Bag filling and packaging method and bag filling and packaging apparatus

Abstract

A bag filling and packaging system including gripper pairs around a rotating table so that the grippers of each gripper pair grip two side edges of a bag on which various packaging processes are performed. A gripper distance adjustment auxiliary cam is provided to ascend and descend relative to a gripper distance setting cam for setting distance between grippers. A roller rolls on the two cams as the table rotates, and the distance between the grippers changes in response to the height of the roller by a transmission mechanism. An apparent bag width is measured prior to gripping a bag, the height of the gripper distance adjustment auxiliary cam is controlled according to this measured value, and the distance between grippers in a bag supply process is adjusted accordingly, the amount of part gripped by the grippers at side edges of a bag thus being constant for all bags.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a bag filling and packaging apparatus including a plurality of gripper pairs, which are provided at equal distance about a carrying member (table or chain) that rotates continuously or intermittently along a circular path, for gripping both (left and right) side edges of a bag, wherein bags are supplied to the gripper pairs while the carrying member makes one revolution, and the bags gripped by the gripper pairs are sequentially subjected to such packaging processes as bag mouth opening, contents charging, and bag mouth sealing.[0003]2. Description of the Related Art[0004]A typical bag filling and packaging apparatus includes a table that has a plurality of gripper pairs provided about the circumference and rotates intermittently; and in this bag filling and packaging apparatus, various packaging processes are sequentially performed at various stop positions. Such processes include suppl...

AI Technical Summary

Benefits of technology

[0015]Accordingly, the object of the present invention is to solve the above-described problems with the conventional art conventional art, and the present invention provides a bag filling and packaging method and apparatus which is free of the problems of the conventional art, even in cases that bags having warping or distortion in the bag surfaces and having bag width of below the nominal value are involved.

[0016]More specifically, the present invention is for a bag filling and packaging method and apparatus in which a plurality of gripper pairs, for gripping the left and right side edges of bags, are provided at equal distance about a carrying member that rotates continuously or intermittently along a circular path, and while the carrying member makes one revolution, bags are supplied to the gripper pairs, the bags gripped by the gripper pairs are subjected sequentially to such packaging processes as bag mouth opening, contents charging, and bag mouth sealing; and the present invention can be categorized into four: a bag filling and packaging method (1) and apparatus (2) that maintains the amount of part gripped by a gripper pair at bag side edges constant, and a bag filling and packaging method (3) and apparatus (4) that, when the distance of two grippers (of a gripper pair) is widened and the bag mouth is thus tensioned, maintains the degree of tension in the bags constant.

[0045]as the above-described gripper distance adjustment means, a gripper distance adjustment auxiliary cam and a drive mechanism are provided, wherein the gripper distance adjustment auxiliary cam has on its upper surface a cam surface and is provided so as to be ascendable and descendable relative to the gripper distance setting cam at predetermined positions in the circumferential direction of the gripper distance setting cam, and the drive mechanism causes the gripper distance adjustment auxiliary cam to ascend and descend;

[0048]As seen from the above, according to the present invention, even a case that there is warping or distortion in the bag surface, and even when there are bags that have an apparent bag width which is smaller than the nominal value, a danger that a bag comes away from the grippers when the amount of part gripped by grippers is small and contents are charged is prevented; and further, such problems as defective printing, defective air removal, defective gas replacement, and defective seals, that are caused when bag mouth tension is not sufficiently obtained, is also prevented.

Problems solved by technology

However, depending on the types of bags, some have bag surfaces that are warped or distorted (such warping or distortion often occurring in spout-equipped bags and zipper-equipped bags).

When such bags are used in packaging, problems would arise.

Since the amount of parts gripped by grippers (a width of a bag edge that is gripped) is small, it is difficult to sufficiently tension the bag mouth when, for instance, sealing the bag (the bag mouth will not be sufficiently tensioned even when the distance between the grippers (of a gripper pair) is widened to the reference value).

When the amount of part gripped by grippers is small, the gripping force is weak, and there is a danger that the bag comes away from the grippers when contents are charged therein.

Furthermore, when the bag mouth is not sufficiently tensioned, the bag mouth will not be closed sufficiently, making air removal and gas replacement defective, and causing sealing defects.

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