| 摘要 |
Draw rollers for striplike materials (especially paper or cardboard strips, plastic or metal foils), having a sheath (1) that can rotate around a fixed inner component, whereby said sheath is provided with air holes along the entire surface thereof, are already known per se. A vacuum chamber (8) is arranged in the winding area of the strip. Said vacuum chamber (8) can be subjected to an underpressure. According to the invention, another vacuum chamber (8) is arranged inside the sheath (1) in the running direction of said strip (2) directly in front of the vacuum chamber (8), whereby the underpressure in the second vacuum chamber is greater than the underpressure in the first vacuum chamber (8) and is independent thereof. The upstream second vacuum chamber (8) enables the separating layer of air adhering to the strip (2) to be suctioned in a targeted manner, whereby the contact surface of the strip (2)/roller remains large enough to transmit high drawing forces. |
