Knuckle Joint Presses 

Knuckle Joint Linkage connects the upper and lower slides to creates and optimum motion curve . Since curve is transformed and retarded.

to a flat curve as the slide approaches BDC. Such slide motion curve can ensure material to be formed/forged to a desire forming quality due to the slowdown of slide speed and longer period of forming time.

Mechanical slide adjustment drive and hydraulic locking system ensures zero clearance of slide adjustment during operation, thus ensuring high quality of forged parts.

more detail see pdf