US1409420A - Combined gravity and vacuum carburetor - Google Patents

Description

J. A. SPEED.

COMBINED GRAVITY AND VACUUM CARBURETOR.

APPLICATION FILED DEC.2'I, 1919. 1,409,420. Patented 14, 1922;.

3 SHEETSSHEET ln l5: .IW. w H Ill 0 I m F I k 3 ix fi I 5 J. A. SPEED.

' COMBINED GRAVITY AND VACUUM CARBURETOR.

APPLICATION FILED DEc.27.1919.

3 SHEETS-SHEET 2.

1,409,420, 7 Patented Mar.14,1922.

J. A. SPEED.

COMBINED GRAVITY AND VACUUM CARBURETOR.

. APPLICATION FILED DEC. 27. 1919. 1,409,420.

Patented. Mar. 14, 1922.

3 SHEETSSHEET 3. F H H I I I UNITED STAT S PATENT OFFICE.

.mmss A. srmm, or SAN FRANCISCO, CALIFORNIA.

(lOMBINED GRAVITY AND VAGU'UllE CARBURETOR.

To all whom it may co'r'wem:

Be it known that I, JAMES A. SPEED, a citizen of the United States, and a resldent of the city and county of San Francisco, State of California, have invented new and useful Improvements in Combined Gra ity and Vacuum Carburetors, of which the ollowing is a specification.

My invention has for its object the automatic and continuous supply of gasoline, or other hydro-carbon fuel, at all times and 1n accordance with the requirements of an engine in which it is contemplated to use the said fuel, as the well known automobile or internal combustion engine.

As is well known, the use of a hydro-carbon fuel contemplates the mixture of air with the said fuel in a gasified form whereby the explosive mixture is obtained; also, that under different conditions as of load, temperature and humidity, variations in the constituents of the said mixture are frequently advisable In the carburetor of my invention I feed the hydrocarbon fuel from the main supply tank by gravity to the carburetor, unless for any reason, as that due to the change in the relative elevation of the main supply tank and carburetor, the action of gravity is absent or not sufficient to causethe fuel to pass into the carburetor, or is not sufficient to cause the fuel to pass with sufficient rapidity into the "carburetor, in which case the mechanism of my invention operates to produce a negative or vacuum pressure within the carburetor chamber to withdraw the:

fuel from the main supply tank to at all times meet the requirements of the fuel demand through the said carburetor and thus meet the engine needs.

Anotherobject of my invention is to, at all times, proportion thesupply of air for the explosive mixture and fuel quantity in a proper ratio to secure the best possible results from the mixture. These objects I accomplish by utilizing .the suction pressure from the engine through the carburetor to withdraw the fuel from the main tank to the carburetor whenever the rate of flow of said fuel is retarded, due to any cause, as the reduction in relative elevation between the main fuel tank-and the carburetor, and- I provide a form of throttle valve which ad mits under the control of the said valve 'a variable quantity of mixing air, and through Specification of Letters Patent.

4 buretor.

Patented Mar. 14, 1922.

Application filed December 27, 1 919. Serial No. 347,768.

ports controls the providing of a momentary additional fuel supply to secure quicker engine acceleration upon any further opening of the throttle valve, after whichthe rate of flow isautomatically 'reduced to'the point of efficient supply for the newly attained speed or load of the engine. This object I attain by the use of a plurality of supplementary wells within each of which a small supply of fuel is retained until the fuel valve ports communicating with the said wells are opened. Upon the further opening of the throttle valve when accelerating the supply of the corresponding well is instantly admitted, and' until exhausted, after which a previously calibrated or restricted flow of the fuel to the well limits the rate of further fuel supply; the said calibrated or restricted rate, being properly proportioned to the normal engine requirements at the speed or load corresponding with the throttle valve setting communicating with the said well or wells.

Other objects will appear from the drawings and description which follow:

'By referring to the accompanying drawings my invention will/be made clear.

Fig. 1 is a cross section through my car- Fig. 2 is a plan thereof. i

.Fig. 3 is a horizontal section through my carburetor on the line III-III of Fig. 1. Fig. 4 is a section on the line IV-IV of Fig. 1. Fig. 5 is a front view of the throttle face of the well casing 3.

Fig. 6 is a view of the throttle valve and plate. 56 assembled therewith.

Fig. 7 is a right angle view of Fig. 6. Fig. 8- is a cross section of Fig. 1.on the line VIII-VIII.

Figs 9 and 10 are details in section showing variations in the arrangement of the wells and valved means connected therewith.

Fig. 11 is an enlarged section of the up per portion of the chamber 29 and associated parts of Fig. 1.

Throughout the figures the same numerals refer to identical parts. 4

Referring now particularly to Fig. 1, the throttle valve is indicated by the numeral 1, surrounded by the casing 2, which casing is constructed and adapted to assemble with the well housing 3, which I prefer to form with a float chamber 4, within which is provided the usual form of float 5 and valve 6, which latter is adapted to be actuated by the said float to control the port 7. 1

The port 7 receives its fuel through the passage 9 from the duct 10 after passing the check valve 11, preferably mounted in the chamber cover 12. Within this cover, or in other suitable upper portion adjacent the chamber 4, I provide an air vent .13.

The walls of the chamber 4 are provided with a suitable recess as at 14 for receiving the top member 29, within which I mount the secondary float 15, which carries the main valve 16.

spring, as indicated at 17, fromthe said secondary float. Main valve 16 is adapted to normally close vacuum port 18, unless the fuel level sustaining the secondary float 15 drops below a predetermined point, at which time valve 16 is withdrawn from the port 18 and the vacuum, or negative pressure from the passage way 19 is opened through the passage 20, admitting said negative to the secondary float chamber 29.

The main fuel supplyis connected at the fuel inlet 54, from a suitable tank and by suitable pipe connections not shown, but well known, from which inlet the fuel may be passed ,by the check valve 21, passage 22, into the secondary float chamber 29.

At 23 (see Fig. 11) I provide a vacuum check valve, and at 24 a fuel check valve, preferably made of cork. These two latter valves are mounted in tandem in a passageway 25 communicating with vacuum passage 26 by the vacuum valve 27, the latter being normally held open when fuel is supplied to the secondary float chamber 29 by.

gravity, and the said vacuunr'pressure holding the ball 23 agalnst its upper seat 76*allowing air communication through vent 75 to chamber 29. At such time the. main valve 16 is held against the Seat 18.

The vacuum valve 27 closes the vacuum passage 26 due to the falling of the main valve 16, the latter being withdrawn from the port 18, by the secondary float15 whenever the latter drops with a reducing fuel level in the s'econdaryfloat chamber 29.

Connecting'with the float chamber 4 by the duct 30 are a plurality of wells as 31, 32,

pressure I more or less the said channel ways through the thin plate will consecutively expose the said fuel-passage-conduit-outlets admitting communication to the fuel nozzzle 39 from one or more of the said wells 31, 32, 33, 34

according to the engine requirements.

It will be noted that the throttle casing 2 may be assembled about the circular joint 40 in several positions so as to retain the float chambers 4 and-29 vertical, although the engine suction inlet 41 may be in any of several different positions to suit the manifold connections. a

At 42 is provided a suction port co-operating with'the groove 43 in the circular joint 40, which groove communicates by the passage 44 with the vacuum passage 19 of the assembled carburetor.

- Within the wells, as 31, 32, 33,34 (see Fig. 4) I provide screw plugs with cali- Th1s latter I prefer, to suspend by a brated ports 45, which are provided with fuel passages of predetermined size 46, which gine suction.

The air to mix with the fuel is provided through air inlet shown at 47, and the passageway for the said air I prefer to make tapering to a throat at 48, which passageway again tapers outward to the engine suction inlet at 41. The incoming air therefore attains its highest velocity .at 48, just beyond which point is located the fuel nozzle or other fuel. outlet 39. The fuel flowing from the said nozzle is therefore picked up by the inrushing air, while the air is at its maximum velocity, and is then thoroughly atomized and vaporized during its passage 5 upward in the direction of the arrow 49, and

within the tapering passage.

It is to be understood that the throttle 1 is substantially cylindrical, or conical, rotatable about the joint 50, so that the passage from 47 to 41 may be-entirely closed off or opened to any degree by the throttle 1, and that any opening from the fuel nozzle 39 to the engine suction inlet by the joint 50 will provide also a corresponding openin but preferably of slightly less area from t e air inlet to the throat 48. v

, would otherwise occur.

Referring specifically to Figs. 9 and 10,

I prefer to make the dimension 51 slightly greater than the dimension at 52 to compensate for the increased volume due to the vaporization of the fuel. For idling, I prefer to form an air passage as at 53, (see Fig. 8) which is opened by the throttle valve to the throat during such times as there would otherwise be complete closure of the air inlet. It is understood that this passage 53 may be made adjustable in any well known way so as to properly adjust for the idling condition of the particular engine to which the carburetor is being adapted.

- At 55 I have shown a port communicating also with the vacuum passage 19 (see Fig. 1) and an outlet to which passage is in the neck of the throat. This is for the purpose of securing the vacuum draft in the passage 19 at times when the throttle is wide open, or nearly so. Such construction is advisable when the vacuum in the manifold has dropped to an unusual degree asis the case in some engine constructions.

At 56 .(see Figs. 6 and 7) is located a thin plate, having ports as indicated at 82, 83, 84, 85 and which port/s open into the annular grooves 58, 59 of the member 1. These annular grooves are cross connected so that both of them feed to the nozzle 39, the thin plate 56 controlling the fuel flow from the well passages 35, 36, 37, 38 of Fig. 5 into the groove ports 58, 59 in Figs. 7 and 3. The thin plate 56 is provided with a pin, 60, which is adapted to engage with any one of several holes as 61, 62, 63 in the member 1, by which I am enabled to set the throttle 1 and its casing 2 in any required position with relation to the carburetor engine manifold and at the same time retain the relation of the thin plate 56 with its ports to the corresponding face of the well housing '3. The passageway through the member 1 is constructed as shown at 48 (see Figs. 1 and 8) for the purpose of maintaining a relatively high air velocity to facilitate the picking up of the fuel from the nozzle 39, and also causing its rapid volatilization, and the said passage is tapered on each side of said neck or restriction to avoid losses which I have shown at 64 a form of ported screw plug pierced through its center and located in the well as 31, so that upon a demand for fuel being caused by the setting of the valve 1 through the passageway 65 to the nozzle 39, fuel will be first withdrawn from the well through the-opening 66 thus providing an excess fuel for the acceleration period corresponding with the new throttle position, and thereafter fuel will flow throughthe valve inlet at 67 All of the fuel flowing through the passage 64 will find its way into the upper compartment 68 and thence through the passage It is obvious that upon the first demand upon any well being made for fuel, there will be withdrawn some ofthe fuel from the well, resulting in a momentary increased flow therefrom, which I utilize as extra fuel during the acceleration period of the engine to' its new speed, or load. The abstraction of this fuel from the well will. cause a slight negative pressure above the fuel to reduce its rate of flow as the speed due to acceleration is increased, and which is a desirable result. If, however, the volume of air above the fueljn the well is small I prefer to provide a limited or restricted air inlet, thereby permitting the abstraction of the fuel from the well through the nozzle 39 at a greater rate. Such air inlet is not shown but is well known.

Or, the well 31 may be provided with a relatively large air capacity so that the abstraction of fuel upon the opening of the port communicating with the well will permit the expansion under a very low vacuum draft of the said large air volume. Such a relative proportion of Well volume containing the air and the fuel is shown in Fig. 10, or the well may be made shorter and a valve or diaphragm may be allowed to float on the surface 78 so that the fuel contained in 31 as it is abstracted, due to the opening of the corresponding port by the throttle 1, will fall until the said float valve rests upon the pins 79. In such a case the well '31 may be made quite short as to the line 80, and

an air inlet provided as indicated at 81 in dotted lines, the float valve 78 serving as a diphragm, or piston floating on the surface of the fuel and effectually closing the .air passage of the fuel chamber; or other forms of valve or air chamber permitting the abstraction of the fuel in the well and its restoration under gravity from the chamber may be substituted and obtain the same results and I desire to be understood as claiming all such modifications.

If for any reason fuel does not flow into chamber 29 by gravity, float 15 will fall producing, a spring pressure against valve 16,

which pressure when suflicient withdraws the ball 23, closing port 76.

' If fuel flows by gravity through the inlet 54 by the check 21 and through the passageway 22, adequately supplying the chamber 29, the valve '16-is retained upon its seat and fuel will flow into chamber 29 until such time as the float valve 24 is carried by the said fuel to close the port 25.

It will be noted that there is a possible intermediate condition which may exist due to a change in the relative position of the supply tank after the chamber 29 has been filled by gravity, and during which condition the fuel contained in the chamber 29 will be gradually withdrawn through the passage 10 and the ball 23 will be retained upon the seat 7 6 due to the engine operation and maintenance of vacuum in the passage 26, and to permit the withdrawal of the said fuel from the chamber 29 it is necessary to open the said chamber to the atmosphere. This is accomplished by the float valve 24 falling away from the seat 25 thus admitting atmospheric pressure through the passageway 75, so as to allow air to replace the fuel. being withdrawn.

The operation is as follows:

Upon a demand for fuel from the engine and throttle valve 1 being rotated about the joint 50, admitting air as at the inlet 47 and admitting fuel through the nozzle 39 from one or more of the . wells 31, 32, 33, 34, the action will be as above described to supply the excess fuel momentarily, or during the period of engine acceleration and thereafter to restrain the rate of fuel flow through the nozzle 39 to a predetermined required amount to sustain the engtines speed or load. The fuel supply through the nozzle 39 is thereafter supplied from the chamber 4, through the passageway 30, and through one or more of the restricted valved ports of the wells.

When the fuel supply from the chamber 4 has been abstracted to a sufiicient degree float 5 falls withdrawing valve 6 from the port 7 and fuel is then admitted through the passageway 10 by the ball check'll, passage 9 and out through the openings 8, restoring the fuel supply in the chamber 4. 5

When the fuel has been withdrawn from chamber 29--through the passageway 10, as above described, additional fuel is supplied to the chamber 29, either by gravity, supplied through the inlet 54 by the ball check 21, and through passage 22. Or, if for any reason fuel does not flow under the action of gravity in this way to maintain float 15 in its elevated position, the said float 15 will then drop, withdrawing the valve 16 and admitdraw fuel through the passage 22 by the check valve 21 and main inlet supply 54 until the float 15 is raised to the required height to close passage 18 by the valve 16. 7

When the said valve is closed the ball 23 will be retained by the vacuum communicated through the passage 26 upon its seat at 76 and air inlet 7 5 will be opened through port 25 by the valve 24 to the said chamber 29, unless the said chamber 29 is entirely filled with fuel, in which case the valve 24 will float upward and close port 25.

It is to be understood that the throttle valve is to be operated in the well known way by the rotation of the spindle 86, and lever 87, connected to suitable hand or foot controlling devices, not shown. The rotation of the throttle demands a greater or less quantity of carburant, or ex losive mixture to the engine manifold. pon a rotation to a greater opening of the said throttle, the additional carburant is momentarily enriched by the abstraction temporarily of the extra fuel contained in one or more of the wells, and thereafter, assuming the throttle position as not again changed, the rate of fuel flow through the valved or restricted passages from the fuel chamber to the wells, the rate of fuel fiow into the throttle and mixing passages will be such as to establish and maintain a carburant of the most eflicient mixture to sustain the newly acquired engine speed or load.

I claim- 1. In a carburetor,

a substantially c lindrical throttle valve,

having a relatively small passage therethrough, a casing having inlet and outlet passages cooperating with said throttle passage, said inlet passage tapering to the smaller throttle passage and said outlet passage tapering outward therefrom, in combination with a fuel chamber, and an initial fuel chamber, a duct between said chambers, a fuel supply connection to said initial chamber, a float in said initial chamber, a vacuum duct in communication between said initial chamber and the said outlet passage, a valve in said duct actuated by said float when the fuel level therein varies from a predetermined height, a connection between the two chambers and a valve therein actuated by a float, mounted in the fuel chamber whereby the said passage is opened to admit the flow of fuel from the initial chamber to the fuel chamber upon a reduction in the elevation of fuel in the fuel chamber below a predetermined level.

2. A carburetor comprising parts as set forth in claim 1 and a plurality of wells each having a restricted inlet and an enlarged outletand a port through the said throttle and into the small passage therein constructed and adapted to register with one or more of said enlarged outlets depending on the position of the throttle.

3. A carburetor comprising parts as set forthin claim 1 and a plurality of wells each having a restricted inlet and an enlarged outlet and a port through the said throttle and into the small passage therein constructed and adapted to register with one or more of said enlarged outlets depending on the position of the throttle and an independenltly adjustable valve in each rest-rictedwell in et.

In testimony whereof, I have hereunto set my hand at San Francisco. California.

JAMES A. SPEED.

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