US1567807A - Carburetor - Google Patents

Description

Dec. 29, 1925'- F. C. MOCK CARBURETOR 1921 4 Sheets-Sheet 1 Filed Augus' 15 cARBpnEToR Filed August 15, 1921 4 sheets sheet 2 Dec; 29, 1925- F. C. MOCK CARBURETOR Filed August 15 1921 4 Sheets-Sheet 5 Dec. 29, 1925- Y F. c. MOCK CARBURETOR Filed August 15,

1921 4 Sheets-Sheerl 4 Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

FRANK C. MOCK, OF CHICAGO, ILLINOIS, ASSIGNbB TO STBOMBEBG HOTOB DEVICES COMPANY OF CHICAGO, ILLINOIS, A CORPORATION OF HJJNOIS.

CABBUBETOB.

Application filed August 15, 1921. Serial No. 492,288.

To all whom it may concern:

Be it known that LFRANK C. Moon, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Carburetors, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

The present invention relates to carburetors, and has particular reference to carburetors for airplane motors.

It is essential to thesuccess of an airplane carburetor that it be capable of delivering fuel to the engine in the proper manner when the plane is at a relatively sharp inclination either in the fore and aft direction or laterallyf For certain maneuvers it is furthermore desirable to maintain the motor running under full power with an uninterrupted feed of fuel thereto when the plane is flying through a 100 or when the plane is flying in an inverte position. It is the fundamental object of the present invention to fulfill these requirements by providing a construction of carburetor which will feed fuel to the motor without interruption when the plane is at a sharp angle or 1s in an inverted position.

i It is a more specific object of the invention to provide a construction of carburetor wherein the float chamber is made operative to feed fuel to the carbureting chamber from either the top or bottom of said float chamber, whereb the float chamber is made caper ble of feeding fuel in either its upright or inverted position. e

A further object is to provide-means for admitting atmos here to the top 'or bottom of the float eham r, depending upon'the-position of the carburetor; or for admitting a predetermined air pressure regulated in accordance with the barometric pressure;

In the accompanyi drawings wherein I have illustrated a pre erred" embodiment of my invention:

Figure one form of the present airplane carburetor, this figure being taken approximately on the plane of the line'1.1 o Figure 2;

Figure 2 is a plan view of this same Figure 3 is a 4 plane 'turi tube 16 is a fuel vada ted to supp 'ing a plurality 1' is a vertical sectional viewrof f detail sectional view. taken on the plane of the line 3-3 of Figure 2; v

Figure 4 is a detail sectional view taken on the plane of the line'4-4 of Figure 2;

Figure 5 is a plan view of another form of my invention embodied in a duplex carburetor;

Figure 6 is a vertical sectional view of the same.

Figure 7 is a fragmentary sectional view taken on the plane of the line 7-7 of Figure 5; and

Figure 8 is a similar view taken on the of the line 88 of Figure 5.

The carburetor illustrated in Figures 1 and 2 is built up of upper and lower casing sections 8 and 9 which join along the line 11, being suitably fastened together by cap screws 12 engaging in gears on the casing sections. The upper casing section 8 defines the usual carbureting chamber 13 having a vertical mixture outlet adapted to be coupled by the flange 14 to the intake manifold. The conventional throttlevalve 15 extends through this carbureting chamber for controlling the flow of mixture therefrom. Venturi tube end of the carbureting chamber 13 by an external flange 17v on the Venturi tube which is adapted to be engaged between opposing shoulders 18 on the upper and lower casing sections. fines a circular air intake 19, which may be suitably flanged at its lower end as indicated at 21 for connection tachment.-

Projecting into the lower end of the Venly the main volume of fuel to e carbureting chamber when the carburetor is in an upright or approximately upright position.- This fuel nozzle is con-- structed of a hollow stem 23 which screws into a hollow boss 24 supported in the center of the ail-intake 19. A nozzle head 25 hav- -of radial fuel ports 26,

The lower casing section 9 de-' nozzle 22 which isv with a supercharger atscrews over the upper end of the stem 23,

- and thereby roportion ports 26- communicating with the bore 1 inthe atomization o the fuel.

flector or petticoat 31 which is adapted to deflect a part of the inrushing air' up through ports 32 into the annular space between the sleeves 28 and 29. From the top of the inner sleeve 28 the air flows downwardly through ports 33in a spacing flange 34, and thence enters the bore 27 of the stem through a series of ports 35. The fuel flow to the nozzle is controlledby an interchangeable plug restriction 36 in the lower end of the stem, this plug restriction opening into a chamber 37 in the lower part of the hollow boss 24. A removable plug 38 affords access to this chamber 37. Fuel is supplied to the chamber 37 through a diagonal fuel passageway 39 which opens into the bottom of the float chamber 41.

The shape, proportions and location of the float chamber are of particular signifihaving its axis horizontal. The cylindrical form of the float results in the float P scntin a constant area of displacement of a uni orm contour to the var ous inclinations of the fuel level. Similarly, the generally cylindrical outline of the float chamber retains the fuel level at substantially the same general height therein in practically all fore and aft inclinations of the carburetor. As shown in Figure 4, the float 42 has pivotal connection through'an .arm 43 with a fixed pivot 44 supported on one of the end walls of the float chamber. nected to the arm 43 and intermediate the pivot 44 and'float 42 is a valve stem 45 carrying a valve 46 which is adapted to control the entry of fuel through the valve port 47. The entering fuel is required to pass through a straining screen 48 which is supported below the removable bonnet 49. I shall not describe this valve mechanism and strainer. in detail, as theessential fea tures thereof form part of the disclosure of the co-pending application of Frank 0. Mock, Charles J. Gustafson and Milton E.

i Chandler, Serial No. 244,231, filed July 10,

191 8, in which application this particular float valve mechanism is specifically described; This float valve is so adjusted that when the carburetor is in an upright position, the fuel level in the float chamber 41 will stand at about the dash and dot level indicated. It will be noted that owing to Conthe formation of the float chamber 41 and its immediate proximity to the carbureting chamber 13, the inclination 'of the carburetor in the plane transverse to the float chamber will result in. only 'a slight varia tion of level of the fuel in the nozzle' 42.- In the other plane the center of buoyancy of the float 42 is arranged in close proximity to the axis of the carbureting chamber so that lateral inclination of the carburetor likewise produces only a small variation of fuel level at the nozzle 22.

Opening into the carbureting chamber 13 through the wall of the, Venturi tube 16 is a second fuel nozzle 51 which is adapted to feed fuel'to the carbureting chamber when the carburetor is inverted or approximately so. As shown in Figure 2, this secondary nozzle has athreaded shank 52 which screws into a bore 53 in a boss or enlargement 54 formed on the lower casing section 9. A collar 55 on the nozzle bears against an internal shoulder in, the end of the bore 53, and the intervening channel 56 between the collar and the threaded portion of the nozzle has communication with the bore thereof through radial ports 57. Communicating with the annular channel 56 in the nozzle is a vertical fuel passageway 58 which intersects a horizontal fuel passage way 58 opening into the float chamber 41. Both these passageways 5858' occur at the juncture plane 11 of the two casing sections, and are simply and easily constructed by forming registering-recesses-in the opposing faces of the casing sections. The secondary nozzle 51 is so' positioned and the interior of the float chamber 41 is so designed, that when the carburetor-is inverted the fuel level (in the upper part of the float chamber) will stand higher than the level of-the secondary nozzle 51. The extent of 'submergence or head of the fuel above the nozzle 51 may be proportioned according to the requirement of the carburetor; if it is desired that the carburetor feed fuel to the carburetin chamber for a relatively long interval 0 inverted position of the carburetor, the head of fuel above'the nozzle 51 can be made relatively high. It may be found desirable however, that the fuel level in the inverted position shall not be so high that it will raise the float and open the fuel valve, this valve being preferably retained closed or substantially closed at this time by the weight of the float.

Air is admitted to the float chamber 41 through a passageway 61 formed in an enlarged portion 62 on the top of the float chamber. This air passageway communicates with the upper part of the float chamber through a valve chamber 63 which intersects the bore 61. The lower end of this valve pocket is provided with a flanged bushing 64 which threads into the lower end' the carburetor is inverted. Air is supplied to the bottom of the float chamber when the carburetor .is inverted through a vertical bore 68 which intersects the horizontal bore 61 and which opens into the bottom of the float chamber through the fuel port 68 and into the bottom of the nozzle through the passageway 39. Forobtaining the proper proportioning of the mixture at the different altitudes, there has risen the practice of controlling the pressure in the float cham her so as to compensate for variations in barometric pressure. This action may be obtained in the present embodiment by the use of a manually or automatically controlled valve for controlling the admissionof air to the float chamber or for controlling the communication of suction from the carbureting chamber to the float chamber, this float chamber control being fully disclosed in the copending application of Frank C. Mock, Charles J. Gustafson and Milton E. Chandler, Serial No. 371,199, filed April 5, 1920. In the present instance I have shown such a float chamber control through the interposition of a plu passageway 61, which'ls adapted to be manually operated by the pilot through a control lever 71.

When the carburetor is upright, air enters the top of the float chamber through the air passageway 61 and valve chamber 63,

and atthis time the operation of the carburetor is typical of that of a conventional design. During thisperiod of operation,

the secondary nozzle 51 may be functioning to create a reduced pressure in the upper part of the float chamber through cooperation with the'valve69. During fore and aftv inclinations of the carburetor, the fuel level is maintained fairly constant in the float chamber and .at the fuel nozzle 22, as before described. Owing to thenarrow float' chamber 41 and its close grouping to the carburetor barrel, the lateral inclination of the carburetor does not produce much change in level at the nozzle. When the air-craft swings into aloop orassumes an inverted position, the'volume of fuel swings into the top part of the float 'chamber and the check valve enga es on the seat 67. The point of entrance 0 the fuel'passageways 39 and '58 into the float chamber are so ositioned relative to each other and to the oat chamber, that as the craft swings into its inverted position, the secondary nozzle 51 willvalve 69in the air come under the fuel level before the fuel level recedes from the primary nozzle 22, so that there is no period of time when'the carthe float chamber, or what is normally the bottom. By virtue of the symmetrical form of the float chamber and the diametrically opposite locations of the air ports 66 and 68 one airport will always remain clear of the fuel level for supplying air to the float chamber when the craft is swinging from an upright to an inverted position or vice versa. When the craft is inverted'prim'ary nozzle 22 is dry, and similarly to the secondary nozzle 51 this primary nozzle may be used for creating a sub-atmosphere in thefloat chamber under the control of the valve 69. To rid the vertical passageway 68 of any fuel which may become trapped therein in swinging from an upright to an inverted position, there may be provided a drain pipe 72 leading away from the end of the air passageway 61 to a point outside of the past the nozzle is generally capable of re- 1 ceiving and volatilizing all of the. fuel discharged therefrom. This nozzle may have a suitable air bleed port 73 opening into the rear thereof, and the nozzle may be otherwise proportioned tov insure that an excessive fuel flow therefrom will not result from the head of fuel effective upon thenozzle inthe fully inverted position.-

The present carburetor may be provided wlth an idling jet and other. similar carbu= retor features, but I Shall-make no specific referencev to these as they have no, direct bearing upon the present invention;

In the duplex construction illustrated in Figures 5 and 6, the carburetor is built up of upper and lower casing sections, 8" and 9 joining along the line 11'. The casing is constructed to form two carburetor barrels 75 and 76 having a common air intake 77 and separate mixture outlets 80. Each carburetor barrel has an individual throttle valve 15 andan individualVenturi tube 16 into which discharges 'a primary; fuelv nozzle 22. These two primary fuel nozzles draw fuel through passageways 78 from a common float chamber 79. This float chamber is formed in the median plane between the carburetor barrels 75 and 76 and has a narrow drum shaped float 81 similar to the again. The top of the float chamber 79 is covered by an arched plate 82 constituting part of the upper casing section 8. For

feeding fuel to the carbureting chamber when inverted there is provided in each car-' buretor barrel a secondary nozzle 51' which opens into the carbureting chamber through the upper part of the Venturi wall.

opens into the upper part of the float I chamber 79. As in the previous embodi-' ment, the secondary nozzles 51"are so positioned and the upper partof the float chamber 79 is so designed that when the carburetor is inverted, the secondary nozzles will be submerged by a certain amount of fuel to maintain an eflective fuel feed to the carburetor barrels for a considerable period.

When the carburetor is upright, the air supply to the upper part of the float chamber is through a vertical passageway 85 which is formed in an enlargement 86 extending along the inner wall of the left hand carburetor barrel 75. The lower end of the passageway 85 opens into the air intake area at a point sufli'ciently far down so that-when thecarburetor is inverted, fuel cannot leak out through the passageway 85' into this intake area. The upper end of the passageway 85 communicates with the upper end of the float chamber throu h a channel 87 formed in the'upper sur ace of the lower casing section 9.

' For supplying air to the bottom of the float chamber .when the carburetor is inverted, there is provided a similar passageway 88 formed in an enlar ement 89 cast on the innerw alloftheright and-barrel76. The lower end-of-the passageway 88 opens into a horizontal passageway 91 which enters the lower part of the float chamber, the upper end of the passageway88 communicating at a point above the normal fuel level with a drill hole 92 which opens into the annular space 93 in back of the right hand Venturi tube 1 6. This annular space connects with the air intake area throu h a hole 94; in the lower periphery of the enturi tube, When the carburetor is inverted theefiective pressure.

in this. air intake area is communicated through the hole 94, space 93' and passageways 92, 88 and 91: into the bottom part of the float chamber above the fuel level therein. It will be noted that both air pas-- sageways 85 and 88 receive air from this air intakearea, thus insuring a point of common air pressure for supplying air to the float chamber in either its upright or inverted positions. Any fuel which these air passageways discharge in clearing themselves is precipitated in a central pocket 95 in the bottom of the lower casing section, from which a drain pipe 96 extends to drain the discharged fuel to any suitable point outside of the fuselage. By the present disposal of the two air ports 87 and 91 on opposite sides of the float chamber in the positions illustrated, one airport will invariably be clear of the fuel for supplying air to the float chamber irrespective of the angle of the carburetor or the swing of the craft.

. Provision is made for introducing a supplementary supply of air into the mixture at points above the Venturi tubes 16 through.

the slotted screens 97-. Supplementary air is supplied to these distributing screens from a supplementary air'chamber 98 which receives air from the main air intake-77 through a vertical intake openin 99 controlled by athrottle valve 100. t will be obvious that various changes may be: made in the general embodiment hereinbefore described without departingfro th essence of the invention.

1 claim:

1. In a carburetor, the'combination of a.

carbureting chamber, a float chamber, means for discharging fuel from said float chamber into said carbureting chamber when said carburetor is inverted, and means for venting air into said float chamber when the latter is upright or inverted.

2. In 'a carburetor, the combination of a carbureting chamber, a float 'chamber,-means for conducting fuel from said float chamber to said carbureting chamber, said means opening into said float chamber at a pluupright, and a second fuel port adapted-to receive fuel from said supply chamber and discharge into said carbureting chamber when said carburetor is inverted, one of said fuel ports serving to transmit suction from said carbureting chamber back to said float- Ehamber when the other port issupplying uel.

4. In an airplane carburetor, the combination of a carbureting chamber, a fuel supply. chamber, fuel as'pirating means opening into said carbureting chamber, a

first fuel passagewa j extending from said aspirating means an opening into said suprality of points for drawing fuel therefrom transmit suction to said supply chamber when the carburetor is upright. I

5. In an airplane carburetor, susceptible to being inverted in zperation, the combination of a carburetor amber, a fuel supply chamber, means for feeding fuel from said fuel supply chamber to said carbureting chamber, and means for maintaining a continuous supply of air'to either the top or J bottom of said fuel su' ply chamber when I either the top or bottom of sai plying said fuel in ectmg the carburetor is uprig t or inverted.

6. In an airplane carburetor, the combination of a carbureting chamber, fuel injecting means discharging into said carbureting chamber, a fuel supply chamber supmeans, air ports opening into the top and bottom of said fuel supply chamber for admitting outside air -thereto when the carburetor is upright or inverted, and means for preventing a leakage of' fuel through one of said air ports. 1

7; In an airplane carburetor, the combination of a carburet'uag chamber,.fuel aspirating means in sai carbureting chamer, a fuel supply chamber feedin said aspirating means, means for feeding el to said irating means from adjacent the top an bottom of said'supply chamber, w ereby a fuel feed is maintalned in either the upright or inverted position of said carburetor, and means for admittin air to pp y chamber in accordance with the position of said carburetor. v

8. In an airplane carburetor, the combination ofa carbureting chamber, a fuel port leading from t supplying fuel thereto, a fuel feed chamber feeding said fuelv port, a first air passageway communicatingwith the bottom of said sup ly chamber and extending to a level higher than" the normal fuel (level therein, and a second air passa eway communicating with the top .-of/ id supply chamber and extending to a point beyond 'the highest fuel level in said supply chamber when said carburetor is inverted.

9. In a carburetor, the combination of a carburetor barrel, a relatively narrow float chamber having generally straight substantially parallel sides, said float chamber being disposed with one of its relatively long substantially straight sides in immediate proximity to said. carburetor barrel, whereby there is'a minimum variation of level at the fuel nozzle in said carburetor barrel with the various inclinations of said carburetor, and a relatively narrow cylindrical float in said chamber controlling the level of fuel therein.

-10. In an air lane carburetor, the combination of a carbureting chamber, a throttle valve controllin the outlet from said chamber, a fuel suppfy chamber, a fuel port leading from one end of said supply chamber to sard carbureting chamber, a second fuel port e other end of said supply chamber to said carburetin ports having separate inlets into said carbureting chamber, one of said ports 'bein effective to suppl fuel from said fuel amber when the ot er port is ineffective means permitting air inlet to said fuel chamber above the fuel therein during .upright or inverted position of said car uretor, the ineffective fuel port actin to create sub-atmosphere in said fuel c amber above the (fuel to cooperate with the air inlet to control' the operation of the carburetor. c

chamber, said In witness whereof, I hereunto subscribe.

'my name this 30th da of Jull 921.

. FhLNK' MOCK.

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