US1874249A - Liquid feeding device - Google Patents

Description

Aug, 30, 1932. R w DAVY 1,874,249

' LIQUID FEEDING DEVICE Filed Jan. 15, 1951 s Sheets-Sheet 1 gwumtoc v Rmhard 1D. Davy,

Aug. 30, 1932. R DAW 1,874,249

LIQUID FEEDING DEVICE Filed J n- 1931 5 Sheets-Sheet 2 Aug. 30, 1932. R. w. DAVY 1,374,249

LIQUID FEEDING DEVICE Filed Jan. 15, 1931 I5 Sheets-Sheet I5 damn,

mummy,

Patented Aug. 30, 1932 PATENT OFFICE RICHARD W. DAVY, OF'NEW YORK, N. 'Y.

. LIQUID FEEDING DEVICE Application filed January15, 1931.

My invention relates to a fuel feeding device for internal combustion engines by means of which fuel is drawn from a main supply tank usually located below the level of the carburetor, into a storage tank above the carburetor and delivered by gravity to the carburetor as required.

Heretofore, the better known makes of fuel feeding devices have been subject to mechanical defects which have seriously affected the operation of the devices. One of the commonest causes of failure. of the devices is leakage of the air inlet valve due to the rapidity with which said valve is moved by its operating mechanism. Another difficulty with these devices is the uncertainty of priming the vacuum tank thereof, should the main fuel tank be emptied and then refilled, as generally, there is sufficient leakage of the valves to prevent the vacuum from reachmg a value suificient to draw in the fuel, even though the motor make many revolutions. The common practice is to prime either the vacuum tank or the carburetor in order to avoid undue cranking.

" economic viewpoint is the method of manufacturing and assembling the device. All the parts of the device may be formed by such simple mechanical operations, as drawing, pressing and punching, since an appreciable variation in dimensions on most of the parts is permissible.

The specific embodiment of the device described herein to illustrate the principles of the invention includes a storage tank, a pumping chamber having means for automatically controlling the pumping of fuel from a main tank to the pumping chamber and means for controlling the flow of fuel from the pumping chamber to the storage tank. Various other objects and aspectsof Serial No. 509,001.

the invention will become apparent from a perusal of the following detailed description thereof, wherein reference is made to the accompanying drawings, in which:

Fig. 1 is an outline view of a motor car with the device and attendant parts shown thereon.

Fig. 2 is a plan view of the device.

Fig. 3 is an elevational view of the device.

Fig.4 is a sectional view taken along line 4-4: of Fig. 5. i

Fig. 5 is a vertical sectional view of the device with the parts in a pumping position.

Fig. 6 is a sectional view taken along line 6-6 of Fi 5, with parts of the foot valve broken away.. i

Fig. 7 is an enlarged fragmentary sectional view similar to Fig. 5 with the parts in a nonpumping position.

Fig. 8 is a sectional view taken on line 8-8 of Fig. 7 looking in the direction of the arrows. V

Fig. 9 is a fragmentary group perspective showing the cap in disassembled relation to the pumping chamber. 7

Referring to Fig. 1 of the drawings, there is shown in broken lines the outline of a motor vehicle 10 which includes an internal combustion engine (not shown) havingan intake manifold 11, a carburetor 12, an air cleaner 13 therefor, and a main fuel tank 14 which is at atmospheric pressure. The fuel feeding device 15 connected to the tank 14 by a tube 16 and to the carburetor 12 by a tube 17 receives its suction through a tube 18 connected into the manifold 11. The entire device 15 may be mounted to the dash, or any suitable place on the vehicle, above the liquid level in both the tank 14 and the carburetor 12 with the distance above the lowest liquid level not greater than the height of a liquid column that can be supported by the available source of vacuum. The, device may be mounted to a portion of the vehicle'19 as by a strap bracket 20 and suitable fastenings 21.

The fuel feeding device includes a storage tanker compartment of suitable size formed of atubular portion having its upper end fianged as at 26, a flanged closure 27 for said end is detachably secured thereto with an annular gasket 29 interposed between said parts, and a closure 31 for the lower end of tank which may be formed integrally therewith. The tubular portion 25 is further formed with circumferential ribs 30 which prevent the tank from slipping through its supporting bracket or brackets. lVhether formed integrally, or as shown, the lower closure 31 is formed with a depressed portion 32 which serves as a sediment sump.

An inlet tube 33 projects into the tank a considerable distance, being secured in a flanged opening 34 formed in the depressed portion 32 of the closure 31 and reinforced by a flanged collar 35. An outlet tube 36 projects into the tank a short distance being secured in a flanged opening 37 of the closure 31 and reinforced by a flanged collar 38. The purpose of projecting the tubes into the tank will appear later.

In the present form of the device a tubular pumping chamber 40 of less area than the storage tank is formed with an offset lower portion 41 having openings or valve ports 42 and a skirt or flange portion 43 which is secured in the depressed portion as by soldering. The offset portion 41 provides a serviceablevalve seat for a foot valve 44 which controls the flow of fuel from the pumping chamber into the storage tank. The valve 44 is shown as formed of a plurality of vegetable parchment rings surmounted by a metal washer heavy enough to insure positive valve action, but any thin flexible material which is not affected by the fuel may be used for the rings. The number of rings is to be determined by the physical properties of the substance used, however, a single washer of soft pliable material may be used as a valve,

providing its specific gravity int-he fuel is,

suflicient for proper action of the valve. It is also possible to use other valve arrangements between the pumping chamber and the tank as the showing is merely exemplary of the invention.

The closure 27 is formed with a shallow depressed portion 45 and a downwardly proj ecting collar 46 through which the pumping chamber 40 projects. with the pumping chamber permits air to seep between said parts into the storage tank so that the storage tank is supplied with atmospheric pressure. Besides providing an air vent for the storage tank the collar also serves as a baflie to prevent loss of fuel by surging or splashing. Since the liquid is in the form of an annular cylinder any motion imparted to it by a given movement of the tank is less than if the liquid were in the form of a plain cylinder. Such motion of the liquid as does occur, causes it to. flow around both sides of the pumping chamber and pile upat one side of the tank. If it rises high enough to reach the top of the tank, it is The fitof the collar I first deflected by the flange 26 then by the collar 46. As an added protection against leakage between the pumping chamber and collar, the depressed portion 45 may be provided with a flexible gasket 47 which closely fits the pumping chamber and prevents fuel from going further up the outside of the pumping chamber. The flexibility of the gasket and the relation of its inner edge to the rounded edge of the depression is such that should the pressure in the storage tank fall an appreciable amount, atmospheric pressure will tend to flex the gasket suiliciently to permit air to seep past the gasket until the pressure in the storage tank is restored.

The upper end of the pumping chamber is formed to receive a valve mechanism 48, a float container or chamber 55, a float 60 operatively mounted therein for actuating the valve mechanism, and a suction connection 76. In the present form of the device the valve mechanism 48 includes a closure plate 49 for the pumping chamber detachably secured to a flanged portion 50 of said chamber by screws 51. The closure plate 49 is formed with a cup-shapedportion 52 having an atmospheric port 53 at the lowest part thereof. The port is formed with a valve seat in which a ball valve 54 is normally seated by gravity. The float container 55 in the form of a tube of less cross-sectional area than the pumping chamber and, having the lower end 56 closed, is formed with an inwardly flanged enlarged upper portion 57 which is press fitted into the upper end of the pumping chamber 40 and is further supported as by the screws 51. Near the top and below the enlarged portion 57 of the float container 55 fuel inlet ports 58 are formed. Adjacent the end 56 of said container ports 59 are formed.

A float 60, preferably formed of copper to lessen the tendency towards fatigue and eventual failure as a result of flexing due to changes in pressure inside and outside of the float, is formed as with a tubular body 60 having separate top and bottom caps 61 and 62. The caps 61 and 62 are formed with external flanges 63 and 64 respectively which center and guide the float in the float container and prevent the thin metal walls the body 60 from rubbing against the container. The upper flange 63 being blank also serves as a baffle to prevent fuel from surging or splashing thereabove and getting into the vacuum connection. The top cap 61 is provided with a s1 .all cross hatched disc 65 which contacts with the ball valve 54 when the float is raised, preventing the The lower flange 64 should be perforated or serrated to permit maximum circulation of fuel past the flange without reducing its effective outside diameter (see Fig. 8).

Displacement of the ball valve 54 from the cup-shaped portion 52 accidentally or due to road shocks, is prevented by a cap 7 0 which has a depressed portion 71 so positioned with respect to the cup-shaped portion that the space between said portions 52 and 71 is less than the diameter of the ball valve. In the present form of the device the cap is formed with an external flange 72 and an inverted L-shaped slot 73 the short leg of which is provided with a notch 74. The slot 73 is sufficiently wide at all points so the cap may be attached and detached from the device without disturbing the vacuum connection 7 In attaching the cap to the device the slot is positioned opposite'the vacuum connection 76 and the cap moved downwardly until the flange 72 rests on the gasket 47. in this position the bottom of the short leg of the slot will be too high to pass under the vacuum connection 7 6 so the cap must he forced downwardly until said portion of the short leg is aligned with the bottom of the connection. Forcing the cap downwardly causes a flexing in the closure 27 so that when the cap is turned until the end of the short slot contacts with the vacuum connection 76 and the force is removed, the residual spring in closure 27 will cause the notch 74 to engage the vacuum connection and retain the affected parts in leak-proof relation. The slot '2 3 will admit air into the space between the cap and the pumping chamber and as before described into the storage tank. In order to prevent anyforeign matter entering the tank an air cleaner is provided as b securing a porous pad or fine mesh screen 75 of suitable size to the pumping chan'iber so that it will completely screen the slot 73 when the cap is in position. The vacuum connection 7 6 is provided with a restricted portion 77 for a purpose to be hereinafter described. Or, as indicated in broken lines in 1, a tube 78 may be connected to the carburetor intake back of the air cleaner 13 and to the cap 70 so that a supply of clean air will be available to maintain atmospheric pressure in the storge tank.

In practice it has been found that certain dimensional relations between the parts should be maintained to obtain a' iven resuit. For example, the area'of the annular space between the pumping chamber 40 and the float container 55 shouldbe equal to, or greater than, the cross sectional area of the inside of the inlet tube 33. The total area of the ports 58 in the float container 55 should be greater than either of the aforementioned areas. The combined area representing the space betwe n the float and float container and the openings 59 in the float container should also at least be equal to the efiective area of the inlet tube 33. A smaller area between the pumping chamber and the float container would cause restriction of liquid flow and consequent delay in operation of the device. 7 A smaller area between the float and float container would result in a portion of the liquid entering the ioat container being drawn into the vacuum connection by the suction thus disturbing operation of themotor.

The diameter of the ball valve 54 and the size of the float 60 are interdependent and are governed by mechanical conditions necessary to the proper operation of the device. The

size of the valve port 53 should be'such that not less than two thirds nor more than three quarters of the radius of the ball will pro ject below the lower edge of the port. An increase in the diameter of the ball to give a larger valve port would necessitate, a larger float, a larger float container and a larger pumping chamber which in .turn would reduce the capacity of the storage tank. A smaller ball, to give increased capacity without too large a storage tank, would not only necessitate a smaller valve port,but, dueto the decreased radius of the ball would decrease the height to which the ball could be lifted from its seat.

A primary factor in the control ofthe period of the cycle is the size of the ports 59 at the base of the float container. Their dimensions should be such that the interval of time between the lifting and reseating of the ball valve is approximately the same as the time required for the transfer of a maximum quantity of fuel from the pumping chamber to the storage tank when said tank is initially empty, or nearly so. An error in this dimension, however, will have no other effect in the operation of the device than to decrease the pumping capacity. Y The fuel inlet tube 33 should be extended well up into the pumping chamber, as close as practical to the bottom of the float container; This is to safeguard against the storage tank draining itself back into the main fuel supply tank should the foot valve prove to be not absolutely tight. Of the volume of liquid 'in the pumping chamber above the fuel inlet tube, a certain amount drains back down the tube at each cycle. This quantity is small, however, since the volume of the fuel above the top of the tube is small in comparison to the volume below the tube and since the cross sectional area of the inlet tube is small in comparison to the total area of the ports 42 of the foot valve. 7 i

- The fuel outlet tube 36 should be extended a short distance above the bottom of the storage tank to provide a sump in which sediment may be caught and prevented from passing into the carburetor supply line 17 and to provide a liquid seal for the foot valve; In the tighter against their seats.

event that the main fuel supply tank is exhausted and the storage tank is drained to the level of the outlet tube 36, the device may be made to function by simply filling the main supply tank and turning the motor over a few times with the throttle closed. If the liquid seal were not maintained, a bit of sediment on the valve seat might permit air to enter the pumping chamber as fast as it could be removed through the vacuum connection, thus rendering the device inoperative.

Operation With the device connected to the main fuel supply tank 14 and to the carburetor 12 and the intake manifold 11 substantially as shown in' Fig. 1 the device is ready to begin its cycle of operations. At this time the foot valve 441- will be closed, the float 60 will be resting on the bottom of the float container thereby permiting the ball valve 54 to seat itself. As the motor turns over a vacuum will be formed in the pumping chamber and will tend to pull the foot valve and the ball valve Said vacuum also tends to draw fuel from the main supply tank 14 into the pumping chamber 40. by way of the inlet tube 33. hen the liquid level of the fuel being drawn into the pumping chamber reaches the ports 59 in the bottom of the float container. a portion of the fuel will run through these openings tending to fill the container. Since the area of these ports is small in comparison to the area of the inlet tube and since the volumes to be filled inside and outside the float container are approximately the same, the liquid level of the fuel outside the float container will rise much quicker than the liquid level inside said container until the ports 58 in the container are reached. The total area of said ports being greater than the annular space between the pumping chamber and the fuel inlet tube 33 permits all the fuel rising around the container to flow through the ports into the container until the buoyancy of the float is suflicient to lift the ball valve from its seat. For the float to function, its buoyancy must exceed the weight of the ball, plus the force of the vacuum in the pumping chamber tending to keep the ball valve seated. Once the force of the vacuum is overcome the entire upward force of the float is exerted against the weight of the ball alone, as the air pressure on all surfaces of the ball becomes substantially equalized due to the air rushing in. This results in a prompt positive valve action. The float and ball continue to rise as a unit until the top of the float comes in contact with the under side of the valve seat. In this position by virtue of the cross hatched disc 65 practically all of the area of the valve opening is available to the free passage of air into the pumping chamber. Then, since the area of the vacuum connection 76, due tothe restriction 77, is less than the area of the valve port the pressure inside the pumping chamber will rapidly approach atmospheric. During this period, as the fuel rises in the pumping chamber, it will exert an increasing force, tending to lift the foot valve let from its seat, proportional to the increasing head of liquid in the pumping chamber. The forces tending to keep the foot valve closed are the weight of said valve plus the difference in pressures on opposite sides of the valve applied over the total area of the ports 42. As long as fuel is being drawn into the pumping chamber this difference in pressures will be at least equivalent to a liquid head represented by the difference between the liquid levels in the pumping chamber and in the storage tank 25. Therefore, the foot valve 44 cannot rise from its seat as long as fuel is being drawn into the pumping chamber.

As before noted, when the ball valve is lifted from its seat the pressure inside the pumping chamber becomes substantially atmospheric, leaving the Weightof the foot valve a l as the only force tending to keep the foot valve closed when the storage tank is empty. Against this is the opposed head of fuel in the pumping chamber which lifts the flapper from its seat and permits fuel to flow 1:1

into the storage tank until the levels inside and outside the pumping chamber are equalized. Theoretically it might be supposed that the liquid level inside the pumping chamber would remain at all times higher than that outside the chamber by a liquid head equivalent to the weight of the foot valve. In practice, however, this does not hold, due to the fact that the flapper is raised an appreciable. distance above its seat by the flow of fuel against its lower surface and at the theoretical time when the valve should reseat itself, it is still in the processv of settling down against the liquid flow. Therefore the two liquid levels of the fuel in the storage tank if and the pumping chamber become very nearly equalized before the foot valve is finally closed.

When the liquid level in the pumping chamber begins to fall, fuel will begin to drain from the float container through the ports 59. As the liquid level in the float container falls, the effective buoyancy of the float will gradually decrease until equalled by the weight of the ball valve. The float and ball valve wil then descend as a unit at the same rate as the lowering liquid level until the ball is seated, thereby completing the cycle of operations.

As the fuel rises in the storage tank, the

amount transferred from the pumping chamlfli , ing of the upper closure.

fuel in the storage tank due to the requirements of the motor is automatically compensated for until the liquid flow is in equilibrium.

It should be noted that there are only three moving parts which at no time during the operation of the device rest on other parts in relation to which they are moving.

What is claimed is:

l. A liquid fuel feeding device comprising a vacuum actuated fuel pumping means, a fuel storage tank in communication therewith, and a lower and'an upper closure for the tank, said lower closure formed with a depressed portion which rigidly receives the pumping means and provides a sediment sump, said upper closure formed with a depressed portion having an opening through which the pumping means freely extends whereby air is admitted to the storage tank and any fuel passing from the tank to the depressed portion is containedtherein until it drains back into the tank.

2. A fuel feeding device comprising a storage tank having a lower and an upper closure,

a suction actuated pumping means rigidly mounted in said lower closure and extending through an opening in said upper closure with an air-leak fit for the admission of air to the tank, and a detachable cap secured with the pumping means and acting to hold the upper closure operative, said cap having an opening for the admission of air to the open- 3. A fuel feed comprising a pumping chamber having a. fuel inlet and a valve controlled fuel outlet, a float compartment'having an unvalved primary fuel inlet at the 1,, bottom thereof and a secondary inlet port at an upper portion thereof, an atmospheric vent for the compartment, a valve for the vent, a float arranged in the compartment to rise with the fuel level therein to unseat the valve, and a suction port for the compartment, said primary inlet being of less area than the fuel inlet whereby the fuel outside the compartment will rise more quickly than that inside the compartment, said secondary port being of relatively large area to permit unrestricted inflow of fuel into the com- Gil partment when the outside fuel level reaches said secondary ports whereby the float will quickly respond and unseat the valve.

l. In a fuel feed apparatus, a storage tank having a removable closure, an inlet compartment arranged within the tank and projecting through'the removable closure, a suction pipe connected to the projecting portion of the compartment, means within the compartment for controlling the admission of liquid fuel thereinto, said compartment having valved communication with the tank, and a cap receiving the projected, portion of the compartment and seating on the closure to secure the latter against unauthorized displacement, said cap having a slot receiving the suction pipe and interlocking therewith to secure the cap thereto against accidental displacement, f .7 v .-.1 T .i

' 5. In a liquid fuel feeding device, a storage tank open at its top, an inlet compartment secured tothe base of the tank arranged thereimsaid compartment extending through the open top of the tank, a removable closure forthe tank throughwhich the compartment projects," said compartment having valved communication with the tank adjacent its lower portion, said tank having an outlet, an li'llGi) for the compartment, means within the compartment for lifting fuel thereinto, and a cap enclosing the upper end of the compartment and removably interlocking therewith,

said cap engaged with the closure for securing the same in position.

6. In a liquid supply device, suction actu- 'ated pumpingmeans including a tubular a storage tank communicating with casing, the pumping means through a liquid outlet portin the latter, said tank having a closure portion with an opening receiving said tubular casing with an airdeak fit, said closure portion having a depending flange defining said opening and constituting bafiie means to direct any splashed liquid in the storage tank downwardly and away from the air-leak fitted portions. V 7. In a liquid supply device, suction actuated pumping means including a substantially closed tubular-casing having a valved air inlet port and having a fuel outlet port adjacent the bottom thereof, a storage tank disposed about said casing and communicating with said outlet port, a detachable closure for said tank having an opening receiving the casing with an air-leak fit, and a cap having an air vent secured over said detachable closure and tubular casing.

8. In a liquid supply device, pumping means including a tubular casing having a peripheral enlargement at its lower end, a storage tank disposed about said casing and enlargement and having a fluid discharge opening above the level of said enlargement,

said enlargement having a fluid port therein, and an annular valve extending about the tubular casing and guided thereby, said valve being in the storage tank and normally closing said fluid port.

9. In a. liquid supply device, pumping means including a pumping chamber, a storage chamber,said pumping chamber having a tubular part provided with a port discharging upwardly into said storage chamber, and a valve in said storage chamber normally seating over said port, said valve engaging said tubular part for being guided thereby between seated and unseated positions.

10. In a liquidsupply device, a float con- ,tainer, a closure therefor having an inclined depressed central portion providedwith a central air inlet opening,'a ball valve seated in'said opening, said valve being guided to its-seat by the inclined depressed portion, a float in said container having undulations thereon for engagement with the ball valve when the fioatis raised, the space between I said undulations providing air passages between said inlet opening and the container interior.

RICHARD W. DAVY.

Images