Internal combustion engine system for exhaust emissions control

Claim 1

IN AN INTERNAL COMBUSTION ENGINE HAVING A CYLINDER, MEANS FOR REDUCING THE AMOUNT OF RESIDUAL COMBUSTIBLES IN THE PRODUCTS OF COMBUSTION FROM SAID CYLINDER COMPRISING AN EXHAUST SYSTEM LEADING FROM AN EXHAUST PORT OF SAID CYLINDER, MEANS FOR PROVIDING AIR IN AT LEAST STOICHIOMETRIC RATIO AT SAID EXHAUST PORT FOR COMBUSTION OF SAID RESIDUAL COMBUSTIBLES AMONG THE EXHAUST PRODUCTS IN SAID EXHAUST SYSTEM, AND MEANS FOR CONTROLLING THE BACK PRESSURE IN SAID EXHAUST SYSTEM COMPRISING VALVE MEANS POSITIONED THEREIN DOWNSTREAM FROM SAID EXHAUST PORT HAVING PROVISIOINS RESTRICTING MASS FLOW OF SAID EXHAUST PRODUCTS AT THE LOWER SPEEDS ABOVE IDLE THEREBY MAINTAINING FROM SHORTLY AFTER INITIATION OF COMBUSTION IN SAID INTERNAL COMBUSTION ENGINE A SUBSTANTIALLY CONSTANT BACK PRESSURE HIGHER THAN THE NORMAL BACK PRESSURE OF SAID EXHAUST SYSTEM WITHOUT SAID VALVE MEANS AND OPENING AT THE HIGHER SPEEDS AND MASS FLOW RATES WHEN SAID NORMAL BACK PRESSURE WITHOUT SAID VALVE MEANS IS ABOVE THE IMPOSED BACK PRESSURE.