US Patent 7051403 Electromechanical swing leaf operator

The invention relates to an electromechanical swing leaf operator having a door closer (1) with an eccentrically supported pinion (6) that presents a circular rolling curve and meshes with a toothed rack (5) being disposed at a piston (4), whereby a particular execution of the rolling curve and of the teeth (9) of the toothed rack (5) in adaptation to a toothing of the pinion (6) is achieved. With the intention to realize an optimized moving course of the piston (4) in the housing (2) of the door closer (1) an improved execution of the delayed closing operation is provided.