US2951690A - Carburetor structure - Google Patents

Description

Sept. 6, 1960 w. c. EBERLINE CARBURETOR STRUCTURE 2 Sheets$heet 2 Original Filed May 18, 1955 F10. 6 LJ IN VEN TOR.

WILL/AM CHARLES EBERLINE XWM KM A TTORNEVS.

P atented Sept. 6, 1960 CARBURETOR STRUCTURE.

3 Claims. 01. 261-71) This invention relates to a carburetor for use on internal combustion engines.

This application is a division of my co-pendingapplication, Serial No. 509,154, filed May 18, 1955.

The invention may be applied to various types of carburetors and is especially adapted to carburetors for relatively small utility engines such as those used on lawn mowers, small farm and gardening equipment, pumps and the like. a l

I An object of the invention is to provide a generally improved, simple, inexpensive bowl structure-and an improved structure for controlling the fiow of fuel from the bowl for mixing with air.

Generally the invention contemplates a bowl having spaced apart deep and shallow regions with an improved drain cock in the deep region and the fuel outlet positioried at the shallow region for improved separation of foreign matter from the fuel. 'A float controlling the' fuel inlet valve is provided with stop means, preventing it from striking against adjacent parts of the carburetor in order to prolong the life of the float. The mixture control valve is provided with exterior operating means selectively operable to make fine and general mixture adjustments. One form of the invention isshown in the accompanying drawings:

Figure 1, is a side elevational view of a carburetor ac cording to this invention.

FigureZ, is an enlarged sectional view on line 22 of Figure 1. j Figure 3 is a sectional view on line 3-3of Figure 2 illustrating the drain cock structure.

[Figure 4 is an enlarged generally sectional view on line 44 of Figure 1.

Figure 5 is an enlarged, fragmentary, top elevational view illustrating a detent structure for controlling the choke.

Figure 6 is an enlarged generally sectional view on line 6-6 of Figure 1, illustrating the mixture control means with some parts shown in phantom.

T he carburetor shown in the drawings has abody 10 with an air inlet 11, a venturi' 12, and a mixture outlet 13 adapted to be secured to the fuel inlet of an internal combustion engine (not shown). A valve member 14 in inlet 11 provides a choke and another valve member 15 adajacent the mixture outlet provides a throttle. The

adjacent opening 27 and a seal element 32 is preferably interposed between body 10 and top of bowl 25 (Figure 1).

Bowl 25 defines a chamber 35 containing a torus shaped float 36 having one side portion 37 connected to a hinge 38 rotatably secured to body 10 through a pivot 39. Float 36 preferably comprisesa hollow shell formed of thin corrosion resisting metal of the order of .004 to .007 inch thick. Body 10 has a fuel inlet passageway 40 adapted to receive a fuel line 41 and communicating into chamber 35 through an orifice 42 and a passageway 43. A valve member 45 slidable' in passageway 43-has a seal element 46 for opening and closing orifice 42 and has a lower end portion 47 supported by an element 48 on hinge 38.

Hinge 38 has a projection 49 which engages a projection 50 on the body when float 36 is in a downward.

position for a purpose to be described. Chamber 35is vented as by a port 53 in body 10 and a manually op erable valve 54 is provided for cutting off the fuel supply to orifice 42. Valve 54 has a seal member 55 biased downwardly as Figure 1 is viewed by spring 56 and has an operating handle 57.

Bowl 25 is fashioned so that its deepest portion 60 is generally adjacent its periphery and so that its central region 61 is relatively shallow (Figure l). Mixture control means for the carburetor includes a passageway 62 constricted as at 63 to form an orifice opening into passageway 18 and a taper valve member 64 projecting choke and throttle are controlled respectively by exterior through the orifice. Passageway 62 has an intake branch 65 communicating into the shallow central portion of bowl 25 through a port 66. Another branch 67 of passageway 62 communicates into the idling jet passageway 19.

Valve member 64 has an elongate shank 70 projecting through hollow bolt 26 and outwardly of bowl 25. Shank 70 has a threaded connection to a packing gland 71 which is in turn threaded to the interior of bolt 26 as at 72 and which secures packing 73 in place. The outer end of shank 70 is enlarged to form a head 74 which may be turned for advancing and retracting taper valve element 64 for adjusting the size of orifice 63.

A wrench member or lever member 76 is operably connected to head 74 and is detachable therefrom. For this purpose head 74 preferably has a non-circular shape such as the hexagonal shape shown and lever 76 has lugs or projections 77 positioned to engage the sides 780i the head. Shank 70 projects through an opening 79 in the lever member so that the lever is shiftable axially of the shank for selectively engaging and disengaging the lugs and the side faces of head74. A compressed coil spring 80 seating on the lever member and on bowl 25 or washer 30 adjacent thereto biases lugs 77 into engaged relation with head 74.

provided on the edge portion of body 10 (Figs. 1 and 4'):

i The graduations may be numbered as shown in Figure 1 and may comprise indentations as shown in Figure 4 for a detent engagement with a projection 84 on lever 76. The lever may be provided with a projection 85 forming a finger hold for convenient operation.

A drain opening 87 is provided in the deepest portion of bowl.25 and the portions of the bowl defining the open-,

ing arepeened or extruded outwardly 'to form an annular shoulder 88 (Fig. 1). A valve member 89 projects through opening 87 and has a seal member 90 forclosing the opening. Valve member 89 has ahead 91 .at'its outer end and a compressed coil spring 92' seats on the head 91 and around shoulder 88 on bowl 25 to: bias the valve toward closed position. Shoulder 88 engages the Tend convolution of spring 92 as shown in Figure Zfoi securing the spring in a generally axially extending position relatively to valve member 89.

Choke lever 16 has a generally circular inner portion 95 providedwith recesses 96, and a small coil spring 97 is attached 'to body and positioned to engage within a recess 96 when in unstressed condition Spring 97 and recesses 96 cooperate to form a detent for positioning choke lever 16 and valve 14 thereon at predetermined positions.

. In handling and shipment of the carburetor prior to its use' on an engine, bowl 25 is empty and float 36 is unsupported except by hinge 38. The float is thus free to swing downwardly as Figure 2 is viewed to the position illustrated in dotted lines. Projection 49 on the hinge engages projection 50 on body 10 to form a stop limiting the downward movement of the float. The float is thus held in a position spaced from the bowl, thereby minimizing damage to the relatively thin metal of the float fromcontact with adjacent parts during handling and shipment.

As to operation of the carburetor, it may be assumed that mixture outlet 13 is connected to the fuel intake of an internal combustion engine (not shown) and that valve 54 is in the open position shown in Figure 2 with operating handle 57 horizontal and seal member 55 elevated. Drain opening 87 is closed by seal element 90. Gasoline entering chamber 35 from fuel .line 41 through passageway 40, orifice 42 and passageway 45 has filled the chamber to the level shown in broken lines 98 in Figure 2 and float 36 has swung upwardly on hinge 38 to the solid line position, raising element 48 and valve member 45 to close orifice 42.

. When the engine connected to mixture outlet 13 is in operation, air is drawn in through inlet 11, passes through venturi 12, and draws raw fuel from chamber 35 through passageway 18, orifice 63, passageway 65 and port 66. The fuel and air are intermixed and pass into the engine from mixture outlet 13. The amount of raw fuel entering the air stream through passageway 18 is regulated by turning head 74 to advance or retract valve member 64 for adjusting the size of the orifice at 63.

To obtain a rough or general adjustment of orifice 63, lever 76 is shifted upwardly as Figure 2 is viewed against the action of spring 80 to disengage lugs 77 from head 74 so that the head and valve member may be freely manually turned. When the desired adjustment has been made, lever 76 is released and shifts downwardly under the action of spring 80 so that lugs 77 re-engage head '74. Fine mixture adjustments may then be conveniently made by manually shifting the easily accessible upper portion of lever 76 to selective alignment with the graduations or detents 83 on carburetor body 10. Lugs 77 engage sides 78 of head 74 in the manner of a wrench for turning the valve member as lever 76 is shifted. Projection 85 provides a finger hold for shifting lever 76. Subsequent adjustments for leaving or enriching the fuel mixture may be made from time to time by turning lever 76 or by shifting the lever upwardly and turning head 74 directly.

Over a period of time foreign matter separates from the fuel in the relatively large quiescent zone provided by chamber 35 in bowl 25. The heavier foreign matter such as water and sediment collects in the deeper, generally peripheral region 60 of the bowl. Port 66 of intake branch 65 lies adjacent the shallow central region of chamber 35 and is thus removed from the sediment collecting region 60 of the chamber so that fuel entering branch 65 for ultimate mixture with air at venturi 12 is largely free of foreign matter.

Drain opening 87 is located in the deep peripheral portion of the bowl to insure complete drainage of the cup when opened. Outwardly extruded annular shoulder 88 adjacent the drain opening provides means for positively positioning the contiguous convolution of spring 92 so that the spring is secured in a generally co-axial position relatively to valve member 89. The spring thus urges valve member 89 straight downwardly as Figure 2 is viewed to seat seal member 90 evenly and securely over drain opening 87 to provide an effective and reliable seal.

From time to time float chamber 36 may be emptied such as for engine maintenance or draining bowl 25 and float 36 will hinge downwardly to the dotted line position shown in Figure 2. Projection 49 on the hinge then engages projection 50 on body 10 to hold the iioat in a position spaced from the bowl, thereby minimizing damage to the float as described above.

What is claimed is as follows:

1. A carburetor comprising, a body, said body having fuel inlet means and air inlet means, said body having mixture control means for mixing fuel and air therein and having mixture outlet means adapted to be connected to the fuel intake of an engine, said mixture control means including a passageway for fuel connecting into said air intake means, and means forming'a valve member, said valve member having a threaded connection to said body and being operable rotatably to regulate the flowof fuel through said passageway, said valve member having aportion projecting outwardly of said body, said outwardly projecting portion having an enlarged portion positioned for direct manual manipulation, whereby to regulate generally the flow of fuel in said passageway, said enlarged portion having an out of round shape, lever means 'con-.

nected to said outwardly extending portion of said valve member, said lever means having lug means mating with said out of round enlarged portion, means forming arcuately arranged graduations on the exterior of said body, said lever means being shiftable to selective alignment with said graduations, whereby to finely regulate the flow of fuel through said passageway, said lug means being detachable from said out of round enlarged portion.

to facilitate free rotation of the latter, whereby selectively to regulate such flow of fuel generally and finely,1 and means to bias said lug means against said enlarged portion and simultaneously to hold said lever means in contact with said serrations.

2. A carburetor comprising, a body, said body having fuel inlet means and air inlet means, said body having mixture control means for mixing fuel and air therein and having mixture outlet means adapted to be connected to the fuel intake of an engine, said mixture control means including a passageway for fuel connecting into said air intake means, and means forming :a valve member, said valve member having a threaded connection to said body and being operable rotatably to regulate the, flow of fuel through said passageway, said valve memmeans overlying and encircling said projecting portion and mating with said out of round enlarged portion, means forming arcuately arranged graduations on the exterior of said body, said lever means being shiftable to selectlve alignment with said graduations, whereby to finely regulate the flow of fuel through said passageway, said lever means being shiftable axially of said outwardly projecting portion of said valve member for detaching said lug means from said enlarged portion, to facilitate free rotation of the latter, whereby selectively to regulate such flow of fuel generally and finely, and spring means seating on said body and on said the lug portion of said lever means, said spring means being stressed to yieldably hold one end of said lever means in operative engagement with said enlarged portion and to hold the f other end of said lever means in yieldable contact with said arcuately arranged graduations.

3. In a carburetor of the type having a body with fuel inlet means and air inlet means, said body having mixture control means for mixing fuel and air therein and having mixture outlet means adapted to be connected to the fuel intake of an engine, said mixture control means including a passageway for fuel connecting into said air intake means, and valve means operable to regulate the flow of fuel through said passageway, that improvement which comprises an operating member on said valve means projecting outwardly of said body and being positioned for direct operating manipulation, whereby to regulate generally the flow of fuel in said passageway, an acircular head on the projecting end of said operating member, a manual control lever having a mounting end encircling said projecting portion of said operating member and engaging said 'acircular head in separable engagement therewith, an extension on said operating lever projecting toward said body shaped to engage spaced serrations in said body selectively, and spring means to hold said encircling portion on and against said head portion and to bias the extending portion of said lever into engagement with said serrations on. said body in various positions of adjustment, said spring permitting relative axial motion of said encircling portion of said lever to permit rotative adjustment between said lever and said operating member and permitting motion of said extending portion of said lever away from said body to permit adjustment of said operating member by said lever to various positions defined by said serrations.

References Cited in the file of this patent UNITED STATES PATENTS 1,196,976 Pembroke Sept. 5, 1916 1,328,590 Royce Jan. 20, 1920 1,394,687 Reid Oct. 25, 1921 1,475,404 Newman Nov. 27, 1923

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