Patent ID: 7421874

Claim:
In an extrusion pressing having a cylinder beam, a press cylinder comprising: a cylinder housing fixed on the beam; a piston shiftable along an axis in opposite forward and rearward directions in the housing and defining with a rear end of the housing a pressurizable cylinder chamber; a rod projecting axially rearwardly through the rear wall of the housing and formed with an axially extending bore; a connection block fixed on the housing rearward of the piston; an axially extending tube in the bore fixed to the block; an axially extending sleeve in the bore surrounding the tube, forming with the tube an annular gap, forming with an inner surface of the bore an annular compartment, and also fixed to the block, the connection block being formed with respective passages opening into the tube and into the annular gap; and a head fixed to the tube and to the sleeve, slidable in the bore, and forwardly closing the tube, the annular gap, and the annular compartment.