Patent ID: 8584502
Filing Date: 2013-11-19
Classification: B21D

Abstract:
1. A forming device for cup-shaped hollow bodies having a machine frame, a drive device, a workpiece rotary table for accommodating workpiece holders which are formed to fix hollow bodies and having a tool holder for accommodating processing tools wherein the workpiece rotary table and the tool holder face one another and can be turned about a rotational axis in relation to one another and can be linearly moved in relation to one another along the rotational axis wherein the drive device is designed for providing a rotary step movement and a cyclical linear movement between the workpiece rotary table and the tool holder in order to enable the hollow bodies to be formed by means of the processing tools in a plurality of consecutive processing steps, and wherein the workpiece holder has a recess for accommodating a hollow body and a wall section which limits the recess in certain areas, has an adjustable geometry, which is designed to narrow the cross-section of the recess in order to enable the hollow body to be fixed on the workpiece holder wherein the wall section with the adjustable geometry is formed by a flexible membrane, which limits a fluid channel formed in the workpiece holder, in certain areas, wherein the flexible membrane comprises two substantially parallel legs and an interior surface area disposed between the two legs, the legs and the interior surface area defining a U-shaped cross-section, the U-shaped cross-section opening outwardly in the radial direction, in a cross-sectional plane, which comprises a longitudinal axis of the recess, and wherein the interior surface area of the flexible membrane delimits the recess of the workpiece holder in certain areas and moves upon pressurization of the fluid channel in both a radially inward direction and in an axial direction parallel to the longitudinal axis of the recess in the opposite direction of the mouth opening for pressing the hollow body into the workpiece holder.