Low profile high performance casement and awning window keeper

A locking device for use in a window having a frame defining an opening and a sash hinged to the frame and selectively shiftable to close the opening, the locking device comprising:

• a keeper including a base plate with a pair of spaced apart wings extending upwardly therefrom, each wing angled inwardly at an angle of from 50° to 70° relative to the base plate and including a distal end portion oriented substantially parallel with the base plate, the distal end portions of the wings defining a gap therebeween, the spaced apart wings including a first wing and a second wing, wherein a length of the first wing at the distal end portion is less than a length of the first wing at a proximal end portion thereof, and a length of the second wing at the distal end portion is less than a length of the second wing at a proximal end portion thereof, the first wing including a first and second entrance ramp, and the second wing including a third and fourth entrance ramp, wherein each of the entrance ramps presents a curved structure presenting a ramp angle;
• and
• a locking lug having a head and a shaft, a width dimension of the head being greater than a width dimension of the shaft, the width dimension of the head being greater than a width dimension of the gap, and a width dimension of the shaft being equal to or less than the width dimension of the gap, wherein the keeper is attached with the base plate abutting one of the sash or the frame and the locking lug is coupled to a locking mechanism on the other of the sash or the frame, and wherein the locking lug is selectively shiftable with the locking mechanism between a first position wherein the locking lug is received in the gap between the spaced apart wings of the keeper to secure the sash to the frame, and a second position wherein the locking lug is clear of the keeper to enable the sash to be shifted away from the frame.