Abstract: A window insert assembly is disclosed having a spring-biased frame construction used to secure the insert within existing window frames of varying size. The insert assembly is particularly useful for mounting interiorly of an existing window pane to form a "double pane" insulative window structure, i.e., by creating a thermal cavity between the interior side of the existing window pane and the window pane of the insert. The insert assembly comprises a solid pane, such as a glass pane, mounted in a first frame. The first frame is received within a second frame which has movable sides for changing the size of the second frame. Springs are provided between the second frame and the first frame, preferably on all four sides of the rectangular window insert assembly, which bias the second frame outwardly relative to the first frame. The size of the second frame is adjustable by pressing one or more sides against this bias to fit the insert within an existing window frame in which it is to be installed.

Abstract: A window insert assembly is disclosed having a spring-biased frame construction used to secure the insert within existing window frames of varying size. The insert assembly is particularly useful for mounting interiorly of an existing window pane to form a "double pane" insulative window structure, i.e., by creating a thermal cavity between the interior side of the existing window pane and the window pane of the insert. The insert assembly comprises a solid pane, such as a glass pane, mounted in a first frame. The first frame is received within a second frame which has movable sides for changing the size of the second frame. Springs are provided between the second frame and the first frame, preferably on all four sides of the rectangular window insert assembly, which bias the second frame outwardly relative to the first frame. The size of the second frame is adjustable by pressing one or more sides against this bias to fit the insert within an existing window frame in which it is to be installed.

Abstract: A multiple-pane, hermetically-sealed, thermal-resistant window with a spacer between adjacent panes for maintaining separation between the panes wherein the corners of the spacer are rigidified and locked by a corner insert which prevents separation of adjacent spacer frame members and wherein the spacer frame members are attached to the window frame to prevent and/or reduce movement of the spacer frame members. The seal around the cavity between adjacent panes is completed after the temperature of the window components and the cavity air is about equal to the temperature of the ambient air. A resistance heating wire is applied to the outside surface of the spacer frame intermediate the adjacent panes of glass.

Abstract: A multiple-pane, hermetically-sealed, thermal-resistant window unit is disclosed having a spacer between adjacent panes for maintaining separation between the panes, wherein the corners of the spacer are rigidified and locked by a corner insert which prevents separation of adjacent spacer frame members and wherein the spacer frame members are attached to the window frame to prevent and/or reduce movement of the spacer frame members. The seal around the cavity between adjacent panes is completed after the temperature of the window components and the cavity air is about equal to the temperature of the ambient air. A resistance heating wire is applied to the outside surface of the spacer frame intermediate the adjacent panes of glass.