US1321261A - Percival s - Google Patents

Description

P. S. TICE;

CARBURTER GOVERNING DvlcE.

APPUCATION FILED MAY 10| |917-- RENEWED MAY 1.1919

l 32 1 ,2 6 1 Patented Nov. 11, 1919.'

UmTE'n STATES PATEN onnicn.

PERCIVAL S. TICE, F WASHINGTON, DISTRICT OF COLUMBIA.

CARBURETER-GOVERNING DEVICE.

Specification of Letters Patent.

Application led Hay 1.0, 1917, Serial No. 167,787. Renewed May 1, 1919. Serial No. 294,097.

To all whom t may concern.'

Be it known that I, PnRcrvAL S. TICE, a

Vcitizen of the United States, residing at 715 ings, forming a part thereof.

The purpose of this invention is to provide improved means for governing the air supply to a carbureter for an internal combustion engine. It consists in the elements and features of construction shown and described, as indicated in the claims.

In the drawings, the sole figure is a partly sectional view of a side elevation of a carbureter equipped with this invention, section being made axially with respect to the air inlet and the valve therein.

The drawing shows in conventional or customary form the loat chamber, A, of a carbureter, from which the liquid fuel is discharged through a nozzle, B, into a Venturi tube or constricted throat-way, C, of the suction passage, D, leading to the engine intake (not shown). The suction passage has the air inlet encompassed by a valve seat, 2, facing inwardly, seating the valve, 3. This valve is a hollow or chambered body, most conveniently cylindrical in outline, having its chamber, 3a, opening inwardly toward the suction passage; and it is mounted for guidance in its movement toward and from its seat on a stem, 4, which projects inwardly from a bridge, 5, extended across the air inlet. Rigid with the inner end of this stem, 4, there is a head, 6, which being rigid with the stem is thereby rigid with the valve seat, 'and which is positioned in the open inner end of the chambered valve, and is adapted to operate piston-wise therein in the opening and closing movement of the valve. A spring, 7 reacts between the head and the body of the valve for normally seating the valve by the action of the spring, and resisting its opening by the suction. The stem, 4, is axial hollow, and lthe duct, 4a, therein is continuous from a duct, 5, in the bridge, 5, said bridge, as illustrated, having an axially positioned boss, 5", in which alsothe duct extends, opening radially therefrom for the purpose of controlling the exterior end by a valve member, 8, mounted upon the protruding boss, 5", of said bridge, having an aperture, 9a, for registering with the radially opening end of the duct, and adapted to be rotated on said projection for varying the opening, or closing it entirely. A spring, l1, reacting between a washer, 12, on the end of a stem, 13, which projects from said axial boss, 5b, of the bridge, and a second washer, 14, which bears against the outer end of said valve member, operates to keep the valve snug on its seat, which is tapered to further assist this result. The duct, 4a, in the stem, 4, opens into the piston chamber of the valve, as seen at 4". The head or piston, 6, is constructed for limited leakage, past it from the piston chamber, 3, of the valve, 3, into the suction passage, D, which.

leakage may be effected either by having said piston head slightly loose in the piston chamber, or byv providing it with a small aperture, 15, as shown, or both. Since, as will be understood, the valve is definitely and accurately carried on the stem, 4, and does notV rely upon the piston for its guidance, it isr practicable to make this piston a suiciently loose t to insure limited leakage, and the advantage of obtaining the leakage in this manner is that at the same time the fricthe drawing, the valve 3, operating asthe throttle valve of the carbureter, remains upon its -seat when the engine is. started,

notwithstanding thepartial vacuum created by the engine suction in the passage, D, be-

cause the admission of atmospheric pressure through the ducts, 5a and 4L into the chamber 3a, of the valve, equalizes theppressu'rey 4upon opposite sides of the.. valve. Underv this condition of operation, which: corresponds to very slow rotation ofthe engine crank, as inthe idling of the engine, airl flowing from the .exterior through the continuous ducts 5a, 4a, and aperture, 4", into,` the chamber, 3a, ofthe valve, 3, passes also to av small extent past the piston, virtue of the leakage provided eitheraround the working edgeof the piston `orthroughv the aperture, 15. vThis' leakage being veryE much less than the capacity of the passages by which the atmospheric pressure is admitted to the chamber, 3a, does not eiiect any material reduction of the pressure in the chamber, 3, below atmospheric, and the valve is held seated under the action of the spring. The valve, 8, being adjusted to restrict the air inlet through the ducts, 5a .and 4a, to the chamber, 3a, the pressure in that chamber will be reduced below atmospheric, and such air inlet being reducd suiiciently by the adjustment of the valve, 8, 'the pressure in the chamber, 3, will become lowered by the leakage past the piston, 6, until the excess of atmospheric pressure on the outer face of the vvalve over the reduced pressure within will be suiicient to overcome the resistance of the spring, 7 so that the valve will be opened by the atmospheric pressure to greater or less extent, dependent upon the degree of suction operating in the suction passage, D, and the extent to which the air access through the ducts, 5a et,

is restricted by the adjustment of the valve,

8; and when the chamber, 3a, is completely Shut on" from communication with the atmosphere bythe complete closing of the valve, 8, the pressure within the chamber, 3, will be reduced to that existing in the suction passage, D. The spring, 7, is designed to be of'such stiffness that vunder these conditions the valve, 3, will vbe wide open. It will be understood that one Jfunction of the spring, 7, is to maintain within the suction passage, D, such degree of pressure lower than atmospheric as to be adequate to supe f ply the carbureter with the liquid fuel by theA suction of the engine. When the valve 3, isopen to any extent, the suction in the passage,y D, is reduced,-tliat is, the pressure isV raised,by reason of the entrance of the air past `thevalve, and the leakage past thepiston is reduced. At any given degree of opening of the valve, 8, equilibrium between thefinternal and external pressure on the valve, 3,`-including in the .internal pressure of the resistance of the spring,7,-will be attained at a certain degreeof suction in the passage, D; and the degree of suction being dependent upon the speed of the engine, it follows that the degree of opening of the valve, .8, will rsubstantially determine the engines speed.

, I twill be noticed that the relation of the chambered valve, 3,l to the fixed piston member, V6, is substantially that of the two members oi"A a dash-pot when considered with relation to theaction of the valve under any force tending to open it, and the device does in fact act as a dash-pot, in tending to' steady the action of the valve and prevent it from-fluttering or yielding too sensitively to rapid variations in the suction, which may result from sudden changes of speed of the engine.

The construction shown in this application isa development from a fundamental invention which is ,common to this, application and 'my' pending application No. 127,233, iled Octoberl 23, 1916; and

- this fundamental invention, common to both the applications, is claimed in its broader phases in my said earlier application, and the broad claims 'for that invention are not made in this application.

claim l. `In combination withfa suction passage constructed for affording limited leakage.

past it Jfrom the lpiston chamber 'into the suction passage; a conduit leading from thel outer air into said piston chamber, and

means for controlling the air access to said v conduit.

2. In combination with a suction passage having an air inlet, a valve controlling said inlet opening inwardly; said valve having a piston chamber opening inwardly; a head xed with respect vto the valve seat positioned in the said piston chamber and acting piston-wise therein in the .opening and closing movement of the valve, said head being ,constructed for affording limited Aleakage j past it -from the piston chamber intothe suction passage; a stem xedwith respect to the valve seat, aii'ording 4guidance for the valve and extending into said chamber,

said stem having anair duct leading from the outer air into said chamber, and means for controlling the air access to said air duct.

3. In combination with a suction passage having an air inlet, a valve controlling sald inlet and opening inwardly, said valve having a lpiston chamber opening inwardly;

a head fixed with respect to the valve seat,

positioned in said pistonl chamber and acting piston-wise therein in the opening and closing movement of the jvalve, said head being constructed 'for aiording limited leakage past it from the lpiston chamber into the suction passage; a conduit leading from the outer air into said piston chamber; means for controlling the air access into said chamber, and a spring inthe chamber ive-acting between the valve and said head for resisting the opening movement of -the valve.

4. In combination with a suction passage having an air inlet,.a valve controlling said inlet and opening inwardly; a bridge across said inlet and a stem extending .from said bridge for guidance of the valve in its movement toward and from'its seat; a head fixed with respect to the valve Seat lpositioned in said piston chamber and acting piston-wise therein in said opening and closing movement, said head being constructed forafording limited leakage past it from the piston chamiber into the suction passage; said bridge and stem having ducts leading from the outer airinto the piston chamber of the valve; and eXteriorly-accessible means for controlling air access to said duct.

5. In combination with a suction passage having an air inlet; a spring-seated valve controlling said inlet and opening inwardly, said valve having a piston chamber 'opening inwardly; a head fixed with respect to the valve seat, positioned in said piston chamber and acting piston-wise therein in .the opening and closing movement lof thevalve, the head being constructed for affording limited leakage past it from the piston chamber into the suction passage; a conduit leading from the outer air into said piston chamber, and eXteriorly-accessible means for controlling the air access to said conduit.

In testimony whereof, I have hereunto set my hand at Detroit, Michigan, this 5th

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