COUNTERBALANCED WINDOW OPERATORS

摘要

2093134 9209775 PCTABS00013 A counterbalanced window operator includes a rotatable drive member operatively connected to the pivoting end of the window by means of an arm member (29). A spring (40) occupying a fixed orientation is operatively connected to the arm member (29) to counterbalance the torque transmitted from the window to the arm member (29). In a preferred embodiment, double scissors arm members (250a and 250b) include a pair of first arm members (251a and 251b) that define a first plane and a pair of second arm members (252a and 252b) that define a second plane at an oblique angle relative to the first plane when the window is in an open position.