spiral balance

spiral balance

A sash balance using a spirally wound helical spring to compensate for the weight of the sash.
References in periodicals archive ?
In 1948 Caldwell developed the first spiral balance product, called Spirex.
Marvin's Ultimate double-hung has a spiral balance that carries 70 percent of the sash's weight.
All are insulated to keep you warm in winter and cool in summer, with up to 80% solar heat reflection for all year round use.'' The timber range includes vertical sliding sash windows with modern spiral balances or traditional strings and pulleys, all with wool pile draught excluding and A rated glazing.
Modern sash windows have spring-action spiral balances which are not boxed in.