System for regulating the fuel supply of an internal combustion engine

In an internal-combustion engine for an automotive vehicle, provided with a carburetor fed from a fuel pump by way of interposed pressure-regulating means for supplying a fuel/air mixture under the control of an accelerator to an alternately expanding and contracting combustion chamber, the improvement wherein said carburetor comprises:

• a main duct provided with a constricted throat forming a first air inlet and with a first outlet leading to said combustion chamber;
• an ancillary duct of smaller cross-section than said main duct provided with a constricted throat forming a second air inlet and with a second outlet leading to said combustion chamber;
• at least one first butterfly valve in said main duct linked with said accelerator for displacement between a wide-open position and a fully closed position;
• a second butterfly valve in said ancillary duct ganged with said first butterfly valve for displacement by said accelerator between a wide-open position coinciding with the wide-open position of said first butterfly valve and a throttling position coinciding with said fully closed position;
• a first injection nozzle opening into said main duct between said first inlet and said first butterfly valve and communicating with said pressure-regulating means for receiving fuel therefrom;
• a second injection nozzle opening into said ancillary duct between said second inlet and said second butterfly valve and communicating with said pressure-regulating means for receiving fuel therefrom, said pressure-regulating means including a level stabilizer and a buffer reservoir above said level stabilizer, said buffer reservoir and said level stabilizer being each provided with a float valve, said buffer reservoir communicating with said fuel pump and being provided with a discharge line extending to said level stabilizer for feeding fuel thereto exclusively by gravity, said buffer reservoir being further provided with an overflow line for returning excess fuel to an intake of said fuel pump;
• a check valve in said overflow line for preventing the return of fuel to said buffer reservoir by reverse surges, said check valve having an upright housing with an inlet port near its top connected to said buffer reservoir and an outlet port near its bottom connected to said intake;
• a plug vertically slidable between a lower limiting position blocking said outlet port and an upper limiting position unblocking said outlet port;
• float means in said housing elevatable by a rising accumulation of fuel therein;
• abutment means on said plug engageable by said float means with lost motion for entraining said plug into said lower limiting position upon a lowering of the fuel accumulation below a predetermined first level and entraining said plug into said upper limiting position upon a rising of the fuel accumulation above a predetermined second level;
• and
• retaining means effective upon disengagement of said float means from said abutment means for holding said plug in the limiting position last reached.

In an internal-combustion engine for an automotive vehicle, provided with a carburetor fed from a fuel pump by way of pressure-regulating means for supplying a fuel/air mixture under the control of an accelerator to an alternately expanding and contracting combustion chamber, the improvement wherein said pressure-regulating means comprises:

• a level stabilizer including a bowl provided with first float means;
• a buffer reservoir provided with second float means and located above said bowl, said buffer reservoir communicating with said fuel pump;
• a discharge line extending from said buffer reservoir to said bowl for feeding fuel thereto exclusively by gravity, said buffer reservoir being provided with an overflow line for returning excess fuel to an intake of said fuel pump;
• a check valve in said overflow line for preventing the return of fuel to said buffer reservoir by reverse surges, said check valve having an upright housing with an inlet port near its top connected to said buffer reservoir and an outlet port near its bottom connected to said intake;
• a plug vertically slidable between a lower limiting position blocking said outlet port and an upper limiting position unblocking said outlet port;
• float means in said housing elevatable by a rising accumulation of fuel therein;
• abutment means on said plug engageable by said float means with lost motion for entraining said plug into said lower limiting position upon a lowering of the fuel accumulation below a predetermined first level and entraining said plug into said upper limiting position upon a rising of the fuel accumulation above a predetermined second level;
• and
• retaining means effective upon disengagement of said float means from said abutment means for holding said plug in the limiting position last reached.

In an internal-combustion engine for an automotive vehicle, provided with a carburetor fed from a fuel pump by way of pressure-regulating means for supplying a fuel/air mixture under the control of an accelerator to an alternately expanding and contracting combustion chamber, the improvement wherein said pressure-regulating means comprises:

• a buffer reservoir provided with float means and communicating with said fuel pump;
• a discharge line extending from said buffer reservoir to said carburetor for feeding fuel thereto, said buffer reservoir being provided with an elevated outlet and an overflow line extending from said outlet for returning excess fuel to an intake of said pump;
• and
• a check valve in said overflow line below the level of said outlet for preventing the return of fuel to said buffer reservoir by reverse surges, said check valve having an elongate housing which extends generally horizontally in the direction of travel of the vehicle and is provided with an inlet port and an outlet port at opposite ends and with a valve body freely movable in said housing between said inlet and outlet ports for entrainment by surging fuel toward said inlet port while being normally spaced from the latter, said inlet port being connected to said buffer reservoir, said outlet port being nonblockable by said valve body and leading to a fuel tank communicating with said intake.