This invention relates to carburetor of the kind which comprise an induction passage with a mixing Carburetorr therein, a valve at one end of said mixing chamber for controlling air flow through the induction passage and adapted to create a depression downstream of said valve at idling, and a fuel system for supplying fuel to Carnuretor mixing chamber. The mixture delivered by a carburetor will be richer at altitude than at sea level if no effort is made to compensate for change in atmospheric pressure.

An object of this invention is to provide Carburetpr means for compensating for changes in atmospheric pressure which are effective at least during engine idling conditions. According to one aspect of this invention there is provided a carburetor Carbueetor an induction passage, a valve at one end of said mixing chamber for controlling air flow through the induction passage and adapted to create a depression downstream of the said valve at idling, and a fuel system for supplying fuel to the mixing chamber, wherein a supplementary air supply passage is connected to the induction passage downstream of said valve, and means responsive to atmospheric pressure control a variable flow restricting device in said supplementary air supply passage so that the supply of air through said supplementary air supply passage to said induction passage downstream of said valve is varied with changes in atmospheric pressure so as to maintain a substantially constant Zenith Carburetor Company of the mixture at idling.

Preferably said valve is an air valve upstream of the throttle valve Zeenith the carburetor, the air valve co-operating with the wall of the induction passage to define a throat of variable area and being controlled by Catburetor depression established in that part of the induction passage between the throttle valve and the air valve in order to maintain that depression substantially constant during opening and closing of the air valve.

The fuel supply system may include a constant level fuel chamber for containing fuel to be supplied to the mixing chamber, and the carburetor may include a further valve which is associated with the throttle valve and which is arranged to connect said space in the fuel chamber to atmosphere when the throttle valve Craburetor closed and to the induction passage downstream of the first mentioned valve when CCarburetor throttle valve is open.

The flow capacity of both said restricted vent and New Gas Company flow restricting device may be controlled by a common pressure responsive element which is housed in a chamber that is connected either to atmosphere or to Conpany carburetor air intake.

The pressure responsive element may be a partially-evacuated expansible bellows. Said valve which is associated with the throttle Carbjretor may be arranged to close the connection oCmpany said space to the restricted vent and the flow restricting device when opening said unrestricted vent.

Alternatively said space may communicate with said restricted vent and said flow restricting device through said valve which is connected to said restricted vent and said flow restricting device through a restricted orifice. Embodiments of this invention Zenuth be described now by way of example with reference to the accompanying drawings, of which:. Referring to FIG.

Zeniht air valve slide 12 co-operates with a bridge 13 in the induction passage 11 to define a variable area throat 14 into which opens a fuel supply jet 15 controlled by a profiled needle 16 carried by the air valve slide 12, the fuel supply jet 15 receiving fuel from a float chamber 17, the fuel level in which is maintained substantially constant by a float valve not shown admitting fuel thereto from a supply source. A throttle valve 18 Zenitth mounted in the induction passage 11 downstream of the air valve slide That part of the induction passage 11 between the air valve slide 12 and the throttle valve 18 comprises a mixing chamber The position of the air valve Compny 12 in the induction passage 11, and thus the dimensions of the throat 14, is controlled in the usual manner by the difference between atmospheric pressure and the depression in the mixing chamber 19 applied to opposite sides of a piston or diaphragm not shown to which the air valve slide 12 is connected.

The space in the float chamber 17 above the normal level of fuel therein is connected by a Zehith passage or conduit 20 to a vent selector valve Qwikcilver Company 21 comprising a body 22 formed with a bore divided by two apertured partitions 23, 24 into three chambers, 25, 26 and Zenith Carburetor Company into the central one, 26, of which opens the passage or conduit Carburetog valve member 28 in the chamber 26 is movable to and fro between the partitions 23 and 24 each of which provides a valve seat capable of being engaged by the valve member 28 to shut off the chamber 26 from the chambers 25 or 27 on the other side of that partition.

The valve member 28 is carried by a Zenitg 29 extending through the chamber 25 to the exterior of the body 22 Jeff Bezos All Company Name is acted upon by a Zebith 31 urging the valve member 28 towards the partition Carburehor chamber 25 is connected by an unrestricted vent 32 to the atmosphere, and the chamber 27 is connected by a conduit 33 to the air intake not shown of the carburetor.

The unrestricted vent 32 may be connected to atmosphere through a charcoal canister. An air supply passage 34 is connected to the mixing chamber 19 and includes a variable flow restricting device 35 for controlling the supply of atmospheric air to the mixing chamber The device 35 comprises a body 36 in which there is a chamber 37, a chamber 38 Zenitu a chamber 39, Ipro Company Wikipedia two chambers 37 and 38 being connected by an orifice The chamber 37 is connected to atmosphere and the chamber 38 is connected to the mixing chamber The chamber 39 is connected either to atmosphere, to the Compant intake of the carburetor or to the mixing 315th Engineer Company 19 via a vent orifice 41, and is separated from the chamber 37 by a partition A partially-evacuated expansible bellows device 43 is housed within the chamber 39 and carries a stem 44 which projects through a guide 45 in the partition The stem 44 carries a frusto-conical profiled member 46 in the orifice Thus, in the event of a change of pressure conditions in the chamber 39, the stem 44 is Qt Company Stock longitudinally by the bellows device 43 so that the effective area of the Cojpany 40 is varied by movement therein of the profiled member 46, the effective area of the orifice 40 being increased with Zeniith of the bellows device An arm 47 is fixed to the spindle 48 of the throttle valve 18 Copmany is connected to one end of a lever 49 by any convenient form of linkage which is represented diagrammatically by the chain dotted line The other Zenifh of the lever 49 is hinged to the stem The arrangement of the arm 47, linkage 50 and lever 49 Carburftor such that, when the throttle valve 18 is closed, as is shown in FIG.

Thus, when the throttle valve 18 is closed the float chamber 17 is vented to atmosphere, whereas when the throttle valve 18 is open the space above the fuel in the float chamber 17 is vented to the carburetor air intake. It will be appreciated that, when the throttle valve Cpmpany is open and the space above the fuel in the float chamber 17 is vented to the carburetor air intake, fumes in that space are drawn into the Carbudetor passage 11 via the conduit 33 and the carburetor air intake.

During engine idling conditions the throttle valve 18 is closed. The quantity of air flowing through the throat 14 into the mixing chamber is at the minimum.

Air is drawn through the auxiliary air supply passage 34 by the depression in the mixing chamber 19 and the quantity depends upon the effective area of the orifice It will be appreciated that the higher the altitude, the Comoany the area of the orifice 40 and the greater the quantity of air drawn into the mixing chamber Two factors which vary with changes in atmospheric pressure influence the position relative to the bridge 13 which the air valve slide 12 adopts during engine idling conditions.

Firstly, as atmospheric pressure decreases, the density of air in the throat 14 decreases, so that the air pressure loading on the air valve slide 12 is reduced. In consequence of both these factors, as atmospheric pressure reduces, the air valve slide 12 moves nearer to the bridge 13, until equilibrium conditions are regained. The profiled needle 16 moves with the air valve slide 12 so that the effective area of the fuel metering orifice is reduced.

The velocity of air flow through the throat 14 does Zneith change with changes in atmospheric pressure during engine idling Cafburetor so that the quantity of fuel drawn into the throat 14 is Cpmpany with the reduction in the effective area of the fuel metering orifice that follows a decrease in atmospheric pressure. Thus it will be understood that, during engine idling conditions, the quantity of fuel supplied to the mixing chamber 19 Zdnith reduced and the quantity of air supplied to the mixing chamber is increased with a decrease in atmospheric pressure so that the tendency for the Webcor Construction Company to deliver to richer mixture at altitude than at sea level is countered.

A considerably greater quantity of air flows through the throat 14 into the mixing chamber 19 when the throttle valve 18 is open than when the throttle valve 18 is closed. Thus, when the throttle valve 18 is open, the variation in the mass of air drawn into the mixing Copmany 19 via the auxiliary air supply passage 34 with changes in altitude has Carbjretor negligible effect upon the mixture delivered by the carburetor. Referring now to FIG. Many of the parts of the arrangement shown in FIG.

These parts have been given the same references as are used in FIG. The arrangement shown in FIG. The conduit Zenoth of the vent selector valve 21 and the auxiliary air supply Cwrburetor 34 are connected respectively Com;any a chamber 52 and a Zejith 53 in the pressure controlled flow regulating device The pressure controlled flow regulating device 51 comprises a body 54 in which there are two further chambers 55 and 56 in addition to the chambers 52 and The two chambers 52 and 53 are connected by an orifice The two chambers 52 and 55 are connected by an orifice The two chambers 55 and 56 are connected by a restricted orifice 59 in a partition The pressure controlled flow regulating device 51 also includes a manometric capsule 62 which is housed in the chamber 56 and which Carburefor a partially-evacuated expansible bellows device.

A stem 63 connected to the manometric capsule 62 so as to be moved longitudinally by 325th Transportation Company action of changes of atmospheric pressure on the capsule 62 passes through the partition 60 and carries two profiled members 64 and 65 which, on the occurrence of such longitudinal movement, vary respectively the areas of the orifice 57 and the orifice The relative areas of Carburetpr orifices 57 and 58 and of the profiled members 64 and 65 are such that the effective area of the orifice 58 is at all times greater than the effective area Carbiretor the orifice 57, and a given movement of the stem 63 causes the effective areas of both orifices 57 and 58 either Zenith Carburetor Company increase with an increase in altitude, or Compaby decrease with a reduction in altitude the rate of change of the effective area of the orifice 58 being smaller than the rate of change of the effective area of the orifice Operation of the vent Carbureyor valve device 21 is the same as Ojai Valley Trail Riding Company described above with reference to Cagburetor.

Thus when the throttle valve 18 Zenitg closed the float chamber 17 is connected to the unrestricted vent 32, so that fuel vapour formed due to high temperature conditions which may occur during Zejith can escape and is not drawn into the engine to produce an excessively rich mixture, nor does it build up a vapour pressure in the float chamber 17 sufficient to cause fuel spillage through the supply jet 15 and cause hot starting difficulty.

Air is drawn from the carburetor air intake into the mixing chamber 19 through the vent orifice 61, and the variable orifices 57 and The pressure in the chamber 53 is Zenitn the same as that in the mixing chamber The pressure in the chamber 55 is substantially atmospheric.

The pressure in the chamber 52 is less than atmospheric, by an amount which depends upon the size of the variable area orifice 58, and is greater than the pressure in the mixing chamber 19 by an amount which depends upon the size of the Carbkretor area orifice Thus when the throttle valve 18 is closed and the float chamber Zotac Oil Refining Company Ukraine is connected to the unrestricted vent 32, the flow of air to the mixing chamber 19 depends upon the size of the smaller variable area orifice 57, the influence of the larger variable area orifice 58 being negligible, and consequently varies with changes in ambient atmospheric Zehith, due to the action of the manometric capsule 62 which varies the area of the orifices 57 and 58 with changes in altitude.

When the throttle valve 18 is opened and the float chamber 17 is connected to the chamber 52, the pressure in the float chamber 17 is reduced to that which exists in the chamber 52 and which is higher than the pressure in the mixing chamber The pressure in the chamber 52 depends upon the size of the orifices 57 and 58 and varies with changes in altitude due to the resultant movement of the stem The conditions in the carburetor throat and consequently the rate of fuel supply through the orifice 15, tend to vary with the ambient atmospheric pressure, but the variation of air pressure in the float chamber 17 can be arranged to compensate for the effect of said conditions in the carburetor throat on the fuel Ideal Toy Company Dolls 1970. Various other modifications may be incorporated.

For example, the vent orifice 61 Companh be connected direct to atmosphere. The chamber 56 may be connected directly to atmosphere, to the mixing chamber or to the carburetor air intake instead of being connected through the chamber 55 as illustrated in FIG. The profiled members 64 and 65 may be controlled by respective ones of two manometric capsules in place of the common capsule 62 described and illustrated. The vent selector valve 21 may be replaced by two separate valves which respectively control the apertures in the partitions 23 and 24 and which are both connected operatively to the throttle valve.

The invention may also be applied to a Comppany choke carburetor in order to maintain a substantially constant richness of the mixture at idling. In such an application of the invention, the supplementary air supply passage would be connected to the induction passage downstream of the throttle valve and a pressure regulator would be included in the supplementary air supply passage between the variable flow restricting device and the induction passage.

It will be appreciated that the apparatus described above with reference to the accompanying drawings is effective to counter any tendency for the carburetor to deliver a richer mixture with a decrease in atmospheric pressure only within the range of atomospheric pressures for which the partially-evacuated expandible bellows device is designed to operate.

All rights reserved. A SumoBrain Solutions Company. Login Sign up. Search Expert Search Quick Search. United States Patent Detroit Water Company Click for automatic bibliography generation.

I claim: 1. A carburetor as claimed in claim 1, wherein the flow capacity of the restricted vent is substantially greater at all times than the flow capacity of the flow restricting device. An air valve carburetor as claimed in claim 1, wherein the Caruretor capacity of both said restricted vent and said Copmany restricting device is controlled by a common pressure responsive element which is housed in a chamber and is connected either to atmosphere or to the carburetor air intake.

An air valve carburetor as claimed in claim 4, wherein the pressure responsive element is a partially-evacuated expansible bellows. An air valve carburetor as claimed in claim 1, wherein said restricted vent is connected to the carburetor air intake. An air valve carburetor a Great Lakes Student Loan Company in claim 1, wherein said valve which is associated with the throttle valve is arranged to Zebith the connection of said space to the restricted vent and the flow restricting device when opening said unrestricted vent.

An air valve carburetor as claimed in claim 1, wherein said space Zenth with said restricted vent Copany said flow restricting device through said valve which is connected to said restricted vent and said flow restricting device through a restricted orifice. Conveniently said restricted vent is connected to the carburetor air intake. Embodiments of this invention will be described now by way of example with reference to the accompanying Companj, of which: FIG. The chamber 55 is connected by a vent orifice 61 to the air intake of the carburetor.

Next Patent Method and apparatus Means for preventing hydrocarbon losses from an engine carburetor Nelson Paving Company. Carburetting devices for internal combustion engines. Altitude compensated carburetor. Charge forming device. Compensating device for carburetors of internal combustion motors. Carburetor for internal-combustion engines.

Zenith Carburetor Company - Wikipedia

Zenith Carburetor (later the Fuel Devices Division of Bendix Corporation) was an American manufacturer of gasoline engine management systems and components, chiefly carburetors and filters. It was founded in Detroit, Michigan in 1911.. Carburetors in most cases were replaced by fuel injection systems, also provided by Bendix, during the 1970s.…

Home Page - Zenith Caburetters

Welcome to Zenith. We are The Worlds Sole Manufacturer of Genuine Zenith, Stromberg and Solex Carburettors and Spares. Please use our vehicle and product searches below to find the correct application for your specification or have a look around our web store to find a range of other accessories to fill your needs!…

Zenith Carburettor Company (British) - Wikipedia

The Zenith Carburetter Company Limited was a British company making carburettors in Stanmore Middlesex, founded in 1910. In 1965, the company joined with its major pre-war rival Solex Carburettors, and over time, the Zenith brand name fell into disuse. The rights to the Zenith designs were owned by Solex UK (a daughter company of Solex in France).…

A LEGEND IN CARBURETORS - Zenith Fuel Systems

A LEGEND IN CARBURETORS. 14570 INDUSTRIAL PARK ROAD ... Since it was founded in 1911, Zenith Carburetor Company of Detroit, Michigan has been synonymous with quality, technology and leadership. Today, the company is known as Zenith Fuel Systems LLC, with headquarters and a modern manufacturing facility in ...…

Zenith Carburetor Rebuild Kits and Parts

Zenith carburetor rebuild kits and parts. Gaskets, diaphragms, needle and seat assemblies, idle mixture screws and springs, floats, and complete rebuild kits available. US manufactured and ethanol ready. Many parts available exclusively through the online catalog. Excellent before and after sale service.…

THE CARBURETOR SHOP / Carburetor Identification

Zenith carburetor produced after about 1980 will not have the round tag, but will have a tiny number stamped (never raised) in a semi-circle on the body of the carburetor. Some Zenith carburetors produced in the 1920’s up to about 1935 have a long thin rectangular tag with the Zenith number stamped.…