US1722037A - Carburetor - Google Patents

Description

yJuly 23, 1929- `J.w.coRsER 1,722,037

CARBURETOR Filed oct. 5, 1925 5 sheets-sheet' 1 j] w A 19 T w y 4 '33 I /20 i 4 kf5 E K2 Il Il /ZZ 32 fik f SAL- 1I E- KJ/0 40" 5 'Tlw' M23 Umm Cof, 4%

July 23, 1929. J, W, CORSER 1,722,037

CARBURETOR Filed oct. 5, 1925 3 sheets-sheet 2 July 23, 1929. J. w. coRsER CARBURETOR Filed Oct. 5, 1925 3 Sheets-Sheet 3 www ne ,SS

Patented July 23, 1929.

r UNITEDy STATES PATENT OFFICE.

CARBURETOR.

Application filed October 5, 1925. Serial No. 60,649.

This invention relates to improvements in carburetors.

An object of the invention is to provide a carburetor having a fuel reservoir in which struction of flow actuated needle valve forl controlling the flow of fuel through the inlet to the carburetor.

A further object of the invention is to provide a carburetor in which there is an air inlet which is normally closed by a pivoted valve, this. valve being so constructed as to assume a normal closed position because of gravity.

Another object of the invention is to provide a carburetor having a mixing chamber and a hollow nozzle which conveys fuel to the mixing chamber and to provide an electric heating element for heating the nozzle, the circuit through the heating element being controlled by a thermostat.

A still further object of the invention is to provide an improved carburetor in which there is a mixing chamber into which the fuel is discharged and in which there is a slidable and reversible member providing a contracted throat.

With the foregoing and other objects in view which will be made manifest in the following detail descriptionand pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein;

Figure 1 is a top plan view of the improved carburetor, parts being broken away and shown in section, which may be considered as taken upon the line 11 of Fig. 2.

Fig. 2 is a vertical section taken upon the line 2-2 of Fig. 1.

Fig. 3 is a horizontal section taken upon the line 3-3 of Fig. 2.

Fig. 4 is an end elevation of the carburetor taken in the direction of the arrow 4 upon Fig. 2.

Fig. 5 is a vertical section taken upon the line 5-5 of Fig. 2.

Fig. 6 is a horizontal section taken substantially upon the line 6-6 of Fig. 2.

Fig. 7 is a side elevation of the hollow no'zzle and the cap thereon, providing a jet formlng means4 for the carburetor.

Fig. 8 is a perspective view of the removable receptacle which is positioned within the fuel reservoir. l

Referring to the accompanying drawings, wherein similar reference characters designate similar parts throughout, the improved carburetor consists of a body 10 preferabl formed of a single integral casting, althougii 1t may be built up of separate parts. In this body there are formed what will hereinafter be termed as a fuel reservoir 11, an air inlet 12 and a mixing chamber 13. On top of the fuel i reservoir 1l there is detachably secured a cover 14 which is held in place by means of screws 15 passing through lugs 16. A threaded nipple 17 is screwed into the cover and forms the inlet to the fuel reservoir. This nipple is secured in place by means of a lock nut 18 and is adapted to have a fuel conduit connected to it. On the lower end of the 4nipple 17 there is provided a sleeve 19 which serves as a guide for a needle valve 20 adapted to seat upon the lower end ofthe nipple 17. A receptacle 21 has an outwardly extending flange 22 formed von its upper end and is se cured upon the cover 14. This receptacle has a screen or reticulated bottom` wall 23 and can be removed from the fuel reservoir 11 upon removal of the cover 14. The lower end of the needle valve 20 is provided with a head 24 which engages upon a ioat 25 preferably consisting of a hollow ball which is disposed within the receptacle 21. In this manner the needle valve 20 rests upon and is supported by the float 25 and upon the fall of liquid within the fuel reservoir 11 the lioat will permit the needle valve 20 to become unseated.

95 As the needle yvalve fits loosely within the sleeve 19 or there may be grooves formed upon the interior surface of the sleeve, fluid may readily enter the fuel reservoir through the nipple 17 and in this manner the fluid 100 level will be practically kept constant. As 'all of the yfuel must pass through the screen 23, it will be readily appreciated that impurities will'be retained within the receptacle.

The screen preferably is a very fine screen 105l which is capable of even straining out water which may be in the fuel, it being understood that the surface tension of the globules of water in the fuel is such that it will not permit them to pass through the fine screen under 110 lco most circumstances. The outlet from the fuel reservoir is formed by means of passages or bores 26 and 27.

A hollow nozzle 28 is threaded into the body 10 and extends upwardly into the mixing chamber 13. This nozzle has its lower end closed and is secured in position by means of a lock nut 29. Apertures 30 are formed in the nozzle permitting fuel to enter it from the bore 27. On the top of the nozzle 28 there is threadedly mounted a cap 31 preferably presenting an appearance of the frustrums of two cones arranged base to base.V In the cap 31 there is formed a plurality of radial bores 32 which are arranged in the same plane and are directed toward the walls of the mixing chamber 13. Immediately below the inner ends of the bores 32 there is provided a valve seat for a needle valve 33 and controls the flow of fuel through 'the hollow stem 28 and through the bore. This needle valve 33 is slidableupon the cap and is'normally urged into elevated or open position by means of a coil spring 34 compressed between the cap 31 and the head on the needle valve.

A rock shaft 35, which is pivotally mounted upon a pipe section or coupling member 36, carries a cam 37 engageable upon the head of the valve 33 so as to adjust the valve with respect to its seat. Thek pipe section or coupling member 36 is detachably fastened to the body 10 by means of screws 60 and lu s 61 and upon its upper end there is provi ed a flange 62 by which it may be 'connectedto the conventional intake manifold upon an internal combustion engine. The rock shaft 36 maybe turned by means of `a crank 38 and maintained in adjusted position by means of a set screw 39.

The air inlet 12, which communicates with the mixing chamber 13 at its bottom, is pref-f erably rectangular in form and has a valve 40 pivotally mounted therein upon pintles 41. The pintles 41 are arranged above the center of gravity of the Valve 4() but below its upper edge so that the valve will normally swing into the position shown in Fig. 2 under the force of gravity. However, when there is a draft through the inlet 12, the lower end of the valve may swing inwardly, and the upper end of the valve will swing outwardly so that air enters the air inlet 12 both above and belo'w the pintles 41. Consequently, there will never be a partial vacuum of any great magnitude formed immediately behind the valve, and the pressure of the draft both above and below the pintles will somewhat tend to counterbalance. This construction provides for a type of automatic air adjustment permitting the air to flow through the inlet but retarding its movement.

Upon the interior surface of the mixing chamber 13 there is formed an annular shoulder 42 and on the couplin member 36 there is formed an interior annu r flange 43. The

s the rise in temperature.

lwardly therethrough and is ridge 45 provides a contracted throat upon the member 44 or a type of venturi. A

The conventional butterfly or throttle valve is indicated at 46 and is mounted upon the coupling member or pipe section 36. About the nozzle 28, below the ca 31, there is disposed an electric heating e ement 47, preferably enclosed within a sheath or guard 48 whlch may have insulating material upon its interior surface. A recess 49 is formed in the body 10 about the bottom of the hollow nozzle 28. This recess is covered by means of a suitable closure 50 and has a screw'51 extending into it from the outside of the body 10. The inner end of thel screw 51 is provided with a contact which is engageable by a contact 52 on an arcuatelmember 53 mounted upon the bottom of the sheath 48 within or beneath the closure 50. This arcuate member is formed of two layers of different metals secured to gether, which metals have different coeiicients of expansion under the effect ofk heat. The metals which form the arcuate member 53, which will hereinafter be termed a bi-metallic member, are soarranged that ".1, u on rise in tem erature the diameteracross t e arcuate mem er will tend to decreseand .L ;k upon the fall of temperature the diameters..A

across the member will increase. In this manner the bi-metallic member 53 serves as a thermostat, causing the contacts to engage upon the fall of temperature and to disengage upon v The y bi-metallic member carrying the contact 52 may be connected through theheating element 4 to a source of electric current such a's a stora e battery as indicated at 54, so that when t l e contacts engage, the electric element 47 may grounded if desired, and the screw 51 ma be be energized and when the contacts are sepas rated the electric circuit through the heating element will be broken.

The operation of the carburetor is as follows The fuel entering the nozzle 28 through the bores 27 from the fuel reservoir dpasses up# ischarged through the bores 32, where it is mixed with the air enterin through the air inlet 12 past the valve 40. en the member 44 is resting upon the shoulder 42, it tends to form a coni stricted annular passage between its ridge 45 and the cap 31 increasing the velocity of the air as it passes through the passage. This velocity of air tends to draw the fuel out of the bores 32, it bein readilyappreciated that the hydrostaticleve in the fuel reservoir and in the hollow stem 28 ispreferably just below the bores 32. Obviously the higher the veloc-v ity of the air, the greater amount of fuel will be drawn through the bores 32 and the greater the distances between the member 44 and the cap 31, the lower the velocity will be and consequently a smaller amount of fuel will be withdrawn. The amount of fuel withdrawn determines whether it will be a rich or lean mixture.

In the idling position the member 44 rests upon the shoulder 42. However, when the throttle valve 46 is opened materially, the increased draftof air will lift the member 44 and cause it to engage the flange 43, thus making the mixture developed somewhat leaner at higher speeds. When the throttle valve is partially shut oil", however, the member 44 falls under gravity and increases or enriches the mixture. The quality of the mixture may be varied both in idling and in speed conditions by rotating the rock shaft 35, thus adjusting the needle valve 33.

If it is desired to change the quality of mixture at idlingposition, the coupling 36 may be detached and the member 44 caused to assume a reversed position. As the ridge 45 is unequidistant from the top and bottom edges of the member 44, such a reversal will cause the ridge to assume a different position with respect-to the cap 31, when the member 44 is resting on the shoulder 42. By virtue ofthe fact that the cap 31 is threadedly mounted upon the nozzle 28, it can be adjusted toward or away from the slidable member 44 when in its lower position. This adjustment varies the quality of the mixture. If desired, the quality of mixture and quantity can be varied greatly by removing the cap 31 and the member 34 and replacing these arts by a cap and member of different size. uch removal and replacement is permissible by virtue of the fact that the cap is'threaded onto the nozzle 48, and that the slidable member 44 can be withdrawn through the top of the mixing chamber. l

By this construction it will also be appreciated that when the throttle valve 46 is in open position that the throat will be remote from the point where the fuel and air are initially mixed. By running the fuel and air together through a contracted throat, an eiiicient mixture is produced and when the throat is remote from the initial point of mixing in high speed conditions the air and fuel are lirst mixed and then run through the throat, and will practically assure a proper and thorough mixture of fuel and air.

The purpose of the heating element 47 is to heat the fuel passing through the nozzle 28 before it enters the mixing chamber. '.l'he heating element is preferably so designed that it can quickly raise the temperature of the fuel to substantially its boiling point, so

that when the fuel enters the mixing chamber, it will be heated and can be easily vaporized. By this construction it will be appreciated that it will be practically impossible to have any raw or unvaporized fuel enter a cylinder of the internal combustion engine which might dilute the lubricating oil in the crank case. As the sheath 48 is apt to become heated by the heating element, the heating element also warms up the air entering the inlet 12 before it enters the mixing chamber. It will be readily understood that the thermostat may be employed to control the heating element or the heating element may ne controlled by a hand operated switch, if found desirable.

The operation of the thermostat for controlling the operation of the heating element is believed to be readily apparent. Upon starting up an engine to which the carburetor is applied, the heating element 47 may be energized, but when the engine becomes warm to warm the carburetor and the air entering it, the contacts will be separated and the heating element will no longer be operated.

From the above described construction it will be readily apparent that an improved form of carburetor is provided, having many advantageous features vover the carburetors heretofore produced. In actual practice tne carburetor of the improved construction has been found to be very eiiicient and economical upon fuel.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

What I claim is l. A carburetor having a vertical mixing chamber of substantially uniform internal diameter, a throttle? valve for opening and closing the upper end of the mixing chamber, a nozzle having a plurality of outwardly directed bores for conveying fuel into the mixing chamber, an open ended member slidable in said mixing chamber and having a smaller internal diameter intermediate its ends than at its ends, means for limiting the upward movement of said open en'ded member, and means limiting the downward movement of said open ended member so that its minimum internal diameter will be adjacent but slightly spaced from the ends of the bores on the nozzle, thus dening a relatively narrow passage through which air may flow across the ends of the bores when the throttle valve approaches its closed position, said open ende'd member being capable of sliding in said mixing chamber to its uppermost position so as to increase the size of the air passage over the ends of the bores as and for the purpose described, the point of minimum diameter in said open ended member being more adjacent one end than another, so that upon reversing it in the mixing chamber'the size of the air passage when the open ended member is in its lowermost osition will be varied.

2.` In a car uretor, means including two superimposed parts providing a mixing chamber, a nozzle for supplying fuel to the normally assuming a position spaced from mixing chamber mounted upon the lower the nozzle but When the draft through the part, a needle valve carried by the nozzle for mixing chamber is increased, is adapted to controlling the flow therethrough, spring rise Within the mixing chamber about the -5 means urging the needle valve into open poneedle valve to a position remote'from the 15 sition, a rock shaft rotatably mounted upon nozzle. the upper part, acam carriedbytherockshaft In testimony whereof I have signed my engageable upon the needle valve to move it name to this specification.

- into closed position, and means providing a 10 oating venturi within` the mixing chamber, JOHN W. CORSER.

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