Drawing roller unit with scavenging means

摘要

A drawing roller unit is constructed with a godet and an electric motor mounted on a common shaft. A passage is provided throughout the unit to convey a non-flammable scavenging gas through the motor and the godet to reduce the risk of explosion due to sparking by the electric motor and/or other electrical parts of the drawing roller. The gas introduced can leave the unit only through a narrow gap. The pressure of the gas is consequently above atmosphere pressure and prevents the entrance of air.