Patent ID: 6343436
Filing Date: 2002-02-05
Classification: E05F,E05Y,Y10T

Abstract:
A sliding sash drive assembly comprising:a. a rack gear having a side formed with teeth and adapted to be connected to the sash parallel to the direction of sash movement and held against longitudinal movement with respect to the sash, b. A drive unit adapted to be mounted on a frame element associated with the sash and extending in the direction of intended travel of the sash, the unit comprising: 1) a housing containing a drive motor having an output shaft and spur exterior of the housing, 2) an L-shaped engagement lever having a long arm and a short arm, a point on the short arm being pivotally attached to the housing or an axis parallel to the output shaft, 3) a rack guide pivotally attached to the short arm at a point spaced along the short leg from the first point, the guide embracing the rack from opposite sides and adapted, as the long leg is pivoted, to move the rack into engagement with the spur or out of engagement with the spur.