Patent ID: 6769480
Filing Date: 2004-08-03
Classification: B60H

Abstract:
An apparatus for controlling the temperature of an air flow from a temperature control system, said apparatus comprising:a blend door for blocking air flow, said blend door having a plurality of positions each blocking different amounts of air flow, said blend door being rotatable about a first axis between each of said plurality of positions; an output gear secured to said blend door, said output gear being rotatable to rotate said blend door between each of said plurality of positions, said blend door being effective to provide force impeding rotation of said output gear in a first rotation direction and facilitating rotation of said output gear in a second rotation direction; and a biasing mechanism for facilitating rotation of said output gear in a the first rotation direction and impeding rotation of said output gear in the second rotation direction opposite said first rotation direction such that the torque necessary to rotate said output gear in said first rotation direction is substantially equal to the torque necessary to rotate said output gear in said second rotation direction, said biasing mechanism including a ramping surface and a projecting member which biasingly engages said ramping surface and which applies force to said ramping surface facilitating rotation of said output gear in the first rotation direction and impeding rotation of said output gear in the second rotation direction.