US3674043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preventing vapor lock during engine operation and of fuel leakage to carburetor after engine stoppage
Assignee: Individual
•
Filing: 1970-06-26
•
Granted: 1972-07-04
•
Expires: 1990-06-26
Abstract
Abstract Vapor lock which might otherwise occur in its fuel supply pump during high temperature operation of a liquid-fuel engine, is minimized or eliminated by continuously withdrawing a small fraction of the flow liquid from the bottom level of the pump outlet conduit and reintroducing it at the top level of the pump inlet conduit. Also, after pump and engine stoppage, pressurized liquid remaining in the pump to carburetor (outlet) conduit, is prevented from dribbling into the carburetor and vaporizing into adjacent space (and creating a fire hazard and air pollution) by relieving the back-pressure in such conduit and then closing same without breaking the liquid column, by valve means in the (sigmoid) pump bypass. Such small capacity bypass may be left open during pump and engine function, without interfering with normal operation, and closes in response to decreased backpressure in the line when the pump stops.
Inventors
- 👤 Neil C Norton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:18
CPC Classifications
F; F02; F02D; F02D33/00; F02D33/003; F02D33/006; F02M; F02M37/00; F02M37/0011; F02M37/0023; F02M37/0047; F02M37/20; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0324; Y10T137/0379; Y10T137/8593; Y10T137/85954; Y10T137/85978; Y10T137/86171
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
In a method of moving a liquid-fuel supply from a liquid-fuel reservoir by a pump inlet stream and pumping the fuel to a carburetor of an engine by a pump outlet stream so as to move liquid fuel to the carburetor from the reservoir at a normal operating pressure of the pump, the steps for restraining fuel entrance to the carburetor from the pump outlet stream after pump stoppage, comprising: back-relieving substantially all pressure in the outlet stream by reverse movement of a small stream of the liquid fuel having a very small cross-sectional flow area in respect to an internal cross section of the outlet stream so as to bypass the pump after cessation of pump operation until the pressure in said outlet stream is substantially equalized with the pressure in said inlet stream, and then stopping said reverse movement in response to decline of backpressure in said outlet stream so as to retain unpressurized liquid which was in the outlet stream from draining into the carburetor after the pump has stopped.
Claim 2
Dependent Claim
173 words
In a method of moving a liquid-fuel supply from a liquid-fuel reservoir by a pump inlet stream and pumping the fuel to a carburetor of an engine by a pump outlet stream so as to move liquid fuel to the carburetor from the reservoir at a normal operating pressure of the pump, the steps for restraining fuel entrance to the carburetor from the pump outlet stream after pump stoppage, comprising: back-relieving substantially all pressure in the outlet stream by reverse movement of a small stream of the liquid fuel having a very small cross-sectional flow area in respect to an internal cross section of the outlet stream so as to bypass the pump after cessation of pump operation until the pressure in said outlet stream is substantially equalized with the pressure in said inlet stream, and then stopping said reverse movement in response to decline of backpressure in said outlet stream so as to retain unpressurized liquid which was in the outlet stream from draining into the carburetor after the pump has stopped.
Claim 3
Dependent Claim
44 words
The method of the preceding claim 1 wherein continuously during pump operation said small stream is enabled to move to a top level of the inlet stream from a bottom level of the outlet stream, thereby minimizing occurrance of vapor lock in said pump.
Claim 4
Dependent Claim
133 words
In a method of moving a liquid-fuel supply from a liquid-fuel reservoir by a pump inlet stream and pumping the fuel to a carburetor of an engine by a pump outlet stream so as to move liquid fuel to the carburetor from the reservoir at a normal operating pressure of the pump, the improved step comprising: relieving potential or actual fuel vaporization in the pump or outlet stream by continually passing a small stream of the liquid fuel from a bottom level of the outlet stream to a top level of the inlet stream thereby reverse bypassing the pump and enabling purging of vapor formed therein so as to maintain a continuous supply of liquid fuel to the carburetor and prevent severance of such supply by occurrance of vapor lock in the pump.
Claim 5
Dependent Claim
133 words
In a method of moving a liquid-fuel supply from a liquid-fuel reservoir by a pump inlet stream and pumping the fuel to a carburetor of an engine by a pump outlet stream so as to move liquid fuel to the carburetor from the reservoir at a normal operating pressure of the pump, the improved step comprising: relieving potential or actual fuel vaporization in the pump or outlet stream by continually passing a small stream of the liquid fuel from a bottom level of the outlet stream to a top level of the inlet stream thereby reverse bypassing the pump and enabling purging of vapor formed therein so as to maintain a continuous supply of liquid fuel to the carburetor and prevent severance of such supply by occurrance of vapor lock in the pump.
Claim 6
Dependent Claim
38 words
The method of the preceding claim 3 wherein said small stream of bypassing liquid fuel enters the pump inlet stream by a downwardly concave segment of a sigmoid path arising from the bottom level of the outlet stream.
Claim 7
Dependent Claim
53 words
The method of the preceding claim 3 wherein upon pump stoppage, flow of said small stream of bypassing liquid fuel is stopped in response to decline of backpressure of the pump outlet stream, thereby preventing pump-pressurized liquid which was in the outlet stream from draining into the carburetor after the pump has stopped.
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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |