Patent ID: 9283599
Filing Date: 2016-03-15
CPC Classification: B21B

Claim Text:
1. A process for rolling a hollow body having an inner cavity to obtain a rolled tube using at least one mandrel, wherein there is provided a rolling plant comprising a rolling mill with a plurality of rolling stands, defining a rolling axis, a rolling direction, an inlet side defined upstream of the rolling mill, and an outlet side defined downstream of the rolling mill, the rolling direction going from the inlet side to the outlet side, wherein a first loading device to load the hollow body, a first unloading device to unload the mandrel and a first mandrel conveyor are provided on the inlet side, and a second unloading device to unload the rolled tube, a second loading device to load the mandrel and a second mandrel conveyor are provided on the outlet side, said process comprising, in a rolling cycle, the following stages: loading the hollow body along the rolling axis from the inlet side by means of said first loading device, loading the at least one mandrel along the rolling axis from the outlet side by means of said second loading device and connecting a first end area of the at least one mandrel to said second mandrel conveyor, axially translating the at least one mandrel along the rolling axis through the rolling mill and through the inner cavity of the hollow body, integrally fixing a second end area of the at least one mandrel to said first mandrel conveyor and releasing the first end area of the at least one mandrel from said second mandrel conveyor, rolling the hollow body by passing the same through rolling stands of the rolling mill in the rolling direction, so as to obtain the rolled tube at the outlet side while simultaneously feeding the mandrel by means of the first mandrel conveyor in a direction opposite to the rolling direction, completely extracting the mandrel from within the rolled tube and from the rolling mill, whereby the mandrel is on the inlet side and ready to be removed from the rolling axis, removing the mandrel from the rolling axis by means of the first unloading device, and conveying the mandrel from the inlet side to the outlet side for a next rolling cycle.