US2122348A

US2122348A - Carburetor

Info

Publication number: US2122348A
Application number: US127254A
Authority: US
Inventors: Machrstrom Anton Georg
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-06-11
Filing date: 1937-02-23
Publication date: 1938-06-28
Anticipated expiration: 1955-06-28

Description

June 28, 1938.

A. G. MAHRSTRGM CARBURETOR Filed Feb. 23, 1937 2 Sheets-Sheet 1 June 28, 1938. A. G. MAHRSTROM 2,122,348

CARBURETOR Filed Febfzs, 1957 2 Sheets-Sheet 2 lll/l/E/VTOR.

Patented June 28, 1938 UNITED STATES PATENT OFFICE Application February 23, 1937, Serial No. 127,254 In Sweden June 11, 1934 3 Claims.

This invention relates to carburetors for internal combustion engines.

The: object of the invention is to provide an efiicient and economical carburetor working perfectly under all conditions.

In the drawings:

Figure 1 is a side View of certain parts of the improved carburetor;

Figures 2 and 3 are vertical sections through the carburetor along planes perpendicular to each other and showing the air and fuel regulating members in, closed position;

Figure 4 is a section corresponding to Figure 3 of certain parts of the carburetor showing the air and fuel regulating members in slightly open position, and

Figure 5 a similar View showing the air and fuel regulating members in a more open position.

The present embodiment of my invention comprises an outer casing I having an axial passageway 2. At its one (upper) end the casing l is: provided with a flange 3 for the connection of the casing to the suction pipe of an internal combustion engine, and at its opposite (lower) end the casing I is in a known manner provided with a float chamber 4. This chamber is provided with a fuel (petrol) inlet 5 and a. float 6 for the regulation of the fuel level. At the end of the carburetor casing I adjacent the float chamber the casing has a bottom I which at a distance from its edge is provided with a socket-shaped portion 8 projecting into the casing l and perforated by a number of openings 9. Through a central opening in the bottom I a tube-shaped member 10 passes projecting down in the float chamber 4 and provided at its lower end with a spray nozzle II for the petrol. The upper portion l2 of the member Iii projects centrally into the casing I and is at its inner end formed with an enlarged head I3, between which and the upper edge of the socket-shaped portion 8 of the bottom I an annular slot or opening I 4 is formed. Within the lower portion of the tube-shaped member In there is centrally inserted a tube l5 with an outer diameter slightly less than the inner diameter of said lower portion of the tube-shaped member It. At the upper end of the tube l5 side openings l6 are provided passing to the annular chamber I1 formed between the upper portion of the tubeshaped member I!) and the socket-shaped portion 8 of the bottom I. To the space between the tubeshaped member It) and thetube I5 there is connected an air supply channel I511 (see Figure 2). This tube I5 is in a known manner perforated by a number of air supply openings (not shown in the drawings) so sized, that fuel flowing from the nozzle II through the tube I5 to the chamber I! will in such a degree be mixed up with air entering through said air supply openings that a rich mixture of fuel and air will be produced. 5 The carburetor casing I is interiorly formed at its one end (near the float chamber) with a cylindrical portion I8 and, at its opposite end, with another cylindrical portion I9 of a smaller diameter. Between said cylindrical portions the cas- 1 ing I is inte-riorly formed with a conical portion 2!). Within the carburetor casing I there is slidably mounted a sleeve 2| provided at its one end with a wider cylindrical portion 22 fitting in the wide cylindrical portion I8 of the casing I and, at its opposite end, with a cylindrical portion 23 of an outer diameter substantially equal to the inner diameter of the narrow cylindrical portion I9 of the casing I. At its upper end the sleeve 2| has a bottom 25 with openings or slots 24 passing therethrough, which bottom carries a guide ring 26 slidable within the cylindrical portion IQ of the casing I. The wide portion 22 of the sleeve 2| is near its open free end interiorly so shaped that on a certain distance, counted in the direction of movement of the sleeve, its diameter will successively diminish in the direction against the said end, so that the annular opening or slot 28 (see Figure 4) formed between the edge of the head I3 and the inner side of the 30 sleeve will successively increase when the sleeve is moved in the direction toward the bottom I. In a similar way the socket-shaped portion 8 projecting from the bottom I is near the bottom I (at 30) so formed that it grows wider in the direction toward the bottom 1, so that the annular slot or opening 30a formed between the sleeve 2| and the socket-shaped portion 8 will diminish, when the sleeve 2| is moved in the direction toward the bottom I.

The carburetor casing l is provided with a series vof air inlet openings 3| distributed around the casing and admitting the outer air to the annular space 32 between the middle portion of the casing I and the sleeve 2|. To a chamber 33 between the casing I and the socket-shaped portion 8 an air inlet opening 34 passes, and in an air inlet tube 35 communicating with said opening there is provided an air regulating valve 36.

To the sleeve 2| there is fixed a pin 31 (see Figures 1 and 2) the one end of which projects through a longitudinal slot 38 in the carburetor casing I. Near said slot a pin 39 is fixed to the casing, and on said pin there is mounted a twoarmed lever 40 the one fork-shaped arm M of which embraces the projecting end of the pin 31, so that by swinging the lever by means of the other arm 42 in the one direction or the other the sleeve 2| will be moved in the one direction or the other within the casing The device described works in the followin manner:

In the position shown in Figures 2 and 3, in which the sleeve 2| is most remote from the bottom 1, the narrow portion 23 of the sleeve 2| entirely or almost entirely closes the narrow, cylindrical portion IQ of the carburetor casing I, so that supplementary air from the air inlet openings 3|, is prevented from flowing to the suction pipe of the engine. In this position of the sleeve 2| the edge or circumference of the head I3 contacts the inner side of the portion 22 of the sleeve 2|, so that the vacuum in the suction pipe of the engine, which vacuum is transmitted to the interior of the sleeve 2| through the openings 24, can not be transmitted to'the annular chambers l1 and 33. In this position of the sleeve 2| (running light position) fuel is admitted to the interior of the sleeve througha channel 4i! (see Figure 2) passing to the upper side of the head |3 from a channel 44 communicating with the space between the tube I5 and the tube-shaped member Hi.

When moving the sleeve 2| in the direction to-- ward the bottom 1 there arises between the upper edge of the upper, cylindrical portion 23 of the sleeve 2| and the inner side of the carburetor casmg an annular opening or slot (see Figure 4) which increases to a certain limit as said movement proceeds and through which supplementary air from the air inlet openings 3| is admitted to flow to the suction pipe of the engine. Simultaneously as at said movement of the sleeve 2| said opening or slot 45 is formed, an annular opening or slot 28 arises between the head I 3 and the inner side of the wide cylindrical portion 22 of the sleeve, which opening or slot in a similar manner increases as the movement of the sleeve proceeds. Through said opening or slot 218 the vacuum in the interior of the sleeve 2| is transmitted to the chamber I1 inside the socketshaped portion 8 and from there through the openings l6 and the tube l5 to the nozzle The rich .mixture of air and petrol now produced in the tube l5 flows through the openings I6'to the chamber H, where it meets and gets mixed with supplementary air entering through the openings 9, further through the opening or slot I4, where the mixture meets and gets mixed'with further supplementary air coming from the slot 30a, and finally through the slot or opening 28 to the interior of the sleeve 2|, from where the mixture escapes through the openings 24 and together with supplementary air entering through the slot or opening 45 flows to the suction pipe of the engine. I

It is evident that by adapting the shape of the sleeve portion 22 in a'suitable manner in relation to the shape of the portion 20 of the carburetor casing the mutual relation between the size of the opening or slot 45, which determines the admission of air, and the size of the opening or slot 28, which determines the admission of fuel, may be so chosen that for each position of the sleeve 2| the most economical re-- lation between fuel and air' is obtained. The manner in which supplementary air is at different points incorporated with the mixture of fuel tributes to effect an intimate mixture between the air and the fuel.

The outer enlargement 5|] of the socket-shaped portion 8 near the bottom I has for its object to reduce the opening or slot 30a (see Figure 5) when the sleeve 2| is further moved in the direction toward the bottom 1. By this the air admission through said opening will diminish and the vacuum in the chamber I! will increase with the effect that the fuel admission will increase thus effecting a more rich mixture of fuel and air flowing to the suction pipe of the engine. To this position the sleeve 2| is brought on such occasions when it is desired to increase the efficiency of the engine without respect to the economy.

The air inlet valve 36 normally occupies its open position. When starting the engine the valve may occasionally be shut in order to effect a more rich mixture of fuel and air.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. An improved carburetor for liquid fuel comprising a casing provided at its one end with a bottom and at its other end with an outlet for the mixture of air and fuel, a slidable hollow sleeve within said casing adapted to regulate air openings in the walls of the casing and provided with an axial passage, means for moving said sleeve within said casing, a nozzle outside the casing for atomizing the fuel and producing a rich mixture of fuel and air, a channel for conducting said rich mixture through said bottom to an annular chamber formed between a member projecting centrally from the bottom into the casing and a socket-shaped member encircling said central member, an enlarged head at the inner end of said central member, an annular passage-way between said head and the inner edge of said socket-shaped member, another annular chamber between the casing and said socket-shaped member, an air inlet passing to the last-mentioned chamber, and an interiorly conical portion of said sleeve encircling said head, between the circumference of which and said conical portion there is formed an annular pas-' sage-way the size of which varies with the position of the sleeve, and which passage-way forms communication between said annular chambers and the interior of the sleeve.

2. An'improved carburetor for liquid fuel comprising a casing provided at its one end with a bottom and at its other end with an outlet for the mixture of air and fueL a slidable hollow sleeve within said casing adapted to regulate air openings in the walls of the casing and provided with an axial passage, means for moving said sleeve within said casing, a nozzle outside the casing for atomizing the fuel and producing a rich mixture of fuel and air, a channel for conducting said rich mixture through said bottom to an annular chamber formed between a member projecting centrally from the bottom into the casing and a socket-shaped member encircling said central member, an enlarged head at the inner end of said central member, an annular passage-way between said head and the inner edge of said socket-shaped member, another annular chamber between the casing and said socket-shaped member, an air inlet passing to the last-mentioned chamber, means in said inlet for regulating the admission of air, and an interiorly conical portion of said sleeve encircling said head, between the circumference of which and said conical portion there is formed an annular passage-way the size of which varies with the position of the sleeve, and which passage-way forms communication between said annular chambers and the interior of the sleeve.

3. An improved carburetor for liquid fuel comprising a casing provided at its one end with a bottom and at its other end with an outlet for the mixture of air and fuel, a slidable hollow sleeve within said casing adapted to regulate air openings in the walls of the casing and provided with an axial passage, means for moving said sleeve in said casing, a nozzle outside the casing for atomizing the fuel and producing a rich mixture of fuel and air, a channel for conducting said rich mixture through said bottom to an annular chamber formed between a member projecting centrally from the bottom into the casing and a socket-shaped member encircling said central member, an enlarged head at the inner end of said central member, an annular passage-Way between said head and the inner edge of said socketshaped member, another annular chamber between the casing and said socket-shaped member, an air inlet passing to the last mentioned chamber, an interiorly conical portion of said sleeve encircling said head, between the circumference of which and said conical portion there is formed an annular passage-way the size of which varies with the position of the sleeve, and which passage-Way forms communication between said annular chambers and the interior of the sleeve, and channels passing through said socket-shaped member between said annular chambers.

ANTON GEORG MAHRsTRoM.