US1803687A - Vacuum tank - Google Patents

Description

May 5, 1931.` J. L. ANDREWS VACUUM TANK Filed Jan. 18. 1929 Patented May 5, 1931 UNITED vsT.ar-eis,

`v1,803,6fri

PATENT oFFlCE WARNER CORPORTON, GF GEIICiG-O, ILLINOIS, A. CCIRVPR-ATION OF VIRGINIA ,i

VACUUM TANK Application filed January 18, 1929. ySerial No. 333,322.

, 'Ihe purpose of this invention is to provide an improved construction of a vacuum tank so-called, for lifting fuel by suction from a low level fuel source to a receptacle from'` ated connections for controlling the atmosphere valve comprising a novel snap action suited to an inwardly opening atmosphere valve, which, by reasonof being thus inwardly opening, tends to be opened by the suction. It consists in the elements and features of construction shownl and described as indicated in the claims. A

In the drawings Figure 1 is a vertical section of a vacuum tank embodying this invention.

'Figure 2 is a view similar to Figure l showing the atmosphere valve and float and connections at the closed position of the atmosphere valve. Y y

Referring to the drawings, theouter tank member comprising the fuel reserve chamber,

is indicated at A, and the inner member'constituting the vacuum chamber is indicated at B. The vacuum chamber has suction' connections shown at v2O adapted forv connection, as'bya pipe, 21,-'with a-source of'suction, which may be ther intake manifoldV of the engine.. This suction connection is formed with a very narrowly restricted suction port, seen at' 22, without valve control,V and consequently continuously open for access of suction from the suction source. Fuel supply connection is seen at'30 with the pipe, 3 1,

which maybe understood as leading to a main fuel supply tank at a lowerV level. `The vacuum chamber discharges into thefuel reserve chamber at the bottonn-sald discharge l 4;5 being controlled by an outwardly opening flapper valve, 40, arranged to open by gravity and fuel'fiow, and to be seated by suction due to partial vacuum in the vacuum' chamber; At the top,.the vacuum chamber has an atmosphere inlet port,50",controlled by an upwardly seating, downwardly. and inwardly opening valve, 50, having its stem, 52, eX- tending out upwardly through the atmosphere port and provided with a light coil spring, 53, for yieldingly holdingthe ,valve normally seated, said spring reacting between an adjusting nut, 54, on the valve stem and the top wall of the vacuum chamber where the sprinfr seats on the margin of the atmosphere port 55, is a dust screen over the atmosphere port and enclosing .the protruding stem and spring mentioned.

` `Within the vacuumchamber, B, a float, 60,

JOHN LEWS ANDREWS, OF ELMWOOD PARK, ILLINOIS, ASSIG-NOR T STEWART- has a downwardlyextending guide stem, 61, Y

which obtains guidance in av spider, 62, mounted at the fuel discharge port.l .Said guide stein is provided with astop shoulder at 64 for limiting the descending movement of the ioat by encounter of said stop shoulder with the spider. The'atmosphere valve, 50, is provided with an inwardly extending stem, l, which is connected slidinglyf with the valve, the latter-being bored ,from the lower end as seen at'50, to accommodatethe sliding movement. of the stem with respect to the valve, said stem having a head, 51a', at its upper end, which is .stopped on a bushing, 51", screwedinto-the lower-end of theaxial bore, a, in whichin the sliding` ofthe stein lrelatively tothe valve saidhead of the stem hasplay between the upper end ofthe bore and the lupper end of the bushing by which the movement of the stem relatively to the valve is limited. The stem, f5l, at its lower end is connected by two equal similar links, 56, 56, with the upper` ends of resilient laterally separated arms,.57, 57, which are secured v at their lower ends to the iioat at `opposite sides thereof, and extend upwardlypast the upper end of the floatfor connection at their upper ends with said links,`56, 56, respectively. Said links land arms are 1formedand dimensioned so that the upper ends ofthe arms at which they are connected respectively to the opposite free ends ofthe links, 56,

56, are normally spaced apart-aless distance than the sum ofthelengthlofthetwo 4links or so that whensaid links are extended horizontally inA opposite directions from their pivotal connectionvto the lower end of the stem, 51, the armS,.57, 57, are spread apart atV their upper ends, tending to react resiliently toward each other. The purpose and result of this construction is to produce a snap action for effecting the opening or closing movement of the atmosphere valve in the descending and rising movements, respectively, of the float, as may be understood by com parison of Figures l and 2.

Starting with the apparatus empty and connected with a source of suction and with a source of liquid, the atmosphere valve is held closed by the upward thrust of the stem, 52, which is caused by the reaction of the spring arm, 57, 57, transmitted by the links,

56, 56, supplemented by the reaction of the spring, 53, the float, 60, at this positio-n being stopped by the encounter of the shoulder, 64, of its .guide stem, 6l, on the spider` 62, so that the reaction of the spring arms, 57, operates ,against the positive stop afforded by the spider, 62, and produces an upward thrust on the stem, 5l, causing its head to traverse the lost motion space, in the valve, 50, and stop at the upper end of said space with a certain amount of pressure for holding the valve seated.

As the chamber fills with liquid drawn in by the'su'otion, the liquid rising and submerging the float causes the lat-ter to rise and spread the links, 56, against the reaction of the spring arms, 57 lifting the links into horizontal alignment, as seen in dotted line in Figure 2 when the liquid has risen to the level indicated bythe dotted line, 8l. On passing this level the lsnap action of the con nect'ions lifts fthe float to fa position shown in full li-ne in Figure ll, the links, 56, at their outer ends encountering the top of the chamber and causing the further reaction to retract the stem, 5l, into contact of its head with the bushing, 5l", which forms the lower limit of the lost motion space, the reaction of the spring arms, 57, being suilicient-supplemented by the suction action on the valve VO--to overcome the resistance of the spring, 53, and retract the valve to open position as seen in Figure 1.

The free admission of the atmosphere defeating the vacuum in the chamber, permits the liquid content to be discharged past the valve, 40, and when the liquid is lowered to `Athe level indicated by dotted line, 82, on Figure 1, the weight of the {ioat brings the links,

I56, 56` into horizontal alignment at the posi- 'tion shown in ldotted line in Figure l; and upon slight further lowering of the level the snap acti-on occurs, depressing the float the short distance necessary to bring the shoulder, 64, of the float stem into stopped position against theV spider, 62, whereupon the further reaction of the spring arms, 57, causes the links, 56, to thrust the stem, 5l, upward, causing its head to traverse the lost motion space and 'encounter the valve at the upper end thereof and thrust it to seated po sition as seen in Figure 2. lt will be noted that in the action described when the atmosphere valve is closed, the partial vacuum in the chamber operates for suction upon the valve, 50, tending to open it against the reaction of the spring, 53, so that the force required to be exerted by the spring arms, 57, for opening the valve, may be relatively small. And it will be further noted that in the snap action for closing the valve the reaction of the spring arm, 5T, is supplemented by the reaction of the spring, 53, so that on both accounts and for both actions a limited elastic 'eaction is required of the spring arms, 57.

But it should be understood upon considering this construction that the spring, 53, which reacts for seating the valve against the suction will necessarily be conditioned for such reaction to supplement the spring arms, 57, for overcoming the suction pull on the valve in opening direction under conditions of maximum suction in the operation of the structure on an automobile, under which circumstances the degree of vacuum and suction in the vacuum chamber, disregarding friction and inertia of the fuel in the supply line, is measured by the lift of the fuel from the low level fuel source to its discharge in the vacuum chamber; and that this lift varies from minimum, when the vehicle is on descending grade, to maximum when it is on ascending grade. And for fully seating the valve, therefore, such spring, 53, will in practice be conditioned to supplement the spring, 57, for holding the atmosphere valve seated against the suction resulting (disregarding friction and inertia) from the position of a car on a maximum ascending grade. For practical service, therefore, the spring, 53, will be conditioned so than-taking into consideration the assistance which will be afforded by the reaction of the spring arms, 57, 57, for resisting the suction pull in the snap action which occurs upon the rise of the iioat for opening the valve,-it will hold the valve seated against suction,-disregard ing friction and inertia,-to effect a 40 inch lift of the fuel.

And the float will have to be dimensioned so that its buoyant Value at maximum submergence will be sufficient to overcome the resilient reaction of the springs, 57 which in turn must be sullicient to overcome the excess of the resilient reaction of the spring, 53, over the suction due to the vacuum which will exist in the vacuum chamber when the fuel lift is less than the maximum, even to the minimum, as when the vehicle is on a maximum descending grade rendering the vacuum minimum. And it will be understood that the spring arms, 57, 57 will be conditioned for their resilient reaction correspondingly to the required buoyant value of the float. In practice the stiffness of the spring arm, 57, and the dimension'of'theV disregardiiig friction and inertia of the fuel in the supply line. And if by reason of such friction, inertia and other obstruction impeding the flow from the main supply tank, the vacuum` developed in thejvacuuin chamber reaches a higher degree than that measured by the maximum fuel lift alone, i. e., disregarding friction and inertia, the valve will not be fully seated ;V and by this means the flooding of the apparatus a-nd V foaming and carrying over ofthe liquid fuel into the engine intake manifold, which would otherwise happen under such circumstances, is prevented.y

It is preferred to have the spring arms, 57, 57 of such stiffness that their reaction shall constitute the necessary force for seating` the valve in conjunction with the reaction of the spring, 53, and the necessary force for opening the valve in conjunction with the suction. And in practice the spring, 53, is made only stiff enough to offset the suction on the valve at the degree of vacuum resulting in the vacuum chamber from manifold vacuum not exceeding 2 Hg. which is not more than one-fourth the vacuum which will be experienced in the vacuum chamber under running conditions and with Vfuel lift tending to produce the maximum vacuum. The reaction of the spring arms, 57, for offsetting and overcoming the suction pull on the valve in opening direction is therefore about four times that of the spring, 53, for. the same result.

Upon considering the construction it will be seen that the spring, 53, may be dispensed with by making the spring arms, 57, of such material and dimensions and so conditioned for their reaction, that thatreaction alone shall be sufficient to overcome the suctionV pull on the valve for opening under the conditions of maximum suction as' above indicated.

I claim l. In an apparatus for lifting fuel by suci' tion, in combination with a receptacle to which the liquid is to be lifted, having conatthe lower part with an outlet controlling valve; a continuously open suction port and an atmosphere inlet port; an inwardly opening valve controlling the atmosphere inlet port; spring means reacting against a part fixed with respect to the valve seat for holding said valve normally seated againstthe suc tion; a fioat in the chamber and operating connections from the float for moving the atmosphere valve inwardly by the buoyant effort of the oat against the resilient reaction fof thespring-valve-seating means upon predetermined rise of level of the liquid in the chamber.

2. In combination with a receptacle to which liquid is vto be lifted, having a liquid supply connection leading from a low level source of liquid, said chamber having a valve-- controlled atmospheric inlet and a valve-con- -trolled liquid outlet; an inwardly opening valve controllingthe atmosphere inlet port, whereby the suction due to partial vacuum in the chamber tends to open said valve; a spring reacting lon said valve and against a part fixed with respect tothe valve seat for holding it in opposition to suction tending to open it; a iioat in the chamber and operating connections from the float for moving the atmosphere valve in opposition to the suction upon the rise ofthe. liquid in the chamber to predetermined level.

3. In the construction defined in claim2, the atmosphere valve having its stem protruding out throughthe atmosphere inlet port,I and a spring at the outer side of the port reacting between the chamberwall adjacent the port and the protruded valve stem, and an adjustable stop on the valve stem by whose adjustment .the spring may be adjustably conditioned for its reaction for holding the valve seated.

4. In the construction dened in claim 2, the atmosphere inlet valve having a stem extending within the chamber, said stem being mounted ,for lost motion relatively to the Valve in the direction for seating and unseating the valve; connections from the float to said interiorly extending stem arranged for .stressing the valvel inwardly away from its seat upon the iioat being lifted by the rise of .theliquid level past a predetermined liquid nadapted to operate for pulling the stem in the direction for opening the valve by the snap movement, the range of lostmotionofthe stem f with respect to the valve corresponding to the rising movementof the vfloat from the encounter with the snap action connections to the critical point of the snap action.'

. ,5. In a construction defined in claim 2, a snap action consisting of a pair of links pivotally connected to the valve stein and exnection for liquid inflow and a liquid outlet .tendmg m the Opposlte dlrectlons from t elf the operating connections from the float consisting of a lever` snap action comprising spring means for causing the snap action conditioned for their springreaction to. exceed ltr() that of the spring which hold the valve normally seater.

7. In the construction delined in claim l, the operating connections from the lioat consisting of a lever and snap action comprising a pair of levers pivoted together and a stem connecting their pivot with the valve, and spring arms rigidly attached to the float and extending upwardly from their said attachment for engagement with the levers respectively, whereby said spring arms are spread apart and react resiliently toward each other when the levers are brought into alignment with their pivot.

8. In a construction for the purpose indicated comprising a chamber for liquid and a valve at the top of the chamber controlling atmosphere access to the chamber; a iioat in the chamber; a pair oi levers pivoted together and connected from their pivot with the valve; spring arms symmetrically positioned on the float and secured thereto at one end, and having their other ends pivotally connected with the levers respectively, said spring arms being resiliently adapted to be spread apart at their lever-connected ends a distance for aligning the pivots of the spring arms to the levers with the pivot of the levers to each other and to react for folding the levers at an angle to each other upon the spring arm pivots passing the position of such alignment; whereby there is provided a snap action for thrusting the valve toward and from its seat by the rising and falling of the float, lifting and lowering the spring arms past such aligned position.

9. In the construction defined in claim 8, means in the chamber for arresting the up- ,ward movement of the free ends of the levers at a position short of that at which the resilient reaction of the spring arms for folding the levers upward is exhausted; whereby the further reaction in the direction corresponding to the upward movement of the float operates for thrusting downwardly the pivot of the levers to each other for actuating the valve in unseating direction.

10. In the construction defined in claim 8, means in the chamber for stopping the downward movement of the float at a position short of that at which the resilient reaction of the spring arms for folding the levers downward is exhausted; whereby the further reaction in the direction corresponding to the downward float movement operates for thrusting upwardly the pivot of the levers to each other for actuating the valve in seating direction, the connection of the lever pivot with the valve being by a stem pivotally connected with the lever and having lost motion connection with the valve permitting relative movement between the valve and the stem less than the up and down movement of the lever pivot from the position of alignment of the levers.

l1. In the construction defined in claim 8, means in the chamber for arresting the upward movement of the free ends of the levers at a position short of that at which the resilient reaction of the spring arms for folding the levers upward is exhausted; whereby the further reaction in the direction corresponding to the upward movement of the ioat operates for thrusting downwardly the pivot of the levers to each other for actuating the valve in unseating direction, the connection of the lever pivot with the valve being by a stem pivotally connected with the lever and having lost motion connection with the valve permitting relative movement between the valve and the stem less than the up and down movement of the lever pivot from the position of alignment of the levers.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 27th day of December, 1928.

J. LEWIS ANDREWS.

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