Aluminum frame window with improved thermal insulation and method of making same

DETAILED DESCRIPTION I claim: 1.
An aluminum frame doublehung window comprising: a sill structure including: exterior and interior spaced aluminum structural members having mutually facing portions, said exterior member having an exposed flat top surface which slopes downward in an outward direction; a rigid thermally insulative insert extending between said exterior and interior members along the top of the space therebetween and having an exposed top surface which is co-planar with the flat top surface of said exterior member; poured and hardened thermally insulative fill material filling the space below said insert between said mutually facing portions; and a sash member which in its closed position abuts said flat top surface of said insert.
2.
The window according to claim 1 wherein the thermal break in said jamb is in contact with the top surface of said insert and has no direct contact with either of said exterior and interior members.
3.
The window according to claim 1 further comprising a thin plastic snap-on trim member disposed over the thermal fill material in the jamb thermal break to cover at least said first and second block surfaces.
4.
In a window according to claim 1, a jamb structure including a thermal break in a two-member jamb frame of the type in which adjacent portions of each jamb frame member are spaced by a poured and then hardened resinous thermally-insulative material block which is secured to the metal and which projects inwardly from the frame, said block having an inwardmost surface which is substantially parallel to said frame and wider than the minimum spacing between said members.
5.
The window according to claim 4 wherein at least one of said two jamb frame members includes a projecting section which projects inwardly of said frame at said thermal break, and wherein said thermal break surrounds the extremity of said projecting section.
6.
The window according to claim 4 wherein said two jamb frame members each include a projecting section which projects inwardly of said frame, the two projecting sections defining the minimum spacing between said frame members, and wherein said projections are embedded in and surrounded by said block