Patent ID: 6857228

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: two tilt post brackets, each of said tilt post brackets having a vertical section and a horizontal section that protrudes perpendicularly from said vertical section wherein said vertical section of each of said tilt post brackets is mounted to a respective one of the opposite sides of the sash; each horizontal section of said tilt post brackets includes a brake structure disposed within a respective one of the tracks, said brake structures being free moving in the tracks when in a first orientation and creating an interference fit with the tracks when rotated to a second orientation, wherein said tilt post brackets retain said brake structures in said first orientation when the sash is in said non-tilted position, and wherein said tilt post brackets rotate said brake structures into second orientation when the sash is moved from said non-tilted 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 wound spring defines a central opening, and wherein each of said brake structures extends the central opening of a respective one of said wound springs, thereby supporting wound springs within the tracks; and wherein said brake structures bias said wound springs against the tracks when said brake structures are in said second orientation.