Hydraulically actuated tube expander - uses piston with tapered skirt to connect expander to hydraulic ram

摘要

A tube expander consists of a number of segments (2) fitted around a tapered sleeve (1) of polygonal cross-section. The tapered sleeve (1) is attached to the piston rod (3) of a hydraulic ram by means of a thick walled sleeve (7) with a tapered bore (15) running into a cylindricl recess (11). A piston (10) with a tapered skirt (8) fits inside the thick-walled sleeve (7). When high pressure oil is applied to the inlet (12) the skirt (8) is pulled further into the tapered bore of the sleeve (7), so taht the skirt diameter is reduced causing it to exert a firm grip on the piston rod (3).