Casement window with multi-angle locking window sash

A casement window with multi-angle locking sash, comprising a window frame and a window sash, wherein said window sash accomplishes connecting with said window frame, and opening or closing by a window hinge mechanism and a locking mechanism, and said window sash is capable of locking at any angle with said window frame, wherein:

• said window hinge mechanism comprises a quadrilateral link mechanism, a movable sliding block, a gear and a hinge base,
• wherein said hinge base is fixed on said window frame, a concave sliding groove is provided on said hinge base, said movable sliding block is provided in said concave sliding groove, a wheel axle is provided on said movable sliding block, and said gear is provided on said wheel axle,
• wherein said quadrilateral link mechanism comprises a stationary swing rod, a movable swing rod, a link rod and a movable rod, wherein a first end of said stationary swing rod is hinged on said hinge base, a second end of said stationary swing rod is hinged on said movable rod, a first end of said link rod and a first end of said movable swing rod are hinged with said movable sliding block, a second end of said movable swing rod is hinged with said movable rod, a second end of said link rod is hinged with said stationary swing rod, wherein said movable rod is fixed with said window sash;
• said locking mechanism comprises a screw rod, an axial plane is provided on said screw rod, a screw thread is provided on a circumferential surface of said screw rod, two ends of said screw rod are respectively hinged on said hinge base via a stationary base, said screw rod accomplishes locking said window sash by engaging said screw thread with said gear on said movable sliding block, and said screw rod accomplishes opening or closing said window sash by rotating said axial plane corresponding to said gear on said movable sliding block.