PURPOSE: To prevent the occurrence of an empty bag, by synchronizing the speed and phase of both a motor for feeding packaging material and a motor for sealing bag end with those of a motor for driving conveyor.
CONSTITUTION: The speed and phase of both motors B and C are gradually increased until they are synchronized with the constant speed and phase of a motor A for driving a conveyor 12 and thereafter the operation of these two motors at a constant speed is continued. Upon detection of a missing article by a missing article detecting sensor 42, the motor B for feeding packaging material 16 and the motor C for driving sealers 40, after stand by pending the coincidence of current supply position Q1 of an article 10 to be packaged with cycle terminating Q0, are gradually decreased in speed and brought to a stop and, after their stopping for a predetermined time, restarted at an increased speed. More specifically, since both the motors B and C do not make an abrupt instantaneous stopping and restarting, even if the missing article 10 in the bag is detected, an impulsive vibration and shock to a packaging machine is not created, thereby preventing the positional shift of the article 10 effectively.
HATANO MASATO
SUZUKI SHIGEKI
