Patent ID: 7780111

Claim:
A roll storage module comprising: a storage roll; a band roll; a band extending between the storage roll and the band roll, the storage roll and the band roll being rotatable so that the band can be rolled around and unrolled from each roll; a storage roll motor for applying a rotational torque directly to the storage roll; a band roll motor for applying a rotational torque directly to the band roll; and a control system for controlling the motors so as to cause the band to roll on and unroll from the storage roll and the band roll respectively in a predetermined manner wherein the control system includes a processor for monitoring rotation of the band roll, and for calculating one or more parameters relating to the band based on the monitored band roll rotation thereby to control the band and storage roll motors to rotate their respective rolls in the predetermined manner, the parameters being selected from (1) the position of the band as it is rolled and unrolled, (2) the speed of the band, and (3) the tension on the band, wherein the position Ln of the band is computed by the processor in accordance with the formula: L ⁢ ⁢ n = 2 ⁢ π × n ⁡ ( R K + Th × n 2 ) where Ln is the length of the band wound on the band roll as a function of n; n is the number of revolutions made by the band roll since band end; RK is the band roll radius; and, Th is the band thickness.