US1972734A

US1972734A - Carburetor

Info

Publication number: US1972734A
Application number: US207137A
Authority: US
Inventors: Firth David
Original assignee: MARVEL CARBURETER CO
Current assignee: MARVEL CARBURETER CO
Priority date: 1927-07-20
Filing date: 1927-07-20
Publication date: 1934-09-04
Anticipated expiration: 1951-09-04

Description

Sept. 4, 1934. D, FIRTH 1,972,734

CARBURETOR Original Filed July 20, 1927 2 Sheets-Sheet 1 Sept. 4, 1934. R H 1,972,734

CARBURETOR Original Filed July 20, 1927 2 Sheets-Sheet 2 Patented Sept. 4, 1934 UNITED STATES David Firth,

Carburetor Company, tion of Indiana CABBURETOR Flint, Mich, assignor to Marvel Flint, Mich, a corpora- Application July 20, 1927, Serial No. 207,137 Renewed May .17, 1934 Claims. (Cl. 261-34) This inventionrelates to certain new and useful improvements in carburetors and more particularly to means for supplying an additional amount of fuel to the mixing chamber of the 5 carburetor when the throttle is opened so as to increase the richness of the mixture for accelerat-ion and to provide means for injecting an additional amount of fuel into the mixing chamber by working the throttle for starting the internal combustion engine to which the carburetor is attached. v I a The primary object of the invention is to give greater acceleration to the engine each time the throttle is opened, by means of a plunger positively connected to carburetor throttle forcing a surplus of fuel thru the nozzles, and a second plunger associated with the first mentioned plunger, continuing to force fuel thru said nozzles after the first mentioned plunger has ceased to operate.

Another purpose of the invention is to feed an extra amount of fuel to the engine intake while the engine is in operation after the throttle is opened, and to continue to doso over a more or less extended period, in order to improve the acceleration of the engine, such auxiliary means first discharging fuel thru one of the carburetor nozzles and immediately afterwards thru both of said-nozzles.

A still-further object is to provide such an auxiliary chamber with a novel piston means actuated by the throttle mechanism, and designed to continue the feeding of an extra amount of fuel to the engine intake for a short time, even after the throttle mechanism has come to rest.

Another object of my invention is to provide means for metering the fuel delivered to the high speed-nozzle controlled by the piston for injecting the fuel to said nozzle whereby the fuel delivered to the high speed nozzle is restricteduntil the throttle is moved into substantially open position. Another object of my invention is to provide means for rendering the auxiliary mechanism more orless'inactive during warm weather by providing means for by-passing the fuel from the auxiliary chamber to the fuel bowl of the carburetor.

With the foregoing objects outlined, and with other objects in view which will appear as the description proceeds, my invention consists in the novel features hereinafter set forth in de- 5 tail, illustrated in the accompanying drawings,

and more particularly pointed out in the appended claims.

Referring to the drawings, 4 v Figure 1 is a) top plan view of a portion of a carburetor equipped with my improvements; Figure 2 is a side view of the same, partly in vertical section; Figure 3 is a detail sectional view of a portion of such carburetor, showing my control valve 'set for summer operations;

Figure 4 is a similar view with valve set for winter working;

Figure, 5 is a view similar to Figure showing a modification;

Figure 6 is a side view of the modified constructions, partly in vertical section; Figure 7 is a fragmentary vertical sectional view of a portion of the carburetorshown in Figures 5 and 6, and with the control valve set for summer working; and 1 Figure 8 is a similar view with the control valve in winter position. In'the embodiment of my invention as illustrated in Figures 1 to 4, I have shown a carburetor of the Marvel type in which a high and. low speed nozzle are employed having a suction controlled valve arranged over the higl: speed nozzle, 1 designating the main fuel chamber or a fuel bowl which is provided with a discharge port2 controlled by a check valve 3 The latter permits the fuel to flow from the chamber to the auxiliary chamber, which will be later described, but prevents the fuel from flowing in the reverse direction. a

The port 2 leads into a conduit 4, closed by a removable plug 5 so that when the plug is removed, access may be had to the check valve or to the port 2 or conduit 4.

the control 1, but

Fuel entering the-conduit travels through the passageway 6 into the auxiliary chamber 7.

As shown, this chamber is preferably integral with the chamber 1 and has a cylindrical bore closed by a threaded cap 8. Movably mounted within the chamber 7 is a solid piston 9 having a stem 10 which is adapted to reciprocate through apacking 11 arranged in the cap 8.

Thethrottle mechanism of the carburetor is pivotally connected to the stem 10 by a link 12, which has its lower end pivotally connected thereto by a -pin 13 so as to form a loose connection between the throttle. mechanism and the stem or piston rod whereby the piston is free to move up and down within the chamber. A supplemental annular piston 14 surrounds the stem 10 and cooperates with the solid piston 9. The supplemental piston has an air passage 15 through the same and this passage is controlled by a check valve 16 which is carried by the supplemental piston within a suitable housing preferably formed integral with the piston as clearly shown and is adapted to be closed by the liquid in the auxiliary chamber when the supplemental piston moves downwardly and to open under atmospheric pressure when the supplemental piston is lifted upwardly by the solid piston 9.

A vent port-17 is placed in the upper end of the two chambers in communication whereby air pressure in both chambers is equalized.

An extension 18 at the lower end of the carburetor is provided with a passageway 19 having internal threads 20 at its upper end to engage the external threads of a nipple 21 forming an economizing jet through which extends a valve 22 carried by valve stem 23 that depends from the lower end of the piston 9 so as to.

form metering means for metering the fuel supplied to the high speed nozzle.

Fuel in the auxiliary chamber may always readily flow without restriction through a conduit 24 into the main nozzle 25 of the carburetor and a predetermined amount of fuel will flow to the high speed nozzle 26 and whenever the piston 9 is in its lower position, fuel to the full capacity will fiow through the jet 21 and passage 19 to the high speed nozzle 26.

It will be seen by this construction that when the throttle lever is in the position shown in Figure 2, the fuel-supplied to the high speed nozzle is metered and as the piston moves downwardly so as to move the valve out of the jet, the stem of thevalve being of less diameter than the valve itself, an additional'amount of fuel is supplied or allowed to flow to the high speed nozzle and as the two pistons cooperate with the chamber so as to force fuel out of the same,

when the throttle is moved into open position so as to cause the pistons to descend, fuel will be injected through these nozzles and will continue to flow.

By the construction thus far described, it will be seen that I have provided means for accelerating the internal combustion engine to which a carburetor constructed in accordance with my invention is attached, said means being of a novel construction and including two pistons which cause the fuel to be injected for a predetermined length of time after the throttle has been moved into open position.

This construction also provides novel means for facilitating the starting of the engine.

In the operation of my device, let us assume that the parts are in the position shown in Figure 2 and that the throttle is closed. As soon then as the throttle is moved into open position, the link 12 will cause the piston 9 to rapidly move downwardly and this will cause fuel to be injected from the nozzle 25 for at this time the valve 22 meters the fuel delivered to the high speed nozzle and the only escape of the fuel from the chamber is through the nozzle 25.

It, of course, being understood that a very smallamount might be forced under pressure past the valve 22. As soon, however, as the piston descends sufficiently to open the valve 22, fuel will be forced from the nozzle 26 to the full capacity of the nozzle and as these are all operated automatically by the movement of the throttle, I am able to inject at the proper time the proper amount of fuel to form the combustible mixture which'will increase the acceleration of the internal combustion engine to which my improved carburetor is attached.

As the piston 9 moves downwardly, the supplemental piston 14 will follow the same by gravity but at a slower speed and as the check valve 16 is closed, the supplemental piston will continue to force fuel through the

nozzles

25 and 26 for a short period of time, even after the throttle has been moved to full open position.

It will be obvious that this extra supply of fuel to the intake of the engine will greatly facilitate the acceleration of the engine so as to supply an additional amount of fuel when most needed.

Should the throttle 'be kept open even after the

pistons

9 and 14 have reached their lowermost positions, the fuel will be drawn through the

nozzles

25 and 26 by the suction exerted in the intake of the engine so as to operate in the ordinary manner.

When the throttle valve is moved towards closed position, the piston 9 is moved upwardly and will carry along the supplemental piston 14 and at this time the check valve 16 will automatically open so that the air valve will travel downwardly through the passageway 15 into lower position in the chamber '7 and thus prevent any undue suction due to the raising of the piston.

As it may not be necessary or desirable to use my auxiliary means during warm weather so as to prevent the same amount of fuel being injected in warm weather as in cold weather, I have provided the carburetor with a by pass means which during the summer will simply feed the fuel from the auxiliary chamber back into the main chamber when the piston is moved downwardly so that only a small amount of fuel will be injected through the

nozzles

25 and 26 as the throttle is moved into open position and it is, of course, understood that the calibration of the by pass in respect to the calibration of the intake to the chamber will control the amount of fuel injected. This by-pass means comprises ports 27 and 28 communicating with a control valve chamber 29. The control valve 30 in this chamber has a passageway 31 which when it registers with the ports 27 and 28 (see Figure 3) permits the liquid fuel to flow from chamber '7 to chamber 1 when the pistons move downwardly so that the greater portion of fuel which ordinarily would be injected through the nozzles of the carburetor is forced back into the float chamber of the carburetor.

When the valve 30 is turned to the position shown in Figure 4, that is, to a point where the port 31 no longer registers with the ports 27 and 28, then all travel of the fuel from chamber 1 to the chamber 7 must be by way of port 2.

To permit ready control of the device, the valve 30 is provided with a handle 32, which may be manually moved by 'the operator to register with a summer indication 33, or a winter indication 34on the cover of the chamber 1.

In the modification of the invention as illusc it " All passageway 21:. into the auxiliary chamber and this passageway has a check valve 3a to prevent the reversal of flow of fuel.

A by-pass 27a.-28a places two points of the passageway 2a at opposite sides of the check valve in communication and this by-pass may be closed by a control valve 30a. The latter has a port 31a for placing the two parts of the bypass in communication.

In Figure 7 the by-pass valve is shown in open position and in Figure 8 it is inclosed position and in this form of the invention, the upper portion of the auxiliary chamber is alwaysin direct communication with the atmosphere through a conduit 17a arranged in the piston rod 10a.

This embodiment of the invention operates similar to the construction shown in Figures 1 to 4 inclusive and, of course, when the control valve 30a is set for winter operation and the pistons 9a and 14a are depressed by the throttle mechanism, fuel will be forced to the low and high speed nozzles 25a and 26a. 4

Obviously, when the handle 32a is set for summer operation, the valve 300. is open and any liquid forced by the pistons, simply travels through the by-pass 27a-28a back to the main fuel chamber.

While I have disclosed embodiments of the invention which have been found practical in commercial operation, I am aware that various changes may be made in the details disclosed without departing from the spirit of the invention as expressed in the claims.

From the foregoing description it will be seen that I have provided a carburetor which, while not limited to the type of carburetor employing a high and low speed nozzle, is especially adapted to be used in connection with this type of carburetor whereby the injecting means cooperates with an econommg device so that fuel is not injected from the high speed'nozzle until the throttle has moved a predetermined distance into open position. I

It is, of course, understood that myimproved construction of piston meansfor injecting the fuel operates to carry out the idea of causing the fuel to be injected for a predetermined length of time after the throttle has been opened, will operate in connection with a carburetor having a single nozzle or any number of nozzles and therefore I do not wish to limit myself to any particular type of carburetor to which my improved construction of injecting means is to be used, as I arii'aware'that many changes can be made without departing from the spirit of my invention.

What I claim is:-

1. In a carburetor adapted to be used with an internal combustion engine having a throttle valve, a nozzle, means for furnishing fuel to said nozzle, a chamber interposed in said means and adapted to contain a relatively small charge of fuel, a check valve permitting the now of fuel into the chamber, but preventing reverse flow of the fuel, a valve controlled passageway by-passing the check valve, means in said chamber actuated by the throttle valve for forcing fuel from the chamber to said nozzle, said means being constructed to continue the forcing of fuel after the throttle valve comes to rest.

2. In a carburetor adapted to be used with an internal combustion engine having a throttle,

an auxiliary fuel feeding chamber, a throttle actuated piston for forcing fuel from the direction for forcing fuel from the chamber,

independently of the first mentioned piston.

3. In a carburetor, an auxiliary fuel feeding chamber, a piston rod in the chamber, a main piston on said rod, a supplemental piston surrounding the rod, and a check valve associated with the supplemental piston and adapted to close under fluid pressure when the supplemental piston moves in one direction.

4. The combination with a carburetor having a mixing chamber, with a throttle valve controlling the outlet thereof, of a high and low speed nozzle arranged to deliver fuel .into said mixing chamber, a main fuel chamber, an auxil-- iary fuel chamber, said auxiliary chamber being in communication with the main chamber and said nozzles, a compound piston movably mounted in said auxiliary chamber for injecting fuel through said nozzles, and means controlled by the movement of said compound piston for metering the fuel passing through said high speed nozzle,

r 5. In a device for feeding fuel to an internal combustion engine, a throttle valve, fuel nozzles, a piston for forcing fuel to said nozzles, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel to the nozzles for a short time after the first mentioned piston has ceased its operation and means associated with said'flrst mentioned piston for metering the supply of fuel to one of said nozzles, said means being adapted to increase the supply of fuel through said noz-' zle as the throttle valve is moved to open position.

6. In a carburetor adapted to be used with an internal combustion engine having a .fuel bowl, a throttle valve and a nozzle, means for feeding fuel to said nozzle from said fuel bowl, a chamber interposed in said means, means actuated by said throttle valve for forcing fuel from said chamber through said nozzle, 'said chamber being in communication with said bowl through an auxiliary passage and a valve in said passage for controlling the passage" of fuel therethrough for regulating the amount of fuel forced through said nozzle.

'7. In a device for feeding fuel to an internal combustion engine having a throttle valve for controlling the passage of fuel to said engine, a plurality of fuel nozzles for progressively feeding 'fuel, a piston for forcing fuel to said noz--' zles, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel to said nozzles for a short time after the first mentioned piston has ceased its operation, and means foroperating said piston by the movement of the throttle valve.

8. In a device. for feeding fuel to an internal combustion engine, a throttle valve, a plurality of nozzles for progressively feeding fuel, a piston for forcing fuel through said nozzles, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel to the nozzles foria short time after the first mentioned piston has ceased its operation and means associated with the first mentioned piston for metering the supply of fuel to one of said nozzles;

9. A carburetor having a carbureting passage,

under compression for injecting fuel through said nozzles into said carbureting passage and means operated by the movement of the throttle valve for metering the fuel injected to one of said nozzles.

10. A carburetor having a carbureting passage, a plurality of fuel nozzles for delivering fuel into "said passage, a suction operated valve disposed over one of said nozzles, a throttle valve for controlling the outlet of said car bureting passage, a constant level reservoir, a piston for forcing fuel through said nozzles, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel to said nozzles for a short time after the first mentioned piston ceases its operation, means for operating said piston by the move' ment of the throttle and means associated with said piston for metering the supply of fuel to one of said nozzles. 1

11. A carburetor having a carbureting passage with fuel nozzles disposed therein, one of said nozzles terminating in a plane above the other nozzle, a suction controlled valve arranged over the last mentioned nozzle, a constant level reservoir for feeding fuel to said nozzles, a piston for forcing fuel through said nozzles, a throttle valve, means operated by the movement of the throttle valve for actuating said piston, and an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel through said 'nozzles for a short time after the first mentioned piston has ceased its operation.

12. A carburetor having a carbureting passage with fuel nozzles disposed therein, one of said nozzles terminating in a planeabove the other nozzle, a suction controlled valve arranged over the last mentioned nozzle, a constant level reservoir for feeding fuel to said nozzles, a piston for forcing fuel through said nozzles, a throttle valve, means operated by the movement of the throttle valve for actuating said piston, an auxiliary piston associated with .the first mentioned piston and functioning to continue to force fuel through said nozzles for a short time after the first mentioned piston has ceased its operation, and means associated with the-first mentioned piston for metering the supply of fuel to said nozzles.

13. A carburetor having a carbureting passage, 21. throttle valve mounted therein, high and low speed nozzles disposed in said carbureting passage, a constant level reservoir for constantly supplying fuel to said nozzles, a suction operated valve arranged over the high speed nozzle, a piston for injecting fuel through said nozzles, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel through said nozzles, for a short time after the first mentioned piston has ceased tle valve, a mixing chamber, high and low speed nozzles delivering fuel to said chamber, a main fuel chamber, an auxiliary chamber in communication with said main fuel chamber and said nozzles, a compound piston Working in said auxiliary chamber, a connection between said compound piston and the throttle valve of the carburetor, and means operated by said compound piston for metering the fuel supplied to one of said nozzles.

15. In a device for feeding fuel to an internal combustion engine having throttle mechanism, a fuel nozzle, a-piston actuated by the throttle mechanism of the engine for forcing fuel through said nozzle, an auxiliary piston associated with the first mentioned piston and functioning to continue to force fuel tqthe nozzle for a short time after the first mentioned piston has ceased its operation and means operated by said piston for metering the fuel delivered to said nozzle.

16. In a device for feeding fuel to internal combustion engines having throttle mechanism, a nozzle, a piston rod having a main piston fixed thereon actuated by the throttle mechanism of the engine for forcing fuel to said nozzle, and a gravity actuated supplemental piston loosely mounted on said piston rod above said fixed piston for continuing the forcing of fuel to the nozzle for a shorttime after the first mentioned piston has come to rest.

17. In a-carburetor, a nozzle and a main fuel chamber, a throttle, an auxiliary chamber communicating with the nozzle and the main fuel chamber, a check valve in the line of communication between said chambers to permit the flow of fuel from the main chamber to the auxiliary chamber, but preventing reverse flow of the fuel, a by-pass placing said chambers in communication, a manually operated control valve for said by-pass, and a compound piston composed of two pistons, one movable relative to the other actuated by said throttle for forcing the fuel from the auxiliary chamber to said said piston and normally urged toward the same,

said piston being so formed that the pumping operation of said piston discharges a portion of the fuel above the piston and beneath the said element, said element thereby serving to return the fuel so discharged after the cessation of the pumping motion of said piston to prolong the discharge period of said accelerating device.

20. In a device for feeding fuel to an internal combustion engine, a fuel nozzle, a piston for forcing fuel to said nozzle, a gravity actuated supplemental piston carried by the first men--.

tioned piston, said pistons being movably mounted in respect to one another, said gravity actuated piston being raised by the first mentioned piston and allowed to drop by gravity to continue to force fuel to the nozzle for a short time after the first mentioned piston comes to rest.

21. In a device for feeding fuel to an internal combustion engine having throttle mechanism, a nozzle, a piston rod actuated by the throttle mechanism of the engine provided with a piston for forcing fuel to said nozzle, a gravity actuated supplemental piston carried by the first mentioned piston, said pistons being movably mounted in respect to one another, said gravity actuated piston being adapted to continue to force fuel to the nozzle for a short time after the first mentioned piston comes to rest.

22. In a carburetor adapted to be used with internal combustion engines having a throttle valve, a nozzle, a constant level reservoir, a fuel passage for furnishing fuel to said nozzle from said reservoir, a chamber interposed in said fuelpassage adapted to contain a relatively small amount of fuel, a check valve permitting the flow of fuel into said chamber but preventing a reverse flow of fuel, a piston in said chamber for forcing fuel to said nozzle, a gravity actuated supplemental piston associated with the first mentioned piston, said pistons being movably mounted in respect to one another, said gravity actuated piston being raised by contact with the first mentioned piston and allowed to drop by gravity to continue to force fuel to said nozzle for a short time after the first mentioned piston comes to rest.

23. In a carburetor for supplying a combustible mixture to an internal combustion engine, a throttle mechanism for controlling the flow of mixture to the engine, a nozzle, a fuel supply chamber and a passage leading therefrom 'to said nozzle providing a normal supply of fuel, an auxiliary fuel supply chamber, a main piston in said auxiliary chamber having a connection with said throttle mechanism and moving in response to an opening movement of said throttle to force an additional supply of fuel to said nozzle, a gravity actuated supplemental pistonin said auxiliary chamber coaxial with said main piston and movable relative thereto, said pistons hav ing a direct engagement whereby the supplemental piston is raised and held in potential position by the main piston when the throttle is closed and released when the main piston moves to discharge fuel from the chamber to the nozzle during an opening movement of the throttle, said supplemental piston dropping by gravity after release to continue to force an additional supply of fuel to said nozzle for a short period after said main piston has come to 0 rest. I

24. In a carburetor for supplying a combustiblemixture to an internal combustion engine, a throttle mechanism controlling the flow of com bustible mixture to the engine, a nozzle, a float chamber and a passage adapted to provide -a. normal supply of fuel to said nozzle, a main iston responsive to an opening movement of said throttle to force an additional supply of fuel to said nozzle, and a supplemental piston actuated by gravity and operativelyv associated with said main piston to be raised thereby to potential position when the-throttleis closed, said supplemental piston being released by a discharge movement of said main piston and operating to continue to force an additional supply of fuel to said nozzle for a period after the main piston comes to rest.

25. In a carburetor for supplying a combustible mixture to an internal combustion engine,

a throttle mechanism for controlling the flow of mixture to the engine, a nozzle, a fuel supply chamber and a passage leading therefrom to said nozzle adapted to provide a normal supply of fuel, an auxiliary fuel supply chamber, and a compound piston operating in said auxiliary chamber comprising a main portion having a mechanical connection with said throttle mech anism and moved positively in response to an