Two stroke engine having reduced emissions
OwnerJohn Herbert Beveridgeinventor
Life of this patent
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Abstract
A simple, piston ported, two stroke engine having low weight, small size, low fuel consumption, enhanced power output and reduced exhaust emissions. A rotary exhaust valve adjacent to the cylinder exhaust ports closes the exhaust at completion of cylinder blowdown and as the cylinder inlet ports open. A crankcase pump forces fresh, cold, dense air plus fuel mixture into the cylinder via the cylinder inlet ports. Thus, the cylinder exhausting process is separate from the cylinder filling process and no air plus fuel mixture flows out the exhaust. Also, to ensure reliable ignition every cycle, a uniquely contoured top surface on the piston concentrates and delivers compressed, dense, air plus fuel mixture to the ignitor in the combustion chamber.
Claims16
A method for exhausting and filling the cylinder of a two stroke engine with negligible loss of air plus fuel mixture comprising the steps of:
- a. igniting a compressed air plus fuel mixture in a combustion chamber thereby forming hot, high pressure products of combustion, and
- b. expanding said hot, high pressure products of combustion in said cylinder during the downstroke of its piston thereby doing work, and
- c. opening an exhaust valving means allowing said products of combustion to outflow said cylinder during the downstroke of said piston, and
- d. substantially closing said exhaust valving means as an inlet valving means is opening, and
- e. using a pumping means to force air plus fuel mixture into said cylinder via said inlet valving means, and
- f. using the connecting rod of said two stroke engine as a pumping element of said pumping means, and
- g. closing said inlet valving means during the upstroke of said piston, and
- h. compressing said air plus fuel mixture in said cylinder in preparation for ignition of said compressed air plus fuel mixture in said combustion chamber,
- whereby said cylinder is exhausted and filled with air plus fuel mixture with negligible outflow of air plus fuel mixture via said exhaust valving means.
A method for exhausting, filling and supercharging a two stroke engine cylinder comprising the steps of:
- a. igniting a compressed air plus fuel mixture in a combustion chamber thereby forming hot, high pressure products of combustion, and
- b. expanding said hot, high pressure products of combustion in a cylinder during the downstroke of a piston thereby doing work, and
- c. opening an exhaust valving means allowing said products of combustion to outflow said cylinder, and
- d. substantially closing said exhaust valving means as an inlet valving means is opening, and
- e. using a crankcase pump to force air plus fuel mixture into said cylinder via said inlet valving means, and
- f. closing said inlet valving means during the upstroke of said piston, and
- g. compressing said air plus fuel mixture in said cylinder in preparation for ignition of said compressed air plus fuel mixture in said combustion chamber,
- whereby said cylinder is exhausted, filled and supercharged with air plus fuel mixture.
A two stroke engine having reduced emissions comprising:
- at least one cylinder having a combustion chamber,
- at least one piston reciprocatable in said cylinder,
- mechanical means causing said piston to reciprocate in said cylinder,
- said combustion chamber containing hot, high pressure products of combustion when said piston is near top dead center,
- said piston expanding said products of combustion during its downstroke,
- said cylinder having exhaust valving means,
- said exhaust valving means opening at a predetermined position during the downstroke of said piston,
- said exhaust valving means allowing expanded products of combustion to exit from said cylinder,
- said cylinder having inlet valving means,
- said inlet valving means opening at a predetermined position during the downstroke of said piston,
- said inlet valving means in communication with a source of pressurized air plus fuel mixture,
- said exhaust valving means substantially closing at a predetermined position during the downstroke of said piston,
- said source of pressurized air plus fuel mixture filling said cylinder via said inlet valving means,
- said inlet valving means closing at a predetermined position during the upstroke of said piston,
- whereby said cylinder is exhausted and filled with air plus fuel mixture while incurring a negligible outflow of air plus fuel mixture via said exhaust valving means.
Dependencies are inferred from the claim text.