Patent ID: 7555871

Claim:
A frame for a sliding window, comprising: an elongated base piece and a pillow block piece that together form part of one of a sill section and a head section of the sliding window, the base piece having inner and outer side walls defining a first channel in which a rail runs in a longitudinal direction of the base piece and on which an operable half of the window is to slide, the inner and outer side walls having respective flanges extending laterally inwardly to define a channel opening, the base piece further having a second channel in front of the first channel to receive therein a fixed half of the window, and the pillow block piece having a laterally open cavity running in a longitudinal direction of the pillow block piece, a linear bearing to be fitted in the cavity, and the pillow block piece to be installed onto the rail in the first channel so that the bearing is in contact with the rail and so that a portion of the pillow block piece extends in a vertical direction through the channel opening, the pillow block piece having first and second wings that, when the pillow block piece is installed on the rail, are disposed within the first channel and extend laterally beyond each side of the channel opening so that the pillow block piece is retained vertically within the first channel even if dislodged from the rail.