US1329781A - Pressure-feed device for internal-combustion engines - Google Patents

Description

E. M. 0. LEPERE.

PRESSURE FEED DEVICE FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED DEC. 23, I918.

1,329,781 Patented- Feb. 3, I920;

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EUGENE MARIE GEORGES LEPERE, OF PARIS, FRANCE, ASSIGNOR'TO WEBB JAY, OF CHICAGO, ILLINOIS.

PRESSURE-FEED DEVICE FOR INTERNAL-COMBUSTION ENGINES.

accompanying drawings, forming a part thereof. I

The purpose of this invention is to provide an improved construction for feeding liquid fuel to the carbureter of an internal combustion enginefrom a supply tank at a lower level than the carbureter. It consists in the elements and features of construction shown and..described, as indicated in the claims.

In the drawings: 7

Figure 1 is a vertical axial section of a structure embodying this invention, the same being shown in connection with the main fuel supply tank to which it is appended.

Fig. 2 is a top plan View of the same.

Fig. 3 is a detail section at the line, 33, 011 Fig. 2.

In the structure shown in the drawings, 1 represents the main fuel supply tank for an internal combustion engine, not shown, but of which it may be understood that the car' bureter is at a higher level than the said tank, 1. Appended to the tank, 1, in position to be supplied by gravity flow therefrom is an'auxiliary receptacle comprising a chamber, 2, which directly receives the liquid fuel supply by gravity from the tank,

1, and a second chamber, 3, which receives the liquid fuel from the chamber, 2. It will be understood that the tank, 1, has an atmosphere inlet aperture at; the top so that the liquid therein is exposed to atmospheric pressure and is free to be dischargedby gravity through any opening at the lower part, and at such opening there is protruded a discharge nipple, 1, which extends up in the tank, 1, a short distance so as to leave a trap space at the bottom for accumulation of sediment and water. The pipe, 4:, extends down into thechamber, 2, of the auxiliary receptacle, and the discharge mouth therein is controlled by a check valve, 5, opening for discharge of the liquid into the chamber,

2, and seating in the opposite direction to I prevent return of the liquid or pressure Specification of Letters Patent;

Application filed December 23, 1918. Serial No. 268,042.

from the chamber, 2, into the tank, 1. The chamber, 2, discharges into the chamber, 3, through a fitting, 7 supplied with a check valve, 8, similar to the check valve, 5, and operating similarly to prevent return of the liquid from the chamber, 3, back into the chamber, 2. The chamber, 2, is constructed for being suspended inside of the chamber,

,3, both said chambers having at their upper ends outwardly turned flanges, 2 and 8, respectively, lapping upon each other with opportunity for the interposition of packing to make the joints liquid-tight, said flanges serving as a means for securing both cham' bers together to the cap member, 10, which is a casting having at its upper end a flange, 10 by means of which it may be secured to the bottom of the tank, 1. In the cap member, 10, there is provided an atmosphere inlet passage, 12, opening at the port,

the cap member, 10, and having preferably connected at that point a pipe, 13, which extends upwardly to any desired height alongside the tank, 1, for safety against overflow or discharge of liquid through theatmosphere inlet in case of any derangement of the apparatus which in its ordinary operation would prevent such an overflow. In the cap member, 10, there is also provided a passage, 15, opening at the port, 16, through the cap into the top of the chamber, 2, said passage being extended for emerging at the edge of the cap member, 10, and there connects to a pipe, 17, leading from any 12 into the top of the chamber, 2, the other end ofsaid passage opening'at the edge of source of super-atmospheric pressure, represented conventionally by the tank, 18, which may be understood to be a reservoir of compressed air interposed in a line leading to an alr-compressing pump, not shown. In the passage, 15, there is interposed a Venturi' for produclng a snap action in a manner which is familiar. A float, 31', in the chamber, 2, carried on'an extended arm, 33, of the lever, 28, operates in a familiar manner to open the valve, 26, and close the valve, 25., when the float is lifted to a predetermined point by the rise of the liquid in the chamber, 2, and to reversely actuate said valves, closing the valve, 26, and opening the valve, 25, when by the fall of the liquid in the chamber the float descends to a predetermined point.

The operation of the structure above described is as follows:

The main tank, 1,- being supplied with liquid and the auxiliary device being empty,

' the valve, 26, is closed and the'valve, 25,

opened, the float being at the lowest position which it can reach in the chamber, 2; and liquid will flowfrom the tank, 1, into the chamber, 2, causing the same to be filled because the liquid cannot flow out of the chamber, 2, into the chamber, 3, on account of super-atmosphericpressure in the chamber, 3, holding the valve, 8, closed. When the chamber, 2, is filled with liquid to a predetermined point,- lifting the float high enough to cause the snap action of the valve-operated mechanism to occur, reversing the valves, seating the valve, 25, and opening the valve, 26, atmospheric escape being cut off and the super-atmospheric pressure admitted past the valve, 26, will cause the valve, 5, to be closed, preventing the further flow of liquid from the tank, 1, into the chamber, 2, and at the same time the pressure in the chamber, 2, with that being equalized previously ex: isting in the chamber, 3, the liquid in the chamber, 2, will fall by gravity past the valve, 8, into the chamber, 3, until the liquid level in the chamber, 2, falling to a predetermined. point, causes the float by its descent to operate the valve mechanism and actuate the valves for reversing them, and restoring the original conditions under which the liquid will cease to flow out of the chamber, 2, intothe chamber, 3, and will begin to flow again from the tank, 1, into the chamber, 2. The effect of opening the valve, 26, and closing the valve, 25, has been referred to as equalizing the pressure in the chamber, 2, which had previously existed in the chamber, 3; but it is the intentionof the construction described that the first effect, which is due to the employment of the Venturi throat-piece, 20, in the superatmospheric air inlet passage, 15, shall be -to withdraw fluid through the restricted port, 22, from the chamber, 3, simultaneously -with the admission of super-atmospheric pressure .to the chamber, 2. This happens because of the high velocity of theair current through the Venturi throat when the valve, 26, is first opened, and when the maximum difference exists between the pressure in the chamber, 2, and that derived'from the v The source of super-atmospheric pressure. need for thus reducing the pressure in the chamber,-3, while it is being increased in the chamber, 2, so that there shall not be exact equalization of pressure between the two chambers but at least some excess of pressure in the chamber, 2, over that in the exactly equal, this would result in an'excess of force tending to hold thevalve seated,

which would require a certain head of liquid in the chamber, 2, to overcome, in order that the valve might open for discharge; and its opening would thereby be delayed, causin the operation of the apparatus to'be s uggish. This is prevented by the expedient noted, consisting in the restricted port'for the withdrawal of superatmospheric pressure froml the chamber, 3. When the valve, 8, has opened and the flow of liquid has commenced from the chamber,

2, t0 the chamber, 3, or when without the opening of that valve the super-atmospheric pressure from the source is fully operative in the chamber, 2, the pressure in the two' chambers would be'equalized through the restricted port, 21, because at that stage there will be noappreciable current of air passing through the Venturi, and at least no velocity which would cause any reverse current through the port, 15, as the restricted port would at all times afford sufiicient access for 'for maintaining the fuel supply to the carbureter float chamber, or for directly discharging in the mixing chamber in certain forms of the carbureter.

I claim 1. In a liquid supplying system, in combination with a source of liquid, a chamber to which the liquid is delivered from said 100 employment of the Venturi throat-piece and r source; a non-return valve in the communication by which the liquid is delivered to said chamber; a source of super-atmospheric pressure; connections therefrom to said chamber; means Operated by change of liquid level in the chamber for interrupting the access of the super-atmospheric pressure thereto; a second chamber into Which the first chamber discharges, said second chamber having uninterrupted communication with the source of super-atmospheric pressure, and a non-return valve controlling the discharge communication fromthe first chamber into the second. a r

2. In the structure defined in claim 1, foregoing, means in the super-atmospheric pressure communication to thesecond chamber for relieving the pressure transmitted therethrough. when the super-atmospheric pressure communication of the first chamber is open.

3. In the structure defined in claim 1, foregoing, the super-atmospheric pressure com-,

port leading from a point inward from the constriction of said throat for communication with the second chamber; whereby the second chamber has restricted communi-.

cation with the source of-pressure and the pressure therein which is relieved by the free flow of the super-atmospheric pressure current through the Venturi throat when the pressure communication with the first chamber is open.

In testimony whereof I have hereunto set my hand at Chicago, Illinois, this 17th day of December, 1918. I

EUGENE MARIE GEORGES LEPEEE.

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