Patent ID: 6938373

Claim:
Apparatus for maintaining a sliding window sash at an intended position along an axis perpendicular to a plane defined by a frame within which the sash slides, said frame having an inwardly facing surface which, when the sash is in the intended position, is opposite an outwardly facing surface of the sash, comprising: (a) means for defining an elongate trough, the elongate trough adapted to be disposed in a portion of the frame, said trough adapted to extend generally parallel to the plane defined by the frame and generally in a direction of intended sliding of the sash; (b) a blade defining a blade plane; (c) blade mounting structure adapted to mount the blade within a cavity in the sash said blade adapted to be disposed generally parallel to the plane defined by the frame, said blade disposed for pivotal movement between a first position, wherein said blade is adapted to be retracted within the outwardly facing surface of the sash, and a second position, wherein said blade is extended into said trough; (d) means for normally biasing said blade to said second position thereof; and (e) means for selectively retracting said blade to said first position thereof.