US1585741A - Carburetor - Google Patents

Description

May 25 1926.

W. 0. TH EWES CARBURETOR Filed April 26, 1922 2 Sheets-Sheet 1 mn um wmLnAM O.THEWE51NVENTOR.

HIS ATTORNEYS May 25,1926. 1,585,741

W. O. THEWES CARBURETOH Filed April 26, 1922 2 Sheets-Sheet 2 WlLLlAM O. THEWES INVENTOR.

f7 -10 j ms ATTORNEY'S BY fin/541 Patented May 25, 1926 UNITED STATES PATENT @FFEQ E.

WILLIAM 0. 'rnnwns, oriti'neitvintn, OHIO, assislvon 'ro THE R. a s. VALVE cor/r- PANY, or ELYRIA, OHIO, A conro'n'a'rron or care.

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Application filed Api-n 26, 1922. Serial No. 556,593.

This invention relates to carburetors. One of the objects of my invention isto provide a simple, reliable and inexpensive construction, which involves to agreat extent an improved construction of throttle valves.

Another object of my invention is to use the throttle valve as an elementoi the auxiliary venturi and to provide such a construction that by varying the throttle valve, the flow of the "fuel through the'auXili-ary duct is controlled.

Another object of my invention is to provide throttle valves ofsuch construction that the act of operating the throttle valve ,momentarily throttles the initial onru'sh of air, in order to produce-a rich mixture just at the moment of increasing speed.

Another object of myinventionistoprovide other details of improvement tending to increase the eliiciencyand serviceability of a carburetor of the'above character.

To accomplish the foregoing and other useful ends, my invention-comprises means hereinafter more fully set forth" and claimed.

Referring to the accompanying drawings Fig. 1 is a vertical section of my carburetor.

Fig. 2 isa vertical section at'right angles to the planeofFig. 1.

Fig. 3 is a section on line 33, Fig. 1.

Fig. 4 shows the valve as seenin Fig. 2 in closed position Fig. 5 showsthe same valve .partly' closed.

Fig. 6 is an end elevation of the valve shown at the left, Fig. 4 or shown in the lower half Fig.3.

Fig. 7 is an end elevationa'l vie'wot oneot' the valve members.

Fig. 8 is'a si'devi'ew of the valve Fig; 6.

Fig. 9 is aperspective"viewof-one of the throttle valve members.

Fig. 10 is afragmentary side" elevation of the carburetorshowing the fastening member tor'the discs.

Referring more in detail tothe drawings, it will be seen thatthc carburetor is formed around a main'irame 2. Through the carburetor frame there is a main air passage. The intake terminal 3 of this passage is shown atthe right Fig. 3. Just'beyohd the orifice of the terminal 3 is located'thechoke valve 4t operable "by the lever arm 6, and mounted on the stem 5, which projects through the tubular sides or" the terminal 3. The main air stream after passing the choke valve, divides to the right and left, as indicated at 8 and 7, Fig. 2. The air from the chambers 7 and 8 passes into the center chamber 9, Fig. 2 by way of the windows 10 and 11. cated the throttle valve which is composed of two sections, 12 and 13, shown in detail in Fig. 9. It will be seen that the valve 12, Fig. 3 is provided with bearing stems 16 and 17, whereas the valve 13 is provided with a bearing stem 18 in the rear and a bearing stem 19 in the front to which the operating lever 20 is attached. As shown, the stems 16 and 19 have their hearings in the wall 15, whereas the stems 17 and 18 have their bearings in the wall 14. In order to facilitate the removal of the valves 12 and 13, the sections21 and 22 in the wall 15 are removable discs. Att-he point ofcontact, that'is, along the line 23 the discs 21 and 22 have a flat section so as to prevent th'eir turning while in position in the wall 15. lVhcn the valves 12 and 13 are withdrawn to the right Fig. 3, the discs 21 and 22"co'me out with-thevalves. In order to hold these discs in position, I provide a screw 2 1, Fig. 1, which is screwed in the wall 15 and near enough to the discs 21and 22 so that the head of the screw 2% serves to hold the discs in position. As shownin'the drawings the valve 12 is provided witha series of gear teeth 25, and the; Valve 13 with a series oi gear teeth'26, which mesh as shown in Fig. 3 whereby the valve may be rotated in opposite directions so that the'wings 27 and 23, Fig. 5 either approach each other and come in contact as' shown in Fig. 4 when the throttle valve is closed or separate as inclicated in Fig. 2 when the throttle is wide open. I'have made these valves, as willbe se'en byreferring tofthe various drawings with, the under surfaces 29 and 30 substantially plain about three-fourths of the way. The left side ot-the valve 12, Fig. 4.- and the right side'ot' the valve 13, I have constructed each with a heel 31 and 32 projecting downwardly. Theseheels serve as shut oils for the apertures 10 and 11, when the throttle valve approaches a closed position, see 4 and 5. The valve members are termed in their major part as cylinders and in one side thereof intermediate the ends is provided a Within. this center chamber is 10-,

semi-circular recess 7 2 which extends transversely of the axis thereof and at its central portion substantially tangent to the axis. The sides 73 of one end of the recess 72 curve annularly forming one side of the wings 27 and 28, the end of which wings is straight and parallel with the axis of the valve members. These recesses are adapted to cooperate to provide a variable passageway 38 for the atomized fuel. li hen the recesses are associated to arovide a passageway, it will be seen that such passageway is smaller at the bottom or inlet end than at the upper or outlet end. lVhen in wide open position the passage forms a continuation of the Venturi tube, but when in any position less than wide open the lower end of the passage formed is of smaller diameter than the adjacent end of the Venturi tube, and increasing in area toward the upper or outlet end. T he outlet euu the passage 33, of course, gets la the inlet or lower end thereof is made smaller. It will be seen that the grooves in this manner provide a passageway which acts as venturi, which serves to assist in further atomizing the mixture passing thcrethrough from the mixing chamber.

lVith the construction of the valves shown when the throttle valve is moved cm the closed position shown in Fig. 4 to the position in 5, or to the position shown in Fig. 2, the rear surfaces 29 and 30 of the valves 12 and 13 operate to choke back the air that otherwise would not be impeded in its flow through the windows 10 and 11 up toward the outlet 35, which connects with the manifold. This choking effect on the air has a tendency to increase and make more positive the supply of fuel from the venturi 36 into the central or mixing chamher 9, as will presently more fully appear.

Referring to Figs. 1 and 2, it will be seen that I provide a tube 37, extending down from the partition plate 38, which extends across the carburetor underneath the mixing chamber 9 and the passages '1' and 8. Set in this tubular projection 37, is the Venturi tube 36. This Venturi tube has an orifice 39 that projects into the mixing chamber 9. This orifice is the terminal of a passage 40, which extends to the bottom of the Venturi tube and which terminates in a chamber 41. A flue 42 connects the intake 3 with the chamber 41 through a series of openings 43. Therefore when the choke valve is open, air passes from the intake down through the flue 42 to the chamber 41, thence up through the passagewa 40, and through the orifice 39 to the mixing chamber. Set in the lower end of the Venturi tube I have a nozzle 44 which has a ductpassage 45. A calibrated plug 46 has a duct passage 4 which connects with the duct passage 45 and controls the maximum amount of fuel which can be fed through the carburetor. Surrounding the tubular section 37 of the frame I have a float chamber 48. The arrangement is such that the head of the screw 46 which is located in the chamber 48 is below the surface of the fuel, consequently fuel is supplied to the duct 45 in the nozzle 44, through the duct 47 in the screw 4 1. The air passing upward in the channel at), and the fuel passing out of the nozzle intermingle while passing through the enturi tube into the mixing chamber 9 where atomization is completed. The mixed fuel and air of course pass from the mixing chamber through the throttle valve up through the outlet terminal 35, into the intake manifold. It is through this mechanism that the main fuel supply reaches the engine. This of course is while the throttle valve is open. As an idling device near the head of the screw 46, Fig. 1 I provide a cross duct 53, which crosses the duct 4?. Along the walls of the frame 2 I provide a fuel duct 54-, the lower end of which coincides with the duct 53 in the screw 46. This duct 54 terminates at its upper end in the orifice 55, which orifice opens into the main air passage near the point where the wings 27 and 28 of the throttle valve come together as the throttle valve is closing. See Figs. 4 and 5. There is a restricted opening 56 through the valve wings at a point near the orifice 55. The cut away portions in the wings cooperate to provide a restricted passageway 56 through which fuel from the opening 55 can be directed into the engine for idling purposes, when the throttle valve is closed.

As indicated, the flow of air from the auxiliary air chamber into the mixing chamber through openings 10 and 11 may be controlled by the heels 31 and 32 of the valve members passing over the openings 10 and 11 when the valve members are rotated.

As the valve members are rotated from closed to open throttle position, the openings are gradually uncovered by the heels 31 and 32 admitting a greater quantity of air to the mixing chamber. Simultaneously- :ith this action, the opening from the mixing cham ber to the outlet is increased which serves to increase the supply of fuel into the mixing chamber at a time when ordinarily the mixture becomes lean.

I also find that by the use of the particu lar construction of the undersides of the valves 12 and 13, Figs. 4 and 5 I get a better mixing action in the mixing chamber, resulting in the economy of fuel and in increased efiiciency of the engine. The faces 29 and 30 direct the air from the windows downwardly into the mixing chamber 9 in all relations except when the wings 27 and 28 meet to close the passageway. In this mannerthe air is directed into the chamber in a reverse direction to that in which the Si Cl fuel is moving causing a turbulence in the mixing chamber Which greatly assists the atomization.

Passages 70 are provided through the wall of the Venturi tube extending into the mixing chamber to permit some of the fuel and air passing through the tube to enter the chamber beneath the main outlet into the chamber, thereby causing atomization at the sides and bottom of the chamber.

Having thus described in detail the construction of my invention, what I claim as new is:

1. In a carburetor, a fuel chamber, a Venturi tube, an air inlet leading to said Venturi tube, said Venturi tube discharging into a mixing chamber, said mixing chamber having oppositely disposed openings in its Walls, an outlet leading from said mixing chamher, an auxiliary air inlet communicating with the openings in the walls of said mixing chamber, means for feeding fuel from said fuel chamber into said mixing chamber through said Venturi tube, and a pair of rotatable throttle Valve members arranged between the air openings in said mixing chamber and said outlet, and having cooperating recesses to provide a constricted passage between said mixing chamber and the outlet passage and each having a heel to control the air passing into said mixing chamber from said openings, the size of the passage and the amount of air passing into said mixing chamber being proportionately governed by the rotation of said valve members.

2. In a carburetor, a fuel chamber, a Ventnri tube, an air inlet leading to said Venturi tube, said Venturi tube discharging into a mixing chamber, said mixing chamber having oppositely disposed openings in its walls, an outlet leading from said mixing chamber, an auxiliary air inlet communicating with the openings in the walls of said mixing chamber, means for feeding fuel from said fuel chamber into said mixing chamber through said Venturi tube, a pair of rotatable throttle valve members arranged to control the air passages through said mixing chamber and the outlet passage, said members having cooperating'grooves in one side to provide a passage into said outlet When mated and having recesses arranged to deflect air from the openings in said mixing chamber downwardly in said chamber.

In witness whereof I have hereunto set my hand, this 17th day of April, 1922.

WILLIAM O. THEIVES.

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