US1868988A - Liquid-sealed pumping system - Google Patents

Description

July 26, 1932. w. H. MUZZY 1,868,988

LIQUID SEALED PUMPING SYSTEM Filed Jan. 19, 1929 2 Sheets-Sheet l July 28, 1932." H M ZZY 1,868,988

LIQUID SEALED PUMPING SYSTEM 7 Filed Jan. 19, 1929 2 Sheets-Sheet 2 f- E? 1/1 14 I ll i ill

Patented July 26, 1932 UNITED STATE'I'VS'PATEN-T OFFICE WILLIAM H. MUZZY, OI EVANSTON, ILLINOIS, ASSIGNOB TO STEWART-WARNER COB- PORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF VIRGINIA LIQUID-SEALED SYSTEM Application filed January 19, 1829. Serial No. 338,576.

' The purpose of this invention is to provide an improved construction in a pumping ap-.'

paratus for supplyin fuel to an internal combustion engine a apted to be mounted upon the engine. It consists in the elements and features ofconstruction shown and described as indicated in the claims.

In the drawin s:

Figure 1 is a iagrammatic view showing the position on a motor vehicle and its engine of the structure constituting this invention relatively to the engine carbureter and main fuel supply tank.

Figure 2 is a vertical section as at the plane indicated by the line 22 on Figure 1 of one form of pumping device embodying this invention. v

Figure 3 is a section at the line 3-3 on Fig. ure 2. a

Figure 4 is an elevation of a slightly modified form.

Figure 5 Fi ure 4.

Figure 6 is a section at the line 6--6 on Figure 5.

is a section at the line 5-5 on Figure 7 'is a section at the line 77 on Figure 6.

Figure 8 is a detail section at the line 8-8 on Figure 5.

The specific purposes kept in view in designing the construction shown include the following, viz., to provide:

First. a piston pump which shall not require lubrication, such necessity being avoided by the provision of a chamber which is kept supplied with the liquid pumped and so connected and located with respect to the piston chamber that the latter shall at all times be furnished with li uid for maintaining the piston liquid-scale dispensing with the necessity of so close a piston fit as to re uire other lubrication:

becond, to provide means preventing the liquid pumped from flowing back or being syphonedbaik to the source from which it is pumped when the engine ceases running, such back flow bein liable to occur by reason of leaky or imper ectly seating valves controlling the intake and discharge passages of the pump.

In carrying out these purposes there is kept in mind the secondary purpose of making a compact structure and one adapted to be readily applied to an engine with minimum change for adaptation of the engine details or pump details.

Describing t e invention in general terms without naming the several parts, it may be noted that the .pumping device comprises a casing adapted to be mounted on the crank case of the engine to be served, and to be connected by a fuel supply line with a main fuel supply tank carried in the customary position at-the rear of the vehicle whose engine is served and with the carbureter of the on me:

hat the casing contains a piston chamber with fuel inflow and discharge connections valve-controlled for flow from the fuel source toward the carbureter, the valves seating against reverse flow; and that the casing contains also a liguid trapping chamber arranged for deriving iquid from the pumping chamber-and flowing the same back into the pump- 7 ing chamber for maintaining the piston fliquid-sealed therein.

The construction comprises also a vacuum trap on the fuel supply line located relatively to the 'liquid trapping chamber and pumping chamber for back-flow into said vacuum trap of the liquid content of the pumping chamber and liquid trappin chamber.

It will be note further that the liquid trapping chamber is located above the pumping chamber, for facilitating maintaining t e piston liquid-sealed by gravityflow from the liquid trappin chamber to the pumping chamber, and t at the casing is formed for mounting on the. engine so as to locate the liquid trapping chamber substantially at the level of the carbureter float bowl or other governed level fuel chamber of the carbureter.

Referring to the drawings, the pumping device is indicated in its entirety at A; B indicates the carbureter float bowl; C is the main supply tank at the rear of the vehicle; D is the cam by which the pumping device is operated.

The pumping device comprises a casing consisting of a part, 30, which contains the um in mechanism roper and art 40 Erhich p ovides the medhs through vghicli thd operating connections extend into the crank case for reaching the operating cam, D. In the casin member, 30, there is located a piston cylin er orpumpin chamber, 30, havin fuel inflow connection t rough a boss, 50, an discharge connection through a boss, 60, the fuel pi e line indicated at 54 being coupled to the boss, 50, and the fuel discharge line, a leading to the carbureter being coupled to the boss, 60. 1

Furthermore, the fuel inflow passa e comprises a port, 51, in the boss, 50, whic leads to the vacuum trap hereinafter described, the

rt, 53, also in said boss leading to an enargement "which constitutes a valve chamber for valves controlling the li uid trappin chamber hereinafter describe and a fina portion, 52, which leads through thevalve seat bushing, 41, to the piston chamber, 30.

The discharge passage comprises a portion, 61, leading from the piston chamber to the port, 62, controlled by the discharge valve 63, and beyond said valve the duct, 64, leading to the coupling, 65, which connects the discharge line, a, leading to the carbureter as mentioned. The intake controlling valve, 73, seating, as mentioned at the fitting, 41, is provided with a spring, 73, interposed between it and the piston, 70, for ensuring the normal seating of said valve subject to opening upon the intake stroke of the piston, drawing in the fuel from the inflow passage. The discharge valve, 63, is similarly provided with a seating spring, 63, tending to hold it in position by the plug, 63, closing the aperture through which the valve is introduced.

The casing, 30, contains above the piston chamber, 30, the liquid trapping chamber, 31, into which the piston chamber or cylinder, 30, opens freely at its upper end. The piston, 70, is designed to be loosely fitted in the piston cylinder so that liquid may pass the piston in the forcing stroke of the latter, but this means of supplying the liquid trapping chamber with liquid for sealing the piston is not the sole reliance for keeping the trapping chamber thus supplied; and there is provided a passage, 67 leading from the discharge passage immediately beyond the discharge valve, 63 and extending up alongside the piston cylinder, 30, opening into the bottom of the 11 uid trapping chamber, 81.

pon consideration it will be seen that by this connection the feeding stroke of the iston will tend to feed liquid into the chamr, 31, while it is feeding it also through the dischar e passages and discharge line, a, to the car ureter. Only a limited portion of the liquid pumped is required for maintaining the liquid trapping chamber occupied with the liquid for liquid-sealing the piston. But the circuit through the pump and the liquid trapping chamber serves the purpose of a bypass and relief passa e for the pumpe hquid, in which an ad ustable restriction serves for regulating the pressure on the fuel line to the carburetor, said restriction being afiorded by a needle valve, 80, set through the lower end of the casing and adapted to be adjusted for choking the passage, 67, at the upwardly extending discharge portion of said passage for controlling the pressure in the fuel line to the carbureter.

The liquid trapping chamber, 31, is provided with a drain port, 55, at the bottom, said drain port leading into the enlarged vent, 52, of the inflow passage referred to as constituting the valve chamber; and it will be recognized that by this provision the pumping action of the piston, 70, will normally operate for feeding a certain amountof liquid up into the liquid trapping chamber, which would immediately flow back through the port, 55, and become part of the inflowing current to be again pumped through the pumping chamber, without efl'ecting any accumulation of liquid in the trapping chamber above the level of the drain port.-

And to insure the accumulation and retention of fuel in the trapping chamber to a level suitable for certain of the functions of the chamber as hereinafter defined, there is provided in said chamber a float, 90, having a stem, 91, extending down through the port, 55, and carrying above said port a valve, 92, which is normally seated for closing the port, being held seated by the weight of the float in the absence of liquid content in the chamber, 31; and when the pumping action of the piston has caused liquid to be accumulated in the chamber, 31, to a depth sufficient to upliftthe float, the valve, 92. will be thereby opened and permit discharge of the liquid by gravity into the inflow passage.

The vacuum trap mentioned is provided by means of a standpipe, 100, closed at its upper end and mounted on the boss, 50, encompassing the upwardly opening apertures of the ducts, 51 and 53, a standpipe member, 101, being connected at the aperture of the duct, 51, and extending upward for discharge within the standpipe, 100, at the upper end of the latter. Upon consideration it may be understood that in the operation of the pump, the intake stroke of the piston for drawing in the fuel from the main tank, 0, producing partial vacuum in the conduit leading from the pump back to the main tank, will eventually cause the fuel to be lifted to the upper end of the standpipe, 101, from which point it will fall through the standpipe, 100,

and be sucked in through the passage, 53, and 5' the remainder of the inflow passage to the pump chamber, and that in the continuing operation. of the pump, the space in the standpip'e, 100, around the standpipe mem ber, 101, will be in condition of partial vac" chamber, 31, at the other side.

uum by reason of which it is referred to as vacuum trap.

\Vhcn the engine is stopped, causing the pump to be stopped, interrupting the suction by which the partial vacuum in the standpipe, 100, is caused, if there is leakage past the pump valves, 63 and 73, it may be understood that the fuel will tend to flow back from the carbureter feed pipe through the entire conduit and pump passages; and in the absence of the vacuum trap or other provision for limiting such flow, and retaining the fuel in the system ready to respond to demands of the engine when the latter is started, the system would be liable to be drained of fuel by such back flow.

The construction which comprises the vacuum trap operates to prevent such drainage of the system, as will now be described.

When the engine is stopped, the gasoline in the supply pipe, 54, tends to recede, which, tending to increase the vacuum in the-vacuum standpipe, 100, operates in fact as the valves leak to draw all gasoline from the liquid trapping chamber and passages therebeyond, including the pumping chamber. The liquid rises in the vacuum trap chamber a distance which is the measure of the vacuum in the vacuum trap and pipes, 100- and 54, above the level of the liquid upheld in the pipe, 54. Since the vacuum trap is exposed to atmospheric pressure through the leaking of the valves and the main tank from which the pipe, 54, leads is also exposed to atmospheric pressure, the degree of vacuum intervening in the line of communication to both said atmospheric pressure chambers will uphold the liquid to an equal height above the liquid levels in the respective liquid sources,-viz, the main tank at one side and the liquid trap The cross 'sectional area of the standpipe, 100, being many times that of the uniform cross sectional area of the pipes, 101 and 54, a rise of liquid in the trap chamber, 100, to a distance ot'say three inches above the governed level of the liquid trapping chamber, 31, will result in recession of the level in the pipe, 54, nearly the entire distance back to the main tank, that is, to reach a level three inches above the level of the liquid in the main tank. And this condition of levels and vacuum will be maintained while the engine stands idle. It will be observed that this condition is that the vacuum trap stalidpipe, 100, contains all the liquid which the leakage ot' the valves has permitted to recede from the pumping chamber and its inlet and discharge passages; and that the same is ready to respond at once to the first intake stroke of the piston when the engine starts, as promptly within a negligible degree, as if there had been no valve leakage and the liquid had remained in the pump passages.

It will be seen that the liquid trapping chamber, 31, must have an atmosphere vent,

and the same is shown at 32, and this atmosphere vent must of course be, as shown, a substantial distance above the highest level which may be reached by the liquid in the liquid trapping'chamber. Inasmuch as the main supply tank, C, may be ver vated above the level of tli paratus and the carbureter when the vehicle is on descendin grade, so that there will be a tendency of die fuel to flow by gravity to the pumping apparatus and the carbureter, it is necessary to provide against floodin theliquid trapping chamber, 31, under tiese circumstances in order to prevent the liquid from escaping through theatmosphere vent, 32; andfor this purpose the float, 90, has its stem, 91, which carries the valve, 92, for the purpose above described, provided also with a valve, 93, below theport, 55, and at such distance that said valve will be seated upwardly, closing said port upon the rise of the float due-toliquid filling the chamber, 31, to alevel sufficiently below that of the atmosphere vent, 32, to avoid escape of the liquid throughsaid vent port. To prevent liquid splashing out through the atmosphere vent port, 32, there is advisedly provideda splash guard d isk,34, in the chamber, 31, the same being conveniently made as a sheet metal stain in g dimensioned for fitting in the chammaterially elee pumping apher tightly enough to require no other secure ment.

The operation of the pump by an engine cam, as shown in the drawings, will nowv described:

lhe piston is positively actuated in itsintake stroke by the engine cam, D, in them:-

tive phase of the cam cycle, through the methe upper end of the cavity offthe casing member, 30, which cavity constitutes also the liquid trapping chamber, 31.

The same spring, 72, may under some running conditions serve to cause the lever member, E, to follow the cam in the idle phase of the cam cycle; but this function is provided for by a spring, 7 5, housed in a hood, 26, on the upper side of the casing member, 40, and reacting between the top of said housing and a cup sleeve, 27, -mounted slidingly said housing and in an aperture of the casmg 40, over which the housing is mounted, the bottom of thecup sleeve being pressed by the spring, 75, against a projection, E, which extends from the upper edge of the lever member, E, at the opposite side of the fulcrum of the lever from the end, E, which bears u on the cam, D, and is held thereagainstb the reaction of the spring, 75.

It will e understood upon considering the construction that in the active phase of the cycle of the cam, D, the lever members, E and F, operate as a rigid lever by reason of the co-operation of their respective stops, e and f, and that in the positive stroke communicated by the connection described to the pump piston, being the intake stroke of the latter, the sprin 72, is compressed for storing up energy or givingthe piston its return or feeding stroke, which will be shorter or longer according to the varyin fuel requirement of the engine, and that or the variation of this feeding stroke, provision must be made for lost motion between the piston and the end, E of the lever member, E, which, by the reaction of the spring, 75, is caused to follow the cam in its idle phase. And such provision is made by the two-membered lever construction with the two members, E and F,

having pivotal action relative to each other in the active phase of the cam which gives the piston its intake stroke, the stops, e and f, separating in the lost motion phase, and cooperating for causing the two lever members to move as one in the active phase of the cam.

The forms shown in Fi ures 4, 5 and 6 present a modification conslstin in that the duct from the drain port of t e trapping chamber intersects the inflow passage leading to the pump intake valve, and that the float stem extending past the intersection, carries a cut-off valve seating below the intersection so as to cut off infiow to the pump antecedent to the pump intake valve, and said valve (corresponding to the valve, 93, of

the previous form) being seated when the liquid trapping chamber is filled to a predetermined height, cuts oil the flow not only from the supply line, but also to the pump.-

The purpose of this feature of construction is that when the main supply tank is elevated above the level of the pump and carbureter, as when the vehicle is on a descending grade, and the engine is not running the flow of fuel by gravity both to the pump and to the trapping chamber is prevented, and flooding of the apparatus which would otherwise result, is avoided.

Figures 4, 5, and 6 present other minor modifications; and the construction of these figures will now be described.

Referring to Figures 4, 5 and 6: The lever members. M and N, corresponding to E and F of Figure 2, present transposition of the co-operating stops, the lever member,

M. having the stop pin, m, corresponding to e of Figure 2, and the lever member, N, has the stop shoulder, n, corresponding to e of chamber, and from the lower side of the boss,

111, which corresponds to the boss, 50, of Figure 2; and in said downwardly extending boss, 110, the inflow passage, 52, is continued downwardly, as seen. at 52*, alongside the duct, 112, which corresponds to the duct, 55 of Figure 2, leading from the drain port, 113, corresponding to the drain port, 55, of Figure 2, and said downwardly extending portion, 52*, of the inflow duct opens into the duct, 112, below the point at which said duct, 112, communicates by a port, 114, with the pump intake valve fitting antecedent to said pump intake valve; and the downwardly facing valve seat, 112, is provided in said duct, 112, belowthe communication by way of the ort, 114, with the intake valve. And the oat stem, 91*, extending down through the port, 114, carries below said port a valve, 93*, corresponding to the valve, 93, of Figure'2 which is adapted to seat ufpwardly at said valve seat, 112, cutting off in ow to the pump chamber as well as to the liquid trapping chamber when the rise of liquid in the trapping chamber to the predetermined level lifts the float for seating said valve, 93*.

The parts and features of Figures 4, 5 and 6, which are substantially identical in form with corresponding parts and features of the previous figures, are indicated by the same reference letters or numerals and require no further description.

Upon considering the operation of the construction shown with respect to the co-operation of the auxiliary or liquid-trapping chamber, 31, and the vacuum trap comprising the stand pipe vacuum chamber, 100, and the fuel inflow pipe, 101, upon the stopping of the engine causing stopping of the pum when the engine valves are leaky so that the fuel tends to flow back toward the main fuel supply tank, it may be seen that the degree of vacuum in the vacuum trap stand pipe, 100, being that which is adequate for lifting the fuel from the main tank to the discharge at'the upper end of the fuel stand pipe, 101, will be satisfied by responsive flow from both sources, viz., the auxiliary or liquid-trapping chamber, 31, and the main fuel supply tank, both under atmospheric pressure; and, except as negligibly affected by difference of friction and inertia of the liquid fuel, will cause the liquid level in the vacuum trap stand pipe, 100,'to be as much above the governed level of the auxiliary chamber, 31, as the level to which the fuel recedes in the pipe, 54, as above mentioned,

is above the liquid level of the main sup ly tank; and that these substantially equal. istances will be each a fraction of theoriginal fuel lift from the main tank to the discharge upper end of the pipe, 101, by reason of the originally evacuated space of the stand pipe, 100, becoming occupied by fuel fed thereto by gravity flow from the auxiliary chamber, 31, and the fuel line therebeyond to the carbureter. The ,value of this fract1on will vary with the construction and mounting on the car with respect to the relative elevation of the main fuel tank, carbureter and fuel pump; but a practical come mercial construction will allow for considerabl wide variation of these conditions, by ma 'ng the stand pipe, 100, at least twice the height of the auxiliary chamber, 31, and its cross-sectional area for fiuid capacity from four to six times that of the fuel pipe, 101.

I claim: v

1. A pumping apparatus for supplying fuel to an internal combustion engine comprising a -pum ing chamber and a pum ing member operating thereon, the chamber aving inflow and outflow connection with the fuel supply line leading from a fuel source, an out ow connection 1 leading to the carbureter; an auxiliary chamber having extent above the level of the pumping chamber and having communication with the outflow passage of the pumping chamber, and a drain port communicating with the inflow passage of the pumping chamber, a normally seated valve controlling said drain port, and a float in said auxiliary chamber connected with said drain port valve for opening the same upon accumulation of liquid in said auxiliary chamber above a predetermined level for controlling the level of said auxiliary chamber; a vacuum trap on the fuel supply line anterior to the drain port of the auxiliary chamber, said vacuum trap having upper part fuel inflow connection with the fuel supply line from the fuel source, and at the lower part a fuel outflow connection with the fuel line toward the pumping chamber and carbureter, said outflow connection being located at a substantial distance below the governed level of the auxiliary chamber, and said vacuum trap chamber having substantial liquid capacity above said outflow connection and below the governed level of the auxiliary chamber and additional capacity continuous with the first-mentioned above said governed level and below the level of the fuel inflow connection; said additional capacity being in excess of the fuel capacity of the inflow pipe back to the liquid level of the fuel source 2. An apparatus for feeding fuel to a place for supplying the carbureter of an internal combustion engineconsisting of a piston pump comprising a casing containing a ber positioned with respect to t at the P pumping chamber with inflow and discharge passages and one-way flow valves controlling said passages for pump intake and discharge, the pumping chamber being connected for discharge to a fuel line leadin directly to the iston reciprocating in the pumping chamer, and means for flooding the pumping chamber comprising a liquid traplping chame pumping chamber for delivering liquid by avit flow into the pumping chamber at tlib si e of the piston opposite the pump intake, said liquid trapping chamber being arranged to derive liquid from the discharge line 1n the feeding stroke of the piston and having a passage of communication with the pump intake; a float inthe trapping chamber and a valve operatively connected with the float located in the last mentioned passage ata point therein for cutting off communication with the inflow passage to the pumping chamber.

3. An apparatus for feeding fuel to a placefor' supplying the carbureter of an internal combustion engine consisting of a piston pump com rising a casing containing a pumping cham r with inflow and discharge passages and one-way flow valves controlling said passages for pump intake and discharge, t e pumping chamber being connected for discharge to a fuel line leading directly to the place for carbureter supply, a piston reciprocating, in the pumping chamher, and means for flooding the pumping chamber comprising a liquid trapping cham ber positioned with respect to the pumping chamber for delivering liquid by gravity flow into the pumping chamber at the side of the piston opposite the pump intake, said liquid trappin chamber being arranged to derive liquid rom the discharge line in the feeding stroke of the piston, and having a assage of communication with the pump intake, a float in said trapping chamber and a valve operatively connected with the float for simultaneously cutting ofi communication of the inflow passage both with the pumping chamber and with said trapping chamber.

4:. An apparatus for feeding fuel to a place for supplying the carbureter of an 1nternal combustion engine, consisting of a piston pump comprising a casing containing a pumping chamber with inflow and dis charge passages and one-way flow yalves controlling said passages for pump intake and discharge respectively, the pumping chamber being connected for discharge to a fuel line leading directly to the place for carbureter supply; a piston reciprocating vertically in the pumping chamber and means for flooding the pumping chamber by gravity flow of fuel thereinto to mamtain the piston liquidsealed, said means place for carbureter supp y, a

5. An apparatus for feeding fuel to a place for supplying the carbureter of an internal combustion engine, consisting of a piston pump comprising a casing containing .a pumping chamber with inflow and discharge passages and one-way flow valves controlling said passages for ump intake and discharge respectively, t e pumping chamberbein connected for discharge to a fuel line lea in directly to the place for carbureter supp y; a piston reciprocating vertically in the pumping chamber and means for flooding the pumping chamber by gravity flow of fuel thereinto to maintain the liquid piston liquid-sealed; said means comprising a trapping chamber located above the piston and in communication with the inactive face thereof, and a passage branched from the pump discharge passage beyond the discharge valve and leading for discharge into said trapping chamber, said trapping chamber having liquid flow connection with the pump inflow passage ante- 'ccdent to the pump intake valve, a valve controlling said flow connection and a float in the trapping chamber operatively connected with said valve for openin the same upon rise of liquid in the trapping chamber beyond a predetermined level.

6. An apparatus for feeding fuel to a place for supplying the carbureter of an internal combustion engine consistingof a piston pump comprising a casing containing a pumping chamber with inflow and discharge passages, and one-way flow valves controlling said passages for pump intake and discharge respectively, the pumping chamber being connected for discharge to a fuel line leading directly to the place for carbureter supply; a piston reciprocating vertically in the pumping chamber, and means for floodin the pumping chamber by gravity flow of uel thereinto to maintain the piston liquid-sealed, said means comprising a trapping chamber located above the pumping chamber in communication with the inactive face of the piston, the fuel inflow passage to the pumping chamber having connection consisting of a passage opening for communicating with said trapping chamber at a point above the piston at the limit of its intake stroke, the last mentioned passage having two valves for controlling the fuel flow therethrough opening respectively for inflow and outflow; and a float in the trapping chamber operatively connected with both valves for seatin them respectively upon the liquid .5 content 0 the trapping chamber passing predetermined high and low limits res ectively.

7. A pumping chamber for supp ying fuel to the carbureter of an internal combustion engine comprising a casing having a pumping chamber and a pumping member operating therein, said chamber having inflow and outflow passages, valves controlling said passages respectively for one-way flow through the pumping chamber toward the carbureter; an auxiliary chamber proximate to the pumping chamber positioned and arranged for communicating by gravity with the pumping chamber at the inactive s1de of the pumping member having flow communication with the inflow passage of the pumping chamber anterior to the valve of said inflow pas'sa e and with the outflow passage, constituting t e discharge line, of the pumping chamber subsequent to the valve in said passage; whereb the fuel may be pumped in endless circuit through said auxiliary chamber, and means adjustable at will for variably restricting at least one of said communications of the auxiliar chamber for governing the pressure in said ischarge line to the carbureter.

8. A pumping apparatus for suppl ing fuel to the carbureter of an internal com us-.

tion engine comprising a casing having a pumping chamber and a pumping member operating therein, said chamber having inflow and outflow passages and valves controlling said passages respectively for one-way flow through the pumping chamber toward the carbureter; an auxiliary chamber proximate to the pumpin chamber and arranged for communicatln g y gravity with said pumping chamber at the inactive side of the pumping member, said auxiliary chamber having flow communication with the'inflow passage of the pumping chamber anterior to the valve thereof and with the outflow passage of the pumping chamber, constituting the discharge line to the carbureter, subse uent to the valve of said outflow passage; w ereby the fuel may be pumped in endless circuit through said auxiliar chamber, and a valve in the communication of the outflow passage with the auxiliary chamber adjustable at will for variably restricting the communication of the outflow from the pumping chamber with the auxiliary chamber, for governing the pressure in the discharge line to the carbureter.

9. In the construction defined in claim 4 a

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