US1625572A - Carburetor - Google Patents

Description

April 19, 1927.

, W. T. SIMPSON CARBURETOR Filed Sept. 4, 1918 2 sheets -sheet 2 15 the right.

Patented Apr. 19, I

UNITED STATES j PATENT OFFICE.

WARD '1. SIMPSON, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, '.l.0 ALBERT G. DICKINSON, O1 GRAND RAPIDS, MICHIGAN.

GARBUBETOR.

Application filed September 4, 1918. serial no. 252,559.

My invention concerns features relating to a vacuum feed, an atomizing nozzle of special construction, 'a special arrangement'of throttle valve means anterior to the fuel nozzle and other features as will be described hereinafter and particularly pointed out in the claim. In the accompanying drawings V .Figure' 1 -is a side view of a carburetor embodying my invention.

Figure 2 is a plan view. I Figure 3 is a central vertical section. Figure 4 is.a sectional view substantially on the'line H of Figure 2, looking towards,

Figure 5 is a detail view of the nozzle.

In these drawings 1' is the outlet from the carburetor leading to the manifold. The fuel inlet is at 2-and' the air-inlet at 3.

The fuel chamber ,4 is connected to the outlet 1 by a Wide port 5 so that the fuel chamber is subjected to the vacuum existing in the manifold and outlet 1. The feed of the fuel to the fuel chamber from a suitable I 2 reservoir takes place by the vacuum to which the fuel chamber is subjected through the port or opening 5 above mentioned and the amount of fuel drawn in is regulated by a valve 6 controlling the fuel inlet. port 7, said valve being controlled by a float 8 and by counterbalancing means 9, which, like the valve 6, is subjected to the suction or vacuum existing in the chamber 4 due to its connection with the outlet 1 through the port 5.

The floati8 is carried by an arm 10 pivotally mounted at 11, said arm reaching over the upper end of the valve. 6 and extending beyond the same. At or near its extreme end the arm 10 is borne upon by a counterbalancing device which, in the particular construction shown, consists of a plunger 9 operating vertically in a suitable chamber 12 which communicates with. the atmosphere through an opening 13, a body of material 14 pervious to the air being interposed between the piston plunger chamber 12 and the air port 13, this material beingfor instance T felt, held'in place by a screw 15.. This acts as a filtel 'for the air.

The purpose ofhis counterbalance device is to neutralize the tendency of the vacuum to lift the valve 6 from its seat and place the control of the valve 6 under the influence of the lfloat 8 alone. The'vefiect of this arrangement is that the valve 6 will be closed as soon as the predetermined level of fuel is reached in the fuelchamber 4.

The plunger 9 is not intended to affect its counterbalancing action by its weight,

- but it is subjected to the samevacuum pressure, tending to pull it down, that the valve 6 is subjected to, tending to pull it up, and thus the tendency of the Vacuum pressure vto open this valve is neutralized by the same vacuum pressure acting on the plunger 9 and through the lever 0 on the upper end 'of the valve 6, tending to close it.

-The main purpose of this balancing acl;.ti on is'to maintain the fuel approximately at the same level in the fuel reservoir withe outregard to the degree of vacuum existing in the carburetor. It will be noticed that the plunger 9 is of smaller diameter than the inlet valve. is because it is located at the outer end of the lever 10 where its force is multiplied upon the valve. 7

. By he use of this valve, controlling the inlet of the fuel to the fuel chamber, counterbalanced by the vacuum in the carburetor, tendency of the suction of the engine to pull the valve open is neutralized and the the fuel to feed in or to cut it ofl? according as the level of fuel lowers or raises, and by reason of this 'arran ement, the suction of the engine will forci ly pull the fuel into the fuel chamber, when the valve opens, and thus the fuel supply'tank may a lower level than the carburetor.

The fuel passes from the fuel chamber 4; by a needle valve 16, Figs. 2 and 4, into the conduit 17 to the central'chamber or Well 18 from which it passes up into the pipe 19 formin the interior member of the atomizer which also includes the member 20 surrounding the pipe 19 and reaching to a point above the upper end of said pipe 19.

The pipe 19 is of equal interior bore throughout and at its upper end it is provided with a bevelled edge 21 flaring from the center outwardlyto a sharp edge lying in the plane of th exterior of the tube. This pipe is bf cylindrical formexbe located at valve is thus controlled by its float to allow pipe or ternally while the interior of the member is tapered upwardly, forming a taper: ing chamber above the upper end of the 1nterior tube or pipe.

The outer member 20 of the atomizer is seated by its screw threaded end in the interior wall 22 of the casing and communicates with the air passage 23 below this wall or partition. Air to this passage is supplied from the inlet 3 through a port or opening 24 when the throttle valve member member 25 which is located just in rear of the port 24 leading to the passage 23 and to the atomizer. These two valves 25 and 25 are ofthe same character, each being mounted on a shaft as at 27 27, journalled in the casing and both are operated simultaneous- 1y through lever arms 28, 28, on said shafts, and a link 29, the two lever arms being connected by the link 30.

It will be understood that the level of the fuel in the inner tube or pipe 19 will be normally the same as that within the float chamber and as indicated in Figure 3 this will be below the upper end of the atomizer pipes 19 and 20 and the ejector effect of the airrushing through the tapering space between these two tubes is relied upon to lift the fuel, atomize it and eject it into the space 1. This space it will be noticed is free from obstruction of any sort, the valves 25 and 25 being located anterior thereto and hence the atom zed fuel or mixture will pass through this space in the same condition that it leaves the atomizer and no undue condensation will take place as would be the case were the jet rojected against a valve located in line witi the atomizer.

Any condensation that takes place against the walls of this chamber 1 will be caught by the flange or channel 31 and will be di rected back into the fuel chamber 4, by gravity.

The fuel needle valve 16 1S pressed normally to its seat by the spring 82. It IS operated in opposition to its spring so as to open at the same time that the throttle valves 25 and 25 are opened, this being done by a cam 33 on the shaft 27 of the valve 25 operating against roller 34 on an arm 35 which is connected to the stem of the needle valve and finds a fulcrum at 36. For

priming, the arm 35 may be operated inde arm being adapted to press upon the bent lever 35 for o ening the needle valve.

I also 'emp oy means for introducin a gasolene supply for starting when using kerosene in the main fuel chamber, this consisting of a needle valve 38 controlling the supply from the gasolcne inlet 39 to the fuel passage-l7 before mentioned leading to the chamber 18 and the spray nozzle.

This valve 38 is normally ressed to its seat by a spring 40 and it is ifted for the inlet of the gasoline by a bent arm 35 similar to the arm 35 before described. This arm 35 has a roller 34 adapted to be acted upon by the cam 33" when in therange thereof but as shown in Figure 1 it is out of the range of said cam and hence the valve 38 is closed by its spring and is out of service.

When one of the valves 16 or 38 is in service the other one is preferably out of service and in the drawings I show the parts in position so that the valve 16 can be opened simultaneously with the opening of the throttle valves 25, 25". place the valve 88 in service and the other valve 16 out of service in starting I provide manually operated controlling means consisting of a rod 41 leading back to the hand of the operator, from a lever 42 pivotally hung at 43 and having connection by links 44 and 45 respectively withfulcrum carrying yokes 4G and 47 slidable vertically on the guide posts 48 and 48 fixed to the frame. The links 44 and 45 are connected to the lever 42 at separated points so that the movement of the lever 42 will move one slide up and the other down and as these slides carry the fulcrums 36 and 36' for the levers and 35 respectively.one of these slides will be depressed to allow the bent arm 35 or 35, as the case may be, controlled thereby to be lowered and thus be placed out of service because it is beyond the range of the cam 33 or 33'.

The lever 42 is shown in its highest position in Fig. 1, from which point it can swing downward through an angle of approximately 45.

Suitable adjustment may be made for refinement of operation by thumb screws 49 passing through the posts or uide ways 48, 48, and bearing upon the slidable yokes 46 and 47 which carry the fulcrums of the bent arms, viz, the pins 36, 36. By turning screw 49 the oke will be tilted about the pivot provided 44 or 45 and thus the fulcrum 36 or 36' will be initially adjusted.

The posts or guide- ways 48, 48, are mounted to turn about the axis 43 and for adjusting the screws 50 are provided pass To temporarily by the upper end of the link one for each post, one of which is shown at 51. The adjustment of the posts will also adjust the fulcrums 36, 36' in relation to the lever arms which bear thereon.

The adjustment of screw 49 adjusts the needle valve inrelation to its seat. By adjusting the screw 50 the fulcrum of the lever or'35' is adjusted so that the valve will be, given a greater or lesser throw when operated by cam 33 or 33'.

The upper arm 37, as shown in Fig; 2, is wide enough to operate upon either the arm 35 or the arm 35;

It will be seen that two fuel supplies may be used with the same atomizer nozzle, one fuel passing through the float chamber and its supply being maintained at the proper level by a floatcontrolled valve and by a needlevalve and the-other fuel sup ly being controlled by a needle valve whic regulates-its flow direct to the atomizer nozzle.

The fuel returning flange or channel 31 by directing the fuel back to the float chamby the dotted lines :11, y,w, 2.

her will prevent loss of fuel when carburetor is flooded.

of the outer member 20. The bevelled edge of the inner tube being flared outwardly enables the fuel to reach the ascending jet of air directly and without eddy currents being set up. The air jet surrounds a conical space a above the inner tube which is substantially of the shape and size indicated This jet creates a depression within this conical space a which lifts the fuel into the same to thereafter mingle with the air jet and be carried thereby into the mixing chamber. By the lifting force of the vacuum created by the air jet within the space a the fuel will be lifted from the central tube not: withstanding the fact that the fuel in the fuel chamber is subjected to the vacuum in the manifold and engine,

The proportions and relationof the parts suited .to give the best results I have found to be substantially as follows:

The distance that the end of the fuel pipe 19 lies below the upper end of the air pipe 20 is equal to, one and one-half times the diameter vof the fuel ipe. I

Y The upper end of t e exterior tube 20 is flared outwardly from about one-third the distance between its top and the level of the "upper end of the inner .tube 19 in order to prevent a choking effect in the jet at the upperend of the nozzle. The diameter of the upper end of the outer tube 20 is slightly greater than the diameter of the upper end of the inner tube, see the points e and f indicating the diameter of the inner tube. -The diameter of the pipe 20 at the level ed, i. e., in the plane of the upper end of the inner .pipe is such as to glve an area between the pipe 20 and pipe 19 equal to twice that of the area of the upper end of the fuel ipe The conical form of the outer tube is such that it widens towards the base in the proportion of an increase of one inch in iameter for each four. inche sin length. Certain variations are of course permisslble for different kinds, of work to be done.

For instance,-itmay be required to increase the volume of air in respect to the amount of fuel introduced in which case a smaller diameter inner pipe would be employed but in such instance the upper end of the inner pipe would extend nearer to the level of the upper end of theouter i e but within the cone formation indicate y the llnes :v-y, wz. The end of the inner pipe would still be located at a distance below the end of the outer pipe substantially equal to one and one-half times its own diameter. a

At 52 I show a check valve closing towards the mixing chamber to cut off communication between the same and the fuel chamber should the carburetor assume an angular position beyond certain prescribed limits as when mounted on an airplane. This check valve consists of a ball resting upon a light spring 53, the weight of the ball being suflicient to overcome the spring when the carburetor is level or tipped within certain limits, the ball then remaining off of its seat 54. Should the carburetor assume an angular position beyond the limits predetermined upon and gravity therebybe prevented from acting effectively on the ball the spring will force the ball valve to its seat to prevent the fuel from passing directly from the fuel chamber into the mixing chamber and flooding the same.

In idling orstarting the two valves25 and 25 are simultaneously opened slightly together with the needle valve 16, or 38, as the case may be. Under these conditions the suction of the engine will draw mainly through the passage 23 and a depressiofi will 'be created within the end of the atomizer to draw the fuel past the needle valve into the mixing chamber. Now when the engine .is to be speeded up the two valves 25 and 25 will be opened wider together with the needle valve, all working simultaneously, andthe air will pass through the main air intake past the'valve 25 into the mixingchamber but owing to the relative proportion of the main air passage and the branch passage 23 suflicient air will go through the latter passage to create the necessar pull on the fuel at the nozzle, it being un erstood that with the arrangement shown the depression exist ing in the fuel chamber at this time will be less, owing to'the-passage of air to the mixing chamber, and the resistance offered to the action of thedepression within the end of the atomizer will be less.

The main valve 25 and auxiliary valve 25 as before stated are operated simultaneously and for adjusting them in relation to each other the rod 30 may be connected in any of the openings with which the levers 28, 28, are provided these openings being shown in dotted lines in Fig. 3.

- I may introduce water into the carburetor to be sprayed into the mixing chamber with the fuel and for this purpose I have shown at 54' a nipple to which a water supply pipe may lead from any suitable source of supply, such as the radiator or any part of the water circulating system. This nipple is preferably placed in advance of the valve 25 which will enable me to dispense with the use of a needle valve for controlling the water supply. y

The water introduced through this nipple which is at the bottom of the casing will pass into the air passage 23 and thence to the air pipe surrounding the fuel pipe 19 and the action of the air thereon rushing through the space between the pipes 19 and 20 will cause the water to be atomized and discharged in this condition with the atomized fuel into the mixing chamber.

It will be noticed that-there is no restriction of any character in the mixing chamber or the space above the nozzle. There is no restriction here either by the presence of a throttle valve or any other structure, formation, or constriction, as a result of which there will be a strong aspirating effect of the fuel from the nozzle passing across the mouth of the opening 5.

I claim In combination in a carburetor, a housing, a mixing chamber, a fuel chamber closed to atmosphere and in open communication with the mixing chamber in order to subject the fuel chamber to the vacuum created by the engine to draw thereinto fuel from a main supply at a lower level than the carburetor, and an ejector for delivering fuel to the mixing chamber and capable of such delivery against the vacuum existing in the fuel chamber, said ejector having a central fuel tube and a primary air tube, said fuel tube being confined closely throughoi t a considerable portion of its length withi the primary ai'r tube which extends slightl beyond, the fuel tube and which has its inside bore slightly tapered toward its u per end, the passage between fuel tube an its surrounding tube contributing to the primary air a high velocity and confining it,

close against the wall of the fuel tube throughout that portion of said fuel tube which is coextensive with the said primaryair tube, and the space between the primary air tube and the housing forming a secondary air passage, the form of both passages being such that air rushing through them induces cones of intense depression over the fuel tube, and two anterior throttle valves operating in seriatim order to control air to the primary and'secondary air passages, substantially as described.

In testimony whereof, I aflix my signature. WARD T. SIMPSON.

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