US1928828A - Carburetor - Google Patents

Description

A. DICKERSON Oct. 3, 1933.

CARBURETOR Filed Aug. 21, 1930 2 Sheets-Sheet l www A. DICKERSON Oct. 3, 1933.

CARBURETOR Filed Aug. 21 1930 2 Sheets-Sheet 2 Ill llll mwrvboa,

Patented Cet. 3, 1933 UNITED STATES PATENT OFFICE My invention relates to carburetion and has for its object to provide a new and economically manufactured carburetor for properly propor-v tioning the air and fuel and vaporizing and 5 breaking up the fuel for an internal combustion engine.

A further object is to provide a carburetor for internal combustion engines which does away with the dash pot commonly used in most car- 10 buretors to cushion the pulsations of the air valve and controlling the air feed by means of vacuum suction and atmospheric pressure combined.

A further object is to provide a carburetor which has the choking thereof controlled by a lever which closes the air bleeder opening and opens atmospheric pressure into a chamber normally held under suction or partial vacuum.

Astill further object is to provide a metering needle controlled partially by direct suction thereon and partially by movement of a cylinder operating against atmospheric pressure or with suction created by a partial vacuum therearound.

These objects I accomplish with the device illustrated in the accompanying drawings in which similar numerals and letters of reference indicate like parts throughout the several views and as described in the specification forming a part of this application and pointed out in the appended claims.

In the drawings, in which I have shown the best and most preferred manner of building my invention,` Figure 1 is a diametrical section of the device. Figure 2 is a diametrical section at right angles to Figure 1. Figure 3 is an inverted plan view of the upper portion or mixing chamber of my device. Figure 4 is a plan View of the float chamber cover and with dotted lines to indicate the air bleeder and the control thereof by the choke lever. Figure 5 is a side elevation. Figure 6 is an end elevation. Figure 7 is a side elevation'of the air control cylinder. Figure 8 is a side elevation of the metering pin. Figure 9 is 45" a plan view of the choke lever.

In the drawings I have shown my mixing chamber as a cylindrical chamber A, having flanges Al formed on the top end by which it is secured to the intake manifold of an internal combustion engine.

The outer perimeter of the chamber A is providedwith bosses A2 extended therebelow and bored and threaded to receive tap screws in holes 3A which hold the chamber A to a oat chamber cover B, but spaced therefrom as shown at C. The internal bore of the chamber A is in two diametered bores l and 2, with the bore 1 adjacent the top end thereof and of smaller diameter than the bore 2. Within the bore l I then provide a cylinder 3, which cylinder 3 has the outer perimeter tapered from the bottom to the top with the top end of smaller external diameter. The said cylinder lits loosely in the bore 1, adapted to be moved longitudinally up and down in the bore l and to allow suction from the bore 1 to draw some degree of air through the annular port 1a around the outer perimeter of the cylinder between the wall of the cylinder and the bore 1, from the chamber 4 formed between the outer wall of the cylinder 3 and the inner wall of the bore 2, and to enclose the said chamber 4 I provide a flange 5 on the lower end of the cylinder, the flange being of the same outer diameter as the diameter of the bore 2, to operate up and down within the bore. On one side of the perimeter of the chamber A, I provide a boss 6, 7

having a vertical bore 7 therein and a port 8 is bored through the boss into the chamber 4 of the bore 2. Within the bore 7 I provide a control valve or stem 9 perforated near the top end thereof at 9A, said perforation adapted to be brought into alinement with the port 8 or to be rotated to close partially or entirely the port 8. The lower end of the stem 9 is turned at right angles to the vertical stem and is provided with a lug 9B, on one side thereof, said lug adapted to open or close a bleeder port 10. The bleeder port 10 is in open. connection with centrally disposed vertical bore 11 of the cover B, and the extreme end of the stem 9 is formed into a control lever l2, which is actuated from the dash of the automobile by a control rod (not shown).

Diametrically across the cylinder 3 I provide a support bar 14, which bar carries a metering pin 15 medially thereon. The said metering pin is slotted at 16, near its top end thereof, and said slot is elongated to allow the pin to move up and down on the bar without any movement of the said bar 14. The lower end of the pin is tapered at 15A and extends down into the bore 11 of the cover B. The cover B is provided with a centrally 1ocated boss 17, which boss has the bore 11 extended down theretllrough with the lower end of the bore threaded at 18. A jet 19 is screwed into the said bore 11 in the threads 18 from the bottom end thereof to such a point that when the lower tapered end of the pin is down into the bore the full amount the jet will surround the pin and there will be just sufficient clearance around the pin 15 in the bore.20 of the jet to allow sufcient fuel to be drawn therethrough to idle the motor and to allow it to run at low speed. The position of the jet may be changed, depending on atmospheric and altitude conditions, by inserting a screw driver into the bore 11 and turning the jet up or down as necessary. The bottom end of the jet is provided with a milled cut 21 to allow for rotation thereof by a suitable tool. On the top side of the cover B I provide an upwardly extended frusto-conical boss 23, which boss has the bore 11 therethrough and the edges of which boss are slightly curved to turn air coming into the chamber between the chamber A and the cover B, and the outer perimeter of the boss receives and acts as a valve seat for the bottom extended end 24 of the cylinder 3 so that when the cylinder 3 is at its lowermost position it is resting on the boss 23 and completely closing all connection with the bore of the cylinder and the bore 1 from the outside atmosphere through the space C. In this position the motor is ready for starting and for idling, as all the air for idling passes through the bleeder port 10 into the bore 11. Ports 25 are bored through the walls of the boss 1'7 into communication with the bore 11 to allow liquid fuel from the float bowl or chamber D to enter the said bore 11.

The float bowl or chamber D is of the usual type having a central bore through the bottom end thereof through which a tap screw or stud bolt 26 is passed, with the upper end of the bolt screwed into the bottom end of the bore 11 to close said end and to hold said bowl to said cover. A float 27 is pivoted within the said chamber and a valve 28 is carried thereon to control the inflow of fuel into the chamber from the elbow connection 29, which is connected with a source of fuel supply.

A butterfly throttle valve 30 is pivoted in the top end of the chamber A on a control rod 3l, which rod has a lever 32 secured on the extended end thereof by which the rod is partially rotated to open or close the valve 30.

The operation of my invention is as follows:

The fuel to be mixed with the air is admitted through check valve 28 into the float chamber D; the float 27 will open and close the check valve 28 and thereby control the level of the fuel in the float chamber. Fuel is then admitted through ports 25 into the bore 11 of the cover extension boss 17, thence through jet 19 into opening 11. Primary air is admitted through port 10 and mixes with the fuel in opening 11 as the fuel emerges through the opening of the jet at 20.

The secondary air supply enters through air space C and the quantity of air that is admitted is controlled by the vertical movement of the cylinder 3, having a seat 24 which contacts with the boss 23 when the cylindrical air valve 3 is in the closed position.

In the normal position with the throttle closed to the idling or starting position the cylinder 3 rests with the end 24 seated on the boss 23, and to start the motor the operator actuates the lever 12 closing the port 10 by the lug 9B and opening the port 8 by bringing the port 9A into alinement therewith. This releases any suction which has been built up around the chamber 4 and holds the cylinder 3 at its lowermost position, allowing the increased suction from the engine to raise the valve 15 the length of the slot 16 on the shaft 14 and thereby drawing increased pure fuel up through the bore 11 from the ports 25 and the float chamber D. When the motor has started and is running idle, the lever 12 is moved to open the port 10 and close the port 8, whether entirely or partially depending upon climatic and weather conditions. The motor may then run idle. To accelerate the motor, the throttle valve 30 is opened the amount desired. This increases the suction through the bore 1 and, as the outer walls of the cylinder 3 are tapered, the suction draws air from the chamber 4, creating or tending to create a partial vacuum therein. The increased suction through the bore 1 lifts the cylinder 3 and the seat 24 from the boss 23, allowing more air to be drawn into the carburetor through the space C between the chamber A and the cover B of the iioat chamber D, and at the same time raising the tapered metering pin l5 in the jet 19, allowing more fuel to pass through the bore 20 thereof, increasing the speed of the motor.

The lever 9A will cover port 10 when in an extreme starting position for the purpose of controlling the quantity of primary air that is admitted. After motor is started, lever 9A is moved to running position, thereby closing port 8. As motor is accelerated, the suction in chamber 1 through the port la becomes effective in the vacuum chamber 4. Suction through the annular port 1a between cylinder 3 and the bore la is then effective on lower flange 5 and causes cylindrical air valve 3 to raise, which opens the secondary air port C. Upon the opening of the secondary air port, the suction in chamber 1 is partly reduced, thereby allowing fuel valve 15 to return to the normal running position.

As throttle valve 30 is opened wide to accelerate the motor causing cylindrical air valve 3 to raise, the tapered opening into the chamber 4 becomes smaller by reason of the taper on the external surface of the cylindrical air valve 3, said decrease in opening retards the rate at which chamber 4 is exhausted, thereby retarding the rate at which cylindrical air valve will raise.

Upon closing throttle 30, the suction in chamber 1 is reduced thereby allowing cylindrical air valve to return to the starting position.

Having thus described my invention, I desire to secure by Letters Patent and claim:

1. In a carburetor the combination of a casing having two sized bores therein and having bosses formed therearound extended therebelow; a float chamber; a cover for said oat chamber secured to said bosses; said cover having a curved walled frustrum of a cone formed on its top side; a boss formed concentrically on the bottom of said cover; a central bore through both cover and said last mentioned boss; a bleeder air port leading into said bore through said cover; a cylinder carried in the smaller bore of said casing having a flange near the lower end thereof, said flange carried and operating in the larger bore to form a chamber therein, the outer perimeter walls of said cylinder being tapered to the top; a metering pin carried by said cylinder within said central bore of said cover; a fuel jet carried in said vertical bore; ports leading into said vertical bore from said float chamber; means to control the flow of fuel into said float chamber; a throttle valve to control the suction through said casing; a port through the side wall of said casing connecting the interior of the chamber formed above the flange of the cylinder with the atmosphere; and a right-angled control lever, having a lug on one side thereof, to close or open the bleeder port, and having the end perforated to form a port, said port adapted to be brought into alinement with the port through the side wall, and said lever to open said port when said air bleeder is closed, releasing the suction within said chamber, and to close said port when the air bleeder is open,

causing the suction within said chamber formed above the flange of the cylinder to build up commensurate with the suction passing through said casing from the engine.

2. In a carburetor the combination of a casing having two different diametered bores therein; a cylinder having a tapered outer wall operating in said smaller bore by the suction of the engine with a flange on said cylinder operating'in the larger bore, forming a chamber between the flange and the top wall of the larger bore; said chamber having a port through the wall thereof; a metering pin supported slidably on a bar across said cylinder; a float chamber having the cover spaced from the bottom end of the said casing, leaving an air port therebetween; a frusto-conical boss on the top of said cover, with the lower edge of said cylinder adapted to seat thereon to close off all air passing through said cylinder into said casing; a central bore through said boss leading from the fuel in said oat chamber in which said metering pin is operated; a bleeder port leading into said bore; and means to open said port and simultaneously and proportionately close the port into the suction chamber above the flange on the cylinder to vary the suction in the chamber, allowing the cylinder to be moved freely, as desired.

3. In a carburetor the combination of a float chamber; a cover therefor; a casing spaced above said cover; a two diametered bore through said casing; a tapered Walled cylinder operating in the smaller bore leaving an annular port therebetween, said port closing as the cylinder is raised, said cylinder having a flange on the lower end thereof operating in the large bore of said casing; a metering pin controlled by said cylinder to control the ow of fuel into said casing from said float chamber by the up and down movement of said cylinder; and means to break the suction over said cylinder to prevent motion of said cylinder.

ARTHUR DICKERSON.

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