US2916271A

US2916271A - Carburetor vent arrangement

Info

Publication number: US2916271A
Application number: US537319A
Authority: US
Inventors: Olson Elmer
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1955-09-29
Filing date: 1955-09-29
Publication date: 1959-12-08
Anticipated expiration: 1976-12-08

Description

E. OLSON CARBURETOR VENT ARRANGEMENT Filed Sept. 29, 1955 Dec. 8, 1959 HIS IN VEN TOR.

HNER 0130" If. Maria A T T URI/i Y United States Patent CARBURETOR VENT ARRANGEMENT Elmer Olson, Rochester, N.Y., assignor to General --"Motors Corporation, Detroit, Mich., a corporation of Delaware This invention pertains to carburetors for internal combustion engines, and particularly to means for vent- :ing a carburetor mixture conduit to atmosphere anterior ,to the closed position of a throttle valve.

Heretofore, it has been proposed to form vent means in the throttle body of a carburetor anterior to the closed position of the throttle valve, by drilling a hole, or holes,

in the throttle body which connect the mixture conduit to atmosphere. Vent means of this type are disclosed in the Weldy Patent 2,690,331, and the vent means permit the fuel vapor which collects in themixture conduit anterior to the closed throttle valve to exhaust by gravity to atmosphere when the engine is not in operation. The incorporation of vent means connecting the mixture conduit to atmosphere anterior to the closed position of a throttle valve greatly facilitates the restarting of a hot engine. vent anterior to the closed position 'of a throttle valve Without, additional machining operations such as are necessary in the aforementioned Weldy patent. Ac-

cordingly, among my objects are the provision of a carburetor including vent means for the mixture conduit, which vent means are located anterior to the closed position of a throttle valve disposed therein; and the further provision of a gasket for insertion between portions of a carburetor mixture conduit having vent means formed therein.

The aforementioned and other objects are accomplished in the present invention'by forming vent means in the gasket between the carburetor fuel bowl body and the throttle body which connect the mixture conduit to atmosphere anterior to the closed position of the throttle valve. While the carburetor disclosed herein is of the four-barrel type having two primary and two secondary induction mixture conduits, this is only exemplary, since the gasket construction could obviously be modified for This invention relates to means for forming a 7*:

use with either single or double barrel carburetors. Spe- I cifically, the gasket of this invention is composed of fibrous material having an irregular shape, and is formed with four substantially circular openings which correspond to the portions of the mixture conduit in the fuel bowl casting and the throttle body casting. The gasket is interposed between the fuel bowl casting and the throttle body casting which are interconnected by a plurality of bolts and forms a seal between the two castingsexcept for the mixture conduit vent means.

Each primary mixture conduit opening in the gasket is formed with a substantially radially extending slot, the inner end of which intersects the mixture conduit and the outer end of which is closed by the peripheral edge of the gasket.- However, a portion of each radially extending slot communicates with atmosphere below the fuel bowl casting and above the throttle body casting. Each secondary mixture conduit opening in the gasket is formed with a substantially tangential slot, the inner end of which intersects the mixture conduit opening and the outer end of which is closed by the gasket periphery.

2,916,271 Patented Dec. 8, 1959 However, as described in conjunction with the primary mixture conduits, the slots connecting with the secondary mixture conduits are exposed to atmosphere between the fuel bowl casting and the throttle bowl casting. The vent slots in the gasket are located anterior to the closed position of the throttle valves which are disposed in the throttle body and permit the exhaust of 'fuel vapor to atmosphere by gravity when operation of the engine is discontinued with the throttle valves in the closed position. 1

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a view, partly in section and partly in elevation, of a carburetor constructed according to this invention.

Fig. 2 is a sectional view taken along line 22 of Fig. 1.

Fig. 3 is a fragmentary sectional view taken along line 33 of Fig. 2.

As pointed out in the aforementioned Weldy patent, it is desirable for several reasons to vent the mixture conduits of a carburetor to atmosphere so that the fuel vapor which collects above the closed throttle valves in the mixture conduits when operation of the engine is discontinued may exhaust to atmosphere. With reference to Fig. 1, a conventional four-barrel carburetor is depicted generally by the numeral 10, the carburetor including an air horn body casting 12 within which an automatic choke valve 14 is mounted, a fuel bowl body casting 16 and a throttle body casting 18. The air horn casting 12 is connected to the top of the fuel bowl casting 16 by a plurality of screw fasteners 20, a suitable gasket 22 being interposed between the body members 12 and 16. Similarly, the throttle body casting 18 is formed with a flange 24 which is connected by screw devices 52 to the lower surface of the fuel bowl member 16, a gasket 26 being interposed between the body members 16 and 18.

The fuel bowl body member 16 has formed therein a pair of primary mixture conduit portions 28 and a pair of secondary mixture conduit portions 30, which in accordance with conventional practice are substantially cylindrical. The throttle body member 18, likewise, has formed therein primary mixture conduit portions 32 and secondary mixture conduit portions 34, which are generally cylindrical, and the conduit portions in both the fuel bowl body 16 and the throttle body 18 constitute the mixture passages, or conduits, of the carburetor. The

conduit portions

28 and 30 in the fuel bowl body 16 are formed with main venturis, not shown, and fuel nozzles so as to form a combustible mixture which is supplied to the engine, not shown, through the mixture conduits as controlled by primary throttle valves 36 and secondary throttle valves 38. The primary throttle valves 36 are mounted on a common shaft 40 rotatably journaled on the throttle body 18, and the secondary throttle valves 38 are attached to a common shaft 42, likewise, rotatably journaled in the throttle body 18.

With particular reference to Figs. 1 and 2, it will be noted that the gasket 26, composed of suitable fibrous materials, is formed with a pair of circular openings 44, which correspond to the

conduit portions

28 and 32 and a second pair of substantially circular openings 46, which correspond to the

conduit portions

30 and 34. Each primary conduit opening 4'4 on the gasket 26 is formed with a substantially radially extending slot 48, the outer end of which is closed by the periphery of the gasket, and the inner end of which intersects the opening 44. The gasket 26 is also formed with a pair of tangentially extending slots 50, the outer ends of which are closed by the gasket periphery, and the inner ends of which intersect gasket openings 46. The

slots

48 and 50 constitute the vent means formed in the gasket 26, which slots are anterior to the

throttle valves

36 and 38 when the throttle valves are in the closed position, as depicted in Fig. 1. As seen in Fig. 3, the upper surface of the gasket 26 engages the lower surface of the fuel bowl casting 16, While the main section of the throttle body casting 18 is spaced therefrom. Accordingly, the outer portion of the slot 50 communicates with atmosphere and forms a downwardly opening passage whereby fuel vapor collecting above the closed throttle valves in the mixture conduit can exhaust by gravity to atmosphere. The outer portions of the slots 48, which communicate with the primary mixture conduits, are connected to atmosphere in the manner identical to that depicted in Fig. 3. Accordingly,

when operation of the internal combustion engine is discontinued with the throttle valves in the closed position, any fuel vapor which collects anterior to the throttle valves will flow by gravity through the vent means 48 and 50 in the gasket 26 to atmosphere.

From the foregoing it is readily apparent that the present invention provides simple and economical means for venting the mixture conduits of a carburetor anterior to the closed position of throttle valves disposed therein when the engine is not in operation. By forming the vent means in the gasket between the fuel bowl casting and the throttle body casting, the necessity of additional machining operations being performed on the carburetor is eliminated.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A carburetor for an internal combustion engine including, a mixture conduit, a first body member having a portion of the mixture conduit therein, a second body member having a portion of the mixture conduit therein, a gasket interposed between said members having an opening corresponding with the mixture conduit portions in said members, means interconnecting said members, a throttle valve in the mixture conduit portion of the second body member adapted normally to close the mixture conduit when the engine is not in operation, and vent means formed in said gasket anterior to the throttle valve when closed connecting said mixture conduit to atmosphere to permit the exhaust of fuel vapor after operation of the engine is discontinued.

2. A carburetor for an internal combustion engine including, a mixture conduit, a first body member having a portion of the mixture conduit therein, a second body member having a portion of the mixture conduit therein, a gasket interposed between said members having an opening corresponding with the mixture conduit portions in said members, means interconnecting said members, a throttle valve in the mixture conduit portion of the second body member adapted normally to close the mixture con duit when the engine is not in operation, and a slot in 4 said gasket anterior to the throttle valve when closed intersecting said opening and extending outwardly therefrom to connect said mixture conduit to atmosphere and permit the exhaust of fuel vapor after operation of the engine is discontinued.

3. A carburetor for an internal combustion engine including, a mixture conduit, a first body member having a portion of the mixture conduit therein, a second body member having a portion of the mixture conduit therein, a gasket interposed between said members having an opening corresponding with the mixture conduit portions in said members, means interconnecting said members, a throttle valve in the mixture conduit portion of the second body member adapted normally to close the mixture conduit when the engine is not in operation, said gasket opening being circular, and a slot in said gasket anterior to the throttle valve when closed intersecting said circular opening and extending radially outward therefrom to connect said mixture conduit to atmosphere and permit the exhaust :of fuel vapor after operation of the engine is discontinued.

4. A carburetor for an internal combustion engine including, a mixture conduit, a first body member having a portion of the mixture conduit therein, a second body member having a portion of the mixture conduit therein, a gasket interposed between. said members having an opening corresponding with the mixture conduit portions in said members, means interconnecting said members, a throttle valvein the mixture conduit portion of the second body member adapted normally to close the mixture conduit when the engine is not in operation, said gasket opening being circular, and a slot formed in said gasket anterior to the throttle valve when closed intersecting said circular opening and extending tangentially outwardly therefrom to'connect said mixture conduit to atmosphere and permit the exhaust of fuel vapor after the operation of the engine is discontinued.

5. In a carburetor having a mixture conduit with a throttle valve therein, a gasket positioned between portions of the mixture conduit comprising a one-piece member having an opening corresponding to said conduit and vent means formed in said gasket anterior to the throttle valve when closed connecting said mixture conduit to atmosphere.

6. In a carburetor having a mixture conduit with a throttle valve therein, a gasket positioned between portions of the mixture conduit comprising a one-piece member having an opening corresponding to said conduit and a slot anterior to the throttle valve when closed intersecting said opening and extending outwardly therefrom to vent said conduit to atmosphere.

References Cited in theifile of this patent UNITED STATES PATENTS 1,767,664 Geiger June 24, 1930 2,186,480 'Ensign Jan. 9, 1940 2,683,444 Miller July l3, 1954 2,684,058 Boyce July 20, 1954