Drive linkage for reciprocating engine

In a reciprocating engine of the type in which a piston travels in a cylinder between top dead center and bottom dead center positions, and in which a pair of parallel counter-rotating cranks having crank arms joined by respective connecting rods to said piston and have axes that define a crank plane, such that the rotary motion of the cranks for travel of the piston from the top dead center position to the bottom dead center position is significantly different from 180 degrees, and the rotary motion of the cranks for the travel of the piston from the bottom dead center position to the top dead center position is correspondingly different from 180 degrees in the complementary sense, and wherein the engine further comprises a piston rod that extends from said piston and between the crank axes and is pivotally coupled to said connecting rods such that the pivotal couplings of said piston rod to said connecting rods remains disposed at the side of said crank plane remote from said piston for all travel of said piston between said top dead center and bottom dead center positions;

• the improvement wherein the piston travel from top dead center to bottom dead center corresponds to crank motion significantly greater than 180 degrees and the piston travel from bottom dead center to top dead center corresponds to crank motion significantly greater that 180 degrees;
• and the crank arms, the connecting rods, and separation of the cranks are related such that for a given rotation angle of said cranks near top dead center, said piston descends from top dead center substantially at least twice as far as said piston ascends toward top dead center, whereby dwell time at top dead center is significantly reduced.