Two-stroke internal combustion engine

Abstract

This disclosure relates to a two-stroke engine comprising an engine frame forming a cylinder, and a piston mounted for reciprocating movement in the cylinder. The engine frame further includes a crankcase chamber and inlet flow passages for fresh mixture, which form a crankcase compression arrangement. The cylinder includes a cylinder wall having an intake port and an exhaust port. The piston is movable in compression and combustion strokes between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position in the cylinder, and the piston includes a piston skirt. Movement of the piston toward the BDC position opens the intake port and the exhaust port, and fresh mixture flows from the crankcase chamber into the cylinder and scavenges the burned gases through the exhaust port. When the piston moves toward the TDC position, the inlet flow passage is opened which allows fresh mixture to flow into the crankcase chamber. The exhaust port is also opened, and burned gases in the exhaust port are also drawn into the crankcase chamber and combined with the fresh mixture.

Dependencies are inferred from the claim text.