Abstract: A joint structure for joining two adjacent window frames includes a mullion body disposed between two opposed vertical frame members on the interior side of the window fames and connected to the vertical frame members by a pair of screws extending loosely through a pair of horizontal oblong holes, respectively, in the mullion body and threaded to the vertical frame members, and an elastic backup member disposed between the vertical frame members on the exterior side of the window frames. The vertical frame members and the mullion body disposed therebetween are relatively movable in a horizontal direction within an extent of movement of the screws along the horizontal oblong holes and within a limit of extent of elastic deformation of the elastic backup member. With this horizontal relative movement, thermal contraction and expansion of top and bottom horizontal frame members is accommodated or canceled out which would otherwise result in a bending of the vertical frame members.

Abstract: A weathertight door assembly having a first sealing means on an outer frame for sealing the gaps between the outer frame and the periphery of a pair of doors when the latter is closed, and a pair of coacting second and third sealing means on one of the doors for sealing the gap between inner vertical frame members of the doors when the latter are closed. A projection extends on and along one of the inner vertical frame members for covering the gap between the doors when the latter are closed. The second sealing means is supported on the projection and coextends with the length therewith. The third sealing means is supported on the said one inner vertical frame member and coextends with the length thereof. As the doors are closed, the third sealing means is sandwiched partly between the second sealing means and the other inner vertical frame member and partly between the latter and the first sealing means.