Patent US3881685A successfully refreshed from Google Patents.
US3881685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for controlling the closure of carburetor butterfly valve
Assignee: Denso Corp
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Filing: 1973-07-27
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Granted: 1975-05-06
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Expires: 1993-07-27
Abstract
Abstract A device for controlling the closure of a carburetor butterfly valve, comprising a lever pivotally movable integrally with the carburetor butterfly valve of an engine, a dash pot having a main shaft caused to make a reciprocal movement by said lever incident to the opening and closing operation of said butterfly valve and a sub-shaft operatively associated with said main shaft to make a reciprocal movement and having at one end a change-over valve for changing over the passages of fluid, said dash pot being provided with means for mechanically retarding the movement of said main shaft when said butterfly valve is closed, and a positioner which, when said butterfly valve is opened, is shifted to a position to limit the closure of said butterfly valve under the fluid pressure supplied to said positioner through the operation of said changeover valve, whereby at the time of deceleration of the engine the opening of the said butterfly valve is maintained larger than that at no-load operation of the engine for a predetermined period of time.
Inventors
- 👤 Masaru Hase
- 👤 Shinya Ishihara
- 👤 Mikio Maki
- 👤 Kiyohiko Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:16
CPC Classifications
F; F02; F02M; F02M3/00; F02M3/06; F02M3/062; F02M19/00; F02M19/12; F02M19/122; Y; Y10; Y10S; Y10S261/00; Y10S261/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
327 words
A device for controlling the closure of a carburetor butterfly valve of an engine by controlling the pivotal movement thereof comprising: a lever secured to said butterfly valve and being pivotally movable therewith; a positioner means for limiting the closure of said butterfly valve, said positioning means including a pressure chamber, a diaphragm positioned within said chamber, said diaphragm being reciprocally movable in response to fluid pressure differential in said chamber, and a stopper connected to said diaphragm and being movable between a first closure limiting position and a second closure position, said stopper when in said first closure limiting position limiting the closure of said butterfly valve, and when in said second closure position permitting the complete closure of said butterfly valve; and a dash pot, said dash pot including a main shaft, a sub-shaft having one end communicating with said main shaft through a first spring means with the other end thereof being biased toward said main shaft by a second spring means, said lever forcing said main shaft against said first spring means when said lever is rotated beyond a predetermined angle in a first butterfly opening direction, said sub-shaft being moved in response to the movement of said main shaft against the bias of said second spring means, a change-over valve mounted to said sub-shaft and being operable to vary the fluid pressure differential in said pressure chamber in response to the movement of said sub-shaft wherein said stopper is moved to said first closure limiting position only when said butterfly valve and said lever is rotated beyond said predetermined angle, means for retarding the reverse movement of said main shaft when said butterfly valve is closed after having been rotated beyond said predetermined angle, said butterfly valve being limited by said stopper for a predetermined time related to the retarding movement time of said main shaft to thereby maintain said butterfly valve at an open angle greater than the closure angle thereof.
Claim 2
Independent Claim
327 words
A device for controlling the closure of a carburetor butterfly valve of an engine by controlling the pivotal movement thereof comprising: a lever secured to said butterfly valve and being pivotally movable therewith; a positioner means for limiting the closure of said butterfly valve, said positioning means including a pressure chamber, a diaphragm positioned within said chamber, said diaphragm being reciprocally movable in response to fluid pressure differential in said chamber, and a stopper connected to said diaphragm and being movable between a first closure limiting position and a second closure position, said stopper when in said first closure limiting position limiting the closure of said butterfly valve, and when in said second closure position permitting the complete closure of said butterfly valve; and a dash pot, said dash pot including a main shaft, a sub-shaft having one end communicating with said main shaft through a first spring means with the other end thereof being biased toward said main shaft by a second spring means, said lever forcing said main shaft against said first spring means when said lever is rotated beyond a predetermined angle in a first butterfly opening direction, said sub-shaft being moved in response to the movement of said main shaft against the bias of said second spring means, a change-over valve mounted to said sub-shaft and being operable to vary the fluid pressure differential in said pressure chamber in response to the movement of said sub-shaft wherein said stopper is moved to said first closure limiting position only when said butterfly valve and said lever is rotated beyond said predetermined angle, means for retarding the reverse movement of said main shaft when said butterfly valve is closed after having been rotated beyond said predetermined angle, said butterfly valve being limited by said stopper for a predetermined time related to the retarding movement time of said main shaft to thereby maintain said butterfly valve at an open angle greater than the closure angle thereof.
Claim 3
Dependent Claim
100 words
A device according to claim 1 wherein said means for retarding the movement of said main shaft includes an enclosure divided into two chambers by a diaphragm secured to said main shaft, said two chambers being filled with a fluid, and a labyrinth groove formed in the outer peripheral surface of said main shaft, said two chambers communicating with each other through said labyrinth groove when said carburetor butterfly valve is being closed, the movement of said main shaft thereby being retarded by restricting the flow rate of said fluid through said labyrinth groove from one chamber to the other.
Claim 4
Dependent Claim
99 words
A device according to claim 1 wherein said means for retarding the movement of said main shaft includes an enclosure divided into two chambers by a diaphragm secured to said main shaft, said two chambers being filled with a fluid, and a spiral groove formed in the outer peripheral surface of said main shaft, said two chambers communicating with each other through said spiral groove when said carburetor butterfly valve is being closed, the movement of said main shaft being retarded by restricting the flow rate of said fluid through said spiral groove from one chamber to the other.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |