Patent ID: 6889501
Filing Date: 2005-05-10
Classification: E05F,E05Y,F15B

Abstract:
1. A hydraulic swinging-leaf door drive for swinging doors, comprising: an actuating piston movably arranged in a piston space defined by a cylinder and connectable for acting on a drive shaft of a swinging door, said piston dividing said piston space into a rear-piston space and a front space on opposing sides of said piston; a hydraulic circuit connected to said actuating piston; a hydraulic pump connected to said hydraulic circuit for acting on said actuating piston through said hydraulic circuit, a suction side of said hydraulic pump being connected to said rear piston space and a pressure side of said hydraulic pump being connected to the front piston space, wherein hydraulic circuit is a closed circuit, said piston defining a tank space therein, said tank space being connected to said closed hydraulic circuit by a connecting line.