Patent attributes
A concentric machining device for a roller includes a movable upper base, a stationary lower base, two movable mold seats, two slide rods and four first hydraulic cylinders. Each of the mold seats has a forming mold inside, the forming mold has a fitting hole with an enlarged conical opening at the front side thereof, a locating shaft is received in the forming mold of the first mold seat and penetrates the fitting hole thereof and the first cylinder member, a clamping shaft is received in the forming mold of the second mold seat and penetrates the fitting hole thereof and the second hydraulic cylinder to connect with the fourth hydraulic cylinder. The roller is held by the bases and the shafts via two of the hydraulic cylinders and both ends of the roller are machined by the forming molds in the mold seats to provide squeezed and shrunk shapes once the mold seats are actuated by the other two hydraulic cylinders.