US1865624A - Fuel pump - Google Patents

Description

July 5, 1932. I FRELIN 7 1,865,624

I FUEL PUMP Filed Jan. 7, 1932 5 Q g I g I I 1i: -K i z 10% P 4 %D Z Z f y 2 3 /J 3 I I vg 2 j p E/ n 'z y gfim HIS ATTORNEY in art ointed out hereinafter.

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Patented July UNITED STATES PATENT. OFFICE I FBITJ'OF FBELm, OF PHILLIPSIBURG, NEW JERSEY ASSIGNOB 'I.O INGEBSOLL-RA NI COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY Application fled January 7, 1982. Serial No. 585,290.

Still another ob ect is to adequately seal the by-pass valve mechanism and thus prevent leakage of fuel to the exterior of the casing.

Other objects in part obvious and gure in the drawing accompanyin this specification is a sectional elevation of a fuel pump equipped with a by-pass valve constructed in accordance with the practice of the invention.

Referring more particularly to the drawing, A designates, in general, a fuel pump comprising a casing B havin a bore C for the reception of a guide bushing D wherein is arranged a plungf; E. 7 V

The pumping c mber F, wherein the plunger E reciprocates, is provided with an enlarged chamber G from which leads a discharge passage H having a conduit J connected thereto pumped by the plunger E may ,flow to a desired destination, as for instance, to a distributing device of an internal combustion en e.

rran ed between the pumping chamber F and t e discharge passa 1s "a valve guide K which is held fixe y a hollow nut L threaded into the caslngiB to seat against an end of the valve guide A passage 0 in the valve guide K afiords com munication between the pumping chamber F invention is to enablethrough which the fuel in position by and the discharge passage H and also serves to guide the stem P of a valve Q of the poppet type which cooperates with a seating surface R at the discharge end of the passage 0 for controlling communication between said passage and the discharge passage H. A spring S is disposed in the discharge passage H to act with one end against the casing B and with its other end against the valve Q for returning the said valve to its seat R.

On the stem P of the valve Q are the usual 'de ribs T between which the fuel-pumped y the lunger E may flow to act agamstthe valve for opening it.

Within the casing is a supply passage U vwhich may lead from a reservoir (not shown) to the pumping chamber F for conveying liquid fuel thereto. The passa U is provided with an enlarged portion l to accommodate a guide member W having a bore X therein and the discharge end of which terminates in a seating surface Y for a poppet valve Z. The valve Z is normally held closed by a spring 6, interposed between the valve Z and the casing B, and has a stem 0 which extends into the bore X. On the stem 0 are longitudinally extendin ribs (1 to cooperate with the bore X for gui ing the valve.

In its essential respects the pumping 'device so far described my be substantially like that disclosed in United States- Patent No. 1,577,590 granted to G. J. Rathbun,

March 23, 1926. The present structure, how-- ever, differs from the aforesaid patent in the respect that the valve which controls the supply passage U operates independently of the plunger E, in the present instance the valve Z being unseated by the pressure of the fuel flowing from storage to the pumping chamber F. The plunger E, hdwever,

patent. It reciprocates continuously so that fuel is alternately drawn into and discharged is intended to be actuated in the manner-outlined in the from the pumping chamber F as a continuous operation.

With the plunger E connected to be actuated as in the aforesaid pate'nt its discharge or compression stroke willbe of considerably longer duration than the period during which fuel is injected into the engine. In order to nullify a portion of the pumping stroke of the plunger E in excess of that required for charging the engine cylinder means are 'provided for by-pass ing a portion of the fuel being pumped. To this end the casing B is provided with a bore '6 having a threaded outer end f and a reduced portion 9130 form a shoulder h. The lower end or reduced portion of the bore 6 in the present instance communicates directly with the inlet passage U through a pa$agej which opens into the lnlet passage u between the valve Z and the source of supply.

Disposed within the bore e is a valve 'de 7: havmg a flange 0, an end surface or sill ulder p 0 which is adapted to seat upon the shoulder h or, as illustrated, upon a gasket q idnteliposed between the flange o and the shoul- Seated upon the opposite or upper end r of the flange o is a packing member s which is suitably compressed against the surface of the bore 6 by a hollow bushing t which encircles the guide member k and is threaded into the threaded end f of the bore e to hold the guide member k'secure'ly in position and to adeiauately seal the bore e at opposite ends of the ange o.

Extending longitudinally through the guide member I: is a bore u for the accommodation of a sleeve valve '1; having a stem w which extends upwardly through the bore u and carries a head as. A spring 3 acts with one end against the lower surface of the head :0 and with its other end against a shoulder 2 on the exterior of the guide member is.

In the lower portion of the sleeve valve '0 is a longitudinally extending passage 2 which opens at its lower end into the reduced portion 9 and communicates with its upper end, through radial passages 3, with an annular groove 4 in the periphery of the valve '0. In the guide member k is an annular groove 5 which communicates with the pumping chamber F through a passage 6 in the casing B, and with the bore a through a passage or passages 7 in the guide member is.

The devices whereby the sleeve valve '0 may be actuated are illustrated as being like. those employed in the aforesaid patent. These devices comprise a rod 8 which may be actuated a well known manner and is connected at its upper end to a lever 9 having a curved surface 10 against which acts a shiftable fulcrum 11 for determining the degree of opening of the sleeve valve a. The lever 9 is also provided with a screw 12 threaded into theend of the lever to act upon the head a: for depressing the valve '0.

The manner in which the lever 9 and the fulcrum 11 operate to actuate the valve '0 is well known. It may, however, be pointed out that the fulcrum is intended to be shifted by means of a centrifugal governor, in a manner well understood, so that when the fulcrum is rocked towards the left hand end of thecurved surface 10, a position which it will assume when the engine is operating at low speeds, the valve '0 will be onlyslightly depressed to estabish'communication between the annual groove 1 and the passage 7. In such case fuel under pressure will then escape through these channels andthrough the relief passage 2 into the supply passage U.

Upon acceleration of the engine to whichthe pumping device is connected the fulcrum 11 will be shifted in the direction of the rod 8 and the valve *0 will, in consequence be opened to wider limits, thus passing a greater proportion of the fuel from the pumping chamber F to the supply passage U.

In practice the present invention has been found to be unusually efiicient. The valve guide k may be adequately sealed against leakage such as commonly occurs in devices of this character. An addltional advantage of this form of construction is that the by-pass valve is not constantly subjected to the jars resulting from the thrusts of the plunger E and which are, of course, transmitted by the fuel in the pumping chamber to the elements adjacent thereto.

I claim:

1. In a fuel pump, the combination of a casing havin a pumping chamber and supply and disc arge passages communicating therewith, valves to control communicationbetween the passages and the chamber, a plunger in the chamber to pump fuel through the discharge passage, a guide member in the casing having a bore and a passage to afford communication between the bore and the pumping chamber, a sleeve valve in the bore having a relief passage in constant communication with the supply passage, and means for actuating the sleeve valve to establish registry between the relief passage and the pumping chamber for bypassing fuel from the pumping chamber to the supply passage.

2. In a fuel pump, the combination of a casing having a pumping chamber and supply and discharge passages communicating therewith, valves controlling communication between the passages and the chamber, a

lull r in the pumping chamber to pump el t rough the discharge passage, a bore in the casing and in communication with the pumping chamber, a shoulder in the bore, a guide member in the bore to seat upon the shoulder and having a bore therein and a passage to afiord communication between the bore and the pum ing chamber, said guide member having a ange seating with one end upon the shoulder, a packing member on the other end of the flange, a sleeve threaded into the casing to compress the packing member between said sleeve and the flange, a spring pressed sleeve valve in the guide member havlng a relief passage in constant communication with the supply passage, and means for actuating the relief valve to establish communication between the relief passage and the pumping chamber for by-passing fuel from the pumping chamber to thesupply passage.

, In testimony whereof I have signed this specification.

FRITJ OF FRELIN.

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