US2821972A - System for emptying a plurality of tanks and shuttle valve therefor - Google Patents

Description

Feb. 4, 1958 o. H. BANKER 2,821,972

SYSTEM FOR EMPTYING A PLURALITY OF TANKS AND SHUTTLE VALVE THEREFOR Filed Jan. 5, 1956 IN VEN TOR. O5car-H.Barz/ 'er DISTRIBUTOR FIGQ Z United States Patent F SYSTEM FOR EMPTYING A PLURALITY OF TANKS AND SHUTTLE VALVE THEREFOR Oscar H. Banker, Evanston, Ill., assignor to New Products Corporation, Skokie, Ill., a corporation of Delaware Application January 5, 1956, Serial No. 557,510

7 Claims. (Cl. 123-127) This invention relates to a system for emptying a plurality of tanks or containers of fluid, and to a shuttle valve used therewith. For purposes of illustration this invention will be described with reference to its application to a multi-tank fuel system for an internal combustion engine such as may be used on an automotive truck, but it is understood that it is not limited to such application and may be used wherever it is necessary or desirable to use a plurality of tanks for a single fluid-utilizing mechanism.

It is known that trucks, busses and other large users of liquid fuel may be equipped with two or more fuel tanks, with appropriate valve means, manually controlled, for switching from one tank to another to keep the carburetor or other fuel feeding mechanism of the truck engine supplied with the liquid fuel. It has been customary to provide the internal combustion engine of the truck, bus, etc. with a fuel pump located at, and driven by, the engine for drawing the fuel from a selected tank and pumping it to the carburetor of the engine. Where volatile fuels are used, such fuel may vaporize at, or before reaching, the pump, and due to the inefficiency of the pumps usually furnished with such engines, the vapor then prevents the pump from creating the requisite suction pressure to keep the fuel moving from the tank to the engine, thus creating the condition known as a vapor lock. To obviate the vapor locking conditions, it has been proposed to submerge the fuel pump in the tank itself so that it is always primed and thus in a condition to continue supplying fuel at a predetermined pressure to the engine as long as there is fuel in the tank. When one tank is emptied, the pump in another tank filled with fuel is then switched on to continue the supply of fuel to the engine.

Since two or more tanks are usually connected to one carburetor or other fuel feeding device, it has been proposed to install valves in the lines from the tanks to permit the selection of the tank which shall be effective, and to prevent the fuel being pumped into an empty tank instead of to the carburetor. These selector valves are usually solenoid operated and hence costly.

It is among the objects of this invention to provide a multi-tank fuel feeding system for an internal combustion engine in which the possibility of the creation of a vapor lock condition is substantially eliminated, the system being particularly characterized by the use of simple and inexpensive controls for changing from one tank to another as the immediate source of fuel.

As a more specific object, this invention seeks to provide a system for supplying fuel to the carburetor of an engine, which system utilizes two or more tanks, each equipped with a submerged pump controlled from the exterior of the tank, and with automatically operable means for opening the line to the carburetor from the pump which is effective and closing all lines from the other pumps.

- A specific object of this invention is to provide a simple shuttle valve for use in a multi-tank fuel feeding system, said shuttle valve being automatically biased by the fluid under pressure developed by the fuel feeding pump then in operation to open theline fr m said pressurized fuel r 2,821,972 1 Patented Feb. 4, 1958 to the carburetor of the engine associated therewith, and closing the line to the second tank or source of fluid to prevent escape of the pressurized fuel to the said second source.

Another condition which has been found harmful in internal combustion engines is the formation of varnish in the carburetor of an engine when the engine is not used for relatively long periods of time. In the trucking industry, for example, it is frequently necessary to store a truck tractor for a month or more, and after such storage it has been found that the deposit of varnish is so thick as to render substantially impossible the passage of fuel through the fuel lines and carburetor to the engine. The formation of this varnish is the result of the continued presence of a fixed quantity of the gasoline or other fuel in the carburetor.

This invention accordingly has within its purview the additional object of providing means for draining the carburetor of an engine and the fuel lines leading thereto the instant the puel pump ceases to operate so that the formation of varnish or sludge is substantially prevented.

These and other objects of this invention will become apparent from the following detailed description when taken together with the accompanying drawings in which:

Fig. l is a schematic diagram of a system of supplying fuel to a carburetor from any one of a plurality of tanks, the system incorporating the features of this invention;

Fig. 2 is a cross section through a shuttle valve used in the system of Fig. 1; and

Fig. 3 is a side elevational view of the shuttle valve of Fig. 2.

The system shown in Fig. 1 is adapted for use with a carburetor shown generally at 10 which includes a bowl 11, a throat 12 in which is disposed a butterfly valve (not shown) controlled in turn by a lever 13 connected through links 14, 15, 16 and 17 to an accelerator pedal 18 pivotally mounted on the toe board 19 of a truck, bus or other automotive vehicle. Fuel enters bowl 11 through a pipe 20 which in turn is connected through suitable pipes 21, 22, 23 and 24 to individual fuel supply tanks 25, 26 and 27. It may be noted that pipes 22 and 23 are connected to pipe 24 through a shuttle valve 28, and pipes 21 and 24 are connected to pipe 20 through a similar shuttle valve 29. Said shuttle valves 28 and 29 are shown in Fig. 1 schematically and will be described in detail in connection with the description of Figs. 2 and 3.

Tanks 25, 26 and 27 may be any tanks with which an automotive vehicle such as a truck, bus or the like may be equipped, either at the factory, or by the addition of tanks to the factory equipment made by the purchaser or, operator of the vehicle. It is understood that any number of such tanks may be used in the present system and' connected successively in pairs to shuttle valves in the manner shown in connection with tanks 26 and 27.

It is contemplated that each tank 25, 26 and 27 will be equipped with a submersible motor-driven pump of known construction and shown in dotted outlines at 30,

31 and 32. Each such submersible pump unit includes a pump 33 and an electric motor 34, the latter being appropriately sealed to enable it to operate when submerged in the fuel. Each motor has a ground connection such as 35 and a connection 36, 37 and 38 respectively, leading to individual single-pole single- throw switches 39, 40

and 41 connecting the motors in units 30, 31 and 32 to a I that when ignition switch 43 is on to connect line 42,

- to battery 44, the motors for the units 30, 31 and 32 may be individually'controlled by their respective switches 39, 40 and 41. Since each switch 39, 40 and 41 is independent of the other it may be possible to have two or more switches on at the same time so that more than one unit is in operation; This multiple operation of the units is not in any way harmful to the system as will be explained hereinafter and makes possible a smooth and continuous flow of fuel to the carburetor during a changeover from one tank to another.

The shuttle valves 28 and 29 may be identical in construction and one such valve is shown in enlarged section in Fig. 2. In that figure it may be observed that the valve is comprised of a valve body 47 having a central chamber 48, preferably of circular cross section for ease of manufacture, a side opening 49 connected at its inner end with the central portion ofchamber 48, and aligned inlet openings 50 and 51. Said aligned openings 50 and 51 may be the central bores of fittings suitably secured to valve body 47 and having appropriate means for adapting them for connection to the pipes leading to the valve. Opening 49 may likewise be the central bore of a fitting provided with appropriate known means for attachment to an outlet pipe.

Adjacent each inlet opening 50 and 51 is a counterbore 52 and 53, respectively, in which are axially slidable the ends 54 and 55 of the shuttle valve 56. Said ends 54 and 55 may be identical in construction and may be formed with recesses 57, 58 respectively having cross bores 59 and 60 connecting the recesses with peripheral grooves 61 and 62, respectively. The shoulder formed between the counterbores 52, 53 and the cylindrical wall of chamber 48 are preferably made frusto-conical as shown in 63 and 64 so that they function as valve seats for valve 56. The corresponding contacting portion of the valve 56 is comprised of spaced O-rings of known construction, that is, endless rings having a circular radial cross section and compounded of an elastomer having characteristics which enable it to remain in contact with the fluid being pumped for long periods of time without any deleterious etiect on the rings. Each said O-ring 65 and 66 is retained in a peripheral groove 67, 68 respectively, the adjacent walls of which are of somewhat greater diameter than the remote or outer walls so that the O-ring is compressed between the frusto- conical wall 63 or 64 and the body of the valve 56 to form a fluid tight seal therebetween when the valve is urged by fluid under pressure against one or the other of said frusto-conical surfaces.

It may be observed that the central portion of valve 56 is formed with a wide and relatively deep groove 69, the function of which is to provide an unrestricted path for the fluid issuing from the openings 59 and 60 farthest removed from side opening 49 around the valve to said side opening. It has been found that without such groove, the flow through the shuttle valve is materially reduced and any effort to relieve the situation by redesigning the housing results in a much more expensive housing.

The axial spacing between said frusto- conical surfaces 63 and 64 is so related with respect to the axial spacing of the grooves 61, 62 that when the valve is in either one of its extreme positions, that is, extreme left-hand or extreme right-hand positions as viewed in Fig. 2, one of the grooves will be sealed and the other will be opened to chamber 48. The axial spacing between the grooves 61 and 62, however, is such that when the valve 56 occupies a central position wherein the O-rings are substantially equally spaced from their respective seats 63 and 64, both grooves 61 and 62 will be in communication with chamber 48. This latter condition will obtain for slight variations from a central position so that the valve need not be located accurately in order to cause grooves 61 and 62 to communicate with chamber 48.

In operation, assuming that valve body 47 is that of valve 28, and that inlet opening 50 is connected to pipe .75

22, inlet opening 51 is connected to pipe 23, and outlet opening 49 is connected to pipe 24, and assuming further that ignition switch 43 is on and switch 41 has likewise been operated so as to cause pump unit 32 to be operative while switches 39 and 40 are inoperative, pump unit 32 will supply fluid from tank 27 to pipe 23 at a predetermined pressure which may be that normally produced by a fuel pump. Said fluid under pressure, therefore, will enter opening 51, counterbore 53 and recess 58 to exert a pressure upon valve 56 to move said valve to the left. Inasmuch as pump unit 31 is not operative at that time there is no fluid under pressure in pipe 22 and hence valve 56 will be subjected to a differential pressure in favor of moving said valve to the left. It will therefore assume the position shown in Fig. 2 wherein O-ring is pressed against frusto-conical surface 63 to seal chamber 48 with respect to inlet opening 50. Fluid from inlet opening 51 will pass through the cross-bores 60 into peripheral groove 62 and thence outwardly into chamber 48, outlet opening 49 and pipe 24.

When tank 27 is almost empty, switch 40 controlling pumping unit 31 may be turned on while switch 41 is still on until pumping unit 31 becomes operative. Under this condition fluid under substantially the same pressure as that of the fluid in pipe 23 will be present in pipe 22 to subject opposite sides of valve 56 to substantially the same pressure. Momentarily, however, while chamber 48 is closed to inlet 50 as shown in Fig. 2, the pressure in pipe 22 may build up to a value slightly higher than that in pipe 23 so that there is a pressure differential on valve 56 tending to move it to the right as viewed in Fig. 2. Just as soon as such movement is effected sufliciently to permit the fluid under pressure in recess 57 to pass outwardly through cross-bores 59 and peripheral groove 61 into chamber 48, the pressure in pipe 22 will drop to substantially the same value as that in pipe 23, thereby allowing fluid to fiow from both inlet openings 51 and 50 through the valve 56 into chamber 48 and out through outlet opening 49 into pipe 24. After a short interval, and preferably after a positive indication from a suitable liquid level gage associated with tank 27 (not shown) that tank 27 is empty, switch 41 may be opened to shut off pumping unit 32. If the absence of fuel under pressure in pipe 23 has not already done so, the shutting down of pump unit 32 will cause a pressure drop in inlet opening 51 to substantially zero, whereupon a pressure differential will be established across valve 56 in favor of moving said valve to the right as shown in Fig. 2 under the influence of the pressure in inlet opening 50, and said valve will accordingly move in that direction until O-ring 66 seats against frusto-conical valve seat 64, thereby closing chamber 48 to inlet opening 51 while opening said chamber fully to pcripheral groove 61. Tank 26 thus will be supplying the fuel to pipe 24 while pipe 23 is closed.

Assuming now that shuttle valve 29 is of substantially the same construction as the one shown in Fig. 2, it may be observed that pipe 24 bears the same relation to valve 29 as pipe 23 bears to valve 28 and pipe 21 bears the same relation to valve 29 as pipe 22 bears to valve 28, so that valve 29 Will be in substantially the conditions shown in Fig. 2 while tank 26 is being emptied, assuming, of course, that pumping unit 33 is inoperative. When it appears that tank 26 is about to be emptied, switch 39 may be turned on to start pumping unit 33 in operation, whereupon fluid under pressure will enter pipe 21 and tend to push the valve 56 of shuttle valve 29 to the right to open pipe 21 to pipe 20. Upon the creation of a suitable pressure drop in pipe 24 due to the emptying of tank 26, or the cessation of operation of unit 31, valve 29 will shut off communication between pipes 24 and 20, and will then open communication fully between pipes '21 and 20.

It may be observed that by following the pattern shown in Fig. 1', any number of tanks'equipped with individual pumps may be serially connected and operated by individual switches to provide a continuous supply of fuel to carburetor 10. It may also be observed that it is immaterial which tank is operated first, since the operation of the pumping unit in any one tank will supply fluid under pressure in the pipe leading from the tank to the first shuttle valve in the line, whereupon that valve will adjust itself to open the line to the next shuttle valve, and that, in turn, will open the line to the third and so on until a continuous line to the carburetor is open and the lines to all other tanks will be closed.

When the ignition switch 43 is opened to interrupt the flow of energy from battery 44, the engine associated with carburetor it) (not shown) as well as the pumping units 341), 31 and 32 will cease operating, and hence there will be no pressure on either side of any of the valves 2%, 29, etc. It is impossible, however, for any of the valves to assume a position in which connection is not established from at least one inlet opening to the central chamber 48, and hence any fluid in bowl 11 will drain automatically back to one or another of the tanks in the system. This, of course, presupposes that the bowl 11 is at an elevated position with respect to all of the pipes and that said pipes and valves and tanks are so arranged as to promote draining by gravity into at least one of the tanks.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention is not to be limited thereto but is to be determined by the appended claims.

I claim:

1. A system for supplying liquid to an engine including a container at the engine, a plurality of supply tanks containing the liquid, individual pump means for each tank, individual means for driving each pump, means for selectively operating the driving means, a pipe establishing a passageway to the container, a shuttle valve having an outlet port connected to the pipe and an inlet port connected to the output of one of said pumps, a second inlet port on the shuttle valve, and means connecting the output of the pump for another of the tanks to the second inlet port, said shuttle valve including means responsive to difierence in pressure of the fluid in the inlet ports to open the inlet port from a tank having the greatest pressure.

2. A system as described in claim 1, said container being elevated above the tanks and said valve, pipe and connecting means being disposed to drain the container by gravity in the absence of fluid under pressure in the first and second inlet ports.

3. A system for supplying liquid to an engine including a container at the engine, first, second and third liquid supply tanks, individual means for pumping the liquid from each tank, a shuttle valve having an inlet port connected to the output of the pumping means for the first tank, an inlet port connected to the output of the second tank and an outlet port, a second shuttle valve, said second shuttle valve having an inlet port connected to the output 60 of the third tank and an inlet port connected to the outlet port of the first shuttle valve and an outlet port connected to the container.

4. A system as described 221 claim 3, and means for selectively operating one or more pumping means, the shuttle valves being adapted to close the inlet port connected to a pumping means which is inoperative.

5. A system as described in claim 3, each shuttle valve being adapted to assume a position wherein one or the other of the inlet ports is open, and said container being disposed at the highest level of the system, such that the fluid wiil drain by gravity from the container upon cessation of operation of all of the pumping means.

6. A system for supplying liquid fuel to the carburetor of an engine having an ignition system for the engine including a source of electrical energy and an ignition switch having off and on positions, first and second fuel tanks, a submerged pump in each tank, individual electrically operated means for driving each pump, individual switch means for controlling the operation of the pump driving means, each said individual switch means being in series with the ignition switch and the source of electrical energy such that all of the pump driving means are rendered inoperative when the ignition switch is in its off position, a shuttle valve having a pair of inlet openings and an outlet opening, and pipes connecting each inlet opening with the input of a pump and the outlet opening with the carburetor, said shuttle valve having means for establishing communication between the outlet opening and at least one inlet opening when all of the pump driving means are rendered inoperative whereby to drain the carburetor and the pipes through said valve.

7. A shuttle valve comprising a valve body having spaced inlet openings, a side outlet opening, a central chamber in communication with the side outlet opening,

spaced chambers in communication one with each inlet opening and with the central chamber, and a valve having a central body portion and reduced end portions contacting the walls of the said spaced chambers and serving to guide the valve in the block, said central body portion having a peripheral groove therearound to promote unrestricted flow of fluid around the said body portion, sealing means on either side of the central body portion, valve seats in the body adapted to be contacted by the sealing means to effect a seal therebetween, said end portions having passageways connecting the spaced chambers and the exterior of the end portions between the sealing means and the end of the valve adjacent thereto, said exterior of at least one end section being exposed to the central chamber at any position of the valve in the block, whereby to establish a passageway for the fluid through the valve regardless of the position of the valve and thus to adapt the valve to drainage of the outlet therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 2,693,812 Jones et a1 Nov. 9, 1954 2,758,579 Pinotti Aug. 14, 1956 FOREIGN PATENTS 882,423 France Mar. 1, 1943

Images