Charge forming device with idle and open throttle choke control
View Patent ↗A charge forming device may include a body having a fuel and air mixing passage, a throttle valve and choke valve moveable between first and second positions to control at least in part the fluid flow in the fuel and air mixing passage, and throttle and choke control members associated with the throttle and choke valves, respectively. The choke control member may also be associated with an engine starting system so that the choke valve is moved to its second position upon actuation of the starting system. The choke control member is selectively associated with the throttle control member to hold the choke control member in a position spaced from its first position. In this manner, the throttle valve and choke valve may be automatically positioned in a desired position for starting of the engine upon actuation of the engine starting system.
1. A charge forming device for an engine, comprising:
a body having a fuel and air mixing passage;
a throttle valve that is movable between a first position and a second wide open throttle position to control at least in part the fluid flow in the fuel and air mixing passage;
a choke valve that is movable between a first open position and second at least partially closed position to control at least in part the fluid flow in the fuel and air mixing passage;
a throttle control member associated with the throttle valve; and
a choke control member associated with the choke valve so that when the choke valve is moved from its first position to its second position the choke control member is selectively engaged with the throttle control member in either its first or second positions to hold the choke control member in its second at least partially closed position spaced from its first position to provide an enriched fuel and air mixture to facilitate starting a cold engine.
2. The device of claim 1 wherein the choke valve is closed when it is in its second position, and wherein the choke valve has an intermediate start position between its first and second positions and the start position is defined by engagement of the choke control member with the throttle control member.
3. The device of claim 2 which also includes a biasing member that yieldably biases the choke valve to its first position, and wherein the choke valve is automatically moved from its first position to its second position by actuation of an engine starting system and then the choke valve is returned from its second position toward its first position by the biasing member until the choke control member engages the throttle control member.
4. The device of claim 3 wherein the throttle valve is in its first position when the starting system is actuated.
5. The device of claim 4 wherein the first position of the throttle valve is its idle position.
6. The device of claim 4 wherein the choke control member engages the throttle control member when the choke valve is rotated toward its second position and thereby moves the throttle valve away from its first position and continued engagement of the choke control member and throttle control member maintains the throttle valve in a position spaced from its first position.
7. The device of claim 3 wherein the throttle valve is in its second position when the starting system is actuated.
8. The device of claim 6 wherein when the throttle valve is in its second position it is wide open.
9. The device of claim 8 wherein the throttle control member includes a first portion adapted to engage the choke control member when the throttle valve is in its first position and a second portion adapted to engage the choke control member when the throttle valve is in its second position.
10. The device of claim 1 which also includes an engine starting system, wherein the starting system includes a feature connected to the choke control member to automatically move the choke valve as the engine starting system is actuated.
11. The device of claim 1 wherein the choke control member includes a first cam that engages and displaces the throttle control member from its first position when the choke valve is moved to its second position, and a first catch that engages the throttle control member to releasably hold the positions of the throttle valve and the choke valve.
12. The device of claim 1 wherein the choke control member includes a second cam that engages the throttle control member when the choke valve is rotated to its second position and the throttle control member is in its second position, and a second catch that engages the throttle control member to releasably hold the positions of the throttle valve and the choke valve.
13. The device of claim 1 which also comprises:
the first throttle control member and a second throttle control member both associated with the throttle valve;
the first choke control member and a second choke control member both associated with the choke valve, the first choke control member being engageable with the first throttle control member when the throttle valve is in its first position and the choke valve is in its second position, and the second choke control member being engageable with the second throttle control member when the throttle valve is in its second position and the choke valve is in its second position.
14. The device of claim 13 wherein the throttle valve includes a throttle valve shaft, the first throttle control member is carried on the throttle valve shaft, the second throttle control member is carried on the throttle valve shaft, and an axis of the fuel and air mixing passage extends between the first throttle control member and the second throttle control member.
15. The device of claim 14 wherein the throttle valve shaft extends through the fuel and air mixing passage and the first throttle control member is carried adjacent one end of the throttle valve shaft and the second throttle control member is carried adjacent the opposite end of the throttle valve shaft.
16. The device of claim 13 wherein at least one of the second choke control member and the second throttle control member include a ramped surface adapted to engage and move over a portion of the other of the second choke control member and the second throttle control member to permit the throttle valve and the choke valve to be moved to their second positions.
17. The device of claim 16 wherein the throttle valve includes a throttle valve shaft and the choke valve includes a choke valve shaft and at least one of the throttle valve shaft or the choke valve shaft is constructed and arranged to permit the ramped surface to move over a portion of the other control member.
18. The device of claim 17 wherein the choke valve shaft is formed from a flexible material.
19. The device of claim 16 wherein at least one of the throttle valve and the choke valve is capable of being rotated beyond its second position and relative to the other valve.
20. The device of claim 19 wherein said at least one of the throttle valve and the choke valve is yieldably biased toward its first position and when rotated beyond its second position, the bias tends to rotate the valve back to its second position.
21. The device of claim 13 wherein the first position of the throttle valve is at least one of its idle position or a start position.
22. The device of claim 13 wherein the second position of the throttle valve is at least one of its wide open position or a start position.
23. The device of claim 13 wherein one of the first or second choke control members includes a first cam that engages and displaces a corresponding one of the first and second throttle control members from its first position when the choke valve is moved to its second position, and a first catch that engages the corresponding one of the first and second throttle control members to releasably hold the positions of the throttle valve and the choke valve.
24. The device of claim 13 wherein one of the first or second choke control members includes a second cam that engages a corresponding one of the first and second throttle control members when the choke valve is rotated to its second position and the corresponding one of first and second throttle control members is in its second position, and a second catch that engages the corresponding one of the throttle control members to releasably hold the positions of the throttle valve and the choke valve.