Low profile gaseous fuel carburetor

• US 4,894,067 A
• Filed: 11/18/1987
• Issued: 01/16/1990
• Est. Priority Date: 11/18/1987
• Status: Expired due to Fees

• Current Assignee: Carbumatic BV
• Original Assignee: Carbumatic BV
• Inventors: Bayerstock, Richard
• Primary Examiner(s): Woodard, Joye L.
• Application Number:
  US07/121,981
• Time in Patent Office: 790 Days
• Field of Search: 48/180.1, 48/184, 261/41.4, 261/44.8, 261/51, 261/78.2, 74/470, 74/582, 123/527, 123/190 R
• US Class Current: 48/180.1
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 43/00 Engines characterised by operating on gaseous fuels; Plants including such engines engines characterised by the gas-air charge being ignited by compression ignition of an additional fuel F02B7/06; engines convertible from gas to other fuel consumption F02B69/04
• CPC Class Codes: F02M 21/0233 Details of actuators therefor
• CPC Class Codes: F02M 21/0239 Pressure or flow regulators therefor
• CPC Class Codes: F02M 21/042 Mixer comprising a plurality of bores or flow passages
• CPC Class Codes: F02M 21/047 Venturi mixer
• CPC Class Codes: G05G 23/02 self-adjusting
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y10T 74/20006 Resilient connections
• CPC Class Codes: Y10T 74/2146 Longitudinal springs

Abstract

A low profile gaseous fuel carburetor provided with deflector valves to improve mixing of gas and air in a mixture stream of short length. It also shows improved idling and starter valves, and a link for a parallelogram throttle linkage that maintains a correct lever relationship despite operational wear.

Claims

1. A gaseous fuel carburetor comprising:

a body having a passage wall forming a passage having an axis of downstream flow, an upstream air intake port, and a downstream mixture outlet port, said passage incorporating a reduced venturi between said ports;

an adjustable throttle valve means in said passage, said throttle valve means including a rotatable throttle shaft to set the throttle valve means;

said passage wall having a plurality of gas injector ports opening into said passage so as to discharge gas into said passage, and a plurality of deflector vanes on said passage wall, each vane of said plurality of deflector vanes being upstream from and overhanging a respective injector port, each said deflector vane having an upstream facing face, a downstream facing face and a free tip end, said faces extending from said wall into said passage, and sloping downstream, there being substantial spacings between the tip ends of said vanes and between said vanes to permit unimpeded axial flow of air past them; and

a gas supply conduit connected to said gas injector ports for supplying gas to the injector ports.

2. A carburetor according to claim 1 in which a rotary metering valve is mounted to said body said rotary metering valve having an inlet port, a valving chamber, and a valving port in that order, said valving chamber having a cylindrical wall with a valving axis, said valving port being disposed in said valving chamber wall, a valve rotor rotatably mounted in said valving chamber, said rotor having a valving notch with a valving edge which in one rotary position provides only for minimal gas flow, and in other position provides for adjustable selectable gas flow, said valving port being connected to said gas supply conduit, and said inlet port being adapted to receive gas to be metered by said metering valve.

3. A carburetor according to claim 2 in which said throttle shaft and said valve rotor each have a respective center of rotation, the centers of rotation of said throttle shaft and of said valve rotor being spaced apart by a fixed reference spacing, a throttle lever fixed to said throttle shaft to rotate it, and a rotor lever fixed to said rotor to rotate it, a linkage pivotally attached to pivot pins disposed on both levers at pivot points equidistant from said centers of rotation to maintain the separation of the pivot points from one another substantially equal to the reference spacing and defining a separation axis, whereby the two shafts rotate simultaneously through substantially equal rotational angles.

4. A carburetor according to claim 3 in which said linkage comprises:

a pair of identical plates held and laid in flat sliding adjacency to one another, each said plate having a pair of slots located at opposite ends of the plate defining contact surfaces facing in the same direction along the separation axis to engage a respective pin at a respective pivot point, and said plates being laid reversely relative to one another so the contact surfaces of one plate face toward the respective contact surfaces of the other plate, the contact surfaces on both plates being spaced apart by a distance equal to the reference spacing, and resilient bias means connected to said plates in tension so as to draw the contact surfaces against respective pivot pins disposed at said pivot points, and the pivot pins having identical dimensions in contact with said contact surfaces.

5. A carburetor according to claim 4 in which one of said pair of slots on each plate is a keyhole slot, and the other slot of said pair of slots on each plate is open at the opposite end of each plate.

6. A carburetor according to claim 2 in which said rotor further includes a by-pass circuit comprising:

a groove on the rotor extending axially from a position within the inlet port when the valve is in said one rotary position for minimal gas flow to an end of the rotor, said groove including a bore extending from said end into the rotor and branching to an exit port in communication with the valving port when the valve rotor is in said one rotary position, and a spring-loaded poppet valve in said bore, said poppet valve being biased open when pressures respective to starting are presesnt at the valving port, and closed at substantially higher vacuum levels.

7. A carburetor according to claim 6 in which said valving port is in a removable plate.

8. A linkage in combination with two parallel levers for joining said two parallel levers, said levers being rotatable around and projecting from respective centers of rotation, each of said levers having a respective pin mounted at a distance from its respective center, said distances being equal, said linkage maintaining constant the spacing between the pins despite wear of the linkage or of the pins, said linkage comprising:

a pair of identical plates held and laid in flat sliding adjacency to one another, each of said plates having a pair of slots located at opposite ends of the plate defining contact surfaces facing in the same direction along a separation axis defined between the contact surfaces to engage a respective pin, and said plates being laid reversely relative to one another so the contact surfaces of one plate face toward the respective contact surfaces of the other plate, the contact surfaces on each of said plates being spaced apart by a distance equal to the reference spacing, and resilient bias means connected to said plates in tension so as to draw the contact surfaces against respective pins, and the pins having identical dimensions in contact with said contact surfaces.

9. A linkage according to claim 8 in which one of said pair of slots on each plate is a keyhole slot, and the other slot of said pair of slots on each plate is open at the opposite end of each plate.

10. A gaseous fuel carburetor comprising:

a body having a passage wall forming a passage having an axis of downstream flow, an upstream air intake port, and a downstream mixture outlet port, said passage incorporating a reduced venturi between said ports;

an adjustable throttle valve means in said passage, said throttle valve means including a rotatable throttle shaft to set the throttle valve means;

said passage wall having a plurality of gas injector ports opening into said passage so as to discharge gas into said passage;

a rotary metering valve mounted to said body, said metering valve having an inlet port, a valving chamber, and a valving port in that order, said valving chamber having a cylindrical wall with a valving axis said valving port being disposed in said valving chamber wall, a valve rotor rotatably mounted in said valving chamber, said valve port being connected to said gas supply conduit, and said inlet port being adapted to receive gas to be metered by said metering valve.

said throttle shaft and said valve rotor each having a respective center or rotation, the centers of rotation of said throttle shaft and of said valve rotor being spaced apart by a fixed reference spacing, a throttle lever being fixed to said throttle shaft to rotate it, and a rotor lever being fixed to said rotor to rotate it; and

a linkage pivotally attached to pivot pins and disposed on both levers at pivot points equally distant from said centers of rotation to maintain the separation of the pivot points from one another substantially equal to the reference spacing and defining a separation axis, whereby the two shafts rotate simultaneously through substantially equal rotation angles,

said linkage comprising a pair of identical plates held in and laid in flat sliding adjacency to one another, each of said plates having a pair of slots located at opposite ends of the plate defining contact surfaces facing in the same direction along the separation axis to engage a respective pin at a respective pivot point, and said plates being laid reversely relative to one another so that the contact surfaces of one plate face toward the respective contact surfaces of the other plate, the contact surfaces on both plates being spaced apart by a distance equal to the reference spacing, and resilient bias means connected to said plates in tension so as to draw the contact surfaces against respective pivot pins, and the pivot pins having identical dimensions in contact with said contact surfaces.