Patent ID: 7191872

Claim:
A material handling vehicle comprising: a truck body; a fork assembly fixed to said truck body, and movable vertically relative to said truck body, said fork assembly having a proximal end and a distal end, said proximal end being proximal said truck body; a fork trail assembly mounted to said fork assembly proximal said fork assembly distal end, and having an extended position and a retracted position to support said distal end as said fork assembly moves vertically relative to said truck body; a link member having one end pivotally connected to said fork trail assembly and an opposing end extending toward said proximal end of said fork assembly, wherein said link member exerts a force on said fork trail assembly to move said fork trail assembly between said extended position and said retracted position; a bell crank having a first leg and a second leg, said first leg being pivotally connected to said link member opposing end, and said second leg being pivotally connected to said truck body; and a pin having an eccentric body pivotally connecting said bell crank to said fork assembly, and defining a bell crank pivot axis at the junction of said bell crank first and second legs, wherein rotation of said pin moves said bell crank pivot axis horizontally relative to said fork trail assembly and vertically relative to said truck body, and horizontal movement of said pivot axis relative to said fork trail assembly exerts a force on said link member that is transmitted by said link member to said fork trail assembly to move said fork trail assembly toward one of said extended position and said retracted position to change the height of said fork assembly distal end relative to said fork assembly proximal end, and vertical movement of said pivot axis relative to said body changes the height of said fork assembly proximal end relative to said fork assembly distal end.