Hydraulic cylinder for a hydraulic drawing cushion

US9038431B2 · kind B2 · utility

Assignee

• SCHULER PRESSEN GMBH & CO. KG · DE

Inventors

• Michael Micklisch · Eppingen, DE
• Markus Müller · Männedorf, CH

Key dates

• Filing date: Apr 29, 2011
• Grant date: May 26, 2015
• Expiry date: Jun 1, 2033

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B2211/775
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

The invention resides in a hydraulic cylinder (23) for a hydraulic drawing cushion (20) of a drawing press (10). The hydraulic cylinder (23) includes a first operating chamber (47), a second operating chamber (48), and a third operating chamber (53). An annular piston (45) with a first piston surface area (49) and a second piston surface area (50) separates the first operating chamber (47) from the second operating chamber (48). The first and the second piston surfaces (49, 50) have the same size. A front surface of the piston rod (33) forms a third piston surface (54) which is larger than the first and second piston surfaces. The third piston surface (54) delimits the third operating chamber (53) of the hydraulic cylinder (23). The first and the second operating chambers (47, 48) are provided for controlling the position and/or the movement of the piston rod (33). The third operating chamber (53) serves to control the metal sheet clamping force of the drawing press via the piston rod (33).