Extruded plastic window frame

Claim 1

In a sliding sash window; a generally vertically arranged, rectangular window frame having inner and outer sides and composed of a pair of relatively spaced apart upright stiles and upper and lower rails miter-joined at the corners of said frame to said stiles, each of said stiles and rails being identical in cross section and each consisting of a generally elongated, integral, synthetic resin extrusion which includes a generally flat, intermediate cross web, a mounting web extending perpendicularly outwardly from said coextensive with said cross web, and a plurality of relatively spaced apart channel-forming webs projecting perpendicularly from and coextensive with the side of said cross web opposite said mounting web; the mounting webs of said stiles and rails defining on said window frame a substantially continuous, outer, marginal mounting flange for said frame, and the channel-forming webs of said stiles and rails defining in said window frame a plurality of relatively offset, inwardly opening sash-receiving channels, one of the channelforming webs of said stiles and rails having a return bend thereon defining on the inner side of said window frame a continuous, spline-receiving groove, and the other of the channel-forming webs of said stiles and rails being formed with integral, longitudinally coextensive, flexible weather-strips angled inwardly of the channels of said frame for sealing engagement with sash received therein.