Tow bar lift assist system and method

A towed vehicle with tow bar lift assist system, comprising:

• a chassis supported by a plurality of tire assemblies, wherein lower extremities of said tire assemblies define a ground plane;
• a pivot pin coupled to said chassis and defining a pivot axis;
• a tow bar assembly coupled about said pivot pin for rotation about said pivot axis, said tow bar assembly including a tow bar that defines a tow bar axis that is perpendicular to said pivot axis and extends through a free end of said tow bar, said tow bar assembly including a linkage arm that extends radially outward from said pivot axis;
• and
• a lift assist system, including
• a pivot connector directly connected to said linkage arm of said tow bar assembly,
• an actuation shaft coupled to said pivot connector and extending beneath or through said chassis, and
• an elastic support that extends beneath or through said chassis and is coupled to said actuation shaft,
• wherein:
• a reference plane is defined as being coplanar with said pivot axis and parallel to said ground plane;
• said tow bar defines a lowered configuration wherein said free end of said tow bar is below said reference plane;
• said tow bar defines a horizontal configuration wherein said tow bar axis is coplanar with said reference plane;
• said elastic support exerts an assistance force on said actuation shaft to generate an upward moment of said tow bar assembly about said pivot axis, said upward moment A suspending said free end of said tow bar at an equilibrium height above said ground plane in said lowered configuration, said tow bar axis defining an equilibrium angle relative to said reference plane at said lowered configuration;
• and
• said upward moment is generated from said lowered configuration through said horizontal configuration.