Self aligning piston rod

In a power actuated door operator for opening and closing a door, said door operator having a power inlet into a cylindrical body to drive a power piston, a hydraulic door closer piston with a rack gear for engaging with a pinion gear for operating a door control arm, a head separating said power piston in a chamber from said hydraulic door closer piston in a hydraulic chamber, a reciprocable rod extending through an opening in said head for transmitting pushing forces between said power piston and said hydraulic piston, and a spring for pushing said hydraulic door closer piston to provide closing force to said door control arm after said door has been opened by the door operator, the improvement, in combination with said door operator, comprising:

• means for enabling said reciprocable rod to move radially with respect to faces of said power piston and said hydraulic door closer piston to accommodate misalignments between said pistons, said rod, and the opening in said head.