US2225943A

US2225943A - Carburetor choke control device

Info

Publication number: US2225943A
Application number: US292869A
Authority: US
Inventors: Schweiss Joseph
Original assignee: Carter Carburetor Corp
Current assignee: Carter Carburetor Corp
Priority date: 1939-08-31
Filing date: 1939-08-31
Publication date: 1940-12-24
Anticipated expiration: 1957-12-24

Description

.Dec. 24, 1940. J. SCHWEISS CARBURE'I'OR CHOKE CONTROL DEVICE Filed Aug. 51, 1939 INVENTOR JOSEPH ScHwE|ss ATTORNEY Patented Dec. 24, 1940 PATENT OFFICE caanmm'roa cnoxr: CONTROL DEVICE Joseph Schweiss, St. Louis, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application August 31, 1939, Serial No. 292,869

7 Claims.

This invention-relates to choke control devices for internal combustion engine carburetors and more particularly to devices for conveniently opening the choke valve against the resistance 6 of automatic choke mechanism. These devices are commonly called unloaders.

With the object in mind of preventing the inexperienced operator from inadvertently operating the unloading mechanism simultaneously 10' with the starting motor, a mis-operation which frequently occurs in arrangements having both starting switch and unloading device interconnected with the throttle, I have provided mechanism which will perform the unloading 15 function only after a period of cranking suflicient to start an engine under normal starting conditions.

It is a further object of this invention to provide an "unloading mechanism actuated by an 20 electro-magnet, the control of which may be either independent of or dependent upon the throttle valve position.

Other objects and advantages will appear in the following description and accompanying 25 drawing referring to which Fig. 1 is a somewhat diagrammatic representation of a carburetor showing one form of my invention. Shown diagrammatically therewith is a starting motor circuit and source of electrical energy.

30 Numeral I generally indicates a conventional downdraft carburetor having an air inlet 2 and a discharge outlet 3. For control of the air inlet an unbalance plate-type choke valve 4 rigidly attached to a rotatable shaft 5 is provided. Shaft 35 5 extends outwardly from both sides of the carburetor and on the far side extends into the automatic choke mechanism housing 6. The automatic choke mechanism includes the usual thermoresponsive element 1 which yieldably positions 40 the choke valve in accordance with the temperature in a manner described in the patent to I. E. Coffey, #2,085,351. The discharge outlet 3 is controlled by a plate-type throttle valve 8 rigidly attached to the rotatable shaft 9. Rigidly attached 45 to the near end of choke shaft 5 is a disc-like member l having a radial projection ll. Adjacent member ID and loosely mounted for rotation on shaft is a lever I2 pivotally attached at one end to the armature l3 of an electro-mag- 50 net 14. At its opposite end lever l2 carries a pin l5 adapted to abut projection I I and thereby rotate member ID and consequently the choke valve toward an open position as armature l3 descends.

55 Rigidly attached to the near end of throttle shaft 9 is an operating lever 20 having a perforation at its outer end for attachment of a rod 2| for remote manual control. A: spring 22 normally urges the throttle valve tOVH'd a closed position. The cam surface 23 on lever 20 is pro- 5 vided to close switch 24 as the throttle is moved toward an open position. In the modification shown, electro-magnet I4 is connected with a starting motor relay switch l5 in the circuit I6 through parallel circuit l6a. The circuit for starting motor I1 is indicated at It. Electrical energy is supplied by storage battery l9. Two switches are indicated in the starting relay circuit l6, namely, a suction operated switch 25 and the aforementioned throttle switch 24. A good l5 form of starting device for use in the present invention and which includes an additional switch in the relay circuit controlled by generator out-- put is shown and described in a patent to I. E. Coiley No. 2,174,313.

To provide a predetermined delay of the functioning of the unloader and thereby permit sufflcient cranking with closed choke to start an engine under normal conditions I have provided a U-shaped heat responsive bi-metallic element 26 series connected in the circuit I 6. A resistance coil 21 in the ground lead from element 28 has been provided for balancing. It will be understood that element 26 is so proportioned as to respond to the heat generated by the flow there- 30 through to spread and connect parallel circuit Ilia to circuit after a predetermined interval during which circuit I6 is closed.

The operation of the device is as follows:

Upon starting a cold engine'the choke valve 4 will be yieldably held in the position shown by heat responsive element 1. As the throttle lever is rotated clockwise to any position beyond that necessary to close switch 24, current will flow through circuit I5 thereby closing starting motor 40 relay l5 to crank the engine. After the period required for element 28 to respond sufliciently to connect parallel circuit I61; and, if within this interval the engine has not been successfully started, electro-magnet [4 will be energized and will open choke valve 4 in a manner described. If, however, the engine has been successfully started within the interval, suction operated switch 25 will open to break the circuit It at that point and remain open during operation of the engine. As the engine warms up the choke valve is free to rotate counterclockwise in an opening direction independent of lever I2. I do not wish to be limited to the detailed description and structure shown, the use of all modifications within the scope of the appended claims is contemplated.

I claim:

1. In combination, a carburetor having a choke valve, a throttle valve, mechanism for yieldably urging said choke valve toward a closed position, an electro-magnet for moving, said choke valve toward an open position against the resistance of said mechanism, an electrical circuit for said electro-magnet, and means coacting with said throttle valve for opening and closing said electrical circuit.

2. In combination, a carburetor having a choke valve, a throttle valve, mechanism for yieldably urging said choke valve toward a closed position, an electro-magnet for moving said choke valve toward an open position against the resistance of said mechanism, an electrical circuit ior'said electro-magnet, a switch in said circuit arranged to coact with said throttle valve, and a second switch in said circuit responsive to heat.

3. In combination, an internal combustion engine, a carburetor having a-choke valve, an automatic choking device'ior yieldably urging said choke valve toward a closed position, an engine starting circuit, a normally disconnected branch of said circuit, an electrically operated device in said branch for moving said choke valve toward an open position against the resistance of said choking device, and a delayed action switch device, responsive to the flow of electrical current through said starting circuit for connecting said branch thereto.

4. In combination, a carburetor having a choke valve, a throttle valve, automatic choke mechanism constructed and arranged to yieldably urge said choke valve toward a closed position, a starting motor control circuit, a normally disconnected branch of said circuit, a throttle actuated switch in said starting motor control circuit, an electro-magnet in said branch for moving said choke valve toward an open position against the resistance of said automatic choke mechanism, and a heat responsive element in said starting motor control circuit arranged to connect thereto said branch circuit after a predetermined interval in which said starting motor control circuit is closed.

5. In combination, a carburetor having a choke valve, an automatic choking device for urging said choke valve toward a closed position, and a manually controlled unloading device comprising an electro-magnet constructed and arranged to move said choke valve toward an open position against the resistance of said automatic choking device, an energizing circuit for said electro-magnet,- a manually operated control switch in said circuit, and adelayed action switch device capable of connecting said electro-magnet into said circuit after a predetermined interval during which said manual switch'is closed.

6. In combination, an internal combustion engine, an engine starting circuit, a carburetor having a choke valve, automatic mechanism for moving said choke valve toward a closed position, an electro-magnet in said circuit constructed and arranged to move said choke valve toward an open position against the resistance of said automatic mechanism under certain conditions, a manual control switch in said circuit, and automatic means functioning to maintain a broken starting circuit during operation of the engine.

'7. In combination, an internal combustion engine, an engine starting circuit, a carburetor having a choke valve, an automatic choking device for yieldably urging said choke valve toward a closed positon, amanual control switch in said starting circuit, an electro-magnet constructed and arranged to move said choke valve toward an open position against the resistance of said automatic choking device a thermostatic switch in said starting circuit capable of connecting said electro-magnet in said starting circuit after a predetermined interval during which said starting circuit is closed, and automatic means tunetioning to maintain a broken starting circuit during operation of the engine.

JOSEPH SCHWEISS.