US2935977A - Carburetor construction - Google Patents

Description

y 1960 w. c. EBERLINE 2,935,977

CARBURETOR CONSTRUCTION Filed May 6, 1957 3 Sheets-Sheet 1 INVENTOR. WILLIAM C. FBERLINE ATITO NEVS May 10, 1960 w. c. EBERLINE 2,935,977

CARBURETOR CONSTRUCTION Filed May 6, 1957 3 Sheets-Sheet 3 INVENTOR.

ATTORNEYS M/ILL/AM C. EBEELINE Stats;

2,935,977 r CARBURETOR CONSTRUCTION This invention relates to a carburetor and governor control for an internal combustion engine. The carburetor and governor control are particularly adapted for use on utility engines used for farm and home equipment.

It is an object to provide an improved and simplified control.

Drawings accompany the description, and the various views thereof may be briefly described as:

Figure 1, a perspective view of an engine showing the carburetor and governorassembly.

Figure 2, a plan view of the control elements.

. .Figure 3, a sectional view of the carburetor on line 3-3 of Figure 1. i Figure 4, a sectional view of the carburetoron line 4-4 of Figure 3. Y

Figure 5, an exploded view of a control assembly.

Figure 6, an assembled view of the control assembly.

. Figure 7, a sectional view of the assembly shown in Figure 6. g I V Figure 8, an end view of one of the control elements shown in Figure 6.

Figures 9 and 10, sectional views on lines 99 and 10-10 of Figure 7. t

Figure 11, a view of the bottom of the control showing a modified application of a return spring.

Referring to the drawings, an engine is shown in Figure 1 having a cylinder block C and a head H withspark plug provided with a lead wire L. The engine has a flywheel F provided with blades 30. Mounted on the engine block C on a vertical shaft 32 is a governor blade 34 having a plurality of holes 36 for attachment to a control wire 38 leading to a throttle lever 40 on a carburetor 50.

The governor blade 34 is also connected to a pivot arm 52 by a spring 54 which has one end hooked in holes 56 .on the blade 34 and the other end hooked into a tab 58 on pivot arm 52, which is anchored at 60 on the engine block. The arm 52 between the pivot point Y60 and the tab 58 is connected to a wire link 62 which leads to a control on the carburetor 50 being connected in a manner which .will be described in detail to a control assembly generally indicated at 70.

A combination control such as that above described is generally known to the art and has been used on comrnercial devices. The invention herein is particularly related to the carburetor and control assembly which is associated with the governor control.

As shown in Figures 3 and 4, this carburetor consists of a body 74 having an air inlet 76, a venturi 78, and a mixture outlet 80 adapted to be secured to the fuel inlet of the internal combustion engine. A valve member 82 in inlet 76 provides a choke, and another valve member 84 adjacent the mixture outlet .providesa throttle control. .The valve 82 is controlled by the assembly 70, which will be later described, and the valve 84 is mounted on a shaft 86, which projects upwardly through the. housing .and is attached to the lever arm 40. A passagewaySii formed in a cartridge insert 90 forms an opening for raw new? nt r l g e pass y 9 6 ice in the body supplies raw fuel to idling jet 98, which is controlled by a screw needle valve 100. The restricted drilled port at the end of passage 92 is extended throughthe wall of cartridge at 93'. These passages are thus arranged toinsure smooth change-over from idle to run and vice versa. .A bowl 102 is secured on body 74, preferably by a retainer nipple 91 projecting through a central opening 104 in the bowl and threaded to an interior portion in a central bore 106 of the body, into which bore the insert 90 is also threaded at one end.

Suitable sealing washers 108 may be provided adjacent the opening 104, and sealing ring 110 is provided between the top rim of the bowl 102 and an annular recess in the body. Bowl 102 forms a chamber 112 containing a torus shaped float 114 having one side portion 116 connected to a hinge118 pivotally secured to body 74 through a pin 120. Float 114, having inherent buoyancy, may be a hollow shell formed of thin corrosion resisting metal in the order of .004 to .007 inch thick.

Body 74 has a fuel inlet passage 122 adapted to receive a fuel line 124 and communicating into chamber 112 through a bore 126 and a nipple insert 128 threaded into the bottom of the bore. Insert 128 is formed with an orifice 130 at the top end thereof, the inner end of the orifice forming a seat for a bullet-nosed,; square cross sec; tion slide valve 132. l I

This valve has a spherically rounded end 134 at the bottom and is operated by an extension 136 on the end of- Ii valve 132 will close the orifice 130. Hinge 118 has a projection 142 which contacts a small tab 144 to provide-a stop for the downward movement of the float 114. Chamber 112 is vented at with a small air port, and the fuel supply through the passageway 122 and the orifice 130 can be cut off by a plug valve 152, which comprises a spring biased plunger shaft having a recessed end 154 containing a compressible material 156 which engages the end of the insert 128. Shaft 152 projects upwardly through the body and is controlled by an operating element 158 which is a combination lever and cam-throw.

As shown in Figure 3, the valve 152 is in open position. Bifurcate higs' 160 aretransfixed by a pin 162 which passes through the shaft 152. The lugs 160 are formed on the U-shaped operating member 158 having tabs 164 and 166. When these tabs are swung in the direction of the arrows, the corners of the tabs 160 will cam around the pin 162 and raise the shaft 152 slightly and then lower it down to a closed position under the influence of compression spring 168. Plunger 152 is sealed by an O-ring recessed from the top of housing 74 and also by an O-ring and cupped washer assembly 153 whichforms a seat spring 168 at the upper end.

'\It will be seen that this valve 156 closes the inlet to the carburetor float chamber in a positive maner. If it is desired to store or ship an engine, it is possible to drain the float chamber and the entire carburetor will be dry. Also, as will be described later, the valve 156 is closed each time the engine is shut off.

The chamber 112 is connected to the passageway 88 of insert 90 through a plugged bore 169 which leads to central bore 106. A short angled passage 170 connects the float chamber to passage 169 at the bottom of the housing 74. Passage 170 has a plug 171 provided with a metered opening. This arrangement permits a high degree of tiltability of the carburetor. The metered opening or jet in plug 171 is preferably calibrated to a 50% rich condition. This permits adjustable control for altitude and engine variations by a threaded needle valve 17 2.in nipple 91 which controls the bottom end of pasageway 88.; The insert, 90 isrestricted in diameter at its central turn.

portion and provided with cross passageways 1'74 and 176 to permit flow of air from passages 177, 178 and 179 to the passageway 92 and also to the main passage 88. As the engine starts, the liquid level may be about at passage 174. Under running conditions the level will drop down to cover only the passages 92 and 93.

-Mounted around plunger 152. on the top of the housing 74 is'an L-shaped conductive bracket 180.which hasone leg extending upwardly and apertured. to. receive in supporting association the neck 182 of a non-conductive switch housing 190 (Figure 3). The bracket 180 is held in place by cam member 158 which rests on the prone leg 184. Spring 168 is the hold-down force for this. assembly of parts. The leg 184 mustbe in contact with housing 174 to insure ground contact for switch 190.

Switch 190 is an explosion-proof construction which has at oneend a conductor 192 projectinginto the switch, this connector being adapted to short the ignition system by grounding it to the engine. This is accomplished by a spring-pressed plunger 194 at the other end of the switch which has a small-recessed spiral convolution spring contact 196 which can contact the inner end ofconductor 192, on which is located a connecting wire 198 leading to the ignition circuit. Tab 166, when it moves to its upper position shown in dotted lines, moves the plunger 194 and the contact spring 196 to contact position at the same time that the valve 156 is moved to closed position, thus shorting out the ignition'system.

Thus, each time the manipulatable control unit 158 is shifted-to a valve closing position of valve 156, it also 'shorts'out the ignition system. The switch 190 is preferably connected into the low voltage side of the magneto, that is, the primary side of the transformer circuit. This avoids arcing to a great degree since a very small gapv of about .00 is sufiicient in this primary circuit. If cut out is made in the secondary circuit, a gap of /2" or more is necessary. This positive cut-out switch is also significant when the engine is used on lawn mowers. If no ignition cut-out is available, or even a cut-out which is pressure released by an operator, when weeds or other objects are being removed from a fouled blade rotor, the incidental turning of the rotor may cause the engine to start and injure the operator. 1

A small spring-pressed plunger 206 is shown at the bottom of Figure 3 to permit drainage of the chamber 112; This plunger at the top has a small flange 208 with a sealing washer 210. At the bottom a small head 212 is formed on the plunger 106, and this head passes through a hole in a cup-shaped element 214, it being assembled through a slot 216 in the wall of the cup. The spring 218 seats in the cup around the shaft 206 to hold theas- 'sembled parts in position. Upward pressure on the cup permits gas to drain from the chamber 112 and also the slight depression 220 in housing 102 forms a sediment trap and permits cleaning out of the bowl. This drainage is useful for storage or shipping and also permits prime starting with gasoline when cheaper fuels, such as kerosene, are used to run the engine, as is frequently done in European countries.

In Figures 5 to 10, a control assemblyisshown for the engine and carburetor. Starting at the bottom of Figure 5, the choke valve 82 shown in Figure 4 is illustrated afiixed to a shaft 240 cut away to a flat at its central portion. The upper part of the shaft 240 is slotted .at 242, and this portion passes through a portion. of the housing 74. The shaft is surrounded by a spring 244, one end 246 of which is anchored in a slot 248 in the neck ofa small plastic insert 250 and the other end inslot 242. This insert has a lug projection 251 extending radially therefrom and is provided with a series of three diametrical surface groves 252, 254, 256, which-provide'four stops for the various positions of the control in a 180 .Asmall cross .plate 260 fits in the slot 242 of shaft 240 and co-operates with a projection 262 within a cylindrical plastic housing 264 to provide a lost motion rotating connection between housing 264 and shaft 240 (Figures 7, 8, 9). This plastic housing has a neck portion 266 extending centrally and upward thereof on which is fastened a control knob, 270. Housing 264 also has an outwardly extending arm 272 with a small depending lug 274 which serves to actuate the control element 158.

Circumferentiall-y spaced from arm 272 is another radial projection 276 threaded to receive an adjustment screw 278 which co-operates with a depending tab 280 on a plate 282 mounted around shaft 266. Plate 282 has a spacer neck portion- 283 which improves the stability of the plate. A slotted grove 284 in plate 282 receives the L-end of wire link 62 (Figure 1). On top of plate 282 is another circular plate 286 which rides on ferrule 287 of housing 264 and serves as a spring seat for a spring 288 surrounding the neck shaft 266 and bearing against a washer 289 which rests against the bottom of an indicator plate 290 fixed on the engine. A screw 292 holds the knob 270 on the assembly. Spring 288 serves to hold the various parts in assembly and also to stabilize the action of control knob. The knob can be adaptedfor remote control if desired by flexible cable orgear and rack assembly.

The parts shown in Figure 5 are assembled in Figure 6.

In Figure 8, it will be seen that the bottom of housing 264 has two downwardly projecting lugs 294 which cooperate with the grooves in the element 250. Az stop element 296 is also provided on the body 264 to co-operate with the radial extensions 251 on the element 250. A radial lug 298 on body 264 serves as-a limit stop for part 280.-

The operation of the knob 270 performs directlythree main functions. First of all, when moved to choke position, the housing 264 through lug 262 contacts the cross piece 260 on shaft 240 to move the choke plate 82 to a positon blocking the passage 76 to create a choke condition in the carburetor. In this position the shaft-240 is moved against the return action of spring 244.

When the knob 270 is turned-from choke position in a clockwise direction as viewed in Figure 1, it first reaches a run position in which the choke plate is moved by spring 244 to a non-choke position in passage 76. In this position the actuator lever 272 moves in between arms 164 and 166 of operating element 158.

A further shifting of the control knob 270 in aclockwise direction to the off position shown swings the operating cam lever 158 to the dotted line position shown in Figure 3, causing the arm 166 to contact the switch button 194 to ground out the ignition system of the circuit and also to lower the valve plunger 152 so that the sealing insert 156 closes off the passage 130.

If desired, a return spring 310 can be mounted around control housing 264 anchored at one end on screw 278 and the other end being free to bear against tab 280 to insure return to a position against. adjustment screw 278 when the control shaft is returned from choke position (see Figure 11).

It will be readily seen that when the knob 270 is returned fully in counterclockwise direction it returns to the choke position as originally described and at the same time earns the operating member 158 to a position where valve 156'is open again and the ignition circuit is complete through the switch 190.

In addition to these three direct functions, the'control knob 270 also has other functions in that the plate 282 is connected to link 62 leading to the pivot arm 52 which controls the governor blade 34 throughspring 54. jln the choke position; spring 54 is tensioned to its greatest degree, and thus through the blade 34 and the ring 38'the throttle is in its wide open position.

Moving knob 270 to its run position releases some of the tension on spring 54 and permitsoperation of the fan blades 30' to urge the governor to a further closed position to control the throttle lever 40. The knob 270 can also be moved clockwise to an idle position where the spring 54 is relieved completely permitting the air from the flywheel 30 to shift blade 34 in a clockwise direction, thus forcing throttle lever 40 against stop screw 312, which can be adjusted for any r.p.m. idle speed. Further movement of knob 270 in the clockwise position will be to an off position where the end of link 62 is loosely disposed in slot 284. The governed speed of the engine at the run position may be adjusted in a wide range by moving screw 278, which limits the motion of the tab 280 on plate 282. Also, the action of governor vane 34 is such that in response to rotation'of blades 30 on flywheel F, it tends to tension spring 54 and through control wire 38 move lever 40 in the throttle closing direction. Additional stops can be provided in the run zone if desired.

The knob 270 thus has five functions in that it may control choke position, run position (one or several), idle position, off position of shut-off valve, ofi position of ignition switch. As is usual with these governor controlled engines, when load is applied to the engine,' .the reduced speed will affect the position of blade 34 to increase gas supply to the engine and stabilize the running speed. 1

.It will be noted that to reach the off position the control is always moved through the idle zoneso the engine is slowed down and the throttle closed as the engine stops. Thus, the engine cannot be cut out at high speed. This avoids pulling of excessive amounts of raw gas'into the cylinders as the engine is stopped. Various other adjustments in the running condition of the engine can be accomplished through the usual adjustments provided in the carburetor.

I A carburetor of a somewhat similar description is disclosed in my pending applications Serial No. 365,427,

filed July 1, 1953, now Patent No. 2,813,540, and Serial No. 509,154, filed May 18, 1955. This application is a continuation-in-part of application Serial No. 365,427.

I claim:

1. 'In a carburetor of the type having a float control chamber and a horizontal venturi passage together with an inlet from a fuel supply, a float controlled valve port leading from said supply inlet to said float chamber, a float controlled valve movably mounted in said port, and a second valve member independent of said float controlled valve and mounted in said inlet on said carburetor shiftable from an open position to a closed position blocking said inlet from said float chamber.

2. In a carburetor construction for supplying fuel to an internal combustion engine, a body portion, means connected to the body portion and forming a chamber, a float in the chamber, a bore in the body above the chamber, a fitting in the bore having an inlet port, means in the body providing an inlet passage-adapted to be connected to a fuel supply container positioned above the inlet passage for the gravity flow of fuel, said inlet passage communicating with the port above the same, a valve member in the said fitting acted upon by the float and positioned below the port and arranged to open and close the port in accordance with the position of the float, a plunger positioned in said bore and located above said fitting, a spring around the plunger, a seal member carried by the plunger and adapted to engage the fitting on the inlet side of the inlet port to close said inlet port, the body having a wall at the end of the bore, said plunger extending through said wall and accessible on the outside of the body, and an operating element associated with the accessible end of the plunger movable to shift the plunger against the action of the spring to open said inlet port for :engine operation and movable to release the plunger so that it is acted upon by the spring to close the port for periods of non-use.

3. A device as defined in claim 2 in which the operating element comprises a cam member pivoted on said plunger'and engageable with said body portion wherein movement of said cam moves said plunger in and out of said body to and from a closed position.

4. A device as defined in claim 3 in which means is provided for grounding out an ignition connection for an internal combustion engine, said cam member having a conductive portion to contact said grounding out means when said cam is in closed-valve position.

5. In a carburetor construction for supplying fuel to an internal combustion engine having a fuel chamber and a venturi passage together with an-inlet from a fuel supply, means forming a control port between said chamber and said inlet, valve means on one side of said port to open and close said port in response to fuel in said chamber, a second valve means movably mounted on the other side of said port between said inlet and said port to open and close said port in respective positions of movement, and means mounted on said carburetor independent of said chamber manipulatable to control said second valve means selectively to close said cham-. ber from a fuel supply connected to said inlet.

6. A device as defined in claim 5 in which shiftable means is associated with said carburetor for grounding out an ignition connection for an internal combustion engine, and said selectively manipulatable means is positioned to actuate said grounding out means,

7. A device as defined in claim 6 in which saidmanipua latable member comprises a conductive member pivoted on a portion of said valve member and movable from a a valve-open position out of contact with said grounding out means to a valve closed position in contact with said grounding out means. p

8. A deviceas defined in claim 5 in which said manipu latable means comprises a plunger projectable into said carburetor having one end extending therefrom, a bracket for a grounding-out switch mounted adjacent said plunger, a grounding-out switch on said bracket, resilient means urging said plunger inwardly, and cammeans in contact with said bracket to hold it in place and shiftable to cam said plunger outwardly against the action of said resilient means, said cam means having an extension to contact said grounding-out switch when said valve is in closed position.

9. A carburetor of the type having a venturi passage with a throttle valve in one end and a choke valve in the other, said carburetor having a fuel chamber and a fuellevel control valve for admitting fluid from an inlet of said carburetor to said chamber, a valve control port leading from said inlet to said fuel chamber, a shut-off valve means selectively operable to close said port independently of said control valve, and means on said carburetor operatively connected with said choke valve, said throttle valve and said shut-off valve, wherein said valves may be operated sequentially and selectively by said means. V

10. vA device as defined in claim 9 in which there is associated with the carburetor a switch means for influencing an ignition circuit of an internal combustion en gine and means associated with said shut-off valve and said switch wherein actuation of said shut-off valve to closed position will also actuate said switch to affect an ignition circuit.

11. In a carburetor of the type having a venturi pas.- sage with a throttle control valve at one end and a choke valve at the other, said valves being associated through a governor arm, means for introducing fluid to said carburetor through an inlet, a control port at said inlet, a shut-off valve for opening and closing said controlport, and a control means directly associated with said choke valve and indirectly associated with said throttle valve through saidgovernor arm, said control means being shiftable to open and close said shut-off valve.

12. A device as defined in claim 11 in which the control means comprises a shaft, means at one end of said shaft for manually manipulating said shaft, means at the other endof said shaft connected to said choke valve in a lost motion connection wherein said choke valve is actuated at one extreme position of rotation of'said shaft and is released in the'other position of extreme rotation of said shaft, means for limiting the rotation of said shaft between said extreme positions, means on said shaft operably associated with said shut-off valve toopen and close said valve at aportion of the travel of said shaft adjacent one extreme position, and means on said shaft wherein rotation thereof will influence the biasing effect on a governor arm associated with the throttle valve. 13. In a carburetor of the type having a venturi passage with a throttle control valve at one end and a choke valve at the other, means for introducing fluid to said carburetor through an inlet, a shut-off valve for opening and closing said inlet, an idling passage in said carburetor for furnishing fuel when said throttle valve is closed, a ground-out switch means for an ignition system, a secondary control device for actuating said shut-off valve and said switch means, and a primary control device movable between two extreme positions, means connecting said primary control device to said choke valve to move the choke valve to choke position at one extreme position, means connecting said primary control device to said. throttle valve to influence its position selectively in a zone intermediate the two extreme positions and to close said throttle in a position adjacent the other extreme position wherein said idling passage may function, andmeans operably associating said primary control device and said secondary control device to cause actuation of said secondary control device betweentheintermediate zone and the said other extreme position to'close said shut-off valve and said ground-out switchmeans.

14. A device as defined in claim 13 in which the pri- 'mary control device is a rotatable first shaft, and the means connecting the primary control device and the choke valve comprises a second shaft co-axial with the first shaft and on which the choke valve is mounted, a cross-member on said second shaft, and a housing on'said first shaft over said cross-member having an off-center projection to contact said cross-member to shiftit and the choke valve when said first shaft is rotated to one extreme of its movement.

15. A device as defined in claim 13 in which the means connecting the primary control device and the throttle valve comprises a linkage of the governor type and a connection on the control device for said linkage comprising a plate adjustably associated with said control device to vary the relation with the linkage, and a lost motion connection between said-linkage and said plate.

- 16. A device as defined in claim 13 in which the secondary control device comprises a cam-throw mechanism pivotally mounted on a portion of said shut-off valve to move said valve to open and closed positions, and means projecting from said mechanism which contacts and actuates said switch means when said valve is so moved to closed position.

'17. A device as defined in claim 16 in which'said shutoff valve comprises a port between said inlet and said carburetor and a plunger valve projectable into said carburetor to block said port in one position, said plunger extending from said body, and said cam-throw is pivoted on said plunger and engageable with said carburetor to move said plunger in and out'to and from engagement with said port, and said means associating said primary control deviceand said secondary control device comprises a movable arm engageable with said cam-throw at said other extreme position to shift said cam-throw: tothe shut-cit valve closing position.

18. In a carburetor of the type having a fuel chamber and a venturi passage together'with an inlet from a fuel supply to the chamber, a control valve for liquid level in said chamber, and a second valve movably disposed in'said carburetor to an open position admitting fuel to said control valve and to a closed position blocking fuel for said control valve and said fuel chamber.

' 19. In a carburetor of the type having a fuel chamber and a venturi passage together with an inlet from a fuel supply to the chamber, a control valve for liquid level insaid chamber, and a second valve movably disposed in said carburetor to an open position admitting fuel to said control valve and to a closed position blocking fuel for said control valve and said fuel chamber, said second valve being manually actuatable, and means external of said carburetor for shifting said second valve to open and close positions, said means serving also to hold said second valve in open position.

20. In a carburetor of the type having a fuel chamber and a venturi passage together with an inlet from a fuel supply to the chamber, a control valve for liquid level in said chamber, and a second valve movably disposed in said carburetor to an open position admitting fuel to said control valve and to a closed position blocking fuel for said control valve and said fuel chamber, said second valve being manually actuatable, means external of said carburetor for shifting said second valve to open and'close positions, said means serving also to hold said second valve in open position, means associated with said carburetor for grounding out an ignition connection for an internal combustion engine, said means for actuating said second valve being positioned also to actuate said grounding out means.

21. In a carburetor of the type having a fuel chamber and a venturi passage together with an inlet from a fuel supply to. the chamber, a control valve for liquid level in said chamber, and a second valve movably disposed in said carburetor to an open position admitting fuel to said control valve and to a closed position blocking fuel for said control valve and said fuel chamber, said second valve being manually actuable, means external .of said carburetor for shifting said second valve to open and close positions, said means serving also to hold said second valve in open position, means associated with said carburetor for grounding out an ignition connection for an internal combustion engine, said means for actuating said second valve being positioned also to actuate said grounding out means, said grounding out means comprising an explosion-proof switch, the contacts of which are completely enclosed andhaving a plunger extension projecting from said switch and shiftable to actuate said switch.

22. In a carburetor of the type having a venturi passage with a throttle control valve at one end and a choke valve fat the other, said valves being associated through a governor arm, means for introducing fluid to said carburetor through an inlet, a control port at said inlet, a shut-off valve for opening and closing said control. port, a control means directly associated with said choke valve and indirectly associated with said throttle valve through said governor arm, said control means being shiftable to open and close said shut-off valve, and means interposed between said control means and said governor arm comprising a movable plate resiliently biased for movement in one direction, means for adjustably limiting the movement in said direction, and a lost motion connection between said plate and said governor arm wherein said control means in one position will determine the position of said governor arm and said throttle valve dependent on the adjusted position of said plate, and in the other position will operate said shut-off valve independently of said governor arm.

' No references cited.

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