Window operator

An operator for controlling the movement of a window sash relative to a frame between open and closed positions, said operator comprising:

• a base attachable to a frame and having a first support surface with a slot therein, wherein said slot is formed within said base continuously from a first edge of said base to a second edge of said base so as to be capable of engaging a raised portion of a window to provide a means for allowing attachment of the operator to a window and to prevent substantial infiltration of air and water through the operator when said base is attached to a window and an aperture;
• a cover secured to said base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface;
• a post extending from said cover and through the aperture;
• an arm pivotally secured to said post and attachable to a sash to control the movement of a sash between open and closed positions;
• and,
• a worm drivably engaging said arm and having a worm shaft and a worm shoulder disposed on the worm shaft, said worm directly supported by the first and second surfaces at one end and the worm shoulder engaging the internal shoulder with the worm shaft protruding from the hole.