Tilt-lock slide for window sash

Claim 1

In combination with a window frame presenting opposite vertical sides which define respective vertically elongated tracks with vertically elongated openings which face toward each other at the inside of the window frame, each of said opposite vertical sides of the window frame having opposite lateral side walls along the respective track which extend laterally outward from the respective vertically elongated opening at the inside of the window frame, and wherein said window frame at each side presents a pair of vertically elongated lips along the front and back of said vertically elongated opening at the inside of the frame, with the lips of each pair extending toward each other substantially perpendicularly away from said opposite side walls of the respective track in the window frame to confine said slide member and said spring in the respective track, and a transverse side wall at the outside of the frame extending perpendicularly between said opposite lateral side walls; and a window sash fitting closely and slidably inside said frame; the improvement which comprises: a respective flat leaf spring with a spirally wound upper end fastened to said window frame and disposed in each of said tracks with the axis of said spirally wound upper end parallel to said lateral side walls, each said spring being extensible downward along the respective track substantially contiguous to and parallel to one of said lateral side walls thereof and having a width extending across said last-mentioned lateral side wall which is substantially greater than its thickness front-to-back of the window frame; and a respective one-piece resilient slide member with a cam-shaped periphery fastened to the lower end of each spring and disposed in the respective track in the window frame, each said slide member being rigidly coupled to the window sash for movement in unison therewith vertically along the window frame and pivotally with respect to the window frame, each said slide member having a minimum diameter extending substantially horizontally when the window sash is vertical and being readily slidable vertically along the respective window frame track when its minimum diameter is substantially horizontal, and each slide member having a portion of larger diameter which is frictionally wedged between said opposite lateral side walls of the respective window frame track when the slide is turned by tilting the window sash substantially from its vertical position, whereby to lock the window sash against vertical movement in the window frame when so tilted; said slide member having an axis substantially parallel to said lateral side walls and having means forming a substantially C-shaped opening therein extending about said axis which makes said slide member resiliently yieldable from both lateral side walls when wedged between said opposite lateral side walls to assist in said locking action; and the lower end of said spring being partially wrapped around said periphery of said slide member when said slide member is turned.