US1547785A - Carburetor - Google Patents

Description

July 28, 1925.

c. cAsPAR GARBURETOR Filed April 15, 1920 INVENTOR ATTORNEY WITNESSES Patented July 28, 1925 v UNITED S A canennmon.

To all/whom it may concern:

Be it known that I, CHARLES H. CA s rAR, a

citizen of the United States, and a resident ,of the city'of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Carburetors, of which the following is a specification,- reference being had to the accom anying drawing, forming a part hereof.

y invention relates to carburetors for use with internal combustion engines. more especially of the automotive type, among the principal objects of the invention being to provide a carburetor adapted for use with fuel or different grades and particularly the less volatile or lower grades of fuel Afurther object of" the invention is to provide in a carburetor means for supplying liquid fuel under any desired pressure and temperature, preparatory to carburetion and means for] preheating the fuel prior to its introduction to the current of incoming air. A still further object of the invention is to provide in a carburetor means whereby the fuel may be retained under pressure prior to vaporiza-- a'dram connection 18 having a valve 19 and with a connection 20 having a check valve tion; to provide -means for automatically varying theamount of fuel admitted to the stream of incoming air in conformity with the velocity of the latter, as well as manually operable means'for increasing the proportion of fuel to the air.

Still further objects of the invention are to provide a'carburetor so constructed as to eliminate liability of flooding and to provide means whereby any danger arising from in-- crease of fuel pressure in the fuel chamber is eliminated, while additionally, the invention. includes all of the other objects and novel features'of construction and arrangetrated or described.

In the accompanying drawing 1. have shown a carburetor constructed ,in accordance with one form of my invention, the sin gle figure being a vertical central section of the device withcertain parts shown in el e vation. I i

The carburetor shown in the drawing comprises a fuel chamber 1 surmounted by a mixing chamber 2 in turn surmounted by a throttle chamber 3 adapted for connection to the intake manifold of an internal combustioniengine. The mixing chamber is provided' with a lateral air intake 4 flaring outparticularly illus- Application nl a'a rn 15, i920. Serial No. 374,066.

PATENT oF.Fic;E.-f

8 and also with a tubular member 9 extendmg through an aperture 10 in the lower part I of the mixing chamber and projecting upwardly in the latter, while a plug 11 of any suitable insulating material provided with exterior threads 14 and including lead wires '12, is screwed into the lower Wall of the fuel chamber so as to extend upwardly therein, the upper ends of the wires 12 being con-- nected with a suitable heating'element 13 extending in the tubular member 9. The lower "end of the plug projects beyond the wall of the-chamber and carries terminals 16 provided with binding screws 17v and connected with the lower ends of the lead wires 12. Through these terminals connections may be made "with a suitable source of current supply, a I i The fuel chambermay be provided with 21, this connection beyond the check valve leading to a hand pump 21 conventionally illustrated which may beused when desired to increase the pressure inthe fuel-chamher. For conducting the fuel to the chamber the latter is also .provided with a connection 22 having a check valve 23 and leading to the main fuel supply while ports 24 and 25 are arranged in the jacket 8 for connection to the pipes through which a heating medium such as hot water or gases from the exhaust may be supp-lied thereto.

gine the liquid fuel is drawn from the fuel chamber through a valve 'port 46 in the upper part of member 9 and hereinafter more particularly referred to which, when During the normal operation of the en-- of the contents thereof or other cause, suitable means are provided conveniently comprising a screw threaded plug 26 positioned in an opening in the mixing chamber wall, arranged to extend into the mixing chamber and to be locked in any desired position by a lock nut 27. This plug is provided with a I central bore 28 in which one end of the valve mixing chamber.

stem 29 of a valve 30 is adapted to slide longitudinally, the other end of valve stem extending into a transverse bore 31 formed adjacent the upper end of the tubular member 9, y The latter is provided with a vertically extending passage terminating in a restricted orifice 33 at its upper end, the orifice and passage connecting the interior of; the member 9 with the interior of the The valve stem 30 terminates in a tapered valve 34 extending across and arranged to normally close the passage 32 and also with a collar 35 between which and the inner end of the plug is positioned a coil spring 36 which constantly urges the valve .34 to closed position.' Thus on the generation of an excessive pressure within the fuel chamber, the valve and valve I stem are forced .to the left when viewed as in the. drawing to openthe passage 32 and the pressure under which the valve will open.

Means area provided for utilizing the stream of air drawn through the inlet tube 4 to effect the admission to the mixing chamber from the fuel chamber of an amount of fuel proportionate to the amount of air drawn into the, former. For this purpose a spider 37 is mounted adjacent the outer end of the tube to support eoaxialtherewith a sleeve 38 in which is threaded an adjusting screw 39 which may be locked in position by a lock nut 40 while at the -inner ,end of the tube and conveniently integral therewith is another spider 41 having aeentral interiorly threaded hub 42." A propeller shaft 43 having threads 44 cooperative with those in the interior .of the hub 42 is provided, the

' inner end of this shaft carrying a tapered or conieal valve 45 cooperative with the port 46 provided in the upper part of the tubular member 9, the other end 47 of the shaft being arranged to slide within a socket 48 m the adJuSting screw 39. Rigidly secured to the shaft is a collar 49 to which is connected one end of a coil spring 50, the other end of which is connected to the adjusting screw in such manner that rotation of the latter within the sleeve 38 will wind up or unwind the spring and thereby increase or decrease the tendency of the spring to rotate the shaft, the-lock nut 40 beingadaptedto hold the screw in any desired position of ad uStment; Between the threads 44 and collar 49 the shaft is preferably provided with a suitable slot 51 adapted to cooperate with a key onthe hub 52 of a propeller 53 in such manner that the hub can slide longitudinallyof the shaft but is constrained to rotate therewith. The propeller comprises a plurality of blades 54 securedto the hub and arranged in suitable angular relation with the axis thereof in such manner that the air sucked past the propeller will tend to rotate the latter, and turn the shaft, in a direction to move the propeller shaft outwardly through coaction of the threads 44 with the hub 42 and thus raise the valve 45 from its seat,the torque exerted by the propeller on the shaft being in a direction opposite to that exerted by the spring. a

.Means are provided for manually moving the propeller longitudinally of 'the shaft when desired, said means preferably comprising a lever 55 pivoted to a bracket 56 conveniently formed integral with the tube 4, one end of the lever having a fork 57 engaging pins 58 carried by the hub 52 while the other end of the lever is connected to one end of a spring 59 the other end of which is connected to the casizhg 3, a control rod 60, also connected with the same end of the lever, leading to any convenient position for manual operation, the arrangement ofvthese several parts beingsuch that the lever may be readily moved from the position shown in full to that shown'in dotted lines or to any intermediate position and thus cause a corresponding movement of the propeller. r

The throttle chamber 3 is provided with the usual throttle 61 with its shaft 62 and operating arm 63 connected with a control rod 64 leading to any convenient position. 1

The arm 63 is provided with stops 65 and 66 adapted to contact with a stop pin 67 carried by the casing, a stop screw 68 being arranged in the stop 66 for contact with the pin 67 in the usual manner.

In the operation of av carburetor of the form hitherto described the fuel is fed through the connection 22v into the fuel cl amber 1 and maintained therein under pressure substantially equal to that within the fuel tank but the pressure in the fuel chamber may be increased when desired through the hand pump cooperative with the connection 20. lVhen a current is passed throughthe heating coil 13 the latter will its capacity for vaporization, the heat supplied from the jacket also contributing to this result, and in case the pressure in the fuel chamber induced thereby should become excessive, the valve 34 will be raised from its seat and the pressure suitably re lieved. i

lVhen the motor is rotated and suction thereby induced in the mixing chamber, a stream of air is drawn into the latter through the tube 4 which, owing to the shape of the tube, increases in velocity as it passes therethrough. Assuming the propeller to be in the position shown'in full lines, in which it is normally maintained by the spring 59, the initial hot-ion of the airis to cause a'slight rotation of the propeller,

heat the fuel in the chamber thus increasing I and in turn the shaft, against the torque of, the spring 50 thereby raising valve 45 slightly from its seat and permitting the fuel to flow from the. fuel chamber into the moving stream of air. As the suction in the manifold is increased through the speeding up of the motor, the air is drawn more rapidly and in greater volume through the tube 4 which tends to turn the propeller further and further in a direction to open the valve 45 and thus increase the flow of fuel in correspondence with the increase in the flow of'air. Additionally, the longitudinal pressure of theair against the propeller tends to simultaneously move the latter inwardly along its shaft and thus progressively bring it into zones in which the air contacts with the blades with increased velocity, thus additionally increasing the torque of the propeller and correspondingly raising the valve 45. It will thus be observed that under normal conditions of operation an increase in the suction exerted by the engine causes, if it may be so termed, a dual effect on the propeller, namely, an increase in its rotation due to the rapidity with which-the air is drawn into the mixing chamber and an additional increase through the bodily inward movement of the propeller by which it is brought to a ,zone in which the air is,

moving at greater speed than adjacent the mouth of the tube 4, both of "these effects tending to lift the valve 45 from its seat zfmd1 correspondingly increase the flow of Moreover, if it be desired at any time to increase the relative quantity of fuel in respect to the amount ofair which would-be normally drawn into the motor at a given motor speed, or, in other Words, to enrich the mixture, the propeller may be moved longitudinally inward along its shaft from any point thereon by actuation of the control rod thereby bringing the propeller into a zone in which the velocity of the incoming air is higher than its initial velocity when it enters the inlet tube, thus increasing the torque of the propeller to lift the valve 45 further from its seat than would be the case were the pr opeller in the position on the shaft which it would automatically assume under the influence of the incoming air alone. Conversely the mixture may be made leaner at any time while the engine is running vby moving the propeller outwardly alon its shaft from the position it may naturally have assumed under the influence of the inspirated air. It will of course be understood that: irrespective of the position of the propeller on the shaft the force}, exerted --on 'the propeller blades by ithe air will cause the latter to rotate only to a point at-which such force is balanced by the torque of the spring 50 and that as the suction of the engine increases or'decreases or as the propeller is'moved 1n and out alongthe shaft undera constant suction, the angular posi- .mixing chamber, and further that at any time proportions of the air and fuel in the mixture may be altered by moving the propelleron the shaft'without varying the vol.-

ume'of the inspirated air thus avoiding the usual choking frequently encountered in other types of carburetors wherein the volume of air is curtailed to enrich the mixture.

While I have herein described and illustrated with considerable particularity a preferred embodiment of my invention, I do not thereby desire or intend to limit myself in any manner to any particular details of construction or arrangement of parts as' suitable changes and modifications may be made therein if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus disclosed my invention what I claim as new and desire to protectvby Letters Patent of the United States is 1. 'In a carburetor the combination of a fuel chamber, a mixing chamber, a valve controlling the admission offuel from the fuel chamber to the mixing chamber, "an air inlet communicating with the. mixing chamber and of decreasing cross sectional area as it approaches the chamber, and means adjustable in, said. tapering alr inlet for varyi g the position of saldvalve in correspond nce with-the flow of air through the inlet.

2. In a'carburetor, the combination of a fuel chamber, a mixing chamber, a valve controlling the admission of fuel from the fuel chamber to the mixing chamber, an air inlet communicating with the mixing chamber and decreasing in diameter as it approache'sthereto, a shaft extending in the inlet and connected with said valve,means-' for moving the shaft longitudinally when rotated, a propeller. rotatable with and longitudinally slidable on the shaft, yieldable means for normally maintaining said propeller adjacent the mouth of the inlet, and adjustable means associated with sald shaft for yieldingly resisting the torque of the propeller on the shaft when an is drawn through the inlet.

3. In a carburetor, the combination of a fuel chamber anda mixing chamber, of an air inlet communicating with'the' latter and of decreasing cross sectional" area as itapvpreaches thereto, a valve controlling. the admission of fuel from the fuel chambento the mixing chamber,a shaft connected wlth said valve, a propeller rotatable with and slidalole longitudinally on the shaft, yieldother thanthat which the-propeller would, able means for normally, maintaining said normally assume under the influence of the propeller adjacent the larger end of the inspirat d a la.

inlet, yieldable ,means for resisting the 'WltIle'S? e I 'hav l fl Set torque of the propeller on the shaft, and y h nd hls 13th day of Apr1l,'192( manually operable means for holding the I p propeller in any desired position on its shaft CHARLES 4 H. GASPAR-

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