A lock assembly for a ventilating window having a sash arranged to be openable with respect to a main frame by pivotal movement about a pivot axis parallel to a pair of opposed sash members, said lock assembly comprising: a casing, a locking arm, a lock mechanism arranged in said casing for enabling the locking arm to be displaceable between a first position defining an unlocked position and a second position defining a locked position, - said lock mechanism comprising an actuator slide operably connected to said locking arm via a link member pivotally connected to said locking arm at a first pivotal connection and to said actuator slide at a second pivotal connection, - - said actuator slide having three stable positions, namely a locked position with the locking arm in the locked position, an unlocked position with the locking arm in the unlocked position and an intermediate position between said unlocked position and said locked position with the lock arm in the locked position when the actuator slide is in the intermediate position, - a first wire spring connected at a first end thereof to said locking arm and connected at a second end thereof to said casing, whereby the distance between said first end and said second end changes when the lock mechanism moves to another position, - a second wire spring connected at a first end thereof to said link member and connected at a second end thereof to said actuator slide, - characterized in said first wire spring comprising three portions between said two ends, namely a middle portion and two outer portions, wherein the middle portion is directed roughly parallel with a line connecting the two ends and/or the outer portions comprising a part that is directed roughly at a right angle with a line connecting the two ends. a casing, a locking arm, a lock mechanism arranged in said casing for enabling the locking arm to be displaceable between a first position defining an unlocked position and a second position defining a locked position, - said lock mechanism comprising an actuator slide operably connected to said locking arm via a link member pivotally connected to said locking arm at a first pivotal connection and to said actuator slide at a second pivotal connection, - - said actuator slide having three stable positions, namely a locked position with the locking arm in the locked position, an unlocked position with the locking arm in the unlocked position and an intermediate position between said unlocked position and said locked position with the lock arm in the locked position when the actuator slide is in the intermediate position, - a first wire spring connected at a first end thereof to said locking arm and connected at a second end thereof to said casing, whereby the distance between said first end and said second end changes when the lock mechanism moves to another position, - a second wire spring connected at a first end thereof to said link member and connected at a second end thereof to said actuator slide, - characterized in said first wire spring comprising three portions between said two ends, namely a middle portion and two outer portions, wherein the middle portion is directed roughly parallel with a line connecting the two ends and/or the outer portions comprising a part that is directed roughly at a right angle with a line connecting the two ends. - said lock mechanism comprising an actuator slide operably connected to said locking arm via a link member pivotally connected to said locking arm at a first pivotal connection and to said actuator slide at a second pivotal connection, - - said actuator slide having three stable positions, namely a locked position with the locking arm in the locked position, an unlocked position with the locking arm in the unlocked position and an intermediate position between said unlocked position and said locked position with the lock arm in the locked position when the actuator slide is in the intermediate position, - - said actuator slide having three stable positions, namely a locked position with the locking arm in the locked position, an unlocked position with the locking arm in the unlocked position and an intermediate position between said unlocked position and said locked position with the lock arm in the locked position when the actuator slide is in the intermediate position, - a first wire spring connected at a first end thereof to said locking arm and connected at a second end thereof to said casing, whereby the distance between said first end and said second end changes when the lock mechanism moves to another position, - a second wire spring connected at a first end thereof to said link member and connected at a second end thereof to said actuator slide, - characterized in said first wire spring comprising three portions between said two ends, namely a middle portion and two outer portions, wherein the middle portion is directed roughly parallel with a line connecting the two ends and/or the outer portions comprising a part that is directed roughly at a right angle with a line connecting the two ends.