Patent ID: 6374580
Filing Date: 2002-04-23
Classification: B65B

Abstract:
In a rotary vacuum packaging machine for sequentially transferring unsealed packaged articles fed from a bag-forming and -filling packaging machine at regular intervals onto pressure-proof chambers that move along an endless track at regular intervals by means of rotation of a rotor driven by a main motor, and for vacuum-sealing said unsealed packaged article inside each of said moving pressure-proof chambers, wherein individual servo motors respectively operate a corresponding component of the bag-forming and filling packaging machine, the individual servo motors including a first motor for transferring a band-shaped film to form it into a tube through cylinder-forming means, a method for controlling operation of the bag-forming and filling vacuum packaging machine, comprising the steps of:using a main controller for calculating a number of pulses generated by said main motor in order to monitor a transfer pitch of said pressure-proof chambers based on said number of pulses; and sending an arithmetic-operation signal to each control element connected to a corresponding one of the individual servo motors each operating a corresponding component of said bag-forming and -filling packaging machine, in order to simultaneously correct the servo motors so that their rotations are constantly proportional to variations in the transfer pitch of said pressure-proof chambers caused by variations in loads on said rotor, so that rotation of each said individual servo motor operating a corresponding component of the bag-forming and filling packaging machine is controlled so as to be proportional to the transfer pitch of said pressure-proof chambers.