Automatic temperature and humidity regulation – Thermostatic – In fluid controlled
Reexamination Certificate
2000-12-20
2002-06-04
Tapolcai, William E. (Department: 3744)
Automatic temperature and humidity regulation
Thermostatic
In fluid controlled
C236S10100B
Reexamination Certificate
active
06398119
ABSTRACT:
TECHNICAL FIELD
This invention relates generally to dual temperature actuated valves, and more particularly to fuel systems utilizing dual temperature actuated valves.
BACKGROUND ART
One property of diesel fuel that can be altered by refining is the temperature at which paraffins will precipitate. The temperature at which this precipitation occurs is referred to as the “cloud point” of the fuel, and is often varied by distillers depending upon the geographic region in which the fuel is intended for use. For instance, fuel that is intended for use in colder climates will typically have a lower cloud point than fuel intended for use in warmer regions. Because it is undesirable to have paraffin precipitates clogging up fuel system components, fuel systems are often designed with a means to circulate warm fuel through the system as soon as possible after cold start. One method for dealing with this problem is the positioning of a temperature sensitive valve in the return line between the fuel injectors and the fuel tank. When the temperature of fuel flowing through the supply line is relatively low, the fuel is directed from the return line to the supply line to be recirculated through the fuel system to warm the relatively cold fuel. When the fuel temperature is relatively high, the fuel is directed back to the fuel tank. While these valves have performed adequately, there is still room for improvement.
For instance, a fuel transfer problem can occur when the fuel system is evacuated and the fuel lines become filled with cool gaseous vapors. If this occurs when the detected temperature in the supply line is relatively cold, the bypass valve will connect the fuel supply to the fuel return line, thus allowing the fuel pump to continue to circulate the vapors through the fuel system while preventing the pump from pulling fuel from the fuel tank to prime the system. In turn, the engine will be prevented from starting.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention, a dual temperature actuated valve includes a valve housing that defines a passageway extending between an inlet and an outlet. At least one valve member is movably positioned in the passageway. Positioned adjacent the inlet is a first temperature sensor. A second temperature sensor is positioned adjacent the outlet. The valve member(s) opens the passageway when a first temperature sensed by the first temperature sensor is greater than a first predetermined temperature and a second temperature sensed by the second temperature sensor is less than a second predetermined temperature. The valve member(s) closes the passageway when at least one of the first temperature is less than the first predetermined temperature and the second temperature is greater than the second predetermined temperature.
In another aspect of the present invention, a fuel system includes a fuel tank and at least one fuel injector. A supply line extends between an outlet of the fuel tank and an inlet of the fuel injector(s). A return line extends between an outlet of the fuel injector(s) and an inlet of the fuel tank. A bypass passageway extends between the supply line and the return line. Positioned in the bypass passageway is a valve. The valve is movable toward an open position when fluid in the return line is relatively warm and fluid in the supply line is relatively cold. The valve is movable toward a closed position when at least one of fluid in the return line is relatively cold and fluid in the supply line is relatively warm.
In yet another aspect of the present invention, a method of controlling a bypass passageway includes providing a bypass valve that is positioned in a passageway between a first line and a second line. The passageway is opened when fluid in the second line is relatively warm and fluid in the first line is relatively cold. The passageway is closed when at least one of fluid in the second line is relatively cold and fluid in the first line is relatively warm.
REFERENCES:
patent: 4299354 (1981-11-01), Ketley
patent: 4398662 (1983-08-01), Costello
patent: 4560104 (1985-12-01), Nagumo et al.
patent: 4674679 (1987-06-01), Saur
patent: 4744336 (1988-05-01), Miller
patent: 5215065 (1993-06-01), Snyder
patent: 5738276 (1998-04-01), Saur
patent: 5794598 (1998-08-01), Janik et al.
patent: 5799625 (1998-09-01), Ziolek et al.
patent: 5813601 (1998-09-01), Priest et al.
patent: 5826790 (1998-10-01), Raether et al.
patent: 6065682 (2000-05-01), Frunzetti
Duffer Bradly G.
Loer Daniel L.
Mueller Jeffrey J.
Ali Mohammad M
Caterpillar Inc.
Liell & McNeil
Tapolcai William E.
LandOfFree
Thermally controlled valve and fuel system using same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermally controlled valve and fuel system using same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermally controlled valve and fuel system using same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2895734