US1919040A - Fuel pumping device for internal combustion engines - Google Patents

Description

July 18, 1933- E. A. RocKwELl. f 1,919,040

FUEL PUMPING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed July 2. 1928 Patented July 18, 1933 `PATENT OFFICE.;

EDWARD A.. BOCKXNELL, OF LONG ISLAND CITY, NEW YORK FUELy summe Dnvlcn AFoa INTERNAL comBUsrIoN ENGINES Application med myu 2, icas. serial No. 289,594.

The purpose of this invention is to. provide an improved construction of a pumping device forl supplying fuel to the carbureter of an internal combustion engine. It consists in theelements and features of construction shown and described as indicated in the claims.

. cam Within adj acent an aperture thereof in Mechanically driven fuel pumps liave been designed for feedin fuel at a constant presoperated through a constant stroke reciprocable lever carried by the'pump casing arranged to have a protruding armthereof. in thrust enga ement with an en ine driven tionconnection between the other arm of the lever and a stem connected to the diaphragm.

- It is also old in apump construction, to use an interposed'spring in the 'operating connection which, upon yielding, will limit the discharge impulse su ment. 3

It is a purpose of the present invention to provide a fuel pump construction in which the diaphragm is 'ven a Vpositive suction stroke and a resiliently limited, discharge stroke throu h the use of an inte osed compression sprmg and to additionav y' employ a second compression spring acting upon the jected to the pumping eleoperating lever in' such a manner as to maintain the engine driven cam for its full stroke durm the inactive phase of the cam and arrange to produce the dscharge stroke of the pumping diaphragm by acting through the inter-- posed compression spring. .In the operation Q fa pump of this type, the suction will alion` required to draw the fuel frome engine casing wit a lost mover in thrust engagement with the;

the disways be produce/d positively while compression spring and resilientl limited by a second compression spring. t is also desirable'to so arrangesth'e discharge limiting spring that the friction of the part guid' charge will be produced resiliently by a irst ed by the pump casing will not detract from l the force of the limiting spring.

In the drawing: f Figure 1 is a diagrammatic view showing the location of the pumping device with re.

spect to the engine 'carbureter and the fuel source on 'an automobile.

Figure 2 is an axial section of the pumping device, this section extending -to include the adjacent portion of the engine body upon which the pumping device is mounted.

In the construction` shown in the drawing,

the engine'body is indicated at A, the carbureter at B, the fuel .source at C, andl the pumping device in its entirety at D.

The pumping device comprises a casing structure consisting ,of two members," and 30. The member, 20l is adapted to be mount- Y ed upon the body of the engine to be served, as seen at 20, having its cavity communieating with the cavity, a, of the engine body. Said member, 20, and the member, 30, are formed with mated iianges, 20? and 30h, encompassing cavities, 20 and 30, of said casing members respective-ly, adapted for clamping between them aflexible diaphragm, 40, which constitutesa mov-` ing wall of the chamber formed by /the cavity, hereinafter referred to as the pumping chamber.. 4Said pumping chamber 1s connectedv for re ivin'g fuel supply from the fuel source by a condu1t,v50, whlch as shown comprises a sediment cup, x, f well understood construction not a part of this invensaid flanges being tion and requiring no specific description,

in which conduit, an as shown in the outfiow passage, 505', of the sediment cup,-there is interposed a check valve, 50, opening for iniiow to the pumping chamber and seating against lreverse ow. The pumping chamber is further connected by a pipe, ,60, leading to the carbureter in which there is interposed a valve, a, opening for outflow from the pumping chamber and seating against re- "45 chamber-enlarging verse iow. For operating. the diaphragm, 40, to flex it alternately in the directions for enlarging and reducing the pumping chamber, said diaphragm 's provided with a two- 5 membered stem, of wllich one member, 70, is positively connected to the diaphragm at the center thereof where said stem serves also for clamping a central area of the diaphragm between disks, 41 and 42, the clamping being effected by a nut, 70, screwed onto the end of the stem member, 7 0, above the disk, 41.

The other stem member, 80, is tubular, that is, axially hollow, and is afforded slide bearing at 20d in the casing member, 20. This stem member is connected at its lower end, as

seen at 80, with the inner end of a lever, 90, fulcrumed at 90a', in the casing member, 20', and protruding from the casing member into the engine 'casing where its terminal,=,`90b, is positioned for .actuation by a cam, 10.0, on a rotating shaft, 101, of the engine. The stem member, 70, is telescoped within thefstem member, 80, the latter havin inwardly struck stop lugs, 80, past whic the lower end of the stem member, 70, protrudes,and

Hbelow which said stem member, 70, is furnished with a stop nut, 7 0b, co-operatingwith the lugs, 80a, of the stem member, 80, for limiting the extension of the total rstem consisting of said two members. Within the stem member, 80, and aroundthe stem member, 7 0, there is positioned a coil spring, 7 5,y

` which is initially conditioned by compression for reacting at its upper end against the under side of the diaphragm, 40,'and at its lower end against the stop lugs, 80, for holdlng the two-membered stem extended to the limit determined by the co-operating stops, 80 and 70h.

'40 LIt wilLbe understood from the foregoing description that the lever, 90, is actuated positively by "the cam, 100, in the direction for iiexing the diaphragm, 40, downwardly, that is,for giving said diaphragm itspumpingmovement; and` that for communicating t is pumping chamber-enlarging movement, the two-meihbered stem is positively actuated in the direction for extending theI stem to the limit Vdetermined by 5 0 the co-operating stops, 8l)EL and-7Gb, to which limit however, the stem Ais already extendedI by the reaction of the spring, 75, conditioned in the assembling of the parts by compression .for thusl reacting with predetermined force; 95 so that in the chamber-enlarging'l movement ofthe diaphragm the two-membered stem operates as a rigid unit, its two members and the .spring which reacts between them for holds ing the/stem extended being all moved togeth er positively .by the positively actuated lever, l90. y

y For giving the lever, 90, ret'urn movement there is provided a spring, 95, seatedin a cap, 20?, iiemovablysecured at the lower t end of the casing member, 20, `and having at its upper end a-cap, 95, for seatin .a downwardly extending proj ection90", o the lever, 90, said spring being conditioned by compression for normally reacting upwardly against the arm 'of the lever which engages the diaphragm stem, with predetermined force in l excess of .that needed to give the diaphragm its chamber-reducing movement for feeding the fuel to the carbureter. For accommodating the arcuate movement of the leverl at the end which engages the diaphragm stem, the lever is slotted, as seen at 90d, for engaging the pivot pin, 80d, by which it is connected to the sleeve member, 80. 4

From the foregoing description it may be understood that the spring, 95, is conditioned by compression for reacting with greaterforce than the spring, 75, vwhichnormally holds the two-membered stern extendedto the limit of the stops; but that the force with which the diaphragm performs its chamberreducing fuel feeding movement is determined by the reaction for which the spring,

75, is conditioned by its initial compressionl of the force by which the fuel is fed l-to the carbureter.

I claim: y

1. In`a pumpin .device for supplying fuel to an internal com ustion engine, a pumping element yand operating connections theretov comprising a lever arranged for positive actuation 1n one direction' only at one end, and

connections from the other end tothe pumpi ing member,'said. connections comprisingla sprin by-which the connections are normally exten ed to a predetermined limit, said eX- tension being in the direction fromthe'point of engagement of the levercorresponding to the feeding movement of the pumping member, and a spring reacting on the lever-in the opposite direction from its positive actuation and in the direction-for said feedingmovement of the pumpingI member, the' last menftioned spring being constructed for Jreactingl on the lever and through thelever on the first mentioned spring and through said lfirst menjtioned spring on the pumping'member, the

second mentioned spring being conditioned for reacting more forcibly than the first/mentionedy spring. f f 2. Afuel pump for internal combustion engines comprising' a pump casing adapted to b ejmounted on an engine casing-adjacent an aperture thereof, a y pumping diaphragm within said casingeadapted to cooperate with a pumping cham r on the upperside therehragm for limiting the discharge impulse iable discharge stroke of said spring, a second ported by the bottom' stem secured to said diating lever pivotally carried said lever having aneinof, a depending phragm, an opera y allowing a var through compression v compression spring sup of said pump' casmg and acting upwardly lever arm with an overcome said inducing the discharge through said interthe thrust enaid lever and the engine riven cam.

` EDWARD A. ROCKWELL.

by said pump casing, termediate ulcrum on said pump casing, said nged to extend into engage an engine tion connection between pending stem, positively to proroke of said dias positively moved an interposed springbetween tion connection and said dialever having one arm arra said engine casi driven cam, a lost mo vu on said last mentioned e ective force suicient terposed spring for pro stroke of said diaphragm posed spring and maintaining agement between s the other lever arm and said de said connection operating duce a positive suction hen said lever i by said cam, said lost mo lico-

Images