Dec. 2, 1947. L. E. OLIVER ET AL 2,431,958 CARBURETOR Filed Nov. 21, 1944 2 Sheets-Sheet 2 ? Z Z l z ZZŠ SN S 19 25 22 ??? a2 * .-..............-.....-................-.........------ ...- N" 2. Z24 NS NVENTORS' zeo Eozitºei Aeavy Carsora Sr. | 36 AttorneyS Patented Dec. 2, 1947 2,431,953 UNITED STATES PATENT of FICE 2,431,958 CARBURETOR Leo E. Oliver, Sanger, and Ray Carson, Sr., Wallejo, Calif. Application November 21, 1944, Serial No. 564,450 16 Claims. (CI. 48—180) 2 This invention is directed to, and it is an ob diagonally disposed when closed as shown in Fig. ject to provide, a carburetor especially designed 1. The shaft 5 is fitted outside body with a lever for use in a motor vehicle fuel System which in to which a control rod 8 connects, said rod ex cludes a fuel reservoir containing a gaseous fuel, tending from the throttle pedal in the operator's Such as natural gas, under high pressure, a con Compartment. duit leading from the reservoir to the carburetor, The body forms the mixing chamber 9 of the and a pressure regulator interposed in the con carburetor, and a tubular, cylindrical housing 0 duit; Such a fuel System being advantageous for projects laterally from body intermediate its automobiles, trucks, motor boats, and aircraft. ends; such housing being initially open at its Another object of the invention is to provide O outer end, and communicating at its inner end a gaseous fuel carburetor which is constructed With chamber 9 directly above the low side of the so as to effectively and economically meter the butterfly valve 6 when the latter is closed. fuel, in correct proportions, at both low and high A tubular sleeve closely and Symmetrically engine speeds; the carburetor including an effec engages in housing 0, and adjacent its outer end tive idling feed to maintain the engine in opera 5 this sleeve is threaded into the housing as at 2 tion when the throttle is closed. for axial adjustment. The sleeve is normally An additional object of this invention is to pro but releasably held in locked position by a nut 3 vide a carburetor which requires no air choke threaded thereon and abutting the adjacent end mechanism for ease of starting. of housing 0. A further object is to provide a carburetor for 20 The sleeve carries the low and high speed gaseous fuel, arranged. So that exterior gas leaks valve assembly, which comprises the following: cannot occur, as all Working parts of the car A tubular plunger 4 is slidably disposed in buretor are Subject to vacuum from the engine. sleeve if with its inner end intermediate the It is also an object to incorporate, in the car sleeve ends; said inner end of the plunger being buretor, a low speed valve, and a high speed valve 25 formed as an annular, radially projecting flange in unique combination; such valves being actu 5 riding in the sleeve. A closure plug 6 is ated in progressive order by a novel cam arrange threaded as at into the housing at its outer ment operated from the butterfly valve support end, and a helical compression spring 8 engages ing throttle Shaft of the device. between said plug and the flange 5 normally These objects are accomplished by means of 30 urging plunger 4 toward body . In the ad such structure and relative arrangement of parts vanced position of the plunger, an annular, taper as Will fully appear by a perusal of the following valve 9 thereon engages a cooperating seat 29. Specification and claims. formed in the inner end of sleeve . This is the In the drawings similar characters of reference high speed valve of the carburetor, and adjacent indicate corresponding parts in the several views: 35 but short of said valve 9 there is space between Figure 1 is a sectional elevation of the improved the sleeve f l and plunger 4 forming a gas flow carburetor, with the low and high speed valves chamber 2 which communicates with the inte closed. rior of plunger 4 by means of a circumferential Figure 2 is a similar view, on reduced scale, but row of ports 2d. in the latter. The inner end por showing the low speed valve Open, 40 tion of plunger 4 projects beyond sleeve to Figure 3 is similar to Fig. 2, but shows both a termination in radial alinement adjacent but the low and high speed valves open. clear of the throttle shaft 5. Figure 4 is a diagrammatic view of the system A mushroom head metering Valve 22 cooperates in which the carburetor is embodied. with an annular taper valve seat 23 formed in Referring now more particularly to the charac 45 plunger 4 at the outer end thereof, and said ters of reference on the drawings, the carburetor valve 22 includes an actuating stem 24 which ex comprises a tubular body open at one end to tends through Said plunger in clearance relation atmosphere and provided at the other end with except at the inner end thereof where a close an attachment flange 2 adapted to connect With running fit is provided; such clearance providing the corresponding fange 3 of an engine manifold 50 a gas flow channel 25. A row of circumferen 4. A throttle shaft 5 extends diametrally through tially spaced ports 26 open through the plunger the body intermediate its ends, and Within Said 4 into channel 25 beyond the sleeve . The body the throttle Shaft carries an air flow control ports 2 a likewise are in communication with butterfly valve 6, mounted as hereinafter de channel 25. It should be noted that ports 2 a. scribed in detail, and which butterfly valve is 55 are of greater diameter than ports 26. 2,431,958 3 4. A compression spring C seats between the head when valves 9 and 22 are closed, by the follow of valve 22 and the plug 6 normally holding Said ing arrangement: valve 22 closed; valve 22 being the slow Speed An air feed duct 34 leads through body par valve of the carburetor. allel to its axis and connects between atmosphere The valve stem 24 terminates beyond the inner and the mixing chamber 9; there being a needle end of plunger 4 and is fitted with an enlarged valve 35 to control air flow through Said duct. head 27. A fiat segmental cam 28 is fixed on Another cylindrical housing 33 projects from throttle shaft 5 radially thereof, with the working body below housing 0, and is closed at its Outer edge of said cam eccentric to the shaft and riding end while its inner end is in communication with the head 2 on valve stem 24; said cam extending 10 a passage 3 leading to duct 34 inwardly of needle valve 35. across the shaft 5 on the side opposite the butter Fuel is fed into the housing 36 by a lateral fly valve 6, and being disposed so that the low conduit 38 leading from fitting 32 through the end of the cam engages head 27 when the butter closed outer end of said housing. Fuel under fly valve is closed. pressure in housing 36 is fed into passage 3 and The butterfly valve is rotatably supported on 15 duct 34 in controlled quantity through the medi the shaft 5 by a hanger H, and all motion of said um of a vacuum actuated, spring returned valve butterfly valve is imparted thereto by the can. unit 39. The valve unit 33 includes an adjust However at opposite ends of the back edge there ment, nut 40 which can be set to insure closing of the cam initially has some clearance from the of the valve against fuel pressure tending to butterfly valve. When the throttle shaft 5 is in 20 carburetor closing position, one end of the back open the same, When the Vacuum falls below edge of cam 28 engages an upstanding compres idling pressurë. sion spring S on butterfly valve 6 and urges the From the foregoing description it will be latter to closed position. (See Fig. 1.) From this readily seen that there has been prodiced such a 25 device as substantially fulfills the objects of the position the throttle valve can rotate to Some ex invention as set forth herein. tent in a clockwise direction without the other While this Specification sets forth in detail end of the back edge of the cam engaging the the present and preferred construction of the de butterfly valve on the opposite side of the shaft vice, still in practice. Such deviations from such 5. The advantage of this.independent movement detail may be resorted to as do not form a de of the cam relative to the butterfly valve will 30 parture from the spirit of the invention, as de hereinafter appear. fined by the appended claims. Gaseous fuel is supplied to the carburetor by a Having thus described the invention, the fol conduit 29 which leads from a tank 30 where the lowing is claimed as new and useful and upon fuel, preferably natural gas, is held under pres 35 which Letters Patent is desired: sure; there being a manually adjustable pressure 1. A carburetor comprising a body forming a regulator 3? interposed in conduit 29, and dis mixing chamber open at one end to atmosphere posed in the operator's compartment. The con and adapted to feed a fuel mixture from the duit 29 is connected to the carburetor by a fitting other end, a butterfly valve mounted for move 32 on and opening through the plug 6.