US2991986A

US2991986A - Carburetor

Info

Publication number: US2991986A
Application number: US15161A
Authority: US
Inventors: Albert H Winkler
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1960-03-15
Filing date: 1960-03-15
Publication date: 1961-07-11
Anticipated expiration: 1978-07-11

Description

y 1961 A. H. WINKLER 2,991,986

CARBURETOR Filed March 15, 1960 INVENTOR.

ALBERT H. WINKLER AT TORNE! Y United States Patent 2,991,986 CARBURETOR Albert H. Winkler, Elmira, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Mar. 15, 1960, Ser. No. 15,161 5 Claims. (Cl. 261-46) The present invention relates to carburetors for internal combustion engines and more particularly to an enrichment system for supplying an enriched mixture to the engine when the choke is closed or partially closed.

It is an object of the present invention to provide increased fuel flow through the carburetor idle system during starting and warmup operation of the engine.

Other objects and advantages of the present invention will become apparent from the following description taken in connection with the appended drawings where- FIGURE 1 is a sectional view of a carburetor embodying the present invention; and

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

Referring now to the drawings, numeral designates a carburetor, 12 an induction passage, 14 a choke valve, 16 a throttle and 18 a fuel bowl. A main discharge jet 20 discharges fuel from bowl 18 into the throat of venturi 22 formed in induction passage 12.

Idle ports 24 and 26 open into the induction passage on opposite sides of throttle 16 when in closed position and are connected to the fuel bowl 18 by means conduit 28 and idle tube 30. A calibrated air bleed vent 32 connects the upper portion of conduit 28 with the induction passage 12. Vent 32 acts to prevent syphoning from occurring in the idle system and also as an air bleed to emulsify the fuel. A second air bleed passage 34 of larger effective area than vent 32 connects conduit 28 with a port 36 in the side wall of cylinder 38 of the automatic choke designated generally by the numeral 40.

The automatic choke includes a thermostat 42 mounted on the carburetor and engaging choke lever 44 to urge the choke toward closed position when cold. A piston 46 is reciprocably mounted in cylinder 38 and is connected to choke lever 44 by means of rod 48. Cylinder 38 is closed at one end 50 and is connected near its closed end to the induction passage downstream of the throttle by means of conduit 52. The other end 54 of cylinder 38 opens into the induction passage upstream of choke valve 14. A pair of diametrically opposed,

longitudinal grooves

56 and 58 are formed in the side walls of piston 46.

Grooves

56 and 58 open at the end of piston 46 exposed to the open end 54 of cylinder 38 and terminate in spaced relation to the end of piston 46 exposed to the closed end 50 of cylinder 38. A circumferential groove 60 is formed in the piston to connect

grooves

56 and 58. As shown in the solid line position in FIGURE 1, piston 46 is located in cylinder 38 so that port 36 is open when the choke is opened; and, as shown in the dotted line position in FIGURE 1, piston 46 is positioned to close port 36 when the choke is closed.

In operation, thermostat 42 when cold urges the choke valve 14 toward closed position and piston 46 is positioned to closed bleed port 36. Upon starting of the engine, the induction passage pressure below the throttle will be reduced causing the piston 46 to move to the right to partially open the choke valve in opposition to the thermostat. Port 36 is located in the wall of cylinder 38 so as to be closed by the piston 46 until the choke valve has opened a predetermined amount. While idle bleed port 36 is closed, the idle system will discharge an increased amount of fuel through one or more of the "ice idle ports 24 and 26. Upon opening of the choke beyond the predetermined position, the idle bleed port 36 will be opened and the amount of fuel discharged by the idle system will be reduced.

Under some circumstances, the low induction passage pressure communicated to cylinder 38 near its closed end 50 would be suflicient to draw fuel from the idle tube 30, bleed passage 34, between the side walls of piston 46 and cylinder 38 for discharge into the induction passage 12 through conduit 52. This condition would not only be unsatisfactory in supplying an excessively rich mixture but would also cause gum deposits in the cylinder 38 leading to sticking of the piston 46 and improper functioning of the automatic choke 40. The

grooves

56, 58 and 60 are interposed in the piston between the low pressure conduit 52 and the idle bleed port 36 to break any suction that might otherwise occur at the port i.e. should there be leakage between the walls of the piston 46 and cylinder 38 it will be air leakage through the

grooves

56, 58 and 60 rather than a fuel leakage from idle bleed port 36.

While only one embodiment of my invention has been shown and described various changes and arrangements of parts may be made without departing from the spirit of the invention.

I claim:

1. In a carburetor, a fuel bowl, an induction passage, a choke valve and a throttle in said passage, a cylinder having an open end and a closed end, a piston in said cylinder operatively connected to said choke valve, a conduit connecting said cylinder near its closed end with a source of vacuum, a fuel passage connecting said fuel bowl with the induction passage downstream of said throttle, and an air passage connecting said fuel passage to said cylinder intermediate the ends thereof, said piston being adapted to close said air passage when the choke valve is closed and to open said air passage when the choke valve is opened.

2. In a carburetor, a fuel bowl, an induction passage, a choke valve and a throttle in said passage, a cylinder having an open end and a closed end, a piston in said cylinder operatively connected to said choke valve, a conduit connecting said cylinder near its closed end with the induction passage downstream of the throttle, a fuel passage connecting said fuel bowl with the induction passage downstream of said throttle, an air passage connecting said fuel passage to said cylinder intermediate the ends thereof, said piston being adapted to close said air passage when the choke valve is closed and to open said air passage when the choke valve is opened and a second continuously open air passage of smaller effective flow area than said first mentioned air passage connecting said fuel passage with said induction passage.

3. In a carburetor, a fuel bowl, an induction passage, a choke valve and a throttle in said passage, a cylinder having an open end and a closed end, a piston in said cylinder operatively connected to said choke valve, a conduit connecting said cylinder near its closed end with the induction passage downstream of said throttle, a

fuel passage connecting said fuel bowl with the induction passage, and an air passage connecting said fuel p assage to said cylinder intermediate the ends thereof, said piston being adapted to close said air passage when the choke valve is closed and to open said air passage when the choke valve is opened.

4. In a carburetor, a fuel bowl, an induction passage, a choke valve and a throttle in said passage, a cylinder having an open end and a closed end, a piston in said cylinder operatively connected to said choke valve, a conduit connecting said cylinder near its closed end with the induction passage downstream of the throttle, a fuel passage connecting said fuel bowl to said induction passage downstream of said throttle, a port in said cylinder, an air passage connecting said port to said fuel passage, said piston being adapted to close said port when said choke valve is closed and to open said port when the choke valve is opened, and a longitudinal groove formed in'said piston circumferentially spaced from said port, said groove communicating with the open end of said cylinder and terminating in spaced relation to the other end of the piston.

5. In a carburetor, a fuel bowl, an induction passage, a choke valve and a throttle in said passage, a cylinder having an open end and a closed end, a piston in said cylinder operatively connected to said choke valve, a conduit connecting said cylinder near its closed end with the induction passage downstream of the throttle, a fuel passage connecting said fuel bowl to the induction pas sage, a port in said cylinder intermediate the ends thereof, an air passage connecting said port to said fuel passage, said piston being adaptcd to close said port when said choke valve is closed and to open said port when the choke valve is opened, a pair of longitudinal grooves formed in said piston circumferentially spaced from said port, said grooves communicating with the open end of said cylinder and terminating in spaced relation to the other end of the piston and a circumferentially disposed groove in said piston connecting said longitudinal grooves.

References Cited in the file of this patent UNITED STATES PATENTS