Patent ID: 6378277
Filing Date: 2002-04-30
Classification: B65B

Abstract:
A vertical sealing device for a vertical type forming, filling and closing machine for flexible packages, said machine including a filling tube which guides a cylindrically formed packaging material and which is used for intermittently filling at least one article into said packaging material, the packaging material being formed such that both side edges thereof are superposed on each other so as to form a seam extending along said filling tube, said machine comprising:detecting means for detecting a non-filling operation of the article and a restart of the filling operation of the article after the non-filling operation is detected, respectively; a feed unit for feeding the packaging material along said filling tube, said feed unit including a constant mode for feeding the packaging material at a steady speed during a normal operating state of said machine, a deceleration mode for decelerating the packaging material from the steady speed state when said non-filling operation is detected to a low speed state, and an acceleration mode for accelerating the packaging material from said low speed state thereof to the steady speed state when said restart of the filling operation is detected; a center heat sealer for heating and sealing the seam of the packaging material, said center heat sealer being in contact with the seam and an open position where said center heat sealer is spaced from the seam; and control means for controlling operation of each of said center heat sealer in response to the operation of said feed unit, said control means having a stop timing for moving said center heat sealer from the close position toward the open position when the operation of said feed unit is shifted from said constant mode to said deceleration mode, and a start timing for moving said center heat sealer from the open position toward the close position when the operation of said feed unit is shifted to said constant mode through said acceleration mode, and at least one of said stop timing and start timing being located within the corresponding one of said deceleration mode and acceleration mode; and wherein each of said acceleration mode and deceleration mode has a temporary suspension region for suspending the deceleration or acceleration of the packaging material so as to maintain the packaging material at a speed, respectively.