US1806790A - Gaseous fuel mixing device - Google Patents

Description

VE DE May 26, 1931. P. J. DAsEY A GASEOUS FUEL MIXING DEVICE Filed sept'. 22, 1927 EEEMW Il |H ////ll//////llll/ Para# asey by M Patented May 26, 193i i* UNITED STATES PATENT OFFICE PERCY J. DASEY, F CHICAGO, ILLINOIS GASEOUS FUEL MIXING DEVICE Application led September 21.2, 19g?. Serial No. 221,170.

pressure and the variation of sub-atmos' pheric pressure of air at the manifoldintake,j

which latter effect may be due to variation of speed of the engine.

Another object of the invention is to provide a device of the character herein disclosed which may be alternatively used in conjunc- 20 tion with the standard carburetor by which gasoline vapor, primarily `at approximately atmospheric pressure, is mixed with air under sub-atmospheric pressure effected by the inspiration stroke of an engine. A further object of the invention is to provide a mixer in which the undue variation of v fuel supply caused by the variation of engine speed is overcome by the same effect whereby the approximately correct amounts of gas '30 and air are admixed and the consumption of said mixture is rendered substantially proportional to engine load. In other words, the increase of throttle opening to increase engine speed in the ordinary engine would bring .about a heavy flow of mixture, air and gas into the cylinders, the tendency being, as speed went up, to reduce the amount of gas per cylinder charge of air and inversely, as engine was throttled down,l the gas flow would tend to enrich the mixture, thus reducing eiiciency-,power output and economy. This is overcome by operation of means responsive to such variation to maintain the fuel volume at the desired value regardless of variation of engine speed.

A further object ofthe invention is to provide means for approximately offsetting or counterbalancing the pressure of the incoming gas so that at all engine speeds and under 50 varying load conditions, thegas supply is dependent upon vacuum conditions within the mixer and practically independent of the pressure of the gas lineahead of the counterbalancing means, otherwise at low engine speed, the gas being under pressure, would 'cause the mixture to become too rich for the proper operation of the engine.

Other objects, advantages `and benefits of the invention Will readily appear to persons skilled inthe art from a consideration of the v following description, claims and accompanying drawings forming a part hereof wherein:

Figure 1 isa plan View of `an embodiment I of a device disclosing my invention.

Figure 2 is a section taken on lines II-II of Figure l.

Figure 3 is a modification of a part of the device shown in Figure 2.

In all of the views 'thesame reference characters indicate similar parts. 3

`When ordinary mixing valves are used with internal combustion engines, with which a gas under pressure is employed as fuel, the needle valve may be set so that the engine will operate very satisfactorily atl constant speed and with constant load, but when these factors vary, the quantity or volume of fuel must be automatically varied to maintain satisfactory goperation. Gas, under pressure, cannot be used with the standard gasoline carburetor through which the mixture is drawn by suction, or attenuation of air, Within the intake manifold, because air is forced through, or caused to flow through the carburetor by atmospheric pressure and the sub-pressure present in the chamber into which the air is flowing.

If gas under pressure is allowed free ingress into the mixing chamber of the carbu-A retor, the fall of pressure within the mixing chamber cannot ,be largely ee'cted by the suction of the engine. Consequently, the ingoing charge will be substantially all gas unmixed with a suitable volume of air and therefore the charges will be toolrich to be exploded in the combustion chamber of the engine. 4

To overcome thisdiiiiculty and to render the engine operative alternatively with gas j by the gas under normal pressure but which will be opened automatically when the outer surrounding air in the gas chamber is below atmospheric pressure, as`may be produced by the suction of theengine or by the vacuum tendency which prevails within the intake manifold of the engine. As this vacuum tendency at the gas carbureter valves, the effect of which is used .to draw gas and air into the engine, is decreased as the speed of the engine is decreased, gas being under pressure would flow into the carbureter in larger proportionate volume than would the air under atmospheric pressure and thus the mixture would become too rich at low speeds for proper propagation of flame and the eliiciency would thereby be greatly decreased;

The valves 8 and 11 working in unison are to proportion gas and air only after said gas and air reach the valves under proper conditions of pressure. Without the floating valve, to reduce gas to atmosphere and subject to vacuum demand only, valves 8 and 11 operated with or withoutmanifold vacuum bellows control could only ratio gas under pressure and air at atmosphere, at one set speed and load. If engine is speeded up then gas would gradually thin out to a lighter mixture and if engine speed was reduced to idling, gas under pressure would naturally flow 1n larger volume than was required at that speed, and the mixture would become too rich, hence the necessity for the floating valve in order to put both, gas and air on same basis-virtually at atmospheric pressure. g

Referring to the drawings by which an embodiment of my invention is exemplified, 5. is a casing containing a mixing chamber 6, an inlet conduit for air, 7, and an outlet 9 for the combustible mixture.

A relatively large valve 8 yieldingly and normally closes the mixing chamber 6. The

\ valve 8 is mounted on and secured to a vertically slidingstem 10. A gas valve 11 has an internally threaded sleeve prolongation 12 vertically adjustable by its rotation on the stem 10 and held in adjusted position by the check nut l3'which is threaded to the upper end of the stem 10. A spring 14 having one of its ends seated upon the upper end of. the valve 11 and the other end under the adjustable nut 15 yieldingly holds valves 8 and 1'1 closed. The plan area of valve 8 is very much greaterthan that of valve l1 as shown.

The nut 15 may be moved downwardly by its rotation and thus increase the tension of the spring 14 and it Vmay be rotated in the opposite direction and thus decrease the tension of the spring 14. A spring nger 16 holds the nut in adjusted position.

The knurled disk 17 is part of the sleeve 12 and serves as a convenient means for rotating the valve 11 and sleeve 12 on the stem 10. An arm 18 is provided withy a series of holes 19.y An arm 20 pivotally supports a lever 21 and when it is desirable to hold both valves 8 and 11 open, the outer end of the 1ever21 is depressed and a pin 22 is inserted in a hole 19 just above the outer end of the lever 21 for a purpose to be hereinafter more fully explained.

A gas chamber 23 communicates with the mixing chamber through the port of gas valve 11 when the latter is open. A conduit 24 projects from the gas chamber 23 and is connected to a conduit 25 which is part of the casing 26. The threaded end 27 of the casing 26 is for connection with a pipe or conduit (not shown) to a source of gas supply which supply may` be under pressure of several ounces above atmospheric pressure. 1

A valve 28 is essentially like valve 11, and closes communication between the-gas supply and the gas chamber 23. A spring 29 has its lower end resting on top of valve 28 and its'upper end resting under the vertically adjustable nut 30. A valve stem 31 is guided in the nut 30, a spring finger 32 holds the nut 30 in adjusted position. The tension of the spring 29 is adjusted by the nut 30, so

lili` that the pressure of the gas of the gas supply will not be suiiicient to raise the valve 28 againstthe pressure orv tension of the spring 29. The weight of valve 28-may be varied in whih event the spring 29 may be dispensed wit Y It is of course manifest that if valve 28 re! main open, gas would flood the mixing chamber 6 because of its pressure and the suction of the -engine would not be sufficient to raise the air valve 8 sufficiently to admit the proper amount of air to produce an explosive mixture. The absence of air would make the mixtureso rich that it probably would not ignite and if it did ignite, the propagation of flame would be so slow that efficient results would not be accomplished.

The floating valve 28 overcomes this objection mentioned. As an alternative means of controlling the operation of valves Sand 11, other than by spring as shown, I provide a contractivble bellows diaphragm 33 and secure its upper end to the lower end of the stem 10` and its lower end to the casing 5.

The interior. of the diaphragm 33 is connected to the intake manifold of the engine by tube 34. As the vacuum tendency is increased under partially closed throttle and decreased under wide open throttle, the dia- `gas 'going into the cylinders of the engine.

The normal condition of the bellows is fully expanded and the controlling movement is brought about by the variation of vacuum conditions in the manifold.

When the device 33 is used in the manner described, it is necessary to relax the adjusting spring 14; or to entirely remove it.l

As the vacuum tendency is increased and by which valves 8 and 11 would be opened wider, the same tendency will cause the device 33 to impose correspondingly more resistance to the opening movement of valves 8 and 11, and therefore the character of the n vfuel charges will be appropriate to speed variations of the engine.

When the device describedis to be used with fuel gas and independently of a gasoline carburetor, the throttle 35, shown in dotted. lines, should be used as a speed control. When the device is to be connected tandem with a gasoline carburetor and engine operated on gasoline as fuel, the Vthrottle 35 may bev entirely dispensed with or fixed in open position. Under such conditions, valves 8 and v11 should be maintained in open' positions.

This may be done by depressing the outer end of lever 21- and putting the pin 22 in the hole 19 immediately above the lever.

The device, as described, may be independently connected to an internal combustion engine and a gasoline carburetor may also be so connected and by use of a suitable three-way valve, either device may selectively be used.

I am aware thatmany changes may be made, and numerous details of construction may be varied through a wide range without departing from the principles of this i invention, and I therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

I lclaim as my invention:

1. In combination, a gaseous fuel mixing device having a casing for connection 'to the intake manifold of an internal combustion engine, the casing having a mixing chamber, meansl forming a gas chamber communicating with the said mixing chamber, anl air valve in the casing, a gas valve controlling the communication between the gas chamber and the mixing chamber, means connecting the gas valve and the air valve for conjoint operation,

, the aforesaid valves being normally closed and being arranged to be opened by areduction of pressure on one side of the air valve, a gas conduit for the gas chamber adapted to be connectedto a gas supply system, and

- adjustable valve means normally closing the conduit arranged to open only when the first mentioned gas and air valvesv are open, the said latter valve means beingadjusted to be balanced against the pressure of the gas sup-- ply system."

2. In combination, a gaseous fuel mixing device having a casing with an outlet conduit for connection to the intake manifold of an internal combustion engine, an air valve and a gas valve in the casing connected for .conjoint operation, the said valves being arranged to be normally closed and to open by a reduction of pressure in the casing, and suction operated means connected to the air -valve to oppose .the opening of the valve, the

said suction operated means having a conduit for connection to the intake manifold conduit connection. Y

3. In combination, a gaseous fuel mixing device having a casing with an outlet conduit for connection to the intake manifold of an internal l'combustion engine, an air valve and a gas valve in the casing connected for conjoint operation, the said valves being arranged to be normally closed and to open by a reduction of pressure lin the casing, and suction operated means connected to the air valve to oppose the opening of the valve, the said suction operated means including an expansible bellows having a conduit for connection to the intake manifold outlet conduit connection.

lhaving an integrally formed air Iintake conduit with a valve seat therein, an integrally formed fuel outlet conduit, and a threaded gas intake in alinement with the air intake, a second casing forming a gas chamber and having an extending gas intake conduit and a gas outletthe said second casing being mounted in threaded engagement with the first casing in its gas intake to define a mixing chamber for the carburetor, a valve on the seat in the air intake, a valve in the second casing to control its gas outlet, a spindle extending through both of the casings and guidedly connecting the said valves, means mounted on the second casing for controlling the operation of the said valves, the said valves being arranged normally closing the air intake and the gas outlet, and to be opened by a reduction of pressure in the mixing chamber. j

In testimony whereof I havehereunto subscribed my name at Chicago, Cook County,

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