Patent ID: 7726073

Claim:
A shoe for supporting a window sash frame in an outer frame, the shoe being slidably received in a channel in the outer frame comprising a top, a bottom and side walls, the shoe comprising a cam having a cam body and an annulus, the cam having a wider diameter and a narrower diameter, first and second mating shoe portions, each portion having an opening in communication with an end of the shoe portion, the opening having a wider diameter and a narrower diameter complementary to the cam, whereby when the cam is rotated in the opening the cam expands the shoe portions laterally, the annulus surrounding the cam body and having along an axis parallel to an axis of rotation of the cam a wider thickness and a narrower thickness, and being seated in a cam seat circumscribing the opening and having along an axis parallel to an axis of rotation of the cam a wider thickness and a narrower thickness complementary to the annulus, such that when the cam is in a rest position with the wider diameter of the cam aligned with the wider diameter of the opening, the wider thickness of the annulus is aligned with the wider thickness of the cam seat and the first and second mating shoe portions are in an unlocked position, and the cam comprising a pivot receptacle for receiving a pivot pin of a window sash in rotationally fixed relation, such that pivoting the window sash rotates the cam, whereby when the window is pivoted out of a plane containing the outer frame, as the cam body expands the shoe portions laterally the annulus cooperates with the cam seat to force the shoe portions apart and causing the shoe to expand in a direction perpendicular to the lateral expansion.