Non-backdriving actuator for opening and closing a window sash
AssigneeAmerock Corporation
InventorRobert F. Lense
Life of this patent
Estimating the term…
Abstract
A shaft of a window actuator is operable to open and close a casement window sash when the shaft is rotated either by a hand crank or by a motor from inside of the premises. The shaft is automatically locked against rotation if a backdriving force is applied to the actuator from outside the premises. This prevents an open sash from being buffeted by wind and from being pulled open further by a potential intruder.
Claims10
An actuator for moving a window sash between open and closed positions, said actuator comprising a housing, a shaft assembly rotatably supported by said housing, said shaft assembly having first and second end portions and having a section located between said end portions, a linkage connected between said shaft assembly and said sash and operable to move said sash toward said open position when said shaft section is rotated in one direction and to move said sash toward said closed position when said shaft section is rotated in the opposite direction, the improvement in said actuator comprising means for restricting rotation of said shaft section in either direction when torque of predetermined magnitude is applied to said first end portion of said shaft assembly without being transmitted to said first end portion from said second end portion, said means permitting said shaft section to rotate in either direction when torque of the same magnitude is applied to said second end portion of said shaft assembly without being transmitted to said second end portion from said first end portion.
A non-backdriving actuator for moving a window sash between open and closed positions, said actuator comprising a housing, first and second shafts rotatably supported by said housing, a linkage connected between said first shaft and said sash and operable to move said sash toward said open position when said first shaft is rotated in one direction and to move said sash toward said closed position when said first shaft is rotated in the opposite direction, means permitting said shafts to rotate relative to one another through a limited angular distance and thereafter coupling said shafts together for rotation in unison, means for restricting rotation of said first shaft in either direction when torque is applied to said first shaft without being transmitted to said first shaft from said second shaft, and cam means responsive to relative rotation of said shafts for disabling said restricting means so as to permit rotation of said first shaft in either direction when torque is applied to said second shaft without being transmitted to said second shaft from said first shaft.
Dependencies are inferred from the claim text.