Patent ID: 8689531

Claim:
A bag making and packaging machine comprising: a conveying unit configured and arranged to continuously convey a tubular packaging material; a transverse sealing mechanism having a pair of sealing jaws configured and arranged to revolvingly move while following annular loci to seal the tubular packaging material in a transverse direction with respect to a conveyance direction of the tubular packaging material, the transverse sealing mechanism further having shutter members configured and arranged to touch the tubular packaging material before the sealing jaws touch the tubular packaging material to prevent entry of contents from above into a space inside a transverse sealing target portion of the tubular packaging material at which the tubular packaging material is sealed by the sealing jaws immediately after the shutter members touch the tubular packaging material; a gusset forming mechanism having a pair of folding members configured and arranged to be pressed against side portions of the tubular packaging material to form gussets in the side portions of the tubular packaging material while the folding members move along the conveyance direction of the tubular packaging material before the transverse sealing mechanism seals the tubular packaging material, the gusset forming mechanism being configured and arranged to annularly move each of the folding members and parts supporting each of the folding members, the gusset forming mechanism further being configured and arranged to revolvingly move each of the folding members so as to match a conveyance speed of the tubular packaging material while revolvingly moving them along the conveyance direction on the tubular packaging material continuously conveyed when forming the gussets, lower ends of the folding members are positioned lower than the shutter members when the shutter members have reached the first state; and a control unit configured to control operations of the transverse sealing mechanism and the gusset forming mechanism, the control unit being configured to control the operation of the transverse sealing mechanism and the operation of the gusset forming mechanism so that the gussets are formed in the side portions of the tubular packaging material by the folding members before the shutter members reach a first state where the shutter members prevent entry of the contents from above into the space inside the transverse sealing target portion of the tubular packaging material.