Hydraulic door actuator

Abstract

A hydraulic door drive includes a working piston and an auxiliary separated by a spring in a common piston space. A hydraulic circuit connects a first pressure space on a side of working piston facing away from the spring, and a second working space on a side of the auxiliary piston facing away from the spring. A power and control unit controls the pressure generated in the hydraulic circuit by a motor driven pump based on the position of the working piston, as determined by a position transducer.

Dependencies are inferred from the claim text.