Motor operator for doors and windows

An electrical actuator device for opening and closing doors and windows having an openable frame between a closed position and a ventilation or tilted position comprises an electric drive unit with a reversible motor and associated transmission. The drive unit is accommodated within a housing on a frame member serving to receive a locking mechanism, and the transmission functionally engages a locking mechanism mounted in the frame member and a transfer element, respectively, which by means of a coupling fixture is connected with the main frame, the transmission having a first engagement member and a second engagement member for engaging a first carrier member and a second carrier member, respectively. The first carrier member is functionally coupled with the square shaft and engageable by the transmission for reversible pivoting rotation of the square shaft between positions corresponding to a locking position and a released position of the locking mechanism, and the second carrier member is connected with the transfer element and engageable by the transmission for moving said transfer element in an opening direction in continuation of rotation of said operator shaft to release the locking mechanism and in a closing direction prior to rotation of the square shaft to provide locking engagement of the locking mechanism.