Patent ID: 6886297

Claim:
An insulating glazing window sash comprising: a sash frame made of at least two sash sections having their ends in contact with one another, each of the sash sections have a monolithic cross section, the cross section defined by a peripheral surface, opposed outer side surfaces defined as a first outer side surface and a second outer side surface and two grooves defined as a first groove and a second groove, the grooves spaced from one another and extending between and along the opposed outer side surfaces, each of the grooves has a base and spaced walls extending from the base in a direction away from the peripheral surface of the sash frame defined as a first direction, the base of the first groove spaced a distance from the peripheral surface different than the base of the second groove and the first groove adjacent and spaced from the first outer side surface and the second groove adjacent and spaced from the second outer side surface wherein the distance between the spaced walls of the first groove decrease as the distance from the base of the first groove in the first direction increases; a first sheet having marginal and peripheral edges in the first groove of the sash sections, and a second sheet having marginal and peripheral edges in the second groove of the sash sections.