US1391230A - Vacuum fueir-feed device - Google Patents

Description

F.*G. WHITTINGTON.

VACUUM FUEL FEED DEVICE.

APPLICATION FILED IAN. 1o, 1921.

ptlltedsept. 20, 1921.

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FREDERIK G. WHITTINGTON, 0F CHICAGO, ILLINOIS, ASSIGNOR TO STEWART- WARNER SPEEDOMETER CORPORATION, OF CHICAGO, ILLINOIS, A. CORPORATION or VIRGINIA..

Application filed January 10, 1921.

To all whom t may concern.'

Be it known that LIFREDERTK G. WHIT- TINGTON, a citizen of the United States, residing at the city of Chicago, in the county of Cook and the State of Illinois, have invented certain new and useful Improvements in Vacuum Fuel-fl? eed Devices, of which the following is a specication, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved construction of vacuum fuel feed device for internal combustion engines for lifting the fuel from a tank lower than the engine carbureter to a source of supply which is positioned so as to supply the carbureter by gravity. It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings Figure 1 is a vertical axial section of a device embodying this invention, the position of the moving parts being that occupied when the vacuum chamber is being supplied with the liquid drawn from the low tank, not shown.

Fig. 2 is a section similar to Fig. l, showing the position of the moving parts outside when the vacuum chamber is emptied by gravity to the reserve chamber.

The drawings show only what is commonly known as the vacuum tank of the fuel feed device, with indications as to its connections with the main low tank, which is not shown, and with the engine intake manifold, which is not shownq and with the carbureter, which is not shown; these connections being familiar and their relation to the operatingv device lbeing well understood.

The device shown comprises a reserve or immediate supply chamber for the carbureter, indicated at 2; the vacuum chamber, 3, suspended within the chamber, 2, the top plate, 4, to which the chamber, 2, and the chamber, 3, are bothattached and by which they are rigidly united, and by which the vacuum chamber is closed at the top, the annular space, 5, between the two chambers being closed at the top by the overlapping flanges, 2a and 3a, of the chambers, 2 and 3, respectively, which flanges serve as means of securing the two chambers to the top plate, et, by bolts, 6. 7 is a liquid supply pipe Specification of Letters Patent.

Patented Sept. 20, 1921.

Serial 110.436,062.

vacuum chamber, so as to preventY delivering it on top of the fioat hereinafter mentioned. Connection for suction is made by means of a fitting, 12, screwed into the center of the top plate, 4;, connected by means of a pipe, 13, with the engine intake manifold, (not shown). Airinlet to the vacuum chamber is provided through a bushing or plug, 16, screwed into the top plate, 4, having a relatively large vertical aperture la, extending through it,v and a relatively small rightangle shaped air inlet duct, 16", extending in from the side and terminating at the upper end of the said bushingvor plug, whose said upper end is flat and constitutes a seat for a disk valve, 418, for which a chamber, 2l, is formed by means of a coupling, 19, flanged at its upper end for engaging the projecting flange, 20a, of a fitting, 20, which is screwed onto the lower downwardly projecting end of a'lateral and down-turned branch, 12, of the suction connection fitting, 12. Said branch has a duct, 12b, leading from the main suction duct of the'fltting as a branch or by-pass'andextending through and opening at the said down-turned end of said lateral branch, 123, and there communicating through the central duct, 20a, of the fitting, 2O` with the chamber 2l. F or a purpose hereinafter explained there is formed in the fitting, 20, a relatively small air vent passage, 20", terminating at one end at the Y outer surface of said fitting, and at the other end openingrthrough the Hat seat at the lower end of said fitting through which also the central aperture, 20, opens, so that both said central opening and said lateral vent passage are adapted to be closed by the disk valve, 1S, when said valve seats upwardly against the lower end of saidtting, 20, as hereinafter explained. The suction inlet at Vthe center of the vacuum chamber is controlled by the suction valve, 24, carried 0n the stem, 26, which carries a float, 25, operating upon rise of the liquid in the chamber to seat the suction valve, and upon fall of the liquid below a predetermined point to withdraw the suction valve from its seat against the suction tending to hold it thereon. Preferably the ioat has a range of movement along the stem, 26, between a lower stop, 26a, on which the float lodges at a predetermined low level of the liquid for adding its unbuoyed weight to that of the stem and valve, 24, for pulling said valve from its seat against the suction tending to holdV it seated, and an upper stop, 26h,4

against which the float is buoyed up at a predetermined high level for seating the valve, 211; and, also preferably, the weight of the valve and stem, 26, is Venough to pull said valve from its seat against suction somewhat greater than the lowest which is adequate to lift the liquid from the main tank; and there isV interposed between the iioat and said upper stop, 26h, a light compression spring, 29, whose resistance to compression is such that it is compressed enough for opening of the valve, 24, by something less than the full weight of said valve and stem,

so that as the float recedes under Vit yupon fall of the liquid level from the high point at which the ioat causes the seating of the valve, the spring expanding and reducing its upward reaction against the valve, the latter will be opened by the weight of the valve and stem, such opening occurring soonest when the suction is lightest and being delayed more as the suction is higher. This spring, 29, will be desirably so related to the weight of the valve and stem and to the suction with respect to stiffness and extent of expansion that when its resilient support of the valve is entirely withdrawn, 'leaving the full weight of the valve and stem available for opening the valve, such opening will occur against suction predetermined as high enough to cause reasonably prompt iilllng of the vacuum chamber. And when the suction is higher than a predetermined degree, the valve will not be 'opened Vuntil the float has fallen so far as to lodge on the lower stop, 26D, and the level of liquid has further fallen so that the unsupported weight of the float added to the weight of thel valve and stem will be adequate to open the valve against the high suction. The vacuum chamber, 3, discharges into the chamber, 2, through a fitting, 27, which at its upper end is provided with a guide, 27, for the lower end of the stem, 25, and an angle fitting, 28, screwed onto the lower end of said fitting, 27, the end of whose horizontal limb is preferably oblique, facing obliquely upward, and carries a check valve` 30. which is normally seated by gravity over the discharge end of the liquid passage, so as to be opened by the gravity flow of the liquid from the vacuum chamber into the chamber, 2. This construction is familiar in this art and is not upon starting the engine, suction through l the suction connection, 10, produces a partialV vacuum in the vacuum chamber, 3,

causing the liquid to be lifted through the pipe, 8, from the low level supply tank and discharged into the saidL vacuum chamber, gradually lifting the float, 25, and eventually at a predetermined high level, carry` ing the valve, 24, so'near to its seat at theY port of the suction connection, 10, that the suction operating therethrough `willA pull it to its seat, which will occur varyingly ac Y cording to the suction, occurring sooner,-' that is, at lower level of the l1qu1d,-when the suction 1s high, and a little later when the suction is low. During the process thus far described, the disk valve, 18, being initially lodged by gravity upon the seat at the upper end of the bushing or plug, 16, is held firmly to its seat by the suction resulting from the partial vacuum created in the vacuum chamber, 3, excluding air or atmospheric pressure form the vacuum chamber, 8, while said chamber is filling with liquid for lifting the float. Upon the closing ofv the suction valve by the rise of the float as above mentioned, the liquid will continue to iow in through the pipe, 8, until the vacuum in the vacuum chamber is reduced ta the'minimum which will balance the liquid column extending back to the low main sup ply tank. Meanwhile thesuction operating through the duct, 12b, in the lateral branch, 12a, of the suction connection, continuing unchanged during the reduction of vacuum in the vacuum chamberV operating through the duct, 16at0 hold the valve, 18, upon its seat, it results that at some point in the process of reduction ofv vacuum in the chamber, 3, lthe suction operating through the by-pass duct, 12b, while atmospheric pressure through the air inlet, 165, continues, lifts this valve 18, from its seat on the upper flat end of the bushing or plug, 16, admitting atmospheric pressure" will continue until the float, 25, withdrawl ing from the upper stop, 26a, permits the spring, 29, t0 expand and diminish its upholding action on the valve to such extent that the unsupported weight of the valve and stem exceeds the suction holding it on its seat, or in case the suction is inadequate to sustain the entire weight of the valve and stem, then until the float has so far fallen as to lodge upon the lower stop, 26h, and become unsubmerged s0 as to add enough of its weight to the weight of the valve and stem to pull the valve olf its seat against the high suction. The opening of the valve admits full suction to the vacuum chamber, 5, which will operate immediately to seat the valve, 18, cutting off exterior air pressure; and thereupon the vacuum chamber will be re-lled by the liquid lifted by suc'- tion from the low tank, and the previously described operation will be repeated until the liquid rises in the chamber, 2,-and is thereby upheld in the chamber, 3,-to the high level at which the float holds the suction valve closed. And at that condition, the device will cease to operate until the withdrawal of liquid from the chamber, 2, to supply the carbureter, lowers the level in the chamber, 2, and also in the vacuum chamber, 3, to a point at which the suction valve is open as above described.

It will be observed that the vent or relief duct, 20D, must be smaller than the duct, 20a, through which the suction operates for producing partial vacuum in the valve chamber, 21, above the valve, 18, and that the said last mentioned duct is smaller than the duct, 16, through which suction from the vacuum chamber reaches the lower side of said valve, 18, and that the duct, 16a, is necessarily larger than the atmosphere inlet angle-shaped duct, 16". These dimensional relations result first in the production of a limited partial vacuum above the valve, 18,

less than that produced in the vacuum chamber, 5, because of the vent or relief duct, 20h; that when said valve is seated against its upper seat and off' from its lower seat while the suction valve, 24, is open, a limited partial vacuum is produced in the valve chamber, 21, below said valve, 18, less than the partial vacuum produced in the chamber, 3, to the extent that the atmosphere entering through the angle duct, 1Gb, relieves the suction operating through the duct, 16": The result is that the suction operating through the duct, 12a, when the valve, 18, is seated upwardly, closing the vent or relief duct, 20h, is adequate to hold this disk, valve, 18, upon its upper seat against the diminished partial vacuum due to the differences between the two ducts, 16a and 16h, operating at the lower side of said disk valve.

The result of the above described construction, it will be seen is that the atmosphere inlet controlling valve, 18, first seated by gravity on its lower seat, and then held to that seat by the suction from the partial vacuum in the vacuum chamber, 3, while that chamber is iilling with liquid, will not be opened nor make any movement to leave its said lower seat, until the suction valve, 25, becomes seated, cutting off the suction from the chamber, 3, while said suction continues to operate throughthe by-pass duct, 12b, for producing partial vacuum in the valve chamber, 21, above the atmospherecontrolling valve, 18; and that when the suction valve, 25, is thus seated, the atmosphere controlling valve being thus opened by the suction, will be held open, admitting atmosplieric pressure to the vacuum chamber, 3, until the suction valve, 25, is again opened, admitting suction to said chamber, and producing a partial vacuum on the lower side of the atmosphere valve; whereupon immediately said valve will be closed by the superior suction at the lower side added to gravity,-the weight of the valve. Third, that when the engine stops, terminating suction act-ionMthrough both the main and bypass passages-on both valves, the suction valve will drop from its seat and the atmosphere valve will fall to its seat, but will be free to operate as a check valve for admitting atmospheric pressure so that any liquid contained in the vacuum chamber, 3, when the engine stops, will fall at once into the chamber, 2, unless said chamber is already full to the height of the liquid in the vacuum chamber. This last result, while not novel in vacuum fuel feed devices, is of considerable importance for reasons well understood, and it is considered important to point out that the result is not prevented or defeated by the nove-l construction and operation of the valves as above described.

I claim 1. ln a vacuum fuel feed device having a vacuum chamber provided with liquid inlet and outlet; suction connections, and an air inlet, the air inlet comprising a valve chamber having an air inlet port and a port leading to the vacuum chamber; a valve in said valve chamber which seats at both said ports, whereby it cuts ofl' communication between them; a suction duct leading from said valve chamber at the opposite side of said valve from said first mentioned ports, and means for partially offsetting the suction operative through said duct to reduce the partial vacuum in said valve chamber at said opposite side of the valve therein.

2. In the construction defined in claim 1, foregoing, the means for offsetting the suction in said valve chamber being in air inlet port admitting air to said valve chamber at said opposite side of the valve from the two first mentioned ports.

3. In the construction defined in claim 1 foregoing, the means for offsetting the suction in said valve chamber being an air leal; port admitting air to said valve chamber at said opposite side of the valve from the two ports first mentioned, said leali port opening through the valve seat at said opposite side for facilitating the release of the valve from said seat.

t. In a vacuum fuel feed device having a vacuum chamber with a liquid inlet and outlet, a suction connection and an air inlet; a'valve which controls the suction inlet, a float for operating said valve to close it by rise of the liquid level and open it upon the fall of said level in the vacuum chamber; a valve which controls the air inlet positioned for being seated by the suction and also for being opened by the incoming air, and a connection for suction to operate on said valve in the opposite direction from and in less degree than the suction de 1ived from the vacuum chamber.

5. In the construction defined in claimV 4., foregoing, the air inlet comprising two ports opening through the same seat, one leading to the air source and the other-to the vacuum chamber, and a valve which controls the air inlet seating upon said seat to close both said ports at the same time.

6. In the construction defined in claim l, foregoing, the second mentioned suction con* nection being a branch of the first.

7. In a vacuum fuel feeding device having a vacuum chamber provided With liquid inlets and outlets, suction connection and air inlet, a valve for controlling the suction connection positioned for being seated by the suction and opened by gravity; a iioat in the chamber operatively connected with said valve for lifting it to closed position when the float rises; said connection comprising a spring which reacts between the float and the valve for yieldingly transmitting the lifting movement of the fioat to the valve in opposition to the gravity opening action in favor of the suction seating thereof.V

8. In the construction described in claim 4t, foregoing, an air leak at the side of the air inlet valve and which the suction in opposition to that of the vacuum chamber is admitted, the suction controlling valve in the vacuum chamber being positioned for FREDERIK G. WHITTINGTON.

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