US3867487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carburetor for internal combustion engines
Assignee: Yamaha Motor Co Ltd
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Filing: 1973-11-20
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Granted: 1975-02-18
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Expires: 1993-11-20
Abstract
Abstract A carburetor for internal combustion engines of the type including the idling system, provides guide passage means for conducting the flow of fuel, which tends to adhere in the state of liquid upon the inner wall surface of the throttle bore in idling or low-load operations of the associated engine, down onto the bottom area of the throttle valve, so that the whole of liquid fuel be thoroughly atomized before leaving the carburetor.
Inventors
- 👤 Hiromitsu Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:27
CPC Classifications
F; F02; F02M; F02M3/00; F02M3/08; F02M33/00; F02M33/02; F02M33/04; Y; Y10; Y10S; Y10S261/00; Y10S261/55
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
195 words
A carburetor for internal combustion engines of the type comprising an induction pipe horizontally arranged downstream of the Venturi portion, a butterfly-type throttle valve journal supported by said induction pipe, and an idle port on the upper wall of the induction pipe being opened in the induction pipe adjacent the position of the top peripheral edge of the throttle valve to be assumed when the valve is closed or slightly opened, characterized by the provision of passage means formed around the inner wall surface of the induction pipe, said passage means functioning to prevent fuel discharged through the idle port from flowing along the upper inner wall surface of the induction pipe in the downstream direction and conduct said flow of fuel downwardly to and above the junctures between a valve shaft for supporting said throttle valve and the induction pipe wall, and further passage means formed around the journal portions of the valve shaft, said further passage means functioning to conduct said fuel flow, which has reached above the valve shaft, to the lower central surface area of the throttle valve, while turning the flow apart from the inner wall of the induction pipe.
Claim 2
Dependent Claim
195 words
A carburetor for internal combustion engines of the type comprising an induction pipe horizontally arranged downstream of the Venturi portion, a butterfly-type throttle valve journal supported by said induction pipe, and an idle port on the upper wall of the induction pipe being opened in the induction pipe adjacent the position of the top peripheral edge of the throttle valve to be assumed when the valve is closed or slightly opened, characterized by the provision of passage means formed around the inner wall surface of the induction pipe, said passage means functioning to prevent fuel discharged through the idle port from flowing along the upper inner wall surface of the induction pipe in the downstream direction and conduct said flow of fuel downwardly to and above the junctures between a valve shaft for supporting said throttle valve and the induction pipe wall, and further passage means formed around the journal portions of the valve shaft, said further passage means functioning to conduct said fuel flow, which has reached above the valve shaft, to the lower central surface area of the throttle valve, while turning the flow apart from the inner wall of the induction pipe.
Claim 3
Dependent Claim
134 words
A carburetor for internal combustion engines according to claim 1, characterized by that when the throttle valve assumes the closed or slightly opened position, said passage means provided around the inner wall surface of the induction pipe is such arranged as extending from above one journal portion of the valve shaft and behind the downstream surface of the throttle valve, to above the other journal portion of the valve shaft, passing closely downstream of said idle port; while said further passage means on the valve shaft extending slightly downstream of said surface of the throttle valve, as inclined with respect to the shaft axis from each upper end portion of the valve shaft located outwardly of the inner wall surface of the induction pipe, toward the lower inner central portion of the induction pipe.
Claim 4
Dependent Claim
40 words
A carburetor for internal combustion engines according to claim 2, characterized by that said passage means provided around the inner wall surface of the induction pipe consists of a groove formed on the inner wall surface of the induction pipe.
Claim 5
Dependent Claim
26 words
A carburetor for internal combustion engines according to claim 3, characterized by that said groove is of substantially U-shaped section opened inwardly of the induction pipe.
Claim 6
Dependent Claim
76 words
A carburetor for internal combustion engines according to claim 4, characterized by that said groove of U-shaped section is such shaped over the length thereof that one side wall surface of said groove on the upstream side has a gradual increase of gradient formed from the inner surface of the induction pipe to the bottom surface of the groove while the varying rate of said gradient being increased toward the lower portion of the induction pipe.
Claim 7
Dependent Claim
40 words
A carburetor for internal combustion engines according to claim 2, characterized by that said passage means provided on the innEr wall surface of the induction pipe consists of a member secured on the inner wall surface of the induction pipe.
Claim 8
Dependent Claim
73 words
A carburetor for internal combustion engines according to claim 6, characterized by that said member secured on the inner wall surface of the induction pipe is in the form of a semi-cylindrical member which has the outer circumferential surface substantially identical to the inner circumferential surface of the induction pipe, and the end surface of said member on the upstream side is substantially perpendicular to the inner wall surface of the induction pipe.
Claim 9
Dependent Claim
70 words
A carburetor for internal combustion engines according to claim 6, characterized by that said member secured on the inner wall surface of the induction pipe has the outer circumferential surface substantially identical to the inner circumferential surface of the induction pipe, the end surface of said member on the upstream side forming, in cooperation with the inner wall surface of the induction pipe, a groove of U-shaped section opened upstream.
Claim 10
Dependent Claim
112 words
A carburetor for internal combustion engines according to claim 2, characterized by that said passage means provided around the inner wall surface of the induction pipe consists of a groove formed on the inner wall surface of the induction pipe and a semi-cylindrical member secured on the inner wall surface of the induction pipe in such a manner that over the length of the groove, at least a half width of the opening, on the upstream side, of the groove opened inwardly is in direct communication with the interior of the induction pipe, the outer circumferential surface of said member being substantially identical to the inner circumferential surface of the induction pipe.
Claim 11
Dependent Claim
72 words
A carburetor for internal combustion engines according to claim 9, characterized by that said groove is of substantially U-shaped section while said semi-cylindrical member being arranged such that the end surface of said member on the upstream side being substantially perpendicular to the inner wall surface of the induction pipe, and over the length of the groove, a half width of the opening on the downstream side being closed by said member.
Claim 12
Dependent Claim
77 words
A carburetor for internal combustion engines according to claim 9, characterized by that said groove provided around the inner wall surface of the induction pipe and a groove formed on the outer side of the upstream end portion of said semi-cylindrical member in combination forms a passage generally closed such that over the upper half length, said passage is opened in the upstream direction with a gradual increase of the opening toward the top of the passage.
Claim 13
Dependent Claim
67 words
A carburetor for internal combustion engines according to claim 2, characterized by that said further passage means on the valve shaft each extends from a portion of the inner wall surface of the induction pipe, where the outer circumferential edge of said valve shaft intersects the induction pipe, to the downstream surface of said throttle valve spaced inwardly from said inner wall surface of the induction pipe.
Claim 14
Dependent Claim
54 words
A carburetor for internal combustion engines according to claim 12, characterized by that said further passage means on the valve shaft each is substantially perpendicular to the downstream surface of said throttle valve while said passage means each consists of a plane surface which is adapted to turn upward when said throttle valve closes.
Claim 15
Dependent Claim
124 words
A carburetor for internal combustion engines according to claim 13, characterized by that said throttle valve is supported by the valve shaft as being inserted through an axial opening provided on a portion of said valve shaft extending within the induction pipe, said axial opening having the width corresponding to the thickness of said throttle valve and the length corresponding to the minor diameter of said valve, said portion of the valve shaft, at the downstream side of the valve, having a cross section of trapezoid with a plane surface parallel to the downstream surface of the throttle valve, while the inner end surface of each journal portion projecting inwardly of the induction pipe so as to form passage means on the valve shaft.
Claim 16
Dependent Claim
76 words
A carburetor for internal combustion engines according to claim 13, characterized by that said portion of the valve shaft exposed within the induction pipe has a semicircular section with the chord extending at the downstream side, said throttle valve being secured on said chord containing surface of the valve shaft, while the inner end surface of each journal portion projecting inwardly of the induction pipe so as to form the passage means on the valve shaft.
Claim 17
Dependent Claim
105 words
A carburetor for internal combustion engines according to claim 12, characterized by that said passage means consists of passages of circular section formed through the valve shaft so that the outer extreme end of the upper opening of each passage formed on the valve shaft is positioned outwardly of the inner wall surface of the induction pipe and the inner extreme end of said upper opening of each passage is positioned inwardly of the inner wall surface of the induction pipe, while the outer extreme end of the lower opening of each passage is positioned inwardly of the inner wall surface of the induction pipe.
Claim 18
Dependent Claim
89 words
A carburetor for internal combustion engines according to claim 2, characterized by that said throttle valve is in continuous communication with said further passage means on the valve shaft, while said throttle valve being provided on the downstream surface thereof with passage means for conducting a flow of liquid fuel, which has been conducted onto the throttle valve by said passage means provided on the induction pipe and valve shaft, to the downstream surface of said throttle valve spaced inwardly from the inner wall surface of the induction pipe.
Claim 19
Dependent Claim
84 words
A carburetor for internal combustion engines according to claim 17, characterized by that said passage means provided on the downstream surface of the throttle valve consists of members each having a plane top surface which continuously extends from the inner end portion of said further passage means on the valve shaft in the diagonal downward direction toward the lower inner central portion of the induction pipe, the inner end of each member being positioned inwardly of the outer peripheral edge of the throttle valve.
Claim 20
Dependent Claim
41 words
A carburetor for internal combustion engines according to claim 14, characterized by that said passage means provided around the inner wall surface of the induction pipe consists of a groove having a substantially U-shaped section opened inwardly of the induction pipe.
Claim 21
Dependent Claim
103 words
A carburetor for internal combustion engines according to claim 16, characterized by that said passage means provided around the inner wall surface of the induction pipe consists of a groove of substantially U-shaped section opened inwardly of the pipe, said groove of U-shaped section being such shaped over the length thereof that one side wall surface of said groove on the upstream side has a gradual increase of gradient formed from the inner wall surface of the induction pipe to the bottom surface of the groove, while the varying rate of said gradient being increased toward the lower portion of the induction pipe.
Claim 22
Dependent Claim
108 words
A carburetor for internal combustion engines according to claim 18, characterized by that said passage means provided around the inner wall surface of the induction pipe has a substantially U-shaped section opened inwardly of the induction pipe, while there being provided a semi-cylindrical member having the outer circumferential surface substantially identical to the inner circumferential surface of the induction pipe, the end surface of said member on the upstream side being substantially perpendicular to the inner wall surface of the induction pipe, said member being positioned so as to substantially close a half width of the groove opening, on the downstream side, over the length of the groove.
Claim 23
Dependent Claim
102 words
A carburetor for internal combustion engines according to claim 15, charActerized by that said passage means provided around the inner wall surface of the induction pipe consists of a groove formed on the inner wall surface of the induction pipe and a further groove formed on the outer side of the upstream end portion of a semi-cylindrical member secured on the inner wall surface of the induction pipe, thereby forming a generally closed passage such that over the upper half length, said passage is opened in the upstream direction with a gradual increase of the opening toward the top of the passage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |