The machine based on this principle combine the advantages of three roll pyramid type, three roll initial pinch type and four roll

pinch type machines.

Highest degree of pre-bending can be achieved and only the smallest possible width of flat remains.

An error in pre pinching can be corrected even after the shell is completed.

It can pre-pinch and roll the plate without removing the plate from machine after first insertion.

Inclined movement of bottom rolls provides wider bending span as the plate thickness increases, and better grip in thinner plates.