Patent ID: 7716875

Claim:
A window comprising: a first pane assembly mounted in an opening, the first pane assembly comprising: a first pane; a second pane; and a first seal disposed between the first and second panes to form a sealed chamber between the first and second panes; and a second pane assembly also mounted in the opening, at least one of the first and second pane assemblies being slidable with respect to the other pane assembly between an open position and a closed position, the second pane assembly comprising: a third pane; a fourth pane longer than the third pane; and a second seal disposed between the third and fourth panes to form a sealed chamber between the third and fourth panes, wherein when the first and second pane assemblies are in the closed position, the fourth pane of the second pane assembly extends beyond the third pane and beyond the second seal so as to overlap with the first pane assembly.