Patent ID: 6378169
Filing Date: 2002-04-30
Classification: E05D,Y10T

Abstract:
A system mounting a plurality of constant force curl springs in a shoe channel of a window to counterbalance a sash shoe running vertically within the channel, the system comprising:a. a mounting block secured in the shoe channel to engage and support a first spring coil above the mounting block; b. a second spring coil arranged within the shoe channel above the first spring coil so that outer convolutions of the first and second spring coils engage each other; c. a free end of the spring of the first coil being connected to one side of a sash shoe arranged within the shoe channel below the mounting block, and a free end of the spring of the second coil being connected to an opposite side of the sash shoe so that the first and second spring coils counterrotate against each other as the shoe moves up and down within the channel; d. each of the free spring ends having a barb cut from spring material and bent away from spring material to form a spring retainer; and e. the shoe having molded slots positioned and dimensioned to receive the first and second spring ends, the slots having widened recess regions configured to receive the barbs and thereby hold the spring ends from vertical withdrawal from the slots.