Vehicle seat assembly and return spring mechanism

A biasing mechanism for a vehicle seat assembly comprising:

• a support stud sized to be received within a seat back bracket and extend along an axis of rotation of a seat back, the support stud having a first end for fixed connection relative to a vehicle frame, the support stud having a second end opposite to the first end and defining an aperture therethrough;
• a biasing member with a first end region, a second opposed end region, and an intermediate region positioned therebetween, the first end region extending through the aperture in the support stud and fixed relative thereto;
• a support bracket to connect to the seat back, the intermediate region of the biasing member extending through the support bracket and supported for rotation therein;
• and
• a block supported by the support bracket and offset from the axis of rotation, the block contacting the second end region of the biasing member to bias the biasing member as the seat back rotates through a first range of motion, the block spaced apart from the second end region of the biasing member such that the biasing member is unloaded as the seat back rotates through a second range of motion.

A method of installing a vehicle seat assembly, the method comprising:

• rotatably connecting a seat back relative to a seat base via a seat back bracket and a fixed bracket mount such that the seat back rotates about a transverse axis from a first, use position to a second, folded position relative to a seat base;
• positioning a support stud into the seat back bracket;
• connecting the support stud to the fixed bracket mount such that the seat back bracket and seat back rotate relative to the support stud;
• connecting a first end region of a biasing member to the support stud such that the first end region is fixed relative thereto;
• positioning an intermediate region of the biasing member through an aperture in a support bracket connected to the seat back such that the intermediate region of the biasing member is supported for rotation therein;
• connecting a block having a thickness to the support bracket with the block offset from the transverse axis;
• biasing the biasing member by positioning a second end region of the biasing member in contact with the block with the seat back in the first position such that the thickness of the block biases the biasing member to a specified preload;
• and
• in response to a seat back release mechanism being released, rotating the seat back through a first range of motion via the biasing member and rotating the seat back through a second range of motion via an inertia of the seat back, the block contacting the second end region of the biasing member through the first range of motion, the first range of motion including the first position, the block spaced apart from the second end region of the biasing member such that the biasing member is unloaded through the second range of motion, the second range of motion including the second position.