Patent ID: 6058900
Filing Date: 2000-05-09
Classification: F01M

Abstract:
An internal combustion engine, comprising:a first cylinder formed in an engine block;a first piston disposed in said first cylinder for reciprocating motion therein;a first crankcase connected in fluid communication with said first cylinder, a first pressure within said first crankcase having a first magnitude which varies in response to said reciprocating motion of said first piston within said first cylinder;a second cylinder formed in said engine block, said second cylinder being disposed below said first cylinder during normal operation of said engine;a second piston disposed in said second cylinder for reciprocating motion therein;a second crankcase connected in fluid communication with said second cylinder, a second pressure within said second crankcase having a second magnitude which varies in response to said reciprocating motion of said second piston within said second cylinder;a wall disposed between said first and second cylinders; anda fluid passage formed through said wall, said fluid passage being alternately blocked and unblocked by said second piston as said second piston moves in said reciprocating motion within said second cylinder, said fluid passage being unblocked for at least a portion of a period of time when said first magnitude of said first pressure within said first crankcase exceeds said second magnitude of said second pressure within said second crankcase to allow a fluid to pass through said fluid passage from said first cylinder into said second cylinder.