US1756431A - Carburetor - Google Patents

Description

A ril 29, 1930. A. MIJARES 1,756,431

' CARBURETOR Filed 0ct.-19, 1926 2 Sheets-Sheet 1 AN/Lo M IJARES 84 INVENTOR BY Maw/m A TTORNE Y Patented Apr.

UNITED STATES ANILO MIJ'ABES, F YCNKERS, NEW YORK a CARBUBETOR Application filed October 19, 1926. Serial No. 142,658.

This invention relates to carburetors of the kind used to inject a mixture of air and gasolene into the manifold of a gas engine of the automotive type, and constitutes an improvement over the carburetor made the subject of an application for patent, Serial #105,718, filed by me on April 30, 1926.

It is the particular object of the invention to provide a carburetor of this type with means which will automatically admit a very rich mixture into the manifold of the engine when starting only, these means simultaneously restricting the air supply to the carburetor.

Other objects will become apparent in the following specification and the accompanying drawin s illustrative of a preferred embodiment 0? my invention, and in which Fig. 1 is a plan view of the carburetor;

Fig. 2 is a longitudinal sectional view of the same, partly in elevation;

Fig. 3 is a fragmentary sectional view along the plane of line 3-3 in Fig. 2;

Fig. '4 is a horizontal sectional view along the plane of line 4-4 in Fig. 2, part of the top flange of the carburetor being shown in dotted lines only; showing the carburetor in a normal position at rest and the air inlet check in a working position in dotted lines;

Fig. 5 is a similar sectional view showing the carburetor in a position while starting the engine;

Fig. 6 is a fragmentary longitudinal sectional view of the gasolene regulating valve 35 in a position which it assumes after the engine is started and is running normally; and

Fig. 7 is a. fragmentary cross sectional View along the plane of line 7-7 in Fig. 5.

Like numbers of reference denote similar arts throughout the several-views and the ollowing specification.

, 10 is a float chamber closed by a cover 12.

At the top of one side of the float chamber is an extension 13, adapted to receive a valve V mechanism operated by a float 1.4 which mechanism consists of the usual float operated valve controlling the supply of gasolene into the float chamber from a gasolcue connection 15 at extension 13 for the purpose of maintaining the gasolene at a constant level within the float chamber. This mechanism is well known in the art and is therefore shown diagrammatically only.

At one side of casing 10, substantially at right angles to inlet extension 13, the casing has an extension 16. 17 is a horizontally disposed duct at the lower part of the extension, communicating with the bottom of the float chamber 10. 18 is a vertically extend ing passage from the duct 17 in communication with a horizontal outlet passage 19 near the top of the extension 16. 20 is another vertical passage, substantially parallel to 18 and located between 18 andthe chamber 10. Passage 20 connects bottom duct 17 with outlet passa e 19. 21 is a restricted opening having a va ve seat for a main gasolene needle valve 22 which extends through passage 20 and is threaded above passage 19 in the extension 16 at 23. 24 is a knurled handle knob of valve 22. The upper end of passage 18, adjacent passage 19, has a restricted opening 25, having a valve seat 26 for an auxiliary gasolene valve 27 which is in threaded engagement with the lower end of passage 18 which is closed fluid-tightly by a packing nut 28 around the valve 27. 29 is a pin through the outwardly projecting end of valve 27 which serves as a handle. Passage 18 is enlarged at 30 above outlet duct 19. 31 is an auxiliary gasolene valve having a main cylindrical portion slidably mounted within the enlarged passage 30. 32 is a downwardly projecting stem of valve 31 terminating in a valve face 33, adapted to seat at the mouth of opening 25 within the passage 19. 33 is a flange around valve 31 of slightly larger diameter than its main cylindrical portion, adapted to slide within a recess 34 partly within extension 16 and partly within a cap 35 in threaded engagement with the extension, which serves as a stop for the top of flange 33. 36is a spring wound around the valve 31 within recess 34 to keep the valve normally in an open position, that is, the passage 25 open, and the flange 33 pressed against the cap 35. Near the top of the valve 31 is an annular groove 37, separating a narrow disk-like portion 38 with rounded edges from the main body of the valve. Screwed into extension 16 at 39 in line with outlet passage 19 is a shank 40. 41 is a bore in shank 40 in line and communicating with outlet passage 19. This shank is reduced in diameter at its end opposite to where it screws into extension 16 and is threaded there at 42 to receive a nut 43. 44 is an outlet at one side of the reduced portion of the shank communicating with bore 41.

45 is a mixer housing of substantially L- shape, consisting of a hollow vertical branch 46 and a hollow horizontal branch 47, both substantially cylindrical in shape. 48 is an air pipe fastened within branch'47 by a set screw 49. The top of branch 46 has an oval shaped flange 50 with bolt holes 51 for connecting the carburetor to the manifold of an automobile engine. 52 are bosses at both sides of branch 46, just above branch 47, bored out to suit the reduced end of the shank 40 which is clamped tightly against them by nut 43 in such a manner that its outlet 44 is located in the center of branch 46 facing the manifold connection. The inside of branch 46 is slightly tapered at 53 where it meets horizontal branch 47.

A check valve 54 consisting of a flat disc is hinged at 55 to the inside of branch 47 near the terminal of the air supply pipe 48. 56 is a valve guide of arc-shape, fastened to disk 54 and extending outwardly of branch 47 through an opening 57. Its outwardly projecting end is turned upwardly at 58 and T-shaped at 59, its edges slanting parallel to each other at 60 and 61. 62 is a spring wound around the guide 56 within branch 46 to keep check 54 normally closed. Branch 47 is somewhat enlarged in diameter at 63 to allow for suflicient air space around the air valve 54.

Mounted horizontally in the branch 46 between shank 40 and flange 50 is a rotatable shaft 64 extending through the branch. 65 is a butterfly valve secured to shaft 64 within the branch 46 for the purpose of regulating its opening. On the end of shaft 64. ex

tending frontwardly of branch 46 is fastened a hub 66 of a lever 67 extending upwardly at 68 anddownwardly at 69. The

upwardly extending end is provided with an eye 70 near its outer end for suitably connecting this end with the throttle lever of an automobile engine. 71 is another eye between 7 0 andhub 66 to which is fastened a rod 72. The side of flange 50 nearest gasolene valve 31 is providedwith an extension 73 to the underside of which ispivotally connected by a pin 74 a cam 75. Cam 75 has a frontwardly extending arm 76 to which is fastened the rod 7 2 which connects it to the upper end of lever 67. Cam 7 5 which is in angular relation to arm 76 is substantially of arcuate shape, its extreme end being thinned at 7'7 and being in a plane which permits the travelling of this thinned part of the cam in the groove 37 underneath the disk 38 at the top of the auxiliary gasolene valve 27. The relationof the cam 75 to the disk 38 is such that it is about away from the same, While the engine is at rest, as shown in Figs. 1, 2 and 4. But when the throttle lever, in starting the car, is moved forward about an inch, the thinned part 77 of the cam will be within the groove 37, as shown in Fig. 5. The lower end of lever 67 is bevelled at,78 so as'to just pass the outer face of the outwardly extending end 59 of the valve guide 56 of air inlet check 54. Normally, while the engine is at rest, the bevelled end 78 of lever 67 is about away from the side of the face. But when cam 75 is moved into groove 37, simultaneously this bevelled end is moved to a position directly in front of the face of guide end 59.

The bottom of the mixer housing 45 is open for the purpose of inserting check valve 54 into its proper place. This bottom'is closed by a top wall 79 of a heating chamber 80, which is flanged to the mixer. housing. 81 is a connection at one side of the chamber to receive an exhaust inlet pipe 82 permitting exhaust from the engine to enter heating chamber 80, and 83 is a similar connection at the bottom furthest removed from connection 81 for an exhaust outlet pipe 84 of smaller size than the inlet pipe to retard the flow of the exhaust.

Above the top wall of the heating chamber the wall of the mixer housing 45 is provided with a lug 85 at one side, having a U- shaped groove 86, as clearly shown in Fig. 3, within which rests a corresponding projection 87 at the lower side of extension 16. This serves solely the purpose of taking the strain off shank 40 when operating the various valves. In assembling, shank 40 is screwed into extension 16 and then the mixer housing 45 is slipped over the shank 4O laterally until itcomes to a stop against the enlarged part of shank 40 adjacent extension 16. In this position, projection 87 engages the U-shaped groove 86 of lug 85. The lock nut 43 is then screwed onto the threaded end 42 of shank 40 connecting the mixer housing and the float chamber section securely together.

The operation of the device is as follows Fig. 2 shows the position of the carburetor before starting the internal combustion en- I gine. The float chamber 10 is kept filled with end 78 of lever 67 clears the path of the outwardly extending portion of the valve guide 56 of the air valve 54, and the thinned portion 77 of cam clears the groove 37 of the auxiliary gasolene valve. In starting, the throttle lever is advanced about an inch, which also causes the lever 67 to be moved forward to a position indicated in dotted lines in Fig. 2, when the butterfly valve 65 will be opened, but the air check valve 54 will be held closed by the bevelled lower end 7 8 of the lever 67, having moved directly in front of the face 59 of the outwardly projecting valve guide 56, as is shown in Fig. 5. Simultaneously, the rod 72 fastened to lever 67 moves the cam 75 into such a position that its thinned portion 77 enters the groove 37 of the auxiliary gasolene valve 31. Because of the air check valve 54 being held closed and the auxiliary gasolene valve being held open in this manner, the suction from the engine draws gasolene from the float chamber 10, through duct 17, opening 21, passage 20, and also passage 18, duct 25. passage 19, thence through bore 41 of the shank from outlet 44, past the butterfly valve 65, into the manifold of the engine, or in other words, while in this position, gasolene is drawn into the engine past the main gasolene valve 22 and the auxiliary gasolene valve 31, while the air check valve 54 is kept closed, so that the mixture introduced into the manifold is at this time a very rich one. As soon as the engine has reached its full speed and is thoroughly warmed up, the throttle lever is returned to its original position and the gas controlled by the foot accelerator, as is well known in the art. \Vhen running at full speed or normally after being warmed up, it is advisable and most economical to inject into the engine a mixture considerably leaner than when starting. This is accomplished automatically in the following manner. As soon as the lower end of lever 67 isreturned to its original position, the suction from the engine opens air valve 54 against the tension of the spring 62, permitting air to enter freely and to mix with the gasolene. Simultaneously, the cam 75 has disengaged groove 87 of the auxiliary gasolene valve 31 which is drawn downwardly by the suction of the engine and against the tension of spring 36, whereby valve face 33 will be seated against the mouth of opening 25 within the passage 19 which causes the gasolene supply to be restricted to that through opening 21 past the main gasolene valve 22 only. It is obvious that thus the amount of gasolene admitted is greatly reduced, and the amount of air drawn in considerably increased, resulting in a leaner mixture. After the engine has been started and the auxiliary valve 31 is closed, as clearly illustrated in Fig. 6, the cam 75 travels in a horizontal plane above that of the top of the valve 31, so that, when the engine is sped up by the foot accelerator, the cam travels above the top of the valve.

Similarly. the head 59 of the valve guide 56 is out of line of travel of the lower end of lever 67, as indicated in dotted lines in Fig. 4. The sides of the head 59 of the valve guide are chain'- fered so as always to present an inclined surface to the lever 67 which then travels either before or behind the head, as the'case may be, thereby preventing breakage.

In cars not equipped with this automatic device for admitting a rich mixture into the engine when starting, an auxiliary gasolene valve was usually opened by independent manipulation of its control mechanism com monly attached to the dashboard ot the automobile. I eliminate such and similar devices entirely and admit the rich mixture when starting only by automatically increasing the gasolene supply and reducing the air supply, and change the mixture automatically to a lean one as soon as the throttle lever, after the engine is started, is returned to its original position.

While I have shown and described a pre fer-red embodiment of my invention, I do not wish to limit myself to the particular construction disclosed. It is obvious that various changes of form, proportion, minor details and combination of parts may be resorted to without departing or sacrificing any of the advantages of the invention, defined in the appended claims.

What I claim as new, is:

1. In a carburetor for gas engines with a throttle lever control, having a float controlled gasolene supply, a main gasolene valve, and an air inlet check valve, an auxiliarygasolene check valve controlling a bypass from the said gasolene supply. means for f preventing closing of the said auxiliary gasolene check valve when the throttle lever of the engine is advanced to starting position, the said means being operably disposed to prevent simultaneously opening of the said air inlet check valve.

2. In a carburetor for gas engines with a throttle lever control, having a float controlled gasolene supply, a main gasolene valve, and an air inlet check valve, an auxiliary gasolene check valve controlling a bypass from the said gasolene supply, a lever mechanism between the said auxiliary valve and the said air inlet check valve operable by the throttle lever of the engine, adapted tc keep the said auxiliary valve open and the said air inlet check valve closed, when the throttle lever is advanced to a starting position.

3. In a carburetor for gas engines with a throttle lever control, having a float controlled gasolene supply, a main gasolene valve, and an air inlet swing check, having an arcuate guide projecting externally of the carburetor proportionately to the travel of the said check, an arm operable by the throttle lever of the engine, adapted to contact with the externall projecting end of the said guide, when t e throttle lever is advanced to 5 starting position, to prevent opening of the said check when in such position. v

4. In a carburetor for gas engines with a throttle lever control, having a float controlled gasolene supply, a main gasolene valve, an air inlet check valve, and a mixing chamber, an auxiliary gasolene check valve for closing a by-pass from the said gasolene supply to the mixing chamber, slidably arranged over the end of the by-pass and adapted to seal its outlet to a passage leading to the said mixing chamber, when subjected to the suction from the engine while running, the said auxiliary valve having near its top a groove, a cam actuated by the throttle lever,

adapted to slide within the said groove of the auxiliary valve, when the throttle lever of the engine is advanced to starting position, to prevent the closing of the said by-pass, when in such position.

5. In a carburetor for gas engines with a throttle lever control, having a float controlled gasolene supply, a main gasolene valve, a mixing chamber, an air inlet swing check having a guide projecting externally of 0 the carburetor, a lever adapted to contact with the externally projecting end of the said guide, when the throttle lever is advanced to starting position, to prevent opening of the said check when in such position, and an auxiliary gasolene check valve for closing a bypass from the said gasolene supply to the mixing chamber slidably arranged over the end of the by-pass and adapted to seal its outlet to a passage leading to the said mixing v4o chamber, when subjected to the suction from the engine while running, the said auxiliary valve having near its top a groove, a cam actuated by the throttle lever, adapted to slide within the said groove when the said lever 5 arm contacts with the externally projecting end of the said guide, to prevent closing of the said by-pass at such time.

In testimony whereof I- have hereunto set 7 my hand. I

v ANILO MIJARES.

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