US Patent 11352821 Inverted constant force window balance having slidable coil housing

An inverted constant force window balance system has a carrier assembly including a housing with a first and a second housing wall, a coil spring with a free end, and a shoe assembly slidably coupled to the housing. The shoe assembly includes a first and a second shoe face. The housing slides between a first and a second position relative to the shoe assembly. When in the first position, the first and second housing walls are substantially non-coplanar with the first shoe face, and when in the second position, the first housing wall is substantially coplanar with the first shoe face and substantially non-coplanar with the second shoe face. The shoe assembly receives a pivot bar from a window sash and extends a brake upon rotation thereof. The balance system also includes a mounting bracket releasably coupled to the housing and coupled to the free end of the coil spring.