Dual fuel supply system

• US 4,499,887 A
• Filed: 01/28/1983
• Issued: 02/19/1985
• Est. Priority Date: 01/28/1983
• Status: Expired due to Term

• Current Assignee: Outboard Marine Corporation (Bombardier Incorporated)
• Original Assignee: Outboard Marine Corporation (Bombardier Incorporated)
• Inventors: Billingsley, Henry C., Clark, Amos M.
• Primary Examiner(s): Cross, E. Rollins
• Application Number:
  US06/461,866
• Time in Patent Office: 753 Days
• Field of Search: 123/575, 123/187.5 R, 123/179 G, 123/1 A, 123/27 GE, 123/515
• US Class Current: 123/575
• CPC Class Codes: F02M 1/16 Other means for enriching fuel-air mixture during starting; Priming cups; using different fuels for starting and normal operation
• CPC Class Codes: F02M 13/06 the carburettors using different fuels

Abstract

The dual fuel supply system for an internal combustion engine has a carburetor including a fuel/air induction passage having means defining a low pressure zone and a secondary orifice and further including a cavity communicating with the fuel induction passage through the secondary orifice. A first or primary fuel supply includes a first float bowl connected to a source of a primary fuel, such as kerosene, a first float controlled valve operable to control the supply of the primary fuel to the first float bowl, a fuel nozzle for supplying the primary fuel from the first float bowl to the low pressure zone, and a conduit connecting the first float bowl in communication with the carburetor cavity. The second or secondary fuel supply includes a second float bowl communicable with the carburetor cavity and connected to a source of a second or secondary fuel, such as gasoline, and a second float controlled valve operable to control the supply of the secondary fuel to the second float bowl. In one embodiment, the carburetor includes a throttle valve located downstream of the low pressure zone and a priming fuel port located downstream of the throttle valve. A primer pump having an inlet connected in communication with the priming fuel port can be operated to selectively introduce a quantity of the secondary fuel into the induction passage to facilitate engine starting.

Claims

1. A fuel supply system comprising a carburetor including an fuel/air induction passage having means defining a low pressure zone, a secondary orifice communicating with said induction passage downstream of said low pressure zone, a cavity communicating with said secondary orifice, first fuel supply means including a source of a first fuel and means operable to simultaneously supply the first fuel to said low pressure zone and to said cavity, and second fuel supply means including a source of a second fuel and means operable to supply the second fuel to said cavity simultaneously with the first fuel.

2. A fuel supply system according to claim 1 wherein said first fuel supply means includes a first float bowl communicating with said low pressure zone and with said cavity and a first float controlled valve communicable with the first fuel source and operable to control the supply of the first fuel to said first float bowl, and wherein said second fuel supply includes a second float bowl communicating with said cavity and a second float controlled valve communicable with the second fuel source and operable to control the supply of the second fuel to said second float bowl.

3. A fuel supply system according to claim 2 including a fuel nozzle communicating between said first float bowl and said low pressure zone and a conduit connecting said first float bowl in communication with said cavity.

4. A fuel supply system according to claim 1 wherein said carburetor includes a throttle valve located downstream of said low pressure zone and a priming fuel port located downstream of said throttle valve and communicating with said induction passage.

5. A fuel supply system according to claim 4 including a primer pump having an inlet connected in communication with said second fuel source and an outlet connected in communication with said priming fuel port for selectively introducing a quantity of the second fuel into said induction passage through said priming fuel port.

6. A fuel supply system comprising a carburetor including a fuel/air induction passage having means defining a low pressure zone and a secondary orifice communicating with said induction passage downstream of said low pressure zone, a cavity communicating with said induction passage through said secondary orifice, first fuel supply means including a first fuel bowl connected to a source of a first fuel, a first float controlled valve operable to control the supply of the first fuel to said first float bowl, a fuel nozzle communicating between said first float bowl and said low pressure zone, and a conduit communicating said first float bowl with said cavity such that the first fuel is simultaneously supplied to said pressure zone and to said cavity, and second fuel supply means including a second float bowl communicating with said cavity and connected to a source of a second fuel, and a second float control valve operable to control the supply of the second fuel to said second float bowl such that the first and second fuels are blended together in said cavity prior to introduction into said induction passage.

7. A fuel supply system according to claim 6 wherein said carburetor includes a throttle valve located downstream of said low pressure zone and a priming fuel port located downstream of said throttle valve and communicating with said induction passage, and wherein said system further includes a primer pump having an inlet connected in communication with said second float bowl and an outlet connected in communication with said priming fuel port for selectively introducing a quantity of the second fuel into said induction passage through said priming fuel port.

8. A fuel supply system comprising a carburetor including an fuel/air induction passage having therein a throttle valve, a secondary orifice communicating with said air induction passage adjacent to said throttle valve, first fuel supply means including a source of a first fuel and means operable to simultaneously supply the first fuel to said secondary orifice and to said induction passage upstream of said throttle, and second fuel supply means including a source of a second fuel and means operable to supply the second fuel to said secondary orifice simultaneously with the first fuel.

9. A fuel supply system according to claim 8 wherein said first fuel supply means includes a first float bowl communicating with said air induction passage and with said secondary orifice and a first float controlled valve communicable with the first fuel source and operable to control the supply of the first fuel to said first float bowl, and wherein said second fuel supply includes a second float bowl communicating with said secondary orifice, and a second float controlled valve communicable with the second fuel source and operable to control the supply of the second fuel to said second float bowl.

10. A fuel supply system comprising a carburetor including a fuel/air induction passage having therein a throttle valve, and a secondary orifice communicating with said induction passage adjacent to said throttle valve, first fuel supply means including a first fuel bowl connected to a source of a first fuel, a first float controlled valve operable to control the supply of the first fuel to said first float bowl, a fuel nozzle communicating between said first float bowl and said air induction passage upstream of said throttle valve, and a conduit communicating said first float bowl with said secondary orifice such that the first fuel is simultaneously supplied to said fuel nozzle and to said secondary orifice, and second fuel supply means including a second float bowl communicating with said secondary orifice and connected to a source of a second fuel, and a second float control valve operable to control the supply of the second fuel to said second float bowl such that the first and second fuels are simultaneously supplied to said secondary orifice for introduction into said induction passage.