US1933753A

US1933753A - Fuel supply system and valve therefor

Info

Publication number: US1933753A
Application number: US584087A
Authority: US
Inventors: Clyde A Parsons
Original assignee: McCord Radiator and Manufacturing Co
Current assignee: McCord Radiator and Manufacturing Co
Priority date: 1931-12-31
Filing date: 1931-12-31
Publication date: 1933-11-07
Anticipated expiration: 1950-11-07

Description

c. A. PARSONS 41,933,753

FUEL SUPPLY SYSTEM AND VALVE THEREFOR Nov. 7, 1933.

Filed Dec. 31, 1931 2 Sheets-Sheet 1 IN VEN TOR.

V 'YW W,

ATTORNEYS 1933- c. A. PARSONS FUEL SUPPLY SYSTEM AND VALVE THEREFOR Filed Dec. 31, 1931 2 Sheets-Sheet 2 fa... {I 1w w W W M M W? A TTORNEYS Patented Nov. 7, 1933 UNITED STATES PATENT OFFICE FUEL SUPPLY SYSTEM AND VALVE THEREFOR Application December 31, 1931 Serial No. 584,087

9 Claims.

This invention relates to a force feed fuel supplying system for motor vehicles and a by-pass valve therefor.

The main object of the invention is to provide in a system of this character valve means whereby the pump will be able to supply fuel to the carbureter from the supply tank on the vehicle at a substantiallypre-determined and constant pressure regardless of the positive or negative 10 head to which the system is subjected as the supply tank is raised or lowered by the vehicle above or below the carbureter in the travel of the vehicle over a roadway. By this arrangement, the system will not siphon through the return or by-pass line to de-prime the pump when the-vehicle is ascending a grade nor will the carbureter be flooded when vehicle is descending a grade. In

either case, the pump will function properly to supply fuel to the carbureter at the pressure de- 0 sired regardless of the position of the supply tank above or below the carbureter except for the time the positive head on the system from an elevated tank becomes greater than that for which the valve is set. The system and valve means of my invention are especially adaptable to motor trucks, buses and the like, where the fuel tank at the rear of the vehicle is usually at a considerable distance from the carbureter at the front of the vehicle by reason of the long length of vehicles of this character. Due to the distance apart of these devices, a considerable positive or negative head is created on the system when the vehicle is descending or ascending a relatively steep grade by reason of the distance that the supply tank is lowered or raised by the vehicle with respect to the carbureter. With my invention these head conditions do not aifect the operation of the pump and the latter supplies fuel to the carbureter at a substantially pre-determined pressure at all times.

In carrying out the objects of my invention, the valve device in the return line of the system is so constructed and designed that it may be set to determine the pressure at which the pump delivers fuel to the carbureter from the supply tank. A negative head on the system by the lowering of the supply tank will not open the valve and thus the system cannot siphon back to the tank. A positive head on the valve as produced by raising the tank will not open the valve except when the elevation of the tank is to such a point as to create a positive head in excess of pressure for which the valve .is set. Under this condition, which is usually the extreme, the pump is required to pump against whatever pressure is at the rear of the vehicle.

developed by the positive head when it that at which the valve is set.

In the accompanying drawings:-

Fig. 1 is a diagrammatic view showing a system of the character referred to equipped with a valve device of my invention;

Fig. 2 is a similar view showing the system in reversely inclined positions to be hereinafter described;

Fig. 3 is a vertical sectional view of the valve 5 device; and I Fig. 4 is an elevational view of the same.

In the drawings, 1 indicates the fuel supply tank 2 indicates the carbureter at the front of the vehicle. 3 indicates the intake manifold connected with the carbureter as in assemblies of this character. 4 indicates a force pump, as of the rotary type, driven from the vehicle engine, and connected with the tank and carbureter, respectively, for supplying fuel to the latter from the tank at a predetermined positive pressure, as for example, four pounds. A pipe line 5 connects the tank with the pump on its intake side, while a pipe line 6 connects the carbureter with the pump on its discharge side, as shown in Figs. 1 and 2. A bypass or return line 7 connects the pump on its discharge side with the tank through a T-fitting 8 joining pipe lines 6 and 7, as shown. A strainer 9 is in the supply line 5. A valve device 10 of my invention is in the return line 7.

Valve device 10, as shown in Figs. 3 and 4, comprises a casing 11 made with its opposite ends open and closed by screw caps 12, 13. These caps clamp flexible diaphragms 14, 15 in the casing on seats provided therefor at the sides of the a casing. Gaskets may be employed at the edges of the diaphragms to prevent leakage past the same. The diaphragms extend across the casing in opposed relation and the space between the diaphragms is divided into two chambers 16, 17, one for each diaphragm, by a partition structure arranged within the casing. This partition structure comprises

horizontal webs

18, 19, one adjacent each diaphragm and a vertical web 20 extending between the horizontal webs and forming therewith seats for valve members 21, 22 carried by the respective diaphragms on the inner sides of .the same. The valve members 21, 22 are secured to their respective diaphragms by fastenit) exceeds ing members 23, 24, which may be in the form of screws engaged with nuts 25, 26 on the outer sides of the diaphragms. The nuts are of such size and shape as to support coiled springs 27, 28,

one for each diaphragm and lying between the 15 on the outer sides of the diaphragms to the atmosphere. The caps have threaded elements 12 13' by means of which the tension of the springs '27, 28 may be adjusted to hold the valves 21, 22 closed at the same or substantially the same pressure as required by my invention. The elements 12 13 are preferably in the form of screws extending into the caps through their end walls and engaging discs or plates 12 13 forming movable abutments for the outer ends of the adjacent springs 27, 28. Each screw has its outer end so formed that it may be engaged for turning, and a lock nut 12, 13 is provided for holding the screw in its adjusted position.

In accordance with my invention, and as shown in Fig. 3, the valve device is so made that the areas of the diaphragms 14, 15 as exposed to their respective chambers 16, 17 are exactly the same, and the same is true of the valve members 21, 22. In short, the diaphragms and their respective parts are duplicates ofeach other, so

that the valve device is a balanced one regardless as connected with the discharge side of the pump,

and the chamber 1'7 as connected with the tank 1.

The pressure at which the pump 4 delivers fuel to the carbureter from the tank 1 will depend on the pressure at which the springs 27, 28 are set to close their valves 21, 22. Under ordinary conditions, these springs are set to exert a four pound pressure on their valves, and the pump 4 will deliver fuel at this pressure to the carbureter in the operation of the system. In case an excess pressure is created by the pump, such pressure will act through chamber 16 on diaphragm 15 and open valve 22, thus relieving the pressure through chamber -17 and return line 7. Although valve member 21 of the other diaphragm 14 is subjected to this excess pressure in chamber 16, said valve will not be opened due to the larger pressure. area presented by diaphragm 15. I

The delivery of the pump 4 to the carbureter 2 at a predetermined pressure is in no way affected when the vehicle equipped with the herein described fuel supply system is traveling or standing on a level or substantially level roadway. At this time, the parts of the system occupy the positions shown in Fig. 1. It is only when the vehicle ascends or descends a grade, and more particularly a relatively steep grade, that the discharge of the pump at a predetermined pressure would be affected, if it were not for the use in the return line :7 of the valve device 10 of my invention. 1

When the vehicle ascends a steep grade, the parts of the system occupy the positions shown in full lines in Fig. 2. Under this situation the tank 1 is lowered considerably below the carbureter and presents a condition for the pump to siphon back to the tank 1 through the return line '7. This, however, is prevented by the valve device 10, due to the fact that both valves 21, 22;

are held by their springs against their seats, and the portion of the return line 7 connected with the discharge side of the pump is closed to the portion connected to the tank 1. As valve 22 will not open except under an excess of pressure at which the pump discharges to the carbureter, the pump will maintain that pressure regardless of the lowering of the tank 1 below the carbureter. The negative head so provided by lowering the tank will not open valve 21, and when valve 22 is opened by excess pressure created by the pump, the system will not siphon back to the tank.

When the vehicle is descending a grade, the parts of the system assume the positions shown in dot and dash lines in Fig. 2. At this time the tank 1 is raised above the carbureter andcreates apositive head against diaphragm 14 through chamber 17. If this head is in excess of the closing pressure of the spring on the diaphragm, the latter W21 be raised and valve 21 will open admitting t e pressure into chamber 16 and opening valve 22. As the pressure surfaces of both diaphragms are equal, the pressure of the positive head thereon will be equalized, and the pump will be required merely to pump against this excess pressure. Under the most extreme conditions of road grade and distance of the tank 1 from the carbureter 2, this is not excessive, and with my valve device in the return line, flooding of the carbureter is prevented when the tank is elevated to create a positive head on the system in excess of that for which the valves are set.

With the valve device of my invention incorporated in the return line of the system, the pump will have its full suction qualities and capacities at all times and will be able to maintain a substantially predetermined and constant pressure on its discharge side, regardless of the change in elevation of the supply tank 1 by the vehicle with respect to the carbureter as the vehicle travels, over a roadway. In thedrawings, the supply tank 1 is shown relatively small in diameter as compared to the pump 4 and other elements of the system. This-is made necessary by reason of the small scale of the diagrammatic views of Figs. 1 and 2. In practice the tank 2 is relatively large so as to hold the required amount of fuel for the engine with which the system is used.

The details of construction and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of my invention, except as pointed' out in the appended claims.

I claim as my invention;

1. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a carbureter arranged on the vehicle adjacent the opposite ends of the same, a pump connected on its intake side with the tank for drawing fuel therefrom and on its discharge side with the carbureter for supply fuel thereto, a return line connecting the discharge side of the pump with the tank for by-passing fuel about the carbureter, and valve means in the return line causing the pump to deliver fuel to the carbureter at a pre-determined pressure regardless of the change in position of the tank by the; vehicle above or below the carbureter in the travel of the vehicle'over. a roadway.

2. In a force feed fuel supplying system for motor vehicles, afuel supply tank and a carbureter arranged on the vehicle adjacent the opposite ends of the same, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, a return line connecting the discharge side of the pump with the tank for by-passing fuel about the carbureter, and valve means in the return line causing the pump to deliver fuel to the carbureter at a predetermined pressure regardless of the head produced on the valve means from the tank in the raising or lowering of the same by the vehicle above or below the carbureter in the travel of the vehicle over a roadway.

3. In a force feed supplying system for motor vehicles, a fuel supply tank and a carbureter arranged on the vehicle adjacent the opposite ends of the same, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, a return line connecting the discharge side of the pump with the supply tank for by-passing fuel about the carbureter, andvalve means in the return line causing the pump to deliver fuel to the carbureter at a pre-determined pressure whether the vehicle is on a level roadway or ascending or descending a grade.

4. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a carbureter, a'pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, a return line connecting motor vehicles, a fuel supply tank and a carbureter, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, a return line connecting the discharge side of the pump with the tank for by-passing fuel about the carbureter,

and avalve device in the return line, said valve device having valves and movable pressure receiving members for normally closing the valves, one member being subject to the pressure created by the pump for controlling the pressure at which the pump delivers fuel to the carbureter, and the other member being subject to the pressure condition in the return line between the valve device and the tank, said members having substantially equal areas exposed to their respective pressures.

6. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a carbureter, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, and a valve device for controlling the by-passing of fuel from the pump to the tank about the carbureter, said valve device having two chambers, one connected with the discharge side of the pump and the other connected with the tank, a pair of ports connecting said chambers, and a valve member and a flexible diaphragm therefor in each chamber for normally holding the valve member in close relation to its associated port.

7. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a carbureter, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, and a, valve device for controlling the by-passing of fuel from the pump to the tank about the carbureter, said valve device having two chambers, oneconnected with the discharge side of the pump and the other connected with the tank, a pair of ports connecting said chambers, a valve member and a flexible diaphragm therefor in each chamber, and pressure means acting on the diaphragms for normally closing the valve members against their respective ports.

8. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a'carbureter, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto,- and a valve device for controlling the by-passing of fuel from'the pump to the tank about the carbureter, said valve device having a casing provided with two chambers, one being connected with the discharge side of the pump and the other connected with the tank,

a pair of ports connecting said chambers, a valve member and a flexible diaphragm therefor in each chamber, spring means acting on the diaphragms for normally closing the valve members against their respective ports, and means for adjusting the tension of the springs.

9. In a force feed fuel supplying system for motor vehicles, a fuel supply tank and a carbureter, a pump having its intake side connected with the tank for drawing fuel therefrom and its discharge side connected with the carbureter for supplying fuel thereto, and a valve device for controlling the by-passing of fuel from the pump to the tank about the carbureter, said valve device having two chambers, one connected with the discharge side of the pump, and the other connected with the tank, a pair of ports connecting said chambers, and a valve member and a movable pressure receiving element therefor in each chamber for normally closing the valve member against its associated port, the valve members and pressure elements presenting differential pressure areas to the pressures created in the respective chambers.

CLYDE A. PARSONS.