel/air mixture passage connected to the induction passage around the throttle valve and having transfer port means straddling at times the edge of the throttle valve and having a discharge end connected to the induction passage below the first closed throttle position so as to always provide an idle air/fuel mixture so long as the engine is running regardless of the position of the throttle valve whereby the idle passage is subjected to the engine to a manifold vacuum signal at one level when the throttle is at its idle speed position and a lower level vacuum signal when the throttle valve is in the first closed position and control means to move said throttle valve to said positions, said control means including first means operatively biasing said throttle valve to an open throttle position, and power means responsive to engine shutdown operation for effecting initially a movement of said throttle valve to its first closed throtle position to reduce the flow of a fuel/air mixture through said passage, and subsequently a movement of said throttle valve to an open position for an engine starting operation.
Claim 2
Dependent Claim
297 words
A carburetor throttle valve positioner comprising, in combination, an engine carburetor having an induction passage open to atmospheric pressure at one end and adapted to be connected to an engine intake manifold at the opposite end so as to be subject to engine vacuum varying in level from ambient atmospheric pressure at engine shutdown to a maximum subatmospheric pressure level during engine deceleration operating conditions, a throttle valve rotatably mounted across said passage and movable from a first position essentially closing the induction passage to an engine idle speed position and beyond to a wide open throttle position, and return, for controlling flow through said passage, the carburetor including an idle fuel/air mixture passage connected to the induction passage around the throttle valve and having transfer port means straddling at times the edge of the throttle valve and having a discharge end connected to the induction passage below the first closed throttle position so as to always provide an idle air/fuel mixture so long as the engine is running regardless of the position of the throttle valve whereby the idle passage is subjected to the engine to a manifold vacuum signal at one level when the throttle is at its idle speed position and a lower level vacuum signal when the throttle valve is in the first closed position and control means to move said throttle valve to said positions, said control means including first means operatively biasing said throttle valve to an open throttle position, and power means responsive to engine shutdown operation for effecting initially a movement of said throttle valve to its first closed throtle position to reduce the flow of a fuel/air mixture through said passage, and subsequently a movement of said throttle valve to an open position for an engine starting operation.
Claim 3
Dependent Claim
80 words
A throttle positioner as in claim 1, including second means biasing said throttle valve to a closed position, said power means including a vacuum servo having a spring extended, vacuum retracted, piston rod in its extended position operatively engaging and moving said throttle valve to said engine starting position, and in its retracted position permitting said second means to close said throttle valve, said vacuum means operatively acting on said rod to retract said rod in response to engine shutdown.
Claim 4
Dependent Claim
17 words
A throttle positioner as in claim 2, including means connecting said vacuum means to said intake manifold.
Claim 5
Dependent Claim
109 words
A throttle positioner as in claim 1, said power means including a vacuum servo, conduit means connecting said servo to said intake manifold vacuum, on-off valve means in said conduit means spring biased to an on position in response to engine shutdown to connect vacuum to said servo to close said throttle valve, and a vacuum reservoir in said conduit means for maintaining a vacuum on said servo of a level sufficient to close said throttle valve for a predetermined period after decay of the intake manifold vacuum until the decay in vacuum in said reservoir permits said first means to bias said throttle valve to said open position.
Claim 6
Dependent Claim
56 words
A throttle positioner as in claim 4, including engine ignition means including an ignition switch and an electrical circuit operably connecting said switch to said on-off valve for effecting movement of the same to an off position upon closing of said switch to effect engine start-up to block the flow of said vacuum to said servo.
Claim 7
Dependent Claim
47 words
A throttle positioner as in claim 5, including manifold vacuum actuated circuit interrupting means operable in response to the attainment of a high vacuum level indicative of engine decelerating operation to break said circuit means and effect opening of said on-off valve to close said throttle valve.
Claim 8
Dependent Claim
59 words
A throttle positioner as in claim 5, said on-off valve including spring means biasing said latter valve to an on position permitting application of vacuum to said servo, said latter valve including electrical means energized in response to closing of said ignition switch to move said latter valve to an off position blocking application of vacuum to said servo.
Claim 9
Dependent Claim
38 words
A throttle positioner as in claim 4, including flow restricting means in said conduit means between said manifold vacuum and said reservoir for delaying decay of vacuum in said reservoir upon decay of manifold vacuum at engine shutdown.
References Cited (Backward Citations)
US3491737A
Cited
US3682148A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |