US 2016449 A
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o. MoYsARD Oct. 8, 1935.
CARBURETOR Filed Sept. 19, 1935 OMER MOVSARD INVENTOR i BMp/@g ATTORNEYS Patented Oct. 8, 1935 UNITED STATES PATENT OFFICE CARBURETOR Omer Moysard,
Brussels, Belgium Application September 19, 1933, Serial No. 690,065 In Belgium September 23, 1932 7 Claims.
under a spreading member of generally flaring or conical shape.
The principal objects of my invention are to improve the emciency of such carburetors, to render themreliable in operation when the engine is running idle and to enable their operation to be accurately regulated Without taking the carburetor to pieces.
According to my invention, I arrange axially of the jet a central air supply which, owing to the draft induced by the associated engine, promotes the suction of the fuel when running under load, and imparts thereto, when running idle, a regularity of operation hitherto unobtainable with carburetors of this type. Moreover, as the central stream of air spreads around the point of the cone, within the Vannular stream of fuel issuing from the jet, the fuel is divided into very minute particles which intimately mix with the air in the course of the expansionl undergone by the mixture as it flows about the spreading member.
In addition to the central air supply the carburetor may comprise primary and secondary air supplies coaxial with the jet and adapted to be controlled by means of a conical throttle, such as a conical ring axially movable in the choke tube. In this case, according to my invention, the choke tube may form a stop for the throttle and it may also be adjustable axially in order to vary the passage between the throttle and the conical spreading member through which the fuel mixture is4 admitted in reduced amount when the engine runs idle. By adjusting the position of the choke member by means of an eccentric pin or the like operated from outside, the slow or idle motion can be regulated with great accuracy without interfering with the throttle.
In a preferred embodiment of my invention, the conical spreading member is axially adjustable, thus providing a further convenient means for varying the passage for the fuel mixture. Theposition of the conical member may, for example, be distantly controlled by means of an eccentric pin extending through the casing of the carburetor and fitted with suitable means to ensure fluid tightness. y
In the accompanying drawing whichillustrates by way of example a preferred embodiment of my invention:
Fig, 1 illustrates the carburetor in axial section.
Fig. 2 is a side elevation of inside parts of the carburetor.
Fig. 3 is a cross-section on line`3-3 of Fig. 2.
In the drawing, the carburetor casing is formed of three parts I, 2, 3 rigidly connected together 5.
in a detachable manner, part 3 being provided with a flange 4 foi-.connection with the engine inlet manifold. 5 is the air inlet having therein a throttle 6 and 1 is the fuel' inlet pipe which may be connected with a constant level chamber (not shown) for feeding the axial jet 8.
Jet 3 is interchangeable and screws into a sleeve 9 forming with tube I2 an annular fuel duct connected at the bottom with pipe l. Sleeve 9 is carried by a spider I0 clamped between the cas- 15 ing parts YI and 2 which are secured together by i means of threaded ring II.
Extending axially through the sleeve 9 and jet 8 is a tube I2 open at both ends, through which air is freely admitted centrally of the jet while the fuel is sucked through the annular space I3 surrounding the tube I2.
A frusto-conical ring I4 forming a throttle for the fuel mixture is mounted on an axially movable support comprising a pair of vertical rods I5 (Fig, 2) and a crosspiece I6 to which is pivotally connected by means of a link I'I, a bell crank lever I8 the outer arm I9 of which is connected by a rod, a cable or other suitable connection with the accelerator pedal or other con- 30 trol member for the carburetor. The rods I 5 are slidable in sleeves 20 secured to the spider El) and springs 2l are attached to said spider in order to urge the throttle I4 upwards, in the position shown in full lines in the drawing, which corresponds to idle running.
In this position the throttle I4 bears with its lower edge against the tapering wall of the choke tube 22 which is coaxial with the jet 8. The choke tube 22 is slidably mounted in part 2 of the casing and it can be adjusted in position by means of a knob 23 carrying an eccentric pin 24 engaged in a recess 25 in the side wall of the choke tube. Extending through the casing wall 2, knob 23 is rotatable in a boss 26 made integral with a ring clampedaround the casing 2. On said ring is a lug 21 carrying a stop 28 Yadapted to engage an extension 29 of the spindle for the air inlet throttle 6, this arrangement being provided in order to prevent relative motion between parts l and 2 when the ring II is screwed home.
Slightly above the jet 8, in the conical space formed by the flaring portion of the choke tube and the correspondingly flared upper portion of casing 2, is the conical spreader 3B which is supported from a ring 32 by means of helical ribs 3| adapted to impart a whirling motion to the fuel mixture.
Ring 32 is axially slidable in a cylindrical bore 3l formed in the adjacent ends of casing parts 2 and 3 which are clamped together by means of screws 33. Axial adjustment of the ring 32 and cone 3U is controlled by means of a pin 39 engaging `a hole 38 in the cone 3B, which pin is eccentrically mounted on a shaft 40 rotatable in a bushing 4I screwed into the casing wall 2. Shaft 4Q has a close t in bushing 4i and it is made integral with a frusto-conical portion 42 cooperating with a conical seating 44 in the bushing on which, it is tightly pressed by a spring t3, whereby a tight joint is provided and the outside air is prevented from entering the casing when the carburetor is under depression. By means of a Bowden cable or other suitable distant control connected with a lever d? herein shown to be secured to an extension 45 of straft 40, said shaft and with it the eccentric pin 39 may be turned to raise or lower the cone 30 as desired.
Following a constriction just above the chamber 3l, casing 3 flares again to accommodate a check valve 34 for safety against back firing, said valve being slidable on a stem 35 and adapted to be pushed back against the tension of a light yspring 35, so as to seal the carburetor from the pressure of any ignited gases escaping from the engine, thereby preventing the re propagating to the fuel container.
The carburetor above described operates as follows:
When the engine runs under a load, the fuel mixture throttle I4 is depressed by means of lever I9, in a position such as that shown in dotted lines in Fig. l. The central air supply fed through tube I2 into the jet mouth and the primary air current which flows inside throttle I4 suck the fuel at the annular mouth of the jet and carry it into the flaring passage around the spreader cone 3i), where they mix with the secondary air current which passes around throttle I4. By operating throttle I4 the relative size of the primary and secondary air current is regulated according to the running requirements. The central air current issuing from tube I2 is automatically regulated with the primary air current, depending upon the extent to which the passage between the throttle I4 and the point of the spreader 30 has been opened. As shown in Fig. 1, the delivery opening of jet 8 is flush with the deliveryopening oftube I2, so that the fuel issuing from said jet is caught between the primary air current which receives a whirling motion from helical ribs I4 on the inner wall of valve I4, and the central air current which spreads outwardly as it impinges upon the point of member 3D, the jet of fuel issuing from nozzle 8 thus is atomized under such conditions that a very thorough and intimate mixture with the air is ensured.
In the position for idle running, the throttle I4 is held by the springs 2I against the choke tube 22, as illustrated in full lines in Fig. 1. The supply of secondary air thus is cut ofi and the supply of primary air is reduced to a minimum. The draft of the central air supply issuing from tube l2, nevertheless always causes the suction of the fuel from jet 3 to be assured, however slowly the engine may run. The running may be initially regulated by adjusting the choke tube 22, and with it the throttle I Il, by means of the knob 23, to vary the passage' 48- between throttle I 4 and member 30 which controls the amount of fuel mixture 'admitted to the engine. Once the adjustment is made, the choke tube`r 22 may be clamped in position by means of a set screw (not shown) and the ring I I is screwed home'. v v
When it is desired to obtain a Very rich fuel mixture, as for starting the engine, or when the load is Very heavy for example,` lever 4'! may be actuated to raise the spreader 3B", and increase the section of passage 48. The suction from the engine then acts more directly on the jet 8, and increases its output. If the throttle I4 is? in` its upper position the relatively small amount of ai'r 15 admitted through the tube I2 (central supply)l and through the inside of valve I4 (primary supply) forms with the excess fuel a very rich mixture which makes it possible to start the engine when cold and considerably increases its power. The eiect is similar to that obtained in carburetors tted with a starter or with an acceleration pump. Y
The control 41 can also be used to regulate the initial position of spreader 3U corresponding to idle running, so that it may no longer be necessary to move the choke tube 22 for this purpose, and the knob 23 then may be dispensed with.V It will be understood that changes may also be made in the construction herein described and! illustrated, without departing from the scope of my invention as defined by the appended claims'.-
I claim: Y Y
1. In a carburetor, the combination of a casing, a choke tube in said casing, a tapered spreading member projecting downwardly into said choke tube, an annular jet arranged axially under said spreading member, an air supply tube arranged centrally within said jet, the annular opening of said jet being flush with the delivery opening of 40 member in said choke tube, an annular jet ar--45 ranged axially under said spreading member, an; air supply tube arranged centrally of said jet the delivery opening of said jet being flush with the delivery opening of said tube, an air passage surrounding said jet, a throttle valve in the shape of a hollow frustum of a cone, the lower edge of said valve being adapted to engage the Wall of said choke tube, the upper edge of said valve being adapted to co-operate with said spreading member to control the draft in said carburetor, and means for axially moving said valve.
3. In a carburetor, the combination of a casing, a choke tube in said casing, a tapered spreading member in said choke tube forming therewith an upwardly flaring passage for the fuel 60 to cooperate with said spreading member tocontrol the draft of said passage, and means for varying the cross sectional area of said passage.
4. In a carburetor, the combination of a casing, a choke tube in said casing, a tapered spread- `ing member projecting downwardly into said choke tube, an annular jet co-axial` with said the upper edge of said throttle valve being adapted spreading member, means for supplying air cen- 75 trally of said jet, means for supplying air around said jet, an annular throttle co-operating with said choke tube for controlling the supply of air around said jet, means for yieldingly pressing said throttle against said choke tube, and means for axially moving said choke tube in said casing.
5. In a carburetor, the combination of a casing, a choke tube in said casing, a tapered spreading member in said choke tube forming therewith a passage ior the fuel mixture, an annular jet coaxial with said spreading member, means for supplying air centrally of said jet, means for supplying air around said jet, an annular throttle v cooperating both with said choketube for controlling the supply of air around said jet and with said spreading member for controlling the draft in said passage, and means for moving said spreading member relatively7 to said choke tube.
6. In a carburetor, the combination of a casing, a choke tube in said casing, a tapered spreading member projecting downwardly into said choke tube, an annular jet arranged axially under said spreading member, an air supply tube arranged centrally within said jet, an air supply passage-surrounding said jet, an annular throttle in said air supply passage, said throttle being adapted to divide said passage into two concentric air passages, the lower edge of 'said throttle being adapted to engage the wall of said choke tube to cut off the outer of said concentric air passages, a shaft rotatable in said casing, an eccentric pin on said shaft engaging in a recess in said spreading member, means for rotating said shaft and means for providing fluid tightness around said shaft.
7. In a carburetor, the combination of a casing, a choke tube in said casing, a ring slidable in said casing, an inverted cone projecting into said choke tube, helical ribs rigidly connecting said cone with said ring, means for adjusting said ring and cone in position, an annular jet arranged axially under said cone, an air supply tube arranged centrally within said jet, an air supply passage surrounding said jet, an annular frusto-conical throttle in said passage, the lower edge of said throttle co-operating with said choke tube for controlling the supply of air around said jet, the upper edge of said throttle -co-operating with said spreading member for controlling the draft above said jet, and means for axially moving said throttle.