US2249992A - Fuel supply chamber - Google Patents

Description

July 22, 1941. s. M. UDALE FUEL SUPPLY CHAMBER Filed June 17. 1939 2 Sheets-Sheet 1 INVENIOR.

s. M. UDALE 2,249,992

FUEL SUPPLY CHAMBER July 22, 1941.

2 Sheets-Sheet 2 Filed June 17. 1939 diaphragm chamber 4 l Patented UNITED STATES PATENT OFFICE runnsurrnrcnamnnn Stanley M4 none, Detroit, Mich, auignor to GcorgeMHolleyandEarlHolley- V Application 1 11, 1939, Serial No. 279,643 1 Claim- .(ci. 261-72) v i In the ordinary float chamber of a carburetor,

the gases are automatically removed, either by v p the provision of a passage leading from the space above the level of the liquid in'the mixture out let, or of a passage leading to the air entrance. When the fuel is supplied in a diaphragm chamber, all the liquid which passes into the diaphragm chamber must pass out, together with any vapor entrained with the liquid. As the liquid enters thediaphragm chamber, there is a drop in pressure of approximately seven pounds per square inch. This drop in pressure releases small quantities of vapor which may accumulate and cause irregular running. In the applicants construction, this vapor is automatically removed at all times and the vapor is removed independently of the discharge of the liquid'from the chamber. By this means, the metering characteristics of the carburetor are not interfered with shown in the Patent 2.088,464, issued to Chandler and Kittler.

In the drawings:

Figure 1 illustrates diagrammatically the in vention.

Figure 2 shows the detail of the actual construction used.

Figure v3 shows a plan view on the plane 3-3 of Figure 2.

In Figure 1, in the air entrance I is located a bridge II in which slides a needle valve l2, which controls the discharge of the fuel from the This needle valve I2 is operated by a lever I3 which carries a roller H which engages with the cam l5 keyed to a shaft I 6.

Three gears II, It and I9 intermesh with each other. The gear I1 is mounted on the shaft It; the gear l8 ismounted on the throttle 2|, and the gear I9 is mounted on the throttle 20. These two throttles 20 and 2| approach and recede from the bridge 22 which is streamlined. The opening between the bridge 22 and the throttles 20, 2| thus constitute variable venturi passages.

The fuel controlled by the needle valve [2 discharges through the openings 23, 24 into the air is supplied from the annular passage 28 which communicates with the air entrance ll.

throat of the venturls and discharges on the engine side of the throat of the vcnturis formed between the throttle valves 2!, 2| and the bridge 22. The fuel flows past the restriction II and down the passage 25. V This fuel is mixed with a small quantity of air drawn through the opening 28, and-when the throttles are closed (during the time that the engine is idling) by another small quantity otair' admitted through the opening 21 in the center of the needle valve II. This through an opening 2|. The fuel, which is metered between the restriction II and the needle l2, flow through the passage 4. and is obtained from the lower part-of the diaphragm ll through the tube 48. The diaphragm chamber ll isformed by the two diaphragms 42 and 43 held together by thespring 44. These diaphragms control the needle valves 88, N which are pivoted at 6|.- 62 and control the'fuel entrance from the passage 40. a

The fuel is supplied to the fuel chamber ll under a substantial pressure, but the leverage is such and the diaphragms are so large, and the needle valves N, I! are so small, that the presknown airplane carburetor. The means for the removal of the vapor are as follows! A float 5| pivoted at 52 is located in the upper part of the diaphragm chamber 4| and controls a valve 53 which closes the entrance to the horizontal pas,- sage 54 which terminates in the passage IS in the throat of the variable ventur'i formed between the throttles 2. and the bridge 22.

Operation When the engine is running, vapor accumulates in the upper part of the diaphragm chamber 4| and displaces a certain quantity of liquid. The float 5| descends and in doing so, opens the valve 53. The upper part of the chamberj ll is then subjected to the suction in the throat of the variable venturi. Before any liquid can flow through the passage 54 the float 5| rises and closes the needle-valve 53. The level of fuel in the chamber 41 is thus maintained at the level shown by the broken lines through the center of the float 5|.

In Figures 2 and 3, similar numbers refer to similar parts. For example, the diaphragm 42 operates the lever pivoted at 62, the lever pivoted at 6| being operated by the diaphragm 43. Instead of a needle valve, ball valves 63, N are used. The float ii is located in a chamber on the side of the main body of the carburetor and the needle II is located centrally of the float ii. The vapor is drawn through a pipe 54 to an outlet 55 located in the mixture outlet rather than in the throat of the variable venturi. As the float is not located in the highest part of the diaphragm chamber, it is necessary to provide a passage so that the vapor is drawn from thehighest point in the diaphragm chamber. I

What I claim is:

In combination with a carburetor having a 20 mixing chamber, a throttle valve, a mixture outlet and a normally closed fuel supply chamber controlled by a movable wall, a fuel mechanism adapted to limit the head of fuel in said chamber, a fuel discharge passage having an entrance located substantially at the center of said supply chamber, a vapor outlet leading out of the upper portion of said chamber, both of said pas-

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