Patent ID: 7028371
Filing Date: 2006-04-18
Classification: E05D,E05Y,Y10T

Abstract:
1. A block and tackle window balance system comprising: a track; a translatable block assembly moveably disposed at least partially within the track; a balance spring having a first end fixed relative to the track and a second end coupled to one end of the translatable block assembly; a cord comprising a first cord end and a second cord end, wherein the first cord end is attached to an opposite end of the translatable block assembly and the second cord end is attached to a jamb when installed in a window; a brake comprising a pawl coupled to the translatable block assembly, wherein the pawl pivots to engage the track in response to a rapid acceleration of the translatable block assembly along the track; a cam coupled to the pawl; and a brake shoe in communication with the cam and disposed between the cam and at least a portion of the cord, wherein the pawl rotates the cam as the pawl pivots, thereby causing the brake shoe to engage the cord in response to the rapid acceleration of the translatable block assembly along the track.