Pneumatic accelerator for low emission charge forming devices
AssigneeBriggs & Stratton Corporation
InventorThomas G. Guntly
Life of this patent
Estimating the term…
Abstract
An accelerator having a main body defining a main chamber, a movable member (e.g., a diaphragm) positioned within and dividing the main chamber into a pneumatic chamber and a fuel chamber, and a damping orifice (e.g., in the main body) interconnecting the pneumatic chamber with a gas source (e.g., ambient air). The damping orifice has a cross sectional area less than about 0.002 square inches. To inhibit contamination of the accelerator, a filter can be operatively positioned between the pneumatic chamber and the ambient air.
Claims20
A charge forming device for use with an internal combustion engine, said charge forming device comprising:
- a body having an intake passageway;
- an accelerator device having a pneumatic chamber that is operatively interconnected with said intake passageway such that pressure fluctuations in said intake passageway is communicated to said pneumatic chamber;
- and
- a damper operative with said pneumatic chamber to damp low vacuum pressures communicated to said pneumatic chamber by increasing the pressure applied to said pneumatic chamber to a pressure that is 2 psi to 11 psi greater than the lowest vacuum pressure in said intake passageway, said damper including a damping orifice designed to draw gas from a gas source into said pneumatic chamber in response to low vacuum pressures communicated to said pneumatic chamber.
A charge forming device for use with an internal combustion engine, said charge forming device comprising:
- a body having an intake passageway;
- a main fuel chamber;
- an accelerator device including
- a pneumatic chamber that is operatively interconnected with said intake passageway such that pressure fluctuations in said intake passageway is communicated to said pneumatic chamber;
- and
- a variable volume fuel chamber that is operatively interconnected with said main fuel chamber, wherein the volume of said variable volume fuel chamber is responsive to pressure fluctuations in said pneumatic chamber, said variable volume fuel chamber having a vent passageway in fluid flow communication with said main fuel chamber, wherein said vent passageway is adapted to permit a gas to pass through said vent passageway from said variable volume fuel chamber into said main fuel chamber, but substantially prevents the passage of fuel through said vent passageway.
Dependencies are inferred from the claim text.