Patent ID: 7815023
Filing Date: 2010-10-19
Classification: C08L,E05F,E05Y,Y10T

Abstract:
1. An apparatus for opening and closing a door leaf, the apparatus comprising: a housing made of polyoxymethylene plastic, the housing having a recess; a piston made of polyoxymethylene plastic, the piston having a toothed rack and being arranged for movement in the recess; a closing shaft comprising a pinion which engages the rack to drive the piston in the recess; and a closing spring arranged in the recess acting on the piston oppositely to the closing shaft; wherein the toothed rack is made of metal and is embedded in the piston by molding the polyoxymethylene plastic around the rack so that the rack and the piston form a one-piece element; and wherein the housing is fitted with bearing shells which support the closing shaft, the bearing shells being made of polyoxymethylene plastic, wherein the bearing shells being press fit into the housing and welded to the housing by ultrasonic welding.