US2327675A

US2327675A - Carburetor

Info

Publication number: US2327675A
Application number: US369417A
Authority: US
Inventors: Charles R Snyder
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-12-10
Filing date: 1940-12-10
Publication date: 1943-08-24
Anticipated expiration: 1960-08-24

Description

C. R.' SNYDER CARBURETOR Aug. 24, 1943.

" 2 sheets-sheet 2 Filed Dec. l0, 1940 i CHARpEs R. SNYDER,

-WdW/wza lower or inner end of the tube being threaded to receive a plug 1. This member has its upper end-'1A tapered as at 8 to guide air entering the cham-,-

ber through the tube 4 toward openings 9 formed in the side walls of the tube. Normally, vthese openings are closed by pivoted `gates I and soV held by springs II. The resistance of the springs is of such an extent that the shutters will be maintained in a closed position until the volume of air passing into the mixing chambersr exceeds that capable of passing through a plurality of passages I2 extending through the plug 1. The outlet ends of the passages I2 terminate in restricted nozzles which discharge in the direction Aof impeller blades I3 formed on a plate I4 constituting part of thefuel vaporizing mechanism.

By reason of the restrictions caused by the nozzles, the air entering the tube 4 will build up pressure suflicient to compress the springs Il and permit the shutters Ii) to open to admit air to the mixing chamber. The inclined surfaces at the inner end of the plug are provided with scoop-like baies I5 to insure a proper flow of air into the passages I2. As the air flows through the passages and the nozzles, it will impinge the impeller blades and cause the plate I4 to revolve about the longitudinal axis of the mixingchamber. This rotation of the plate is made possible through the provision of an antifriction bearing I5 to which the plate I4 is secured. The stationary race of the'bearing is secured to a valve body I1 threaded into the open lower end of the plug 1.

The plate i4 is providedwith depending pins I8, the lower ends of which receive and support a vaporizlng disk I9. This disk is disposed in a horizontal plane and rotates with the plate I4 when air is` drawn into the mixing chamber through the nozzles. The center of the disk I9 is in registration withv the discharge end of the gas inlet passage which extends axially through the member I1. A valve stem 20 is rotatably positioned in this passage and has one side flattened as at 23a to register with va reduced slot 2l extending laterally through the Vside of the member I1 to provide for the flow of fuelV to the passage.

When the stem 20 is positioned as illustrated in Figs. 1 and 5, fuel cannot flow through the slot 2l. As the valve is rotated, however, the flat side will be presented to the slot and fuel will be permitted to flow into the passage from which it will be discharged onto the disk I9. Due to the rotation of the disk, this fuel will be discharged laterally in the mixing chamber by centrifugal force, will vaporize and be mixed with the air passing through the chamber. By controlling the rotation of the valve stem, the quantity of fuel permitted to pass through the lslot 2l may also be controlled.

The fuel is conducted to the slot 2| through a tube 22, the inner end of which is connected with a ring 23 between the bearing I5 and a shoulder on the body I1. `The ring23 has an annular recess formed therein to receive the fuel introduced through thel tube V22. The outer end of this tube'communicates directly with thelfuel pump so that fuel will Vbe delivered to the carburetor Y `isjournalecl in the wall of the plug 1. The latter gear receives the splined end of a shaft 25,

the outer portion of which is journaled in a bearing provided in the casing section 2. The extreme outer end of the shaft has a lever 26 secured thereto, the movement of the lever serving to rotate the shaft which movement will be imparted by the gears to the valve stem. To move the lever 26, it is connected by a link 21 with a second lever 23 secured, as at 29, to a shaft 30, the intermediateportion 'of which extends through theinlet tube 4. This shaft is flattened at its central portion to receive the conventional throttle or butterfly valve 3| disposed in the inlet tube and employed to control flow of air into the mixing chamber. The free end of the lever 28 has a perforated block 32 pivotally secured thereto for the vslidable reception of one end of a pusher rod 33. This member has an adjustable stop 34 lsecured thereto and a compression spring 35 surrounds-the rod'between the stop and the block 32'. By this construction, the rodv 33 may be moved Aupward to `impart movement to the lever 28 in the operation of opening the throttle.

If, for any reason, resistance to opening movement is imparted to the throttle, the rod 33 may continue to move upwardly and compressthe spring 35. Movement of thev throttle toward an open position may be resisted by the mechanism designated generally by the numeral 36 in Fig. 1 of the drawings'. This mechanism is connected with the shaft 30 at the opposite side of the carburetor from the lever 28. The mechanism also includes a lever 31, one end of which is secured tothe shaft 3D while the opposite end is pivotally connected with one end of a yoke-shaped link 38. The lower or free end of the link supports a collar 39 slidably positioned on the reduced extension of a piston rod 40.

When movement is imparted'to the lever 31, the link 38 will move the collar upwardly against the lower end of a compression spring 4I disposed between the collar and the inner upper end of a thirnble 42 carried by the upper portion of the rod 40. This portion of the rod is threaded as at 43 to receive an adjusting nut 44 through Y the movement of which theclearance between the lower end of the thimble. and the collar may be varied. When the collar moves upwardly, the springwill transmit this movement to the nut and, in turn,to the rod 4D. .This-Inotionwill cause a piston 45 provided at the lower end of the rod 40 to travel upwardly in an oil cylinder 46. This cylinder is rigidly secured to the carburetor casing. 1 Y

As disclosed in Fig. 3, the piston has a plurality of ports extending therethrough which are normally closed by a spring-,pressed valve 41. When the piston moves upwardly, resistance will be/offered thereto by the oil or other fluid contained within the cylinder and the vacuum pro-` l duced between the bottom of the piston and the cylinder. by-pass line 48 is .connected with the ends of the cylinder so that as the. piston moves longitudinallythereof, the oil will flow thrcugh'the` by-pass to eliminate` the pressure appliedto `the top-of the `ipiston' and the vacuumapplied to the To permit the upward movement, ar

under side. When the piston moves-in `-a downward direction, -the-valve41'will be free to open and oil may flow through the'portsinithepiston without obstruction.

"I'o control the movement of the piston-inthe cylinder, the by-pass linehas a valve 49 positioned therein, this valve-being of the plug type as disclosed in-Fig. 3, although otheretypes of valves may -be Y employed with equal facility. When the valve is closed, the piston willbe restrained against upward'movement. Since the piston is connectedwith theA link 38 through the spring and collar, resistance to movement of the lever3'l will also bev offered'. This resistance will lie-transmitted through theshaft 30 to .the levers 28 and '26 so that `the throttle and-fuel lcontrol -valves will be `stopped in their movement toward-open positions. Normally, the valve 49 will be in an open positionwwhen the engine with which the carburetor is connected is operating under usual conditions. If the accelerator pedal should be suddenly depressed` or an unusual load applied tothe engine, the valve 49 will be .closed to resist movement of the piston. lAt this time, the throttle and fuel valves will Ibe stopped so that an excessive amount offuel will not be introduced. After the engine has increased i-n speed or the load has been relieved, the valve will open and the throttle and fuel valves permitted to resume normal-operation.

The valve 49 is actuated by a lever Eiland a link which transmits movement from a vacuum `operated diaphragm52`to the'lever 59. The diaphragm is carried by a housing 53 disposed in open communication with the interior of the carburetor casing. A coil spring 54 is positioned in the housing between the inner portion and the diaphragm. This spring serves to move the diaphragm outwardly when the vacuum in the casing is reduced. When the spring moves the diaphragm,V the valve plug will be rotated to close the by-pass line and the piston will be checked in its upward movement. If pressureis applied to the accelerator at this time, the shaft'S may rotate and swing the arm 31 upwardly until the collar 39 vengages the lower end of the thimble 42. Upward movement will then be precluded until the diaphragm is drawn inwardly by vacuum'to restore the valvev49 toits open position. The movement of the arm 3l between the stoppage of the piston and the engagement of thev collar 39 with the thi-mble permits the fuel con-V trol valve to move an additional amount whereby the quantity of fuel introduced will be increased after the engine has slowed down because of an increased load.

By adjusting the nut 44, the increased amount of fuel may be varied to prevent the introduction of too much fuel which might stall the engine. Through the admission of this additional amount offuel, the speed of the engine will be increased and when the load is decreased to such an extent that the engine will operate normally, vacuum will be restored and the valve returned to an open position. If the accelerator pedal is still depressed when the valve opens, the energy stored in the spring 35 will cause the lever 28 to move upwardly whereby the throttle and fuel valves will be opened. After the lever 2 .8 has ceased to move, the spring 4| will con-` tinue to move the piston until vthe compression of the spring has been relieved. At this time, the collar 39 will bein engagement with a shoulder on the piston rod and when the pressure on the throttle is released, the piston will be positively moved downwardlyi 'The returnzof thelever 218 mitted bythe shafts25 and the `gearsd .tothe fuel valve to move it .to aclosed position.

The lever. 26 has an extension ,55. for thead.- justable reception of. astop screw 15.6. This Ascrew engage .an abutment .51. lto prevent -movement of the lever 2.6 to a position .wherein .valve f2ilwill be completely closed. ,This provides sufcient Yfuel flow ,to permit the motor to operate atidling speed. The degree of opening maybe varied through the adjustment of stop screw 556,. A second projection .d8V is formed on .the lever 25 to limitthe `degree of opening vmovement of the fuel valve. This projection has an-adjustF able stop screw 5.9.

, Through the provision of` -thetcarburetorxabove described, the throttle valve is located in .ad- Vance of the fuel vaporizing mechanism and is directly connected to the fuel control valve order than when the throttle is opened, the fuel control valve will also be opelld'to increase the flow of fuel. By introducingthe fuel tothe car.- buletor under pressure. a ,quantity in p,rsmortioli to the needs of the motor may beprovided reeerdless of the speed .of operation. Through the limiting device, this quantity ofrfuel may be .Con-

trollecl by e Condition of operation of the eneine so that in the event a leed is applied to the engine to reduce its Speed. the amount-of fuel introduced will not be sufficient to causethe engine to stall. I

When the throttle valve is positioned between the fu'el vaporizing means andthe `engine as in conventional constructions, there is a tendency for the fuel to condense through engagement with the throttle valve. In addition, there is grave danger of ice forming on the throttle due to the lowered temperature ,resulting from rapid vaporization of the fuel. By positioning the throttle valve in advance ofthe fuel vaporizing means whichismadepossible by the construction set forth herein, the outlet leading fromv the car.- buretor mixing chamber is unobstructed and may be decreased in length to such anV extent that .the vaporizing means will be located immediately ad.- jacent to or infthe intakemanifold. When the outlet pSLSsage is thus decreased in length, the casing of the carburetor may be heated to positively prevent any ice formation and provide for a more rapid vapor-ization of fuel.

'To provide for relief forpressureswithin ,the

' mixing Chamber in the event-the engine equipped with the carburetor should backfire, the top sectionA 2 has one or more openings 60 formed therein. These openings are closed by pivoted covers 6l mounted on the outer sides of the section 2. Springs 62 engage the surfaces of the section 2 and the coversV 6l to resiliently hold the latter in normally closed positions. -If the engine should backfire, the increased pressure-within the carburetor `would have no deleterious effect because the covers 6| would-move open to vent the casing.

From the foregoing, it will be Seen that a carburetor has been provided whereby the gas` to air ratio of the fuel mixture introduced tothe engine Will be varied according to the ldemands for power made upon the engine.

What is `claimed is:

`1. In a carburetor of the type having a mixing chamber provided with inlet and outlet passages, fuel vaporizing means in said mixing chamber and means for conducting fuel under pressure to said vaporizing means, a throttle valve disposed in the inlet passage, resilient manually 'operable means `for opening said throttle valve, valve means in said fuel conductingmeans'for controlling the ow of fuel to said vaporizing means, motion transmitting means `connectingl said throttle and fuel valves, means connected with one of said valves for interrupting the movement of said valve toward an open position,1 and means Iconnected with said "movement interrupting means and operative upon a decrease in the .suction created by the engine equipped with the carburetor to render said movement interrupting means operative. l

2. In a carburetor of the type Vhaving a mixing chamber provided with inlet and outlet passages, fuel vaporizing means in said mixingv chamber and means for conducting. fuel under pressure to said vaporizing means, a throttle'valve disposed in the inlet; passage, resilient manually operable means for opening said valve, valve means inV said fuel conducting means for controlling the flow of fuel to said vaporizing means, motion transmitting means connecting said throttle and vfuel valves, means connected with one of said valves for interrupting the movement of said valve toward an open position, a lost motion connection between said movement interrupting means and one of said valves and means connected with said movement interrupting means and operative upon a decrease in the suction created by the engine equipped with the'carburetor to render said movement interrupting means effective, said lost motion connection providing for a slight ad ditional movement of the valve connected therewith after said movement interrupting means becomes operative.

3. In a carburetor of the type having a mixing chamber provided with inlet and outlet passages, fuel vaporizing means in said mixing chamber and means for conducting fuel under pressure to said vaporizing means, a throttle valve disposed in the inlet, passage, resilient manually operable means for opening said valve, valve means in said fuel conducting means for controlling the flow of fuel to said vaporizing means, means for simultaneously moving said valves toward open positions, means rendered operative upon thedecrease of suction produced by the engine equipped with the carburetor to fix the extent of movement of said valves toward open positions, and means between said last-mentioned means and one of said valves to delay the effect of said means on said valve.

4. In a carburetor of the type having a mixing chamber provided with inlet and outlet passages, fuel vaporiaing'means in said mixing chamber and means for conducting fuel under pressure to said vaporizing means, a throttle valve disposed in the inlet passage, valve means in said fuel conducting means for controlling the ow of fuel to said vaporizing means, means fory simultaneously moving said valves toward open positions and means regulated by the suction of the engine for controlling certain operations of said valves, said means having a cylinder for the reception of a quantity of fluid, a piston-movable in said cylinder for displacing the fluid, means for connecting said piston and said valves, the former being movable substantially in unson with the latter, means establishing communication between the ends of said cylinder onopposite sides of said piston, and means operative upon a decrease in suction produced by the engine equipped withthe carburetor to interrupt communication betweenjopposite ends .of said Ycylinder to prevent movementof said pistonand valves. Y y

5. In a carburetor of the type having a mixing chamberprovided withY inlet and outlet pas-` sages, fuel vaporizing means in saidmixing chamber and meansv for conducting fuel` under pressure to said vaporizingmeanaja throttle valve dis,- posed in the inletpassage, valve vmeans -in said fuel conducting means for controlling the flowv of fuel to. said vaporizing means,`means for simultaneously moving said valves toward open positions and means regulated by the suction of the engine for controlling certain operations of said valves, said means having a cylinderefor the reception of a quantity of fluid, a piston movable in said cylinder for displacing the fluid,-alost motion yieldable coupling vconnecting saidpiston and said Valves, the former normally being movable in vunison with the latter, means establishing .communication between the ends ofY said cylinder 'onopposite sides of said vpiston,'and v means operative upon a decrease in suction produced by the engine equipped with the carburetor to interrupt communication between opposite ends of said cylinder to prevent movement vof said piston and valves, said lostmotion connection permitting the valves to move a limited distance after the movement of theipiston is interrupted.

6. Ina carburetor, a casing formed Withan air passageway, the inlet of said passagewaycommunicating with the atmosphere and the outlet with the cylinders of an associated engine, fuel vaporizing means disposed withiny said passageway, a throttle valve arranged in said passageway adjacent to the air inlet end thereof, resilient manually operable means for opening said throttle Valve, means for conducting fuel under pressure to said vaporizing means, valve Ymeans associated with said fuel conductingfmeans forv controlling the flow of fuel to said vaporizing means, motion-transmitting means directly connecting said throttle valve and fuel control valve means, and means controlled byconditons of operation of the engine being served bythe carburetor for automatically limiting the extent of movement of said hrottle valve and fuel control valve means toward open fluid-flow admitting positions. f f

7. In a carburetor, a-casingy formed with an air passageway, the inletof said passageway communicating with the atmosphere and the outlet with the cylinders `of an associated engine, Yfuel vaporizing means disposed within said passage- Way, a throttle valve arranged in said passageway adjacent to the air inlet end thereof, resilient manually operable means foropening saidV throttle valve, means for conducting fuel under pressure to said vaporizing means, valve means associated with said` fuel conducting kmeans for controlling theflow of fuel to said vaporizing means, motion-.transmitting means directly connecting said throttle valve and fuelcontrol valve means, d means connected with, said throttle and fuel control valve means for automatically limiting the extent of movement thereof toward openfluid-,flow admitting positions, said limiting means having a variable stop, and means actuated by vacuum produced in the engine served'r CHARLES asNYDER,