US1209747A - Carbureter. - Google Patents

Description

I. w. IvIo'wBRAY.

CAHBURETER.

APPLICATION FILED Nov. 9, I9I4. IIEIIEWED sEPLa, 1916.

Patented Dec. 26, 1916.

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INI/ENTOR.

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A TTORN E Y.

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JAMES W. MOWBRAY, OF WINDSOR, ONTARIO, CANYADA, ASSIGNOR, BY

MENTS, TO GEORGE L. BROWN, OF PORT HURON, MICHIGAN.

MESNE ASSIGN- QBURETER.

Lenmar.

To all wlw/m, t may concern:

Be it known that I, JAMES W. MowBRAY, a subject of the King of Great Britain, residing at Windsor, Province of Ontario, Dominion of Canada, have invented -a certain new and useful Improvement in Carbureters, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to carbureters and its object is a simple, inexpensive and efficient device for use in vaporization of hydro-carbon fuel for internal combustion engines.

A further object is a carbureter in which the fuel supply is directly proportional to the quantity of air passing therethrough, at all speeds of operation of the attached cngine, in combination with tinct atomizations of the fuel as it passes through the carburetor to the engine resulting in a standard carburation with more resultant power, less carbon deposits, and ease in starting.

An additional object resides in the means employed in relieving the fuel charge of excess pressure under high engine speed.

I am aware of other carbureters providing a fuel charge supplied from two sources, one

"o-fl which is constant per unit of time, and

one of which is variable per unit lof time. This invention, therefore, relatest-more particularly to means, in combination with such compensating fuel supply, to more effec-` tually break up or atomize the fuel and effect a higher degree of vaporization, whereby the mixture is more readily explosive and more completely burned in the cylinders.

These and other objects and various other novel features of construction by which they may be attained are hereinafter more fully described and claimed and shown in the accompanying drawing in which- Figure l is a plan view of a carbureter embodying my invention. Fig. 2 is a ver# tical vsection of the Venturi tube taken on line -:r of Fig. 1. Fig. 3 is a vertical section of the fuel chamber taken on line g/-y of Fig. 1. Fig. 4 is a vertical section taken substantially on line z-e of'Fig. 1. Fig. 5 is a plan view zontal plane through the fuel. conduit.

Specification of Letters Patent.

a plurality of dis-A partly in section on a hori- Similar characters refer to similar parts throughout the drawing and specication.

he carbureter consists of an air tube 1 having the shape of a Venturi tube provided with a throttle valve 2 of ordinary type and a shutter valve 3 near the intake end of the tube. The valve 2 is provided with a control lever 4 and the valve 3 is provided with a control lever 5 both of which may be operated from a remote point if desired. The stem 6 of the valve 3 is also provided with a coiled spring 7 tending to hold the valve full open at all times so that, upon release of the lever 5 after the valve has been partially closed, the valve is immediately returned to normal open position through operation of the spring 7 `Formed integrally with the air conduit 1 is a fuel chamber 8 having an inlet 9 at the bottom thereof, controlled by a needle valve 10, which is actuated through movement of a float 11 tending to maintain a constant fuel level in the fuel chamber in the manner well lnown with such devices. The chamber 8 is provided with an aperturedcover 12 held in position byA a screw threaded pivot 13.

Formed in an enlarged part of the fuel chamber wall are two Wells 14 and 15 having - passageways 16 and 17 respectivelyleading into the fuel chamber below the fuel level therein as shown more particularly in Fig. 4. The fuel well 14 is provided with an air tube 18 extending downward thereinto preferably close to the bottom of the welll and the upper end of the well is closed .to atmosphere exvcept through the interior of the tube. The 7tube is made smaller in diameter than the well thus allowing the fuel to rise about the exterior of the tube within the well.

The well l5 terminates at the upper end in a seat 19 for aneedle valve 20 by means of which the flow of fuelfrom the said well may be regulated. rIhe body of the valve is threaded and provided with a head 21 by vmeans of which it may be turned and a coiled springl 22 is also provided engaging against said head and the carbureter body with sufficient force to prevent accidental `turning of the needle valve. Communicating with the upper end of both these wells is a passageway 2,3 leading to a channel 24 formedbetween two constituent parts of a secondary air conduit 25. The channel 24 is preferably V shaped being formed by the adjacent cone-shaped ends of the two parts Patented-Dec.. 26, 1916. Application nl ed November 9, 1914, Serial No. 870,963. Renewed September 8, 1916. Serial the throttle is gradually. opened of the air conduit, the upper part of which is supported by the shoulder 26, and the lower part of which is supported in position by the shoulder 27. Both said parts tightly fit in apertures in the wall of the air conduit 1 and are pressedinto place. The lower end of the secondary conduit 4passes into the main air conduit 1 at the point of greatest restriction terminating near the center thereof so that the fuel channel 24 is subject to the influence of air passing through the conduit 1. The two parts of the secondary air conduit are not.quite in contact leaving a space of about one sixtyfourth of an inch between the two sharp edges of said parts' and thus air passing through the secondary air conduit draws the fuel from the channel 24 across and between these sharp edges which eectually breaks up the globules of the fuel and aids in the atomization thereof. v

An air passage 28 is provided in the passageway" 23 between the two points at which the fuel from the wells enters the passageway. This air passage 28 leads into the fuel chamber above the fuel" level therein whereby air is drawn into the said passageway 23 tending to primarily atomize the fuel from the said wells. In passing through the tube 23 andthe conduit 24 into the secondary air passage 25, a second mixture of air with the fuel charge takes place so that the fuel is in quite finely divided state at the time it enters the main Venturi tube where the final atomization of the fuel is completed by reason of the air passingkthrough the said tube 1 and cross the lower end of the secondary conuit.

A passageway 30 is formed-inthe wall of the Venturi tube leading into the interior Vof the tube at a point adjacent the edge of the throttle valve 2, when closed or nearly so,

' as is indicated in Fig. 5. The tube 31 procommunication between vides a means of the fuel channel 24 surrounding the secondary air tube and` the conduit 30. With the throttle nearly closed (at the time of starting the engine for instance) only a small volume of air passes through the main air conduit 1 and, therefore an insuicient degree of vacuum is produced at the mouth of the secondary air conduit to draw fuel through saidconduit but the rush of air past the edge of the throttle valve2 is sufficient to draw the fuel through the tube 31 and passageway 30 into the air tube 1. As the degree of vacuum at the mouth of the secondary air tube is increased and that at the mouth of the passageway 30 is decreased until practically the entire fuel charge enters the main conduit through the' secondary air conduit 25.

It is to be noted that the passageway 16 at the lower end of the well 14 is small in size Lacan? restricting proportion plying the flow .to the said well while the aperture 17 in the bottom of the well 15 is practically ofthe diameter of the well so that the iow thereto is practically unrestrictefi and both said wells are subject to atmospheri@ pressure. The constant fuel supply well14, as before stated, is provided with an air tube 18 terminating near the bottom of the well and the function of this air tube is as follows :--When the engine to which the carbureter is attached is idle, the fuel -in the well 14 rises to the level of the fuel in the fuel chamber both inside and outside of the air tube 18. With the throttle tightly closed, if it be possible for the engine to be operated'under such condition, a high degree of vacuum would be produced on the engine side of' the throttle, while no degree of vacuum on the carbureter side Aof the throttle would'be produced. If the throttle is partially open fuel is drawn into the main air conduit eitherthrough the secondary air conduit or the passageway 30, or' both, and from both wells as heretofore described. As the suction on the oil wells increases by further opening of the throttle, the level of fluid in the air tube 18 gradually descends while the fluid outside of the said tube passes into the Vfuel conduit 23. The

f crease in the fuel supply under constant increase in vacuum. With an ordinary carbureter unprovidedwith such compensating device, the fuel supply, from the time the throttle valve is about one half open until it is fully open, is too great in proportion to the volume of air, but, by partially relieving the oil from the influence of the vacuum produced in the tube after a certain degree of vacuum has been attained, the fuel supply is maintained 4in practically constant to the air passing through the conduit. 4

It is also to be noted that the sizes of the various conduits and apertures vary with the size of the carbureter and engines supplied thereby. In a one-inch carbureter supand one-half inch or three inch bore and four inch stroke, 1 have' found that the passageway-16 should be made with a No. 60 drill. The paa eway 17 should be formed with a No. 42 dril and the two parts of the secondary air tube 25 should be setabout one sixtyl fourth of an inch apart. The primary air passage 28 should be formed with a No. 56

a four cylinder motor of about two 1-2 and the passageway 25 through the 13 wells 14 and 15, through the fuelchannel r1 In starting of the engine, the throttle is Y very nearly closed which, as before stated,

causes a rush of air past the mouth of the passageway 30, drawing fuel from both the 24 surrounding the secondary air tube. When the throttle is opened farther and the engine speeded up the greater volume of air drawn ,through the tube 1 causes a greater degree of vacuum at the mouth of the secondary air conduit and draws fuel from the channel 24 into the main air conduit lsubstantially at the point of greatest restriction, and some fuel also will flow into the air conduit through the passage 30. When the throttle is fully opened the suction at the mouth of the tube 30 is reduced to a minimum, while that at the mouth of the seconda-ry air tube is increased to a maximum, and little or no fuel enters the main conduit through the passage 30.

The flow of the fuel to the well 14 through the restricted passageway 16 is substantially con-stant. Consequently, as the engine speed is increased, the proportion of fuel from the said well to the volume of air passing through the carbureter decreases, thus providing a source of supply that is constantly poorer as the engine speed increases. The flow to the well 15 is variable per unit of time, that is, increases as the engine speed increases, in such manner that the supply from the said well is constantly increasing in richness in proportion to the air passing through the main conduit. By utilizing both sources of fuel supply, a fuel charge is provided that is constantly in proportion to the volume of air passing through the main conduit. This feature, however, is well known in the art. By introducing an air passage 28 in the fuel conduit 23 substantially as shown, the fuel is partially atomized as it passes into the conduit from the wells. By adding further air to the A charge and breaking up the globules as they pass through the channel 24 into the secondary air-passa e 25, a second atomization of the fuel takes place so that, at the time the fuel enters the main air conduit, it is in a finely divided-state and, in passing into the main air conduit, is in condition to be thoroughly mixed with the air therethrough at which point the fuel is completely atomized. I, therefore,` do not claim broadly the compensating fuel wells, but

What I do claim and desire to secure by Letters Patent of the United States is 1. In a carbureter, an air conduit, a fuel conduit 4subject to the influence of air passing through the air conduit, a suction controlled fuel feed, a fuel feed giving a constant supply per unit of time, both said feeds being in communication with the fuel conpassing duit, and a restricted duit, and a restricted' air passage leading into the fuel conduit adjacent the points of communication of the fuel feeds therewith. 2. In a carbureter, an air conduit, a secondary air conduit leading thereinto, a fuel conduit discharging into said secondary conduit, a fuel feed variable per unit of time and a fuel feed constant per unit of time both discharging into the fuel conduit, and an air passage leading into the fuel conduit in proximity to the points of communication of the fuel feeds therewith.

3'. In a carbureter, an air conduit having the form of a Venturi tube, a secondary air conduit leading thereinto substantially at the point of greatest restriction, a fuel conduit discharging into the secondary conduit, a fuel supply variable per unit of time and a fuel supply constant per unit of time both communicating with the fuel conduit, and a restricted air passage leading into the fuel conduit in proximity to the points of communication'of the fuel supplies therewith.

In a carbureter, an air conduit having the formof a Venturi tube, a secondary air conduit leading thereinto substantially at the point of greatest restriction, said secondary conduit being of two parts spaced a slight distance apart and so formed as to provide a fuel channel about the said conduit communicating with the air conduit thf'ough the interstice between the said parts, a fuel conduit communicating with the said channel, a fuel supply variable per unit of time and a fuel supply constant per unit of time, both communicating with the fuel conduit at separate points, and a restricted air passage leading into the fuel conduit between the points of communica.- tion of the fuel suppliestherewith.

5. In a carbureter, an air conduit having the form of a Venturi tube, a secondary air conduit leading thereinto substantially at the point of greatest restriction therein, said secondary conduit being formed of two parts having cone-shaped ends providing sharp edges about the conduit opening and spaced a short distance apart forming a channel in communication with the secondary conduit, a fuel conduit communicating with said channel, a fuel supply variable per unit of time and a fuel supply constant per unit of time,both communicating with the fuel conair passage leading into the fuel conduit in proximity to the points of communication of the fuel supplies therewith.

6. In a carbureter, a throttle controlled air conduit having the form of a Venturi tube, a secondary air conduit discharging thereinto substantially at the point of greatest restriction, the secondary air-conduit being formed of two. portions set a slight distance apart and so formed on the adjacent ends as to provideI a fuel channel communicating with the air conduit lthrough the interstice between the said parts, a fuel supply variable per unit of time, a fuel supplyconstant per unit of time both in communicavtion with the channel,an air passage leading per unit of time also in communlcation withx the fuel chamber below the fuel level, a fuel conduit subject to the influence of air passing into the secondary conduit, an air passage leading into the fuel-conduit in proximity to the points of communication of the fuel supplies therewith, said air passage leading into the fuel chamber above the fuel level therein, and a throttle valve for con.- trolling the flow of air through the main air. conduit. t.

v 8. In a carbureter, a main air conduit having the form of a Venturi tube, a secondary air conduit leading into the main conduit at the point of greatest restriction, the secondary conduit being formed of two parts having separated adjacent ends, a fuel channel formed4 about the secondary conduit and communicating therewith through the interstice between said ends, a fuel conduit leading into said channel, a fuel supply constantper unit of time, and a fuel supply varian into the fuel conduit, a constant level fuel chamber, a fuel passage for each of the fuel supplies communicating with the fuel chamber below the normal fuel level therein, an

air,passagefcommunicating with the fuel conduit in proximity to the points of communication of the fuel supplies therewith, said passage leading into the fuel chamber above the normal fuel level therein, and a throttle valve lcontrolling the main air conduit..

9. In a carbureter, an air conduit, a fuel conduit sub]ect to the inliuence of air passing through the air conduit, a fuel well having a restricted fuel` inlet at the bottom adapted to provide a constant supply per unit of time, a fuel' well having an inlet at c per unit of time both discharging` lvariable per unit of time, both said wells opening into the fuel conduit, and an air tube extending into the well of constant supply and terminating near the inlet providing the sole means for supplying air to said well.

10. In a carbureter, a main air conduit, a secondary air conduit leading thereinto, a fuel conduit discharging into the secondary air conduit, a constant level fuel chamber, a fuel well adapted to provide a supply constant per unit of time, a second fuel well adapted to provide a supply variable per unit of time, both said wells discharging into the"l fuel conduit and being in communication. with the fuel chamber at the bottom, an air tube extending into the constant supply well and terminating below the' normal fuel` level therein providing the sole means of admitting air into the well, an air passage leading into the fuel conduit in proxlimity to the points of communication of the 11. In a carbureter, a main air conduit v having the form of a Venturi tube, a secondary air conduit leading thereinto at the points of greatest restriction, "said Secondary air conduit being formed of two spaced parts formed to provide a circumferential fuel 4channel dischargingfinto the conduit through the interstices between'the parts, a fuel conduit discharging into the said channel, a vconstant level fuel chamber, a fuel well adapted to provide a supply constant per unit of time, a second fuel well adapted to provide a supply variable per unit of time, both said wells discharging into the fuel conduit and being -in communication with the fuel chamber at the b'o'ttom, the air tube extending into the constant supply well and terminating below the normal fuel level therein providing the sole source of air supply for said well wher'i'the fuel in the tube has been drawn out by reason of the vacuum produced in the main air conduit and thereby relieving the fuel conduit of excessv pressure due to said vacuum.

In testimony whereof, I sign this specification in the presence of two witnesses.

JAMES w. MowBRaY.

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