Patent ID: 7685974
Filing Date: 2010-03-30
Classification: F02B

Abstract:
1. A variable compression ratio piston and rod assembly for an internal combustion engine, said assembly comprising: a piston having a pin bore centered along a first axis; a piston pin disposed in said pin bore; a connecting rod having a lower crank end and an upper piston end, said upper piston end including a rod bore centered along a second axis that is offset from and parallel to said first axis of said pin bore, wherein, when operatively disposed in an internal combustion engine, said upper piston end of said connecting rod is subjected to a plurality of acceleration vectors including stroking acceleration vectors extending along an axis passing perpendicularly through said first axis, angular acceleration vectors centered around said first axis, and centrifugal acceleration vectors radiating from said first axis; an eccentric bushing pivotally interconnecting said piston pin and said rod bore, said eccentric bushing including a bore along said first axis that receives said piston pin and an eccentric outer journaled portion carried in said rod bore, said eccentric bushing being rotatable so as to effect a spatial displacement between said piston and said connecting rod to effectively alter the compression ratio created by said assembly when operatively disposed in an internal combustion engine; a latch moveably carried on said connecting rod adjacent said upper piston end for movement between a latched position in which said eccentric bushing is fixed in one of at least two rotated positions, and an unlatched position in which said eccentric bushing is freely rotatable relative to said connecting rod; and said latch constrained to movement relative to said upper piston end exclusively in directions generally perpendicular relative to each of said stroking, angular and centrifugal acceleration vectors.