US1812014A - Limited suction feed device - Google Patents

Description

.lune 30, 1931. w. H. MUzzY v 1,812,014

LIMITED sUcTIoN FEED CDEVICE Filed sep. 21, 1929 zsneets-sheet 1 i A azazvaqye.,

June 30, 1931. w. H. Muzzv 1,812,014

LIMITED SUCTIQN FEED DEVICE Filed sept. 21. 1929 2 sheets-sheet `2 4 a 4/ 66 40 4 56 2f s 7 5 @AA/mm Cit Patented June 30, 193

i UNITED srarzes PA'iNT FFM@ -WILLIAI'I H. MUZZY, OF EVANSTON, ILLINOIS, ASSIGNOR 'IO PORTION, OF CHICAGO, ILLINOIS,

STEWART-WARNER Cone conronn'rion or VIRGINIA LIMITED SUCTION FEED DEVICE Application filed September 21, 1929. Serial No. 394,152.

The purpose of this invention is to provide a construction for limiting to a predetermined degree the vacuum which Will be develcped in the vacuum chamber of a vacuum tan-k connected With a source of vacuum such as the intake manifold of the engine served, in which the vacuum is liable lto be much greater than it is desirable to have developed in the vacuum tank. It consists in the elements and features of construction shown and described'as indicated in the claims.

In the` drawings:

igure l is a vertical axial section of a vacuum tank constructed according to one form of this invention.

Figure 2 is a similar vievv of the second form of the invention.

Figure 3 isa similar view showing athirdV embodiment of the invention.

Figure 4 is a similar view showing a fourth form of the same generic invention.

Tligure 5 is a diagrammatic view showing in elevation the vacuum tank'and ,the main fuel supply tank, the latter being broken anayfor showing Within the tank an arrangement of air and fuel floiv adapted to allow the vacuum tank to operate according to the principle of this invention and therefore' to embody said invention in a fifth form.

Referring in general to .all the forms of the invention shoe-,vn in the several figurest vri-l be understood that the vacuum tank is arranged te supply fuel to the engine carbuaeter by gravity, the vacuum tank being posit'ieneu at a suitable height abcve the level of the carhureter for that purpose; thatthe vacuum tank is of the tivo-chamber type comprising an upper chamber in which the vacuum is developed by` pipe connection thereto from the intake manifold of the engine., and a reserve supply chamberlinto which the fuel is delivered by gravity from the vacuum chamber; that the vacuum chamber has pipe cennection by which it derives supply of fuel from a main tank situated at the lower level, and from Which the fuel is lifted to the vacuum chamber by suction duek to the rdegree of vacuum which is developed in the vacuum chamber., by itsV connection with the engine intake manifold when an atmosphere inlet port, with which the vacuum chamber is furnished at the top, is closed by the valve provided for that purpose, While the .communication .vith the intake mani-y fold is open; that the atmosphere inlet valve is operated for opening by a float inthe vacuum chamber when the latter becomes filled to a certain depth with fuel sucked up from tl e main tank; that the fuel is discharged into the lower chamber past a valve which is held closed by the suction While the vacuum chamber is being filled to a depth at whichV the float lifted by the risingk liquid opens the atmosphere valve; vand when the atmospheric pressure thus admitted offsets the vacuum due to the connection With the vengine intake manifold, the liquid is discharged by gravity opening the outlet valve at the bottom of the vacuum chamber;

lt Will be understood further that in the l most common' form of vacuum tanks the opveration in this mannen-that is by the opening of an atmosahere Ivalve admitting air toy relieve the vacuum, is ensured by providing a valve vvhich cuts off the suction at the same instant that the atmosphere valve is opened, so that the vacuum existing in the tank, and

by Which thefuel has been lifted to lill the i vacuum chamber to apredetermined depth, is prcmptly'neutralized by the inrush of air when the atmosphere valve opens. But if no valve is present to cut off the suction, or if the valve provided for that purpose is poorly tted or Worn, or is kept from seating properlyv by dus-t particles, it Will be lunderstood that-indien the engine vacuum is high the air may not'flovv in through the atmosphere valve rapidly enough to overcome the vacuum, because the air thus flowing in may be sucked out to the engine'intake manifoldas fast as it can come in through an atmosphere inlet. rindif this dii'licu'lty or defect is attempted to be metby making the atmosphere portso large that the-air inflow will offset eventhe maximum suction due to intake manifold vacuum operating through the suction po-rt Without valvel orl unseated valve, -it may be seen that the force ncessaryto openv the atmosphere valvegagainst the suction When the engine intake vacuum is high Will require very large float, or, on the other hand, will necessitate making the suction port very small, resulting, in the first case, in requiringl the vacuum tank to be much larger than otherwise necessary and larger than desirable, and in the second case, in making the filling operation very slow, reducing the fuel supplying capacity of the tank of a given size.

rlf'he present invention in each of the forms illustrated obviates these defects of vacuum tanks of present common construction, by providing means preventing the vacuum developed in the vacuum chamber exceeding a predetermined degree, regardless of the high degree of vacuum derivable from the intake manifold.

Referring to the construction shown in Figure 3 which shows the simplest form of the invention z-The vacuum tank comprises a vacuum chamber, A, and a reserve supply chamber, B. A vertical tube, 20, of small diameter is provided extending up int-o the vacuum chamber, A, and down into the reserve supply chamber, B. rlhis pipeat its top in the vacuum chamber, A, is provided with a weighted valve, 2l, having a guiding stem, 22, and arranged tonormally close the upper end of the tube, 20, the lowei` end of which is open in the fuel reserve chamber as mentioned and as seen at 23.

A cork fioat, 25, is mounted on a stem, 26, which carries at its upper end an atmosphere inlet controlling valve, 27, seated on a valve :i seat, 28, formed inthe top, 29, of the vacuum tank. The lower end of the stem, 26, is guided in a pipe, 30, which constitutes the dr in outlet of the vacuum chamber by which the fuel is discharged into the reserve supply chamber, B, past the customary flapper valve, 3l.

rlhe reserve supply chamber, B, is provided with a stand pipe, 82, which communicates with the outlet, 33, fro-m which pipe connect-ion indicated at 33 leads to the carbureter.

A fitting, 34, connected at the top of the vacuum tank affords connection for the suction pipe indicated at 35 arranged to lead to the engine intake manifold. rlhe suction port at which the fitting, 35, is connected is very small as seen at 36 being preferably of about the size of a #72 drill. A fitting, 37, affords connection with the top of the vacuum tank for the fuel supply pipe indicate-d at 37a and which may be understood as leading from the main supply tank at the rear of the vehicle.

The atmosphere inlet port, 28, furnished with the atmosphere valve, 27, is guarded by a casing, 40, having a goose-neck breather pipe, Lil, of usual construction.

The purpose of the stand pipe, 32, is to ensure that a certain amount of fuel will always be trapped in the lower part of the reserve supply chamber, B, thus guarding against any liability of this amount of gasoline being drained off even though the tank is otherwise completely drained and exhausted of supply available for the carbureter.

'The operation of the structure will be understood from the foregoing description, but may be further indicated. Assuming the vacuum tank to be primed,-that is initially supplied with fuel occupying the lower reserve supply chamber, B, and standing in the vacuum chamber at the low level .at which the atmosphere inlet valve is held closed by' the weight of the ioat,-When the vacuum developed in the vacuum chamber by connection with the intake manifold reaches a suliicient degree, gasoline is drawn from the main tank .at the rear of the machine through the pipe connection, 37.

And when the vacuum is sufficient to lift the weighted valve, 2l, gasoline also passes up in the pipe, 20. As the inflow to the vacuum tank due to the engine suction and resulting vacuum in the vacuum chamber raises the level in the vacuum chamber, when the liquid reaches a predetermined height in the vacuum chamber, `the float will open the atmosphere valve, which, however, is dimensioned for being thus opened only against a predetermined vacuum, desirably not exceeding five inches Hg. 1n the ordinary operation the valve, 2l, remains closed up to a vacuum of about three or four inches Hg.

. and the full force up to this degree is utilized for lifting the fuel from the rear tank. But when the vacuum in the chamber, A, exceeds three or four inches, Hg. the valve, 21, opens and is carried up on a column of gasoline which is sucked up in the pipe, 20. The gasoline thus enters the chamber, A, with sufficient rapidity to prevent the vacuum in that chamber exceeding five inches Hg. and to cause only a limited amount of air to pass the small suction aperture, 36. The relation between the weight of the valve, 21, and the size of the aperture, 36, determines the degree of vacuum which will be developed and maintained in the vacuum chamber, A.

Upon relief of the vacuum of this limited degree which is effected by the opening of the .atmosphere valve, by the rising of the float, the fuel is discharged by gravity to the reserve supply chamber, B, passing the lapper valve, 3l, according to the usual operation of vacuum tanks of this type.

Referring to the form shown in Figure 2 z-In this embodiment of the invention, the vacuum relief is aorded by admitting air directly from the atmosphere, instead of admitting the liquid from the lower chamber under atmospheric pressure. For this purpose there is provided at the top of the vacuum chamber a vacuum relief or atmosphere vent port, in addition to the atmosphere inlet reiger-i which is controlled bythe float-operated valve. This relief port is provided in a fitting, 50, inserted in the cap, 29, of the vacuum chamber, .an-d having for controlling it a valve, 51, having a long tapering shank, as

seen at 52, and terminating in a threaded stem, 53, for receiving an adjustable stop nut, 54, a spring, 55, being coiled about the stem and reacting between the stop nut and shoulder, 56, formed in the fitting, 50, by

the description of the operation of the first described form withou scription.

Referring to the embodiment of the invention shown in Figure 4 y In this embodiment the vacuum is relieved by the admission of both atmospheric air and liquid drawn from the reserve supply chamber. In this form the operation of the float and other parts is the same as above describec further specific de- `'in respect to the form iirst above described.

In this form there is provided a. loop pipe, 60, having its bend at the lower part of the reserve supply chamber and having one limb, 61, extending (liquid iight) through the bottom of the vacuum chamber, A, and the other limb, .62, extending outside the vacuum chamber in the annular space, B1, around the same within the reserve supply chamber, B, both limbs of the U-pipe are open at the upper end, the first mentioned limb thus being open to the pressure existing in the vacuum cham.-

ber and the other limb being open to an ati-- mospheric pressure which is always operative a in the reserve supply chamber which it will be understood has the yatmosphere inlet at the upper end as soon at 19.

VThe loop pipe, .60, has at its lower end an aperture, 63, by which liquid is admitted from the reserve supply chamber, B, and drawn upward in the limb, 61, mixed with air which is at the saine time drawn -down from'the limb, A62, and passing around the bend men-` tioned with the liquid moving upward in the limb, 61'.

ing the trapping of liquid inthe lower part of the. reserve supply chamber, B, and thus ensures that the liquid will 'oe always drawn in through the port, 63, the friction of which in the pipe will operate with the effect for restricting entrance of liquid and air, which is the function of the. weighted valve in the form shown in Figure 3, and of the-spring, 55, in the form shown in Figure 2. And it may be understood that the form and dimensions The stand pipe., 32, operates 'as inthe previously described form, for ensurof this loop pipe, particularly as to diameter, will be determinedexperimentally for limiting the vacuum in the vacuum chamber to the predetermined degree. And it will be understood that the weighted valve may be applied at the discharge of the limb, 61, as in the form of Figure. 3, to supplement the restraint of flow obtained from friction in the pipe.

The operation of 'this form may be readily understood from the foregoing description thereof and of the description of the operation of the previously described form.

Referring to the form shown in Figure 1 In this embodiment of the invention the operf ation is identical in principle and very similar in detail to that shown in Figures 2, 3 and 4 above described, the difference consisting in that auxiliary structure for controlling the vacuum is located Within the vacuum chamber. Y

Said auxiliary structure comprises what might be regarded as a miniature vacuum tank, having a chamber which is in communication with the vacuum chamber, and experiences the same degree of vacuum, and a lower chamber which is at all times under atmospheric pressure, 'and into which the liquid content of the first mentioned upper chamber is delivered by gravity when the atmosphere inlet is opened by the float, said float being located in the upper chamber of the auxiliary device and the valve which it controls being a "ranged to admit atmosphere not only to said auxiliary device but also to the main vacuum chamber of the vacuum tank.' 1^

Referring to the structure in detail :HThe auxiliary structure c-omprisesa. Vcup-shaped sheet metal stamping, 80, open at its upper end and flanged for securing itat that end to the under side of the cap, 29, of the vacuum tank, the cavity of said cup memberA being partitioned as'seen at 81 fo 1ming an upper vacuum chamber, 82, and a lower chamber, 83. The member, 80, has at its upper part a plurality of apertures, 84, aifording free communication between the upper chamber,

.82, and the vacuum chamber, A, of the vacuum tank. A pipe, 85, open from end to end, eX- tends from the partition, 81, up through the chamber, 82, and through the cap, 29, into the chamber, 40, with which the goose-neck breather pipe, 41, is connected for admitting atmosphere to the atmosphere inlet port, 38, and the atmosphere controlling valve, 39, has

its stem, 26X, extending down in the chamy iii-i in the lower chamber, 83, to nearly the bottom thereof, is open at both ends, thereby affording free flow communication between the two chambers, 81 and 82. A pipe, 88, mounted in the partition, 81, extends up in the chamber, 82, to about the level of the apertures, 84, and extends down in the chamber, 8l, to the saine level as the pipe, 87, said pipe, 88, being` open at both ends thereby affording comn'iunicati-on to the lower part of the lower chamber and to the upper part of the upper chamber, 82.

The operation of this construct-ion may be understood from the fore-goin@ description but may be further descril ed The apparatus being primed, that is, having the lower chamber occupied with liquid extending up in the annular space, B1, between the two chambers, A and B, to the low level, that is the level to which the liquid falls when discharging into the lower chamber when the atmosphere inlet is open ,-engine suction operating for developing vacuum produces vacuumy in the vacuum chamber, A, and in and to the same degree the chamber, 82, of the auxiliary structure causing the inflow ofr liquid entering the vacuum chamber rising therein to the level of the port, 89, enters the chamber, 82, of the auxiliary structure and flows therefrom by way of the pipe, 87, into the lower chamber, 8l, of the auxiliary structure causing that chamber to be filled sealing the lower end entrance to the pipe, 88, through which the liquid is sucked up by reason of the vacuum in the. chamber, 82, and discharged from the upper end of pipe, 88, accumulating in the chamber, 82, to the level to which at the saine time it accumulates in the main vacuum chamber, A.

The liquid thus acciunulating in the chamber, 89 causes the float be lifted and to open the atmosphere valve, which the discharge of the liquid contents of the vacuum cl into the reserve suppl v same time the ,d

charge her, 82, chamber,

will be une l which wil: bdc in the main vacuiu itcd l y the i c c in vacuum cl amber, A. wil lle understood that the pi s mentioned wi" be dimensioned bv e.A lnent for rende i nce te the L flew such te, overcome by vacuum of tlic predeterm degree de feioped in the vacuum chambers, and A. lt wil be understood also that the return iow of the liquid from the chamber, 82, to the chamber, 81, when the 'atmosphere valve is open, ensures the presence at all times in the chamber, 8l, of the necessary quantity of liquid to operate for sealing the lower end of the pipe, 88, and 'supplying that pipe completely with liquid in the upward flow for discharge in the chamber, 82, for relieving the vacuum. l

Referring to the construction indicated in Figure liz-lt may be understood that the construction of vacuum tank, V, is substantially the same as that shown in thc previously described figures in respect to the vacuum chamber, reserve supply chamber, fuel supply connection (by the pipe, 90), valveless suction connection, atmosphere inlet with valve control by float in the vacuum chamber, and bottom outlet from the vacuum chamber to the reserve supply chamber with valve seated by the suction and opened by gravity discharge of the liquid when the vacuum is relieved by the opening of the atmosphere valve by the float.

in this form the relief of vacuum is afforded by ineansof pipe, 91, in the main fuel supply tank open for free access of atmosphere at its upper end, and connected at the lower end into the fuel intake pipe, Q3, near the lower end intake thereof as indicated at 94.

lt will be recognized upon careful consideration 'that whatever the degree of vacuum derivable in the vacuum chamber of the vacuum tank from the engine intake manifold,`

the vacuum actually resulting in the chamber will be measured by-or be the measure cf the resistance of the liquid column eX- tending from the liquid level of the main supply tanl: to the level of fuel discharge in the vacuum tank; and that this resistance consists of the hycirostatic value of the liquid column per se plus the resistance to movement of the liquid in the conduit due to friction and viscosity of the liquid and restriction of access of liquid to the pipe.

It will be recognized that with the pipe large'enough to render the frictional resistance negligible, the vacuum in the vacuum chamber would be at all times measured by the hydrostatic value of the liquid column in the supply pipe. With the intake to the fuel supply pipe in the main supply tank sealed by the liquid therein, an excess of vacuum in the vacuum chamber to over predetermined degree less than the vacuum theoretically derivable from the intake manifold, will be due to restriction of access of liquid to the supply line, or to other resistance to flow therein. Upon consideration it may be recognized that the provision afforded by the air inlet pipe, 91, for access of air to the liquid column in the pipe line 93, 90, will cause said liquid column to be aerated and thereby reduced in density and weight, and correspondingly reduced in hydrostatic Value; and at the same time there will be reduction in the frictional iso resistance to flow toward the vacuum tank;

'and that the delivery of the air with the liquid into the vacuum chamber will have the same effect to relieve the vacuum as the admission of air in any other manner or by any other course. Y

The dimension of the, air pipe, 91, and of its port of communication with the fuel supply pipe will be determined experimentally to limit the vacuum in the vacuum. chamber to the predetermined degree.

I claim:

l. In liquid feeding system in whichl quid is lifted from a low level supply to 'a-chamber at a higher level by the creation of a partial vacuum in said chamber and in which means is provided for periodically releasing the elevated 1liquid for discharge by gravity, said means including an atmosphere valve to vent the chamber, and a float Yconnected for opening said valve upon accumulation of liquid in the chamber; means to prevent an excessive degree of vacuum in the chamber, comprising a supplemental passage for supplying additional fluid thereto against resistance to the movement of such fluid iiow, the resistance of said passage bei-ng adapted tobe overcome by thev suction when the vacnum in the chamber exceeds a predetermined value; a supplemental chamber within the vacuum chamber having an inlet for liquid disposed below the lower limit of movement of the fioat and a transfer passage extending fiom the lower portion of said supplemental chamber to a point above the normal maximum liquid level in the vacuum chamber, said supplemental chamber being constantly open to the atmosphere, whereby excessive vacuum tends to transfer liquid from said supplemental chamber to the vacuum chamber for 'satisfying the excess of vacuum.

2. In a liquid feeding system in which liquid is lifted from a low level supply to 'a chamber at a higher level by the creation of a partial vacuum in said chamber and in which means is provided for periodically releasing the elevated liquid forV discharge by gravity, said means including an atinosphere valve to vent the ch amber, and a float connected for opening said valve upon accumulation of liquid in the chamber, means to prevent an excessive degree of vacuum in the chamber, comprising a supplemental passage for supplying additional iiuid thereto against resistance to the movement of such fluid liow, said passage adapted to be overcome by the suction when the vacuum in the chamber exceeds a predetermined value, a

supplemental chamber within the vacuum chamber having an inlet for liquid disposed below the lower limit of movement of the float and transfer passage extending from the lower portion of said supplemental chamber to a point above the normal maximum liquid level in the vacuum chamber, said sup-l plemental chamber being constantly open to the atmosphere, whereby excessive vacuum tends to transfer liquid from said supplemental chamber to the vacuum chamber for satisfying the excess lof vacuum, said float beinO' surrounded by an enclosing cup within into the vacuum chamber. 4. in the combination defined in'claim 2,

said cup being provided with an overiiow port in its upper portion to prevent floodingof the liquid through the atmosphere vent.V

5. ln a liquid feeding system in which liquid is lifted from a low level supply to a chamber at a higher level by the creation of a partial vacuum in said chamber and in which means is provided for periodi ally releasing the elevated liquid for discharge by gravity, said means including' an atmosphere valve to vent the chamber, and a float connected for opening said valve upon accumulation of liquid in the chamber, means to prevent an excessive degree of vacuum in the chamber, comprising a supplemental passage for supplying additional iiuid thereto against resistance to the movement of su-ch l fluid flow, the resistance of said passage being adapted to be overcome by the suction when the vacuum in the chamber exceeds a predetermined value; a supplementalA chamber within the vacuumr chamber having an inlet for liquid disposed below the lower limit of movement of the float, and a transfer passage extending from the lower por tionof said supplemental chamber to'a point above the" normal maximum liquid level in the vacuum chamber, said supplemental chamber having` a constantly open atmosphere vent', whereby excessive vacuum tends to transfer iquid from said supplemental chamber to the vac uum chamber for satisfying the excess of vacuum, the atmosphere vent for the supplemental Vchamber being a tube which passes through a clearance opening in the lioat and eoV the transfer passage beinga tube which exy tendssimilariy through aclearance opening in the float, whereby said Atube serves to guide the float in its movement.

6. in a liquid feeding` system in which gravity, said means including an atmosphere tion of li d in the chamber; means to prevent en .ncessive de=--ee of vacuum 1n the chamber, comprising a supplemental passage for upplying additional fluid 'thereto against resistance to the movement of such fluid flow, the resistance said passage being adapted ome by the suction when the vacuum intne chamber exceeds a predetermineir value, said loiv level` supply comprising a tank with a liquid supply tube leading upwardly from the bottom portion 'l .ereof to the vacuum chamber, the upper portion of said supply tank being subject to atmospheric pressure, and the means to prevent excessive vacuum Comprising a branch tube opening in the upper portion of the supply tank and connected into the supply tube at a point near the bottom of the tank, whereby excessive vacuum in the chamber will dranv air through the branch tube and through the supply tube to satisfy the excess of vacuum in the chamber.

Q7. in liquid reedn r in which liquid is lifted from a lov: level supply to a ciiamber at a higher level by the crea-tion of a partial vacuum in said chamber and in which means is provided for periodically rclcasing the elevated liquid for discharge by gravity, said means including an atmosphere valve to vent the chamber, and a float connected for opening said valve upon accumulation of liquid in the chamber; means to prevent an excessive degree of vacuum in the chamber, comprising a supplemental passage for su pplying addi-tional fluid thereto against resistance to the movement of such iuid flow, the resistance of said passage being` adapted to be overcome by the suction when the vacuum in the chamber exceeds a predetermined value, a reservo': communicating with the chamber to receive the liquid discharged by gravity therefrom, said reservoir being open to atmospheric pressure, and a passage connecting said reservoir with the upper portion of the chamber having outlet in the upper part of the chamber and inlet in the lower part of the reservoir, with a valve yieldingly seated with predetermined force controlling said outlet, whereby it is adapted to be opened by vacuum in the chamber exceeding said predetermined force, for admitting liquid from the reservoir to the chamber to satisfy such excess of vacuum.

Q ln a liquid feeding system in which i. liqu: l is lifted from a low level supply to a chamber at a higher level by the creation of a partial vacuum in said chamber and in which means provided for periodically releasing the elevated liquid for discharge by gravity, said means including an atmosphere valve to the chamber, and a float connected for opening said valve upon accumulation of liquid in the chamber; means to prevent an excessive degree of vacuum in the chamber, comprising a supplemental passage Vfor supplying additional fluid thereto against resistance to the movement of such fluid flow, the resistance of said passage being adapted to be overcome by the suction When the vacuum in the chamber exceeds a predetermined value, a reservoir communicating With said chamber to receive the liquid discharged by gravity therefrom, said reservoir being open to atmospheric pressure at the upper part, a passage connecting said reservoir with the chamber having outlet at the upper part of the chamber and inlet at the lower part of the reservoir, a yieldingly seated valve controlling said outlet adapted to be opened by vacnum exceeding the force by which the valve is held yieldingly seated, for admitting liquid from the reservoir to satisfy such excess vacuum in the chamber, the reservoir having its discharge outlet at a substantially higher level than the inlet to said passage, whereby liquid is trapped in the reservoir for delivery through said passage to the chamber for satis fying the excess vacuum therein.

In testimony whereof, I have hereunto setmy hand this 16th day of September, 1929.

VILLIAM H. MUZZY.

vso

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