Patent ID: 6860066

Claim:
In a tilt-in window assembly having a sash and tracks that extend along opposite sides of the sash, wherein the sash is selectively positionable between a non-tilted position and a tilted position, a counterbalance system for the sash, comprising: tilt posts extending from the opposites sides of the sash, wherein each of the tilt post extends into a retrospective one of the tracks; a respective brake structure coupled to each of said tilt posts and disposed within a respective one of the tracks, each said brake structure being free moving in the respective track when in a first orientation and creating an interference fit with the respective track when rotated to a second orientation, wherein said tilt posts retain said brake structures in said first orientation when the sash is in said non-tilted position, and wherein said tilt posts rotate said brake structures into said second orientation when the sash is moved from said non-titled position to said tilted position; and a plurality of wound springs, each of said wound springs having a free end anchored in a respective one of the tracks, wherein each of said wound springs define a central opening, and wherein each of said brake structures extends into the central opening of a respective one of said wound springs, thereby supporting said wound spring within the respective one of the tracks; wherein said brake structures bias said wound springs against the tracks when said brake structures are in said second orientation.