Enerpac Tool Group Corp.
Hybrid spring for a hydraulic cylinder

Abstract:

A piston cylinder assembly includes a housing defining a housing cavity, a piston movably supported by the housing, and a spring return assembly connected between the housing and the piston. A fluid supplied to the housing cavity is operable to cause the piston to extend out of the housing and the spring return assembly is operable to cause the piston to retract into the housing. The spring return assembly includes a first spring member connected at one end to the housing and having an opposite end. The first spring member is operable to apply a first spring force. A second spring member is connected at one end to the piston and has an opposite end. The second spring member is operable to apply a second spring force. The opposite end of each of the first second spring members cooperate to apply the first and second spring forces in series.